Question

As far as I can tell the only way to convert from BitmapSource to Bitmap is through unsafe code… Like this (from Lesters WPF blog):

myBitmapSource.CopyPixels(bits, stride, 0);

unsafe
{
  fixed (byte* pBits = bits)
  {
      IntPtr ptr = new IntPtr(pBits);

      System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(
        width,
        height,
        stride,
        System.Drawing.Imaging.PixelFormat.Format32bppPArgb,ptr);

      return bitmap;
  }
}

To do the reverse:

System.Windows.Media.Imaging.BitmapSource bitmapSource =
  System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
    bitmap.GetHbitmap(),
    IntPtr.Zero,
    Int32Rect.Empty,
    System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());

Is there an easier way in the framework? And what is the reason it isn’t in there (if it’s not)? I would think it’s fairly usable.

The reason I need it is because I use AForge to do certain image operations in an WPF app. WPF wants to show BitmapSource/ImageSource but AForge works on Bitmaps.

Answer 1

It is possible to do without using unsafe code by using Bitmap.LockBits and copy the pixels from the BitmapSource straight to the Bitmap

Bitmap GetBitmap(BitmapSource source) {
  Bitmap bmp = new Bitmap(
    source.PixelWidth,
    source.PixelHeight,
    PixelFormat.Format32bppPArgb);
  BitmapData data = bmp.LockBits(
    new Rectangle(Point.Empty, bmp.Size),
    ImageLockMode.WriteOnly,
    PixelFormat.Format32bppPArgb);
  source.CopyPixels(
    Int32Rect.Empty,
    data.Scan0,
    data.Height * data.Stride,
    data.Stride);
  bmp.UnlockBits(data);
  return bmp;
}