本文主要讲讲怎样改变图片的对比度和亮度，其实就是图片像素值线性变化了而已，对比度对应线性变化的系数，亮度对应其常量。参考资料为opencv自带tutiol及其code.

　　开发环境：ubuntu12.04+opencv2.4.2+Qt4.8.2+QtCreator2.5.

　　实验功能：

　　单击Open image按钮，在电脑中打开一张图片并显示出来。

　　拖动Contrast滑动条，改变对比度的值，可以看到对比度值的改变过程在滑动条下方显示，左边图片对应为其对比度改变后的效果。

　　拖动Brightness滑动条，改变亮度值，以看到亮度值的改变过程在滑动条下方显示，左边图片对应为其亮度改变后的效果。

　　点击Close按钮，退出程序。-In this paper, talk about how to change the contrast and brightness of the picture, in fact, the image pixel values ​ ​ linear change only, the contrast corresponds to the coefficient of linear change, the brightness corresponding constant. Reference to own tutiol its code opencv development environment: the ubuntu12.04+opencv2.4.2+Qt4.8.2+QtCreator2.5 experimental feature: click Open image button in the computer to open a picture and display it. Drag the Contrast slider to change the value of the contrast, you can see the contrast value of the process of change in the slider below the left picture corresponds to the effect of its contrast change. Drag the Brightness slider to change the brightness value, the slider below to see the changes in the brightness values ​ ​ in the left picture corresponds to its effect in the brightness changes. Click the Close button to exit the program.