请问这里的Mat类型变量跟1进行&位运算是什么意思？

Question

偶尔在OpenCV图像处理中遇到Mat类型变量跟0、1进行位运算，但没找到过相关内容的指导。

#include <iostream>
#include <opencv2/opencv.hpp>
using namespace std;
using namespace cv;
 
int main()
{
 
    Mat srcImage = imread("D://vvoo//group.jpg");
 
    Mat mask;
    Mat foreground;
 
    Rect rect(0, 100, 500, 200);
    Mat bkgModel, fgrModel; // the models (internally used)
 
    // GrabCut segmentation
    grabCut(srcImage,  // input image
        mask, // segmentation result
        rect, bkgModel, fgrModel, 5, GC_INIT_WITH_RECT);
 
    // Get the pixels marked as likely foreground、

    //就是这句话------------------------------------------------------------------------------------------------------------------------------------------------
    mask = mask & 1;//try to find forgeground
    //就是上面那句话------------------------------------------------------------------------------------------------------------------------------------------

    foreground.create(srcImage.size(), CV_8UC3);
    foreground.setTo(Scalar(255, 255, 255));
    srcImage.copyTo(foreground, mask); // pixels of background are not copied;pixels of srcImage is copied if mask isn't zero 
 
     // draw rectangle on original image
    rectangle(srcImage, rect, Scalar(255, 255, 255), 1);
    imshow("Original Image", srcImage);
 
    // display result
    imshow("Foreground objects", foreground);
 
    waitKey();
    return 0;
}

Answer 1

mask = mask & 1/0等同于bitwise_and
见： https://kdr2.com/tech/main/1810-elewise-matrix-op-opencv.html