PHP实现GIF图片验证码

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这是一个用PHP生成GIF动画来实现动态图片验证码的程序,非常实用,是PHP用户注册登录界面经常需要用到的验证码程序,有需要GIF动态图片验证码功能的朋友可以收藏一下。

第一步:创建ImageCode.PHP文件,验证码生成函数代码如下:

PHP;"> PHP /** * 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); // 设定文字颜色数组 $colorList[] = ImageColorAllocate($image,15,73,210); $colorList[] = ImageColorAllocate($image,64,0); $colorList[] = ImageColorAllocate($image,64); $colorList[] = ImageColorAllocate($image,128,128); $colorList[] = ImageColorAllocate($image,27,52,47); $colorList[] = ImageColorAllocate($image,51,102); $colorList[] = ImageColorAllocate($image,145); $colorList[] = ImageColorAllocate($image,113); $colorList[] = ImageColorAllocate($image,51); $colorList[] = ImageColorAllocate($image,158,180,35); $colorList[] = ImageColorAllocate($image,59,59); $colorList[] = ImageColorAllocate($image,1,180); $colorList[] = ImageColorAllocate($image,153,60,131,1); $colorList[] = ImageColorAllocate($image,0); $fontcolor = ImageColorAllocate($image,0); $gray = ImageColorAllocate($image,245,245); $color = imagecolorallocate($image,255,255); $color2 = imagecolorallocate($image,0); imagefill($image,$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[$colorRandom]);  
}
// <a href="https://www.jb51.cc/tag/tianjia/" target="_blank" class="keywords">添加</a>干扰线
for($k = 0; $k < 3; $k++)
{
  $colorRandom = mt_rand(0,sizeof($colorList)-1);
  // $todrawline = rand(0,1);
  $todrawline = 1;
  if($todrawline)
  {
    imageline($image,mt_rand(0,$board_width),$board_height),$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 )!",$this->ERR [ 'ERR02' ],$GIF_mod);

     exit(0); 

    }
    if (substr($this->BUF[$i],6) != "GIF87a" && substr($this->BUF [$i],6) != "GIF89a")

    {

     printf( "%s: %d %s",$i,$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->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 ],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],3
    (2 << ( ord ( $this->BUF[0]{10} ) & 0x07)));
    $Locals_rgb = substr ( $this->BUF[$i],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,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);
}
}

第二步:验证码生成,创建yzimg.PHP,并引用入文件ImageCode.PHP代码如下:

PHP;"> PHP if(!isset($_SESSION)){ session_start(); } require_once(dirname(__FILE__)."ImageCode.PHP"); unset($_SESSION['yzm']); $randCode = ''; $chars = 'abcdefghjkmnpqrstuvwxyzABCDEFGHJKLMNPRSTUVWXYZ23456789'; for ( $i = 0; $i < 4; $i++ ) { $randCode .= substr($chars,strlen($chars) - 1),1); } $_SESSION['yzm']=$randCode; // 记录session ImageCode($randCode,60);

/方法二/
/$authstr = mt_rand(1000,9999); // 生成随机字符串
$_SESSION['yzm'] = $authstr; // 记录session
ImageCode($authstr,60); // 显示GIF动画
/
?>

第三步:调用显示验证码,在需要添加验证码的页面加入以下代码代码如下:

PHP;">

以上就是为大家分享的如何使用PHP生成动态验证码的相应代码,希望对大家的学习有所帮助。

原文链接:https://www.f2er.com/php/21001.html

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