document_redaction / tools /custom_image_analyser_engine.py
seanpedrickcase's picture
Added regex functionality to deny lists. Corrected tesseract to word level parsing. Improved review search regex capabilities. Updated documentation
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import copy
import os
import re
import time
from copy import deepcopy
from dataclasses import dataclass
from typing import Any, Dict, List, Optional, Tuple, Union
import botocore
import cv2
import gradio as gr
import numpy as np
import pandas as pd
import pytesseract
from pdfminer.layout import LTChar
from PIL import Image
from presidio_analyzer import AnalyzerEngine, RecognizerResult
from tools.config import (
AWS_PII_OPTION,
CONVERT_LINE_TO_WORD_LEVEL,
DEFAULT_LANGUAGE,
HYBRID_OCR_CONFIDENCE_THRESHOLD,
HYBRID_OCR_PADDING,
LOCAL_OCR_MODEL_OPTIONS,
LOCAL_PII_OPTION,
OUTPUT_FOLDER,
PADDLE_DET_DB_UNCLIP_RATIO,
PADDLE_MODEL_PATH,
PADDLE_USE_TEXTLINE_ORIENTATION,
PREPROCESS_LOCAL_OCR_IMAGES,
SAVE_EXAMPLE_HYBRID_IMAGES,
SAVE_PAGE_OCR_VISUALISATIONS,
SAVE_PREPROCESS_IMAGES,
SAVE_VLM_INPUT_IMAGES,
SELECTED_MODEL,
TESSERACT_SEGMENTATION_LEVEL,
TESSERACT_WORD_LEVEL_OCR,
VLM_MAX_DPI,
VLM_MAX_IMAGE_SIZE,
)
from tools.helper_functions import clean_unicode_text
from tools.load_spacy_model_custom_recognisers import custom_entities
from tools.presidio_analyzer_custom import recognizer_result_from_dict
from tools.run_vlm import extract_text_from_image_vlm
from tools.secure_path_utils import validate_folder_containment
from tools.secure_regex_utils import safe_sanitize_text
from tools.word_segmenter import AdaptiveSegmenter
if PREPROCESS_LOCAL_OCR_IMAGES == "True":
PREPROCESS_LOCAL_OCR_IMAGES = True
else:
PREPROCESS_LOCAL_OCR_IMAGES = False
try:
from paddleocr import PaddleOCR
except ImportError:
PaddleOCR = None
# --- Language utilities ---
def _normalize_lang(language: str) -> str:
return language.strip().lower().replace("-", "_") if language else "en"
def _tesseract_lang_code(language: str) -> str:
"""Map a user language input to a Tesseract traineddata code."""
lang = _normalize_lang(language)
mapping = {
# Common
"en": "eng",
"eng": "eng",
"fr": "fra",
"fre": "fra",
"fra": "fra",
"de": "deu",
"ger": "deu",
"deu": "deu",
"es": "spa",
"spa": "spa",
"it": "ita",
"ita": "ita",
"nl": "nld",
"dut": "nld",
"nld": "nld",
"pt": "por",
"por": "por",
"ru": "rus",
"rus": "rus",
"ar": "ara",
"ara": "ara",
# Nordics
"sv": "swe",
"swe": "swe",
"no": "nor",
"nb": "nor",
"nn": "nor",
"nor": "nor",
"fi": "fin",
"fin": "fin",
"da": "dan",
"dan": "dan",
# Eastern/Central
"pl": "pol",
"pol": "pol",
"cs": "ces",
"cz": "ces",
"ces": "ces",
"hu": "hun",
"hun": "hun",
"ro": "ron",
"rum": "ron",
"ron": "ron",
"bg": "bul",
"bul": "bul",
"el": "ell",
"gre": "ell",
"ell": "ell",
# Asian
"ja": "jpn",
"jp": "jpn",
"jpn": "jpn",
"zh": "chi_sim",
"zh_cn": "chi_sim",
"zh_hans": "chi_sim",
"chi_sim": "chi_sim",
"zh_tw": "chi_tra",
"zh_hk": "chi_tra",
"zh_tr": "chi_tra",
"chi_tra": "chi_tra",
"hi": "hin",
"hin": "hin",
"bn": "ben",
"ben": "ben",
"ur": "urd",
"urd": "urd",
"fa": "fas",
"per": "fas",
"fas": "fas",
}
return mapping.get(lang, "eng")
def _paddle_lang_code(language: str) -> str:
"""Map a user language input to a PaddleOCR language code.
PaddleOCR supports codes like: 'en', 'ch', 'chinese_cht', 'korean', 'japan', 'german', 'fr', 'it', 'es',
as well as script packs like 'arabic', 'cyrillic', 'latin'.
"""
lang = _normalize_lang(language)
mapping = {
"en": "en",
"fr": "fr",
"de": "german",
"es": "es",
"it": "it",
"pt": "pt",
"nl": "nl",
"ru": "cyrillic", # Russian is covered by cyrillic models
"uk": "cyrillic",
"bg": "cyrillic",
"sr": "cyrillic",
"ar": "arabic",
"tr": "tr",
"fa": "arabic", # fallback to arabic script pack
"zh": "ch",
"zh_cn": "ch",
"zh_tw": "chinese_cht",
"zh_hk": "chinese_cht",
"ja": "japan",
"jp": "japan",
"ko": "korean",
"hi": "latin", # fallback; dedicated Hindi not always available
}
return mapping.get(lang, "en")
@dataclass
class OCRResult:
text: str
left: int
top: int
width: int
height: int
conf: float = None
line: int = None
model: str = (
None # Track which OCR model was used (e.g., "Tesseract", "Paddle", "VLM")
)
@dataclass
class CustomImageRecognizerResult:
entity_type: str
start: int
end: int
score: float
left: int
top: int
width: int
height: int
text: str
color: tuple = (0, 0, 0)
class ImagePreprocessor:
"""ImagePreprocessor class. Parent class for image preprocessing objects."""
def __init__(self, use_greyscale: bool = True) -> None:
self.use_greyscale = use_greyscale
def preprocess_image(self, image: Image.Image) -> Tuple[Image.Image, dict]:
return image, {}
def convert_image_to_array(self, image: Image.Image) -> np.ndarray:
if isinstance(image, np.ndarray):
img = image
else:
if self.use_greyscale:
image = image.convert("L")
img = np.asarray(image)
return img
@staticmethod
def _get_bg_color(
image: np.ndarray, is_greyscale: bool, invert: bool = False
) -> Union[int, Tuple[int, int, int]]:
# Note: Modified to expect numpy array for bincount
if invert:
image = 255 - image # Simple inversion for greyscale numpy array
if is_greyscale:
bg_color = int(np.bincount(image.flatten()).argmax())
else:
# This part would need more complex logic for color numpy arrays
# For this pipeline, we only use greyscale, so it's fine.
# A simple alternative:
from scipy import stats
bg_color = tuple(stats.mode(image.reshape(-1, 3), axis=0)[0][0])
return bg_color
@staticmethod
def _get_image_contrast(image: np.ndarray) -> Tuple[float, float]:
contrast = np.std(image)
mean_intensity = np.mean(image)
return contrast, mean_intensity
class BilateralFilter(ImagePreprocessor):
"""Applies bilateral filtering."""
def __init__(
self, diameter: int = 9, sigma_color: int = 75, sigma_space: int = 75
) -> None:
super().__init__(use_greyscale=True)
self.diameter = diameter
self.sigma_color = sigma_color
self.sigma_space = sigma_space
def preprocess_image(self, image: np.ndarray) -> Tuple[np.ndarray, dict]:
# Modified to accept and return numpy array for consistency in the pipeline
filtered_image = cv2.bilateralFilter(
image, self.diameter, self.sigma_color, self.sigma_space
)
metadata = {
"diameter": self.diameter,
"sigma_color": self.sigma_color,
"sigma_space": self.sigma_space,
}
return filtered_image, metadata
class SegmentedAdaptiveThreshold(ImagePreprocessor):
"""Applies adaptive thresholding."""
def __init__(
self,
block_size: int = 21,
contrast_threshold: int = 40,
c_low_contrast: int = 5,
c_high_contrast: int = 10,
bg_threshold: int = 127,
) -> None:
super().__init__(use_greyscale=True)
self.block_size = (
block_size if block_size % 2 == 1 else block_size + 1
) # Ensure odd
self.c_low_contrast = c_low_contrast
self.c_high_contrast = c_high_contrast
self.bg_threshold = bg_threshold
self.contrast_threshold = contrast_threshold
def preprocess_image(self, image: np.ndarray) -> Tuple[np.ndarray, dict]:
# Modified to accept and return numpy array
background_color = self._get_bg_color(image, True)
contrast, _ = self._get_image_contrast(image)
c = (
self.c_low_contrast
if contrast <= self.contrast_threshold
else self.c_high_contrast
)
if background_color < self.bg_threshold: # Dark background, light text
adaptive_threshold_image = cv2.adaptiveThreshold(
image,
255,
cv2.ADAPTIVE_THRESH_GAUSSIAN_C,
cv2.THRESH_BINARY_INV,
self.block_size,
-c,
)
else: # Light background, dark text
adaptive_threshold_image = cv2.adaptiveThreshold(
image,
255,
cv2.ADAPTIVE_THRESH_GAUSSIAN_C,
cv2.THRESH_BINARY,
self.block_size,
c,
)
metadata = {"C": c, "background_color": background_color, "contrast": contrast}
return adaptive_threshold_image, metadata
class ImageRescaling(ImagePreprocessor):
"""Rescales images based on their size."""
def __init__(self, target_dpi: int = 300, assumed_input_dpi: int = 96) -> None:
super().__init__(use_greyscale=True)
self.target_dpi = target_dpi
self.assumed_input_dpi = assumed_input_dpi
def preprocess_image(self, image: np.ndarray) -> Tuple[np.ndarray, dict]:
# Modified to accept and return numpy array
scale_factor = self.target_dpi / self.assumed_input_dpi
metadata = {"scale_factor": 1.0}
if scale_factor != 1.0:
width = int(image.shape[1] * scale_factor)
height = int(image.shape[0] * scale_factor)
dimensions = (width, height)
# Use better interpolation for upscaling vs downscaling
interpolation = cv2.INTER_CUBIC if scale_factor > 1.0 else cv2.INTER_AREA
rescaled_image = cv2.resize(image, dimensions, interpolation=interpolation)
metadata["scale_factor"] = scale_factor
return rescaled_image, metadata
return image, metadata
class ContrastSegmentedImageEnhancer(ImagePreprocessor):
"""Class containing all logic to perform contrastive segmentation."""
def __init__(
self,
bilateral_filter: Optional[BilateralFilter] = None,
adaptive_threshold: Optional[SegmentedAdaptiveThreshold] = None,
image_rescaling: Optional[ImageRescaling] = None,
low_contrast_threshold: int = 40,
) -> None:
super().__init__(use_greyscale=True)
self.bilateral_filter = bilateral_filter or BilateralFilter()
self.adaptive_threshold = adaptive_threshold or SegmentedAdaptiveThreshold()
self.image_rescaling = image_rescaling or ImageRescaling()
self.low_contrast_threshold = low_contrast_threshold
def _improve_contrast(self, image: np.ndarray) -> Tuple[np.ndarray, str, str]:
contrast, mean_intensity = self._get_image_contrast(image)
if contrast <= self.low_contrast_threshold:
# Using CLAHE as a generally more robust alternative
clahe = cv2.createCLAHE(clipLimit=2.0, tileGridSize=(8, 8))
adjusted_image = clahe.apply(image)
adjusted_contrast, _ = self._get_image_contrast(adjusted_image)
else:
adjusted_image = image
adjusted_contrast = contrast
return adjusted_image, contrast, adjusted_contrast
def _deskew(self, image_np: np.ndarray) -> np.ndarray:
"""
Corrects the skew of an image.
This method works best on a grayscaled image.
"""
# We'll work with a copy for angle detection
gray = (
cv2.cvtColor(image_np, cv2.COLOR_BGR2GRAY)
if len(image_np.shape) == 3
else image_np.copy()
)
# Invert the image for contour finding
thresh = cv2.threshold(gray, 0, 255, cv2.THRESH_BINARY_INV + cv2.THRESH_OTSU)[1]
coords = np.column_stack(np.where(thresh > 0))
angle = cv2.minAreaRect(coords)[-1]
# Adjust the angle for rotation
if angle < -45:
angle = -(90 + angle)
else:
angle = -angle
# Don't rotate if the angle is negligible
if abs(angle) < 0.1:
return image_np
(h, w) = image_np.shape[:2]
center = (w // 2, h // 2)
M = cv2.getRotationMatrix2D(center, angle, 1.0)
# Use the original numpy image for the rotation to preserve quality
rotated = cv2.warpAffine(
image_np, M, (w, h), flags=cv2.INTER_CUBIC, borderMode=cv2.BORDER_REPLICATE
)
return rotated
def preprocess_image(
self,
image: Image.Image,
perform_deskew: bool = False,
perform_binarization: bool = False,
) -> Tuple[Image.Image, dict]:
"""
A pipeline for OCR preprocessing.
Order: Deskew -> Greyscale -> Rescale -> Denoise -> Enhance Contrast -> Binarize
"""
# 1. Convert PIL image to NumPy array for OpenCV processing
# Assuming the original image is RGB
image_np = np.array(image.convert("RGB"))
# OpenCV uses BGR, so we convert RGB to BGR
image_np_bgr = cv2.cvtColor(image_np, cv2.COLOR_RGB2BGR)
# --- REVISED PIPELINE ---
# 2. Deskew the image (critical new step)
# This is best done early on the full-quality image.
if perform_deskew:
deskewed_image_np = self._deskew(image_np_bgr)
else:
deskewed_image_np = image_np_bgr
# 3. Convert to greyscale
# Your convert_image_to_array probably does this, but for clarity:
gray_image_np = cv2.cvtColor(deskewed_image_np, cv2.COLOR_BGR2GRAY)
# 4. Rescale image to optimal DPI
# Assuming your image_rescaling object can handle a greyscale numpy array
rescaled_image_np, scale_metadata = self.image_rescaling.preprocess_image(
gray_image_np
)
# 5. Apply filtering for noise reduction
# Suggestion: A Median filter is often very effective for scanned docs
# filtered_image_np = cv2.medianBlur(rescaled_image_np, 3)
# Or using your existing bilateral filter:
filtered_image_np, _ = self.bilateral_filter.preprocess_image(rescaled_image_np)
# 6. Improve contrast
adjusted_image_np, _, _ = self._improve_contrast(filtered_image_np)
# 7. Adaptive Thresholding (Binarization) - Final optional step
if perform_binarization:
final_image_np, threshold_metadata = (
self.adaptive_threshold.preprocess_image(adjusted_image_np)
)
else:
final_image_np = adjusted_image_np
threshold_metadata = {}
# Combine metadata
final_metadata = {**scale_metadata, **threshold_metadata}
# Convert final numpy array back to PIL Image for return
# The final image is greyscale, so it's safe to use 'L' mode
return Image.fromarray(final_image_np).convert("L"), final_metadata
def rescale_ocr_data(ocr_data, scale_factor: float):
# We loop from 0 to the number of detected words.
num_boxes = len(ocr_data["text"])
for i in range(num_boxes):
# We only want to process actual words, not empty boxes Tesseract might find
if int(ocr_data["conf"][i]) > -1: # -1 confidence is for structural elements
# Get coordinates from the processed image using the index 'i'
x_proc = ocr_data["left"][i]
y_proc = ocr_data["top"][i]
w_proc = ocr_data["width"][i]
h_proc = ocr_data["height"][i]
# Apply the inverse transformation (division)
x_orig = int(x_proc / scale_factor)
y_orig = int(y_proc / scale_factor)
w_orig = int(w_proc / scale_factor)
h_orig = int(h_proc / scale_factor)
# --- THE MAPPING STEP ---
# Update the dictionary values in-place using the same index 'i'
ocr_data["left"][i] = x_orig
ocr_data["top"][i] = y_orig
ocr_data["width"][i] = w_orig
ocr_data["height"][i] = h_orig
return ocr_data
def filter_entities_for_language(
entities: List[str], valid_language_entities: List[str], language: str
) -> List[str]:
if not valid_language_entities:
print(f"No valid entities supported for language: {language}")
# raise Warning(f"No valid entities supported for language: {language}")
if not entities:
print(f"No entities provided for language: {language}")
# raise Warning(f"No entities provided for language: {language}")
filtered_entities = [
entity for entity in entities if entity in valid_language_entities
]
if not filtered_entities:
print(f"No relevant entities supported for language: {language}")
# raise Warning(f"No relevant entities supported for language: {language}")
if language != "en":
gr.Info(
f"Using {str(filtered_entities)} entities for local model analysis for language: {language}"
)
return filtered_entities
def _get_tesseract_psm(segmentation_level: str) -> int:
"""
Get the appropriate Tesseract PSM (Page Segmentation Mode) value based on segmentation level.
Args:
segmentation_level: "word" or "line"
Returns:
PSM value for Tesseract configuration
"""
if segmentation_level.lower() == "line":
return 6 # Uniform block of text
elif segmentation_level.lower() == "word":
return 11 # Sparse text (word-level)
else:
print(
f"Warning: Unknown segmentation level '{segmentation_level}', defaulting to word-level (PSM 11)"
)
return 11
def _prepare_image_for_vlm(image: Image.Image) -> Image.Image:
"""
Prepare image for VLM by ensuring it doesn't exceed maximum size and DPI limits.
Args:
image: PIL Image to prepare
Returns:
PIL Image that has been resized if necessary to meet size and DPI constraints
"""
if image is None:
return image
width, height = image.size
# Get DPI information (if available)
dpi = image.info.get("dpi", (72, 72)) # Default to 72 DPI if not specified
if isinstance(dpi, tuple):
dpi_x, dpi_y = dpi
# Use the maximum DPI value
current_dpi = max(dpi_x, dpi_y)
else:
current_dpi = float(dpi) if dpi else 72.0
# Calculate scale factors needed
size_scale = 1.0
dpi_scale = 1.0
# Check if total pixels exceed maximum
total_pixels = width * height
if total_pixels > VLM_MAX_IMAGE_SIZE:
# Calculate scale factor to reduce total pixels to maximum
# Since area scales with scale^2, we need sqrt of the ratio
size_scale = (VLM_MAX_IMAGE_SIZE / total_pixels) ** 0.5
print(
f"VLM image size check: Image has {total_pixels:,} pixels ({width}x{height}), exceeds maximum {VLM_MAX_IMAGE_SIZE:,} pixels. Will resize by factor {size_scale:.3f}"
)
# Check if DPI exceeds maximum
if current_dpi > VLM_MAX_DPI:
dpi_scale = VLM_MAX_DPI / current_dpi
# print(
# f"VLM DPI check: Image DPI {current_dpi:.1f} exceeds maximum {VLM_MAX_DPI:.1f} DPI. Will resize by factor {dpi_scale:.3f}"
# )
# Use the smaller scale factor to ensure both constraints are met
final_scale = min(size_scale, dpi_scale)
# Resize if necessary
if final_scale < 1.0:
new_width = int(width * final_scale)
new_height = int(height * final_scale)
# print(
# f"VLM image preparation: Resizing image from {width}x{height} to {new_width}x{new_height} (scale: {final_scale:.3f})"
# )
# Use high-quality resampling for downscaling
image = image.resize((new_width, new_height), Image.Resampling.LANCZOS)
# Update DPI info if it was set
if "dpi" in image.info:
new_dpi = (current_dpi * final_scale, current_dpi * final_scale)
# Create a copy with updated DPI info
image_info = image.info.copy()
image_info["dpi"] = new_dpi
# Note: PIL doesn't allow direct modification of info dict, so we'll just note it
# print(
# f"VLM image preparation: Effective DPI after resize: {new_dpi[0]:.1f}"
# )
else:
total_pixels = width * height
# print(
# f"VLM image preparation: Image size {width}x{height} ({total_pixels:,} pixels) and DPI {current_dpi:.1f} are within limits (max pixels: {VLM_MAX_IMAGE_SIZE:,}, max DPI: {VLM_MAX_DPI})"
# )
return image
def _vlm_ocr_predict(
image: Image.Image,
prompt: str = "Extract the text content from this image.",
) -> Dict[str, Any]:
"""
VLM OCR prediction function that mimics PaddleOCR's interface.
Args:
image: PIL Image to process
prompt: Text prompt for the VLM
Returns:
Dictionary in PaddleOCR format with 'rec_texts' and 'rec_scores'
"""
try:
# Validate image exists and is not None
if image is None:
print("VLM OCR error: Image is None")
return {"rec_texts": [], "rec_scores": []}
# Validate image has valid size (at least 10x10 pixels)
try:
width, height = image.size
if width < 10 or height < 10:
print(
f"VLM OCR error: Image is too small ({width}x{height} pixels). Minimum size is 10x10."
)
return {"rec_texts": [], "rec_scores": []}
except Exception as size_error:
print(f"VLM OCR error: Could not get image size: {size_error}")
return {"rec_texts": [], "rec_scores": []}
# Ensure image is in RGB mode (convert if needed)
try:
if image.mode != "RGB":
# print(f"VLM OCR: Converting image from {image.mode} to RGB mode")
image = image.convert("RGB")
# Update width/height after conversion (should be same, but ensure consistency)
width, height = image.size
except Exception as convert_error:
print(f"VLM OCR error: Could not convert image to RGB: {convert_error}")
return {"rec_texts": [], "rec_scores": []}
# Check and resize image if it exceeds maximum size or DPI limits
try:
image = _prepare_image_for_vlm(image)
width, height = image.size
except Exception as prep_error:
print(f"VLM OCR error: Could not prepare image for VLM: {prep_error}")
return {"rec_texts": [], "rec_scores": []}
# Use the VLM to extract text
# Pass None for parameters to prioritize model-specific defaults from run_vlm.py
# If model defaults are not available, general defaults will be used (matching current values)
# print(f"Calling extract_text_from_image_vlm with image size: {width}x{height}")
extracted_text = extract_text_from_image_vlm(
text=prompt,
image=image,
max_new_tokens=None, # Use model default if available, otherwise MAX_NEW_TOKENS from config
temperature=None, # Use model default if available, otherwise 0.7
top_p=None, # Use model default if available, otherwise 0.9
top_k=None, # Use model default if available, otherwise 50
repetition_penalty=None, # Use model default if available, otherwise 1.3
)
# print(f"VLM OCR extracted text type: {type(extracted_text)}, value: {extracted_text}")
# Check if extracted_text is None or empty
if extracted_text is None:
# print("VLM OCR warning: extract_text_from_image_vlm returned None")
return {"rec_texts": [], "rec_scores": []}
if not isinstance(extracted_text, str):
# print(f"VLM OCR warning: extract_text_from_image_vlm returned unexpected type: {type(extracted_text)}")
return {"rec_texts": [], "rec_scores": []}
if extracted_text.strip():
# Clean the text
cleaned_text = re.sub(r"[\r\n]+", " ", extracted_text)
cleaned_text = cleaned_text.strip()
# Split into words for compatibility with PaddleOCR format
words = cleaned_text.split()
# If text has more than 30 words, assume something went wrong and skip it
if len(words) > 30:
print(
f"VLM OCR warning: Extracted text has {len(words)} words, which exceeds the 30 word limit. Skipping."
)
return {"rec_texts": [], "rec_scores": []}
# Create PaddleOCR-compatible result
result = {
"rec_texts": words,
"rec_scores": [0.95] * len(words), # High confidence for VLM results
}
return result
else:
# print("VLM OCR warning: Extracted text is empty after stripping")
return {"rec_texts": [], "rec_scores": []}
except Exception:
# print(f"VLM OCR error: {e}")
# print(f"VLM OCR error traceback: {traceback.format_exc()}")
return {"rec_texts": [], "rec_scores": []}
class CustomImageAnalyzerEngine:
def __init__(
self,
analyzer_engine: Optional[AnalyzerEngine] = None,
ocr_engine: str = "tesseract",
tesseract_config: Optional[str] = None,
paddle_kwargs: Optional[Dict[str, Any]] = None,
image_preprocessor: Optional[ImagePreprocessor] = None,
language: Optional[str] = DEFAULT_LANGUAGE,
output_folder: str = OUTPUT_FOLDER,
):
"""
Initializes the CustomImageAnalyzerEngine.
:param ocr_engine: The OCR engine to use ("tesseract", "hybrid-paddle", "hybrid-vlm", "hybrid-paddle-vlm", or "paddle").
:param analyzer_engine: The Presidio AnalyzerEngine instance.
:param tesseract_config: Configuration string for Tesseract. If None, uses TESSERACT_SEGMENTATION_LEVEL config.
:param paddle_kwargs: Dictionary of keyword arguments for PaddleOCR constructor.
:param image_preprocessor: Optional image preprocessor.
:param language: Preferred OCR language (e.g., "en", "fr", "de"). Defaults to DEFAULT_LANGUAGE.
:param output_folder: The folder to save the output images to.
"""
if ocr_engine not in LOCAL_OCR_MODEL_OPTIONS:
raise ValueError(
f"ocr_engine must be one of the following: {LOCAL_OCR_MODEL_OPTIONS}"
)
self.ocr_engine = ocr_engine
# Language setup
self.language = language or DEFAULT_LANGUAGE or "en"
self.tesseract_lang = _tesseract_lang_code(self.language)
self.paddle_lang = _paddle_lang_code(self.language)
# Security: Validate and normalize output_folder at construction time
# This ensures the object is always in a secure state and prevents
# any future code from accidentally using an untrusted directory
normalized_output_folder = os.path.normpath(os.path.abspath(output_folder))
if not validate_folder_containment(normalized_output_folder, OUTPUT_FOLDER):
raise ValueError(
f"Unsafe output folder path: {output_folder}. Must be contained within {OUTPUT_FOLDER}"
)
self.output_folder = normalized_output_folder
if (
self.ocr_engine == "paddle"
or self.ocr_engine == "hybrid-paddle"
or self.ocr_engine == "hybrid-paddle-vlm"
):
if PaddleOCR is None:
raise ImportError(
"PaddleOCR is not installed. Please run 'pip install paddleocr paddlepaddle' in your python environment and retry."
)
# Set PaddleOCR model directory environment variable (only if specified).
if PADDLE_MODEL_PATH and PADDLE_MODEL_PATH.strip():
os.environ["PADDLEOCR_MODEL_DIR"] = PADDLE_MODEL_PATH
print(f"Setting PaddleOCR model path to: {PADDLE_MODEL_PATH}")
else:
print("Using default PaddleOCR model storage location")
# Default paddle configuration if none provided
if paddle_kwargs is None:
paddle_kwargs = {
"det_db_unclip_ratio": PADDLE_DET_DB_UNCLIP_RATIO,
"use_textline_orientation": PADDLE_USE_TEXTLINE_ORIENTATION,
"use_doc_orientation_classify": False,
"use_doc_unwarping": False,
"lang": self.paddle_lang,
}
else:
# Enforce language if not explicitly provided
paddle_kwargs.setdefault("lang", self.paddle_lang)
self.paddle_ocr = PaddleOCR(**paddle_kwargs)
elif self.ocr_engine == "hybrid-vlm":
# VLM-based hybrid OCR - no additional initialization needed
# The VLM model is loaded when run_vlm.py is imported
print(f"Initializing hybrid VLM OCR with model: {SELECTED_MODEL}")
self.paddle_ocr = None # Not using PaddleOCR
if self.ocr_engine == "hybrid-paddle-vlm":
# Hybrid PaddleOCR + VLM - requires both PaddleOCR and VLM
# The VLM model is loaded when run_vlm.py is imported
print(
f"Initializing hybrid PaddleOCR + VLM OCR with model: {SELECTED_MODEL}"
)
if not analyzer_engine:
analyzer_engine = AnalyzerEngine()
self.analyzer_engine = analyzer_engine
# Set Tesseract configuration based on segmentation level
if tesseract_config:
self.tesseract_config = tesseract_config
else:
# Following function does not actually work correctly, so always use PSM 11
psm_value = TESSERACT_SEGMENTATION_LEVEL # _get_tesseract_psm(TESSERACT_SEGMENTATION_LEVEL)
self.tesseract_config = f"--oem 3 --psm {psm_value}"
# print(
# f"Tesseract configured for {TESSERACT_SEGMENTATION_LEVEL}-level segmentation (PSM {psm_value})"
# )
if not image_preprocessor:
image_preprocessor = ContrastSegmentedImageEnhancer()
self.image_preprocessor = image_preprocessor
def _sanitize_filename(
self, text: str, max_length: int = 20, fallback_prefix: str = "unknown_text"
) -> str:
"""
Sanitizes text for use in filenames by removing invalid characters and limiting length.
:param text: The text to sanitize
:param max_length: Maximum length of the sanitized text
:param fallback_prefix: Prefix to use if sanitization fails
:return: Sanitized text safe for filenames
"""
# Remove or replace invalid filename characters
# Windows: < > : " | ? * \ /
# Unix: / (forward slash)
sanitized = safe_sanitize_text(text)
# Remove leading/trailing underscores and spaces
sanitized = sanitized.strip("_ ")
# If empty after sanitization, use a default value
if not sanitized:
sanitized = fallback_prefix
# Limit to max_length characters
if len(sanitized) > max_length:
sanitized = sanitized[:max_length]
# Ensure we don't end with an underscore if we cut in the middle
sanitized = sanitized.rstrip("_")
# Final check: if still empty or too short, use fallback
if not sanitized or len(sanitized) < 3:
sanitized = fallback_prefix
return sanitized
def _create_safe_filename_with_confidence(
self,
original_text: str,
new_text: str,
conf: int,
new_conf: int,
ocr_type: str = "OCR",
) -> str:
"""
Creates a safe filename using confidence values when text sanitization fails.
Args:
original_text: Original text from Tesseract
new_text: New text from VLM/PaddleOCR
conf: Original confidence score
new_conf: New confidence score
ocr_type: Type of OCR used (VLM, Paddle, etc.)
Returns:
Safe filename string
"""
# Try to sanitize both texts
safe_original = self._sanitize_filename(
original_text, max_length=15, fallback_prefix=f"orig_conf_{conf}"
)
safe_new = self._sanitize_filename(
new_text, max_length=15, fallback_prefix=f"new_conf_{new_conf}"
)
# If both sanitizations resulted in fallback names, create a confidence-based name
if safe_original.startswith("unknown_text") and safe_new.startswith(
"unknown_text"
):
return f"{ocr_type}_conf_{conf}_to_conf_{new_conf}"
return f"{safe_original}_conf_{conf}_to_{safe_new}_conf_{new_conf}"
def _is_line_level_data(self, ocr_data: Dict[str, List]) -> bool:
"""
Determines if OCR data contains line-level results (multiple words per bounding box).
Args:
ocr_data: Dictionary with OCR data
Returns:
True if data appears to be line-level, False otherwise
"""
if not ocr_data or not ocr_data.get("text"):
return False
# Check if any text entries contain multiple words
for text in ocr_data["text"]:
if text.strip() and len(text.split()) > 1:
return True
return False
def _convert_paddle_to_tesseract_format(
self,
paddle_results: List[Any],
input_image_width: int = None,
input_image_height: int = None,
image_name: str = None,
image: Image.Image = None,
) -> Dict[str, List]:
"""Converts PaddleOCR result format to Tesseract's dictionary format using relative coordinates.
This function uses a safer approach: converts PaddleOCR coordinates to relative (0-1) coordinates
based on whatever coordinate space PaddleOCR uses, then scales them to the input image dimensions.
This avoids issues with PaddleOCR's internal image resizing.
Args:
paddle_results: List of PaddleOCR result dictionaries
input_image_width: Width of the input image passed to PaddleOCR (target dimensions for scaling)
input_image_height: Height of the input image passed to PaddleOCR (target dimensions for scaling)
image_name: Name of the image
image: Image object
"""
output = {
"text": list(),
"left": list(),
"top": list(),
"width": list(),
"height": list(),
"conf": list(),
"model": list(),
}
# paddle_results is now a list of dictionaries with detailed information
if not paddle_results:
return output
# Validate that we have target dimensions
if input_image_width is None or input_image_height is None:
print(
"Warning: Input image dimensions not provided. PaddleOCR coordinates may be incorrectly scaled."
)
# Fallback: we'll try to detect from coordinates, but this is less reliable
use_relative_coords = False
else:
use_relative_coords = True
for page_result in paddle_results:
# Extract text recognition results from the new format
rec_texts = page_result.get("rec_texts", list())
rec_scores = page_result.get("rec_scores", list())
rec_polys = page_result.get("rec_polys", list())
rec_models = page_result.get("rec_models", list())
# PaddleOCR may return image dimensions in the result - check for them
# Some versions of PaddleOCR include this information
result_image_width = page_result.get("image_width")
result_image_height = page_result.get("image_height")
# PaddleOCR typically returns coordinates in the input image space
# However, it may internally resize images, so we need to check if coordinates
# are in a different space by comparing with explicit metadata or detecting from coordinates
# First pass: determine PaddleOCR's coordinate space by finding max coordinates
# This tells us what coordinate space PaddleOCR is actually using
max_x_coord = 0
max_y_coord = 0
for bounding_box in rec_polys:
if hasattr(bounding_box, "tolist"):
box = bounding_box.tolist()
else:
box = bounding_box
if box and len(box) > 0:
x_coords = [p[0] for p in box]
y_coords = [p[1] for p in box]
max_x_coord = max(max_x_coord, max(x_coords) if x_coords else 0)
max_y_coord = max(max_y_coord, max(y_coords) if y_coords else 0)
# Determine PaddleOCR's coordinate space dimensions
# Priority: explicit result metadata > input dimensions (standard PaddleOCR behavior)
# Note: PaddleOCR typically returns coordinates in the input image space.
# We only use a different coordinate space if PaddleOCR provides explicit metadata.
# Using max coordinates to detect coordinate space is unreliable because:
# 1. Text might not extend to image edges
# 2. There might be padding
# 3. Max coordinates don't necessarily equal image dimensions
if result_image_width is not None and result_image_height is not None:
# Use explicit metadata from PaddleOCR if available (most reliable)
paddle_coord_width = result_image_width
paddle_coord_height = result_image_height
# Only use relative conversion if coordinate space differs from input
if (
paddle_coord_width != input_image_width
or paddle_coord_height != input_image_height
):
print(
f"PaddleOCR metadata indicates coordinate space ({paddle_coord_width}x{paddle_coord_height}) "
f"differs from input ({input_image_width}x{input_image_height}). "
f"Using metadata for coordinate conversion."
)
elif input_image_width is not None and input_image_height is not None:
# Default: assume coordinates are in input image space (standard PaddleOCR behavior)
# This is the most common case and avoids incorrect scaling
paddle_coord_width = input_image_width
paddle_coord_height = input_image_height
else:
# Fallback: use max coordinates if we have no other information
paddle_coord_width = max_x_coord if max_x_coord > 0 else 1
paddle_coord_height = max_y_coord if max_y_coord > 0 else 1
use_relative_coords = False
print(
f"Warning: No input dimensions provided. Using detected coordinate space ({paddle_coord_width}x{paddle_coord_height}) from max coordinates."
)
# Validate coordinate space dimensions
if paddle_coord_width is None or paddle_coord_height is None:
paddle_coord_width = input_image_width or 1
paddle_coord_height = input_image_height or 1
use_relative_coords = False
if paddle_coord_width <= 0 or paddle_coord_height <= 0:
print(
f"Warning: Invalid PaddleOCR coordinate space dimensions ({paddle_coord_width}x{paddle_coord_height}). Using input dimensions."
)
paddle_coord_width = input_image_width or 1
paddle_coord_height = input_image_height or 1
use_relative_coords = False
# If coordinate space matches input dimensions, coordinates are already in the correct space
# Only use relative coordinate conversion if coordinate space differs from input
if (
paddle_coord_width == input_image_width
and paddle_coord_height == input_image_height
and input_image_width is not None
and input_image_height is not None
):
# Coordinates are already in input space, no conversion needed
use_relative_coords = False
print(
f"PaddleOCR coordinates are in input image space ({input_image_width}x{input_image_height}). "
f"Using coordinates directly without conversion."
)
# Second pass: convert coordinates using relative coordinate approach
# Use default "Paddle" if rec_models is not available or doesn't match length
if len(rec_models) != len(rec_texts):
print(
f"Warning: rec_models length ({len(rec_models)}) doesn't match rec_texts length ({len(rec_texts)}). Using default 'Paddle' for all."
)
rec_models = ["Paddle"] * len(rec_texts)
# Update page_result to keep it consistent
page_result["rec_models"] = rec_models
else:
# Ensure we're using the rec_models from page_result (which may have been modified)
rec_models = page_result.get("rec_models", rec_models)
# Debug: Print model distribution
vlm_count = sum(1 for m in rec_models if m == "VLM")
if vlm_count > 0:
print(
f"Found {vlm_count} VLM-labeled lines out of {len(rec_models)} total lines in page_result"
)
for line_text, line_confidence, bounding_box, line_model in zip(
rec_texts, rec_scores, rec_polys, rec_models
):
# bounding_box is now a numpy array with shape (4, 2)
# Convert to list of coordinates if it's a numpy array
if hasattr(bounding_box, "tolist"):
box = bounding_box.tolist()
else:
box = bounding_box
if not box or len(box) == 0:
continue
# box is [[x1,y1], [x2,y2], [x3,y3], [x4,y4]]
x_coords = [p[0] for p in box]
y_coords = [p[1] for p in box]
# Extract bounding box coordinates in PaddleOCR's coordinate space
line_left_paddle = float(min(x_coords))
line_top_paddle = float(min(y_coords))
line_right_paddle = float(max(x_coords))
line_bottom_paddle = float(max(y_coords))
line_width_paddle = line_right_paddle - line_left_paddle
line_height_paddle = line_bottom_paddle - line_top_paddle
# Convert to relative coordinates (0-1) based on PaddleOCR's coordinate space
# Then scale to input image dimensions
if (
use_relative_coords
and paddle_coord_width > 0
and paddle_coord_height > 0
):
# Normalize to relative coordinates [0-1]
rel_left = line_left_paddle / paddle_coord_width
rel_top = line_top_paddle / paddle_coord_height
rel_width = line_width_paddle / paddle_coord_width
rel_height = line_height_paddle / paddle_coord_height
# Scale to input image dimensions
line_left = rel_left * input_image_width
line_top = rel_top * input_image_height
line_width = rel_width * input_image_width
line_height = rel_height * input_image_height
else:
# Fallback: use coordinates directly (may cause issues if coordinate spaces don't match)
line_left = line_left_paddle
line_top = line_top_paddle
line_width = line_width_paddle
line_height = line_height_paddle
# if input_image_width and input_image_height:
# print(f"Warning: Using PaddleOCR coordinates directly. This may cause scaling issues.")
# Ensure coordinates are within valid bounds
if input_image_width and input_image_height:
line_left = max(0, min(line_left, input_image_width))
line_top = max(0, min(line_top, input_image_height))
line_width = max(0, min(line_width, input_image_width - line_left))
line_height = max(
0, min(line_height, input_image_height - line_top)
)
# Add line-level data
output["text"].append(line_text)
output["left"].append(round(line_left, 2))
output["top"].append(round(line_top, 2))
output["width"].append(round(line_width, 2))
output["height"].append(round(line_height, 2))
output["conf"].append(int(line_confidence * 100))
output["model"].append(line_model if line_model else "Paddle")
return output
def _convert_line_to_word_level(
self,
line_data: Dict[str, List],
image_width: int,
image_height: int,
image: Image.Image,
image_name: str = None,
) -> Dict[str, List]:
"""
Converts line-level OCR results to word-level using AdaptiveSegmenter.segment().
This method processes each line individually using the adaptive segmentation algorithm.
Args:
line_data: Dictionary with keys "text", "left", "top", "width", "height", "conf" (all lists)
image_width: Width of the full image
image_height: Height of the full image
image: PIL Image object of the full image
image_name: Name of the image
Returns:
Dictionary with same keys as input, containing word-level bounding boxes
"""
output = {
"text": list(),
"left": list(),
"top": list(),
"width": list(),
"height": list(),
"conf": list(),
"model": list(),
}
if not line_data or not line_data.get("text"):
return output
# Convert PIL Image to numpy array (BGR format for OpenCV)
if hasattr(image, "size"): # PIL Image
image_np = np.array(image)
if len(image_np.shape) == 3:
# Convert RGB to BGR for OpenCV
image_np = cv2.cvtColor(image_np, cv2.COLOR_RGB2BGR)
elif len(image_np.shape) == 2:
# Grayscale - convert to BGR
image_np = cv2.cvtColor(image_np, cv2.COLOR_GRAY2BGR)
else:
# Already numpy array
image_np = image.copy()
if len(image_np.shape) == 2:
image_np = cv2.cvtColor(image_np, cv2.COLOR_GRAY2BGR)
# Validate that image_np dimensions match the expected image_width and image_height
# PIL Image.size returns (width, height), but numpy array shape is (height, width, channels)
actual_height, actual_width = image_np.shape[:2]
if actual_width != image_width or actual_height != image_height:
print(
f"Warning: Image dimension mismatch! Expected {image_width}x{image_height}, but got {actual_width}x{actual_height}"
)
# print(f"Using actual dimensions: {actual_width}x{actual_height}")
# Update to use actual dimensions
image_width = actual_width
image_height = actual_height
print("segmenting line-level OCR results to word-level...")
segmenter = AdaptiveSegmenter(output_folder=self.output_folder)
# Process each line
for i in range(len(line_data["text"])):
line_text = line_data["text"][i]
line_conf = line_data["conf"][i]
# Extract model, defaulting to "Paddle" if not available
if "model" in line_data and len(line_data["model"]) > i:
line_model = line_data["model"][i]
else:
line_model = "Paddle"
# Get the float values
f_left = float(line_data["left"][i])
f_top = float(line_data["top"][i])
f_width = float(line_data["width"][i])
f_height = float(line_data["height"][i])
# A simple heuristic to check if coords are normalized
# If any value is > 1.0, assume they are already pixels
is_normalized = (
f_left <= 1.0 and f_top <= 1.0 and f_width <= 1.0 and f_height <= 1.0
)
if is_normalized:
# Convert from normalized (0.0-1.0) to absolute pixels
line_left = float(round(f_left * image_width))
line_top = float(round(f_top * image_height))
line_width = float(round(f_width * image_width))
line_height = float(round(f_height * image_height))
else:
# They are already pixels, just convert to int
line_left = float(round(f_left))
line_top = float(round(f_top))
line_width = float(round(f_width))
line_height = float(round(f_height))
if not line_text.strip():
continue
# Clamp bounding box to image boundaries
line_left = int(max(0, min(line_left, image_width - 1)))
line_top = int(max(0, min(line_top, image_height - 1)))
line_width = int(max(1, min(line_width, image_width - line_left)))
line_height = int(max(1, min(line_height, image_height - line_top)))
# Validate crop coordinates are within bounds
if line_left >= image_width or line_top >= image_height:
# print(f"Warning: Line coordinates out of bounds. Skipping line '{line_text[:50]}...'")
continue
if line_left + line_width > image_width:
line_width = image_width - line_left
# print(f"Warning: Adjusted line_width to {line_width} to fit within image")
if line_top + line_height > image_height:
line_height = image_height - line_top
# print(f"Warning: Adjusted line_height to {line_height} to fit within image")
# Ensure we have valid dimensions
if line_width <= 0 or line_height <= 0:
# print(f"Warning: Invalid line dimensions ({line_width}x{line_height}). Skipping line '{line_text[:50]}...'")
continue
# Crop the line image from the full image
try:
line_image = image_np[
line_top : line_top + line_height,
line_left : line_left + line_width,
]
except IndexError:
# print(f"Error cropping line image: {e}")
# print(f"Attempted to crop: [{line_top}:{line_top + line_height}, {line_left}:{line_left + line_width}]")
# print(f"Image_np shape: {image_np.shape}")
continue
if line_image is None or line_image.size == 0:
# print(f"Warning: Cropped line_image is None or empty. Skipping line '{line_text[:50]}...'")
continue
# Validate line_image has valid shape
if len(line_image.shape) < 2:
# print(f"Warning: line_image has invalid shape {line_image.shape}. Skipping line '{line_text[:50]}...'")
continue
# Create single-line data structure for segment method
single_line_data = {
"text": [line_text],
"left": [0], # Relative to cropped image
"top": [0],
"width": [line_width],
"height": [line_height],
"conf": [line_conf],
}
# Validate line_image before passing to segmenter
if line_image is None:
# print(f"Error: line_image is None for line '{line_text[:50]}...'")
continue
# Use AdaptiveSegmenter.segment() to segment this line
try:
word_output, _ = segmenter.segment(
single_line_data, line_image, image_name=image_name
)
except Exception:
# print(f"Error in segmenter.segment for line '{line_text[:50]}...': {e}")
# print(f"line_image shape: {line_image.shape if line_image is not None else 'None'}")
raise
if not word_output or not word_output.get("text"):
# If segmentation failed, fall back to proportional estimation
words = line_text.split()
if words:
num_chars = len("".join(words))
num_spaces = len(words) - 1
if num_chars > 0:
char_space_ratio = 2.0
estimated_space_width = (
line_width / (num_chars * char_space_ratio + num_spaces)
if (num_chars * char_space_ratio + num_spaces) > 0
else line_width / num_chars
)
avg_char_width = estimated_space_width * char_space_ratio
current_left = 0
for word in words:
word_width = len(word) * avg_char_width
clamped_left = max(0, min(current_left, line_width))
clamped_width = max(
0, min(word_width, line_width - clamped_left)
)
output["text"].append(word)
output["left"].append(
line_left + clamped_left
) # Add line offset
output["top"].append(line_top)
output["width"].append(clamped_width)
output["height"].append(line_height)
output["conf"].append(line_conf)
output["model"].append(line_model)
current_left += word_width + estimated_space_width
continue
# Adjust coordinates back to full image coordinates
for j in range(len(word_output["text"])):
output["text"].append(word_output["text"][j])
output["left"].append(line_left + word_output["left"][j])
output["top"].append(line_top + word_output["top"][j])
output["width"].append(word_output["width"][j])
output["height"].append(word_output["height"][j])
output["conf"].append(word_output["conf"][j])
# Preserve the model from the line-level data
output["model"].append(line_model)
return output
def _visualize_tesseract_bounding_boxes(
self,
image: Image.Image,
ocr_data: Dict[str, List],
image_name: str = None,
visualisation_folder: str = "tesseract_visualisations",
) -> None:
"""
Visualizes Tesseract OCR bounding boxes with confidence-based colors and a legend.
Args:
image: The PIL Image object
ocr_data: Tesseract OCR data dictionary
image_name: Optional name for the saved image file
"""
if not ocr_data or not ocr_data.get("text"):
return
# Convert PIL image to OpenCV format
image_cv = cv2.cvtColor(np.array(image), cv2.COLOR_RGB2BGR)
# Get image dimensions
height, width = image_cv.shape[:2]
# Define confidence ranges and colors
confidence_ranges = [
(80, 100, (0, 255, 0), "High (80-100%)"), # Green
(50, 79, (0, 165, 255), "Medium (50-79%)"), # Orange
(0, 49, (0, 0, 255), "Low (0-49%)"), # Red
]
# Process each detected text element
for i in range(len(ocr_data["text"])):
text = ocr_data["text"][i]
conf = int(ocr_data["conf"][i])
# Skip empty text or invalid confidence
if not text.strip() or conf == -1:
continue
left = ocr_data["left"][i]
top = ocr_data["top"][i]
width_box = ocr_data["width"][i]
height_box = ocr_data["height"][i]
# Calculate bounding box coordinates
x1 = int(left)
y1 = int(top)
x2 = int(left + width_box)
y2 = int(top + height_box)
# Ensure coordinates are within image bounds
x1 = max(0, min(x1, width))
y1 = max(0, min(y1, height))
x2 = max(0, min(x2, width))
y2 = max(0, min(y2, height))
# Skip if bounding box is invalid
if x2 <= x1 or y2 <= y1:
continue
# Determine color based on confidence score
color = (0, 0, 255) # Default to red
for min_conf, max_conf, conf_color, _ in confidence_ranges:
if min_conf <= conf <= max_conf:
color = conf_color
break
# Draw bounding box
cv2.rectangle(image_cv, (x1, y1), (x2, y2), color, 1)
# Add legend
self._add_confidence_legend(image_cv, confidence_ranges)
# Save the visualization
tesseract_viz_folder = os.path.join(self.output_folder, visualisation_folder)
# Double-check the constructed path is safe
if not validate_folder_containment(tesseract_viz_folder, OUTPUT_FOLDER):
raise ValueError(
f"Unsafe tesseract visualisations folder path: {tesseract_viz_folder}"
)
os.makedirs(tesseract_viz_folder, exist_ok=True)
# Generate filename
if image_name:
# Remove file extension if present
base_name = os.path.splitext(image_name)[0]
filename = f"{base_name}_{visualisation_folder}.jpg"
else:
timestamp = int(time.time())
filename = f"{visualisation_folder}_{timestamp}.jpg"
output_path = os.path.join(tesseract_viz_folder, filename)
# Save the image
cv2.imwrite(output_path, image_cv)
print(f"Tesseract visualization saved to: {output_path}")
def _add_confidence_legend(
self, image_cv: np.ndarray, confidence_ranges: List[Tuple]
) -> None:
"""
Adds a confidence legend to the visualization image.
Args:
image_cv: OpenCV image array
confidence_ranges: List of tuples containing (min_conf, max_conf, color, label)
"""
height, width = image_cv.shape[:2]
# Legend parameters
legend_width = 200
legend_height = 100
legend_x = width - legend_width - 20
legend_y = 20
# Draw legend background
cv2.rectangle(
image_cv,
(legend_x, legend_y),
(legend_x + legend_width, legend_y + legend_height),
(255, 255, 255), # White background
-1,
)
cv2.rectangle(
image_cv,
(legend_x, legend_y),
(legend_x + legend_width, legend_y + legend_height),
(0, 0, 0), # Black border
2,
)
# Add title
title_text = "Confidence Levels"
font_scale = 0.6
font_thickness = 2
(title_width, title_height), _ = cv2.getTextSize(
title_text, cv2.FONT_HERSHEY_SIMPLEX, font_scale, font_thickness
)
title_x = legend_x + (legend_width - title_width) // 2
title_y = legend_y + title_height + 10
cv2.putText(
image_cv,
title_text,
(title_x, title_y),
cv2.FONT_HERSHEY_SIMPLEX,
font_scale,
(0, 0, 0), # Black text
font_thickness,
)
# Add confidence range items
item_spacing = 25
start_y = title_y + 25
for i, (min_conf, max_conf, color, label) in enumerate(confidence_ranges):
item_y = start_y + i * item_spacing
# Draw color box
box_size = 15
box_x = legend_x + 10
box_y = item_y - box_size
cv2.rectangle(
image_cv,
(box_x, box_y),
(box_x + box_size, box_y + box_size),
color,
-1,
)
cv2.rectangle(
image_cv,
(box_x, box_y),
(box_x + box_size, box_y + box_size),
(0, 0, 0), # Black border
1,
)
# Add label text
label_x = box_x + box_size + 10
label_y = item_y - 5
cv2.putText(
image_cv,
label,
(label_x, label_y),
cv2.FONT_HERSHEY_SIMPLEX,
0.5,
(0, 0, 0), # Black text
1,
)
# Calculate line-level bounding boxes and average confidence
def _calculate_line_bbox(self, group):
# Get the leftmost and rightmost positions
left = group["left"].min()
top = group["top"].min()
right = (group["left"] + group["width"]).max()
bottom = (group["top"] + group["height"]).max()
# Calculate width and height
width = right - left
height = bottom - top
# Calculate average confidence
avg_conf = round(group["conf"].mean(), 0)
return pd.Series(
{
"text": " ".join(group["text"].astype(str).tolist()),
"left": left,
"top": top,
"width": width,
"height": height,
"conf": avg_conf,
}
)
def _perform_hybrid_ocr(
self,
image: Image.Image,
confidence_threshold: int = HYBRID_OCR_CONFIDENCE_THRESHOLD,
padding: int = HYBRID_OCR_PADDING,
ocr: Optional[Any] = None,
image_name: str = "unknown_image_name",
) -> Dict[str, list]:
"""
Performs hybrid OCR on an image using Tesseract for initial OCR and PaddleOCR/VLM to enhance
results for low-confidence or uncertain words.
Args:
image (Image.Image): The input image (PIL format) to be processed.
confidence_threshold (int, optional): Tesseract confidence threshold below which words are
re-analyzed with secondary OCR (PaddleOCR/VLM). Defaults to HYBRID_OCR_CONFIDENCE_THRESHOLD.
padding (int, optional): Pixel padding (in all directions) to add around each word box when
cropping for secondary OCR. Defaults to HYBRID_OCR_PADDING.
ocr (Optional[Any], optional): An instance of the PaddleOCR or VLM engine. If None, will use the
instance's `paddle_ocr` attribute if available. Only necessary for PaddleOCR-based pipelines.
image_name (str, optional): Optional name of the image, useful for debugging and visualization.
Returns:
Dict[str, list]: OCR results in the dictionary format of pytesseract.image_to_data (keys:
'text', 'left', 'top', 'width', 'height', 'conf', 'model', ...).
"""
# Determine if we're using VLM or PaddleOCR
use_vlm = self.ocr_engine == "hybrid-vlm"
if not use_vlm:
if ocr is None:
if hasattr(self, "paddle_ocr") and self.paddle_ocr is not None:
ocr = self.paddle_ocr
else:
raise ValueError(
"No OCR object provided and 'paddle_ocr' is not initialized."
)
# print("Starting hybrid OCR process...")
# 1. Get initial word-level results from Tesseract
tesseract_data = pytesseract.image_to_data(
image,
output_type=pytesseract.Output.DICT,
config=self.tesseract_config,
lang=self.tesseract_lang,
)
if TESSERACT_WORD_LEVEL_OCR is False:
ocr_df = pd.DataFrame(tesseract_data)
# Filter out invalid entries (confidence == -1)
ocr_df = ocr_df[ocr_df.conf != -1]
# Group by line and aggregate text
line_groups = ocr_df.groupby(["block_num", "par_num", "line_num"])
ocr_data = line_groups.apply(self._calculate_line_bbox).reset_index()
# Overwrite tesseract_data with the aggregated data
tesseract_data = {
"text": ocr_data["text"].tolist(),
"left": ocr_data["left"].astype(int).tolist(),
"top": ocr_data["top"].astype(int).tolist(),
"width": ocr_data["width"].astype(int).tolist(),
"height": ocr_data["height"].astype(int).tolist(),
"conf": ocr_data["conf"].tolist(),
"model": ["Tesseract"] * len(ocr_data), # Add model field
}
final_data = {
"text": list(),
"left": list(),
"top": list(),
"width": list(),
"height": list(),
"conf": list(),
"model": list(), # Track which model was used for each word
}
num_words = len(tesseract_data["text"])
# This handles the "no text on page" case. If num_words is 0, the loop is skipped
# and an empty dictionary with empty lists is returned, which is the correct behavior.
for i in range(num_words):
text = tesseract_data["text"][i]
conf = int(tesseract_data["conf"][i])
# Skip empty text boxes or non-word elements (like page/block markers)
if not text.strip() or conf == -1:
continue
left = tesseract_data["left"][i]
top = tesseract_data["top"][i]
width = tesseract_data["width"][i]
height = tesseract_data["height"][i]
# line_number = tesseract_data['abs_line_id'][i]
# Initialize model as Tesseract (default)
model_used = "Tesseract"
# If confidence is low, use PaddleOCR for a second opinion
if conf < confidence_threshold:
img_width, img_height = image.size
crop_left = max(0, left - padding - 15)
crop_top = max(0, top - padding)
crop_right = min(img_width, left + width + padding + 15)
crop_bottom = min(img_height, top + height + padding)
# Ensure crop dimensions are valid
if crop_right <= crop_left or crop_bottom <= crop_top:
continue # Skip invalid crops
cropped_image = image.crop(
(crop_left, crop_top, crop_right, crop_bottom)
)
if use_vlm:
# Use VLM for OCR
vlm_result = _vlm_ocr_predict(cropped_image)
rec_texts = vlm_result.get("rec_texts", [])
rec_scores = vlm_result.get("rec_scores", [])
else:
# Use PaddleOCR
cropped_image_np = np.array(cropped_image)
if len(cropped_image_np.shape) == 2:
cropped_image_np = np.stack([cropped_image_np] * 3, axis=-1)
paddle_results = ocr.predict(cropped_image_np)
if paddle_results and paddle_results[0]:
rec_texts = paddle_results[0].get("rec_texts", [])
rec_scores = paddle_results[0].get("rec_scores", [])
else:
rec_texts = []
rec_scores = []
if rec_texts and rec_scores:
new_text = " ".join(rec_texts)
new_conf = int(round(np.median(rec_scores) * 100, 0))
# Only replace if Paddle's/VLM's confidence is better
if new_conf > conf:
ocr_type = "VLM" if use_vlm else "Paddle"
print(
f" Re-OCR'd word: '{text}' (conf: {conf}) -> '{new_text}' (conf: {new_conf:.0f}) [{ocr_type}]"
)
# For exporting example image comparisons, not used here
safe_filename = self._create_safe_filename_with_confidence(
text, new_text, conf, new_conf, ocr_type
)
if SAVE_EXAMPLE_HYBRID_IMAGES:
# Normalize and validate image_name to prevent path traversal attacks
normalized_image_name = os.path.normpath(
image_name + "_" + ocr_type
)
# Ensure the image name doesn't contain path traversal characters
if (
".." in normalized_image_name
or "/" in normalized_image_name
or "\\" in normalized_image_name
):
normalized_image_name = (
"safe_image" # Fallback to safe default
)
hybrid_ocr_examples_folder = (
self.output_folder
+ f"/hybrid_ocr_examples/{normalized_image_name}"
)
# Validate the constructed path is safe before creating directories
if not validate_folder_containment(
hybrid_ocr_examples_folder, OUTPUT_FOLDER
):
raise ValueError(
f"Unsafe hybrid_ocr_examples folder path: {hybrid_ocr_examples_folder}"
)
if not os.path.exists(hybrid_ocr_examples_folder):
os.makedirs(hybrid_ocr_examples_folder)
output_image_path = (
hybrid_ocr_examples_folder + f"/{safe_filename}.png"
)
print(f"Saving example image to {output_image_path}")
cropped_image.save(output_image_path)
text = new_text
conf = new_conf
model_used = ocr_type # Update model to VLM or Paddle
else:
ocr_type = "VLM" if use_vlm else "Paddle"
print(
f" '{text}' (conf: {conf}) -> {ocr_type} result '{new_text}' (conf: {new_conf:.0f}) was not better. Keeping original."
)
else:
# OCR ran but found nothing, discard original word
ocr_type = "VLM" if use_vlm else "Paddle"
print(
f" '{text}' (conf: {conf}) -> No text found by {ocr_type}. Discarding."
)
text = ""
# Append the final result (either original, replaced, or skipped if empty)
if text.strip():
final_data["text"].append(clean_unicode_text(text))
final_data["left"].append(left)
final_data["top"].append(top)
final_data["width"].append(width)
final_data["height"].append(height)
final_data["conf"].append(int(conf))
final_data["model"].append(model_used)
# final_data['line_number'].append(int(line_number))
return final_data
def _perform_hybrid_paddle_vlm_ocr(
self,
image: Image.Image,
ocr: Optional[Any] = None,
paddle_results: List[Any] = None,
confidence_threshold: int = HYBRID_OCR_CONFIDENCE_THRESHOLD,
padding: int = HYBRID_OCR_PADDING,
image_name: str = "unknown_image_name",
input_image_width: int = None,
input_image_height: int = None,
) -> List[Any]:
"""
Performs OCR using PaddleOCR at line level, then VLM for low-confidence lines.
Returns modified paddle_results in the same format as PaddleOCR output.
Args:
image: PIL Image to process
ocr: PaddleOCR instance (optional, uses self.paddle_ocr if not provided)
paddle_results: PaddleOCR results in original format (List of dicts with rec_texts, rec_scores, rec_polys)
confidence_threshold: Confidence threshold below which VLM is used
padding: Padding to add around line crops
image_name: Name of the image for logging/debugging
input_image_width: Original image width (before preprocessing)
input_image_height: Original image height (before preprocessing)
Returns:
Modified paddle_results with VLM replacements for low-confidence lines
"""
if ocr is None:
if hasattr(self, "paddle_ocr") and self.paddle_ocr is not None:
ocr = self.paddle_ocr
else:
raise ValueError(
"No OCR object provided and 'paddle_ocr' is not initialized."
)
if paddle_results is None or not paddle_results:
return paddle_results
print("Starting hybrid PaddleOCR + VLM OCR process...")
# Get image dimensions
img_width, img_height = image.size
# Use original dimensions if provided, otherwise use current image dimensions
if input_image_width is None:
input_image_width = img_width
if input_image_height is None:
input_image_height = img_height
# Create a deep copy of paddle_results to modify
modified_paddle_results = copy.deepcopy(paddle_results)
# Process each page result in paddle_results
for page_result in modified_paddle_results:
# Extract text recognition results from the paddle format
rec_texts = page_result.get("rec_texts", list())
rec_scores = page_result.get("rec_scores", list())
rec_polys = page_result.get("rec_polys", list())
# Initialize rec_models list with "Paddle" as default for all lines
num_lines = len(rec_texts)
if (
"rec_models" not in page_result
or len(page_result.get("rec_models", [])) != num_lines
):
rec_models = ["Paddle"] * num_lines
page_result["rec_models"] = rec_models
else:
rec_models = page_result["rec_models"]
# Get image dimensions from result if available
result_image_width = page_result.get("image_width")
result_image_height = page_result.get("image_height")
# Determine PaddleOCR's coordinate space dimensions
max_x_coord = 0
max_y_coord = 0
for bounding_box in rec_polys:
if hasattr(bounding_box, "tolist"):
box = bounding_box.tolist()
else:
box = bounding_box
if box and len(box) > 0:
x_coords = [p[0] for p in box]
y_coords = [p[1] for p in box]
max_x_coord = max(max_x_coord, max(x_coords) if x_coords else 0)
max_y_coord = max(max_y_coord, max(y_coords) if y_coords else 0)
paddle_coord_width = (
result_image_width
if result_image_width is not None
else max_x_coord if max_x_coord > 0 else input_image_width
)
paddle_coord_height = (
result_image_height
if result_image_height is not None
else max_y_coord if max_y_coord > 0 else input_image_height
)
if paddle_coord_width is None or paddle_coord_height is None:
paddle_coord_width = input_image_width or img_width
paddle_coord_height = input_image_height or img_height
if paddle_coord_width <= 0 or paddle_coord_height <= 0:
paddle_coord_width = input_image_width or img_width
paddle_coord_height = input_image_height or img_height
# Process each line
# print(f"Processing {num_lines} lines from PaddleOCR results...")
for i in range(num_lines):
line_text = rec_texts[i]
line_conf = float(rec_scores[i]) * 100 # Convert to percentage
bounding_box = rec_polys[i]
# Skip empty lines
if not line_text.strip():
continue
# Extract bounding box coordinates
if hasattr(bounding_box, "tolist"):
box = bounding_box.tolist()
else:
box = bounding_box
if not box or len(box) == 0:
continue
# Convert polygon to bounding box
x_coords = [p[0] for p in box]
y_coords = [p[1] for p in box]
line_left_paddle = float(min(x_coords))
line_top_paddle = float(min(y_coords))
line_right_paddle = float(max(x_coords))
line_bottom_paddle = float(max(y_coords))
line_width_paddle = line_right_paddle - line_left_paddle
line_height_paddle = line_bottom_paddle - line_top_paddle
# Convert to image coordinate space (scale from paddle coordinates to image coordinates)
if paddle_coord_width > 0 and paddle_coord_height > 0:
rel_left = line_left_paddle / paddle_coord_width
rel_top = line_top_paddle / paddle_coord_height
rel_width = line_width_paddle / paddle_coord_width
rel_height = line_height_paddle / paddle_coord_height
line_left = rel_left * img_width
line_top = rel_top * img_height
line_width = rel_width * img_width
line_height = rel_height * img_height
else:
line_left = line_left_paddle
line_top = line_top_paddle
line_width = line_width_paddle
line_height = line_height_paddle
# Initialize model as PaddleOCR (default)
# Count words in PaddleOCR output
paddle_words = line_text.split()
paddle_word_count = len(paddle_words)
# If confidence is low, use VLM for a second opinion
if line_conf < confidence_threshold:
# Debug: Print line dimensions before cropping
# print(
# f" Line {i}: '{line_text[:50]}...' "
# f"conf={line_conf}, "
# f"bbox=({line_left:.1f}, {line_top:.1f}, {line_width:.1f}, {line_height:.1f})"
# )
# Ensure minimum line height for VLM processing
# If line_height is too small, use a minimum height based on typical text line height
min_line_height = max(
line_height, 20
) # Minimum 20 pixels for text line
# Calculate crop coordinates
crop_left = line_left
crop_top = line_top
crop_right = line_left + line_width
crop_bottom = line_top + min_line_height
# print(
# f" Crop coordinates: left={crop_left}, top={crop_top}, "
# f"right={crop_right}, bottom={crop_bottom}, "
# f"size=({crop_right - crop_left}x{crop_bottom - crop_top})"
# )
# Ensure crop dimensions are valid
if crop_right <= crop_left or crop_bottom <= crop_top:
# Invalid crop, keep original PaddleOCR result
continue
# Crop the line image
cropped_image = image.crop(
(crop_left, crop_top, crop_right, crop_bottom)
)
# Check if cropped image is too small for VLM processing
crop_width = crop_right - crop_left
crop_height = crop_bottom - crop_top
if crop_width < 10 or crop_height < 10:
# print(
# f" Line: '{line_text}' (conf: {line_conf}) -> "
# f"Cropped image too small ({crop_width}x{crop_height} pixels). "
# f"Skipping VLM, keeping PaddleOCR result."
# )
# Keep original PaddleOCR result for this line
continue
# Ensure cropped image is in RGB mode before passing to VLM
if cropped_image.mode != "RGB":
cropped_image = cropped_image.convert("RGB")
# Save input image for debugging if environment variable is set
if SAVE_VLM_INPUT_IMAGES:
try:
vlm_debug_dir = os.path.join(
OUTPUT_FOLDER,
"hybrid_paddle_vlm_visualisations/vlm_input_images",
)
os.makedirs(vlm_debug_dir, exist_ok=True)
line_text_safe = safe_sanitize_text(line_text)
line_text_shortened = line_text_safe[:20]
image_name_safe = safe_sanitize_text(image_name)
image_name_shortened = image_name_safe[:20]
filename = f"{image_name_shortened}_{line_text_shortened}_vlm_input_image.png"
filepath = os.path.join(vlm_debug_dir, filename)
cropped_image.save(filepath)
# print(f"Saved VLM input image to: {filepath}")
except Exception as save_error:
print(
f"Warning: Could not save VLM input image: {save_error}"
)
# Use VLM for OCR on this line with error handling
vlm_result = None
vlm_rec_texts = []
vlm_rec_scores = []
try:
vlm_result = _vlm_ocr_predict(cropped_image)
vlm_rec_texts = (
vlm_result.get("rec_texts", []) if vlm_result else []
)
vlm_rec_scores = (
vlm_result.get("rec_scores", []) if vlm_result else []
)
except Exception:
# print(
# f" VLM OCR failed for line '{line_text[:50]}...' (conf: {line_conf}): {vlm_error}. "
# f"Keeping original PaddleOCR result."
# )
# Ensure we keep original PaddleOCR result on error
vlm_rec_texts = []
vlm_rec_scores = []
if vlm_rec_texts and vlm_rec_scores:
# Combine VLM words into a single text string
vlm_text = " ".join(vlm_rec_texts)
vlm_word_count = len(vlm_rec_texts)
vlm_conf = float(
np.median(vlm_rec_scores)
) # Keep as 0-1 range for paddle format
# Only replace if word counts match
if (
vlm_word_count - paddle_word_count <= 2
and vlm_word_count - paddle_word_count >= -2
):
print(
f" Re-OCR'd line: '{line_text}' (conf: {line_conf:.1f}, words: {paddle_word_count}) "
f"-> '{vlm_text}' (conf: {vlm_conf*100:.1f}, words: {vlm_word_count}) [VLM]"
)
# For exporting example image comparisons
safe_filename = self._create_safe_filename_with_confidence(
line_text,
vlm_text,
int(line_conf),
int(vlm_conf * 100),
"VLM",
)
if SAVE_EXAMPLE_HYBRID_IMAGES is True:
# Normalize and validate image_name to prevent path traversal attacks
normalized_image_name = os.path.normpath(
image_name + "_hybrid_paddle_vlm"
)
if (
".." in normalized_image_name
or "/" in normalized_image_name
or "\\" in normalized_image_name
):
normalized_image_name = "safe_image"
hybrid_ocr_examples_folder = (
self.output_folder
+ f"/hybrid_ocr_examples/{normalized_image_name}"
)
# Validate the constructed path is safe
if not validate_folder_containment(
hybrid_ocr_examples_folder, OUTPUT_FOLDER
):
raise ValueError(
f"Unsafe hybrid_ocr_examples folder path: {hybrid_ocr_examples_folder}"
)
if not os.path.exists(hybrid_ocr_examples_folder):
os.makedirs(hybrid_ocr_examples_folder)
output_image_path = (
hybrid_ocr_examples_folder + f"/{safe_filename}.png"
)
# print(f"Saving example image to {output_image_path}")
cropped_image.save(output_image_path)
# Replace with VLM result in paddle_results format
# Update rec_texts, rec_scores, and rec_models for this line
rec_texts[i] = vlm_text
rec_scores[i] = vlm_conf
rec_models[i] = "VLM"
# Ensure page_result is updated with the modified rec_models list
page_result["rec_models"] = rec_models
# print(
# f" Set rec_models[{i}] = 'VLM' for line '{vlm_text[:50]}...'"
# )
else:
print(
f" Line: '{line_text}' (conf: {line_conf:.1f}, words: {paddle_word_count}) -> "
f"VLM result '{vlm_text}' (conf: {vlm_conf*100:.1f}, words: {vlm_word_count}) "
f"word count mismatch. Keeping PaddleOCR result."
)
else:
# VLM returned empty or no results - keep original PaddleOCR result
if line_conf < confidence_threshold:
pass
# print(
# f" Line: '{line_text}' (conf: {line_conf:.1f}) -> "
# f"VLM returned no results. Keeping original PaddleOCR result."
# )
# Debug: Print summary of model labels before returning
for page_idx, page_result in enumerate(modified_paddle_results):
rec_models = page_result.get("rec_models", [])
sum(1 for m in rec_models if m == "VLM")
sum(1 for m in rec_models if m == "Paddle")
return modified_paddle_results
def perform_ocr(
self, image: Union[str, Image.Image, np.ndarray], ocr: Optional[Any] = None
) -> List[OCRResult]:
"""
Performs OCR on the given image using the configured engine.
"""
if isinstance(image, str):
image_path = image
image_name = os.path.basename(image)
image = Image.open(image)
elif isinstance(image, np.ndarray):
image = Image.fromarray(image)
image_path = ""
image_name = "unknown_image_name"
# Pre-process image
# Store original dimensions BEFORE preprocessing (needed for coordinate conversion)
original_image_width = None
original_image_height = None
original_image_for_visualization = (
None # Store original image for visualization
)
if PREPROCESS_LOCAL_OCR_IMAGES:
# print("Pre-processing image...")
# Get original dimensions before preprocessing
original_image_width, original_image_height = image.size
# Store original image for visualization (coordinates are in original space)
original_image_for_visualization = image.copy()
image, preprocessing_metadata = self.image_preprocessor.preprocess_image(
image
)
if SAVE_PREPROCESS_IMAGES:
# print("Saving pre-processed image...")
image_basename = os.path.basename(image_name)
output_path = os.path.join(
self.output_folder,
"preprocessed_images",
image_basename + "_preprocessed_image.png",
)
os.makedirs(os.path.dirname(output_path), exist_ok=True)
image.save(output_path)
# print(f"Pre-processed image saved to {output_path}")
else:
preprocessing_metadata = dict()
original_image_width, original_image_height = image.size
# When preprocessing is disabled, the current image is the original
original_image_for_visualization = image.copy()
image_width, image_height = image.size
# Store original image for line-to-word conversion when PaddleOCR processes original image
original_image_for_cropping = None
paddle_processed_original = False
# Note: In testing I haven't seen that this necessarily improves results
if self.ocr_engine == "hybrid-paddle":
# Try hybrid with original image for cropping:
ocr_data = self._perform_hybrid_ocr(image, image_name=image_name)
elif self.ocr_engine == "hybrid-vlm":
# Try hybrid VLM with original image for cropping:
ocr_data = self._perform_hybrid_ocr(image, image_name=image_name)
elif self.ocr_engine == "tesseract":
ocr_data = pytesseract.image_to_data(
image,
output_type=pytesseract.Output.DICT,
config=self.tesseract_config,
lang=self.tesseract_lang, # Ensure the Tesseract language data (e.g., fra.traineddata) is installed on your system.
)
if TESSERACT_WORD_LEVEL_OCR is False:
ocr_df = pd.DataFrame(ocr_data)
# Filter out invalid entries (confidence == -1)
ocr_df = ocr_df[ocr_df.conf != -1]
# Group by line and aggregate text
line_groups = ocr_df.groupby(["block_num", "par_num", "line_num"])
ocr_data = line_groups.apply(self._calculate_line_bbox).reset_index()
# Convert DataFrame to dictionary of lists format expected by downstream code
ocr_data = {
"text": ocr_data["text"].tolist(),
"left": ocr_data["left"].astype(int).tolist(),
"top": ocr_data["top"].astype(int).tolist(),
"width": ocr_data["width"].astype(int).tolist(),
"height": ocr_data["height"].astype(int).tolist(),
"conf": ocr_data["conf"].tolist(),
"model": ["Tesseract"] * len(ocr_data), # Add model field
}
elif self.ocr_engine == "paddle" or self.ocr_engine == "hybrid-paddle-vlm":
if ocr is None:
if hasattr(self, "paddle_ocr") and self.paddle_ocr is not None:
ocr = self.paddle_ocr
else:
raise ValueError(
"No OCR object provided and 'paddle_ocr' is not initialised."
)
if not image_path:
image_np = np.array(image) # image_processed
# Check that sizes are the same
image_np_height, image_np_width = image_np.shape[:2]
if image_np_width != image_width or image_np_height != image_height:
raise ValueError(
f"Image size mismatch: {image_np_width}x{image_np_height} != {image_width}x{image_height}"
)
# PaddleOCR may need an RGB image. Ensure it has 3 channels.
if len(image_np.shape) == 2:
image_np = np.stack([image_np] * 3, axis=-1)
else:
image_np = np.array(image)
# Store dimensions of the image we're passing to PaddleOCR (preprocessed dimensions)
paddle_input_width = image_np.shape[1]
paddle_input_height = image_np.shape[0]
paddle_results = ocr.predict(image_np)
# PaddleOCR processed the preprocessed image
paddle_processed_original = False
else:
# When using image path, load image to get dimensions
temp_image = Image.open(image_path)
paddle_input_width, paddle_input_height = temp_image.size
# For file path, use the original dimensions (before preprocessing)
# original_image_width and original_image_height are already set above
paddle_results = ocr.predict(image_path)
# PaddleOCR processed the original image from file path
paddle_processed_original = True
# Store the original image for cropping
original_image_for_cropping = temp_image.copy()
# Save PaddleOCR visualization with bounding boxes
if paddle_results and SAVE_PAGE_OCR_VISUALISATIONS is True:
for res in paddle_results:
# self.output_folder is already validated and normalized at construction time
paddle_viz_folder = os.path.join(
self.output_folder, "paddle_visualisations"
)
# Double-check the constructed path is safe
if not validate_folder_containment(
paddle_viz_folder, OUTPUT_FOLDER
):
raise ValueError(
f"Unsafe paddle visualisations folder path: {paddle_viz_folder}"
)
os.makedirs(paddle_viz_folder, exist_ok=True)
res.save_to_img(paddle_viz_folder)
if self.ocr_engine == "hybrid-paddle-vlm":
paddle_results = self._perform_hybrid_paddle_vlm_ocr(
image,
ocr=ocr,
paddle_results=paddle_results,
image_name=image_name,
input_image_width=original_image_width,
input_image_height=original_image_height,
)
# Debug: Check structure after hybrid processing
if paddle_results:
if len(paddle_results) > 0 and isinstance(paddle_results[0], dict):
rec_models = paddle_results[0].get("rec_models", [])
sum(1 for m in rec_models if m == "VLM")
ocr_data = self._convert_paddle_to_tesseract_format(
paddle_results,
input_image_width=original_image_width,
input_image_height=original_image_height,
)
if SAVE_PAGE_OCR_VISUALISATIONS is True:
# Save output to image with identified bounding boxes
# Use original image since coordinates are in original image space
# Prefer original_image_for_cropping (when PaddleOCR processed from file path),
# otherwise use original_image_for_visualization (stored before preprocessing)
viz_image = (
original_image_for_cropping
if original_image_for_cropping is not None
else (
original_image_for_visualization
if original_image_for_visualization is not None
else image
)
)
if isinstance(viz_image, Image.Image):
# Convert PIL Image to numpy array in BGR format for OpenCV
image_cv = cv2.cvtColor(np.array(viz_image), cv2.COLOR_RGB2BGR)
else:
image_cv = np.array(viz_image)
if len(image_cv.shape) == 2:
image_cv = cv2.cvtColor(image_cv, cv2.COLOR_GRAY2BGR)
elif len(image_cv.shape) == 3 and image_cv.shape[2] == 3:
# Assume RGB, convert to BGR
image_cv = cv2.cvtColor(image_cv, cv2.COLOR_RGB2BGR)
# Draw all bounding boxes on the image
for i in range(len(ocr_data["text"])):
left = int(ocr_data["left"][i])
top = int(ocr_data["top"][i])
width = int(ocr_data["width"][i])
height = int(ocr_data["height"][i])
# Ensure coordinates are within image bounds
left = max(0, min(left, image_cv.shape[1] - 1))
top = max(0, min(top, image_cv.shape[0] - 1))
right = max(left + 1, min(left + width, image_cv.shape[1]))
bottom = max(top + 1, min(top + height, image_cv.shape[0]))
cv2.rectangle(
image_cv, (left, top), (right, bottom), (0, 255, 0), 2
)
# Save the visualization once with all boxes drawn
paddle_viz_folder = os.path.join(
self.output_folder, "paddle_visualisations"
)
# Double-check the constructed path is safe
if not validate_folder_containment(paddle_viz_folder, OUTPUT_FOLDER):
raise ValueError(
f"Unsafe paddle visualisations folder path: {paddle_viz_folder}"
)
os.makedirs(paddle_viz_folder, exist_ok=True)
# Generate safe filename
if image_name:
base_name = os.path.splitext(os.path.basename(image_name))[0]
# Sanitize filename to avoid issues with special characters
base_name = safe_sanitize_text(base_name, max_length=50)
filename = f"{base_name}_ocr_visualisation.jpg"
else:
timestamp = int(time.time())
filename = f"ocr_visualisation_{timestamp}.jpg"
output_path = os.path.join(paddle_viz_folder, filename)
cv2.imwrite(output_path, image_cv)
else:
raise RuntimeError(f"Unsupported OCR engine: {self.ocr_engine}")
# Always check for scale_factor, even if preprocessing_metadata is empty
# This ensures rescaling happens correctly when preprocessing was applied
scale_factor = (
preprocessing_metadata.get("scale_factor", 1.0)
if preprocessing_metadata
else 1.0
)
if scale_factor != 1.0:
# Skip rescaling for PaddleOCR since _convert_paddle_to_tesseract_format
# already scales coordinates directly to original image dimensions
# hybrid-paddle-vlm also uses PaddleOCR and converts to original space
if self.ocr_engine == "paddle" or self.ocr_engine == "hybrid-paddle-vlm":
pass
# print(f"Skipping rescale_ocr_data for PaddleOCR (already scaled to original dimensions)")
else:
# print("rescaling ocr_data with scale_factor: ", scale_factor)
ocr_data = rescale_ocr_data(ocr_data, scale_factor)
# Convert line-level results to word-level if configured and needed
if CONVERT_LINE_TO_WORD_LEVEL and self._is_line_level_data(ocr_data):
# print("Converting line-level OCR results to word-level...")
# Check if coordinates need to be scaled to match the image we're cropping from
# For PaddleOCR: _convert_paddle_to_tesseract_format converts coordinates to original image space
# - If PaddleOCR processed the original image (image_path provided), crop from original image (no scaling)
# - If PaddleOCR processed the preprocessed image (no image_path), scale coordinates to preprocessed space and crop from preprocessed image
# For Tesseract: OCR runs on preprocessed image
# - If scale_factor != 1.0, rescale_ocr_data converted coordinates to original space, so crop from original image
# - If scale_factor == 1.0, coordinates are still in preprocessed space, so crop from preprocessed image
needs_scaling = False
crop_image = image # Default to preprocessed image
crop_image_width = image_width
crop_image_height = image_height
if (
PREPROCESS_LOCAL_OCR_IMAGES
and original_image_width
and original_image_height
):
if (
self.ocr_engine == "paddle"
or self.ocr_engine == "hybrid-paddle-vlm"
):
# PaddleOCR coordinates are converted to original space by _convert_paddle_to_tesseract_format
# hybrid-paddle-vlm also uses PaddleOCR and converts to original space
if paddle_processed_original:
# PaddleOCR processed the original image, so crop from original image
# No scaling needed - coordinates are already in original space
crop_image = original_image_for_cropping
crop_image_width = original_image_width
crop_image_height = original_image_height
needs_scaling = False
else:
# PaddleOCR processed the preprocessed image, so scale coordinates to preprocessed space
needs_scaling = True
elif self.ocr_engine == "tesseract":
# For Tesseract: if scale_factor != 1.0, rescale_ocr_data converted coordinates to original space
# So we need to crop from the original image, not the preprocessed image
if (
scale_factor != 1.0
and original_image_for_visualization is not None
):
# Coordinates are in original space, so crop from original image
crop_image = original_image_for_visualization
crop_image_width = original_image_width
crop_image_height = original_image_height
needs_scaling = False
else:
# scale_factor == 1.0, so coordinates are still in preprocessed space
# Crop from preprocessed image - no scaling needed
needs_scaling = False
if needs_scaling:
# Calculate scale factors from original to preprocessed
scale_x = image_width / original_image_width
scale_y = image_height / original_image_height
# Scale coordinates to preprocessed image space for cropping
scaled_ocr_data = {
"text": ocr_data["text"],
"left": [x * scale_x for x in ocr_data["left"]],
"top": [y * scale_y for y in ocr_data["top"]],
"width": [w * scale_x for w in ocr_data["width"]],
"height": [h * scale_y for h in ocr_data["height"]],
"conf": ocr_data["conf"],
"model": ocr_data["model"],
}
ocr_data = self._convert_line_to_word_level(
scaled_ocr_data,
crop_image_width,
crop_image_height,
crop_image,
image_name=image_name,
)
# Scale word-level results back to original image space
scale_factor_x = original_image_width / image_width
scale_factor_y = original_image_height / image_height
for i in range(len(ocr_data["left"])):
ocr_data["left"][i] = ocr_data["left"][i] * scale_factor_x
ocr_data["top"][i] = ocr_data["top"][i] * scale_factor_y
ocr_data["width"][i] = ocr_data["width"][i] * scale_factor_x
ocr_data["height"][i] = ocr_data["height"][i] * scale_factor_y
else:
# No scaling needed - coordinates match the crop image space
ocr_data = self._convert_line_to_word_level(
ocr_data,
crop_image_width,
crop_image_height,
crop_image,
image_name=image_name,
)
# The rest of your processing pipeline now works for both engines
ocr_result = ocr_data
# Filter out empty strings and low confidence results
valid_indices = [
i
for i, text in enumerate(ocr_result["text"])
if text.strip() and int(ocr_result["conf"][i]) > 0
]
# Determine default model based on OCR engine if model field is not present
if "model" in ocr_result:
# Model field exists and has correct length - use it
def get_model(idx):
return ocr_result["model"][idx]
else:
# Model field not present or incorrect length - use default based on engine
default_model = (
"Tesseract"
if self.ocr_engine == "tesseract"
else (
"Paddle"
if self.ocr_engine == "paddle"
else (
"Tesseract"
if self.ocr_engine == "hybrid-paddle"
else (
"Tesseract"
if self.ocr_engine == "hybrid-vlm"
else (
"Paddle"
if self.ocr_engine == "hybrid-paddle-vlm"
else None
)
)
)
)
)
def get_model(idx):
return default_model
output = [
OCRResult(
text=clean_unicode_text(ocr_result["text"][i]),
left=ocr_result["left"][i],
top=ocr_result["top"][i],
width=ocr_result["width"][i],
height=ocr_result["height"][i],
conf=round(float(ocr_result["conf"][i]), 0),
model=get_model(i),
)
for i in valid_indices
]
return output
def analyze_text(
self,
line_level_ocr_results: List[OCRResult],
ocr_results_with_words: Dict[str, Dict],
chosen_redact_comprehend_entities: List[str],
pii_identification_method: str = LOCAL_PII_OPTION,
comprehend_client="",
custom_entities: List[str] = custom_entities,
language: Optional[str] = DEFAULT_LANGUAGE,
nlp_analyser: AnalyzerEngine = None,
**text_analyzer_kwargs,
) -> List[CustomImageRecognizerResult]:
page_text = ""
page_text_mapping = list()
all_text_line_results = list()
comprehend_query_number = 0
if not nlp_analyser:
nlp_analyser = self.analyzer_engine
# Collect all text and create mapping
for i, line_level_ocr_result in enumerate(line_level_ocr_results):
if page_text:
page_text += " "
start_pos = len(page_text)
page_text += line_level_ocr_result.text
# Note: We're not passing line_characters here since it's not needed for this use case
page_text_mapping.append((start_pos, i, line_level_ocr_result, None))
# Determine language for downstream services
aws_language = language or getattr(self, "language", None) or "en"
valid_language_entities = nlp_analyser.registry.get_supported_entities(
languages=[language]
)
if "CUSTOM" not in valid_language_entities:
valid_language_entities.append("CUSTOM")
if "CUSTOM_FUZZY" not in valid_language_entities:
valid_language_entities.append("CUSTOM_FUZZY")
# Process using either Local or AWS Comprehend
if pii_identification_method == LOCAL_PII_OPTION:
language_supported_entities = filter_entities_for_language(
custom_entities, valid_language_entities, language
)
if language_supported_entities:
text_analyzer_kwargs["entities"] = language_supported_entities
else:
out_message = f"No relevant entities supported for language: {language}"
print(out_message)
raise Warning(out_message)
analyzer_result = nlp_analyser.analyze(
text=page_text, language=language, **text_analyzer_kwargs
)
all_text_line_results = map_back_entity_results(
analyzer_result, page_text_mapping, all_text_line_results
)
elif pii_identification_method == AWS_PII_OPTION:
# Handle custom entities first
if custom_entities:
custom_redact_entities = [
entity
for entity in chosen_redact_comprehend_entities
if entity in custom_entities
]
if custom_redact_entities:
# Filter entities to only include those supported by the language
language_supported_entities = filter_entities_for_language(
custom_redact_entities, valid_language_entities, language
)
if language_supported_entities:
text_analyzer_kwargs["entities"] = language_supported_entities
page_analyser_result = nlp_analyser.analyze(
text=page_text, language=language, **text_analyzer_kwargs
)
all_text_line_results = map_back_entity_results(
page_analyser_result, page_text_mapping, all_text_line_results
)
# Process text in batches for AWS Comprehend
current_batch = ""
current_batch_mapping = list()
batch_char_count = 0
batch_word_count = 0
for i, text_line in enumerate(line_level_ocr_results):
words = text_line.text.split()
word_start_positions = list()
current_pos = 0
for word in words:
word_start_positions.append(current_pos)
current_pos += len(word) + 1
for word_idx, word in enumerate(words):
new_batch_char_count = len(current_batch) + len(word) + 1
if batch_word_count >= 50 or new_batch_char_count >= 200:
# Process current batch
all_text_line_results = do_aws_comprehend_call(
current_batch,
current_batch_mapping,
comprehend_client,
aws_language,
text_analyzer_kwargs.get("allow_list", []),
chosen_redact_comprehend_entities,
all_text_line_results,
)
comprehend_query_number += 1
# Reset batch
current_batch = word
batch_word_count = 1
batch_char_count = len(word)
current_batch_mapping = [
(0, i, text_line, None, word_start_positions[word_idx])
]
else:
if current_batch:
current_batch += " "
batch_char_count += 1
current_batch += word
batch_char_count += len(word)
batch_word_count += 1
if (
not current_batch_mapping
or current_batch_mapping[-1][1] != i
):
current_batch_mapping.append(
(
batch_char_count - len(word),
i,
text_line,
None,
word_start_positions[word_idx],
)
)
# Process final batch if any
if current_batch:
all_text_line_results = do_aws_comprehend_call(
current_batch,
current_batch_mapping,
comprehend_client,
aws_language,
text_analyzer_kwargs.get("allow_list", []),
chosen_redact_comprehend_entities,
all_text_line_results,
)
comprehend_query_number += 1
# Process results and create bounding boxes
combined_results = list()
for i, text_line in enumerate(line_level_ocr_results):
line_results = next(
(results for idx, results in all_text_line_results if idx == i), []
)
if line_results and i < len(ocr_results_with_words):
child_level_key = list(ocr_results_with_words.keys())[i]
ocr_results_with_words_line_level = ocr_results_with_words[
child_level_key
]
for result in line_results:
bbox_results = self.map_analyzer_results_to_bounding_boxes(
[result],
[
OCRResult(
text=text_line.text[result.start : result.end],
left=text_line.left,
top=text_line.top,
width=text_line.width,
height=text_line.height,
conf=text_line.conf,
)
],
text_line.text,
text_analyzer_kwargs.get("allow_list", []),
ocr_results_with_words_line_level,
)
combined_results.extend(bbox_results)
return combined_results, comprehend_query_number
@staticmethod
def map_analyzer_results_to_bounding_boxes(
text_analyzer_results: List[RecognizerResult],
redaction_relevant_ocr_results: List[OCRResult],
full_text: str,
allow_list: List[str],
ocr_results_with_words_child_info: Dict[str, Dict],
) -> List[CustomImageRecognizerResult]:
redaction_bboxes = list()
for redaction_relevant_ocr_result in redaction_relevant_ocr_results:
line_text = ocr_results_with_words_child_info["text"]
line_length = len(line_text)
redaction_text = redaction_relevant_ocr_result.text
for redaction_result in text_analyzer_results:
# Check if the redaction text is not in the allow list
if redaction_text not in allow_list:
# Adjust start and end to be within line bounds
start_in_line = max(0, redaction_result.start)
end_in_line = min(line_length, redaction_result.end)
# Get the matched text from this line
matched_text = line_text[start_in_line:end_in_line]
matched_text.split()
# Find the corresponding words in the OCR results
matching_word_boxes = list()
current_position = 0
for word_info in ocr_results_with_words_child_info.get("words", []):
word_text = word_info["text"]
word_length = len(word_text)
word_start = current_position
word_end = current_position + word_length
# Update current position for the next word
current_position += (
word_length + 1
) # +1 for the space after the word
# Check if the word's bounding box is within the start and end bounds
if word_start >= start_in_line and word_end <= (
end_in_line + 1
):
matching_word_boxes.append(word_info["bounding_box"])
if matching_word_boxes:
# Calculate the combined bounding box for all matching words
left = min(box[0] for box in matching_word_boxes)
top = min(box[1] for box in matching_word_boxes)
right = max(box[2] for box in matching_word_boxes)
bottom = max(box[3] for box in matching_word_boxes)
redaction_bboxes.append(
CustomImageRecognizerResult(
entity_type=redaction_result.entity_type,
start=start_in_line,
end=end_in_line,
score=round(redaction_result.score, 2),
left=left,
top=top,
width=right - left,
height=bottom - top,
text=matched_text,
)
)
return redaction_bboxes
@staticmethod
def remove_space_boxes(ocr_result: dict) -> dict:
"""Remove OCR bboxes that are for spaces.
:param ocr_result: OCR results (raw or thresholded).
:return: OCR results with empty words removed.
"""
# Get indices of items with no text
idx = list()
for i, text in enumerate(ocr_result["text"]):
is_not_space = text.isspace() is False
if text != "" and is_not_space:
idx.append(i)
# Only retain items with text
filtered_ocr_result = {}
for key in list(ocr_result.keys()):
filtered_ocr_result[key] = [ocr_result[key][i] for i in idx]
return filtered_ocr_result
@staticmethod
def _scale_bbox_results(
ocr_result: Dict[str, List[Union[int, str]]], scale_factor: float
) -> Dict[str, float]:
"""Scale down the bounding box results based on a scale percentage.
:param ocr_result: OCR results (raw).
:param scale_percent: Scale percentage for resizing the bounding box.
:return: OCR results (scaled).
"""
scaled_results = deepcopy(ocr_result)
coordinate_keys = ["left", "top"]
dimension_keys = ["width", "height"]
for coord_key in coordinate_keys:
scaled_results[coord_key] = [
int(np.ceil((x) / (scale_factor))) for x in scaled_results[coord_key]
]
for dim_key in dimension_keys:
scaled_results[dim_key] = [
max(1, int(np.ceil(x / (scale_factor))))
for x in scaled_results[dim_key]
]
return scaled_results
@staticmethod
def estimate_x_offset(full_text: str, start: int) -> int:
# Estimate the x-offset based on character position
# This is a simple estimation and might need refinement for variable-width fonts
return int(start / len(full_text) * len(full_text))
def estimate_width(self, ocr_result: OCRResult, start: int, end: int) -> int:
# Extract the relevant text portion
relevant_text = ocr_result.text[start:end]
# If the relevant text is the same as the full text, return the full width
if relevant_text == ocr_result.text:
return ocr_result.width
# Estimate width based on the proportion of the relevant text length to the total text length
total_text_length = len(ocr_result.text)
relevant_text_length = len(relevant_text)
if total_text_length == 0:
return 0 # Avoid division by zero
# Proportion of the relevant text to the total text
proportion = relevant_text_length / total_text_length
# Estimate the width based on the proportion
estimated_width = int(proportion * ocr_result.width)
return estimated_width
def bounding_boxes_overlap(box1: List, box2: List):
"""Check if two bounding boxes overlap."""
return (
box1[0] < box2[2]
and box2[0] < box1[2]
and box1[1] < box2[3]
and box2[1] < box1[3]
)
def map_back_entity_results(
page_analyser_result: dict,
page_text_mapping: dict,
all_text_line_results: List[Tuple],
):
for entity in page_analyser_result:
entity_start = entity.start
entity_end = entity.end
# Track if the entity has been added to any line
added_to_line = False
for batch_start, line_idx, original_line, chars in page_text_mapping:
batch_end = batch_start + len(original_line.text)
# Check if the entity overlaps with the current line
if (
batch_start < entity_end and batch_end > entity_start
): # Overlap condition
relative_start = max(
0, entity_start - batch_start
) # Adjust start relative to the line
relative_end = min(
entity_end - batch_start, len(original_line.text)
) # Adjust end relative to the line
# Create a new adjusted entity
adjusted_entity = copy.deepcopy(entity)
adjusted_entity.start = relative_start
adjusted_entity.end = relative_end
# Check if this line already has an entry
existing_entry = next(
(entry for idx, entry in all_text_line_results if idx == line_idx),
None,
)
if existing_entry is None:
all_text_line_results.append((line_idx, [adjusted_entity]))
else:
existing_entry.append(
adjusted_entity
) # Append to the existing list of entities
added_to_line = True
# If the entity spans multiple lines, you may want to handle that here
if not added_to_line:
# Handle cases where the entity does not fit in any line (optional)
print(f"Entity '{entity}' does not fit in any line.")
return all_text_line_results
def map_back_comprehend_entity_results(
response: object,
current_batch_mapping: List[Tuple],
allow_list: List[str],
chosen_redact_comprehend_entities: List[str],
all_text_line_results: List[Tuple],
):
if not response or "Entities" not in response:
return all_text_line_results
for entity in response["Entities"]:
if entity.get("Type") not in chosen_redact_comprehend_entities:
continue
entity_start = entity["BeginOffset"]
entity_end = entity["EndOffset"]
# Track if the entity has been added to any line
added_to_line = False
# Find the correct line and offset within that line
for (
batch_start,
line_idx,
original_line,
chars,
line_offset,
) in current_batch_mapping:
batch_end = batch_start + len(original_line.text[line_offset:])
# Check if the entity overlaps with the current line
if (
batch_start < entity_end and batch_end > entity_start
): # Overlap condition
# Calculate the absolute position within the line
relative_start = max(0, entity_start - batch_start + line_offset)
relative_end = min(
entity_end - batch_start + line_offset, len(original_line.text)
)
result_text = original_line.text[relative_start:relative_end]
if result_text not in allow_list:
adjusted_entity = entity.copy()
adjusted_entity["BeginOffset"] = (
relative_start # Now relative to the full line
)
adjusted_entity["EndOffset"] = relative_end
recogniser_entity = recognizer_result_from_dict(adjusted_entity)
existing_entry = next(
(
entry
for idx, entry in all_text_line_results
if idx == line_idx
),
None,
)
if existing_entry is None:
all_text_line_results.append((line_idx, [recogniser_entity]))
else:
existing_entry.append(
recogniser_entity
) # Append to the existing list of entities
added_to_line = True
# Optional: Handle cases where the entity does not fit in any line
if not added_to_line:
print(f"Entity '{entity}' does not fit in any line.")
return all_text_line_results
def do_aws_comprehend_call(
current_batch: str,
current_batch_mapping: List[Tuple],
comprehend_client: botocore.client.BaseClient,
language: str,
allow_list: List[str],
chosen_redact_comprehend_entities: List[str],
all_text_line_results: List[Tuple],
):
if not current_batch:
return all_text_line_results
max_retries = 3
retry_delay = 3
for attempt in range(max_retries):
try:
response = comprehend_client.detect_pii_entities(
Text=current_batch.strip(), LanguageCode=language
)
all_text_line_results = map_back_comprehend_entity_results(
response,
current_batch_mapping,
allow_list,
chosen_redact_comprehend_entities,
all_text_line_results,
)
return all_text_line_results
except Exception as e:
if attempt == max_retries - 1:
print("AWS Comprehend calls failed due to", e)
raise
time.sleep(retry_delay)
def run_page_text_redaction(
language: str,
chosen_redact_entities: List[str],
chosen_redact_comprehend_entities: List[str],
line_level_text_results_list: List[str],
line_characters: List,
page_analyser_results: List = list(),
page_analysed_bounding_boxes: List = list(),
comprehend_client=None,
allow_list: List[str] = None,
pii_identification_method: str = LOCAL_PII_OPTION,
nlp_analyser: AnalyzerEngine = None,
score_threshold: float = 0.0,
custom_entities: List[str] = None,
comprehend_query_number: int = 0,
):
"""
This function performs text redaction on a page based on the specified language and chosen entities.
Args:
language (str): The language code for the text being processed.
chosen_redact_entities (List[str]): A list of entities to be redacted from the text.
chosen_redact_comprehend_entities (List[str]): A list of entities identified by AWS Comprehend for redaction.
line_level_text_results_list (List[str]): A list of text lines extracted from the page.
line_characters (List): A list of character-level information for each line of text.
page_analyser_results (List, optional): Results from previous page analysis. Defaults to an empty list.
page_analysed_bounding_boxes (List, optional): Bounding boxes for the analysed page. Defaults to an empty list.
comprehend_client: The AWS Comprehend client for making API calls. Defaults to None.
allow_list (List[str], optional): A list of allowed entities that should not be redacted. Defaults to None.
pii_identification_method (str, optional): The method used for PII identification. Defaults to LOCAL_PII_OPTION.
nlp_analyser (AnalyzerEngine, optional): The NLP analyzer engine used for local analysis. Defaults to None.
score_threshold (float, optional): The threshold score for entity detection. Defaults to 0.0.
custom_entities (List[str], optional): A list of custom entities for redaction. Defaults to None.
comprehend_query_number (int, optional): A counter for the number of Comprehend queries made. Defaults to 0.
"""
page_text = ""
page_text_mapping = list()
all_text_line_results = list()
comprehend_query_number = 0
# Collect all text from the page
for i, text_line in enumerate(line_level_text_results_list):
if chosen_redact_entities:
if page_text:
page_text += " "
start_pos = len(page_text)
page_text += text_line.text
page_text_mapping.append((start_pos, i, text_line, line_characters[i]))
valid_language_entities = nlp_analyser.registry.get_supported_entities(
languages=[language]
)
if "CUSTOM" not in valid_language_entities:
valid_language_entities.append("CUSTOM")
if "CUSTOM_FUZZY" not in valid_language_entities:
valid_language_entities.append("CUSTOM_FUZZY")
# Process based on identification method
if pii_identification_method == LOCAL_PII_OPTION:
if not nlp_analyser:
raise ValueError("nlp_analyser is required for Local identification method")
language_supported_entities = filter_entities_for_language(
chosen_redact_entities, valid_language_entities, language
)
page_analyser_result = nlp_analyser.analyze(
text=page_text,
language=language,
entities=language_supported_entities,
score_threshold=score_threshold,
return_decision_process=True,
allow_list=allow_list,
)
all_text_line_results = map_back_entity_results(
page_analyser_result, page_text_mapping, all_text_line_results
)
elif pii_identification_method == AWS_PII_OPTION:
# Process custom entities if any
if custom_entities:
custom_redact_entities = [
entity
for entity in chosen_redact_comprehend_entities
if entity in custom_entities
]
language_supported_entities = filter_entities_for_language(
custom_redact_entities, valid_language_entities, language
)
if language_supported_entities:
page_analyser_result = nlp_analyser.analyze(
text=page_text,
language=language,
entities=language_supported_entities,
score_threshold=score_threshold,
return_decision_process=True,
allow_list=allow_list,
)
all_text_line_results = map_back_entity_results(
page_analyser_result, page_text_mapping, all_text_line_results
)
current_batch = ""
current_batch_mapping = list()
batch_char_count = 0
batch_word_count = 0
for i, text_line in enumerate(line_level_text_results_list):
words = text_line.text.split()
word_start_positions = list()
# Calculate word start positions within the line
current_pos = 0
for word in words:
word_start_positions.append(current_pos)
current_pos += len(word) + 1 # +1 for space
for word_idx, word in enumerate(words):
new_batch_char_count = len(current_batch) + len(word) + 1
if batch_word_count >= 50 or new_batch_char_count >= 200:
# Process current batch
all_text_line_results = do_aws_comprehend_call(
current_batch,
current_batch_mapping,
comprehend_client,
language,
allow_list,
chosen_redact_comprehend_entities,
all_text_line_results,
)
comprehend_query_number += 1
# Start new batch
current_batch = word
batch_word_count = 1
batch_char_count = len(word)
current_batch_mapping = [
(
0,
i,
text_line,
line_characters[i],
word_start_positions[word_idx],
)
]
else:
if current_batch:
current_batch += " "
batch_char_count += 1
current_batch += word
batch_char_count += len(word)
batch_word_count += 1
if not current_batch_mapping or current_batch_mapping[-1][1] != i:
current_batch_mapping.append(
(
batch_char_count - len(word),
i,
text_line,
line_characters[i],
word_start_positions[
word_idx
], # Add the word's start position within its line
)
)
# Process final batch
if current_batch:
all_text_line_results = do_aws_comprehend_call(
current_batch,
current_batch_mapping,
comprehend_client,
language,
allow_list,
chosen_redact_comprehend_entities,
all_text_line_results,
)
comprehend_query_number += 1
# Process results for each line
for i, text_line in enumerate(line_level_text_results_list):
line_results = next(
(results for idx, results in all_text_line_results if idx == i), []
)
if line_results:
text_line_bounding_boxes = merge_text_bounding_boxes(
line_results, line_characters[i]
)
page_analyser_results.extend(line_results)
page_analysed_bounding_boxes.extend(text_line_bounding_boxes)
return page_analysed_bounding_boxes
def merge_text_bounding_boxes(
analyser_results: dict,
characters: List[LTChar],
combine_pixel_dist: int = 20,
vertical_padding: int = 0,
):
"""
Merge identified bounding boxes containing PII that are very close to one another
"""
analysed_bounding_boxes = list()
original_bounding_boxes = list() # List to hold original bounding boxes
if len(analyser_results) > 0 and len(characters) > 0:
# Extract bounding box coordinates for sorting
bounding_boxes = list()
for result in analyser_results:
char_boxes = [
char.bbox
for char in characters[result.start : result.end]
if isinstance(char, LTChar)
]
char_text = [
char._text
for char in characters[result.start : result.end]
if isinstance(char, LTChar)
]
if char_boxes:
# Calculate the bounding box that encompasses all characters
left = min(box[0] for box in char_boxes)
bottom = min(box[1] for box in char_boxes)
right = max(box[2] for box in char_boxes)
top = max(box[3] for box in char_boxes) + vertical_padding
bbox = [left, bottom, right, top]
bounding_boxes.append(
(bottom, left, result, bbox, char_text)
) # (y, x, result, bbox, text)
# Store original bounding boxes
original_bounding_boxes.append(
{
"text": "".join(char_text),
"boundingBox": bbox,
"result": copy.deepcopy(result),
}
)
# print("Original bounding boxes:", original_bounding_boxes)
# Sort the results by y-coordinate and then by x-coordinate
bounding_boxes.sort()
merged_bounding_boxes = list()
current_box = None
current_y = None
current_result = None
current_text = list()
for y, x, result, next_box, text in bounding_boxes:
if current_y is None or current_box is None:
# Initialize the first bounding box
current_box = next_box
current_y = next_box[1]
current_result = result
current_text = list(text)
else:
vertical_diff_bboxes = abs(next_box[1] - current_y)
horizontal_diff_bboxes = abs(next_box[0] - current_box[2])
if (
vertical_diff_bboxes <= 5
and horizontal_diff_bboxes <= combine_pixel_dist
):
# Merge bounding boxes
# print("Merging boxes")
merged_box = current_box.copy()
merged_result = current_result
merged_text = current_text.copy()
merged_box[2] = next_box[2] # Extend horizontally
merged_box[3] = max(current_box[3], next_box[3]) # Adjust the top
merged_result.end = max(
current_result.end, result.end
) # Extend text range
try:
if current_result.entity_type != result.entity_type:
merged_result.entity_type = (
current_result.entity_type + " - " + result.entity_type
)
else:
merged_result.entity_type = current_result.entity_type
except Exception as e:
print("Unable to combine result entity types:", e)
if current_text:
merged_text.append(" ") # Add space between texts
merged_text.extend(text)
merged_bounding_boxes.append(
{
"text": "".join(merged_text),
"boundingBox": merged_box,
"result": merged_result,
}
)
else:
# Start a new bounding box
current_box = next_box
current_y = next_box[1]
current_result = result
current_text = list(text)
# Combine original and merged bounding boxes
analysed_bounding_boxes.extend(original_bounding_boxes)
analysed_bounding_boxes.extend(merged_bounding_boxes)
# print("Analysed bounding boxes:", analysed_bounding_boxes)
return analysed_bounding_boxes
def recreate_page_line_level_ocr_results_with_page(
page_line_level_ocr_results_with_words: dict,
):
reconstructed_results = list()
# Assume all lines belong to the same page, so we can just read it from one item
# page = next(iter(page_line_level_ocr_results_with_words.values()))["page"]
page = page_line_level_ocr_results_with_words["page"]
for line_data in page_line_level_ocr_results_with_words["results"].values():
bbox = line_data["bounding_box"]
text = line_data["text"]
if line_data["line"]:
line_number = line_data["line"]
if "conf" in line_data["words"][0]:
conf = sum(word["conf"] for word in line_data["words"]) / len(
line_data["words"]
)
else:
conf = 0.0
# Recreate the OCRResult
line_result = OCRResult(
text=text,
left=bbox[0],
top=bbox[1],
width=bbox[2] - bbox[0],
height=bbox[3] - bbox[1],
line=line_number,
conf=round(float(conf), 0),
)
reconstructed_results.append(line_result)
page_line_level_ocr_results_with_page = {
"page": page,
"results": reconstructed_results,
}
return page_line_level_ocr_results_with_page
def split_words_and_punctuation_from_line(
line_of_words: List[OCRResult],
) -> List[OCRResult]:
"""
Takes a list of OCRResult objects and splits words with trailing/leading punctuation.
For a word like "example.", it creates two new OCRResult objects for "example"
and "." and estimates their bounding boxes. Words with internal hyphens like
"high-tech" are preserved.
"""
# Punctuation that will be split off. Hyphen is not included.
new_word_list = list()
for word_result in line_of_words:
word_text = word_result.text
# This regex finds a central "core" word, and captures leading and trailing punctuation
# Handles cases like "(word)." -> group1='(', group2='word', group3='.'
match = re.match(r"([(\[{]*)(.*?)_?([.,?!:;)\}\]]*)$", word_text)
# Handle words with internal hyphens that might confuse the regex
if "-" in word_text and not match.group(2):
core_part_text = word_text
leading_punc = ""
trailing_punc = ""
elif match:
leading_punc, core_part_text, trailing_punc = match.groups()
else: # Failsafe
new_word_list.append(word_result)
continue
# If no split is needed, just add the original and continue
if not leading_punc and not trailing_punc:
new_word_list.append(word_result)
continue
# --- A split is required ---
# Estimate new bounding boxes by proportionally allocating width
original_width = word_result.width
if not word_text or original_width == 0:
continue # Failsafe
avg_char_width = original_width / len(word_text)
current_left = word_result.left
# Add leading punctuation if it exists
if leading_punc:
punc_width = avg_char_width * len(leading_punc)
new_word_list.append(
OCRResult(
text=leading_punc,
left=current_left,
top=word_result.top,
width=punc_width,
height=word_result.height,
conf=word_result.conf,
)
)
current_left += punc_width
# Add the core part of the word
if core_part_text:
core_width = avg_char_width * len(core_part_text)
new_word_list.append(
OCRResult(
text=core_part_text,
left=current_left,
top=word_result.top,
width=core_width,
height=word_result.height,
conf=word_result.conf,
)
)
current_left += core_width
# Add trailing punctuation if it exists
if trailing_punc:
punc_width = avg_char_width * len(trailing_punc)
new_word_list.append(
OCRResult(
text=trailing_punc,
left=current_left,
top=word_result.top,
width=punc_width,
height=word_result.height,
conf=word_result.conf,
)
)
return new_word_list
def create_ocr_result_with_children(
combined_results: dict, i: int, current_bbox: dict, current_line: list
):
combined_results["text_line_" + str(i)] = {
"line": i,
"text": current_bbox.text,
"bounding_box": (
current_bbox.left,
current_bbox.top,
current_bbox.left + current_bbox.width,
current_bbox.top + current_bbox.height,
),
"words": [
{
"text": word.text,
"bounding_box": (
word.left,
word.top,
word.left + word.width,
word.top + word.height,
),
"conf": word.conf,
"model": word.model,
}
for word in current_line
],
"conf": current_bbox.conf,
}
return combined_results["text_line_" + str(i)]
def combine_ocr_results(
ocr_results: List[OCRResult],
x_threshold: float = 50.0,
y_threshold: float = 12.0,
page: int = 1,
):
"""
Group OCR results into lines, splitting words from punctuation.
"""
if not ocr_results:
return {"page": page, "results": []}, {"page": page, "results": {}}
lines = list()
current_line = list()
for result in sorted(ocr_results, key=lambda x: (x.top, x.left)):
if not current_line or abs(result.top - current_line[0].top) <= y_threshold:
current_line.append(result)
else:
lines.append(sorted(current_line, key=lambda x: x.left))
current_line = [result]
if current_line:
lines.append(sorted(current_line, key=lambda x: x.left))
page_line_level_ocr_results = list()
page_line_level_ocr_results_with_words = {}
line_counter = 1
for line in lines:
if not line:
continue
# Process the line to split punctuation from words
processed_line = split_words_and_punctuation_from_line(line)
# Re-calculate the line-level text and bounding box from the ORIGINAL words
line_text = " ".join([word.text for word in line])
line_left = line[0].left
line_top = min(word.top for word in line)
line_right = max(word.left + word.width for word in line)
line_bottom = max(word.top + word.height for word in line)
line_conf = round(
sum(word.conf for word in line) / len(line), 0
) # This is mean confidence for the line
final_line_bbox = OCRResult(
text=line_text,
left=line_left,
top=line_top,
width=line_right - line_left,
height=line_bottom - line_top,
line=line_counter,
conf=line_conf,
)
page_line_level_ocr_results.append(final_line_bbox)
# Use the PROCESSED line to create the children. Creates a result within page_line_level_ocr_results_with_words
page_line_level_ocr_results_with_words["text_line_" + str(line_counter)] = (
create_ocr_result_with_children(
page_line_level_ocr_results_with_words,
line_counter,
final_line_bbox,
processed_line,
)
)
line_counter += 1
page_level_results_with_page = {
"page": page,
"results": page_line_level_ocr_results,
}
page_level_results_with_words = {
"page": page,
"results": page_line_level_ocr_results_with_words,
}
return page_level_results_with_page, page_level_results_with_words