这是一段实现对比度拉伸的VC的程序代码，只是简单的实现，有待加强-This is a realization of the contrast stretching of the VC program code, but simply the realization needs to be strengthened

簡單的繪圖軟件,可以用拉伸的方法畫直線，圆，矩形，-Simple drawing software, you can use a method of stretching painting straight lines, circles, rectangles,