sobel算子求出图像梯度,本程序中采用的是红色通道，可应用在抠图，目标提取-get the gradient of the image wiht sobel

自己写的基于传统的Sobel算子的二维图像滤波器，返回滤波后的梯度图像及边缘检测图像。-Write your own based on the traditional Sobel operator dimensional image filter, images and gradient edge detection image return filtered.