c++winforms visual-studio opencv video-capture

OpenCV Webcam feed not displaying in PictureBox visual studio 2015

Hi so I used opencv to get webcam feed from my default camera and I wish to display it in a picturebox on my windows form. My webcam comes on but for some reason, the feed is never displayed on my picturebox. Please could someone help point out/solve the issue as I am stuck here right now. Thanks in advance.

In myform.h, I have this code to send the picturebox to the myform.cpp file:

System::Windows::Forms::PictureBox^ mypicbox1(void)  
{
    opencv_gui::MyForm aform;
    return aform.pictureBox1;
}

and the code to draw get the videofeed and put into my picture box in myform.cpp is:

void opencv_gui::DrawCvImage(const cv::Mat& cvImage)
{
    System::Windows::Forms::PictureBox^ pictureBox = mypicbox1();
    // only color images are supported
    assert(cvImage.type() == CV_8UC3);

    if ((pictureBox->Image == nullptr) || (pictureBox->Width != cvImage.cols) || (pictureBox->Height != cvImage.rows))
    {
        pictureBox->Width = cvImage.cols;
        pictureBox->Height = cvImage.rows;
        pictureBox->Image = gcnew System::Drawing::Bitmap(cvImage.cols, cvImage.rows);
    }

    // Create System::Drawing::Bitmap from cv::Mat
    System::Drawing::Bitmap^ bmpImage = gcnew System::Drawing::Bitmap(
        cvImage.cols, cvImage.rows, cvImage.step,
        System::Drawing::Imaging::PixelFormat::Format24bppRgb,
        System::IntPtr(cvImage.data)
    );

    // Draw Bitmap over a PictureBox
    System::Drawing::Graphics^ g = System::Drawing::Graphics::FromImage(pictureBox->Image);

    g->DrawImage(bmpImage, 0, 0, cvImage.cols, cvImage.rows);
    pictureBox->Refresh();

    delete g;
}


//camera feed
int opencv_gui::video_cap(void)
{
    VideoCapture cap;

    if (!cap.open(0)) // open the default camera (camera 0), use something different from 0 otherwise;
        return 0;
    for (;;)
    {
        Mat frame;
        cap >> frame;
        if (frame.empty()) break; // end of video stream
        DrawCvImage(frame);
        if (waitKey(10) == 27) break; // stop capturing by pressing ESC 
    }
    // the camera will be closed automatically upon exit
    // cap.close();
    return 0;
}

This is my debug log: I have used arrows like ">>>>>>>" to show important parameters and the words "RED >>>>>>>" to show error parameters.

cvImage { flags=1124024336 dims=2 rows=480 ...} cv::Mat&
allocator 0x0000000000000000 cv::MatAllocator*

cols 640 int
data 0x0000026AC2146F80 unsigned char* *(*cvImage).data 0 '' unsigned char
dataend 0x0000026AC2227F80 unsigned char*
datalimit 0x0000026AC2227F80 unsigned char*
datastart 0x0000026AC2146F80 unsigned char* dims 2 int flags 1124024336 int rows 480 int
size { p=0x000000DBDFF0DE80 } cv::MatSize
p 0x000000DBDFF0DE80 int* *(*cvImage).size.p 0 int
step { p=0x000000DBDFF0DEC8 buf={Length=2} } cv::MatStep
buf {Length=2} unsigned __int64[]
p 0x000000DBDFF0DEC8 unsigned __int64*
u 0x0000026AA4814780 cv::UMatData*
RED >>>>>>> bmpImage 0x0000026aa62a1fd0 { defaultTransparentColor= } System::Drawing::Bitmap^
RED >>>>>>> System::Drawing::Image^ 0x0000026aa62a1fd0 { nativeImage=2657511292512 rawData= userData= } System::Drawing::Image^ defaultTransparentColor System::Drawing::Color g System::Drawing::Graphics^
RED >>>>>>> pictureBox 0x0000026aa62a1388 { borderStyle=System::Windows::Forms::BorderStyle::None image=0x0000026aa62a1fa0 sizeMode=System::Windows::Forms::PictureBoxSizeMode::Normal ...} System::Windows::Forms::PictureBox^
RED >>>>>>> System::Windows::Forms::Control^ 0x0000026aa62a1388 { ControlKeyboardRouting= PaletteTracing= FocusTracing= ...} System::Windows::Forms::Control^ AllowDrop false bool BorderStyle System::Windows::Forms::BorderStyle::None System::Windows::Forms::BorderStyle CausesValidation true bool
CreateParams 0x0000026aa62a15d8 { className= caption= style=1442840576 ...} System::Windows::Forms::CreateParams^ DefaultImeMode System::Windows::Forms::ImeMode::Disable System::Windows::Forms::ImeMode
DefaultSize {Width=100 Height=50} System::Drawing::Size EVENT_SIZEMODECHANGED 0x0000026aa629af50 System::Object^
ErrorImage 0x0000026aa629b110 { nativeImage=2657511192608 rawData= userData= } System::Drawing::Image^
Font 0x0000026aa6280148 {} System::Drawing::Font^
ForeColor {RGB=0x0} System::Drawing::Color
Image 0x0000026aa62a1fa0 { nativeImage=2657511290992 rawData= userData= } System::Drawing::Image^
[System::Drawing::Bitmap^] 0x0000026aa62a1fa0 { defaultTransparentColor= } System::Drawing::Bitmap^
System::MarshalByRefObject^ 0x0000026aa62a1fa0 { __identity= } System::MarshalByRefObject^ Flags 2 int
FrameDimensionsList {Length=1} array ^ Height 480 int HorizontalResolution 96.000000 float
Palette 0x0000026aa62a25e8 { flags=1129621568 entries={Length=0} } System::Drawing::Imaging::ColorPalette^
PhysicalDimension { width=640.00000 height=480.00000 } System::Drawing::SizeF PixelFormat System::Drawing::Imaging::PixelFormat::Format32bppArgb System::Drawing::Imaging::PixelFormat PropertyIdList {Length=0} array ^ PropertyItems {Length=0} array ^
RawFormat 0x0000026aa62a3488 { ...} System::Drawing::Imaging::ImageFormat^
Size {Width=640 Height=480} System::Drawing::Size Tag System::Object^ VerticalResolution 96.000000 float Width 640 int nativeImage 2657511290992 __int64 rawData array ^ userData System::Object^ ImageLocation System::String^
ImageRectangle {X=0 Y=0 Width=640 Height=480} System::Drawing::Rectangle ImeMode System::Windows::Forms::ImeMode::Disable System::Windows::Forms::ImeMode
InitialImage 0x0000026aa629c568 { nativeImage=2657511196256 rawData= userData= } System::Drawing::Image^ PICTUREBOXSTATE_asyncOperationInProgress 1 int PICTUREBOXSTATE_cancellationPending 2 int PICTUREBOXSTATE_inInitialization 64 int PICTUREBOXSTATE_needToLoadImageLocation 32 int PICTUREBOXSTATE_useDefaultErrorImage 8 int PICTUREBOXSTATE_useDefaultInitialImage 4 int PICTUREBOXSTATE_waitOnLoad 16 int RightToLeft System::Windows::Forms::RightToLeft::No System::Windows::Forms::RightToLeft SizeMode System::Windows::Forms::PictureBoxSizeMode::Normal System::Windows::Forms::PictureBoxSizeMode TabIndex 1 int TabStop false bool Text "" System::String^ WaitOnLoad false bool borderStyle System::Windows::Forms::BorderStyle::None System::Windows::Forms::BorderStyle contentLength 0 int currentAsyncLoadOperation System::ComponentModel::AsyncOperation^ currentlyAnimating false bool
defaultErrorImage 0x0000026aa629b110 { nativeImage=2657511192608 rawData= userData= } System::Drawing::Image^
defaultErrorImageForThread 0x0000026aa629b110 { nativeImage=2657511192608 rawData= userData= } System::Drawing::Image^ defaultErrorImageKey 0x0000026aa629af08 System::Object^
defaultInitialImage 0x0000026aa629c568 { nativeImage=2657511196256 rawData= userData= } System::Drawing::Image^
defaultInitialImageForThread 0x0000026aa629c568 { nativeImage=2657511196256 rawData= userData= } System::Drawing::Image^ defaultInitialImageKey 0x0000026aa629aef0 System::Object^
errorImage 0x0000026aa629b110 { nativeImage=2657511192608 rawData= userData= } System::Drawing::Image^ handleValid false bool
image 0x0000026aa62a1fa0 { nativeImage=2657511290992 rawData= userData= } System::Drawing::Image^ imageInstallationType ImageInstallationType::DirectlySpecified ImageInstallationType imageLocation System::String^
initialImage 0x0000026aa629c568 { nativeImage=2657511196256 rawData= userData= } System::Drawing::Image^
[System::Drawing::Bitmap^] 0x0000026aa629c568 { defaultTransparentColor= } System::Drawing::Bitmap^
System::MarshalByRefObject^ 0x0000026aa629c568 { __identity= } System::MarshalByRefObject^ Flags 73744 int
FrameDimensionsList {Length=1} array ^ Height 16 int HorizontalResolution 96.000000 float
RED >>>>>>>Palette 0x0000026aa629ea60 { flags=951278840 entries={Length=0} } System::Drawing::Imaging::ColorPalette^
PhysicalDimension { width=14.000000 height=16.000000 } System::Drawing::SizeF PixelFormat System::Drawing::Imaging::PixelFormat::Format24bppRgb System::Drawing::Imaging::PixelFormat PropertyIdList {Length=0} array ^ PropertyItems {Length=0} array ^
RED >>>>>>> RawFormat 0x0000026aa629f900 { ...} System::Drawing::Imaging::ImageFormat^
Size {Width=14 Height=16} System::Drawing::Size Tag System::Object^ VerticalResolution 96.000000 float Width 14 int nativeImage 2657511196256 __int64 rawData array ^ userData System::Object^ RED >>>>>>> internalSyncObject 0x0000026aa629d900 System::Object^ loadCompletedDelegate System::Threading::SendOrPostCallback^ loadCompletedKey 0x0000026aa629af20 System::Object^ loadProgressChangedKey 0x0000026aa629af38 System::Object^ loadProgressDelegate System::Threading::SendOrPostCallback^ localImageStreamReader System::IO::StreamReader^
pictureBoxState { data=12 } System::Collections::Specialized::BitVector32 readBlockSize 4096 int readBuffer array ^
savedSize {Width=640 Height=480} System::Drawing::Size sizeMode System::Windows::Forms::PictureBoxSizeMode::Normal System::Windows::Forms::PictureBoxSizeMode tempDownloadStream System::IO::MemoryStream^ totalBytesRead 0 int uriImageStream System::IO::Stream^

Solution

Had to edit my code a bit but I pretty much solved my issue using the answer provided here: https://stackoverflow.com/a/12628861/5728859