main.py

# -*- encoding: utf-8 -*-
# @Author: SWHL
# @Contact: liekkaskono@163.com
import copy
from pathlib import Path
from typing import Any, Dict, List, Optional, Tuple, Union

import cv2
import numpy as np

from .cal_rec_boxes import CalRecBoxes
from .ch_ppocr_cls import TextClassifier
from .ch_ppocr_det import TextDetector
from .ch_ppocr_rec import TextRecognizer
from .utils import (
    LoadImage,
    UpdateParameters,
    VisRes,
    add_round_letterbox,
    get_logger,
    increase_min_side,
    init_args,
    read_yaml,
    reduce_max_side,
    update_model_path,
)

root_dir = Path(__file__).resolve().parent
DEFAULT_CFG_PATH = root_dir / "config.yaml"
logger = get_logger("RapidOCR")


class RapidOCR:
    def __init__(self, config_path: Optional[str] = None, **kwargs):
        if config_path is not None and Path(config_path).exists():
            config = read_yaml(config_path)
        else:
            config = read_yaml(DEFAULT_CFG_PATH)
        config = update_model_path(config)

        if kwargs:
            updater = UpdateParameters()
            config = updater(config, **kwargs)

        global_config = config["Global"]
        self.print_verbose = global_config["print_verbose"]
        self.text_score = global_config["text_score"]
        self.min_height = global_config["min_height"]
        self.width_height_ratio = global_config["width_height_ratio"]

        self.use_det = global_config["use_det"]
        self.text_det = TextDetector(config["Det"])

        self.use_cls = global_config["use_cls"]
        self.text_cls = TextClassifier(config["Cls"])

        self.use_rec = global_config["use_rec"]
        self.text_rec = TextRecognizer(config["Rec"])

        self.load_img = LoadImage()
        self.max_side_len = global_config["max_side_len"]
        self.min_side_len = global_config["min_side_len"]

        self.cal_rec_boxes = CalRecBoxes()

    def __call__(
        self,
        img_content: Union[str, np.ndarray, bytes, Path],
        use_det: Optional[bool] = None,
        use_cls: Optional[bool] = None,
        use_rec: Optional[bool] = None,
        **kwargs,
    ) -> Tuple[Optional[List[List[Union[Any, str]]]], Optional[List[float]]]:
        use_det = self.use_det if use_det is None else use_det
        use_cls = self.use_cls if use_cls is None else use_cls
        use_rec = self.use_rec if use_rec is None else use_rec
        return_word_box = False
        if kwargs:
            box_thresh = kwargs.get("box_thresh", 0.5)
            unclip_ratio = kwargs.get("unclip_ratio", 1.6)
            text_score = kwargs.get("text_score", 0.5)
            return_word_box = kwargs.get("return_word_box", False)
            self.text_det.postprocess_op.box_thresh = box_thresh
            self.text_det.postprocess_op.unclip_ratio = unclip_ratio
            self.text_score = text_score

        img = self.load_img(img_content)

        raw_h, raw_w = img.shape[:2]
        op_record = {}
        img, ratio_h, ratio_w = self.preprocess(img)
        op_record["preprocess"] = {"ratio_h": ratio_h, "ratio_w": ratio_w}

        dt_boxes, cls_res, rec_res = None, None, None
        det_elapse, cls_elapse, rec_elapse = 0.0, 0.0, 0.0

        if use_det:
            img, op_record = self.maybe_add_letterbox(img, op_record)
            dt_boxes, det_elapse = self.auto_text_det(img)
            if dt_boxes is None:
                return None, None

            img = self.get_crop_img_list(img, dt_boxes)

        if use_cls:
            img, cls_res, cls_elapse = self.text_cls(img)

        if use_rec:
            rec_res, rec_elapse = self.text_rec(img, return_word_box)

        if dt_boxes is not None and rec_res is not None and return_word_box:
            rec_res = self.cal_rec_boxes(img, dt_boxes, rec_res)
            for rec_res_i in rec_res:
                if rec_res_i[2]:
                    rec_res_i[2] = (
                        self._get_origin_points(rec_res_i[2], op_record, raw_h, raw_w)
                        .astype(np.int32)
                        .tolist()
                    )

        if dt_boxes is not None:
            dt_boxes = self._get_origin_points(dt_boxes, op_record, raw_h, raw_w)

        ocr_res = self.get_final_res(
            dt_boxes, cls_res, rec_res, det_elapse, cls_elapse, rec_elapse
        )
        return ocr_res

    def preprocess(self, img: np.ndarray) -> Tuple[np.ndarray, float, float]:
        h, w = img.shape[:2]
        max_value = max(h, w)
        ratio_h = ratio_w = 1.0
        if max_value > self.max_side_len:
            img, ratio_h, ratio_w = reduce_max_side(img, self.max_side_len)

        h, w = img.shape[:2]
        min_value = min(h, w)
        if min_value < self.min_side_len:
            img, ratio_h, ratio_w = increase_min_side(img, self.min_side_len)
        return img, ratio_h, ratio_w

    def maybe_add_letterbox(
        self, img: np.ndarray, op_record: Dict[str, Any]
    ) -> Tuple[np.ndarray, Dict[str, Any]]:
        h, w = img.shape[:2]

        if self.width_height_ratio == -1:
            use_limit_ratio = False
        else:
            use_limit_ratio = w / h > self.width_height_ratio

        if h <= self.min_height or use_limit_ratio:
            padding_h = self._get_padding_h(h, w)
            block_img = add_round_letterbox(img, (padding_h, padding_h, 0, 0))
            op_record["padding_1"] = {"top": padding_h, "left": 0}
            return block_img, op_record

        op_record["padding_1"] = {"top": 0, "left": 0}
        return img, op_record

    def _get_padding_h(self, h: int, w: int) -> int:
        new_h = max(int(w / self.width_height_ratio), self.min_height) * 2
        padding_h = int(abs(new_h - h) / 2)
        return padding_h

    def auto_text_det(
        self, img: np.ndarray
    ) -> Tuple[Optional[List[np.ndarray]], float]:
        dt_boxes, det_elapse = self.text_det(img)
        if dt_boxes is None or len(dt_boxes) < 1:
            return None, 0.0

        dt_boxes = self.sorted_boxes(dt_boxes)
        return dt_boxes, det_elapse

    def get_crop_img_list(
        self, img: np.ndarray, dt_boxes: List[np.ndarray]
    ) -> List[np.ndarray]:
        def get_rotate_crop_image(img: np.ndarray, points: np.ndarray) -> np.ndarray:
            img_crop_width = int(
                max(
                    np.linalg.norm(points[0] - points[1]),
                    np.linalg.norm(points[2] - points[3]),
                )
            )
            img_crop_height = int(
                max(
                    np.linalg.norm(points[0] - points[3]),
                    np.linalg.norm(points[1] - points[2]),
                )
            )
            pts_std = np.array(
                [
                    [0, 0],
                    [img_crop_width, 0],
                    [img_crop_width, img_crop_height],
                    [0, img_crop_height],
                ]
            ).astype(np.float32)
            M = cv2.getPerspectiveTransform(points, pts_std)
            dst_img = cv2.warpPerspective(
                img,
                M,
                (img_crop_width, img_crop_height),
                borderMode=cv2.BORDER_REPLICATE,
                flags=cv2.INTER_CUBIC,
            )
            dst_img_height, dst_img_width = dst_img.shape[0:2]
            if dst_img_height * 1.0 / dst_img_width >= 1.5:
                dst_img = np.rot90(dst_img)
            return dst_img

        img_crop_list = []
        for box in dt_boxes:
            tmp_box = copy.deepcopy(box)
            img_crop = get_rotate_crop_image(img, tmp_box)
            img_crop_list.append(img_crop)
        return img_crop_list

    @staticmethod
    def sorted_boxes(dt_boxes: np.ndarray) -> List[np.ndarray]:
        """
        Sort text boxes in order from top to bottom, left to right
        args:
            dt_boxes(array):detected text boxes with shape [4, 2]
        return:
            sorted boxes(array) with shape [4, 2]
        """
        num_boxes = dt_boxes.shape[0]
        sorted_boxes = sorted(dt_boxes, key=lambda x: (x[0][1], x[0][0]))
        _boxes = list(sorted_boxes)

        for i in range(num_boxes - 1):
            for j in range(i, -1, -1):
                if (
                    abs(_boxes[j + 1][0][1] - _boxes[j][0][1]) < 10
                    and _boxes[j + 1][0][0] < _boxes[j][0][0]
                ):
                    tmp = _boxes[j]
                    _boxes[j] = _boxes[j + 1]
                    _boxes[j + 1] = tmp
                else:
                    break
        return _boxes

    def _get_origin_points(
        self,
        dt_boxes: List[np.ndarray],
        op_record: Dict[str, Any],
        raw_h: int,
        raw_w: int,
    ) -> np.ndarray:
        dt_boxes_array = np.array(dt_boxes).astype(np.float32)
        for op in reversed(list(op_record.keys())):
            v = op_record[op]
            if "padding" in op:
                top, left = v.get("top"), v.get("left")
                dt_boxes_array[:, :, 0] -= left
                dt_boxes_array[:, :, 1] -= top
            elif "preprocess" in op:
                ratio_h = v.get("ratio_h")
                ratio_w = v.get("ratio_w")
                dt_boxes_array[:, :, 0] *= ratio_w
                dt_boxes_array[:, :, 1] *= ratio_h

        dt_boxes_array = np.where(dt_boxes_array < 0, 0, dt_boxes_array)
        dt_boxes_array[..., 0] = np.where(
            dt_boxes_array[..., 0] > raw_w, raw_w, dt_boxes_array[..., 0]
        )
        dt_boxes_array[..., 1] = np.where(
            dt_boxes_array[..., 1] > raw_h, raw_h, dt_boxes_array[..., 1]
        )
        return dt_boxes_array

    def get_final_res(
        self,
        dt_boxes: Optional[List[np.ndarray]],
        cls_res: Optional[List[List[Union[str, float]]]],
        rec_res: Optional[List[Tuple[str, float, List[Union[str, float]]]]],
        det_elapse: float,
        cls_elapse: float,
        rec_elapse: float,
    ) -> Tuple[Optional[List[List[Union[Any, str]]]], Optional[List[float]]]:
        if dt_boxes is None and rec_res is None and cls_res is not None:
            return cls_res, [cls_elapse]

        if dt_boxes is None and rec_res is None:
            return None, None

        if dt_boxes is None and rec_res is not None:
            return [[res[0], res[1]] for res in rec_res], [rec_elapse]

        if dt_boxes is not None and rec_res is None:
            return [box.tolist() for box in dt_boxes], [det_elapse]

        dt_boxes, rec_res = self.filter_result(dt_boxes, rec_res)
        if not dt_boxes or not rec_res or len(dt_boxes) <= 0:
            return None, None

        ocr_res = [[box.tolist(), *res] for box, res in zip(dt_boxes, rec_res)], [
            det_elapse,
            cls_elapse,
            rec_elapse,
        ]
        return ocr_res

    def filter_result(
        self,
        dt_boxes: Optional[List[np.ndarray]],
        rec_res: Optional[List[Tuple[str, float]]],
    ) -> Tuple[Optional[List[np.ndarray]], Optional[List[Tuple[str, float]]]]:
        if dt_boxes is None or rec_res is None:
            return None, None

        filter_boxes, filter_rec_res = [], []
        for box, rec_reuslt in zip(dt_boxes, rec_res):
            text, score = rec_reuslt[0], rec_reuslt[1]
            if float(score) >= self.text_score:
                filter_boxes.append(box)
                filter_rec_res.append(rec_reuslt)

        return filter_boxes, filter_rec_res


def main():
    args = init_args()
    ocr_engine = RapidOCR(**vars(args))

    use_det = not args.no_det
    use_cls = not args.no_cls
    use_rec = not args.no_rec
    result, elapse_list = ocr_engine(
        args.img_path,
        use_det=use_det,
        use_cls=use_cls,
        use_rec=use_rec,
        **vars(args)
    )
    logger.info(result)

    if args.print_cost:
        logger.info(elapse_list)

    if args.vis_res:
        vis = VisRes()
        Path(args.vis_save_path).mkdir(parents=True, exist_ok=True)
        save_path = Path(args.vis_save_path) / f"{Path(args.img_path).stem}_vis.png"

        if use_det and not use_cls and not use_rec:
            boxes, *_ = list(zip(*result))
            vis_img = vis(args.img_path, boxes)
            cv2.imwrite(str(save_path), vis_img)
            logger.info("The vis result has saved in %s", save_path)

        elif use_det and use_rec:
            font_path = Path(args.vis_font_path)
            if not font_path.exists():
                raise FileExistsError(f"{font_path} does not exist!")

            boxes, txts, scores = list(zip(*result))
            vis_img = vis(args.img_path, boxes, txts, scores, font_path=font_path)
            cv2.imwrite(str(save_path), vis_img)
            logger.info("The vis result has saved in %s", save_path)


if __name__ == "__main__":
    main()