The above file will give internal boundary, external boundary, morphological gradient, also thining and thickening of image.

利用idl语言实现图像的数学形态学开闭重建运算，比提取梯度图像。-Idl language use mathematical morphological opening and closing image reconstruction operations, compared to extract gradient image.

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 7.用Sobel算子和拉普拉斯对图像锐化：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）12.Hough变换 13.直方图阈值法 14. 自动阈值法：Otsu法 15.膨胀操作 16.腐蚀操作 17.开启和闭合操作 18.开启和闭合组合操作 19.形态学边界提取 20.形态学骨架提取 21.直接提取四个顶点坐标

Morphological transformations are some simple operations based on the image shape. It is normally performed on binary images. It needs two inputs, one is our original image, second one is called structuring element or kernel which decides the nature