C# – Convert WPF Image.source to a System.Drawing.Bitmap

Actually you don’t need to use unsafe code. There’s an overload of CopyPixels that accepts an IntPtr:

public static System.Drawing.Bitmap BitmapSourceToBitmap2(BitmapSource srs)
{
    int width = srs.PixelWidth;
    int height = srs.PixelHeight;
    int stride = width * ((srs.Format.BitsPerPixel + 7) / 8);
    IntPtr ptr = IntPtr.Zero;
    try
    {
        ptr = Marshal.AllocHGlobal(height * stride);
        srs.CopyPixels(new Int32Rect(0, 0, width, height), ptr, height * stride, stride);
        using (var btm = new System.Drawing.Bitmap(width, height, stride, System.Drawing.Imaging.PixelFormat.Format1bppIndexed, ptr))
        {
            // Clone the bitmap so that we can dispose it and
            // release the unmanaged memory at ptr
            return new System.Drawing.Bitmap(btm);
        }
    }
    finally
    {
        if (ptr != IntPtr.Zero)
            Marshal.FreeHGlobal(ptr);
    }
}

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