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

Chapter 3 of text book “Digital Image Processing” Gonzales named Intensity Transformations and Spatial Filtering, which consists of 6 sub-sections including (1) Basics intensity transformation functions, (2) Histogram Processing, (3) Spatial Filterin