|
| 1 | +import math |
| 2 | +import os |
| 3 | + |
| 4 | +import cv2 |
| 5 | +import numpy as np |
| 6 | +import onnxruntime as ort |
| 7 | +from module.exception import RequestHumanTakeover |
| 8 | +from module.logger import logger |
| 9 | + |
| 10 | +logger.info('Loading PP-OCR dependencies') |
| 11 | + |
| 12 | + |
| 13 | +class PpOcr: |
| 14 | + # cpu only |
| 15 | + |
| 16 | + def __init__( |
| 17 | + self, |
| 18 | + model_name='ppocrv5', |
| 19 | + cand_alphabet=None, |
| 20 | + root='./bin/ppocr_models/ppocrv5', |
| 21 | + name=None, |
| 22 | + ): |
| 23 | + self._args = (model_name, cand_alphabet, root, name) |
| 24 | + self._model_loaded = False |
| 25 | + |
| 26 | + def init( |
| 27 | + self, |
| 28 | + model_name='ppocrv5', |
| 29 | + cand_alphabet=None, |
| 30 | + root='./bin/ppocr_models', |
| 31 | + name=None, |
| 32 | + ): |
| 33 | + """ |
| 34 | + :param model_name: 模型名称 |
| 35 | + :param cand_alphabet: 待识别字符所在的候选集合。默认为 `None`,表示不限定识别字符范围 |
| 36 | + :param root: 模型文件所在的根目录 |
| 37 | + :param name: 正在初始化的这个实例名称。如果需要同时初始化多个实例,需要为不同的实例指定不同的名称。 |
| 38 | + """ |
| 39 | + self._model_name = model_name |
| 40 | + self._model_dir = root |
| 41 | + |
| 42 | + self._assert_and_prepare_model_files() |
| 43 | + self._alphabet = self._read_charset( |
| 44 | + os.path.join(self._model_dir, 'label.txt') |
| 45 | + ) |
| 46 | + |
| 47 | + # Alphabet will be set before calling ocr. |
| 48 | + # self.set_cand_alphabet(cand_alphabet) |
| 49 | + self._cand_alphabet = None |
| 50 | + |
| 51 | + # Load model |
| 52 | + self._det_model = ort.InferenceSession(os.path.join(self._model_dir, 'det.onnx')) |
| 53 | + self._rec_model = ort.InferenceSession(os.path.join(self._model_dir, 'rec.onnx')) |
| 54 | + |
| 55 | + def ocr(self, img, detect=True): |
| 56 | + """ |
| 57 | + Only support one line OCR |
| 58 | +
|
| 59 | + :param img: image file path; or color image np.ndarray, |
| 60 | + with shape (height, width, 3), and the channels should be RGB formatted. |
| 61 | + :param detect: If true, detect the text region for recognization. Default: True. |
| 62 | + :return: List(Char), such as: |
| 63 | + ['第', '一', '行'] |
| 64 | + """ |
| 65 | + if not self._model_loaded: |
| 66 | + self.init(*self._args) |
| 67 | + self._model_loaded = True |
| 68 | + |
| 69 | + img = self._load_image(img) |
| 70 | + |
| 71 | + if detect: |
| 72 | + image = self._preprocess_image(img, 'det') |
| 73 | + boxes = self._detect(image) |
| 74 | + if boxes: |
| 75 | + boxes.sort(key=lambda box: box[2], reverse=True) |
| 76 | + x, y, w, h = boxes[0] |
| 77 | + image = img[y:y + h, x:x + w] |
| 78 | + else: |
| 79 | + image = img |
| 80 | + |
| 81 | + image = self._preprocess_image(image) |
| 82 | + preds = self._predict(image) |
| 83 | + result = self._postprocess_text(preds)[0] |
| 84 | + return result |
| 85 | + |
| 86 | + def atomic_ocr_for_single_lines(self, img_list, cand_alphabet=None, batch_size=10, batch_threshold=20, detect=True): |
| 87 | + """ |
| 88 | + Multi images, one line OCR |
| 89 | + """ |
| 90 | + if len(img_list) == 0: |
| 91 | + return [] |
| 92 | + |
| 93 | + if not self._model_loaded: |
| 94 | + self.init(*self._args) |
| 95 | + self._model_loaded = True |
| 96 | + |
| 97 | + self.set_cand_alphabet(cand_alphabet) |
| 98 | + |
| 99 | + results = [] |
| 100 | + |
| 101 | + if detect: |
| 102 | + image_list = [self._load_image(img) for img in img_list] |
| 103 | + image_list = [self._preprocess_image(img, 'det') for img in image_list] |
| 104 | + for i, img in enumerate(image_list): |
| 105 | + boxes = self._detect(img) |
| 106 | + if boxes: |
| 107 | + boxes.sort(key=lambda box: box[2], reverse=True) |
| 108 | + x, y, w, h = boxes[0] |
| 109 | + image_list[i] = img_list[i][y:y + h, x:x + w] |
| 110 | + else: |
| 111 | + image_list[i] = img_list[i] |
| 112 | + img_list = image_list |
| 113 | + |
| 114 | + for batch in self._batch_imgs(img_list, batch_size, batch_threshold): |
| 115 | + preds = self._predict(batch) |
| 116 | + results.extend(self._postprocess_text(preds)) |
| 117 | + |
| 118 | + return results |
| 119 | + |
| 120 | + def detect_then_ocr(self, img, pad=10, threshold=0.6, mode=cv2.RETR_EXTERNAL, batch_size=10, batch_threshold=20, |
| 121 | + debug=False): |
| 122 | + """ |
| 123 | + Detect potential text regions and perform OCR. |
| 124 | + The order of detected text is not guaranteed. |
| 125 | +
|
| 126 | + :param img: image file path; or color image np.ndarray, |
| 127 | + with shape (height, width, 3), and the channels should be RGB formatted. |
| 128 | + :param pad: pad detected text region, both width and height. |
| 129 | + :param threshold: threshold for detect text. |
| 130 | + :param mode: cv2.findCounters(), one of [RETR_EXTERNAL, RETR_LIST, RETR_CCOMP, RETR_TREE, RETR_FLOODFILL]. |
| 131 | + :param batch_size: the batch size of text recognition. |
| 132 | + :param batch_threshold: images with width differences less than or equal to batch_threshold are placed in the same batch, |
| 133 | + ensuring similar dimensions within a batch and improving memory and computational efficiency. |
| 134 | + :param debug: debug mode. |
| 135 | + :return: A tuple containing two lists: |
| 136 | + the recognized text and its corresponding region (x, y, w, h). |
| 137 | + """ |
| 138 | + if not self._model_loaded: |
| 139 | + self.init(*self._args) |
| 140 | + self._model_loaded = True |
| 141 | + |
| 142 | + img = self._load_image(img) |
| 143 | + image = img |
| 144 | + image = self._preprocess_image(image, 'det') |
| 145 | + boxes = self._detect(image, pad, threshold, mode) |
| 146 | + boxes.sort(key=lambda box: box[2]) |
| 147 | + |
| 148 | + crops, regions = [], [] |
| 149 | + for box in boxes: |
| 150 | + x, y, w, h = box |
| 151 | + crop = img[y:y + h, x:x + w, :] |
| 152 | + crops.append(crop) |
| 153 | + |
| 154 | + texts, index = [], 0 |
| 155 | + for batch in self._batch_imgs(crops, batch_size, batch_threshold): |
| 156 | + preds = self._predict(batch) |
| 157 | + batch_text = self._postprocess_text(preds) |
| 158 | + for chars in batch_text: |
| 159 | + text = ''.join([c.strip() for c in chars]) |
| 160 | + if text: |
| 161 | + texts.append(text) |
| 162 | + regions.append(boxes[index]) |
| 163 | + |
| 164 | + if debug: |
| 165 | + x, y, w, h = boxes[index] |
| 166 | + logger.info(f'[OCR] Text: {text}, Region: ({x}, {y}), ({x + w}, {y + h})') |
| 167 | + tmp = cv2.rectangle(img.copy(), (x, y), (x + w, y + h), (255, 0, 0), 2) |
| 168 | + cv2.imshow("ppocr", cv2.cvtColor(tmp, cv2.COLOR_RGB2BGR)) |
| 169 | + cv2.waitKey(0) |
| 170 | + |
| 171 | + index += 1 |
| 172 | + |
| 173 | + return texts, regions |
| 174 | + |
| 175 | + def set_cand_alphabet(self, cand_alphabet): |
| 176 | + self._cand_alphabet = [c for c in cand_alphabet] if cand_alphabet else None |
| 177 | + |
| 178 | + def _assert_and_prepare_model_files(self): |
| 179 | + model_dir = self._model_dir |
| 180 | + model_files = [ |
| 181 | + 'label.txt', |
| 182 | + 'det.onnx', |
| 183 | + 'rec.onnx' |
| 184 | + ] |
| 185 | + file_prepared = True |
| 186 | + for f in model_files: |
| 187 | + f = os.path.join(model_dir, f) |
| 188 | + if not os.path.exists(f): |
| 189 | + file_prepared = False |
| 190 | + logger.warning('can not find file %s', f) |
| 191 | + break |
| 192 | + |
| 193 | + if file_prepared: |
| 194 | + return |
| 195 | + |
| 196 | + logger.warning(f'Ocr model not prepared: {model_dir}') |
| 197 | + logger.warning(f'Required files: {model_files}') |
| 198 | + logger.critical('Please check if required files of pre-trained OCR model exist') |
| 199 | + raise RequestHumanTakeover |
| 200 | + |
| 201 | + def _read_charset(self, filename): |
| 202 | + with open(filename, encoding='utf-8') as f: |
| 203 | + alphabet = [line.rstrip('\n') for line in f.readlines()] |
| 204 | + alphabet.append('') |
| 205 | + return np.array(alphabet) |
| 206 | + |
| 207 | + def _load_image(self, img): |
| 208 | + if isinstance(img, str): |
| 209 | + if not os.path.isfile(img): |
| 210 | + raise FileNotFoundError |
| 211 | + img = cv2.imread(img) |
| 212 | + img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB) |
| 213 | + elif isinstance(img, np.ndarray): |
| 214 | + img = img |
| 215 | + elif isinstance(img, list): |
| 216 | + img = np.array(img[0]) |
| 217 | + else: |
| 218 | + raise TypeError |
| 219 | + return img |
| 220 | + |
| 221 | + def _preprocess_image(self, img, resize_mode='rec'): |
| 222 | + if len(img.shape) == 2: |
| 223 | + img = cv2.cvtColor(img, cv2.COLOR_GRAY2RGB) |
| 224 | + |
| 225 | + if resize_mode == 'rec': |
| 226 | + if img.shape[0] > img.shape[1] * 1.5: |
| 227 | + img = cv2.rotate(img, cv2.ROTATE_90_COUNTERCLOCKWISE) |
| 228 | + |
| 229 | + # Image's height must be 48 |
| 230 | + scale = 48 / img.shape[0] |
| 231 | + new_w = int(img.shape[1] * scale) |
| 232 | + img = cv2.resize(img, (new_w, 48)) |
| 233 | + |
| 234 | + elif resize_mode == 'det': |
| 235 | + pad_h = math.ceil(img.shape[0] / 32) * 32 - img.shape[0] |
| 236 | + pad_w = math.ceil(img.shape[1] / 32) * 32 - img.shape[1] |
| 237 | + img = np.pad(img, ((0, pad_h), (0, pad_w), (0, 0)), mode='constant') |
| 238 | + |
| 239 | + img = np.transpose(img, (2, 0, 1)) |
| 240 | + img = np.expand_dims(img, axis=0) |
| 241 | + img = img.astype('float32') / 255.0 |
| 242 | + img = (img - 0.5) / 0.5 |
| 243 | + return img |
| 244 | + |
| 245 | + def _batch_imgs(self, imgs, batch_size=None, batch_threshold=20): |
| 246 | + def pad_img(): |
| 247 | + batch_padded = [] |
| 248 | + for b in batch: |
| 249 | + padded = np.pad(b, ((0, 0), (0, 0), (0, 0), (0, max_width - b.shape[3])), mode='constant') |
| 250 | + batch_padded.append(padded) |
| 251 | + return np.vstack(batch_padded) |
| 252 | + |
| 253 | + batch = [] |
| 254 | + min_width, max_width = 1280, 0 |
| 255 | + for img in imgs: |
| 256 | + img = self._load_image(img) |
| 257 | + img = self._preprocess_image(img) |
| 258 | + |
| 259 | + min_width = min(min_width, img.shape[3]) |
| 260 | + max_width = max(max_width, img.shape[3]) |
| 261 | + |
| 262 | + if isinstance(batch_threshold, int) and max_width - min_width > batch_threshold: |
| 263 | + yield pad_img() |
| 264 | + batch = [] |
| 265 | + min_width, max_width = img.shape[3], img.shape[3] |
| 266 | + |
| 267 | + batch.append(img) |
| 268 | + |
| 269 | + if len(batch) == batch_size: |
| 270 | + yield pad_img() |
| 271 | + batch = [] |
| 272 | + min_width, max_width = 1280, 0 |
| 273 | + |
| 274 | + if batch: |
| 275 | + yield pad_img() |
| 276 | + |
| 277 | + def _detect(self, img, pad=10, threshold=0.3, mode=cv2.RETR_EXTERNAL): |
| 278 | + input_name = self._det_model.get_inputs()[0].name |
| 279 | + preds = self._det_model.run(None, {input_name: img})[0][0, 0] |
| 280 | + score_map = (preds > threshold).astype(np.uint8) * 255 |
| 281 | + contours, _ = cv2.findContours(score_map, mode, cv2.CHAIN_APPROX_SIMPLE) |
| 282 | + boxes = [self._expand_rect(cv2.boundingRect(cnt), img.shape, pad) for cnt in contours] |
| 283 | + return boxes |
| 284 | + |
| 285 | + def _expand_rect(self, rect, img_shape, pad=10): |
| 286 | + x, y, w, h = rect |
| 287 | + w, h = min(img_shape[3] - 1, w + pad), min(img_shape[2] - 1, h + pad) |
| 288 | + x, y = max(0, x - pad // 2), max(0, y - pad // 2) |
| 289 | + return x, y, w, h |
| 290 | + |
| 291 | + def _predict(self, img): |
| 292 | + input_name = self._rec_model.get_inputs()[0].name |
| 293 | + preds = self._rec_model.run(None, {input_name: img})[0] |
| 294 | + preds = preds.argmax(axis=2) - 1 |
| 295 | + return preds |
| 296 | + |
| 297 | + def _postprocess_text(self, preds): |
| 298 | + if len(preds.shape) == 1: |
| 299 | + preds = np.expand_dims(preds, 0) |
| 300 | + |
| 301 | + result = [] |
| 302 | + for pred in preds: |
| 303 | + chars = self._alphabet[pred] |
| 304 | + if self._cand_alphabet: |
| 305 | + mask = np.isin(chars, self._cand_alphabet) |
| 306 | + chars = chars[mask] |
| 307 | + result.append(chars) |
| 308 | + |
| 309 | + return result |
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