DrawImage filtering when drawing rotated image on WPF DrawingContext

Question

I'm drawing an image on a control, rotated typically just a few degrees. This makes proper filtering important, but I am seeing artifacts that look like a nearest neighbor issue. Where can I set the filter to use when drawing the image?

The image is larger than the resulting size on the screen.

    private void drawRotatedImage( DrawingContext dc , double width_px , double x , double y , double angle )
    {
        dc.PushTransform( new TranslateTransform(x,y) );
        dc.PushTransform( new RotateTransform(angle) );
        double scale = width_px / image.Width;
        Rect rr = new Rect( -image.Width*0.5*scale , -image.Height*0.5*scale , image.Width*scale , image.Height*scale );
        dc.DrawImage( image , rr );
        dc.Pop();
        dc.Pop();
    }

score 0 · Answer 1 · answered Jul 27 '12 at 19:07

If you're writing your code in .NET 4 then you need to up the filter to the higher quality Fant one.

Do that by putting an attached property on your Window or specific element.

DrawImage filtering when drawing rotated image on WPF DrawingContext

1 Answers1