Method normalize_image

ddddocr/preprocessing/image_processor.py:82–122

标准化图像像素值 Args: image: 输入图像 target_mean: 目标均值 target_std: 目标标准差 Returns: 标准化后的numpy数组 Raises: ImageProcessError: 当处理失败时

(image: Union[Image.Image, np.ndarray], 
                       target_mean: float = 0.0, target_std: float = 1.0)

    
    @staticmethod
    def normalize_image(image: Union[Image.Image, np.ndarray], 
                       target_mean: float = 0.0, target_std: float = 1.0) -> np.ndarray:
        """
        标准化图像像素值
        
        Args:
            image: 输入图像
            target_mean: 目标均值
            target_std: 目标标准差
            
        Returns:
            标准化后的numpy数组
            
        Raises:
            ImageProcessError: 当处理失败时
        """
        try:
            if isinstance(image, Image.Image):
                img_array = image_to_numpy(image)
            else:
                img_array = image.copy()
            
            # 转换为float32并归一化到[0,1]
            img_array = img_array.astype(np.float32) / 255.0
            
            # 计算当前均值和标准差
            current_mean = np.mean(img_array)
            current_std = np.std(img_array)
            
            # 避免除零
            if current_std == 0:
                current_std = 1.0
            
            # 标准化
            normalized = (img_array - current_mean) / current_std
            normalized = normalized * target_std + target_mean
            
            return normalized
            
        except Exception as e:
            raise ImageProcessError(f"图像标准化失败: {str(e)}") from e
    
    @staticmethod
    def enhance_contrast(image: Image.Image, factor: float = 1.5) -> Image.Image: