灰度变换是将一个灰度区间映射到另一个灰度区间的变换。灰度变换可使图像动态范围加大，图像对比度扩展，图像清晰，特征明显，是图像增强的重要手段。-Gray-scale transformation to a grayscale range is mapped to another gray range transformations. Gray-scale transformation can increase the dynamic range image, the image contrast