WPF/WinForms/GDI interop: converting a WriteableBitmap to a System.Drawing.Image?

Question

How can I convert a WPF WriteableBitmap object to a System.Drawing.Image?

My WPF client app sends bitmap data to a web service, and the web service needs to construct a

Answer 1

If your bitmap data is uncompressed, you could probably use this System.Drawing.Bitmap constructor: Bitmap(Int32, Int32, Int32, PixelFormat, IntPtr).

If the bitmap is encoded as jpg or png, create a MemoryStream from the bitmap data, and use it with the Bitmap(Stream) constructor.

EDIT:

Since you're sending the bitmap to a web service, I suggest you encode it to begin with. There are several encoders in the System.Windows.Media.Imaging namespace. For example:

    WriteableBitmap bitmap = ...;
    var stream = new MemoryStream();               
    var encoder = new JpegBitmapEncoder(); 
    encoder.Frames.Add( BitmapFrame.Create( bitmap ) ); 
    encoder.Save( stream ); 
    byte[] buffer = stream.GetBuffer(); 
    // Send the buffer to the web service   

On the receiving end, simply:

    var bitmap = new System.Drawing.Bitmap( new MemoryStream( buffer ) );

Hope that helps.