1．利用工具（如ACDSee、PhotoShop）将*.jpg转换为*.bmp；

2．借助imread命令将图像内容读入内存数组；

3．通过访问数字图像RGB三个通道的对应矩阵，改变数字图像的色彩；

4．将数字图像的RGB表示转换为YUV表示；

Y=0.30R+0.59G+0.11B

U=0.70R-0.59G-0.11B

V=-0.30R-0.59G+0.89B

5．通过访问Y（亮度）通道，改变数字图像的亮度；

6．通过Y（亮度）通道作灰度的线性变换，改变数字图像的对比度。

-1. The use of tools (such as ACDSee, PhotoShop) to*. Jpg convert*. Bmp　2. With imread command reads the contents of the image memory array　3. By accessing the digital image matrix corresponding RGB three channels, changing the color of digital images　4. RGB representation of the digital image is converted to YUV means　Y = 0.30R+0.59G+0.11B U = 0.70R-0.59G-0.11BV =-0.30R-0.59G+0.89B 5. By accessing the Y (luminance) channel, change the brightness of digital images　6. By Y (luminance) channel for the gray linear transformation, to change the contrast of the digital image.