Sobel算子就是一种基于方向导数掩模求卷积的方法。通过边缘检测算子可以检测到每个像素的领域并对灰度变化率进行量化，也包括方向的确定。该代码是基于sobel算法的检测程序。-Sobel operator is a directional derivative mask and convolution methods. To each pixel and gray level in the field rate of change can be detected through the edge