extremum

代码说明：

  对读入的两幅图像进行逐个像元比较，取其中最大或最小值形成新图像矩阵，输出。 已形成界面。可通过界面进行上述操作。(To read the two images pixel-by-comparison, the maximum or minimum value from which to form a new image matrix, the output. Interface has formed. Through the interface to carry out such operations.)