掩膜

掩膜计算

步骤

  1.获取原图像的高度和宽度以及通道数。
  2.生成一个和原图同样大小的初始图。
  3.遍历每个像素点。获取每个像素点的当前行指针，前一行指针和后一行指针
  4.进行掩膜计算。

计算图解

代码

Mat inputImage=imread("d:/image/test01.jpg");
namedWindow("inputWindow",WINDOW_NORMAL);
resizeWindow("inputWindow",300,400);
imshow("inputWindow",inputImage);
Mat out=Mat::zeros(inputImage.size(),inputImage.type());
int rows=inputImage.rows;
int offset=inputImage.channels();
int cols=(inputImage.cols-1)*offset;
for (int row=1;row<rows-1;row++){
    const uchar* previous=inputImage.ptr<uchar>(row-1);
    const uchar* current=inputImage.ptr<uchar>(row);
    const uchar* next=inputImage.ptr<uchar>(row+1);
    uchar * output=out.ptr<uchar>(row);
    for(int col=offset;col<cols-offset;col++){
        output[col]=saturate_cast<uchar>(5*current[col]-current[col-offset]-current[col+offset]-previous[col]-next[col]);;
    }
}
namedWindow("outputWindow",WINDOW_NORMAL);
resizeWindow("outputWindow",300,400);
imshow("outputWindow",out);

opencv自带函数Filter2D

  void filter2D(InputArray src, OutputArray dst, int ddepth, InputArray kernel,Point anchor=Point(-1,-1),double delta=0, 
                int,borderType=BORDER_DEFAULT );