Java、JFrame制作录制GIF小工具

和截屏工具类似,选取一块区域截图保存成图片,gif录制就是选取一块区域持续录制,最后保存成gif动画图片。


运行效果

1、选取需要录制的区域(鼠标拖拽选择录制的区域)
Java、JFrame制作录制GIF小工具_第1张图片

2、点击开始按钮开始录制GIF图片(开始录制时,区域边框会闪烁)
Java、JFrame制作录制GIF小工具_第2张图片

3、点击结束按钮保存GIF图片(没错提示就是这么裸露,自己懒得优化)
Java、JFrame制作录制GIF小工具_第3张图片

4、最后生成GIF图片
Java、JFrame制作录制GIF小工具_第4张图片

设计思路

1、如何绘制矩形区域

如何绘制用户可见的矩形区域,这是一个小的难点,你可以在JFrame绘制任意的形状,如何不遮挡屏幕的情况下,再屏幕任何地方选取一块区域呢

a、首先画一个和屏幕一样大的透明JFrame。
Java、JFrame制作录制GIF小工具_第5张图片

来看下上面的一段代码,是显示一个和电脑屏幕一样大的透明窗口
// 设置窗口无标题部分
this.setUndecorated(true);
// 设置透明背景色,0x01000000 ,01表示透明度
// 这里要注意,不能将窗口设置为00(完全透明),如果设置为完全透明,鼠标将无法聚焦当前窗口,也就无法绘制图形了,这里你可以改成00试试看你就明白了。
this.setBackground(new Color(0x01000000, true));

b、 再监听鼠标拖拽事件,画矩形
Java、JFrame制作录制GIF小工具_第6张图片

上面代码就是画一个矩形,是通过设置label的边框、大小和起点位置来画矩形的

if (sx == -1) // sx=-1说明是鼠标第一次按下,设置label的位置,也就是矩形的位置

else // 否则是鼠标按下拖拽的过程,只需要设置label的大小即可形成一个绘制矩形的效果

选取矩形区域这里有个BUG,用了你就知道了,懒得改 :)

2、截屏

这个录gif不是说选取区域之后就开始录制了,而是先不停的截取区域的图片保存到临时路径下。

Java、JFrame制作录制GIF小工具_第7张图片

上图代码就是每隔interval毫秒截取屏幕并保存为图片的,截屏保存图片的代码很简单,自己稍微看下就明白了。
这里有个需要注意的地方就是,截取的屏幕是不含鼠标的。但是截图没有鼠标就算了,gif图片肯定记录操作的,没有鼠标怎么行。这里的处理是:每次截屏的时候获取鼠标位置信息,在鼠标所在的位置绘制一个小圆圈即可,如下图代码。
Java、JFrame制作录制GIF小工具_第8张图片

3、保存GIF

保存GIF就比较简单了,网上找的一个GIF工具类AnimatedGifEncoder,不知道哪位大神写的。
Java、JFrame制作录制GIF小工具_第9张图片


代码

大家可以下载源代码,不要积分的
http://download.csdn.net/detail/dingyi4815313/9776746

主界面:GIFCapture.java

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Insets;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.io.File;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.UIManager;
import javax.swing.border.LineBorder;
import javax.swing.filechooser.FileSystemView;

/**
 * 屏幕GIF动画录制,有两个较大的问题可以优化(1、保存GIF图片的时间太长。2、保存GIF图片太大),如果你有好的建议可以加QQ294618814,一起探讨
 * 
 * @author ding.yi 2017年3月10日 上午10:20:36
 *
 */
@SuppressWarnings("serial")
public class GIFCapture extends JFrame {

    Toolkit toolkit = Toolkit.getDefaultToolkit();
    Dimension screenSize = toolkit.getScreenSize();
    JLabel label = new JLabel();
    JButton startBtn = new JButton("开始");
    JButton existBtn = new JButton("取消");
    Boolean isRecording = false;
    Rectangle rectangle = null;
    // 临时文件存放的路径
    String tempFilePath = "C:/Windows/temp/java_capture/";
    // 没帧间隔时间(ms),100MS就是说1秒钟10张图片
    int interval = 100;

    public GIFCapture() {

        setLayout(null);

        label.setName("black");
        label.setVisible(false);
        label.setBorder(new LineBorder(Color.black, 4));
        label.setBackground(new Color(0x00000000, true));
        this.add(label);

        // 开始和取消按钮
        startBtn.setMargin(new Insets(0, 0, 0, 0));
        existBtn.setMargin(new Insets(0, 0, 0, 0));
        startBtn.setSize(50, 24);
        existBtn.setSize(50, 24);
        startBtn.setVisible(false);
        existBtn.setVisible(false);
        existBtn.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                dispose();
                System.exit(0);
            }
        });
        startBtn.addActionListener(recordListener);
        this.add(startBtn);
        this.add(existBtn);

        // 窗口属性设置
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.setSize(screenSize);
        this.setUndecorated(true);
        this.setBackground(new Color(0x01000000, true));
        this.setVisible(true);
        this.setAlwaysOnTop(true);

        // 键盘事件,按Esc键可以推出程序
        this.addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                if (e.getKeyCode() == 27) {
                    dispose();
                    System.exit(0);
                }
            }
        });
        this.addMouseMotionListener(ml);
    }

    int sx = -1, sy = -1, cx = -1, cy = -1;
    boolean isDrag = false;
    MouseMotionListener ml = new MouseMotionListener() {
        @Override
        public void mouseMoved(MouseEvent e) {
            if (Math.abs(sx - cx) > 0 && Math.abs(sy - cy) > 0) {
                startBtn.setLocation(cx - startBtn.getWidth(), cy);
                existBtn.setLocation(cx - startBtn.getWidth() - existBtn.getWidth(), cy);
                startBtn.setVisible(true);
                existBtn.setVisible(true);
                rectangle = new Rectangle(sx + 4, sy + 4, Math.abs(sx - cx) - 8, Math.abs(sy - cy) - 8);

                sx = -1;
                sy = -1;
                cx = -1;
                cy = -1;
            }
        }

        @Override
        public void mouseDragged(MouseEvent e) {
            if (isRecording) {
                return;
            }
            if (sx == -1) {
                sx = e.getX();
                sy = e.getY();
                startBtn.setVisible(false);
                label.setSize(0, 0              );
                label.setLocation(sx, sy);
            } else {
                cx = e.getX();
                cy = e.getY();
                label.setSize(Math.abs(sx - cx), Math.abs(sy - cy));
                label.setVisible(true);
            }
            repaint();
        }
    };

    ActionListener recordListener = new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            isRecording = "开始".contentEquals(startBtn.getText());
            if (isRecording) {
                setBackground(new Color(0x00000000, true));
                startBtn.setText("结束");
                existBtn.setVisible(false);
                startRecording();
            } else {
                existBtn.setVisible(false);
                startBtn.setVisible(false);
            }
        }
    };

    protected void startRecording() {
        File f = new File(tempFilePath);
        if (!f.exists()) {
            f.mkdirs();
        }

        // 先将临时文件夹中的截图全部删除
        for (File img : f.listFiles()) {
            img.delete();
        }

        // 开始录制,闪烁边框
        new Thread(new BlinkRunnable()).start();

        // 开始录制,先将截屏一张一张保存到临时文件夹下
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    while (isRecording) {
                        creater(); // 开启线程单独截屏
                        Thread.sleep(interval);
                    }
                    ScreenCapture.saveScreen(rectangle, tempFilePath + System.nanoTime() + ".xy");
                    saveGIF();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }

            /**
             * Q: 这里为何要单独开启线程截屏?
             * A: 只为了保证没帧的间隔时间一样,因为截屏需要一点时间,不开启线程截屏会导致gif动画变快
             */
            private void creater() {
                new Thread(new Runnable() {
                    @Override
                    public void run() {
                        ScreenCapture.saveScreen(rectangle, tempFilePath + System.nanoTime() + ".xy");
                    }
                }).start();
            }

            /**
             * 开始将截屏图片保存为GIF图片,
             */
            private void saveGIF() {
                label.setBackground(Color.gray);
                label.setBorder(new LineBorder(Color.black, 2));
                label.setSize(400, 60);
                label.setText("正在保存图片,请稍等...");
                label.setFont(new Font("宋体", Font.BOLD, 20));

                System.out.println("正在保存GIF图片...");
                // GIF图片保存路径默认为桌面,没有提供选择保存路径界面,可以优化
                String desktopPath = FileSystemView.getFileSystemView().getHomeDirectory() + "/";
                ScreenCapture.createGIF(tempFilePath, desktopPath + "JAVA截图" + System.currentTimeMillis() + ".GIF", interval);
                System.out.println("完成");
                dispose();
                System.exit(0);
            }
        }).start();
    }

    /**
     * 窗口闪烁效果
     */
    class BlinkRunnable implements Runnable {
        @Override
        public void run() {
            while (true) {
                try {
                    // isRecording为false表示没有录制,就一直等待
                    if (!isRecording) {
                        Thread.sleep(100);
                        continue;
                    }

                    // 来切换边框的颜色 黑红黑红的闪烁,表示正在录制
                    Color color = null;

                    if ("black".equals(label.getName())) {
                        color = Color.red;
                        label.setName("red");
                    } else {
                        color = Color.black;
                        label.setName("black");
                    }
                    label.setBorder(new LineBorder(color, 4));

                    Thread.sleep(800);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }

    }

    public static void main(String[] args) throws Exception {
        UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        new GIFCapture();
    }

}

自己封装的截屏工具类:ScreenCapture.java

import java.awt.AWTException;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.MouseInfo;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.imageio.ImageIO;

import com.test.lib.AnimatedGifEncoder;

/**
 * 屏幕截取工具
 * 
 * @author ding.yi 2017年3月10日 上午11:17:45
 *
 */
public class ScreenCapture {

    static List captureBuffList = new ArrayList();

    /**
     * 通过坐标和大小截取屏幕,得到BufferedImage
     * @param x 截屏起点坐标x
     * @param y 截屏起点坐标y
     * @param w 宽度
     * @param h 高度
     * @return BufferedImage
     */
    public static BufferedImage getScreen(int x, int y, int w, int h) {
        Rectangle rect = new Rectangle(x, y, w, h);
        BufferedImage captureImg = null;
        Point p = MouseInfo.getPointerInfo().getLocation();

        try {
            captureImg = new Robot().createScreenCapture(rect);

            // 这里截屏的时候花了一个红圆圈,标识鼠标所在的位置,也可以换成一个鼠标央视的图片
            // 是为了制作gif动画用的,如果是单纯的截屏就不需要
            Graphics g = captureImg.getGraphics();
            g.setColor(Color.red);
            g.fillArc(p.x - x, p.y - y, 15, 15, 0, 360);
        } catch (AWTException e) {
            e.printStackTrace();
        }
        return captureImg;
    }

    public static void saveScreen(Rectangle rect, String savePath) {
        saveScreen(rect.x, rect.y, rect.width, rect.height, savePath);
    }

    public static void saveScreen(Rectangle rect) {
        BufferedImage captureImg = getScreen(rect.x, rect.y, rect.width, rect.height);
        captureBuffList.add(captureImg);
    }

    public static void createGIF(String gifPath, int interval) {
        try {
            AnimatedGifEncoder e = new AnimatedGifEncoder();
            e.setRepeat(0);
            e.start(gifPath);
            for (BufferedImage bufferedImage : captureBuffList) {
                e.setDelay(interval);下·
                e.addFrame(bufferedImage);
            }
            e.finish();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            captureBuffList.clear();
        }
    }

    /**
     * 保存截屏
     * @param x 截屏x坐标
     * @param y 截屏y坐标
     * @param w 截屏宽度
     * @param h 截屏高度
     * @param savePath 截屏图片保存位置
     */
    public static void saveScreen(int x, int y, int w, int h, String savePath) {
        BufferedImage captureImg = getScreen(x, y, w, h);
        File saveFile = new File(savePath);

        if (!saveFile.getParentFile().exists()) {
            saveFile.mkdirs();
        }

        try {
            ImageIO.write(captureImg, "PNG", saveFile);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 将文件夹中的所有图片制作成GIF图片,GIF图片制作的方法是从网上找来的(AnimatedGifEncoder、LZWEncoder和NeuQuant三个类)。
     * @param folderPath    帧图片所在文件夹
     * @param gifPath       保存的GIF图片路径
     * @param interval      没帧间隔(毫秒)
     */
    public static void createGIF(String folderPath, String gifPath, int interval) {
        File[] pic = new File(folderPath).listFiles();
        try {
            AnimatedGifEncoder e = new AnimatedGifEncoder();
            e.setRepeat(0);
            e.start(gifPath);
            BufferedImage src[] = new BufferedImage[pic.length];
            for (int i = 0; i < src.length; i++) {
                e.setDelay(interval); // 设置播放的延迟时间
                src[i] = ImageIO.read(pic[i]); // 读入需要播放的jpg文件
                e.addFrame(src[i]); // 添加到帧中
            }
            e.finish();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) throws InterruptedException {
        for (int i = 1; i <= 100; i++) {
            final int j = i;
            new Thread(new Runnable() {
                @Override
                public void run() {
                    saveScreen(0, 0, 1069, 746, "F:/a/" + (j < 10 ? "0" : "") + j + ".png");
                }
            }).start();
            Thread.sleep(100);
        }
        createGIF("F:/a/", "F:/a/gif.gif", 100);
    }

}

GIF工具类,一共三个

NeuQuant.java

public class NeuQuant {
    protected static final int netsize = 256; /* number of colours used */
    /* four primes near 500 - assume no image has a length so large */
    /* that it is divisible by all four primes */
    protected static final int prime1 = 499;
    protected static final int prime2 = 491;
    protected static final int prime3 = 487;
    protected static final int prime4 = 503;
    protected static final int minpicturebytes = (3 * prime4);
    /* minimum size for input image */
    /*
     * Program Skeleton ---------------- [select samplefac in range 1..30] [read
     * image from input file] pic = (unsigned char*) malloc(3*width*height);
     * initnet(pic,3*width*height,samplefac); learn(); unbiasnet(); [write
     * output image header, using writecolourmap(f)] inxbuild(); write output
     * image using inxsearch(b,g,r)
     */
    /*
     * Network Definitions -------------------
     */
    protected static final int maxnetpos = (netsize - 1);
    protected static final int netbiasshift = 4; /* bias for colour values */
    protected static final int ncycles = 100; /* no. of learning cycles */
    /* defs for freq and bias */
    protected static final int intbiasshift = 16; /* bias for fractions */
    protected static final int intbias = (((int) 1) << intbiasshift);
    protected static final int gammashift = 10; /* gamma = 1024 */
    protected static final int gamma = (((int) 1) << gammashift);
    protected static final int betashift = 10;
    protected static final int beta = (intbias >> betashift); /*
                                                                 * beta = 1/1024
                                                                 */
    protected static final int betagamma = (intbias << (gammashift - betashift));
    /* defs for decreasing radius factor */
    protected static final int initrad = (netsize >> 3); /*
                                                             * for 256 cols, radius
                                                             * starts
                                                             */
    protected static final int radiusbiasshift = 6; /*
                                                     * at 32.0 biased by 6 bits
                                                     */
    protected static final int radiusbias = (((int) 1) << radiusbiasshift);
    protected static final int initradius = (initrad
            * radiusbias); /* and decreases by a */
    protected static final int radiusdec = 30; /* factor of 1/30 each cycle */
    /* defs for decreasing alpha factor */
    protected static final int alphabiasshift = 10; /* alpha starts at 1.0 */
    protected static final int initalpha = (((int) 1) << alphabiasshift);
    protected int alphadec; /* biased by 10 bits */
    /* radbias and alpharadbias used for radpower calculation */
    protected static final int radbiasshift = 8;
    protected static final int radbias = (((int) 1) << radbiasshift);
    protected static final int alpharadbshift = (alphabiasshift + radbiasshift);
    protected static final int alpharadbias = (((int) 1) << alpharadbshift);
    /*
     * Types and Global Variables --------------------------
     */
    protected byte[] thepicture; /* the input image itself */
    protected int lengthcount; /* lengthcount = H*W*3 */
    protected int samplefac; /* sampling factor 1..30 */
    // typedef int pixel[4]; /* BGRc */
    protected int[][] network; /* the network itself - [netsize][4] */
    protected int[] netindex = new int[256];
    /* for network lookup - really 256 */
    protected int[] bias = new int[netsize];
    /* bias and freq arrays for learning */
    protected int[] freq = new int[netsize];
    protected int[] radpower = new int[initrad];

    /* radpower for precomputation */
    /*
     * Initialise network in range (0,0,0) to (255,255,255) and set parameters
     * -----------------------------------------------------------------------
     */
    public NeuQuant(byte[] thepic, int len, int sample) {
        int i;
        int[] p;
        thepicture = thepic;
        lengthcount = len;
        samplefac = sample;
        network = new int[netsize][];
        for (i = 0; i < netsize; i++) {
            network[i] = new int[4];
            p = network[i];
            p[0] = p[1] = p[2] = (i << (netbiasshift + 8)) / netsize;
            freq[i] = intbias / netsize; /* 1/netsize */
            bias[i] = 0;
        }
    }

    public byte[] colorMap() {
        byte[] map = new byte[3 * netsize];
        int[] index = new int[netsize];
        for (int i = 0; i < netsize; i++)
            index[network[i][3]] = i;
        int k = 0;
        for (int i = 0; i < netsize; i++) {
            int j = index[i];
            map[k++] = (byte) (network[j][0]);
            map[k++] = (byte) (network[j][1]);
            map[k++] = (byte) (network[j][2]);
        }
        return map;
    }

    /*
     * Insertion sort of network and building of netindex[0..255] (to do after
     * unbias)
     * -------------------------------------------------------------------------
     * ------
     */
    public void inxbuild() {
        int i, j, smallpos, smallval;
        int[] p;
        int[] q;
        int previouscol, startpos;
        previouscol = 0;
        startpos = 0;
        for (i = 0; i < netsize; i++) {
            p = network[i];
            smallpos = i;
            smallval = p[1]; /* index on g */
            /* find smallest in i..netsize-1 */
            for (j = i + 1; j < netsize; j++) {
                q = network[j];
                if (q[1] < smallval) { /* index on g */
                    smallpos = j;
                    smallval = q[1]; /* index on g */
                }
            }
            q = network[smallpos];
            /* swap p (i) and q (smallpos) entries */
            if (i != smallpos) {
                j = q[0];
                q[0] = p[0];
                p[0] = j;
                j = q[1];
                q[1] = p[1];
                p[1] = j;
                j = q[2];
                q[2] = p[2];
                p[2] = j;
                j = q[3];
                q[3] = p[3];
                p[3] = j;
            }
            /* smallval entry is now in position i */
            if (smallval != previouscol) {
                netindex[previouscol] = (startpos + i) >> 1;
                for (j = previouscol + 1; j < smallval; j++)
                    netindex[j] = i;
                previouscol = smallval;
                startpos = i;
            }
        }
        netindex[previouscol] = (startpos + maxnetpos) >> 1;
        for (j = previouscol + 1; j < 256; j++)
            netindex[j] = maxnetpos; /* really 256 */
    }

    /*
     * Main Learning Loop ------------------
     */
    public void learn() {
        int i, j, b, g, r;
        int radius, rad, alpha, step, delta, samplepixels;
        byte[] p;
        int pix, lim;
        if (lengthcount < minpicturebytes)
            samplefac = 1;
        alphadec = 30 + ((samplefac - 1) / 3);
        p = thepicture;
        pix = 0;
        lim = lengthcount;
        samplepixels = lengthcount / (3 * samplefac);
        delta = samplepixels / ncycles;
        alpha = initalpha;
        radius = initradius;
        rad = radius >> radiusbiasshift;
        if (rad <= 1)
            rad = 0;
        for (i = 0; i < rad; i++)
            radpower[i] = alpha * (((rad * rad - i * i) * radbias) / (rad * rad));
        // fprintf(stderr,"beginning 1D learning: initial radius=%d/n", rad);
        if (lengthcount < minpicturebytes)
            step = 3;
        else if ((lengthcount % prime1) != 0)
            step = 3 * prime1;
        else {
            if ((lengthcount % prime2) != 0)
                step = 3 * prime2;
            else {
                if ((lengthcount % prime3) != 0)
                    step = 3 * prime3;
                else
                    step = 3 * prime4;
            }
        }
        i = 0;
        while (i < samplepixels) {
            b = (p[pix + 0] & 0xff) << netbiasshift;
            g = (p[pix + 1] & 0xff) << netbiasshift;
            r = (p[pix + 2] & 0xff) << netbiasshift;
            j = contest(b, g, r);
            altersingle(alpha, j, b, g, r);
            if (rad != 0)
                alterneigh(rad, j, b, g, r); /* alter neighbours */
            pix += step;
            if (pix >= lim)
                pix -= lengthcount;
            i++;
            if (delta == 0)
                delta = 1;
            if (i % delta == 0) {
                alpha -= alpha / alphadec;
                radius -= radius / radiusdec;
                rad = radius >> radiusbiasshift;
                if (rad <= 1)
                    rad = 0;
                for (j = 0; j < rad; j++)
                    radpower[j] = alpha * (((rad * rad - j * j) * radbias) / (rad * rad));
            }
        }
        // fprintf(stderr,"finished 1D learning: final alpha=%f
        // !/n",((float)alpha)/initalpha);
    }

    /*
     * Search for BGR values 0..255 (after net is unbiased) and return colour
     * index
     * -------------------------------------------------------------------------
     * ---
     */
    public int map(int b, int g, int r) {
        int i, j, dist, a, bestd;
        int[] p;
        int best;
        bestd = 1000; /* biggest possible dist is 256*3 */
        best = -1;
        i = netindex[g]; /* index on g */
        j = i - 1; /* start at netindex[g] and work outwards */
        while ((i < netsize) || (j >= 0)) {
            if (i < netsize) {
                p = network[i];
                dist = p[1] - g; /* inx key */
                if (dist >= bestd)
                    i = netsize; /* stop iter */
                else {
                    i++;
                    if (dist < 0)
                        dist = -dist;
                    a = p[0] - b;
                    if (a < 0)
                        a = -a;
                    dist += a;
                    if (dist < bestd) {
                        a = p[2] - r;
                        if (a < 0)
                            a = -a;
                        dist += a;
                        if (dist < bestd) {
                            bestd = dist;
                            best = p[3];
                        }
                    }
                }
            }
            if (j >= 0) {
                p = network[j];
                dist = g - p[1]; /* inx key - reverse dif */
                if (dist >= bestd)
                    j = -1; /* stop iter */
                else {
                    j--;
                    if (dist < 0)
                        dist = -dist;
                    a = p[0] - b;
                    if (a < 0)
                        a = -a;
                    dist += a;
                    if (dist < bestd) {
                        a = p[2] - r;
                        if (a < 0)
                            a = -a;
                        dist += a;
                        if (dist < bestd) {
                            bestd = dist;
                            best = p[3];
                        }
                    }
                }
            }
        }
        return (best);
    }

    public byte[] process() {
        learn();
        unbiasnet();
        inxbuild();
        return colorMap();
    }

    /*
     * Unbias network to give byte values 0..255 and record position i to
     * prepare for sort
     * -------------------------------------------------------------------------
     * ----------
     */
    public void unbiasnet() {
        int i, j;
        for (i = 0; i < netsize; i++) {
            network[i][0] >>= netbiasshift;
            network[i][1] >>= netbiasshift;
            network[i][2] >>= netbiasshift;
            network[i][3] = i; /* record colour no */
        }
    }

    /*
     * Move adjacent neurons by precomputed alpha*(1-((i-j)^2/[r]^2)) in
     * radpower[|i-j|]
     * -------------------------------------------------------------------------
     * --------
     */
    protected void alterneigh(int rad, int i, int b, int g, int r) {
        int j, k, lo, hi, a, m;
        int[] p;
        lo = i - rad;
        if (lo < -1)
            lo = -1;
        hi = i + rad;
        if (hi > netsize)
            hi = netsize;
        j = i + 1;
        k = i - 1;
        m = 1;
        while ((j < hi) || (k > lo)) {
            a = radpower[m++];
            if (j < hi) {
                p = network[j++];
                try {
                    p[0] -= (a * (p[0] - b)) / alpharadbias;
                    p[1] -= (a * (p[1] - g)) / alpharadbias;
                    p[2] -= (a * (p[2] - r)) / alpharadbias;
                } catch (Exception e) {
                } // prevents 1.3 miscompilation
            }
            if (k > lo) {
                p = network[k--];
                try {
                    p[0] -= (a * (p[0] - b)) / alpharadbias;
                    p[1] -= (a * (p[1] - g)) / alpharadbias;
                    p[2] -= (a * (p[2] - r)) / alpharadbias;
                } catch (Exception e) {
                }
            }
        }
    }

    /*
     * Move neuron i towards biased (b,g,r) by factor alpha
     * ----------------------------------------------------
     */
    protected void altersingle(int alpha, int i, int b, int g, int r) {
        /* alter hit neuron */
        int[] n = network[i];
        n[0] -= (alpha * (n[0] - b)) / initalpha;
        n[1] -= (alpha * (n[1] - g)) / initalpha;
        n[2] -= (alpha * (n[2] - r)) / initalpha;
    }

    /*
     * Search for biased BGR values ----------------------------
     */
    protected int contest(int b, int g, int r) {
        /* finds closest neuron (min dist) and updates freq */
        /* finds best neuron (min dist-bias) and returns position */
        /*
         * for frequently chosen neurons, freq[i] is high and bias[i] is
         * negative
         */
        /* bias[i] = gamma*((1/netsize)-freq[i]) */
        int i, dist, a, biasdist, betafreq;
        int bestpos, bestbiaspos, bestd, bestbiasd;
        int[] n;
        bestd = ~(((int) 1) << 31);
        bestbiasd = bestd;
        bestpos = -1;
        bestbiaspos = bestpos;
        for (i = 0; i < netsize; i++) {
            n = network[i];
            dist = n[0] - b;
            if (dist < 0)
                dist = -dist;
            a = n[1] - g;
            if (a < 0)
                a = -a;
            dist += a;
            a = n[2] - r;
            if (a < 0)
                a = -a;
            dist += a;
            if (dist < bestd) {
                bestd = dist;
                bestpos = i;
            }
            biasdist = dist - ((bias[i]) >> (intbiasshift - netbiasshift));
            if (biasdist < bestbiasd) {
                bestbiasd = biasdist;
                bestbiaspos = i;
            }
            betafreq = (freq[i] >> betashift);
            freq[i] -= betafreq;
            bias[i] += (betafreq << gammashift);
        }
        freq[bestpos] += beta;
        bias[bestpos] -= betagamma;
        return (bestbiaspos);
    }
}

LZWEncoder.java

import java.io.IOException;
import java.io.OutputStream;

//==============================================================================
//  Adapted from Jef Poskanzer's Java port by way of J. M. G. Elliott.
//  K Weiner 12/00
public class LZWEncoder {
    private static final int EOF = -1;
    private int imgW, imgH;
    private byte[] pixAry;
    private int initCodeSize;
    private int remaining;
    private int curPixel;
    // GIFCOMPR.C - GIF Image compression routines
    //
    // Lempel-Ziv compression based on 'compress'. GIF modifications by
    // David Rowley ([email protected])
    // General DEFINEs
    static final int BITS = 12;
    static final int HSIZE = 5003; // 80% occupancy
    // GIF Image compression - modified 'compress'
    //
    // Based on: compress.c - File compression ala IEEE Computer, June 1984.
    //
    // By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
    // Jim McKie (decvax!mcvax!jim)
    // Steve Davies (decvax!vax135!petsd!peora!srd)
    // Ken Turkowski (decvax!decwrl!turtlevax!ken)
    // James A. Woods (decvax!ihnp4!ames!jaw)
    // Joe Orost (decvax!vax135!petsd!joe)
    int n_bits; // number of bits/code
    int maxbits = BITS; // user settable max # bits/code
    int maxcode; // maximum code, given n_bits
    int maxmaxcode = 1 << BITS; // should NEVER generate this code
    int[] htab = new int[HSIZE];
    int[] codetab = new int[HSIZE];
    int hsize = HSIZE; // for dynamic table sizing
    int free_ent = 0; // first unused entry
    // block compression parameters -- after all codes are used up,
    // and compression rate changes, start over.
    boolean clear_flg = false;
    // Algorithm: use open addressing double hashing (no chaining) on the
    // prefix code / next character combination. We do a variant of Knuth's
    // algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
    // secondary probe. Here, the modular division first probe is gives way
    // to a faster exclusive-or manipulation. Also do block compression with
    // an adaptive reset, whereby the code table is cleared when the compression
    // ratio decreases, but after the table fills. The variable-length output
    // codes are re-sized at this point, and a special CLEAR code is generated
    // for the decompressor. Late addition: construct the table according to
    // file size for noticeable speed improvement on small files. Please direct
    // questions about this implementation to ames!jaw.
    int g_init_bits;
    int ClearCode;
    int EOFCode;
    // output
    //
    // Output the given code.
    // Inputs:
    // code: A n_bits-bit integer. If == -1, then EOF. This assumes
    // that n_bits =< wordsize - 1.
    // Outputs:
    // Outputs code to the file.
    // Assumptions:
    // Chars are 8 bits long.
    // Algorithm:
    // Maintain a BITS character long buffer (so that 8 codes will
    // fit in it exactly). Use the VAX insv instruction to insert each
    // code in turn. When the buffer fills up empty it and start over.
    int cur_accum = 0;
    int cur_bits = 0;
    int masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F, 0x003F, 0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF,
            0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };
    // Number of characters so far in this 'packet'
    int a_count;
    // Define the storage for the packet accumulator
    byte[] accum = new byte[256];

    // ----------------------------------------------------------------------------
    LZWEncoder(int width, int height, byte[] pixels, int color_depth) {
        imgW = width;
        imgH = height;
        pixAry = pixels;
        initCodeSize = Math.max(2, color_depth);
    }

    // Add a character to the end of the current packet, and if it is 254
    // characters, flush the packet to disk.
    void char_out(byte c, OutputStream outs) throws IOException {
        accum[a_count++] = c;
        if (a_count >= 254)
            flush_char(outs);
    }

    // Clear out the hash table
    // table clear for block compress
    void cl_block(OutputStream outs) throws IOException {
        cl_hash(hsize);
        free_ent = ClearCode + 2;
        clear_flg = true;
        output(ClearCode, outs);
    }

    // reset code table
    void cl_hash(int hsize) {
        for (int i = 0; i < hsize; ++i)
            htab[i] = -1;
    }

    void compress(int init_bits, OutputStream outs) throws IOException {
        int fcode;
        int i /* = 0 */;
        int c;
        int ent;
        int disp;
        int hsize_reg;
        int hshift;
        // Set up the globals: g_init_bits - initial number of bits
        g_init_bits = init_bits;
        // Set up the necessary values
        clear_flg = false;
        n_bits = g_init_bits;
        maxcode = MAXCODE(n_bits);
        ClearCode = 1 << (init_bits - 1);
        EOFCode = ClearCode + 1;
        free_ent = ClearCode + 2;
        a_count = 0; // clear packet
        ent = nextPixel();
        hshift = 0;
        for (fcode = hsize; fcode < 65536; fcode *= 2)
            ++hshift;
        hshift = 8 - hshift; // set hash code range bound
        hsize_reg = hsize;
        cl_hash(hsize_reg); // clear hash table
        output(ClearCode, outs);
        outer_loop: while ((c = nextPixel()) != EOF) {
            fcode = (c << maxbits) + ent;
            i = (c << hshift) ^ ent; // xor hashing
            if (htab[i] == fcode) {
                ent = codetab[i];
                continue;
            } else if (htab[i] >= 0) // non-empty slot
            {
                disp = hsize_reg - i; // secondary hash (after G. Knott)
                if (i == 0)
                    disp = 1;
                do {
                    if ((i -= disp) < 0)
                        i += hsize_reg;
                    if (htab[i] == fcode) {
                        ent = codetab[i];
                        continue outer_loop;
                    }
                } while (htab[i] >= 0);
            }
            output(ent, outs);
            ent = c;
            if (free_ent < maxmaxcode) {
                codetab[i] = free_ent++; // code -> hashtable
                htab[i] = fcode;
            } else
                cl_block(outs);
        }
        // Put out the final code.
        output(ent, outs);
        output(EOFCode, outs);
    }

    // ----------------------------------------------------------------------------
    void encode(OutputStream os) throws IOException {
        os.write(initCodeSize); // write "initial code size" byte
        remaining = imgW * imgH; // reset navigation variables
        curPixel = 0;
        compress(initCodeSize + 1, os); // compress and write the pixel data
        os.write(0); // write block terminator
    }

    // Flush the packet to disk, and reset the accumulator
    void flush_char(OutputStream outs) throws IOException {
        if (a_count > 0) {
            outs.write(a_count);
            outs.write(accum, 0, a_count);
            a_count = 0;
        }
    }

    final int MAXCODE(int n_bits) {
        return (1 << n_bits) - 1;
    }

    // ----------------------------------------------------------------------------
    // Return the next pixel from the image
    // ----------------------------------------------------------------------------
    private int nextPixel() {
        if (remaining == 0)
            return EOF;
        --remaining;
        byte pix = pixAry[curPixel++];
        return pix & 0xff;
    }

    void output(int code, OutputStream outs) throws IOException {
        cur_accum &= masks[cur_bits];
        if (cur_bits > 0)
            cur_accum |= (code << cur_bits);
        else
            cur_accum = code;
        cur_bits += n_bits;
        while (cur_bits >= 8) {
            char_out((byte) (cur_accum & 0xff), outs);
            cur_accum >>= 8;
            cur_bits -= 8;
        }
        // If the next entry is going to be too big for the code size,
        // then increase it, if possible.
        if (free_ent > maxcode || clear_flg) {
            if (clear_flg) {
                maxcode = MAXCODE(n_bits = g_init_bits);
                clear_flg = false;
            } else {
                ++n_bits;
                if (n_bits == maxbits)
                    maxcode = maxmaxcode;
                else
                    maxcode = MAXCODE(n_bits);
            }
        }
        if (code == EOFCode) {
            // At EOF, write the rest of the buffer.
            while (cur_bits > 0) {
                char_out((byte) (cur_accum & 0xff), outs);
                cur_accum >>= 8;
                cur_bits -= 8;
            }
            flush_char(outs);
        }
    }
}

AnimatedGifEncoder.java

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferByte;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * Class AnimatedGifEncoder - Encodes a GIF file consisting of one or more
 * frames.
 * 
 * 
 * Example:
 *    AnimatedGifEncoder e = new AnimatedGifEncoder();
 *    e.start(outputFileName);
 *    e.setDelay(1000);   // 1 frame per sec
 *    e.addFrame(image1);
 *    e.addFrame(image2);
 *    e.finish();
 * 
* * No copyright asserted on the source code of this class. May be used for any * purpose, however, refer to the Unisys LZW patent for restrictions on use of * the associated LZWEncoder class. Please forward any corrections to * [email protected]. * * @author Kevin Weiner, FM Software * @version 1.03 November 2003 * */
public class AnimatedGifEncoder { protected int width; // image size protected int height; protected Color transparent = null; // transparent color if given protected int transIndex; // transparent index in color table protected int repeat = -1; // no repeat protected int delay = 0; // frame delay (hundredths) protected boolean started = false; // ready to output frames protected OutputStream out; protected BufferedImage image; // current frame protected byte[] pixels; // BGR byte array from frame protected byte[] indexedPixels; // converted frame indexed to palette protected int colorDepth; // number of bit planes protected byte[] colorTab; // RGB palette protected boolean[] usedEntry = new boolean[256]; // active palette entries protected int palSize = 7; // color table size (bits-1) protected int dispose = -1; // disposal code (-1 = use default) protected boolean closeStream = false; // close stream when finished protected boolean firstFrame = true; protected boolean sizeSet = false; // if false, get size from first frame protected int sample = 10; // default sample interval for quantizer /** * Sets the delay time between each frame, or changes it for subsequent * frames (applies to last frame added). * * @param ms * int delay time in milliseconds */ public void setDelay(int ms) { delay = Math.round(ms / 10.0f); } /** * Sets the GIF frame disposal code for the last added frame and any * subsequent frames. Default is 0 if no transparent color has been set, * otherwise 2. * * @param code * int disposal code. */ public void setDispose(int code) { if (code >= 0) { dispose = code; } } /** * Sets the number of times the set of GIF frames should be played. Default * is 1; 0 means play indefinitely. Must be invoked before the first image * is added. * * @param iter * int number of iterations. * @return */ public void setRepeat(int iter) { if (iter >= 0) { repeat = iter; } } /** * Sets the transparent color for the last added frame and any subsequent * frames. Since all colors are subject to modification in the quantization * process, the color in the final palette for each frame closest to the * given color becomes the transparent color for that frame. May be set to * null to indicate no transparent color. * * @param c * Color to be treated as transparent on display. */ public void setTransparent(Color c) { transparent = c; } /** * Adds next GIF frame. The frame is not written immediately, but is * actually deferred until the next frame is received so that timing data * can be inserted. Invoking finish() flushes all frames. If * setSize was not invoked, the size of the first image is used * for all subsequent frames. * * @param im * BufferedImage containing frame to write. * @return true if successful. */ public boolean addFrame(BufferedImage im) { if ((im == null) || !started) { return false; } boolean ok = true; try { if (!sizeSet) { // use first frame's size setSize(im.getWidth(), im.getHeight()); } image = im; getImagePixels(); // convert to correct format if necessary analyzePixels(); // build color table & map pixels if (firstFrame) { writeLSD(); // logical screen descriptior writePalette(); // global color table if (repeat >= 0) { // use NS app extension to indicate reps writeNetscapeExt(); } } writeGraphicCtrlExt(); // write graphic control extension writeImageDesc(); // image descriptor if (!firstFrame) { writePalette(); // local color table } writePixels(); // encode and write pixel data firstFrame = false; } catch (IOException e) { ok = false; } return ok; } /** * Flushes any pending data and closes output file. If writing to an * OutputStream, the stream is not closed. */ public boolean finish() { if (!started) return false; boolean ok = true; started = false; try { out.write(0x3b); // gif trailer out.flush(); if (closeStream) { out.close(); } } catch (IOException e) { ok = false; } // reset for subsequent use transIndex = 0; out = null; image = null; pixels = null; indexedPixels = null; colorTab = null; closeStream = false; firstFrame = true; return ok; } /** * Sets frame rate in frames per second. Equivalent to * setDelay(1000/fps). * * @param fps * float frame rate (frames per second) */ public void setFrameRate(float fps) { if (fps != 0f) { delay = Math.round(100f / fps); } } /** * Sets quality of color quantization (conversion of images to the maximum * 256 colors allowed by the GIF specification). Lower values (minimum = 1) * produce better colors, but slow processing significantly. 10 is the * default, and produces good color mapping at reasonable speeds. Values * greater than 20 do not yield significant improvements in speed. * * @param quality * int greater than 0. * @return */ public void setQuality(int quality) { if (quality < 1) quality = 1; sample = quality; } /** * Sets the GIF frame size. The default size is the size of the first frame * added if this method is not invoked. * * @param w * int frame width. * @param h * int frame width. */ public void setSize(int w, int h) { if (started && !firstFrame) return; width = w; height = h; if (width < 1) width = 320; if (height < 1) height = 240; sizeSet = true; } /** * Initiates GIF file creation on the given stream. The stream is not closed * automatically. * * @param os * OutputStream on which GIF images are written. * @return false if initial write failed. */ public boolean start(OutputStream os) { if (os == null) return false; boolean ok = true; closeStream = false; out = os; try { writeString("GIF89a"); // header } catch (IOException e) { ok = false; } return started = ok; } /** * Initiates writing of a GIF file with the specified name. * * @param file * String containing output file name. * @return false if open or initial write failed. */ public boolean start(String file) { boolean ok = true; try { out = new BufferedOutputStream(new FileOutputStream(file)); ok = start(out); closeStream = true; } catch (IOException e) { ok = false; } return started = ok; } /** * Analyzes image colors and creates color map. */ protected void analyzePixels() { int len = pixels.length; int nPix = len / 3; indexedPixels = new byte[nPix]; NeuQuant nq = new NeuQuant(pixels, len, sample); // initialize quantizer colorTab = nq.process(); // create reduced palette // convert map from BGR to RGB for (int i = 0; i < colorTab.length; i += 3) { byte temp = colorTab[i]; colorTab[i] = colorTab[i + 2]; colorTab[i + 2] = temp; usedEntry[i / 3] = false; } // map image pixels to new palette int k = 0; for (int i = 0; i < nPix; i++) { int index = nq.map(pixels[k++] & 0xff, pixels[k++] & 0xff, pixels[k++] & 0xff); usedEntry[index] = true; indexedPixels[i] = (byte) index; } pixels = null; colorDepth = 8; palSize = 7; // get closest match to transparent color if specified if (transparent != null) { transIndex = findClosest(transparent); } } /** * Returns index of palette color closest to c * */ protected int findClosest(Color c) { if (colorTab == null) return -1; int r = c.getRed(); int g = c.getGreen(); int b = c.getBlue(); int minpos = 0; int dmin = 256 * 256 * 256; int len = colorTab.length; for (int i = 0; i < len;) { int dr = r - (colorTab[i++] & 0xff); int dg = g - (colorTab[i++] & 0xff); int db = b - (colorTab[i] & 0xff); int d = dr * dr + dg * dg + db * db; int index = i / 3; if (usedEntry[index] && (d < dmin)) { dmin = d; minpos = index; } i++; } return minpos; } /** * Extracts image pixels into byte array "pixels" */ protected void getImagePixels() { int w = image.getWidth(); int h = image.getHeight(); int type = image.getType(); if ((w != width) || (h != height) || (type != BufferedImage.TYPE_3BYTE_BGR)) { // create new image with right size/format BufferedImage temp = new BufferedImage(width, height, BufferedImage.TYPE_3BYTE_BGR); Graphics2D g = temp.createGraphics(); g.drawImage(image, 0, 0, null); image = temp; } pixels = ((DataBufferByte) image.getRaster().getDataBuffer()).getData(); } /** * Writes Graphic Control Extension */ protected void writeGraphicCtrlExt() throws IOException { out.write(0x21); // extension introducer out.write(0xf9); // GCE label out.write(4); // data block size int transp, disp; if (transparent == null) { transp = 0; disp = 0; // dispose = no action } else { transp = 1; disp = 2; // force clear if using transparent color } if (dispose >= 0) { disp = dispose & 7; // user override } disp <<= 2; // packed fields out.write(0 | // 1:3 reserved disp | // 4:6 disposal 0 | // 7 user input - 0 = none transp); // 8 transparency flag writeShort(delay); // delay x 1/100 sec out.write(transIndex); // transparent color index out.write(0); // block terminator } /** * Writes Image Descriptor */ protected void writeImageDesc() throws IOException { out.write(0x2c); // image separator writeShort(0); // image position x,y = 0,0 writeShort(0); writeShort(width); // image size writeShort(height); // packed fields if (firstFrame) { // no LCT - GCT is used for first (or only) frame out.write(0); } else { // specify normal LCT out.write(0x80 | // 1 local color table 1=yes 0 | // 2 interlace - 0=no 0 | // 3 sorted - 0=no 0 | // 4-5 reserved palSize); // 6-8 size of color table } } /** * Writes Logical Screen Descriptor */ protected void writeLSD() throws IOException { // logical screen size writeShort(width); writeShort(height); // packed fields out.write((0x80 | // 1 : global color table flag = 1 (gct used) 0x70 | // 2-4 : color resolution = 7 0x00 | // 5 : gct sort flag = 0 palSize)); // 6-8 : gct size out.write(0); // background color index out.write(0); // pixel aspect ratio - assume 1:1 } /** * Writes Netscape application extension to define repeat count. */ protected void writeNetscapeExt() throws IOException { out.write(0x21); // extension introducer out.write(0xff); // app extension label out.write(11); // block size writeString("NETSCAPE" + "2.0"); // app id + auth code out.write(3); // sub-block size out.write(1); // loop sub-block id writeShort(repeat); // loop count (extra iterations, 0=repeat forever) out.write(0); // block terminator } /** * Writes color table */ protected void writePalette() throws IOException { out.write(colorTab, 0, colorTab.length); int n = (3 * 256) - colorTab.length; for (int i = 0; i < n; i++) { out.write(0); } } /** * Encodes and writes pixel data */ protected void writePixels() throws IOException { LZWEncoder encoder = new LZWEncoder(width, height, indexedPixels, colorDepth); encoder.encode(out); } /** * Write 16-bit value to output stream, LSB first */ protected void writeShort(int value) throws IOException { out.write(value & 0xff); out.write((value >> 8) & 0xff); } /** * Writes string to output stream */ protected void writeString(String s) throws IOException { for (int i = 0; i < s.length(); i++) { out.write((byte) s.charAt(i)); } } }

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