semovy

包括四個(gè)類AnimatedGifEncoder.java ,GifDecoder.java , LZWEncoder.java , NeuQuant.java

//AnimatedGifEncoder.java

??? package ip.gif.neuquantAnimation;
????
??? import java.awt.*;
??? 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.
??? * <pre>
??? * Example:
??? *??? AnimatedGifEncoder e = new AnimatedGifEncoder();
??? *??? e.start(outputFileName);
??? *??? e.setDelay(1000);?? // 1 frame per sec
??? *??? e.addFrame(image1);
??? *??? e.addFrame(image2);
??? *??? e.finish();
??? * </pre>
??? * 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 kweiner@fmsware.com.
??? *
??? * @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 = 40; // 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.
??????? */
?????? 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 <code>finish()</code> flushes all
?????? * frames.? If <code>setSize</code> 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 {
????????????? addImage(im);
????????? } catch (IOException e) {
????????????? ok = false;
????????? }
??
????????? return ok;
????? }
??
????? private void addImage(BufferedImage im) throws IOException {
????????? if (!sizeSet) {
????????????? // use first frame's size
????????????? setSize(im.getWidth(), im.getHeight());
????????? }
????????? image = im;
????????? long time = System.currentTimeMillis();
????????? getImagePixels(); // convert to correct format if necessary
????????? //System.out.println("getImagePixels took:"+
????????? //??????? (System.currentTimeMillis()-time)+" ms");
????????? time = System.currentTimeMillis();
????????? analyzePixels(this); // build color table & map pixels
????????? System.out.println("analyzePixels took:" +
????????????????? (System.currentTimeMillis() - time) + " ms");
????????? time = System.currentTimeMillis();
????????? 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;
????????? System.out.println("writing out data took:" +
????????????????? (System.currentTimeMillis() - time) + " ms");
????? }
??
????? /**
?????? * 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
?????? * <code>setDelay(1000/fps)</code>.
?????? *
?????? * @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.
?????? */
????? 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.
?????? * @param animatedGifEncoder
?????? */
????? private static final void analyzePixels(AnimatedGifEncoder
????????????? animatedGifEncoder) {
????????? int len = animatedGifEncoder.pixels.length;
????????? int nPix = len / 3;
????????? animatedGifEncoder.indexedPixels = new byte[nPix];
????????? NeuQuant nq = new NeuQuant(animatedGifEncoder.pixels,
????????????????? len, animatedGifEncoder.sample);
????????? // initialize quantizer
??????
????????? animatedGifEncoder.colorTab = nq.process(); // create reduced palette
??
????????? // convert map from BGR to RGB
????????? byte temp = 0;
????????? for (int i = 0; i < animatedGifEncoder.colorTab.length; i += 3) {
????????????? temp = animatedGifEncoder.colorTab[i];
????????????? animatedGifEncoder.colorTab[i] = animatedGifEncoder.colorTab[i + 2];
????????????? animatedGifEncoder.colorTab[i + 2] = temp;
????????????? animatedGifEncoder.usedEntry[i / 3] = false;
????????? }
????????? // map image pixels to new palette
????????? int k = 0;
????????? int index = 0;
????????? for (int i = 0; i < nPix; i++) {
?????????????? index =
????????????????? nq.map(animatedGifEncoder.pixels[k++] & 0xff,
???????????????????????? animatedGifEncoder.pixels[k++] & 0xff,
???????????????????????? animatedGifEncoder.pixels[k++] & 0xff);
????????????? animatedGifEncoder.usedEntry[index] = true;
????????????? animatedGifEncoder.indexedPixels[i] = (byte) index;
????????? }
????????? animatedGifEncoder.pixels = null;
????????? animatedGifEncoder.colorDepth = 8;
????????? animatedGifEncoder.palSize = 7;
????????? // get closest match to transparent color if specified
????????? if (animatedGifEncoder.transparent != null) {
????????????? animatedGifEncoder.transIndex = findClosest(animatedGifEncoder.colorTab, animatedGifEncoder.usedEntry, animatedGifEncoder.transparent);
????????? }
????? }
??????
????? /**
?????? * Returns index of palette color closest to c
?????? * This is using square error and a search, for each
?????? * color.
?????? * It is not efficient.
?????? * todo: optimize this search
?????? *
?????? */
????? private final static int findClosest(byte[] colorTab1,
??????????????????????????????? boolean[] usedEntry1,
??????????????????????????????? Color c) {
????????? if (colorTab1 == 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 = colorTab1.length;
????????? int dr,dg,db,d,index;
????????? for (int i = 0; i < len;) {
?????????????? dr = r - (colorTab1[i++] & 0xff);
?????????????? dg = g - (colorTab1[i++] & 0xff);
?????????????? db = b - (colorTab1[i] & 0xff);
?????????????? d = dr * dr + dg * dg + db * db;
?????????????? index = i / 3;
????????????? if (usedEntry1[index] && (d < dmin)) {
????????????????? dmin = d;
????????????????? minpos = index;
????????????? }
????????????? i++;
????????? }
????????? return minpos;
????? }
??????
????? /**
?????? * Extracts image pixels into byte array "pixels"
?????? */
????? private final 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
?????? */
????? private final 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));
????????? }
????? }
? }
?

//GifDecoder.java

??? package ip.gif.neuquantAnimation;
????
??? import java.net.*;
??? import java.io.*;
??? import java.util.*;
??? import java.awt.*;
??? import java.awt.image.*;
????
??? /**
??? * Class GifDecoder - Decodes a GIF file into one or more frames.
??? * <br><pre>
??? * Example:
??? *??? GifDecoder d = new GifDecoder();
??? *??? d.read("sample.gif");
??? *??? int n = d.getFrameCount();
??? *??? for (int i = 0; i < n; i++) {
??? *?????? BufferedImage frame = d.getFrame(i);? // frame i
??? *?????? int t = d.getDelay(i);? // display duration of frame in milliseconds
??? *?????? // do something with frame
??? *??? }
??? * </pre>
??? * No copyright asserted on the source code of this class.? May be used for
??? * any purpose, however, refer to the Unisys LZW patent for any additional
??? * restrictions.? Please forward any corrections to kweiner@fmsware.com.
??? *
??? * @author Kevin Weiner, FM Software; LZW decoder adapted from John Cristy's ImageMagick.
??? * @version 1.03 November 2003
??? *
??? */
???
?? public class GifDecoder {
???
?????? /**
??????? * File read status: No errors.
??????? */
?????? public static final int STATUS_OK = 0;
???
?????? /**
??????? * File read status: Error decoding file (may be partially decoded)
??????? */
?????? public static final int STATUS_FORMAT_ERROR = 1;
???
?????? /**
??????? * File read status: Unable to open source.
??????? */
?????? public static final int STATUS_OPEN_ERROR = 2;
???
?????? protected BufferedInputStream in;
?????? protected int status;
???
?????? protected int width; // full image width
?????? protected int height; // full image height
?????? protected boolean gctFlag; // global color table used
?????? protected int gctSize; // size of global color table
?????? protected int loopCount = 1; // iterations; 0 = repeat forever
???
?????? protected int[] gct; // global color table
?????? protected int[] lct; // local color table
?????? protected int[] act; // active color table
???
?????? protected int bgIndex; // background color index
?????? protected int bgColor; // background color
?????? protected int lastBgColor; // previous bg color
?????? protected int pixelAspect; // pixel aspect ratio
???
?????? protected boolean lctFlag; // local color table flag
?????? protected boolean interlace; // interlace flag
?????? protected int lctSize; // local color table size
???
?????? protected int ix, iy, iw, ih; // current image rectangle
?????? protected Rectangle lastRect; // last image rect
?????? protected BufferedImage image; // current frame
?????? protected BufferedImage lastImage; // previous frame
???
?????? protected byte[] block = new byte[256]; // current data block
?????? protected int blockSize = 0; // block size
???
?????? // last graphic control extension info
?????? protected int dispose = 0;
?????? // 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
?????? protected int lastDispose = 0;
?????? protected boolean transparency = false; // use transparent color
?????? protected int delay = 0; // delay in milliseconds
?????? protected int transIndex; // transparent color index
???
?????? protected static final int MaxStackSize = 4096;
?????? // max decoder pixel stack size
???
?????? // LZW decoder working arrays
?????? protected short[] prefix;
?????? protected byte[] suffix;
?????? protected byte[] pixelStack;
?????? protected byte[] pixels;
???
?????? protected ArrayList frames; // frames read from current file
?????? protected int frameCount;
???
?????? static class GifFrame {
?????????? public GifFrame(BufferedImage im, int del) {
????????????? image = im;
????????????? delay = del;
????????? }
????????? public BufferedImage image;
????????? public int delay;
????? }
??
????? /**
?????? * Gets display duration for specified frame.
?????? *
?????? * @param n int index of frame
?????? * @return delay in milliseconds
?????? */
????? public int getDelay(int n) {
????????? //
????????? delay = -1;
????????? if ((n >= 0) && (n < frameCount)) {
????????????? delay = ((GifFrame) frames.get(n)).delay;
????????? }
????????? return delay;
????? }
??
????? /**
?????? * Gets the number of frames read from file.
?????? * @return frame count
?????? */
????? public int getFrameCount() {
????????? return frameCount;
????? }
??
????? /**
?????? * Gets the first (or only) image read.
?????? *
?????? * @return BufferedImage containing first frame, or null if none.
?????? */
????? public BufferedImage getImage() {
????????? return getFrame(0);
????? }
??
????? /**
?????? * Gets the "Netscape" iteration count, if any.
?????? * A count of 0 means repeat indefinitiely.
?????? *
?????? * @return iteration count if one was specified, else 1.
?????? */
????? public int getLoopCount() {
????????? return loopCount;
????? }
??
????? /**
?????? * Creates new frame image from current data (and previous
?????? * frames as specified by their disposition codes).
?????? */
????? protected void setPixels() {
????????? // expose destination image's pixels as int array
????????? int[] dest =
????????????? ((DataBufferInt) image.getRaster().getDataBuffer()).getData();
??
????????? // fill in starting image contents based on last image's dispose code
????????? if (lastDispose > 0) {
????????????? if (lastDispose == 3) {
????????????????? // use image before last
????????????????? int n = frameCount - 2;
????????????????? if (n > 0) {
????????????????????? lastImage = getFrame(n - 1);
????????????????? } else {
????????????????????? lastImage = null;
????????????????? }
????????????? }
??
????????????? if (lastImage != null) {
????????????????? int[] prev =
????????????????????? ((DataBufferInt) lastImage.getRaster().getDataBuffer()).getData();
????????????????? System.arraycopy(prev, 0, dest, 0, width * height);
????????????????? // copy pixels
??
????????????????? if (lastDispose == 2) {
????????????????????? // fill last image rect area with background color
????????????????????? Graphics2D g = image.createGraphics();
????????????????????? Color c = null;
????????????????????? if (transparency) {
????????????????????????? c = new Color(0, 0, 0, 0);? // assume background is transparent
????????????????????? } else {
????????????????????????? c = new Color(lastBgColor); // use given background color
????????????????????? }
????????????????????? g.setColor(c);
????????????????????? g.setComposite(AlphaComposite.Src); // replace area
????????????????????? g.fill(lastRect);
????????????????????? g.dispose();
????????????????? }
????????????? }
????????? }
??
????????? // copy each source line to the appropriate place in the destination
????????? int pass = 1;
????????? int inc = 8;
????????? int iline = 0;
????????? for (int i = 0; i < ih; i++) {
????????????? int line = i;
????????????? if (interlace) {
????????????????? if (iline >= ih) {
????????????????????? pass++;
????????????????????? switch (pass) {
????????????????????????? case 2 :
????????????????????????????? iline = 4;
????????????????????????????? break;
????????????????????????? case 3 :
????????????????????????????? iline = 2;
????????????????????????????? inc = 4;
????????????????????????????? break;
????????????????????????? case 4 :
????????????????????????????? iline = 1;
????????????????????????????? inc = 2;
????????????????????? }
????????????????? }
????????????????? line = iline;
????????????????? iline += inc;
????????????? }
????????????? line += iy;
????????????? if (line < height) {
????????????????? int k = line * width;
????????????????? int dx = k + ix; // start of line in dest
????????????????? int dlim = dx + iw; // end of dest line
????????????????? if ((k + width) < dlim) {
????????????????????? dlim = k + width; // past dest edge
????????????????? }
????????????????? int sx = i * iw; // start of line in source
????????????????? while (dx < dlim) {
????????????????????? // map color and insert in destination
????????????????????? int index = ((int) pixels[sx++]) & 0xff;
????????????????????? int c = act[index];
????????????????????? if (c != 0) {
????????????????????????? dest[dx] = c;
????????????????????? }
????????????????????? dx++;
????????????????? }
????????????? }
????????? }
????? }
??
????? /**
?????? * Gets the image contents of frame n.
?????? *
?????? * @return BufferedImage representation of frame, or null if n is invalid.
?????? */
????? public BufferedImage getFrame(int n) {
????????? BufferedImage im = null;
???????? if ((n >= 0) && (n < frameCount)) {
????????????? im = ((GifFrame) frames.get(n)).image;
????????? }
????????? return im;
????? }
??
????? /**
?????? * Gets image size.
?????? *
?????? * @return GIF image dimensions
????? */
????? public Dimension getFrameSize() {
????????? return new Dimension(width, height);
????? }
??
????? /**
?????? * Reads GIF image from stream
?????? *
?????? * @param BufferedInputStream containing GIF file.
?????? * @return read status code (0 = no errors)
?????? */
????? public int read(BufferedInputStream is) {
????????? init();
????????? if (is != null) {
????????????? in = is;
????????????? readHeader();
????????????? if (!err()) {
????????????????? readContents();
????????????????? if (frameCount < 0) {
????????????????????? status = STATUS_FORMAT_ERROR;
????????????????? }
????????????? }
????????? } else {
????????????? status = STATUS_OPEN_ERROR;
????????? }
????????? try {
????????????? is.close();
????????? } catch (IOException e) {
???????? }
????????? return status;
????? }
??
????? /**
?????? * Reads GIF image from stream
?????? *
?????? * @param InputStream containing GIF file.
?????? * @return read status code (0 = no errors)
?????? */
????? public int read(InputStream is) {
????????? init();
????????? if (is != null) {
????????????? if (!(is instanceof BufferedInputStream))
????????????????? is = new BufferedInputStream(is);
????????????? in = (BufferedInputStream) is;
????????????? readHeader();
????????????? if (!err()) {
????????????????? readContents();
????????????????? if (frameCount < 0) {
????????????????????? status = STATUS_FORMAT_ERROR;
????????????????? }
????????????? }
????????? } else {
????????????? status = STATUS_OPEN_ERROR;
????????? }
????????? try {
????????????? is.close();
????????? } catch (IOException e) {
????????? }
????????? return status;
????? }
??
????? /**
?????? * Reads GIF file from specified file/URL source??
?????? * (URL assumed if name contains ":/" or "file:")
?????? *
?????? * @param name String containing source
?????? * @return read status code (0 = no errors)
?????? */
????? public int read(String name) {
????????? status = STATUS_OK;
????????? try {
????????????? name = name.trim().toLowerCase();
????????????? if ((name.indexOf("file:") >= 0) ||
????????????????? (name.indexOf(":/") > 0)) {
????????????????? URL url = new URL(name);
????????????????? in = new BufferedInputStream(url.openStream());
????????????? } else {
???????????????? in = new BufferedInputStream(new FileInputStream(name));
????????????? }
????????????? status = read(in);
???????? } catch (IOException e) {
????????????? status = STATUS_OPEN_ERROR;
????????? }
??
????????? return status;
????? }
??
????? /**
?????? * Decodes LZW image data into pixel array.
?????? * Adapted from John Cristy's ImageMagick.
?????? */
????? protected void decodeImageData() {
????????? int NullCode = -1;
????????? int npix = iw * ih;
????????? int available,?
????????????? clear,
????????????? code_mask,
????????????? code_size,
????????????? end_of_information,
????????????? in_code,
????????????? old_code,
????????????? bits,
????????????? code,
????????????? count,
????????????? i,
????????????? datum,
????????????? data_size,
????????????? first,
????????????? top,
????????????? bi,
????????????? pi;
??
????????? if ((pixels == null) || (pixels.length < npix)) {
????????????? pixels = new byte[npix]; // allocate new pixel array
????????? }
???????? if (prefix == null) prefix = new short[MaxStackSize];
????????? if (suffix == null) suffix = new byte[MaxStackSize];
????????? if (pixelStack == null) pixelStack = new byte[MaxStackSize + 1];
??
????????? //? Initialize GIF data stream decoder.
??
????????? data_size = read();
????????? clear = 1 << data_size;
????????? end_of_information = clear + 1;
???????? available = clear + 2;
????????? old_code = NullCode;
????????? code_size = data_size + 1;
????????? code_mask = (1 << code_size) - 1;
????????? for (code = 0; code < clear; code++) {
????????????? prefix[code] = 0;
????????????? suffix[code] = (byte) code;
????????? }
??
????????? //? Decode GIF pixel stream.
??
????????? datum = bits = count = first = top = pi = bi = 0;
??
????????? for (i = 0; i < npix;) {
????????????? if (top == 0) {
????????????????? if (bits < code_size) {
????????????????????? //? Load bytes until there are enough bits for a code.
????????????????????? if (count == 0) {
????????????????????????? // Read a new data block.
????????????????????????? count = readBlock();
????????????????????????? if (count <= 0)
????????????????????????????? break;
???????????????????????? bi = 0;
????????????????????? }
????????????????????? datum += (((int) block[bi]) & 0xff) << bits;
????????????????????? bits += 8;
????????????????????? bi++;
????????????????????? count--;
????????????????????? continue;
????????????????? }
??
????????????????? //? Get the next code.
??
????????????????? code = datum & code_mask;
????????????????? datum >>= code_size;
????????????????? bits -= code_size;
??
????????????????? //? Interpret the code
??
????????????????? if ((code > available) || (code == end_of_information))
????????????????????? break;
????????????????? if (code == clear) {
????????????????????? //? Reset decoder.
????????????????????? code_size = data_size + 1;
????????????????????? code_mask = (1 << code_size) - 1;
????????????????????? available = clear + 2;
????????????????????? old_code = NullCode;
????????????????????? continue;
????????????????? }
????????????????? if (old_code == NullCode) {
????????????????????? pixelStack[top++] = suffix[code];
????????????????????? old_code = code;
????????????????????? first = code;
????????????????????? continue;
????????????????? }
????????????????? in_code = code;
????????????????? if (code == available) {
????????????????????? pixelStack[top++] = (byte) first;
????????????????????? code = old_code;
????????????????? }
????????????????? while (code > clear) {
????????????????????? pixelStack[top++] = suffix[code];
????????????????????? code = prefix[code];
????????????????? }
????????????????? first = ((int) suffix[code]) & 0xff;
??
????????????????? //? Add a new string to the string table,
??
????????????????? if (available >= MaxStackSize)
????????????????????? break;
????????????????? pixelStack[top++] = (byte) first;
????????????????? prefix[available] = (short) old_code;
????????????????? suffix[available] = (byte) first;
????????????????? available++;
????????????????? if (((available & code_mask) == 0)
????????????????????? && (available < MaxStackSize)) {
???????????????????? code_size++;
????????????????????? code_mask += available;
????????????????? }
????????????????? old_code = in_code;
????????????? }
??
????????????? //? Pop a pixel off the pixel stack.
??
????????????? top--;
????????????? pixels[pi++] = pixelStack[top];
????????????? i++;
????????? }
??
????????? for (i = pi; i < npix; i++) {
???????????? pixels[i] = 0; // clear missing pixels
????????? }
??
????? }
??
????? /**
?????? * Returns true if an error was encountered during reading/decoding
?????? */
????? protected boolean err() {
????????? return status != STATUS_OK;
????? }
??
????? /**
?????? * Initializes or re-initializes reader
?????? */
????? protected void init() {
????????? status = STATUS_OK;
????????? frameCount = 0;
???????? frames = new ArrayList();
????????? gct = null;
????????? lct = null;
????? }
??
????? /**
?????? * Reads a single byte from the input stream.
?????? */
????? protected int read() {
????????? int curByte = 0;
????????? try {
????????????? curByte = in.read();
????????? } catch (IOException e) {
????????????? status = STATUS_FORMAT_ERROR;
????????? }
????????? return curByte;
????? }
??
????? /**
?????? * Reads next variable length block from input.
?????? *
?????? * @return number of bytes stored in "buffer"
?????? */
????? protected int readBlock() {
????????? blockSize = read();
????????? int n = 0;
????????? if (blockSize > 0) {
????????????? try {
????????????????? int count = 0;
????????????????? while (n < blockSize) {
????????????????????? count = in.read(block, n, blockSize - n);
????????????????????? if (count == -1)?
????????????????????????? break;
????????????????????? n += count;
????????????????? }
????????????? } catch (IOException e) {
????????????? }
??
????????????? if (n < blockSize) {
???????????????? status = STATUS_FORMAT_ERROR;
????????????? }
????????? }
????????? return n;
????? }
??
????? /**
?????? * Reads color table as 256 RGB integer values
?????? *
?????? * @param ncolors int number of colors to read
?????? * @return int array containing 256 colors (packed ARGB with full alpha)
?????? */
????? protected int[] readColorTable(int ncolors) {
????????? int nbytes = 3 * ncolors;
????????? int[] tab = null;
????????? byte[] c = new byte[nbytes];
????????? int n = 0;
????????? try {
????????????? n = in.read(c);
????????? } catch (IOException e) {
????????? }
????????? if (n < nbytes) {
????????????? status = STATUS_FORMAT_ERROR;
????????? } else {
????????????? tab = new int[256]; // max size to avoid bounds checks
????????????? int i = 0;
????????????? int j = 0;
????????????? while (i < ncolors) {
????????????????? int r = ((int) c[j++]) & 0xff;
????????????????? int g = ((int) c[j++]) & 0xff;
????????????????? int b = ((int) c[j++]) & 0xff;
????????????????? tab[i++] = 0xff000000 | (r << 16) | (g << 8) | b;
????????????? }
????????? }
????????? return tab;
????? }
??
????? /**
?????? * Main file parser.? Reads GIF content blocks.
?????? */
????? protected void readContents() {
????????? // read GIF file content blocks
????????? boolean done = false;
????????? while (!(done || err())) {
????????????? int code = read();
????????????? switch (code) {
??
????????????????? case 0x2C : // image separator
????????????????????? readImage();
????????????????????? break;
??
????????????????? case 0x21 : // extension
????????????????????? code = read();
????????????????????? switch (code) {
????????????????????????? case 0xf9 : // graphics control extension
????????????????????????????? readGraphicControlExt();
????????????????????????????? break;
??
????????????????????????? case 0xff : // application extension
????????????????????????????? readBlock();
????????????????????????????? String app = "";
????????????????????????????? for (int i = 0; i < 11; i++) {
????????????????????????????????? app += (char) block[i];
????????????????????????????? }
????????????????????????????? if (app.equals("NETSCAPE2.0")) {
????????????????????????????????? readNetscapeExt();
????????????????????????????? }
????????????????????????????? else
????????????????????????????????? skip(); // don't care
????????????????????????????? break;
??
????????????????????????? default : // uninteresting extension
????????????????????????????? skip();
????????????????????? }
????????????????????? break;
??
????????????????? case 0x3b : // terminator
????????????????????? done = true;
????????????????????? break;
??
????????????????? case 0x00 : // bad byte, but keep going and see what happens
????????????????????? break;
??
????????????????? default :
????????????????????? status = STATUS_FORMAT_ERROR;
????????????? }
???????? }
????? }
??
????? /**
?????? * Reads Graphics Control Extension values
????? */
???? protected void readGraphicControlExt() {
???????? read(); // block size
????????? int packed = read(); // packed fields
????????? dispose = (packed & 0x1c) >> 2; // disposal method
????????? if (dispose == 0) {
????????????? dispose = 1; // elect to keep old image if discretionary
????????? }
????????? transparency = (packed & 1) != 0;
????????? delay = readShort() * 10; // delay in milliseconds
????????? transIndex = read(); // transparent color index
????????? read(); // block terminator
????? }
??
????? /**
?????? * Reads GIF file header information.
?????? */
????? protected void readHeader() {
????????? String id = "";
????????? for (int i = 0; i < 6; i++) {
????????????? id += (char) read();
????????? }
????????? if (!id.startsWith("GIF")) {
????????????? status = STATUS_FORMAT_ERROR;
????????????? return;
????????? }
??
????????? readLSD();
????????? if (gctFlag && !err()) {
????????????? gct = readColorTable(gctSize);
????????????? bgColor = gct[bgIndex];
????????? }
????? }
??
????? /**
?????? * Reads next frame image
????? */
????? protected void readImage() {
????????? ix = readShort(); // (sub)image position & size
????????? iy = readShort();
????????? iw = readShort();
????????? ih = readShort();
??
????????? int packed = read();
????????? lctFlag = (packed & 0x80) != 0; // 1 - local color table flag
????????? interlace = (packed & 0x40) != 0; // 2 - interlace flag
????????? // 3 - sort flag
????????? // 4-5 - reserved
????????? lctSize = 2 << (packed & 7); // 6-8 - local color table size
??
????????? if (lctFlag) {
????????????? lct = readColorTable(lctSize); // read table
????????????? act = lct; // make local table active
????????? } else {
????????????? act = gct; // make global table active
????????????? if (bgIndex == transIndex)
????????????????? bgColor = 0;
????????? }
????????? int save = 0;
????????? if (transparency) {
????????????? save = act[transIndex];
????????????? act[transIndex] = 0; // set transparent color if specified
????????? }
??
????????? if (act == null) {
????????????? status = STATUS_FORMAT_ERROR; // no color table defined
????????? }
??
????????? if (err()) return;
??
????????? decodeImageData(); // decode pixel data
????????? skip();
??
????????? if (err()) return;
??
????????? frameCount++;
??
????????? // create new image to receive frame data
????????? image =
????????????? new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB_PRE);
??
????????? setPixels(); // transfer pixel data to image
??
????????? frames.add(new GifFrame(image, delay)); // add image to frame list
??
????????? if (transparency) {
????????????? act[transIndex] = save;
????????? }
????????? resetFrame();
??
????? }
??
????? /**
?????? * Reads Logical Screen Descriptor
?????? */
????? protected void readLSD() {
??
????????? // logical screen size
???????? width = readShort();
???????? height = readShort();
??
????????? // packed fields
????????? int packed = read();
????????? gctFlag = (packed & 0x80) != 0; // 1?? : global color table flag
????????? // 2-4 : color resolution
????????? // 5?? : gct sort flag
????????? gctSize = 2 << (packed & 7); // 6-8 : gct size
??
????????? bgIndex = read(); // background color index
????????? pixelAspect = read(); // pixel aspect ratio
????? }
??
????? /**
?????? * Reads Netscape extenstion to obtain iteration count
?????? */
????? protected void readNetscapeExt() {
????????? do {
????????????? readBlock();
????????????? if (block[0] == 1) {
????????????????? // loop count sub-block
????????????????? int b1 = ((int) block[1]) & 0xff;
????????????????? int b2 = ((int) block[2]) & 0xff;
????????????????? loopCount = (b2 << 8) | b1;
????????????? }
????????? } while ((blockSize > 0) && !err());
????? }
??
????? /**
?????? * Reads next 16-bit value, LSB first
?????? */
????? protected int readShort() {
????????? // read 16-bit value, LSB first
????????? return read() | (read() << 8);
????? }
??
????? /**
?????? * Resets frame state for reading next image.
?????? */
????? protected void resetFrame() {
????????? lastDispose = dispose;
????????? lastRect = new Rectangle(ix, iy, iw, ih);
????????? lastImage = image;
????????? lastBgColor = bgColor;
????????? int dispose = 0;
????????? boolean transparency = false;
????????? int delay = 0;
????????? lct = null;
????? }
??
????? /**
?????? * Skips variable length blocks up to and including
?????? * next zero length block.
?????? */
????? protected void skip() {
????????? do {
????????????? readBlock();
????????? } while ((blockSize > 0) && !err());
????? }
? }

//LZWEncoder.java

??? package ip.gif.neuquantAnimation;
????
??? import java.io.OutputStream;
??? import java.io.IOException;
????
??? //==============================================================================
??? //? Adapted from Jef Poskanzer's Java port by way of J. M. G. Elliott.
??? //? K Weiner 12/00
????
?? 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 (mgardi@watdcsu.waterloo.edu)
???
?????? // 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);
????????? }
????? }
? }


//NeuQuant.java

??? package ip.gif.neuquantAnimation;
????
??? /* NeuQuant Neural-Net Quantization Algorithm
???? * ------------------------------------------
???? *
???? * Copyright (c) 1994 Anthony Dekker
???? *
???? * NEUQUANT Neural-Net quantization algorithm by Anthony Dekker, 1994.
???? * See "Kohonen neural networks for optimal colour quantization"
??? * in "Network: Computation in Neural Systems" Vol. 5 (1994) pp 351-367.
??? * for a discussion of the algorithm.
??? *
??? * Any party obtaining a copy of these files from the author, directly or
??? * indirectly, is granted, free of charge, a full and unrestricted irrevocable,
??? * world-wide, paid up, royalty-free, nonexclusive right and license to deal
??? * in this software and documentation files (the "Software"), including without
??? * limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
??? * and/or sell copies of the Software, and to permit persons who receive
??? * copies from any such party to do so, with the only requirement being
??? * that this copyright notice remain intact.
??? */
???
?? // Ported to Java 12/00 K Weiner
???
?? 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);
????? }
? }