Method preprocess_for_ocr

ddddocr/preprocessing/image_processor.py:241–287

OCR预处理流水线 Args: image: 输入图像 target_height: 目标高度 enhance_contrast: 是否增强对比度 remove_noise: 是否去噪 Returns: 预处理后的图像 Raises: ImageProcessError: 当处理失败时

(image: Image.Image, target_height: int = 64, 
                          enhance_contrast: bool = True, 
                          remove_noise: bool = True)

    
    @staticmethod
    def preprocess_for_ocr(image: Image.Image, target_height: int = 64, 
                          enhance_contrast: bool = True, 
                          remove_noise: bool = True) -> Image.Image:
        """
        OCR预处理流水线
        
        Args:
            image: 输入图像
            target_height: 目标高度
            enhance_contrast: 是否增强对比度
            remove_noise: 是否去噪
            
        Returns:
            预处理后的图像
            
        Raises:
            ImageProcessError: 当处理失败时
        """
        try:
            processed_image = image.copy()
            
            # 处理PNG透明背景
            if processed_image.mode == 'RGBA':
                processed_image = png_rgba_black_preprocess(processed_image)
            
            # 调整尺寸（保持宽高比）
            original_width, original_height = processed_image.size
            target_width = int(original_width * (target_height / original_height))
            processed_image = ImageProcessor.resize_image(
                processed_image, (target_width, target_height), keep_aspect_ratio=False
            )
            
            # 增强对比度
            if enhance_contrast:
                processed_image = ImageProcessor.enhance_contrast(processed_image, factor=1.2)
            
            # 去噪
            if remove_noise:
                processed_image = ImageProcessor.remove_noise(processed_image, kernel_size=3)
            
            # 转换为灰度图
            processed_image = ImageProcessor.convert_to_grayscale(processed_image)
            
            return processed_image
            
        except Exception as e:
            raise ImageProcessError(f"OCR预处理失败: {str(e)}") from e