Converting a System.Windows.Media.Drawing object to Bitmap bytes

Question

I have a System.Windows.Media.Drawing object that I am wanting to convert into a Bitmap object, and then from there extract the bytes that represent the image. I've looked about the internet and I can't seem to find how to do what I need, so any help would be appreciated.

Answer 1

So I finally found a way to convert a System.Windows.Media.Drawing object to a System.Drawing.Bitmap object, and from that get a byte[] object representing the image data. The following is not pretty but does actually work.

public static byte[] DrawingToBytes(Drawing drawing)
{
    DrawingVisual visual = new DrawingVisual();
    using (DrawingContext context = visual.RenderOpen())
    {
        // If using the BitmapEncoder uncomment the following line to get a white background.
        // context.DrawRectangle(Brushes.White, null, drawing.bounds);
        context.DrawDrawing(drawing);
    }

    int width = (int)(drawing.Bounds.Width)
    int height = (int)(drawing.Bounds.Height)
    Bitmap bmp = new Bitmap(width, height);
    Bitmap bmpOut;

    using (Graphics g = Graphics.FromImage(bmp))
    {
        g.Clear(System.Drawing.Color.White);
        RenderTargetBitmap rtBmp = new RenderTargetBitmap(width, height, 
                                           bmp.HorizontalResolution,
                                           bmp.VerticalResolution,
                                           PixelFormats.Pbgra32);
        rtBmp.Render(visual);

        // Alternative using BmpBitmapEncoder, use in place of what comes after if you wish.
        // MemoryStream stream = new MemoryStream();
        // BitmapEncoder encoder = new BmpBitmapEncoder();
        // encoder.Frames.Add(BitmapFrame.Create(rtBmp));
        // encoder.save(stream);

        int stride = width * ((rtBmp.Format.BitsPerPixel + 7) / 8);
        byte[] bits = new byte[height * stride];
        bitmapSource.CopyPixels(bits, stride, 0);

        unsafe
        {
            fixed (byte* pBits = bits)
            {
                IntPtr ptr = new IntPtr(pBits);
                bmpOut = new Bitmap(width, height, stride,
                                    System.Drawing.Imaging.PixelFormat.Format32bppPArgb, ptr);
             }
        }

        g.DrawImage(bmpOut, 0, 0, bmp.Width, bmp.Height);
    }

    byte[] bytes;
    using (MemoryStream ms = new MemoryStream())
    {
        bmp.Save(ms, ImageFormat.bmp);
        data = ms.ToArray();
    }

    return bytes;
}

So yeah, it's horrible but it actually works.

Answer 2

You can try that:

byte[] ImageToByte(Image image)
    {
        ImageConverter converter = new ImageConverter();
        return (byte[])converter.ConvertTo(img, typeof(byte[]));
    }

This work also for Bitmap.