rgb2hsv-color-space-exchange

代码说明：

  为了避免直接对rgb图像处理时出现颜色失真，常把彩色图像由rgb空间转为hsv空间，完成相应处理后，再逆变换至rgb空间。(In order to avoid image processing directly on the rgb color distortion occurs, often the color image from the rgb space into hsv space to complete the appropriate treatment, and then inverse transform to the rgb space.)