Question

I’m new to C++ and trying to add OpenCV into Microsoft’s Kinect samples. I was able to do it for the ColorBasics-D2D sample by modifying this function

void CColorBasics::ProcessColor()
{
HRESULT hr;
NUI_IMAGE_FRAME imageFrame;

// Attempt to get the color frame
hr = m_pNuiSensor->NuiImageStreamGetNextFrame(m_pColorStreamHandle, 0, &imageFrame);
if (FAILED(hr))
{
    return;
}

INuiFrameTexture * pTexture = imageFrame.pFrameTexture;

NUI_LOCKED_RECT LockedRect;

// Lock the frame data so the Kinect knows not to modify it while we're reading it
pTexture->LockRect(0, &LockedRect, NULL, 0);


// Make sure we've received valid data
if (LockedRect.Pitch != 0)
{
    BYTE * pBuffer = (BYTE*) LockedRect.pBits;

    cvSetData(img,(BYTE*) pBuffer, img->widthStep);
    Mat &m = Mat(img);
    Mat &hsv = Mat();
    vector<Mat> mv = vector<Mat>(3,Mat(cvSize(640,480),CV_8UC1));
    cvtColor(m,hsv,CV_BGR2HSV);
    cvtColor(hsv,m,CV_HSV2BGR);//*/
    IplImage iplimg(m);
    cvNamedWindow("rgb",1);
    cvShowImage("rgb",&iplimg);
    // Draw the data with Direct2D
    m_pDrawColor->Draw(static_cast<BYTE *>(LockedRect.pBits), LockedRect.size);

    // If the user pressed the screenshot button, save a screenshot
    if (m_bSaveScreenshot)
    {
        WCHAR statusMessage[cStatusMessageMaxLen];

        // Retrieve the path to My Photos
        WCHAR screenshotPath[MAX_PATH];
        GetScreenshotFileName(screenshotPath, _countof(screenshotPath));

        // Write out the bitmap to disk
        hr = SaveBitmapToFile(static_cast<BYTE *>(LockedRect.pBits), cColorWidth, cColorHeight, 32, screenshotPath);

        if (SUCCEEDED(hr))
        {
            // Set the status bar to show where the screenshot was saved
            StringCchPrintf( statusMessage, cStatusMessageMaxLen, L"Screenshot saved to %s", screenshotPath);
        }
        else
        {
            StringCchPrintf( statusMessage, cStatusMessageMaxLen, L"Failed to write screenshot to %s", screenshotPath);
        }

        SetStatusMessage(statusMessage);

        // toggle off so we don't save a screenshot again next frame
        m_bSaveScreenshot = false;
    }
}

// We're done with the texture so unlock it
pTexture->UnlockRect(0);

// Release the frame
m_pNuiSensor->NuiImageStreamReleaseFrame(m_pColorStreamHandle, &imageFrame);
}

This works fine. However, when I wanted to add something like this to the SkeletalViewer example, it is just displaying an empty window.

/// <summary>
/// Handle new color data
/// </summary>
/// <returns>true if a frame was processed, false otherwise</returns>
bool CSkeletalViewerApp::Nui_GotColorAlert( )
{
NUI_IMAGE_FRAME imageFrame;
bool processedFrame = true;

HRESULT hr = m_pNuiSensor->NuiImageStreamGetNextFrame( m_pVideoStreamHandle, 0, &imageFrame );

if ( FAILED( hr ) )
{
    return false;
}

INuiFrameTexture * pTexture = imageFrame.pFrameTexture;
NUI_LOCKED_RECT LockedRect;
pTexture->LockRect( 0, &LockedRect, NULL, 0 );
if ( LockedRect.Pitch != 0 )
{
    BYTE * pBuffer = (BYTE*) LockedRect.pBits;

    cvSetData(img,(BYTE*) pBuffer, img->widthStep);
    Mat m(img);
    IplImage iplimg(m);
    cvNamedWindow("rgb",1);
    cvShowImage("rgb",&iplimg);
    m_pDrawColor->Draw( static_cast<BYTE *>(LockedRect.pBits), LockedRect.size );
}
else
{
    OutputDebugString( L"Buffer length of received texture is bogus\r\n" );
    processedFrame = false;
}

pTexture->UnlockRect( 0 );

m_pNuiSensor->NuiImageStreamReleaseFrame( m_pVideoStreamHandle, &imageFrame );

return processedFrame;
}

I’m not sure why the same code doesn’t work in this example. I’m using Visual Studio 2010 and OpenCV 2.4.2.

Thanks

Answer 1

Figured it out. Changed it to this

if ( LockedRect.Pitch != 0 )
{
    BYTE * pBuffer = static_cast<BYTE *>(LockedRect.pBits);

    cvSetData(img,(BYTE*) pBuffer, img->widthStep);
    Mat m(img);
    IplImage iplimg(m);
    cvNamedWindow("rgb",1);
    cvShowImage("rgb",&iplimg);
    waitKey(1);
    m_pDrawColor->Draw( static_cast<BYTE *>(LockedRect.pBits), LockedRect.size );
}