读入一幅图像，分别对其进行增加对比度，减少对比度，线性增加亮度和线性减少亮度的处理。接着又分别对4幅图像进行了直方图均衡化处理。灰度归一化用于消除灰度因素造成的图像外观变换。-Read into an image, with respect to their increase contrast, reduce contrast, the linear increase in processing of brightness and linear decrease in brightness. F