ocr/recognizer.py

import os
import sys

from PIL import Image

__dir__ = os.path.dirname(os.path.abspath(__file__))
sys.path.append(__dir__)
sys.path.insert(0, os.path.abspath(os.path.join(__dir__, "../..")))

os.environ["FLAGS_allocator_strategy"] = "auto_growth"

import math
import time

import cv2
import numpy as np

import utility
from postprocess import build_post_process


def _check_image_file(path):
    img_end = {"jpg", "bmp", "png", "jpeg", "rgb", "tif", "tiff", "gif"}
    return any([path.lower().endswith(e) for e in img_end])


def get_image_file_list(img_file):
    imgs_lists = []
    if img_file is None or not os.path.exists(img_file):
        raise Exception("not found any img file in {}".format(img_file))

    img_end = {"jpg", "bmp", "png", "jpeg", "rgb", "tif", "tiff", "gif"}
    if os.path.isfile(img_file) and _check_image_file(img_file):
        imgs_lists.append(img_file)
    elif os.path.isdir(img_file):
        for single_file in os.listdir(img_file):
            file_path = os.path.join(img_file, single_file)
            if os.path.isfile(file_path) and _check_image_file(file_path):
                imgs_lists.append(file_path)
    if len(imgs_lists) == 0:
        raise Exception("not found any img file in {}".format(img_file))
    imgs_lists = sorted(imgs_lists)
    return imgs_lists


def check_and_read_gif(img_path):
    if os.path.basename(img_path)[-3:] in ["gif", "GIF"]:
        gif = cv2.VideoCapture(img_path)
        ret, frame = gif.read()
        if not ret:
            return None, False
        if len(frame.shape) == 2 or frame.shape[-1] == 1:
            frame = cv2.cvtColor(frame, cv2.COLOR_GRAY2RGB)
        imgvalue = frame[:, :, ::-1]
        return imgvalue, True
    return None, False


class TextRecognizer(object):
    def __init__(self, args):
        self.rec_image_shape = [int(v) for v in args.rec_image_shape.split(",")]
        self.rec_batch_num = args.rec_batch_num
        self.rec_algorithm = args.rec_algorithm
        postprocess_params = {
            "name": "CTCLabelDecode",
            "character_dict_path": args.rec_char_dict_path,
            "use_space_char": args.use_space_char,
        }
        if self.rec_algorithm == "SRN":
            postprocess_params = {
                "name": "SRNLabelDecode",
                "character_dict_path": args.rec_char_dict_path,
                "use_space_char": args.use_space_char,
            }
        elif self.rec_algorithm == "RARE":
            postprocess_params = {
                "name": "AttnLabelDecode",
                "character_dict_path": args.rec_char_dict_path,
                "use_space_char": args.use_space_char,
            }
        elif self.rec_algorithm == "NRTR":
            postprocess_params = {
                "name": "NRTRLabelDecode",
                "character_dict_path": args.rec_char_dict_path,
                "use_space_char": args.use_space_char,
            }
        elif self.rec_algorithm == "SAR":
            postprocess_params = {
                "name": "SARLabelDecode",
                "character_dict_path": args.rec_char_dict_path,
                "use_space_char": args.use_space_char,
            }
        self.postprocess_op = build_post_process(postprocess_params)
        (
            self.predictor,
            self.input_tensor,
            self.output_tensors,
            self.config,
        ) = utility.create_predictor(args, "rec")
        self.use_onnx = args.use_onnx

    def resize_norm_img(self, img, max_wh_ratio):
        imgC, imgH, imgW = self.rec_image_shape
        if self.rec_algorithm == "NRTR":
            img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
            # return padding_im
            image_pil = Image.fromarray(np.uint8(img))
            img = image_pil.resize([100, 32], Image.ANTIALIAS)
            img = np.array(img)
            norm_img = np.expand_dims(img, -1)
            norm_img = norm_img.transpose((2, 0, 1))
            return norm_img.astype(np.float32) / 128.0 - 1.0

        assert imgC == img.shape[2]
        imgW = int((imgH * max_wh_ratio))
        if self.use_onnx:
            w = self.input_tensor.shape[3:][0]
            if w is not None and w > 0:
                imgW = w

        h, w = img.shape[:2]
        ratio = w / float(h)
        if math.ceil(imgH * ratio) > imgW:
            resized_w = imgW
        else:
            resized_w = int(math.ceil(imgH * ratio))
        if self.rec_algorithm == "RARE":
            if resized_w > self.rec_image_shape[2]:
                resized_w = self.rec_image_shape[2]
            imgW = self.rec_image_shape[2]
        resized_image = cv2.resize(img, (resized_w, imgH))
        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((imgC, imgH, imgW), dtype=np.float32)
        padding_im[:, :, 0:resized_w] = resized_image
        return padding_im

    def resize_norm_img_svtr(self, img, image_shape):

        imgC, imgH, imgW = image_shape
        resized_image = cv2.resize(img, (imgW, imgH), interpolation=cv2.INTER_LINEAR)
        resized_image = resized_image.astype("float32")
        resized_image = resized_image.transpose((2, 0, 1)) / 255
        resized_image -= 0.5
        resized_image /= 0.5
        return resized_image

    def resize_norm_img_srn(self, img, image_shape):
        imgC, imgH, imgW = image_shape

        img_black = np.zeros((imgH, imgW))
        im_hei = img.shape[0]
        im_wid = img.shape[1]

        if im_wid <= im_hei * 1:
            img_new = cv2.resize(img, (imgH * 1, imgH))
        elif im_wid <= im_hei * 2:
            img_new = cv2.resize(img, (imgH * 2, imgH))
        elif im_wid <= im_hei * 3:
            img_new = cv2.resize(img, (imgH * 3, imgH))
        else:
            img_new = cv2.resize(img, (imgW, imgH))

        img_np = np.asarray(img_new)
        img_np = cv2.cvtColor(img_np, cv2.COLOR_BGR2GRAY)
        img_black[:, 0 : img_np.shape[1]] = img_np
        img_black = img_black[:, :, np.newaxis]

        row, col, c = img_black.shape
        c = 1

        return np.reshape(img_black, (c, row, col)).astype(np.float32)

    def srn_other_inputs(self, image_shape, num_heads, max_text_length):

        imgC, imgH, imgW = image_shape
        feature_dim = int((imgH / 8) * (imgW / 8))

        encoder_word_pos = (
            np.array(range(0, feature_dim)).reshape((feature_dim, 1)).astype("int64")
        )
        gsrm_word_pos = (
            np.array(range(0, max_text_length))
            .reshape((max_text_length, 1))
            .astype("int64")
        )

        gsrm_attn_bias_data = np.ones((1, max_text_length, max_text_length))
        gsrm_slf_attn_bias1 = np.triu(gsrm_attn_bias_data, 1).reshape(
            [-1, 1, max_text_length, max_text_length]
        )
        gsrm_slf_attn_bias1 = np.tile(gsrm_slf_attn_bias1, [1, num_heads, 1, 1]).astype(
            "float32"
        ) * [-1e9]

        gsrm_slf_attn_bias2 = np.tril(gsrm_attn_bias_data, -1).reshape(
            [-1, 1, max_text_length, max_text_length]
        )
        gsrm_slf_attn_bias2 = np.tile(gsrm_slf_attn_bias2, [1, num_heads, 1, 1]).astype(
            "float32"
        ) * [-1e9]

        encoder_word_pos = encoder_word_pos[np.newaxis, :]
        gsrm_word_pos = gsrm_word_pos[np.newaxis, :]

        return [
            encoder_word_pos,
            gsrm_word_pos,
            gsrm_slf_attn_bias1,
            gsrm_slf_attn_bias2,
        ]

    def process_image_srn(self, img, image_shape, num_heads, max_text_length):
        norm_img = self.resize_norm_img_srn(img, image_shape)
        norm_img = norm_img[np.newaxis, :]

        [
            encoder_word_pos,
            gsrm_word_pos,
            gsrm_slf_attn_bias1,
            gsrm_slf_attn_bias2,
        ] = self.srn_other_inputs(image_shape, num_heads, max_text_length)

        gsrm_slf_attn_bias1 = gsrm_slf_attn_bias1.astype(np.float32)
        gsrm_slf_attn_bias2 = gsrm_slf_attn_bias2.astype(np.float32)
        encoder_word_pos = encoder_word_pos.astype(np.int64)
        gsrm_word_pos = gsrm_word_pos.astype(np.int64)

        return (
            norm_img,
            encoder_word_pos,
            gsrm_word_pos,
            gsrm_slf_attn_bias1,
            gsrm_slf_attn_bias2,
        )

    def resize_norm_img_sar(self, img, image_shape, width_downsample_ratio=0.25):
        imgC, imgH, imgW_min, imgW_max = image_shape
        h = img.shape[0]
        w = img.shape[1]
        valid_ratio = 1.0
        # make sure new_width is an integral multiple of width_divisor.
        width_divisor = int(1 / width_downsample_ratio)
        # resize
        ratio = w / float(h)
        resize_w = math.ceil(imgH * ratio)
        if resize_w % width_divisor != 0:
            resize_w = round(resize_w / width_divisor) * width_divisor
        if imgW_min is not None:
            resize_w = max(imgW_min, resize_w)
        if imgW_max is not None:
            valid_ratio = min(1.0, 1.0 * resize_w / imgW_max)
            resize_w = min(imgW_max, resize_w)
        resized_image = cv2.resize(img, (resize_w, imgH))
        resized_image = resized_image.astype("float32")
        # norm
        if image_shape[0] == 1:
            resized_image = resized_image / 255
            resized_image = resized_image[np.newaxis, :]
        else:
            resized_image = resized_image.transpose((2, 0, 1)) / 255
        resized_image -= 0.5
        resized_image /= 0.5
        resize_shape = resized_image.shape
        padding_im = -1.0 * np.ones((imgC, imgH, imgW_max), dtype=np.float32)
        padding_im[:, :, 0:resize_w] = resized_image
        pad_shape = padding_im.shape

        return padding_im, resize_shape, pad_shape, valid_ratio

    def __call__(self, img_list):
        img_num = len(img_list)
        # Calculate the aspect ratio of all text bars
        width_list = []
        for img in img_list:
            width_list.append(img.shape[1] / float(img.shape[0]))
        # Sorting can speed up the recognition process
        indices = np.argsort(np.array(width_list))
        rec_res = [["", 0.0]] * img_num
        batch_num = self.rec_batch_num
        st = time.time()
        for beg_img_no in range(0, img_num, batch_num):
            end_img_no = min(img_num, beg_img_no + batch_num)
            norm_img_batch = []
            imgC, imgH, imgW = self.rec_image_shape
            max_wh_ratio = imgW / imgH
            # max_wh_ratio = 0
            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)
            for ino in range(beg_img_no, end_img_no):

                if self.rec_algorithm == "SAR":
                    norm_img, _, _, valid_ratio = self.resize_norm_img_sar(
                        img_list[indices[ino]], self.rec_image_shape
                    )
                    norm_img = norm_img[np.newaxis, :]
                    valid_ratio = np.expand_dims(valid_ratio, axis=0)
                    valid_ratios = []
                    valid_ratios.append(valid_ratio)
                    norm_img_batch.append(norm_img)
                elif self.rec_algorithm == "SRN":
                    norm_img = self.process_image_srn(
                        img_list[indices[ino]], self.rec_image_shape, 8, 25
                    )
                    encoder_word_pos_list = []
                    gsrm_word_pos_list = []
                    gsrm_slf_attn_bias1_list = []
                    gsrm_slf_attn_bias2_list = []
                    encoder_word_pos_list.append(norm_img[1])
                    gsrm_word_pos_list.append(norm_img[2])
                    gsrm_slf_attn_bias1_list.append(norm_img[3])
                    gsrm_slf_attn_bias2_list.append(norm_img[4])
                    norm_img_batch.append(norm_img[0])
                elif self.rec_algorithm == "SVTR":
                    norm_img = self.resize_norm_img_svtr(
                        img_list[indices[ino]], self.rec_image_shape
                    )
                    norm_img = norm_img[np.newaxis, :]
                    norm_img_batch.append(norm_img)
                else:
                    norm_img = self.resize_norm_img(
                        img_list[indices[ino]], max_wh_ratio
                    )
                    norm_img = norm_img[np.newaxis, :]
                    norm_img_batch.append(norm_img)
            norm_img_batch = np.concatenate(norm_img_batch)
            norm_img_batch = norm_img_batch.copy()

            if self.rec_algorithm == "SRN":
                encoder_word_pos_list = np.concatenate(encoder_word_pos_list)
                gsrm_word_pos_list = np.concatenate(gsrm_word_pos_list)
                gsrm_slf_attn_bias1_list = np.concatenate(gsrm_slf_attn_bias1_list)
                gsrm_slf_attn_bias2_list = np.concatenate(gsrm_slf_attn_bias2_list)

                inputs = [
                    norm_img_batch,
                    encoder_word_pos_list,
                    gsrm_word_pos_list,
                    gsrm_slf_attn_bias1_list,
                    gsrm_slf_attn_bias2_list,
                ]
                if self.use_onnx:
                    input_dict = {}
                    input_dict[self.input_tensor.name] = norm_img_batch
                    outputs = self.predictor.run(self.output_tensors, input_dict)
                    preds = {"predict": outputs[2]}
                else:
                    input_names = self.predictor.get_input_names()
                    for i in range(len(input_names)):
                        input_tensor = self.predictor.get_input_handle(input_names[i])
                        input_tensor.copy_from_cpu(inputs[i])
                    self.predictor.run()
                    outputs = []
                    for output_tensor in self.output_tensors:
                        output = output_tensor.copy_to_cpu()
                        outputs.append(output)
                    preds = {"predict": outputs[2]}
            elif self.rec_algorithm == "SAR":
                valid_ratios = np.concatenate(valid_ratios)
                inputs = [
                    norm_img_batch,
                    valid_ratios,
                ]
                if self.use_onnx:
                    input_dict = {}
                    input_dict[self.input_tensor.name] = norm_img_batch
                    outputs = self.predictor.run(self.output_tensors, input_dict)
                    preds = outputs[0]
                else:
                    input_names = self.predictor.get_input_names()
                    for i in range(len(input_names)):
                        input_tensor = self.predictor.get_input_handle(input_names[i])
                        input_tensor.copy_from_cpu(inputs[i])
                    self.predictor.run()
                    outputs = []
                    for output_tensor in self.output_tensors:
                        output = output_tensor.copy_to_cpu()
                        outputs.append(output)
                    preds = outputs[0]
            else:
                if self.use_onnx:
                    input_dict = {}
                    input_dict[self.input_tensor.name] = norm_img_batch
                    outputs = self.predictor.run(self.output_tensors, input_dict)
                    preds = outputs[0]
                else:
                    self.input_tensor.copy_from_cpu(norm_img_batch)
                    self.predictor.run()
                    outputs = []
                    for output_tensor in self.output_tensors:
                        output = output_tensor.copy_to_cpu()
                        outputs.append(output)
                    if len(outputs) != 1:
                        preds = outputs
                    else:
                        preds = outputs[0]
            rec_result = self.postprocess_op(preds)
            for rno in range(len(rec_result)):
                rec_res[indices[beg_img_no + rno]] = rec_result[rno]
        return rec_res, time.time() - st


def main(args):
    image_file_list = get_image_file_list(args.image_dir)
    text_recognizer = TextRecognizer(args)
    valid_image_file_list = []
    img_list = []

    # warmup 2 times
    if args.warmup:
        img = np.random.uniform(0, 255, [48, 320, 3]).astype(np.uint8)
        for i in range(2):
            res = text_recognizer([img] * int(args.rec_batch_num))

    for image_file in image_file_list:
        img = cv2.imread(image_file)
        valid_image_file_list.append(image_file)
        img_list.append(img)

    for i in range(10):
        t0 = time.time()
        rec_res, _ = text_recognizer(img_list)
        print((time.time() - t0) * 1000)

    for ino in range(len(img_list)):
        print("Predicts of {}:{}".format(valid_image_file_list[ino], rec_res[ino]))


if __name__ == "__main__":
    main(utility.parse_args())