public BitmapSource ResizeBitmap( int size )
{
var image = GetBitmapImage();
var scale = new ScaleTransform();
scale.ScaleY = scale.ScaleX = ( image.PixelWidth < image.PixelHeight )
? (double) size / image.PixelWidth
: (double) size / image.PixelHeight;
return new TransformedBitmap( image, scale );
}