把目标范围缩小到一个小矩形内，将图像的G通道单独抽出作分析，抽出来的是一个灰度图，现在需要将目标从背景中提取出来。使用imadjust函数增强图像对比度时可以使用stretchlim传递给imadjust灰度范围，matlab循环调用图片进行处理-The target was restricted to a small rectangle, the image of the G-channel single out for analysis, out of is a grayscale, and

通过matlab软件，编写程序用stretchlim和imadjust进行图像增强(Through MATLAB software, the program is written with stretchlim and imadjust for image enhancement)