金刚狼2电影:.NET中如何分解和合成Gif图像

一个Gif图像文件，是有几个文件进行合成的，因此处理此类文件的时候，不能像Jpeg或者Bmp文件那样处理。需要把Gif文件拆分帧的形式，然后对每一帧进行处理，处理完后再合成Gif。

其实网上有个例子对于Gif处理非常详细，地址如下。

http://www.codeproject.com/dotnet/NGif.asp

   1: /* create Gif */

   2: //you should replace filepath

   3: String [] imageFilePaths = new String[]{"c:\\01.png","c:\\02.png","c:\\03.png"}; 

   4: String outputFilePath = "c:\\test.gif";

   5: AnimatedGifEncoder e = new AnimatedGifEncoder();

   6: e.Start( outputFilePath );

   7: e.SetDelay(500);

   8: //-1:no repeat,0:always repeat

   9: e.SetRepeat(0);

  10: for (int i = 0, count = imageFilePaths.Length; i < count; i++ ) 

  11: {

  12:  e.AddFrame( Image.FromFile( imageFilePaths[i] ) );

  13: }

  14: e.Finish();

  15: /* extract Gif */

  16: string outputPath = "c:\\";

  17: GifDecoder gifDecoder = new GifDecoder();

  18: gifDecoder.Read( "c:\\test.gif" );

  19: for ( int i = 0, count = gifDecoder.GetFrameCount(); i < count; i++ ) 

  20: {

  21:  Image frame = gifDecoder.GetFrame( i ); // frame i

  22:  frame.Save( outputPath + Guid.NewGuid().ToString() 

  23:                        + ".png", ImageFormat.Png );

  24: }

但是对于一个Gif进行拆分，其实Image对象本身就支持，例如对于一个Gif文件拆分成Jpeg文件方式，可以按照如下的方式进行处理。

   1: using System.Drawing.Drawing2D;

   2:  

   3: using System.Drawing.Imaging;

   4:  

   5: Image imgGif = Image.FromFile(@"d:\test.gif");

   6:  

   7: //Create a new FrameDimension object from this image

   8:  

   9: FrameDimension ImgFrmDim = new FrameDimension( imgGif.FrameDimensionsList[0] );

  10:  

  11: //Determine the number of frames in the image

  12:  

  13: //Note that all images contain at least 1 frame, 

  14:  

  15: //but an animated GIF will contain more than 1 frame.

  16:  

  17: int nFrameCount = imgGif.GetFrameCount( ImgFrmDim );

  18:  

  19: // Save every frame into jpeg format

  20:  

  21: for( int i = 0; i < nFrameCount; i++ )

  22:  

  23: {

  24:  

  25:     imgGif.SelectActiveFrame( ImgFrmDim, i );

  26:  

  27:     imgGif.Save( string.Format( @"d:\Frame{0}.jpg", i ), ImageFormat.Jpeg );

  28:  

  29: }