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） -Image reversal. Grayscale linear transform 3. Nonlinear transformation 4. Histogram equalization 5 linear smoothi

阈值分割、边缘检测、线性变换、均衡直方图等图像预处理的一些代码-Some code for image preprocessing, such as threshold segmentation, edge detection, linear transformation and equalization histogram