Convert C# Bitmap to Opencv Mat

Conversion from C# bitmap to Opencv Mat isn't a difficult task. But this conversion needs to be done from the primitive level of both Opencv Mat and C# Bitmap. Simply all the images are created from set of bytes, therefore it is necessary to create cv::Mat from bytes of System.Drawing.Bitmat. Also you will need to do this conversion in a CLI project. Total instructions can be found in following 2 articles.

1. Call Opencv functions from C#
2. Call Opencv functions from C# with bitmap

This article describes how to convert Opencv Mat to C# Bitmap.
Convert Opencv Mat to C# Bitmap

If you already know how to create and configure CLI project in visual studio, simply use following function in CLI project to convert C# Bitmap to Opencv Mat.

Mat BitmapToMat(System::Drawing::Bitmap^ bitmap)
{
    IplImage* tmp;

    System::Drawing::Imaging::BitmapData^ bmData = bitmap->LockBits(System::Drawing::Rectangle(0, 0, bitmap->Width, bitmap->Height), System::Drawing::Imaging::ImageLockMode::ReadWrite, bitmap->PixelFormat);
    if (bitmap->PixelFormat == System::Drawing::Imaging::PixelFormat::Format8bppIndexed)
    {
        tmp = cvCreateImage(cvSize(bitmap->Width, bitmap->Height), IPL_DEPTH_8U, 1);
        tmp->imageData = (char*)bmData->Scan0.ToPointer();
    }

    else if (bitmap->PixelFormat == System::Drawing::Imaging::PixelFormat::Format24bppRgb)
    {
        tmp = cvCreateImage(cvSize(bitmap->Width, bitmap->Height), IPL_DEPTH_8U, 3);
        tmp->imageData = (char*)bmData->Scan0.ToPointer();
    }

    bitmap->UnlockBits(bmData);

    return Mat(tmp);
}