2023年7月3日发(作者：)

phpgif裁剪,php调整gif动画图⽚尺⼨⽰例代码分享类的使⽤demo：require_once "";$gr = new gifresizer;$gr->temp_dir = "keleyi";$gr->resize("","keleyi_",500,500);?>类的源代码,保存为⽂件：/**** Resizes Animated GIF Files** ///IMPORTANT NOTE: The script needs a temporary directory where all the frames should be extracted.* Create a directory with a 777 permission level and write the path into $temp_dir variable below.** Default directory is "frames".*/class gifresizer {public $temp_dir = "frames";private $pointer = 0;private $index = 0;private $globaldata = array();private $imagedata = array();private $imageinfo = array();private $handle = 0;private $orgvars = array();private $encdata = array();private $parsedfiles = array();private $originalwidth = 0;private $originalheight = 0;private $wr,$hr;private $props = array();private $decoding = false;/*** Public part of the class** @orgfile - Original file path* @newfile - New filename with path* @width - Desired image width* @height - Desired image height*/function resize($orgfile,$newfile,$width,$height){$this->decode($orgfile);$this->wr=$width/$this->originalwidth;$this->hr=$height/$this->originalheight;$this->resizeframes();$this->encode($newfile,$width,$height);$this->clearframes();}/*** GIF Decoder function.* Parses the GIF animation into single frames.*/private function decode($filename){$this->decoding = true;$this->clearvariables();$this->loadfile($filename);$this->get_gif_header();$this->get_graphics_extension(0);$this->get_application_data();$this->get_application_data();$this->get_image_block(0);$this->get_graphics_extension(1);$this->get_comment_data();$this->get_application_data();$this->get_image_block(1);while(!$this->checkbyte(0x3b) && !$this->checkEOF()){$this->get_comment_data(1);$this->get_graphics_extension(2);$this->get_image_block(2);}$this->writeframes(time());$this->closefile();$this->decoding = false;}/*** GIF Encoder function.* Combines the parsed GIF frames into one single animation.*/private function encode($new_filename,$newwidth,$newheight){$mystring = "";$this->pointer = 0;$this->imagedata = array();$this->imageinfo = array();$this->handle = 0;$this->index=0;$k=0;foreach($this->parsedfiles as $imagepart){$this->loadfile($imagepart);$this->get_gif_header();$this->get_application_data();$this->get_comment_data();$this->get_graphics_extension(0);$this->get_image_block(0);//get transparent color index and colorif(isset($this->encdata[$this->index-1]))$gxdata = $this->encdata[$this->index-1]["graphicsextension"];else$gxdata = null;$ghdata = $this->imageinfo["gifheader"];$trcolor = "";$hastransparency=($gxdata[3]&&1==1);if($hastransparency){$trcx = ord($gxdata[6]);$trcolor = substr($ghdata,13+$trcx*3,3);}//global color table to image data;$this->transfercolortable($this->imageinfo["gifheader"],$this->imagedata[$this->index-1]["imagedata"]);$imageblock = &$this->imagedata[$this->index-1]["imagedata"];//if transparency exists transfer transparency indexif($hastransparency){$haslocalcolortable = ((ord($imageblock[9])&128)==128);if($haslocalcolortable){//local table exists. determine boundaries and look for it.$tablesize=(pow(2,(ord($imageblock[9])&7)+1)*3)+10;$this->orgvars[$this->index-1]["transparent_color_index"] =((strrpos(substr($this->imagedata[$this->index-1]["imagedata"],0,$tablesize),$trcolor)-10)/3);}else{//local table doesnt exist, look at the global one.$tablesize=(pow(2,(ord($gxdata[10])&7)+1)*3)+10;$this->orgvars[$this->index-1]["transparent_color_index"] =((strrpos(substr($ghdata,0,$tablesize),$trcolor)-10)/3);}}//apply original delay time,transparent index and disposal values to graphics extensionif(!$this->imagedata[$this->index-1]["graphicsextension"]) $this->imagedata[$this->index-1]["graphicsextension"] =chr(0x21).chr(0xf9).chr(0x04).chr(0x00).chr(0x00).chr(0x00).chr(0x00).chr(0x00);$imagedata = &$this->imagedata[$this->index-1]["graphicsextension"];$imagedata[3] = chr((ord($imagedata[3]) & 0xE3) | ($this->orgvars[$this->index-1]["disposal_method"] << 2));$imagedata[4] = chr(($this->orgvars[$this->index-1]["delay_time"] % 256));$imagedata[5] = chr(floor($this->orgvars[$this->index-1]["delay_time"] / 256));if($hastransparency){$imagedata[6] = chr($this->orgvars[$this->index-1]["transparent_color_index"]);}$imagedata[3] = chr(ord($imagedata[3])|$hastransparency);//apply calculated left and top offset$imageblock[1] = chr(round(($this->orgvars[$this->index-1]["offset_left"]*$this->wr) % 256));$imageblock[2] = chr(floor(($this->orgvars[$this->index-1]["offset_left"]*$this->wr) / 256));$imageblock[3] = chr(round(($this->orgvars[$this->index-1]["offset_top"]*$this->hr) % 256));$imageblock[4] = chr(floor(($this->orgvars[$this->index-1]["offset_top"]*$this->hr) / 256));if($this->index==1){if(!isset($this->imageinfo["applicationdata"]) || !$this->imageinfo["applicationdata"])$this->imageinfo["applicationdata"]=chr(0x21).chr(0xff).chr(0x0b)."NETSCAPE2.0".chr(0x03).chr(0x01).chr(0x00).chr(0x00).chr(0x00);if(!isset($this->imageinfo["commentdata"]) || !$this->imageinfo["commentdata"])$this->imageinfo["commentdata"] = chr(0x21).chr(0xfe).chr(0x10)."PHPGIFRESIZER1.0".chr(0);$mystring .= $this->orgvars["gifheader"]. $this->imageinfo["applicationdata"].$this->imageinfo["commentdata"];if(isset($this->orgvars["hasgx_type_0"]) && $this->orgvars["hasgx_type_0"]) $mystring .= $this->globaldata["graphicsextension_0"];if(isset($this->orgvars["hasgx_type_1"]) && $this->orgvars["hasgx_type_1"]) $mystring .= $this->globaldata["graphicsextension"];}$mystring .= $imagedata . $imageblock;$k++;$this->closefile();}$mystring .= chr(0x3b);//applying new width & height to gif header$mystring[6] = chr($newwidth % 256);$mystring[7] = chr(floor($newwidth / 256));$mystring[8] = chr($newheight % 256);$mystring[9] = chr(floor($newheight / 256));$mystring[11]= $this->orgvars["background_color"];//if(file_exists($new_filename)){unlink($new_filename);}file_put_contents($new_filename,$mystring);}/*** Variable Reset function* If a instance is used multiple times, it's needed. Trust me.*/private function clearvariables(){$this->pointer = 0;$this->index = 0;$this->imagedata = array();$this->imageinfo = array();$this->handle = 0;$this->parsedfiles = array();}/*** Clear Frames function* For deleting the frames after encoding.*/private function clearframes(){foreach($this->parsedfiles as $temp_frame){unlink($temp_frame);}}/*** Frame Writer* Writes the GIF frames into files.*/private function writeframes($prepend){for($i=0;$iimagedata);$i++){file_put_contents($this->temp_dir."/frame_".$prepend."_".str_pad($i,2,"0",STR_PAD_LEFT).".gif",$this->imageinfo["gifheader"].$this->imagedata[$i]["graphicsextension"].$this->imagedata[$i]["imagedata"].chr(0x3b));$this->parsedfiles[]=$this->temp_dir."/frame_".$prepend."_".str_pad($i,2,"0",STR_PAD_LEFT).".gif";}}/*** Color Palette Transfer Device* Transferring Global Color Table (GCT) from frames into Local Color Tables in animation.*/private function transfercolortable($src,&$dst){//src is gif header,dst is image data block//if global color table exists,transfer itif((ord($src[10])&128)==128){//Gif Header Global Color Table Length$ghctl = pow(2,$this->readbits(ord($src[10]),5,3)+1)*3;//cut global color table from gif header$ghgct = substr($src,13,$ghctl);//check image block color table lengthif((ord($dst[9])&128)==128){//Image data contains color table. skip.}else{//Image data needs a color table.//get last color table length so we can truncate the dummy color table$idctl = pow(2,$this->readbits(ord($dst[9]),5,3)+1)*3;//set color table flag and length$dst[9] = chr(ord($dst[9]) | (0x80 | (log($ghctl/3,2)-1)));//inject color table$dst = substr($dst,0,10).$($dst,-1*strlen($dst)+10);}}else{//global color table doesn't exist. skip.}}/*** GIF Parser Functions.* Below functions are the main structure parser components.*/private function get_gif_header(){$this->p_forward(10);if($this->readbits(($mybyte=$this->readbyte_int()),0,1)==1){$this->p_forward(2);$this->p_forward(pow(2,$this->readbits($mybyte,5,3)+1)*3);}else{$this->p_forward(2);}$this->imageinfo["gifheader"]=$this->datapart(0,$this->pointer);if($this->decoding){$this->orgvars["gifheader"]=$this->imageinfo["gifheader"];$this->originalwidth = ord($this->orgvars["gifheader"][7])*256+ord($this->orgvars["gifheader"][6]);$this->originalheight = ord($this->orgvars["gifheader"][9])*256+ord($this->orgvars["gifheader"][8]);$this->orgvars["background_color"]=$this->orgvars["gifheader"][11];}}//-------------------------------------------------------private function get_application_data(){$startdata = $this->readbyte(2);if($startdata==chr(0x21).chr(0xff)){$start = $this->pointer - 2;$this->p_forward($this->readbyte_int());$this->read_data_stream($this->readbyte_int());$this->imageinfo["applicationdata"] = $this->datapart($start,$this->pointer-$start);}else{$this->p_rewind(2);}}//-------------------------------------------------------private function get_comment_data(){$startdata = $this->readbyte(2);if($startdata==chr(0x21).chr(0xfe)){$start = $this->pointer - 2;$this->read_data_stream($this->readbyte_int());$this->imageinfo["commentdata"] = $this->datapart($start,$this->pointer-$start);}else{$this->p_rewind(2);}}//-------------------------------------------------------private function get_graphics_extension($type){$startdata = $this->readbyte(2);if($startdata==chr(0x21).chr(0xf9)){$start = $this->pointer - 2;$this->p_forward($this->readbyte_int());$this->p_forward(1);if($type==2){$this->imagedata[$this->index]["graphicsextension"] = $this->datapart($start,$this->pointer-$start);}else if($type==1){$this->orgvars["hasgx_type_1"] = 1;$this->globaldata["graphicsextension"] = $this->datapart($start,$this->pointer-$start);}else if($type==0 && $this->decoding==false){$this->encdata[$this->index]["graphicsextension"] = $this->datapart($start,$this->pointer-$start);}else if($type==0 && $this->decoding==true){$this->orgvars["hasgx_type_0"] = 1;$this->globaldata["graphicsextension_0"] = $this->datapart($start,$this->pointer-$start);}}else{$this->p_rewind(2);}}//-------------------------------------------------------private function get_image_block($type){if($this->checkbyte(0x2c)){$start = $this->pointer;$this->p_forward(9);if($this->readbits(($mybyte=$this->readbyte_int()),0,1)==1){$this->p_forward(pow(2,$this->readbits($mybyte,5,3)+1)*3);}$this->p_forward(1);$this->read_data_stream($this->readbyte_int());$this->imagedata[$this->index]["imagedata"] = $this->datapart($start,$this->pointer-$start);if($type==0){$this->orgvars["hasgx_type_0"] = 0;if(isset($this->globaldata["graphicsextension_0"]))$this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension_0"];else$this->imagedata[$this->index]["graphicsextension"]=null;unset($this->globaldata["graphicsextension_0"]);}elseif($type==1){if(isset($this->orgvars["hasgx_type_1"]) && $this->orgvars["hasgx_type_1"]==1){$this->orgvars["hasgx_type_1"] = 0;$this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension"];unset($this->globaldata["graphicsextension"]);}else{$this->orgvars["hasgx_type_0"] = 0;$this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension_0"];unset($this->globaldata["graphicsextension_0"]);}}$this->parse_image_data();$this->index++;}}//-------------------------------------------------------private function parse_image_data(){$this->imagedata[$this->index]["disposal_method"] = $this->get_imagedata_bit("ext",3,3,3);$this->imagedata[$this->index]["user_input_flag"] = $this->get_imagedata_bit("ext",3,6,1);$this->imagedata[$this->index]["transparent_color_flag"] = $this->get_imagedata_bit("ext",3,7,1);$this->imagedata[$this->index]["delay_time"] = $this->dualbyteval($this->get_imagedata_byte("ext",4,2));$this->imagedata[$this->index]["transparent_color_index"] = ord($this->get_imagedata_byte("ext",6,1));$this->imagedata[$this->index]["offset_left"] = $this->dualbyteval($this->get_imagedata_byte("dat",1,2));$this->imagedata[$this->index]["offset_top"] = $this->dualbyteval($this->get_imagedata_byte("dat",3,2));$this->imagedata[$this->index]["width"] = $this->dualbyteval($this->get_imagedata_byte("dat",5,2));$this->imagedata[$this->index]["height"] = $this->dualbyteval($this->get_imagedata_byte("dat",7,2));$this->imagedata[$this->index]["local_color_table_flag"] = $this->get_imagedata_bit("dat",9,0,1);$this->imagedata[$this->index]["interlace_flag"] = $this->get_imagedata_bit("dat",9,1,1);$this->imagedata[$this->index]["sort_flag"] = $this->get_imagedata_bit("dat",9,2,1);$this->imagedata[$this->index]["color_table_size"] = pow(2,$this->get_imagedata_bit("dat",9,5,3)+1)*3;$this->imagedata[$this->index]["color_table"] = substr($this->imagedata[$this->index]["imagedata"],10,$this->imagedata[$this->index]["color_table_size"]);$this->imagedata[$this->index]["lzw_code_size"] = ord($this->get_imagedata_byte("dat",10,1));if($this->decoding){$this->orgvars[$this->index]["transparent_color_flag"] = $this->imagedata[$this->index]["transparent_color_flag"];$this->orgvars[$this->index]["transparent_color_index"] = $this->imagedata[$this->index]["transparent_color_index"];$this->orgvars[$this->index]["delay_time"] = $this->imagedata[$this->index]["delay_time"];$this->orgvars[$this->index]["disposal_method"] = $this->imagedata[$this->index]["disposal_method"];$this->orgvars[$this->index]["offset_left"] = $this->imagedata[$this->index]["offset_left"];$this->orgvars[$this->index]["offset_top"] = $this->imagedata[$this->index]["offset_top"];}}//-------------------------------------------------------private function get_imagedata_byte($type,$start,$length){if($type=="ext")return substr($this->imagedata[$this->index]["graphicsextension"],$start,$length);elseif($type=="dat")return substr($this->imagedata[$this->index]["imagedata"],$start,$length);}//-------------------------------------------------------private function get_imagedata_bit($type,$byteindex,$bitstart,$bitlength){if($type=="ext")return $this->readbits(ord(substr($this->imagedata[$this->index]["graphicsextension"],$byteindex,1)),$bitstart,$bitlength);elseif($type=="dat")return $this->readbits(ord(substr($this->imagedata[$this->index]["imagedata"],$byteindex,1)),$bitstart,$bitlength);}//-------------------------------------------------------private function dualbyteval($s){$i = ord($s[1])*256 + ord($s[0]);return $i;}//------------ Helper Functions ---------------------private function read_data_stream($first_length){$this->p_forward($first_length);$length=$this->readbyte_int();if($length!=0) {while($length!=0){$this->p_forward($length);$length=$this->readbyte_int();}}return true;}//-------------------------------------------------------private function loadfile($filename){$this->handle = fopen($filename,"rb");$this->pointer = 0;}//-------------------------------------------------------private function closefile(){fclose($this->handle);$this->handle=0;}//-------------------------------------------------------private function readbyte($byte_count){$data = fread($this->handle,$byte_count);$this->pointer += $byte_count;return $data;}//-------------------------------------------------------private function readbyte_int(){$data = fread($this->handle,1);$this->pointer++;return ord($data);}//-------------------------------------------------------private function readbits($byte,$start,$length){$bin = str_pad(decbin($byte),8,"0",STR_PAD_LEFT);$data = substr($bin,$start,$length);return bindec($data);}//-------------------------------------------------------private function p_rewind($length){$this->pointer-=$length;fseek($this->handle,$this->pointer);}//-------------------------------------------------------private function p_forward($length){$this->pointer+=$length;fseek($this->handle,$this->pointer);}//-------------------------------------------------------private function datapart($start,$length){fseek($this->handle,$start);$data = fread($this->handle,$length);fseek($this->handle,$this->pointer);return $data;}//-------------------------------------------------------private function checkbyte($byte){if(fgetc($this->handle)==chr($byte)){fseek($this->handle,$this->pointer);return true;}else{fseek($this->handle,$this->pointer);return false;}}//-------------------------------------------------------private function checkEOF(){if(fgetc($this->handle)===false){return true;}else{fseek($this->handle,$this->pointer);return false;}}//-------------------------------------------------------/*** Debug Functions. * Parses the GIF animation into single frames.*/private function debug($string){echo "";for($i=0;$iecho str_pad(dechex(ord($string[$i])),2,"0",STR_PAD_LEFT). " ";}echo "";}//-------------------------------------------------------private function debuglen($var,$len){echo "";for($i=0;$iecho str_pad(dechex(ord($var[$i])),2,"0",STR_PAD_LEFT). " ";}echo "";}//-------------------------------------------------------private function debugstream($length){$this->debug($this->datapart($this->pointer,$length));}//-------------------------------------------------------/*** GD Resizer Device* Resizes the animation frames*/private function resizeframes(){$k=0;foreach($this->parsedfiles as $img){$src = imagecreatefromgif($img);$sw = $this->imagedata[$k]["width"];$sh = $this->imagedata[$k]["height"];$nw = round($sw * $this->wr);$nh = round($sh * $this->hr);$sprite = imagecreatetruecolor($nw,$nh);$trans = imagecolortransparent($sprite);imagealphablending($sprite, false);imagesavealpha($sprite, true);imagepalettecopy($sprite,$src);imagefill($sprite,0,0,imagecolortransparent($src));imagecolortransparent($sprite,imagecolortransparent($src));imagecopyresized($sprite,$src,0,0,0,0,$nw,$nh,$sw,$sh);imagegif($sprite,$img);imagedestroy($sprite);imagedestroy($src);$k++;}}}?>