PHP使用GIFEncoder类处理gif图片实例

下面贴处理的源代码：

代码如下:

load("test.gif"); //载入要解码的gif图像 for($i=0;$iIMGS["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,$w,$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,2,"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：

代码如下:

"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 < 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; $i < count ( $GIF_src ); $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->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; $i < count ( $this->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 << ( 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"; } } /* ::::::::::::::::::::::::::::::::::::::::::::::::::: :: :: GIFAddFrames... :: */ 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; } /* ::::::::::::::::::::::::::::::::::::::::::::::::::: :: :: GIFAddFooter... :: */ function GIFAddFooter ( ) { $this->GIF .= ";"; } /* ::::::::::::::::::::::::::::::::::::::::::::::::::: :: :: GIFBlockCompare... :: */ 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 ); } /* ::::::::::::::::::::::::::::::::::::::::::::::::::: :: :: GIFWord... :: */ function GIFWord ( $int ) { return ( chr ( $int & 0xFF ) . chr ( ( $int >> 8 ) & 0xFF ) ); } /* ::::::::::::::::::::::::::::::::::::::::::::::::::: :: :: GetAnimation... :: */ function GetAnimation ( ) { return ( $this->GIF ); } } ?>