File size: 9,023 Bytes
e6769bb
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
"""
Main recognizer class for Gregg Shorthand Recognition
"""

import torch
import torch.nn.functional as F
from PIL import Image
import numpy as np
import os
from typing import Union, List, Optional
import torchvision.transforms as transforms

from .models import Seq2SeqModel, ImageToTextModel
from .config import Seq2SeqConfig, ImageToTextConfig

class GreggRecognition:
    """
    class for recognizing Gregg shorthand from images
    """
    
    def __init__(
        self, 
        model_type: str = "image_to_text",
        device: str = "auto",
        model_path: Optional[str] = None,
        config: Optional[Union[Seq2SeqConfig, ImageToTextConfig]] = None
    ):
        """
        init GreggRecognition
        
        Args:
            model_type: "image_to_text" or "seq2seq"
            device: "auto", "cpu", or "cuda"
            model_path: Path to custom model file
            config: Custom configuration object
        """
        self.model_type = model_type
        self.device = self._setup_device(device)
        
        # handle config
        if config is None:
            if model_type == "image_to_text":
                self.config = ImageToTextConfig()
            elif model_type == "seq2seq":
                self.config = Seq2SeqConfig()
            else:
                raise ValueError(f"Unknown model type: {model_type}")
        else:
            self.config = config
        
        # init image preprocessing
        self._setup_preprocessing()
        
        self.model = self._load_model(model_path)
        
    def _setup_device(self, device: str) -> torch.device:
        """Setup the computation device"""
        if device == "auto":
            return torch.device("cuda" if torch.cuda.is_available() else "cpu")
        else:
            return torch.device(device)
    
    def _setup_preprocessing(self):
        """Setup image preprocessing pipeline"""
        if self.model_type == "image_to_text":
            self.transform = transforms.Compose([
                transforms.Grayscale(num_output_channels=1),
                transforms.Resize((self.config.image_height, self.config.image_width)),
                transforms.ToTensor(),
                transforms.Normalize(mean=[0.5], std=[0.5])  # Normalize to [-1, 1]
            ])
        else:  # seq2seq
            self.transform = transforms.Compose([
                transforms.Grayscale(num_output_channels=1),
                transforms.Resize((256, 256)),  # Default size for seq2seq
                transforms.ToTensor(),
                transforms.Normalize(mean=[0.5], std=[0.5])
            ])
    
    def _load_model(self, model_path: Optional[str]) -> torch.nn.Module:
        """Load the model"""
        if self.model_type == "image_to_text":
            model = ImageToTextModel(self.config)
        elif self.model_type == "seq2seq":
            model = Seq2SeqModel(256, 256, self.config)
        else:
            raise ValueError(f"Unknown model type: {self.model_type}")
        
        # decide model path
        if model_path is None:
            package_dir = os.path.dirname(os.path.abspath(__file__))
            if self.model_type == "image_to_text":
                model_path = os.path.join(package_dir, "models", "image_to_text_model.pth")
            elif self.model_type == "seq2seq":
                model_path = os.path.join(package_dir, "models", "seq2seq_model.pth")
        
        # load weights
        if model_path and os.path.exists(model_path):
            try:
                if hasattr(model, 'load_pretrained'):
                    success = model.load_pretrained(model_path)
                    if success:
                        print(f"loaded model")
                    else:
                        print(f"failed to load model from {model_path}")
                else:
                    checkpoint = torch.load(model_path, map_location=self.device)
                    if 'model_state_dict' in checkpoint:
                        model.load_state_dict(checkpoint['model_state_dict'])
                    else:
                        model.load_state_dict(checkpoint)
                    print(f"loaded model from {model_path}")
            except Exception as e:
                print(f"error loading model from {model_path}: {e}")
        else:
            if model_path:
                print(f"model file not found: {model_path}")
        
        model.to(self.device)
        model.eval()
        return model
    
    def _preprocess_image(self, image_path: str) -> torch.Tensor:
        """Preprocess a single image"""
        try:
            # load image
            image = Image.open(image_path)
            
            # apply transforms
            image_tensor = self.transform(image)
            
            # add batch dimension
            image_tensor = image_tensor.unsqueeze(0)  # (1, C, H, W)
            
            return image_tensor.to(self.device)
        
        except Exception as e:
            raise ValueError(f"Error processing image {image_path}: {str(e)}")
    
    def recognize(self, image_path: str, **kwargs) -> str:
        """
        Recognize shorthand from an image
        
        Args:
            image_path: Path to the image file
            **kwargs: Additional options for generation
        
        Returns:
            Recognized text string
        """
        # Preprocess image
        image_tensor = self._preprocess_image(image_path)
        
        with torch.no_grad():
            if self.model_type == "image_to_text":
                # image-to-text
                beam_size = kwargs.get('beam_size', 1)
                result = self.model.generate_text(image_tensor, beam_size=beam_size)
                return result if result else ""
            
            elif self.model_type == "seq2seq":
                # Sequence-to-sequence 
                return self._generate_seq2seq(image_tensor, **kwargs)
    
    def _generate_seq2seq(self, image_tensor: torch.Tensor, **kwargs) -> str:
        """Generate text using seq2seq model"""
        max_length = kwargs.get('max_length', 50)
        temperature = kwargs.get('temperature', 1.0)
        
        # Create character mappings 
        char_to_idx = {chr(i + ord('a')): i for i in range(26)}
        char_to_idx[' '] = 26
        char_to_idx['<END>'] = 27
        idx_to_char = {v: k for k, v in char_to_idx.items()}
        
        # Start with empty context
        context = torch.zeros(1, 1, dtype=torch.long, device=self.device)
        generated_text = ""
        
        for _ in range(max_length):
            # Get predictions
            predictions = self.model(image_tensor, context)
            
            # Get last prediction
            last_pred = predictions[:, -1, :]  # (1, vocab_size)
            
            # Apply temperature
            if temperature != 1.0:
                last_pred = last_pred / temperature
            
            # Sample next character
            probs = F.softmax(last_pred, dim=-1)
            next_char_idx = torch.multinomial(probs, 1).item()
            
            # Convert to character
            if next_char_idx in idx_to_char:
                char = idx_to_char[next_char_idx]
                if char == '<END>':
                    break
                generated_text += char
            
            # Update context
            next_char_tensor = torch.tensor([[next_char_idx]], device=self.device)
            context = torch.cat([context, next_char_tensor], dim=1)
        
        return generated_text
    
    def batch_recognize(self, image_paths: List[str], batch_size: int = 8, **kwargs) -> List[str]:
        """
        Recognize shorthand from several images
        
        Args:
            image_paths: List of image file paths
            batch_size: Batch size for processing
            **kwargs: Additional options for generation
        
        Returns:
            List of recognized text strings
        """
        results = []
        
        for i in range(0, len(image_paths), batch_size):
            batch_paths = image_paths[i:i + batch_size]
            batch_results = []
            
            for path in batch_paths:
                try:
                    result = self.recognize(path, **kwargs)
                    batch_results.append(result)
                except Exception as e:
                    print(f"Error processing {path}: {str(e)}")
                    batch_results.append("")
            
            results.extend(batch_results)
        
        return results
    
    def get_model_info(self) -> dict:
        """Get information about the loaded model"""
        num_params = sum(p.numel() for p in self.model.parameters())
        return {
            "model_type": self.model_type,
            "device": str(self.device),
            "num_parameters": num_params,
            "config": self.config.__dict__ if hasattr(self.config, '__dict__') else str(self.config)
        }