<?php/** * 调用示例 * */session_start();$randCode = ‘‘;//验证码随机$str="abcdefghjkmnpqrstuvwsyzABCDEFGHJKMNPQRSTUVWSYZ23456789";for($i=0;$i<4;$i++){    $safe.=substr($str,rand(0,strlen($str)),1);}$_SESSION["imgcode"]=$safe;ImageCode($safe, 60);                // 显示GIF动画/** * ImageCode 生成GIF图片验证 * @param $string 字符串 * @param $width 宽度 * @param $height 高度 * */function ImageCode($string = ‘‘, $width = 75, $height = 25){    $authstr = $string ? $string : ((time() % 2 == 0) ? mt_rand(1000, 9999) : mt_rand(10000, 99999));     $board_width = $width;    $board_height = $height;    // 生成一个32帧的GIF动画    for($i = 0; $i < 32; $i++){        ob_start();        $image = imagecreate($board_width, $board_height);        imagecolorallocate($image, 0,0,0);        // 设定文字颜色数组          $colorList[] = ImageColorAllocate($image, 15,73,210);         $colorList[] = ImageColorAllocate($image, 0,64,0);         $colorList[] = ImageColorAllocate($image, 0,0,64);         $colorList[] = ImageColorAllocate($image, 0,128,128);         $colorList[] = ImageColorAllocate($image, 27,52,47);         $colorList[] = ImageColorAllocate($image, 51,0,102);         $colorList[] = ImageColorAllocate($image, 0,0,145);         $colorList[] = ImageColorAllocate($image, 0,0,113);         $colorList[] = ImageColorAllocate($image, 0,51,51);         $colorList[] = ImageColorAllocate($image, 158,180,35);         $colorList[] = ImageColorAllocate($image, 59,59,59);         $colorList[] = ImageColorAllocate($image, 0,0,0);         $colorList[] = ImageColorAllocate($image, 1,128,180);         $colorList[] = ImageColorAllocate($image, 0,153,51);         $colorList[] = ImageColorAllocate($image, 60,131,1);         $colorList[] = ImageColorAllocate($image, 0,0,0);         $fontcolor = ImageColorAllocate($image, 0,0,0);         $gray = ImageColorAllocate($image, 245,245,245);         $color = imagecolorallocate($image, 255,255,255);        $color2 = imagecolorallocate($image, 255,0,0);        imagefill($image, 0, 0, $gray);        $space = 15;// 字符间距        if($i > 0){    // 屏蔽第一帧            for ($k = 0; $k < strlen($authstr); $k++) {                 $colorRandom = mt_rand(0,sizeof($colorList)-1);                 $float_top = rand(0,4);                $float_left = rand(0,3);                imagestring($image, 6, $space * $k, $top + $float_top, substr($authstr, $k, 1), $colorList[$colorRandom]);            }        }        for ($k = 0; $k < 20; $k++) {             $colorRandom = mt_rand(0,sizeof($colorList)-1);              imagesetpixel($image, rand()%70 , rand()%15 , $colorList[$colorRandom]);             }        // 添加干扰线        for($k = 0; $k < 5; $k++){            $colorRandom = mt_rand(0, sizeof($colorList)-1);             // $todrawline = rand(0,1);            $todrawline = 1;            if($todrawline){                imageline($image, mt_rand(0, $board_width), mt_rand(0,$board_height), mt_rand(0,$board_width), mt_rand(0,$board_height), $colorList[$colorRandom]);            }else{                $w = mt_rand(0,$board_width);                $h = mt_rand(0,$board_width);                imagearc($image, $board_width - floor($w / 2) , floor($h / 2), $w, $h,  rand(90,180), rand(180,270), $colorList[$colorRandom]);            }        }        imagegif($image);        imagedestroy($image);        $imagedata[] = ob_get_contents();        ob_clean();          ++$i;      }    $gif = new GIFEncoder($imagedata);      Header (‘Content-type:image/gif‘);      echo $gif->GetAnimation();  }/** * GIFEncoder类 * */class GIFEncoder {    var $GIF = "GIF89a";                /* GIF header 6 bytes        */      var $VER = "GIFEncoder V2.06";        /* Encoder version             */      var $BUF = Array ( );      var $LOP =  0;      var $DIS =  2;      var $COL = -1;      var $IMG = -1;      var $ERR = Array (          ‘ERR00‘ =>"Does not supported function for only one image!",          ‘ERR01‘ =>"Source is not a GIF image!",          ‘ERR02‘ =>"Unintelligible flag ",          ‘ERR03‘ =>"Could not make animation from animated GIF source",      );      function GIFEncoder ($GIF_src, $GIF_dly = 100, $GIF_lop = 0, $GIF_dis = 0,  $GIF_red = 0, $GIF_grn = 0, $GIF_blu = 0, $GIF_mod = ‘bin‘ ) {          if (!is_array($GIF_src) && !is_array($GIF_tim)) {              printf ( "%s: %s", $this->VER, $this->ERR[‘ERR00‘]);              exit( 0 );        }          $this->LOP = ($GIF_lop > -1) ? $GIF_lop : 0;          $this->DIS = ($GIF_dis > -1) ? (( $GIF_dis < 3 ) ? $GIF_dis : 3) : 2;          $this->COL = ($GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1) ? ($GIF_red | ($GIF_grn << 8) | ($GIF_blu << 16)) : -1;          for ($i = 0, $src_count = count($GIF_src); $i < $src_count; $i++ ) {            if (strToLower( $GIF_mod ) == "url") {                  $this->BUF[] = fread (fopen($GIF_src [$i], "rb"), filesize ($GIF_src [$i]));              }elseif(strToLower($GIF_mod) == "bin") {                  $this->BUF [ ] = $GIF_src [ $i ];              }else{                  printf("%s: %s ( %s )!", $this->VER, $this->ERR [ ‘ERR02‘ ], $GIF_mod);                  exit(0);              }              if (substr($this->BUF[$i], 0, 6) != "GIF87a" && substr($this->BUF [$i], 0, 6) != "GIF89a") {                  printf( "%s: %d %s", $this->VER, $i, $this->ERR [‘ERR01‘]);                  exit(0);              }              for ($j = (13 + 3 * (2 << (ord($this->BUF[$i]{10}) & 0x07 ))), $k = TRUE; $k; $j++){                  switch ($this->BUF [$i]{$j}) {                      case "!":                          if ((substr($this->BUF[$i], ($j + 3), 8)) == "NETSCAPE") {                                  printf( "%s: %s ( %s source )!", $this->VER, $this->ERR [‘ERR03‘], ($i + 1));                                  exit( 0 );                          }                          break;                      case ";":                          $k = FALSE;                          break;                  }              }          }          GIFEncoder::GIFAddHeader();          for($i = 0, $count_buf = count($this->BUF); $i < $count_buf; $i++) {              GIFEncoder::GIFAddFrames($i, $GIF_dly[$i]);          }          GIFEncoder::GIFAddFooter();      }          function GIFAddHeader ( ) {          $cmap = 0;          if (ord($this->BUF[0]{10}) & 0x80 ) {              $cmap = 3 * ( 2 << ( ord ( $this->BUF [ 0 ]{10} ) & 0x07 ));                          $this->GIF .= substr ( $this->BUF [ 0 ], 6, 7);              $this->GIF .= substr ( $this->BUF [ 0 ], 13, $cmap);              $this->GIF .= "!\377\13NETSCAPE2.0\3\1" . GIFEncoder::GIFWord ( $this->LOP ) . "\0";          }      }          function GIFAddFrames ( $i, $d ) {          $Locals_str = 13 + 3 * (2 <<(ord($this->BUF[$i]{10}) & 0x07));          $Locals_end = strlen($this->BUF[$i]) - $Locals_str - 1;          $Locals_tmp = substr ($this->BUF[$i], $Locals_str, $Locals_end);          $Global_len = 2 << (ord( $this->BUF [0]{10} ) & 0x07 );          $Locals_len = 2 << (ord( $this->BUF[$i]{10}) & 0x07);          $Global_rgb = substr($this->BUF[0], 13, 3 * (2 << ( ord ( $this->BUF[0]{10} ) & 0x07)));          $Locals_rgb = substr ( $this->BUF[$i], 13, 3 * (2 << ( ord ( $this->BUF[$i]{10} ) & 0x07)));          $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 0) . chr(($d >> 0) & 0xFF) . chr(($d >> 8) & 0xFF) . "\x0\x0";          if ( $this->COL > -1 && ord($this->BUF[$i]{10}) & 0x80){              for($j = 0; $j < (2 << (ord( $this->BUF[$i]{10}) & 0x07)); $j++ ) {                  if(ord ($Locals_rgb{3 * $j + 0}) == ($this->COL >>  0) & 0xFF && ord ( $Locals_rgb { 3 * $j + 1 } ) == ( $this->COL >>  8 ) & 0xFF && ord ( $Locals_rgb { 3 * $j + 2 } ) == ( $this->COL >> 16 ) & 0xFF ) {                      $Locals_ext = "!\xF9\x04" . chr(($this->DIS << 2) + 1) . chr (( $d >> 0) & 0xFF) . chr (( $d >> 8) & 0xFF) . chr ($j) . "\x0";                      break;                  }              }          }          switch ( $Locals_tmp { 0 } ) {              case "!":                  $Locals_img = substr($Locals_tmp, 8, 10);                  $Locals_tmp = substr($Locals_tmp, 18, strlen ($Locals_tmp) - 18);                  break;              case ",":                  $Locals_img = substr($Locals_tmp, 0, 10);                  $Locals_tmp = substr($Locals_tmp, 10, strlen($Locals_tmp) - 10);                  break;          }          if ( ord ( $this->BUF[$i]{10} ) & 0x80 && $this->IMG > -1 ) {              if ( $Global_len == $Locals_len ) {                  if ( GIFEncoder::GIFBlockCompare ( $Global_rgb, $Locals_rgb, $Global_len ) ) {                      $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );                  }else{                      $byte  = ord ( $Locals_img{9});                      $byte |= 0x80;                      $byte &= 0xF8;                      $byte |= ( ord ( $this->BUF [ 0 ]{10}) & 0x07);                      $Locals_img{9} = chr($byte);                      $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);                  }              }else{                  $byte  = ord($Locals_img{9});                  $byte |= 0x80;                  $byte &= 0xF8;                  $byte |= (ord($this->BUF[$i]{10}) & 0x07);                  $Locals_img {9} = chr($byte);                  $this->GIF .= ($Locals_ext . $Locals_img . $Locals_rgb . $Locals_tmp);              }          }else{              $this->GIF .= ( $Locals_ext . $Locals_img . $Locals_tmp );          }          $this->IMG  = 1;      }          function GIFAddFooter ( ) {          $this->GIF .= ";";      }          function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len ) {          for ( $i = 0; $i < $Len; $i++ ) {              if($GlobalBlock { 3 * $i + 0 } != $LocalBlock { 3 * $i + 0 } || $GlobalBlock { 3 * $i + 1 } != $LocalBlock { 3 * $i + 1 } || $GlobalBlock { 3 * $i + 2 } != $LocalBlock{3 * $i + 2}) {                  return ( 0 );              }          }          return ( 1 );      }          function GIFWord ( $int ) {         return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) );      }          function GetAnimation ( ) {          return ($this->GIF);      }  }