Home > Article > Backend Development > How to generate GIF dynamic picture verification code with PHP
How to generate GIF dynamic picture verification code with PHP
- 墨辰丷Original
- 2018-06-06 14:18:421622browse
本篇文章主要介绍PHP如何生成GIF动态图片验证码，感兴趣的朋友参考下，希望对大家有所帮助。
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
/**
* 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 < 3; $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);
}
}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
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, mt_rand(0, 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：调用和显示验证码，在需要添加验证码的页面加入以下代码，代码如下：
<input name="yzm" type="text" class="input1" size="12" style="width:70px;"/>
<SCRIPT LANGUAGE="JavaScript">
<!--
document.write('<img id="yz_Img" name="imageField" class="yz_Img" title="刷新验证码" onclick="this.src=this.src+Math.random();" src="yzimg.php?'+Math.random()+'">');
//-->
</SCRIPT>总结：以上就是本篇文的全部内容，希望能对大家的学习有所帮助。
相关推荐：
PHP数组函数array_multisort()的用法及实例分析
PHP函数import_request_variables()用法及实例分析
PHP函数shuffle()取数组若干个随机元素的方法及实例分析
The above is the detailed content of How to generate GIF dynamic picture verification code with PHP. For more information, please follow other related articles on the PHP Chinese website!
Statement：
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Previous article：ThinkPHP R method exampleNext article：ThinkPHP R method example