Question

我想只查看RGB图像中的R + G通道，因为当蓝色通道被移除时，我会更好地对比检测对象。我使用OpenCV来分割通道，但是在将蓝色通道设置为0之后合并它时，我的代码无法编译。

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>

using namespace cv;
using namespace std;

int main( int argc, char** argv )
{
    if( argc != 2)
    {
     cout <<" Usage: display_image ImageToLoadAndDisplay" << endl;
     return -1;
    }

    Mat image,fin_img;
    image = imread(argv[1], CV_LOAD_IMAGE_COLOR);   // Read the file

    if(! image.data )                              // Check for invalid input
    {
        cout <<  "Could not open or find the image" << std::endl ;
        return -1;
    }

   namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display.
                      // Show our image inside it.

    // Create Windows
    namedWindow("Red",1);
    namedWindow("Green",1);
    namedWindow("Blue",1);

    // Create Matrices (make sure there is an image in input!)

    Mat channel[3];
    imshow( "Original Image", image ); 


    // The actual splitting.
    split(image, channel);


   channel[0]=Mat::zeros(Size(image.rows, image.cols), CV_8UC1);//Set blue channel to 0

    //Merging red and green channels

    merge(channel,image);
    imshow("R+G", image);

    waitKey(0);//Wait for a keystroke in the window
    return 0;
}

我可以对我出错的地方有任何反馈意见吗？我怀疑它是将蓝色通道设置为0.有没有更好的方法将其设置为0？有没有办法使用cvMixChannels（）来做到这一点？

Answer 1

您需要更改这些行

    channel[0]=Mat::zeros(Size(image.rows, image.cols), CV_8UC1);//Set blue channel to 0

    //Merging red and green channels
    merge(channel,image);

到

    channel[0]=Mat::zeros(image.rows, image.cols, CV_8UC1);//Set blue channel to 0

    //Merging red and green channels
    merge(channel,3,image);

修改

根据您的评论，这里是完整的代码和结果。

#include <iostream> #include "opencv2/opencv.hpp" #include <stdio.h> using namespace cv; using namespace std; int main( int argc, char** argv ) { if( argc != 2) { cout <<" Usage: display_image ImageToLoadAndDisplay" << endl; return -1; } Mat image,fin_img; image = imread("bgr.png", CV_LOAD_IMAGE_COLOR); // Read the file if(! image.data ) // Check for invalid input { cout << "Could not open or find the image" << std::endl ; return -1; } namedWindow( "Display window", CV_WINDOW_AUTOSIZE );// Create a window for display. // Show our image inside it. // Create Windows namedWindow("Red",1); namedWindow("Green",1); namedWindow("Blue",1); // Create Matrices (make sure there is an image in input!) Mat channel[3]; imshow( "Original Image", image ); // The actual splitting. split(image, channel); channel[0]=Mat::zeros(image.rows, image.cols, CV_8UC1);//Set blue channel to 0 //Merging red and green channels merge(channel,3,image); imshow("R+G", image); imwrite("dest.jpg",image); waitKey(0);//Wait for a keystroke in the window return 0; }

来源图片

没有蓝色组件的结果

Answer 2

好吧，我开始使用mixChannels（）：我在上面的代码片段中添加了一个附加内容：

Mat gr( image.rows, image.cols, CV_8UC3);

// forming an array of matrices is a quite efficient operation,
// because the matrix data is not copied, only the headers
   Mat out[] = {gr};
// bgr[1] -> gr[1],
// bgr[2] -> gr[2], 
int from_to[] = {1,1, 2,2 };
mixChannels( &image, 1, out, 2, from_to, 2 );

imshow("R+G",gr);

由于戒日

Answer 3

执行此操作的最有效方法是不进行任何拆分和合并。这节省了时间和内存。

使用cv::Scalar(0,255,255)按位与您的图像进行对比，这会将您的蓝色通道设置为零。

如：imshow("R+G", src & cv::Scalar(0,255,255));。

Answer 4

另一种方法是从源图像中减去Scalar(255,0,0)

#include <opencv2/opencv.hpp>
using namespace cv;

int main(int argc, char **argv)
{
    Mat src = imread(argv[1], CV_LOAD_IMAGE_COLOR);
    imshow("src", src );
    src -= Scalar(255,0,0);
    imshow("Green and Red channels", src );
    waitKey();
    return 0;
}

OpenCV：拍摄3通道RGB图像，分割通道并仅使用R + G查看图像

4 个答案: