Hvorfor bliver mine billeder grimme?

Jeg vil gerne skalere mine billeder ned uden de bliver grimme. Hvordan skalere jeg unden tab og "klarhed"?

private void DisplayImage( int maxDimension )
{
    string imagePath = MapPath( Album.AlbumImages[ AlbumIndex ][ PictureIndex ] );

    System.Drawing.Image image = new Bitmap( imagePath );
    System.Drawing.Image thumbnail;


    // Make pictures smaller but not larger.
    if( image.PhysicalDimension.Width < maxDimension &&
        image.PhysicalDimension.Height < maxDimension )
    {
        thumbnail = image;
    }
    else
    {
        // Aspect ratio logic provided by Bryce Jasmer.
        float aspect = image.PhysicalDimension.Width / image.PhysicalDimension.Height;
        if ( aspect <= 1.0 ) // Portrait
        {
            thumbnail = image.GetThumbnailImage(
                (int)(maxDimension * aspect), maxDimension, null, new IntPtr());
        }
        else // Landscape
        {
            thumbnail = image.GetThumbnailImage(
                maxDimension, (int)(maxDimension / aspect), null, new IntPtr());
        }
    }
   
    thumbnail.Save( Response.OutputStream, image.);
}