gif图片质量压缩和尺寸压缩

maven依赖：

<dependency>
            <groupId>com.madgag</groupId>
            <artifactId>animated-gif-lib</artifactId>
            <version>1.2</version>
</dependency>

尺寸压缩：

/** * @param imagePath 原图片路径地址，如：F:\\a.png * @param imgStyle 目标文件类型
     * gif类型图片尺寸压缩
     * @param width 目标文件宽
     * @param height 目标文件高
     * @param outputPath 输出文件路径（不带后缀），如：F:\\b，默认与原图片路径相同，为空时将会替代原文
     * @throws IOException
     */
    public static void zoomGifBySize(String imagePath,int width, int height, String outputPath) throws IOException {
        //GIF需要特殊处理
        GifDecoder decoder = new GifDecoder(); int status = decoder.read(imagePath);
        if (status != GifDecoder.STATUS_OK) {
            throw new IOException("read image " + imagePath + " error!");
        }
        //拆分一帧一帧的压缩之后合成
        AnimatedGifEncoder encoder = new AnimatedGifEncoder();
        encoder.start(outputPath);
        encoder.setRepeat(decoder.getLoopCount());
        for (int i = 0; i < decoder.getFrameCount(); i++) {
            encoder.setDelay(decoder.getDelay(i));
            //设置播放延迟时间
            BufferedImage bufferedImage = decoder.getFrame(i);
            //获取每帧BufferedImage流
            BufferedImage zoomImage = new BufferedImage(width, height, bufferedImage.getType());
            Image image = bufferedImage.getScaledInstance(width, height, Image.SCALE_SMOOTH);
            Graphics gc = zoomImage.getGraphics(); gc.setColor(Color.WHITE);
            gc.drawImage(image, 0, 0, null);
            encoder.addFrame(zoomImage);
        }
        encoder.finish();
        File outFile = new File(outputPath);
        BufferedImage image = ImageIO.read(outFile);
        ImageIO.write(image, outFile.getName(), outFile);
    }

质量压缩：

 /**
     * @param imagePath 原图片路径地址，如：F:\\a.png * @param imgStyle 目标文件类型
     * @param quality 输出的图片质量，范围：0.0~1.0，1为最高质量。
     * @param outputPath 输出文件路径（不带后缀），如：F:\\b，默认与原图片路径相同，为空时将会替代原文件
     * @throws IOException
     */
    public void zoomGifByQuality(String imagePath, float quality, String outputPath) throws IOException { 
        //GIF需要特殊处理
        GifDecoder decoder = new GifDecoder();
        int status = decoder.read(imagePath);
        if (status != GifDecoder.STATUS_OK) {
            throw new IOException("read image " + imagePath + " error!");
        }
        //拆分一帧一帧的压缩之后合成
        AnimatedGifEncoder encoder = new AnimatedGifEncoder();
        encoder.start(outputPath);
        //设置合成位置
        encoder.setRepeat(decoder.getLoopCount());
        //设置GIF重复次数
        int frameCount = decoder.getFrameCount();
        //获取GIF有多少个frame
        for (int i = 0; i < frameCount; i++) {
            encoder.setDelay(decoder.getDelay(i));
            //设置GIF延迟时间
            BufferedImage bufferedImage = decoder.getFrame(i);
            //利用java SDK压缩BufferedImage
            byte[] tempByte = zoomBufferedImageByQuality(bufferedImage, quality, outputPath);
            ByteArrayInputStream in = new ByteArrayInputStream(tempByte);
            BufferedImage zoomImage = ImageIO.read(in);
            encoder.addFrame(zoomImage);// 合成
        }
        encoder.finish();
        File outFile = new File(outputPath);
        BufferedImage image = ImageIO.read(outFile);
        ImageIO.write(image, outFile.getName(), outFile);
    }
    /**
     * 压缩gif
     * @param bufferedImage
     * @param quality
     * @param path
     * @return
     * @throws IOException
     */
    public byte[] zoomBufferedImageByQuality(BufferedImage bufferedImage, float quality, String path) throws IOException {
        // 得到指定Format图片的writer
        Iterator<ImageWriter> iter = ImageIO.getImageWritersByFormatName("jpeg");// 得到迭代器
        ImageWriter writer = (ImageWriter) iter.next(); // 得到writer
        // 得到指定writer的输出参数设置(ImageWriteParam)
        ImageWriteParam iwp = writer.getDefaultWriteParam();
        iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT); // 设置可否压缩
        iwp.setCompressionQuality(quality); // 设置压缩质量参数，0~1，1为最高质量
        iwp.setProgressiveMode(ImageWriteParam.MODE_DISABLED);
        ColorModel colorModel = ColorModel.getRGBdefault();
        // 指定压缩时使用的色彩模式
        iwp.setDestinationType(new ImageTypeSpecifier(colorModel, colorModel.createCompatibleSampleModel(16, 16)));
        // 开始打包图片，写入byte[]
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); // 取得内存输出流
        IIOImage iIamge = new IIOImage(bufferedImage, null, null);
        // 此处因为ImageWriter中用来接收write信息的output要求必须是ImageOutput
        // 通过ImageIo中的静态方法，得到byteArrayOutputStream的ImageOutput
        writer.setOutput(ImageIO.createImageOutputStream(byteArrayOutputStream));
        writer.write(null, iIamge, iwp);
        // 获取压缩后的btye
        byte[] tempByte = byteArrayOutputStream.toByteArray();
        // 创建输出文件，outputPath输出文件路径，imgStyle目标文件格式（png）
        File outFile = new File(path);
        FileOutputStream fos = new FileOutputStream(outFile);
        fos.write(tempByte);
        fos.close();
        return tempByte;
    }