说明：  1.图像反转 2.灰度线性变换 3.非线性变换 4.直方图均衡化 5.线性平滑滤波器 6.中值滤波器 8.梯度算子检测边缘 9.LOG算子检测边缘 10.Canny算子检测边缘 11.边界跟踪（bwtraceboundary函数） 等等
(Image reversal. Grayscale linear transform 3. Nonlinear transformation 4. Histogram equalization 5 linear smoothing filter median filter gradient operator the detected edge 9.LOG operator detection the edge 10.Canny operator edge detection 11. the boundary tracking the (bwtraceboundary function), etc.)