import ij.plugin.*;
import ij.*;
import ij.process.*;
import ij.io.*;
import java.net.*;
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.image.*;
public class Animated_Gif_Reader implements PlugIn {
public void run(String arg) {
OpenDialog od = new OpenDialog("Animated Gif Reader", null);
String name = od.getFileName();
if (name==null)
return;
String dir = od.getDirectory();
GifDecoder d = new GifDecoder();
int status = d.read(dir+name);
int n = d.getFrameCount();
ImageStack stack = null;
for (int i=0; i < n; i++) {
ImageProcessor frame = d.getFrame(i);
if (i==0)
stack = new ImageStack(frame.getWidth(), frame.getHeight());
int t = d.getDelay(i); // display duration of frame in milliseconds
stack.addSlice(null, frame);
}
if (stack!=null) new ImagePlus(name, stack).show();
}
}
/**
* Class GifDecoder - Decodes a GIF file into one or more frames.
*
* Example: * GifDecoder d = new GifDecoder(); * d.read("sample.gif"); * int n = d.getFrameCount(); * for (int i = 0; i < n; i++) { * ImageProcessor frame = d.getFrame(i); // frame i * int t = d.getDelay(i); // display duration of frame in milliseconds * // do something with frame * } ** No copyright asserted on this code assembly. 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 1.0 January 2001 * * June 2001: Updated to work with ImageJ and JDK 1.1 */ 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; // 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 ImageProcessor image; // current frame protected ImageProcessor 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 Vector frames; // frames read from current file protected int frameCount; /** * 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.elementAt(n)).delay; return delay; } /** * Gets the image contents of frame n. * * @return ImageProcessor representation of frame, or null if n is invalid. */ public ImageProcessor getFrame(int n) { ImageProcessor im = null; if ((n >= 0) && (n < frameCount)) im = ((GifFrame) frames.elementAt(n)).image; return im; } /** * Gets the number of frames read from file. * @return int frame count */ public int getFrameCount() { return frameCount; } /** * Gets the first (or only) image read. * * @return ImageProcessor containing first frame, or null if none. */ public ImageProcessor getImage() { return getFrame(0); } /** * Gets the "Netscape" iteration count, if any. * A count of 0 means repeat indefinitiely. * * @return int iteration count if one was specified, else 1. */ public int getLoopCount() { return loopCount; } /** * Reads GIF image from stream * * @param BufferedInputStream containing GIF file. * @return int read status code */ 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 file from specified source (file or URL string) * * @param name File source string * @return int read status code */ public int read(String name) { status = STATUS_OK; try { name = name.trim(); if (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 Vector(); 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 int number of bytes stored in "buffer" */ protected int readBlock() { blockSize = read(); int n = 0; int count; if (blockSize > 0) { try { while (n