中文说明：
一段MATLAB图像处理程序，包括彩色图像转灰度图像，加噪后的中值滤波，sobel边缘提取，以及腐蚀，膨胀，开运算，闭运算等形态学处理
English Description：
A matlab image processing program, including color image to gray image, median filtering after noise, Sobel edge extraction, and morphological processing such as corrosion, expansion, open operation, closed operation