可以把图片裁剪成规定尺寸或比例的大小。在index.php页面可以选择裁剪的模式，把要裁剪的图片放在change_before文件夹中，裁剪之后的图片会自动保存到changed文件夹中。(The picture can be cut to the size of the specified size or proportion. On the index.php page, you can choose the pattern of clipping, put the pictures you want to cut in the change_before folder, and save the pictures after clipping to the changed folder automatically.)