cropping a bounding box and segmentation box from image

crop_bb_and_mask.py

def crop_all_components(self,
                        page_img_path: str,
                        save_root_folder: str,
                        original_img_shape: Tuple[int, int, int],  # h, w, c
                        transformed_img_shape: Tuple[int, int, int]):
    comic_series, page = page_img_path.split('/')[-2:]
    page = page.split('.')[0]

    scale_h_w = np.array(original_img_shape[:2]) / np.array(transformed_img_shape[:2])

    img = cv2.imread(page_img_path)

    def crop_with_mask(mask):
        mask_resized = cv2.resize(mask, (original_img_shape[:2][1], original_img_shape[:2][0]))
        contours, _ = cv2.findContours(mask_resized, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)
        largest_contour = max(contours, key=cv2.contourArea)
        blank_mask = np.zeros_like(img)
        cv2.drawContours(blank_mask, contours, -1, (255, 255, 255), thickness=cv2.FILLED)
        masked_image = cv2.bitwise_and(img, blank_mask)
        x, y, w, h = cv2.boundingRect(largest_contour)
        cropped_image = masked_image[y:y + h, x:x + w]
        return cropped_image

    def crop(bb,
             scale: Optional[float] = None,
             make_square: bool = False):
        x_min, y_min, x_max, y_max = bb

        if scale is not None or make_square:
            center_x = (x_min + x_max) // 2
            center_y = (y_min + y_max) // 2
            width = x_max - x_min
            height = y_max - y_min

            if make_square:
                width, height = max(width, height), max(width, height)

            if scale is not None:
                width, height = width * scale, height * scale

            x_min, x_max = center_x - width // 2, center_x + width // 2
            y_min, y_max = center_y - height // 2, center_y + height // 2

        x_min, x_max = int(x_min * scale_h_w[1]), int(x_max * scale_h_w[1])
        y_min, y_max = int(y_min * scale_h_w[0]), int(y_max * scale_h_w[0])
        return img[y_min:y_max, x_min:x_max]

    # save comic book panel
    panel_path = os.path.join(save_root_folder,
                              'panel',
                              str(comic_series),
                              str(page),
                              f'{self.box_id}.jpg')
    os.makedirs(os.path.dirname(panel_path), exist_ok=True)
    cv2.imwrite(panel_path, crop(self.box))