终于搞定多张JPG图片转成GIF动画这个难题,解决方法如下。

   这几天,一直在搞这个问题,就是想把自己所得到的多张的JPG图片文件,转成一张GIF的动画,然后让它来执行。

     刚开始的时候,也摸索了很久,这个问题,看到网上面的也有很多的方法,但是都是不能够使用,很是郁闷。其实网上的方法,也是能够用的,但是有它的局限性,一般来说,都是用的是LZW的一种GIF算法来实现这个过程,作为一名软件人员,所要做的事是使用轮子,所以,可以直接使用别人写好的算法,然后根据自己的需求来实现一些相应的功能,GIF也是如此。

   刚才提到了网上的一些方法,它的局限性在于,只是适用于JAVA,而不是android上,而我们的目标正是实现在andorid上,到底有什么不一样的地方呢,下面我详细说一下。

  根据我几天以来的发现,第一种方案, android里面,也可以实现一些纯java 的程度,只是会有一些限制,例如有很多纯java 的库包在android中,并不存在,所以这个方法实现起来并不容易,故弃之。

    说到这里,还是要提到网上一些适用于JAVA的方法,为什么在android里面,就不能用了呢,这是因为,在这些代码里面,使用了一些java.awt.*里面的库,以及一个ImageIO的库包,所以不能在android里面实现,我也想过,把这些库包提出来放到android工程下面去使用,结果失败,老是报 Conversion to Dalvik format failed with error 1错误,查了网上各种各样的方法,都没有生效,郁闷之。如果各网友想要查,可以在jdk的lib下面找到一个rt.jar的库包,里面就有这些所需要调用到的库文件。所以这种方法,也被我放弃。

  最后,我还是想,到底怎么才可以实现这个功能,我后来想到对这些java文件,进行一些改造,用一些android里面的类来替代awt和ImageIO库,这样应该可以吧,

在自己的不断努力之下,终于实现了这一功能,说起来实现的非常巧,并不是说我功力有多深,只是随例试了一下,给我试出来了,个人也是感觉自己运气比较好,呵呵。

  下面就不说废话了,直接帖代码:

     

public class jpgToGif {

 
 //synchronized
   public  static void jpgToGif(String pic[],  
             String newPic) {  
         try {  
           Log.i("jpgToGif","is connection ="+newPic);
             AnimatedGifEncoder1 e = new AnimatedGifEncoder1();   
             e.setRepeat(1);  
             e.start(newPic);  
            
             for (int i = 0; i < pic.length; i++) {  
                 e.setDelay(200); // 设置播放的延迟时间  
                Bitmap src=BitmapFactory.decodeFile(pic[i]);
                 e.addFrame(src); // 添加到帧中  
             }  
             e.finish();//刷新任何未决的数据,并关闭输出文件  
         } catch (Exception e) {  
             e.printStackTrace();  
         }  
     } 
 }

AnimatedGifEncoder1.java


public class AnimatedGifEncoder1
{
  protected boolean closeStream;
  protected int colorDepth;
  protected byte[] colorTab;
  protected int delay = 0;
  protected int dispose;
  protected boolean firstFrame;
  protected int height;
  protected Bitmap image;
  protected byte[] indexedPixels;
  protected OutputStream out;
  protected int palSize;
  protected byte[] pixels;
  protected int repeat = -1;
  protected int sample;
  protected boolean sizeSet;
  protected boolean started ;
  protected int transIndex;
  protected int transparent = 0;
  protected boolean[] usedEntry;
  protected int width;

  public AnimatedGifEncoder1()
  {
    boolean[] arrayOfBoolean = new boolean[256];
    this.usedEntry = arrayOfBoolean;
    this.palSize = 7;
    this.dispose = -1;
    this.closeStream = false;
    this.firstFrame = true;
    this.sizeSet = false;
    this.sample = 10;
  }

  public boolean addFrame(Bitmap paramBitmap)
  {
    boolean ok = true;
    if(paramBitmap==null  || !started)
    {
     return false;
    }
 
      try
      {
       Log.i("AnimatedGifEncode...","AnimatedGifEncode is addFrame ="+paramBitmap);
        if (!sizeSet)
        {
          int i = paramBitmap.getWidth();
          int l = paramBitmap.getHeight();
          setSize(i, l);
        }
        this.image = paramBitmap;
        getImagePixels();
        analyzePixels();
      if(firstFrame)
        {
          writeLSD();
          writePalette();
          if(repeat>=0)
            writeNetscapeExt();
        }
        writeGraphicCtrlExt();
        writeImageDesc();
 
        if (!firstFrame)
          writePalette();
        writePixels();
        this.firstFrame = false;
    
      }
      catch (IOException localIOException1)
      {
       ok=false;
      
    
     
      }
      return ok;
   
  }

  protected void analyzePixels()
  {
    int len = this.pixels.length;
    int nPix = len / 3;
    byte[] arrayOfByte1 = new byte[nPix];
    this.indexedPixels = arrayOfByte1;
    byte[] arrayOfByte2 = this.pixels;
    int k = this.sample;
    NeuQuant nq = new NeuQuant(arrayOfByte2, len, k);
    this.colorTab = nq.process();
    int l = 0;
    int i1 = this.colorTab.length;
    Object localObject;
    if (l >= i1)
    {
      l = 0;
      localObject = null;
    }
 
        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;  
           }  
        int k1 = 0;  
           for (int i = 0; i < nPix; i++) {  
               int index =  
                   nq.map(pixels[k1++] & 0xff,  
                          pixels[k1++] & 0xff,  
                          pixels[k1++] & 0xff);  
               usedEntry[index] = true;  
               indexedPixels[i] = (byte) index;  
           }
           pixels = null;  
           colorDepth = 8;  
           palSize = 7;  
           if (transparent != 0) {  
               transIndex = findClosest(transparent);  
           }  
   
  }

  protected int findClosest(int paramInt)
  {
 
    if (colorTab == null)
    {
      return -1;
    }
    int r = Color.red(paramInt);
    int g = Color.green(paramInt);
    int b = Color.blue(paramInt);
    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;  
  }

 
 
  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;  
  }

  protected void getImagePixels()
  {
    int w = this.image.getWidth();
    int h = this.image.getHeight();
    Bitmap.Config localConfig = Bitmap.Config.ARGB_8888;
    Bitmap localBitmap1 = Bitmap.createBitmap(w, h, localConfig);
    Canvas localCanvas = new Canvas(localBitmap1);
    localCanvas.save();
    Paint localPaint = new Paint();
    localCanvas.drawBitmap(image, 0, 0, localPaint);
    localCanvas.restore();
  
    this.pixels =new byte[w * h * 3];
    int[] arrayOfInt = new int[w * h];
    int k = 0;
    int l = 0;
    int i1 = w;
    localBitmap1.getPixels(arrayOfInt, 0, w, k, l, i1, h);
    int localObject = 0;
    while (true)
    {
   
      if (localObject >= arrayOfInt.length)
        return;   
      pixels[localObject * 3] = (byte)Color.blue(arrayOfInt[localObject]);  
      pixels[localObject * 3+1] = (byte)Color.green(arrayOfInt[localObject]);
      pixels[localObject * 3+2] = (byte)Color.red(arrayOfInt[localObject]);
      ++localObject;
    }
  }

  public void setDelay(int ms) {  
      delay = Math.round(ms / 10.0f);  
  }  

 
 
  public void setDispose(int code) {  
      if (code >= 0) {  
          dispose = code;  
      }  
  }  
 
 

  public void setFrameRate(float fps) {  
      if (fps != 0f) {  
          delay = Math.round(100f / fps);  
      }  
  } 

  public void setQuality(int quality) {  
      if (quality < 1) quality = 1;  
      sample = quality;  
  }
 
 
  public void setRepeat(int iter) {  
      if (iter >= 0) {  
        Log.i("AnimatedGifEncode...","AnimatedGifEncode is setRepeat..setRepeat =");
          repeat = iter;  
      }  
  }  

  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;  
  }  
 
 

  public void setTransparent(int c)
  {
    this.transparent = c;
  }

  public boolean start(OutputStream os)
  {
    if (os == null) return false;  
       boolean ok = true;  
       closeStream = false;  
       out = os;  
       Log.i("AnimatedGifEncode...","AnimatedGifEncode is start outputSteam");
       try {  
           writeString("GIF89a"); // header  
       } catch (IOException e) {  
           ok = false;  
       }  
       return started = ok;  
  }

 
  public boolean start(String file) {  
      boolean ok = true;  
      try {  
          out = new BufferedOutputStream(new FileOutputStream(file));  
          ok = start(out);  
          Log.i("AnimatedGifEncode...","AnimatedGifEncode is start ="+file);
          closeStream = true;  
      } catch (IOException e) {  
          ok = false;  
      }  
      return started = ok;  
  }  

  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 == 0) {  
          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  
  }  

  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  
      }  
  }  
 
 

  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  
  }  

 
  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  
  }  

  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);  
      }  
  }  
 

  protected void writePixels() throws IOException {  
      LZWEncoder encoder =  
          new LZWEncoder(width, height, indexedPixels, colorDepth);  
      encoder.encode(out);  
  }  
    
  protected void writeShort(int value) throws IOException {  
      out.write(value & 0xff);  
      out.write((value >> 8) & 0xff);  
  }  
    

  protected void writeString(String s) throws IOException {  
      for (int i = 0; i < s.length(); i++) {  
          out.write((byte) s.charAt(i));
          Log.i("AnimatedGifEncode...","AnimatedGifEncode is read header!!!");
      }  
  } 
}

 

LZWEncoder.java


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);
  }
 }
}

 

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);
  }
 }

在调用的时候, jpgToGif.jpgToGif(pic, "/mnt/sdcard/1.gif"); 其中pic为一个string数组,具体内容是路径的名称,也就是多个JPEG文件的路径,1.gif为生成的gif文件,

如果有问题,可以在下面问,谢谢来看我的博客。。。。

 

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