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rapidocr/python/rapidocr_openvino/ch_ppocr_rec/text_recognize.py
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# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import argparse
import math
import time
from pathlib import Path
from typing import List, Tuple, Union
import cv2
import numpy as np
from rapidocr_openvino.utils import OpenVINOInferSession, read_yaml
from .utils import CTCLabelDecode
DEFAULT_DICT_PATH = str(Path(__file__).parent / "ppocr_keys_v1.txt")
class TextRecognizer:
def __init__(self, config):
self.rec_image_shape = config["rec_img_shape"]
self.rec_batch_num = config["rec_batch_num"]
dict_path = config.get("rec_keys_path", None)
self.character_dict_path = dict_path if dict_path else DEFAULT_DICT_PATH
self.postprocess_op = CTCLabelDecode(character_path=self.character_dict_path)
self.session = OpenVINOInferSession(config)
def __call__(
self,
img_list: Union[np.ndarray, List[np.ndarray]],
return_word_box: bool = False,
) -> Tuple[List[Tuple[str, float]], float]:
if isinstance(img_list, np.ndarray):
img_list = [img_list]
# Calculate the aspect ratio of all text bars
width_list = [img.shape[1] / float(img.shape[0]) for img in img_list]
# Sorting can speed up the recognition process
indices = np.argsort(np.array(width_list))
img_num = len(img_list)
rec_res = [("", 0.0)] * img_num
batch_num = self.rec_batch_num
elapse = 0
for beg_img_no in range(0, img_num, batch_num):
end_img_no = min(img_num, beg_img_no + batch_num)
# Parameter Alignment for PaddleOCR
imgC, imgH, imgW = self.rec_image_shape[:3]
max_wh_ratio = imgW / imgH
wh_ratio_list = []
for ino in range(beg_img_no, end_img_no):
h, w = img_list[indices[ino]].shape[0:2]
wh_ratio = w * 1.0 / h
max_wh_ratio = max(max_wh_ratio, wh_ratio)
wh_ratio_list.append(wh_ratio)
norm_img_batch = []
for ino in range(beg_img_no, end_img_no):
norm_img = self.resize_norm_img(img_list[indices[ino]], max_wh_ratio)
norm_img_batch.append(norm_img[np.newaxis, :])
norm_img_batch = np.concatenate(norm_img_batch).astype(np.float32)
starttime = time.time()
preds = self.session(norm_img_batch)
rec_result = self.postprocess_op(
preds,
return_word_box,
wh_ratio_list=wh_ratio_list,
max_wh_ratio=max_wh_ratio,
)
for rno, one_res in enumerate(rec_result):
rec_res[indices[beg_img_no + rno]] = one_res
elapse += time.time() - starttime
return rec_res, elapse
def resize_norm_img(self, img: np.ndarray, max_wh_ratio: float) -> np.ndarray:
img_channel, img_height, img_width = self.rec_image_shape
assert img_channel == img.shape[2]
img_width = int(img_height * max_wh_ratio)
h, w = img.shape[:2]
ratio = w / float(h)
if math.ceil(img_height * ratio) > img_width:
resized_w = img_width
else:
resized_w = int(math.ceil(img_height * ratio))
resized_image = cv2.resize(img, (resized_w, img_height))
resized_image = resized_image.astype("float32")
resized_image = resized_image.transpose((2, 0, 1)) / 255
resized_image -= 0.5
resized_image /= 0.5
padding_im = np.zeros((img_channel, img_height, img_width), dtype=np.float32)
padding_im[:, :, 0:resized_w] = resized_image
return padding_im
if __name__ == "__main__":
parser = argparse.ArgumentParser()
parser.add_argument("--image_path", type=str, help="image_dir|image_path")
parser.add_argument("--config_path", type=str, default="config.yaml")
args = parser.parse_args()
config = read_yaml(args.config_path)
text_recognizer = TextRecognizer(config)
img = cv2.imread(args.image_path)
rec_res, predict_time = text_recognizer(img)
print(f"rec result: {rec_res}\t cost: {predict_time}s")