下面的代码用于访问转换为矩阵的 3 个 RGB 图像的元素,并将它们放在一个更大的矩阵中。但是,我知道 CV_MAT_ELEM(mat, type, row, col) 仅用于访问单 channel 矩阵的元素,而我的图像都是 3 channel 的。那么我是否会着手修复此代码以访问 3 channel 矩阵而不是单 channel 矩阵的元素?
#include "cv.h"
#include "highgui.h"
#include "iostream"
using namespace std;
void cvDoubleMatPrint (const CvMat* mat)
{
int i, j;
for (i = 0; i < mat->rows; i++)
{
for (j = 0 ; j < mat->cols; j++)
{
printf ( "%f ", cvGet2D (mat, i , j));
}
printf ( "\n" );
}
}
int main( int argc, char* argv )
{
CvMat *img0, *img1, *img2, *img0_mat, *img1_mat, *img2_mat, *col0, *col1, *col2, *superMat = NULL;
img0 = cvLoadImageM("C:\\small\\walk mii.jpg", CV_LOAD_IMAGE_UNCHANGED);
img1 = cvLoadImageM("C:\\small\\wave mii.jpg", CV_LOAD_IMAGE_UNCHANGED);
img2 = cvLoadImageM("C:\\small\\fantasy.jpg", CV_LOAD_IMAGE_UNCHANGED);
CvMat img0_header ,img1_header, img2_header;
col0 = cvReshape(img0, &img0_header, 0, 4800);
col1 = cvReshape(img1, &img1_header, 0, 4800);
col2 = cvReshape(img2, &img2_header, 0, 4800);
superMat = cvCreateMat(4800, 3, CV_8UC1);
cvSetZero(superMat);
for(int i=0; i<col0->height; i++)
{
CV_MAT_ELEM( *superMat, double, i, 0 ) = CV_MAT_ELEM( *col0, double, i, 0 );
}
for(int j=0; j<col1->height; j++)
{
CV_MAT_ELEM( *superMat, double, j, 1 ) = CV_MAT_ELEM( *col1, double, j, 0 );
}
for(int k=0; k<col2->height; k++)
{
CV_MAT_ELEM( *superMat, double, k, 2 ) = CV_MAT_ELEM( *col2, double, k, 0 );
}
cvDoubleMatPrint(superMat);
cvWaitKey(0);
return 0;
最佳答案
我对 C API 不太熟悉,但这里介绍了如何使用 C++ API 完成您正在做的事情。
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
#include <vector>
using namespace cv;
using namespace std;
int main(int /*argc*/, char** /*argv*/)
{
cv::RNG rng = cv::theRNG();
// create 3 random 10x10 matrices to simulate your situation.
vector<Mat> matrices;
for(int i = 0; i < 3; i++)
{
Mat temp(Size(10, 10), CV_64FC3);
rng.fill(temp, RNG::UNIFORM, 0.0, 1.0);
matrices.push_back(temp);
}
// reshape the matrices to have 1 row and 1 channel (i.e., 10x10x3 -> 300x1).
vector<Mat> singleRows;
vector<Mat>::iterator i;
for(i = matrices.begin(); i != matrices.end(); i++)
{
singleRows.push_back(i->reshape(1, 1));
}
// finally, concatenate the matrices to make a 300x3 matrix.
Mat concatenated;
for(i = singleRows.begin(); i != singleRows.end(); i++)
{
concatenated.push_back(i->clone());
}
cout << concatenated.size().width << "x" << concatenated.size().height << endl;
return 0;
}
如果您需要在 C++ API 中访问 RGB 值,请参阅我的 other post关于如何使用 cv::Vec3b
类。一般来说,我建议使用 C++ API 而不是 C API,因为它具有更多功能并且更易于使用。另外,看看 OpenCV 函数 split和 merge .这些功能对于多 channel 管理很有用。希望对您有所帮助!
关于c++ - 访问 3 channel 矩阵的元素,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/9704587/