A value converter between bitmap and bitmapsource Inspired by http://www.codeproject.com/Articles/104929/Bitmap-to-BitmapSource and Matt's comment in the article.

WinFormBitmapConverter.cs

public class WinFormBitmapConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            var bitmap = value as Bitmap;

            if (bitmap == null)
            {
                return null;
            }

            try
            {
                using (var memoryStream = new MemoryStream())
                {
                    // You need to specify the image format to fill the stream. 
                    // I'm assuming it is PNG
                    bitmap.Save(memoryStream, ImageFormat.Png);
                    memoryStream.Seek(0, SeekOrigin.Begin);


                    return CreateBitmapSourceFromBitmap(memoryStream);
                }
            }
            catch (Exception)
            {
                return null;
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            throw new NotImplementedException();
        }

        private static BitmapSource CreateBitmapSourceFromBitmap(Stream stream)
        {
            var bitmapDecoder = BitmapDecoder.Create(
                stream,
                BitmapCreateOptions.PreservePixelFormat,
                BitmapCacheOption.OnLoad);

            // This will disconnect the stream from the image completely...
            var writable = new WriteableBitmap(bitmapDecoder.Frames.Single());
            writable.Freeze();

            return writable;
        }
    }