opencv copy data from a *Mat to a Mat

Question

I have two cv::Mat objects:

cv::Mat *frameLeftRemap;
cv::Mat frameLeft2;

Data streams into *frameLeftRemap from a camera. I need to copy the data to frameLeft2, then delete frameLeftRemap, to avoid the frame artifacts I am seeing. (This was suggested by the camera manufacturer support desk.)

the function is:

  void ProcessImageLeft(AVT::VmbAPI::FramePtr pFrame)
    {
        VmbUchar_t *pBuffer;
        VmbUint32_t FrameWidth;
        VmbUint32_t FrameHeight;


        //prepare frame information:
        pFrame->GetWidth(FrameWidth);
        pFrame->GetHeight(FrameHeight);
        pFrame->GetImage(pBuffer);
        //edited
        Mat1b imageL(FrameHeight, FrameWidth, (uchar*)pBuffer);

        cv::remap(imageL, *frameLeftRemap, mx1, my1, cv::INTER_LINEAR);

        frameLeft2 = frameLeftRemap->clone(); 

        //frameLeftRemap->copyTo(frameLeft2);


        cv::imshow("right", frameLeft2);
        cv::waitKey(1);
        delete frameLeftRemap;


    }

both copyTo and clone give an error:

this is nullPtr. read access violation

What am I doing wrong here?

Answer 1

frameL= frameLeftRemap->clone(); should work correctly. It seems you have problem in frameL . Try to show it using cv::imshow or cv::imwrite to make sure it was corrupted before cloning it. Then fix the original problem. If you posted code, we would help you more.