demo中包括了目前常用的边缘检测算子，并添加了frei-chen、kirsch、drecedge、prewittcompass等边缘检测function函数。此外，实现了Ruzon罗盘算则的matlab编程，可以对灰度图像加以处理，实现边缘检测。-demo includes the most commonly used edge detection operator, and added frei-chen, kirsch, drecedge functions such as edge de