图像边缘是图像的重要特征，是图像中特性（如像素灰度、纹理等）分布的不连续处，图像周围特性有阶跃变化或屋脊状变化的那些像素集合。该段代码就是对边缘检测的描述。 -The image edge is an important feature of the image, and is the image characteristics (such as pixel gray, texture) distribution of discontinuous place, image character