How to create a Image or Mat instance from a YUV_420_888 byte array in EmguCV?

user_7745011 0
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The problem: I receive a YUV_420_888 image from an android device as a byte buffer (simply concatenated the image plane buffers). I know the dimension of the image and I need to display it onto my GUI.

What I have so far: At the moment I can use only the grayscale Y-plane with the following function:

private BitmapImage GetImageFromBuffer(byte[] imgBuffer)
{
    Image<Gray, byte> emguImg = new Image<Gray, byte>(1280, 720);
    emguImg.Bytes = imgBuffer;

    var img = new BitmapImage();
    using (MemoryStream ms = new MemoryStream(emguImg.ToJpegData()))
    {
        img.BeginInit();
        img.CacheOption = BitmapCacheOption.OnLoad;
        img.CreateOptions = BitmapCreateOptions.PreservePixelFormat;
        img.StreamSource = ms;
        img.EndInit();
    }
    return img;
}

I also have tested a similar code, using Image.ToBitmap() function and copying the intermediate Bitmap to the memory stream, which serves as source for the BitmapImage. Anyway, I would like to create a BitmapImage of BitmapSource (or any type I can use to display on the GUI) from the incoming byte[]. As far as I could read up on it, I have to create a Mat instance from the byte array, convert it to RGB and then save it to a diplay-able format.

emgucv wpf c#
1 Answers

The following code seems to do the trick:

private BitmapImage GetImageFromBuffer(byte[] imgBuffer)
{
    unsafe
    {
        fixed (byte* p = imgBuffer)
        {
            IntPtr ptr = (IntPtr)p;
            Mat yuvMat = new Mat(1080, 1280, Emgu.CV.CvEnum.DepthType.Cv8U, 1, ptr, 1280);
            Mat rgbMat = new Mat();
            CvInvoke.CvtColor(yuvMat, rgbMat, Emgu.CV.CvEnum.ColorConversion.Yuv420Sp2Rgb);
            var img = new BitmapImage();
            using (MemoryStream ms = new MemoryStream())
            {
                img.BeginInit();
                rgbMat.Bitmap.Save(ms, ImageFormat.Bmp);
                img.CacheOption = BitmapCacheOption.OnLoad;
                img.CreateOptions = BitmapCreateOptions.PreservePixelFormat;
                img.StreamSource = ms;
                img.EndInit();
            }
            return img;
        }
    }
}

Maybe someone can confirm, if this is the way to go or comment suggestions for improvements.

user_77450110
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