app.py

import cv2
import gradio as gr
import numpy as np
from PIL import Image, ImageDraw
from ultralytics import YOLO
import logging
import math

# Set up logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Global variables to store line coordinates and line equation
start_point = None
end_point = None
line_params = None  # Stores (slope, intercept) of the line

def extract_first_frame(stream_url):
    """
    Extracts the first available frame from the IP camera stream and returns it as a PIL image.
    """
    logger.info("Attempting to extract the first frame from the stream...")
    cap = cv2.VideoCapture(stream_url)
    if not cap.isOpened():
        logger.error("Error: Could not open stream.")
        return None, "Error: Could not open stream."

    ret, frame = cap.read()
    cap.release()

    if not ret:
        logger.error("Error: Could not read the first frame.")
        return None, "Error: Could not read the first frame."

    # Convert the frame to a PIL image
    frame_rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
    pil_image = Image.fromarray(frame_rgb)

    logger.info("First frame extracted successfully.")
    return pil_image, "First frame extracted successfully."

def update_line(image, evt: gr.SelectData):
    """
    Updates the line based on user interaction (click and drag).
    """
    global start_point, end_point, line_params

    # If it's the first click, set the start point and show it on the image
    if start_point is None:
        start_point = (evt.index[0], evt.index[1])

        # Draw the start point on the image
        draw = ImageDraw.Draw(image)
        draw.ellipse(
            (start_point[0] - 5, start_point[1] - 5, start_point[0] + 5, start_point[1] + 5),
            fill="blue", outline="blue"
        )

        return image, f"Line Coordinates:\nStart: {start_point}, End: None"

    # If it's the second click, set the end point and draw the line
    end_point = (evt.index[0], evt.index[1])

    # Calculate the slope (m) and intercept (b) of the line: y = mx + b
    if start_point[0] != end_point[0]:  # Avoid division by zero
        slope = (end_point[1] - start_point[1]) / (end_point[0] - start_point[0])
        intercept = start_point[1] - slope * start_point[0]
        line_params = (slope, intercept, start_point, end_point)  # Store slope, intercept, and points
    else:
        # Vertical line (special case)
        line_params = (float('inf'), start_point[0], start_point, end_point)

    # Draw the line and end point on the image
    draw = ImageDraw.Draw(image)
    draw.line([start_point, end_point], fill="red", width=2)
    draw.ellipse(
        (end_point[0] - 5, end_point[1] - 5, end_point[0] + 5, end_point[1] + 5),
        fill="green", outline="green"
    )

    # Return the updated image and line info
    line_info = f"Line Coordinates:\nStart: {start_point}, End: {end_point}\nLine Equation: y = {line_params[0]:.2f}x + {line_params[1]:.2f}"

    # Reset the points for the next interaction
    start_point = None
    end_point = None

    return image, line_info

def reset_line():
    """
    Resets the line coordinates.
    """
    global start_point, end_point, line_params
    start_point = None
    end_point = None
    line_params = None
    return None, "Line reset. Click to draw a new line."

def is_object_crossing_line(box, line_params):
    """
    Determines if an object's bounding box is fully intersected by the user-drawn line.
    """
    _, _, line_start, line_end = line_params

    # Get the bounding box coordinates
    x1, y1, x2, y2 = box

    # Define the four edges of the bounding box
    box_edges = [
        ((x1, y1), (x2, y1)),  # Top edge
        ((x2, y1), (x2, y2)),  # Right edge
        ((x2, y2), (x1, y2)),  # Bottom edge
        ((x1, y2), (x1, y1))   # Left edge
    ]

    # Count the number of intersections between the line and the bounding box edges
    intersection_count = 0
    for edge_start, edge_end in box_edges:
        if intersect(line_start, line_end, edge_start, edge_end):
            intersection_count += 1

    # Only count the object if the line intersects the bounding box at least twice
    return intersection_count >= 2

def draw_angled_line(image, line_params, color=(0, 255, 0), thickness=2):
    """
    Draws the user-defined line on the frame.
    """
    _, _, start_point, end_point = line_params
    cv2.line(image, start_point, end_point, color, thickness)

def process_video(confidence_threshold=0.5, selected_classes=None, stream_url=None):
    """
    Processes the IP camera stream to count objects of the selected classes crossing the line.
    """
    global line_params

    errors = []

    if line_params is None:
        errors.append("Error: No line drawn. Please draw a line on the first frame.")
    if selected_classes is None or len(selected_classes) == 0:
        errors.append("Error: No classes selected. Please select at least one class to detect.")
    if stream_url is None or stream_url.strip() == "":
        errors.append("Error: No stream URL provided.")

    if errors:
        return None, "\n".join(errors)

    logger.info("Connecting to the IP camera stream...")
    cap = cv2.VideoCapture(stream_url)
    if not cap.isOpened():
        errors.append("Error: Could not open stream.")
        return None, "\n".join(errors)

    model = YOLO(model="yolov8n.pt")
    crossed_objects = set()  # Use a set to store unique object IDs (if available)

    logger.info("Starting to process the stream...")
    while cap.isOpened():
        ret, frame = cap.read()
        if not ret:
            errors.append("Error: Could not read frame from the stream.")
            break

        # Perform object detection (no tracking)
        results = model.predict(frame, conf=confidence_threshold)

        for result in results:
            boxes = result.boxes.xyxy.cpu().numpy()
            clss = result.boxes.cls.cpu().numpy()
            confs = result.boxes.conf.cpu().numpy()

            for box, cls, conf in zip(boxes, clss, confs):
                if conf >= confidence_threshold and model.names[int(cls)] in selected_classes:
                    # Check if the object crosses the line
                    if is_object_crossing_line(box, line_params):
                        # Use the bounding box center as a unique identifier
                        center = ((box[0] + box[2]) / 2, (box[1] + box[3]) / 2)
                        crossed_objects.add(tuple(center))  # Add the center to the set

        # Visualize the results with bounding boxes
        annotated_frame = results[0].plot()

        # Draw the angled line on the frame
        draw_angled_line(annotated_frame, line_params, color=(0, 255, 0), thickness=2)

        # Display the count on the frame
        count = len(crossed_objects)
        (text_width, text_height), _ = cv2.getTextSize(f"COUNT: {count}", cv2.FONT_HERSHEY_SIMPLEX, 1, 2)

        # Calculate the position for the middle of the top
        margin = 10  # Margin from the top
        x = (annotated_frame.shape[1] - text_width) // 2  # Center-align the text horizontally
        y = text_height + margin  # Top-align the text

        # Draw the black background rectangle
        cv2.rectangle(annotated_frame, (x - margin, y - text_height - margin), (x + text_width + margin, y + margin), (0, 0, 0), -1)

        # Draw the text
        cv2.putText(annotated_frame, f"COUNT: {count}", (x, y), cv2.FONT_HERSHEY_SIMPLEX, 1, (0, 255, 0), 2)

        # Yield the annotated frame to Gradio
        yield annotated_frame, ""

    cap.release()
    logger.info("Stream processing completed.")

# Define the Gradio interface
with gr.Blocks() as demo:
    gr.Markdown("<h1>Real-time monitoring, object tracking, and line-crossing detection for CCTV camera streams.</h1></center>")
    gr.Markdown("## https://github.com/SanshruthR/CCTV_SENTRY_YOLO11")

    # Step 1: Enter the IP Camera Stream URL
    stream_url = gr.Textbox(label="Enter IP Camera Stream URL", value="https://s104.ipcamlive.com/streams/68idokwtondsqpmkr/stream.m3u8", visible=False)

    # Step 1: Extract the first frame from the stream
    gr.Markdown("### Step 1: Click on the frame to draw a line, the objects crossing it would be counted in real-time.")
    first_frame, status = extract_first_frame(stream_url.value)
    if first_frame is None:
        gr.Markdown(f"**Error:** {status}")
    else:
        # Image component for displaying the first frame
        image = gr.Image(value=first_frame, label="First Frame of Stream", type="pil")

        line_info = gr.Textbox(label="Line Coordinates", value="Line Coordinates:\nStart: None, End: None")
        image.select(update_line, inputs=image, outputs=[image, line_info])

        # Step 2: Select classes to detect
        gr.Markdown("### Step 2: Select Classes to Detect")
        model = YOLO(model="yolov8n.pt")  # Load the model to get class names
        class_names = list(model.names.values())  # Get class names
        selected_classes = gr.CheckboxGroup(choices=class_names, label="Select Classes to Detect")

        # Step 3: Adjust confidence threshold 
        gr.Markdown("### Step 3: Adjust Confidence Threshold (Optional)")
        confidence_threshold = gr.Slider(minimum=0.0, maximum=1.0, value=0.2, label="Confidence Threshold")

        # Process the stream
        process_button = gr.Button("Process Stream")

        # Output image for real-time frame rendering
        output_image = gr.Image(label="Processed Frame", streaming=True)

        # Error box to display warnings/errors
        error_box = gr.Textbox(label="Errors/Warnings", interactive=False)

        # Event listener for processing the video
        process_button.click(process_video, inputs=[confidence_threshold, selected_classes, stream_url], outputs=[output_image, error_box])

# Launch the interface
demo.launch(debug=True)