public static void main(String[] args) {
   /*这儿填写你存放要缩小图片的文件夹全地址*/
  String src = " c:/5.gif" ;
  /*这儿填写你转化后的图片存放的文件夹*/
  String tar = " c:/5_frame_2.jpg";
//  获取GIF图片一帧图片
  getGifOneFrame(src, tar, 2);
 }

FileImageInputStream in = null;
FileImageOutputStream out = null;
try {
 in = new FileImageInputStream(new File(src));
 ImageReaderSpi readerSpi = new GIFImageReaderSpi();
 GIFImageReader gifReader = (GIFImageReader) readerSpi.createReaderInstance();
 gifReader.setInput(in);
 int num = gifReader.getNumImages(true);
// 要取的帧数要小于总帧数
 if (num > frame) {
  ImageWriterSpi writerSpi = new GIFImageWriterSpi();
  GIFImageWriter writer = (GIFImageWriter) writerSpi.createWriterInstance();
  for (int i = 0; i < num; i++) {
   if (i == frame) {
    File newfile = new File(target);
    out = new FileImageOutputStream(newfile);
    writer.setOutput(out);
//    读取读取帧的图片
    writer.write(gifReader.read(i));
    return true;
   }
  }
 }

public static void main(String[] args) throws Exception {

 String src = "c:/test2.gif";
 String target = "c:/test2_frame_1.jpg";

 getGifOneFrame(src, target, 1);

 System.out.println("完成");
}

/**
  * 获取GIF图片一帧图片 - 同步执行
  * @param src  源图片路径
  * @param target 目标图片路径
  * @param frame  获取第几帧
  * @throws Exception
  */
 public static boolean getGifOneFrame(String src, String target, int frame) throws Exception {
  if(!src.endsWith(".gif")){
   return false;
  }
  createDirectory(target);
  IMOperation op = new IMOperation();
  op.addImage(src + "["+frame+"]");
  op.addImage(target);
  ConvertCmd cmd = (ConvertCmd) getImageCommand("convert");
  cmd.setAsyncMode(false);
  cmd.run(op);
  return true;
 }