由于微信发图片有大小限制，用Photoshop转换倒是可以做到把图片缩小，但操作起来比较麻烦，所以自己动手用Java写了个小程序，以减少帧数的方式把动态图片压缩，这方法适用于帧数比较多的gif图片。

    在写这个程序之前百度过能完成编辑图片的几个比较有名的Java库，最终使用了Gif4J，感觉这个比较简单，下面是目录结构

    因为是即兴之作，所以也命名方式不够严谨，请见谅，源码可以在本人的github上面下载https://github.com/yesqwang/GitEditor.git

    UI及程序入口代码 MainUI.java

package gif.ui;import gif.function.Edit;import java.awt.BorderLayout;import java.awt.FlowLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.io.File;import java.io.FileFilter;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.JTextField;public class MainUI extends JFrame implements ActionListener{private static final long serialVersionUID = 1L;JTextField path;JLabel label_path;JButton edit;JTextArea area;JScrollPane pane;public MainUI() {super("GIF图片压缩器");init();}/** * 初始化界面 */private void init() {path = new JTextField(20);label_path = new JLabel("图片所在文件夹路径：");edit = new JButton("开始压缩");area = new JTextArea(5, 25);pane = new JScrollPane(area);JPanel north = new JPanel(new FlowLayout());north.add(label_path);north.add(path);north.add(edit);add(north, BorderLayout.NORTH);add(pane, BorderLayout.CENTER);edit.addActionListener(this);setSize(500, 400);setLocationRelativeTo(null);setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);setVisible(true);}public static void main(String[] args) {new MainUI();}/** * 按钮点击事件 */@Overridepublic void actionPerformed(ActionEvent e) {//获取文件路径，并作必要的判断String p = path.getText();File dir = new File(p);if(dir.exists()){area.setText("开始压缩");File[] files = dir.listFiles(new FileFilter() {@Overridepublic boolean accept(File pathname) {return pathname.getName().endsWith(".gif") ? true : false;}});//Edit这个类是自定义的，具体操作可查看这个类的内容Edit edit = new Edit();//由于该目录下可能有不少待转换的gif图片，所以来了个循环判断int failCount = 0;for(File f : files){//edit(file)这个方法在Edit这个类里，具体操作可查看Edit类if(!edit.edit(f)){failCount ++;area.setText(area.getText() + "    GIF图片：" + f.getName() + " 压缩失败！");}else{area.setText(area.getText() + "    GIF图片：" + f.getName() + " 压缩成功，已存入simple目录中！");}pane.repaint();}area.setText(area.getText() + " 全部操作已完成");area.setText(area.getText() + "    成功 " + (files.length - failCount) + " 个文件");area.setText(area.getText() + "    失败 " + failCount + " 个文件");}else{area.setText("文件路径有误，请重新输入！");}}}

图片转换具体代码 Edit.java

package gif.function;import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.List;import com.gif4j.GifDecoder;import com.gif4j.GifEncoder;import com.gif4j.GifFrame;import com.gif4j.GifImage;public class Edit {/** * 图片压缩转换 * @param file gif图片 * @return 转换成功返回true，否则返回false */public boolean edit(File file ){try {long size = file.length();GifImage image = GifDecoder.decode(file);//将File重编码转化为GifImageint imageFrameNumber = image.getNumberOfFrames();//获取gif图片帧数//将图片的每一帧保存入数组中，方便操作GifFrame[] frames = new GifFrame[imageFrameNumber];for(int i = 0; i < imageFrameNumber; i++){frames[i] = image.getFrame(i);}//设置输出路径及输出文件名：当前目录下新建一个simple文件夹，图片名字不变String outPath = file.getParentFile().getPath() + "\simple";String outName = file.getName();//调用自定义方法转换并保存write(frames, size, outPath , outName);return true;} catch (Exception e) {e.printStackTrace();return false;}}//减少帧数并延长剩余帧的播放速度private void write(GifFrame[] images, long size, String outputDir, String outImageName){             try {            int imagePageCount = images.length;            int delay = images[0].getDelay();//获取原图片每一帧的速度            List<GifFrame> imgs = new ArrayList<GifFrame>();                        double frameSize = size * 1.0 / imagePageCount;//计算平均每一帧的大小            int count = (int)(1 * 1024 * 1024 / frameSize);//计算每MB大概有多少帧            int interval = (imagePageCount / count);//计算大概每隔多少帧抽取一帧                        System.out.println(imagePageCount + "帧");            System.out.println(frameSize/1024/1024 + " MB/帧");            System.out.println(count + "帧/Mb");            System.out.println("每间隔" + interval + "帧抽取1帧");            System.out.println("");                        //计算转换后的图片每一帧的速度            delay = (int) (delay * interval);            //开始转换            for(int i = 0; i < imagePageCount; i++){            if(i == 0 || (interval < i && i % interval == 0)){            imgs.add(images[i]);            }            }                       //新建一个图片对象，这个对象保存最终输出的图片            GifImage gifImage = new GifImage();            gifImage.setLoopNumber(0);            //给最终输出的图片对象添加转换切割过后的帧            for (GifFrame f : imgs){            f.setDelay(delay);                gifImage.addGifFrame(f);            }            //输出            File file = new File(outputDir);            if(!file.exists()){            file.mkdirs();            }                        GifEncoder.encode(gifImage, new File(outputDir, outImageName), true);        } catch (IOException e) {            e.printStackTrace();        }}}

https://github.com/yesqwang/GitEditor.gi

https://github.com/yesqwang/GitEditor.git

https://github.com/yesqwang/GitEditor.git