.Net中使用GDI+提高gif图片画质的代码

system.drawing.bitmap b = new System.Drawing.Bitmap(“c:\original_image.gif“);
System.Drawing.Image thmbnail = b.GetThumbnailImage(100,75,null,new IntPtr());
OctreeQuantizer quantizer = new OctreeQuantizer ( 255 , 8 ) ;
using ( Bitmap quantized = quantizer.Quantize ( thmbnail ) )
{
quantized.Save(“c:\thumnail.gif“, System.Drawing.Imaging.ImageFormat.Gif);
}
octreequantizer grayquantizer = new GrayscaleQuantizer ( ) ;
using ( Bitmap quantized = grayquantizer.Quantize ( thmbnail ) )
{
quantized.Save(“c:\thumnail.gif“, System.Drawing.Imaging.ImageFormat.Gif);
}