这篇文章主要介绍了PHP使用GIFEncoder类处理gif图片实例,包含解码GIF图片、处理后再次生成GIF图片例子,需要的朋友可以参考下
下面贴处理的源代码：
复制代码代码如下:PHP 8.5.5 PHP 8.5.5 是 PHP 8.5 分支的维护更新版本。该版本延续了“小步快跑”的迭代逻辑，通过深度错误修复、底层性能微调以及安全加固，旨在为开发者提供一个更健壮、更高效的运行环境。该版本严格遵守语义化版本规范，不包含破坏性变更。
下载php require_once("gifencoder.php"); //载入编码 文件$gif = new GIFEncoder(); //实例化gif解码对象$gif->load("test.gif"); //载入要解码的gif图像for($i=0;$i IMGS["frames"]);$i++){ //根据 gif图像的帧数获取每帧的图像数据$im = imagecreatefromstring($gif->getgif($i)); //利用GD库函数将GIF转得标准些imagegif($im, $i.".gif"); //用文件形式保存生成的每帧图像数据，当然也可以用变量}imagedestroy($im);ob_start();for($i=0;sizeof($gif->IMGS["frames"]);$i++){$im=imagecreatefromgif("0.gif"); //根据每帧的图片创建图像if($i>0){ //不是第一帧 复制图片和第一帧合并$frame=imagecreatefromgif("$i.gif"); //读取当前帧的图像$w = imagesx($frame); //获取图像宽度$y= imagesy($frame); //获取图像高度imagecopy($im,$frame,0,0,0,0,$w,$y); //把当前帧图像和第一帧图像复制合并imagedestroy($frame); //销毁当前图像}imagejpeg($im,$i."frame.jpg"); //合并后保存为jpg格式$im=imagecreatefromjpeg($i."frame.jpg"); //从jpg格式重新创建图像imagegif($im); //转为gif格式imagedestroy($im); //销毁图像$imagedata[] = ob_get_contents(); //创建这一帧的图像数据ob_clean();}$diy[]=0;//开始延迟时间$gif = new GIFEncoder($imagedata,$diy,0,2,0,0,0,"bin"); //实例化gif编码对象ob_start();Header ('Content-type:image/gif');echo $gif->GetAnimation();?>以上代码 基本就是一个完整的 读取一个gif图片，对其进行解码，，然后再编码成gif图片的完整过程了..
有了这个就可以在网上随意抓取gif图片然后进行修改。甚至直接用php就可以自己制作一些gif图片.
GIFEncoder类源码：复制代码代码如下: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 $ERR = Array ('ERR00' =>"Does not supported function for only one image!",'ERR01' =>"Source is not a GIF image!",'ERR02' =>"Unintelligible flag ",'ERR03' =>"Could not make animation from animated GIF source",);/*::::::::::::::::::::::::::::::::::::::::::::::::::::::: GIFEncoder...
::*/ function GIFEncoder ($GIF_src, $GIF_dly, $GIF_lop, $GIF_dis,$GIF_red, $GIF_grn, $GIF_blu, $GIF_mod) {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 ) ? ( ( $GIF_dis$this->COL = ( $GIF_red > -1 && $GIF_grn > -1 && $GIF_blu > -1 ) ?( $GIF_red | ( $GIF_grn for ( $i = 0; $i if ( strToLower ( $GIF_mod ) == "url" ) {$this->BUF [ ] = fread ( fopen ( $GIF_src [ $i ], "rb" ), filesize ( $GIF_src [ $i ] ) );}else if ( 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 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; $i BUF ); $i++ ) {GIFEncoder::GIFAddFrames ( $i, $GIF_dly [ $i ] );}GIFEncoder::GIFAddFooter ( );}/*::::::::::::::::::::::::::::::::::::::::::::::::::::::: GIFAddHeader...
::*/ function GIFAddHeader ( ) {$cmap = 0;if ( ord ( $this->BUF [ 0 ] { 10 } ) & 0x80 ) {$cmap = 3 * ( 2 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";}}/*::::::::::::::::::::::::::::::::::::::::::::::::::::::: GIFAddFrames...
::*/ function GIFAddFrames ( $i, $d ) {$Locals_str = 13 + 3 * ( 2 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 BUF [ 0 ] { 10 } ) & 0x07 );$Locals_len = 2 BUF [ $i ] { 10 } ) & 0x07 );$Global_rgb = substr ( $this->BUF [ 0 ], 13,3 * ( 2 BUF [ 0 ] { 10 } ) & 0x07 ) ) );$Locals_rgb = substr ( $this->BUF [ $i ], 13,3 * ( 2 BUF [ $i ] { 10 } ) & 0x07 ) ) );$Locals_ext = "!/xF9/x04" . chr ( ( $this->DIS chr ( ( $d >> 0 ) & 0xFF ) . chr ( ( $d >> 8 ) & 0xFF ) . "/x0/x0";if ( $this->COL > -1 && ord ( $this->BUF [ $i ] { 10 } ) & 0x80 ) {for ( $j = 0; $j 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 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;}/*::::::::::::::::::::::::::::::::::::::::::::::::::::::: GIFAddFooter...
::*/ function GIFAddFooter ( ) {$this->GIF .= ";";}/*::::::::::::::::::::::::::::::::::::::::::::::::::::::: GIFBlockCompare...
::*/ function GIFBlockCompare ( $GlobalBlock, $LocalBlock, $Len ) {for ( $i = 0; $i if ($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 );}/*::::::::::::::::::::::::::::::::::::::::::::::::::::::: GIFWord...
::*/ function GIFWord ( $int ) {return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) );}/*::::::::::::::::::::::::::::::::::::::::::::::::::::::: GetAnimation...
::*/ function GetAnimation ( ) {return ( $this->GIF );}}?>