解析Gif文件的每一帧为图片文件

方法一
网上下了解析gif的代码，有以下几个类（可以在网上找到）：
AnimatedGifEncoder
GifDecoder
LZWEncoder
NeuQuant

调用的例子：

public static void main(String[] args) throws ImageFormatException,
			IOException {
		GifDecoder d = new GifDecoder();
		d.read("C:\\Users\\rui\\Desktop\\1.gif");
//		d.decodeImageData();
		int n = d.getFrameCount();
		System.out.println(d.gctFlag);
		System.out.println(d.gctSize);
		System.out.println(d.gct);
//		for(int i : d.gct) System.out.println(i);
		for (int i = 0; i < n; i++) {
			BufferedImage frame = d.getFrame(i); // 　frame　i
			
			int t = d.getDelay(i);
			FileOutputStream fos = new FileOutputStream("C:\\Users\\rui\\Desktop\\zrzr\\" + i + ".jpg");
			
			JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(fos);
			encoder.encode(frame);
			fos.close();
		}
	}

问题：
解析出来的图片颜色的怪怪的，背景是红色的...反正和原来看到的gif不一样，找半天原因，可能和 全局色表（global color table）有关，但还没弄明白。

方法二

File file = new File("C:\\Users\\Administrator\\Desktop\\1.gif");
		
		FileImageInputStream in = new FileImageInputStream(file);
		
        //GIFImageReader reader = null;
		ImageReaderSpi readerSpi = new GIFImageReaderSpi();
		
		//readerSpi.canDecodeInput(in);
		
		GIFImageReader gifReader = (GIFImageReader) readerSpi.createReaderInstance();
		
		gifReader.setInput(in);
		
		int num = gifReader.getNumImages(true);
		
		gifReader.getNumImages(true);
		
		System.out.println(num);
		
		ImageWriterSpi writerSpi = new GIFImageWriterSpi();
		
		GIFImageWriter writer = (GIFImageWriter) writerSpi.createWriterInstance();

		for (int i = 0; i < num; i++) {
			
			File newfile = new File("C:\\Users\\Administrator\\Desktop\\zrzr\\"+i+".jpg");
			
			FileImageOutputStream out = new FileImageOutputStream(newfile);
			
			writer.setOutput(out);
			
			writer.write(gifReader.read(i)); 
			
			out.close();
		}