一个很实用的类,php调整gif图片的尺寸!

WBOY
Lepaskan: 2016-07-25 08:49:17
asal
1241 orang telah melayarinya
这个类可以对GIF格式的动态文件进行调整。提取动态图片帧文件到一个临时目录中。调整图像的大小并提取和重建成动画的GIF格式的新文件。

@红薯不让传gif图片
效果查看:http://www.codepearl.com/files/187.html 一个很实用的类,php调整gif图片的尺寸!
  1. //http://www.codepearl.com
  2. require_once "gifresizer.php";
  3. $gr = new gifresizer;
  4. $gr->temp_dir = "codepearl";
  5. $gr->resize("codepearl.gif","codepearl_resized.gif",500,500);
  6. ?>
复制代码
  1. /**
  2. * http://www.codepearl.com
  3. * Resizes Animated GIF Files
  4. *
  5. * ///IMPORTANT NOTE: The script needs a temporary directory where all the frames should be extracted.
  6. * Create a directory with a 777 permission level and write the path into $temp_dir variable below.
  7. *
  8. * Default directory is "frames".
  9. */
  10. class gifresizer {
  11. public $temp_dir = "frames";
  12. private $pointer = 0;
  13. private $index = 0;
  14. private $globaldata = array();
  15. private $imagedata = array();
  16. private $imageinfo = array();
  17. private $handle = 0;
  18. private $orgvars = array();
  19. private $encdata = array();
  20. private $parsedfiles = array();
  21. private $originalwidth = 0;
  22. private $originalheight = 0;
  23. private $wr,$hr;
  24. private $props = array();
  25. private $decoding = false;
  26. /**
  27. * Public part of the class
  28. *
  29. * @orgfile - Original file path
  30. * @newfile - New filename with path
  31. * @width - Desired image width
  32. * @height - Desired image height
  33. */
  34. function resize($orgfile,$newfile,$width,$height){
  35. $this->decode($orgfile);
  36. $this->wr=$width/$this->originalwidth;
  37. $this->hr=$height/$this->originalheight;
  38. $this->resizeframes();
  39. $this->encode($newfile,$width,$height);
  40. $this->clearframes();
  41. }
  42. /**
  43. * GIF Decoder function.
  44. * Parses the GIF animation into single frames.
  45. */
  46. private function decode($filename){
  47. $this->decoding = true;
  48. $this->clearvariables();
  49. $this->loadfile($filename);
  50. $this->get_gif_header();
  51. $this->get_graphics_extension(0);
  52. $this->get_application_data();
  53. $this->get_application_data();
  54. $this->get_image_block(0);
  55. $this->get_graphics_extension(1);
  56. $this->get_comment_data();
  57. $this->get_application_data();
  58. $this->get_image_block(1);
  59. while(!$this->checkbyte(0x3b) && !$this->checkEOF()){
  60. $this->get_comment_data(1);
  61. $this->get_graphics_extension(2);
  62. $this->get_image_block(2);
  63. }
  64. $this->writeframes(time());
  65. $this->closefile();
  66. $this->decoding = false;
  67. }
  68. /**
  69. * GIF Encoder function.
  70. * Combines the parsed GIF frames into one single animation.
  71. */
  72. private function encode($new_filename,$newwidth,$newheight){
  73. $mystring = "";
  74. $this->pointer = 0;
  75. $this->imagedata = array();
  76. $this->imageinfo = array();
  77. $this->handle = 0;
  78. $this->index=0;
  79. $k=0;
  80. foreach($this->parsedfiles as $imagepart){
  81. $this->loadfile($imagepart);
  82. $this->get_gif_header();
  83. $this->get_application_data();
  84. $this->get_comment_data();
  85. $this->get_graphics_extension(0);
  86. $this->get_image_block(0);
  87. //get transparent color index and color
  88. if(isset($this->encdata[$this->index-1]))
  89. $gxdata = $this->encdata[$this->index-1]["graphicsextension"];
  90. else
  91. $gxdata = null;
  92. $ghdata = $this->imageinfo["gifheader"];
  93. $trcolor = "";
  94. $hastransparency=($gxdata[3]&&1==1);
  95. if($hastransparency){
  96. $trcx = ord($gxdata[6]);
  97. $trcolor = substr($ghdata,13+$trcx*3,3);
  98. }
  99. //global color table to image data;
  100. $this->transfercolortable($this->imageinfo["gifheader"],$this->imagedata[$this->index-1]["imagedata"]);
  101. $imageblock = &$this->imagedata[$this->index-1]["imagedata"];
  102. //if transparency exists transfer transparency index
  103. if($hastransparency){
  104. $haslocalcolortable = ((ord($imageblock[9])&128)==128);
  105. if($haslocalcolortable){
  106. //local table exists. determine boundaries and look for it.
  107. $tablesize=(pow(2,(ord($imageblock[9])&7)+1)*3)+10;
  108. $this->orgvars[$this->index-1]["transparent_color_index"] =
  109. ((strrpos(substr($this->imagedata[$this->index-1]["imagedata"],0,$tablesize),$trcolor)-10)/3);
  110. }else{
  111. //local table doesnt exist, look at the global one.
  112. $tablesize=(pow(2,(ord($gxdata[10])&7)+1)*3)+10;
  113. $this->orgvars[$this->index-1]["transparent_color_index"] =
  114. ((strrpos(substr($ghdata,0,$tablesize),$trcolor)-10)/3);
  115. }
  116. }
  117. //apply original delay time,transparent index and disposal values to graphics extension
  118. if(!$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);
  119. $imagedata = &$this->imagedata[$this->index-1]["graphicsextension"];
  120. $imagedata[3] = chr((ord($imagedata[3]) & 0xE3) | ($this->orgvars[$this->index-1]["disposal_method"] $imagedata[4] = chr(($this->orgvars[$this->index-1]["delay_time"] % 256));
  121. $imagedata[5] = chr(floor($this->orgvars[$this->index-1]["delay_time"] / 256));
  122. if($hastransparency){
  123. $imagedata[6] = chr($this->orgvars[$this->index-1]["transparent_color_index"]);
  124. }
  125. $imagedata[3] = chr(ord($imagedata[3])|$hastransparency);
  126. //apply calculated left and top offset
  127. $imageblock[1] = chr(round(($this->orgvars[$this->index-1]["offset_left"]*$this->wr) % 256));
  128. $imageblock[2] = chr(floor(($this->orgvars[$this->index-1]["offset_left"]*$this->wr) / 256));
  129. $imageblock[3] = chr(round(($this->orgvars[$this->index-1]["offset_top"]*$this->hr) % 256));
  130. $imageblock[4] = chr(floor(($this->orgvars[$this->index-1]["offset_top"]*$this->hr) / 256));
  131. if($this->index==1){
  132. if(!isset($this->imageinfo["applicationdata"]) || !$this->imageinfo["applicationdata"])
  133. $this->imageinfo["applicationdata"]=chr(0x21).chr(0xff).chr(0x0b)."NETSCAPE2.0".chr(0x03).chr(0x01).chr(0x00).chr(0x00).chr(0x00);
  134. if(!isset($this->imageinfo["commentdata"]) || !$this->imageinfo["commentdata"])
  135. $this->imageinfo["commentdata"] = chr(0x21).chr(0xfe).chr(0x10)."PHPGIFRESIZER1.0".chr(0);
  136. $mystring .= $this->orgvars["gifheader"]. $this->imageinfo["applicationdata"].$this->imageinfo["commentdata"];
  137. if(isset($this->orgvars["hasgx_type_0"]) && $this->orgvars["hasgx_type_0"]) $mystring .= $this->globaldata["graphicsextension_0"];
  138. if(isset($this->orgvars["hasgx_type_1"]) && $this->orgvars["hasgx_type_1"]) $mystring .= $this->globaldata["graphicsextension"];
  139. }
  140. $mystring .= $imagedata . $imageblock;
  141. $k++;
  142. $this->closefile();
  143. }
  144. $mystring .= chr(0x3b);
  145. //applying new width & height to gif header
  146. $mystring[6] = chr($newwidth % 256);
  147. $mystring[7] = chr(floor($newwidth / 256));
  148. $mystring[8] = chr($newheight % 256);
  149. $mystring[9] = chr(floor($newheight / 256));
  150. $mystring[11]= $this->orgvars["background_color"];
  151. //if(file_exists($new_filename)){unlink($new_filename);}
  152. file_put_contents($new_filename,$mystring);
  153. }
  154. /**
  155. * Variable Reset function
  156. * If a instance is used multiple times, it's needed. Trust me.
  157. */
  158. private function clearvariables(){
  159. $this->pointer = 0;
  160. $this->index = 0;
  161. $this->imagedata = array();
  162. $this->imageinfo = array();
  163. $this->handle = 0;
  164. $this->parsedfiles = array();
  165. }
  166. /**
  167. * Clear Frames function
  168. * For deleting the frames after encoding.
  169. */
  170. private function clearframes(){
  171. foreach($this->parsedfiles as $temp_frame){
  172. unlink($temp_frame);
  173. }
  174. }
  175. /**
  176. * Frame Writer
  177. * Writes the GIF frames into files.
  178. */
  179. private function writeframes($prepend){
  180. for($i=0;$iimagedata);$i++){
  181. 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));
  182. $this->parsedfiles[]=$this->temp_dir."/frame_".$prepend."_".str_pad($i,2,"0",STR_PAD_LEFT).".gif";
  183. }
  184. }
  185. /**
  186. * Color Palette Transfer Device
  187. * Transferring Global Color Table (GCT) from frames into Local Color Tables in animation.
  188. */
  189. private function transfercolortable($src,&$dst){
  190. //src is gif header,dst is image data block
  191. //if global color table exists,transfer it
  192. if((ord($src[10])&128)==128){
  193. //Gif Header Global Color Table Length
  194. $ghctl = pow(2,$this->readbits(ord($src[10]),5,3)+1)*3;
  195. //cut global color table from gif header
  196. $ghgct = substr($src,13,$ghctl);
  197. //check image block color table length
  198. if((ord($dst[9])&128)==128){
  199. //Image data contains color table. skip.
  200. }else{
  201. //Image data needs a color table.
  202. //get last color table length so we can truncate the dummy color table
  203. $idctl = pow(2,$this->readbits(ord($dst[9]),5,3)+1)*3;
  204. //set color table flag and length
  205. $dst[9] = chr(ord($dst[9]) | (0x80 | (log($ghctl/3,2)-1)));
  206. //inject color table
  207. $dst = substr($dst,0,10).$ghgct.substr($dst,-1*strlen($dst)+10);
  208. }
  209. }else{
  210. //global color table doesn't exist. skip.
  211. }
  212. }
  213. /**
  214. * GIF Parser Functions.
  215. * Below functions are the main structure parser components.
  216. */
  217. private function get_gif_header(){
  218. $this->p_forward(10);
  219. if($this->readbits(($mybyte=$this->readbyte_int()),0,1)==1){
  220. $this->p_forward(2);
  221. $this->p_forward(pow(2,$this->readbits($mybyte,5,3)+1)*3);
  222. }else{
  223. $this->p_forward(2);
  224. }
  225. $this->imageinfo["gifheader"]=$this->datapart(0,$this->pointer);
  226. if($this->decoding){
  227. $this->orgvars["gifheader"]=$this->imageinfo["gifheader"];
  228. $this->originalwidth = ord($this->orgvars["gifheader"][7])*256+ord($this->orgvars["gifheader"][6]);
  229. $this->originalheight = ord($this->orgvars["gifheader"][9])*256+ord($this->orgvars["gifheader"][8]);
  230. $this->orgvars["background_color"]=$this->orgvars["gifheader"][11];
  231. }
  232. }
  233. //-------------------------------------------------------
  234. private function get_application_data(){
  235. $startdata = $this->readbyte(2);
  236. if($startdata==chr(0x21).chr(0xff)){
  237. $start = $this->pointer - 2;
  238. $this->p_forward($this->readbyte_int());
  239. $this->read_data_stream($this->readbyte_int());
  240. $this->imageinfo["applicationdata"] = $this->datapart($start,$this->pointer-$start);
  241. }else{
  242. $this->p_rewind(2);
  243. }
  244. }
  245. //-------------------------------------------------------
  246. private function get_comment_data(){
  247. $startdata = $this->readbyte(2);
  248. if($startdata==chr(0x21).chr(0xfe)){
  249. $start = $this->pointer - 2;
  250. $this->read_data_stream($this->readbyte_int());
  251. $this->imageinfo["commentdata"] = $this->datapart($start,$this->pointer-$start);
  252. }else{
  253. $this->p_rewind(2);
  254. }
  255. }
  256. //-------------------------------------------------------
  257. private function get_graphics_extension($type){
  258. $startdata = $this->readbyte(2);
  259. if($startdata==chr(0x21).chr(0xf9)){
  260. $start = $this->pointer - 2;
  261. $this->p_forward($this->readbyte_int());
  262. $this->p_forward(1);
  263. if($type==2){
  264. $this->imagedata[$this->index]["graphicsextension"] = $this->datapart($start,$this->pointer-$start);
  265. }else if($type==1){
  266. $this->orgvars["hasgx_type_1"] = 1;
  267. $this->globaldata["graphicsextension"] = $this->datapart($start,$this->pointer-$start);
  268. }else if($type==0 && $this->decoding==false){
  269. $this->encdata[$this->index]["graphicsextension"] = $this->datapart($start,$this->pointer-$start);
  270. }else if($type==0 && $this->decoding==true){
  271. $this->orgvars["hasgx_type_0"] = 1;
  272. $this->globaldata["graphicsextension_0"] = $this->datapart($start,$this->pointer-$start);
  273. }
  274. }else{
  275. $this->p_rewind(2);
  276. }
  277. }
  278. //-------------------------------------------------------
  279. private function get_image_block($type){
  280. if($this->checkbyte(0x2c)){
  281. $start = $this->pointer;
  282. $this->p_forward(9);
  283. if($this->readbits(($mybyte=$this->readbyte_int()),0,1)==1){
  284. $this->p_forward(pow(2,$this->readbits($mybyte,5,3)+1)*3);
  285. }
  286. $this->p_forward(1);
  287. $this->read_data_stream($this->readbyte_int());
  288. $this->imagedata[$this->index]["imagedata"] = $this->datapart($start,$this->pointer-$start);
  289. if($type==0){
  290. $this->orgvars["hasgx_type_0"] = 0;
  291. if(isset($this->globaldata["graphicsextension_0"]))
  292. $this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension_0"];
  293. else
  294. $this->imagedata[$this->index]["graphicsextension"]=null;
  295. unset($this->globaldata["graphicsextension_0"]);
  296. }elseif($type==1){
  297. if(isset($this->orgvars["hasgx_type_1"]) && $this->orgvars["hasgx_type_1"]==1){
  298. $this->orgvars["hasgx_type_1"] = 0;
  299. $this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension"];
  300. unset($this->globaldata["graphicsextension"]);
  301. }else{
  302. $this->orgvars["hasgx_type_0"] = 0;
  303. $this->imagedata[$this->index]["graphicsextension"]=$this->globaldata["graphicsextension_0"];
  304. unset($this->globaldata["graphicsextension_0"]);
  305. }
  306. }
  307. $this->parse_image_data();
  308. $this->index++;
  309. }
  310. }
  311. //-------------------------------------------------------
  312. private function parse_image_data(){
  313. $this->imagedata[$this->index]["disposal_method"] = $this->get_imagedata_bit("ext",3,3,3);
  314. $this->imagedata[$this->index]["user_input_flag"] = $this->get_imagedata_bit("ext",3,6,1);
  315. $this->imagedata[$this->index]["transparent_color_flag"] = $this->get_imagedata_bit("ext",3,7,1);
  316. $this->imagedata[$this->index]["delay_time"] = $this->dualbyteval($this->get_imagedata_byte("ext",4,2));
  317. $this->imagedata[$this->index]["transparent_color_index"] = ord($this->get_imagedata_byte("ext",6,1));
  318. $this->imagedata[$this->index]["offset_left"] = $this->dualbyteval($this->get_imagedata_byte("dat",1,2));
  319. $this->imagedata[$this->index]["offset_top"] = $this->dualbyteval($this->get_imagedata_byte("dat",3,2));
  320. $this->imagedata[$this->index]["width"] = $this->dualbyteval($this->get_imagedata_byte("dat",5,2));
  321. $this->imagedata[$this->index]["height"] = $this->dualbyteval($this->get_imagedata_byte("dat",7,2));
  322. $this->imagedata[$this->index]["local_color_table_flag"] = $this->get_imagedata_bit("dat",9,0,1);
  323. $this->imagedata[$this->index]["interlace_flag"] = $this->get_imagedata_bit("dat",9,1,1);
  324. $this->imagedata[$this->index]["sort_flag"] = $this->get_imagedata_bit("dat",9,2,1);
  325. $this->imagedata[$this->index]["color_table_size"] = pow(2,$this->get_imagedata_bit("dat",9,5,3)+1)*3;
  326. $this->imagedata[$this->index]["color_table"] = substr($this->imagedata[$this->index]["imagedata"],10,$this->imagedata[$this->index]["color_table_size"]);
  327. $this->imagedata[$this->index]["lzw_code_size"] = ord($this->get_imagedata_byte("dat",10,1));
  328. if($this->decoding){
  329. $this->orgvars[$this->index]["transparent_color_flag"] = $this->imagedata[$this->index]["transparent_color_flag"];
  330. $this->orgvars[$this->index]["transparent_color_index"] = $this->imagedata[$this->index]["transparent_color_index"];
  331. $this->orgvars[$this->index]["delay_time"] = $this->imagedata[$this->index]["delay_time"];
  332. $this->orgvars[$this->index]["disposal_method"] = $this->imagedata[$this->index]["disposal_method"];
  333. $this->orgvars[$this->index]["offset_left"] = $this->imagedata[$this->index]["offset_left"];
  334. $this->orgvars[$this->index]["offset_top"] = $this->imagedata[$this->index]["offset_top"];
  335. }
  336. }
  337. //-------------------------------------------------------
  338. private function get_imagedata_byte($type,$start,$length){
  339. if($type=="ext")
  340. return substr($this->imagedata[$this->index]["graphicsextension"],$start,$length);
  341. elseif($type=="dat")
  342. return substr($this->imagedata[$this->index]["imagedata"],$start,$length);
  343. }
  344. //-------------------------------------------------------
  345. private function get_imagedata_bit($type,$byteindex,$bitstart,$bitlength){
  346. if($type=="ext")
  347. return $this->readbits(ord(substr($this->imagedata[$this->index]["graphicsextension"],$byteindex,1)),$bitstart,$bitlength);
  348. elseif($type=="dat")
  349. return $this->readbits(ord(substr($this->imagedata[$this->index]["imagedata"],$byteindex,1)),$bitstart,$bitlength);
  350. }
  351. //-------------------------------------------------------
  352. private function dualbyteval($s){
  353. $i = ord($s[1])*256 + ord($s[0]);
  354. return $i;
  355. }
  356. //------------ Helper Functions ---------------------
  357. private function read_data_stream($first_length){
  358. $this->p_forward($first_length);
  359. $length=$this->readbyte_int();
  360. if($length!=0) {
  361. while($length!=0){
  362. $this->p_forward($length);
  363. $length=$this->readbyte_int();
  364. }
  365. }
  366. return true;
  367. }
  368. //-------------------------------------------------------
  369. private function loadfile($filename){
  370. $this->handle = fopen($filename,"rb");
  371. $this->pointer = 0;
  372. }
  373. //-------------------------------------------------------
  374. private function closefile(){
  375. fclose($this->handle);
  376. $this->handle=0;
  377. }
  378. //-------------------------------------------------------
  379. private function readbyte($byte_count){
  380. $data = fread($this->handle,$byte_count);
  381. $this->pointer += $byte_count;
  382. return $data;
  383. }
  384. //-------------------------------------------------------
  385. private function readbyte_int(){
  386. $data = fread($this->handle,1);
  387. $this->pointer++;
  388. return ord($data);
  389. }
  390. //-------------------------------------------------------
  391. private function readbits($byte,$start,$length){
  392. $bin = str_pad(decbin($byte),8,"0",STR_PAD_LEFT);
  393. $data = substr($bin,$start,$length);
  394. return bindec($data);
  395. }
  396. //-------------------------------------------------------
  397. private function p_rewind($length){
  398. $this->pointer-=$length;
  399. fseek($this->handle,$this->pointer);
  400. }
  401. //-------------------------------------------------------
  402. private function p_forward($length){
  403. $this->pointer+=$length;
  404. fseek($this->handle,$this->pointer);
  405. }
  406. //-------------------------------------------------------
  407. private function datapart($start,$length){
  408. fseek($this->handle,$start);
  409. $data = fread($this->handle,$length);
  410. fseek($this->handle,$this->pointer);
  411. return $data;
  412. }
  413. //-------------------------------------------------------
  414. private function checkbyte($byte){
  415. if(fgetc($this->handle)==chr($byte)){
  416. fseek($this->handle,$this->pointer);
  417. return true;
  418. }else{
  419. fseek($this->handle,$this->pointer);
  420. return false;
  421. }
  422. }
  423. //-------------------------------------------------------
  424. private function checkEOF(){
  425. if(fgetc($this->handle)===false){
  426. return true;
  427. }else{
  428. fseek($this->handle,$this->pointer);
  429. return false;
  430. }
  431. }
  432. //-------------------------------------------------------
  433. /**
  434. * Debug Functions.
  435. * Parses the GIF animation into single frames.
  436. */
  437. private function debug($string){
  438. echo "
    ";
    Salin selepas log masuk
    Salin selepas log masuk
  439. for($i=0;$i echo str_pad(dechex(ord($string[$i])),2,"0",STR_PAD_LEFT). " ";
  440. }
  441. echo "";
  442. }
  443. //-------------------------------------------------------
  444. private function debuglen($var,$len){
  445. echo "
    ";
    Salin selepas log masuk
    Salin selepas log masuk
  446. for($i=0;$i echo str_pad(dechex(ord($var[$i])),2,"0",STR_PAD_LEFT). " ";
  447. }
  448. echo "";
  449. }
  450. //-------------------------------------------------------
  451. private function debugstream($length){
  452. $this->debug($this->datapart($this->pointer,$length));
  453. }
  454. //-------------------------------------------------------
  455. /**
  456. * GD Resizer Device
  457. * Resizes the animation frames
  458. */
  459. private function resizeframes(){
  460. $k=0;
  461. foreach($this->parsedfiles as $img){
  462. $src = imagecreatefromgif($img);
  463. $sw = $this->imagedata[$k]["width"];
  464. $sh = $this->imagedata[$k]["height"];
  465. $nw = round($sw * $this->wr);
  466. $nh = round($sh * $this->hr);
  467. $sprite = imagecreatetruecolor($nw,$nh);
  468. $trans = imagecolortransparent($sprite);
  469. imagealphablending($sprite, false);
  470. imagesavealpha($sprite, true);
  471. imagepalettecopy($sprite,$src);
  472. imagefill($sprite,0,0,imagecolortransparent($src));
  473. imagecolortransparent($sprite,imagecolortransparent($src));
  474. imagecopyresized($sprite,$src,0,0,0,0,$nw,$nh,$sw,$sh);
  475. imagegif($sprite,$img);
  476. imagedestroy($sprite);
  477. imagedestroy($src);
  478. $k++;
  479. }
  480. }
  481. }
  482. ?>
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