01.function resize($img, $w, $h, $newfilename) {
02.
03.
04. if (!extension_loaded('gd') && !extension_loaded('gd2')) {
05. trigger_error("GD is not loaded", E_USER_WARNING);
06. return false;
07. }
08.
09.
10. $imgInfo = getimagesize($img);
11. switch ($imgInfo[2]) {
12. case 1: $im = imagecreatefromgif($img); break;
13. case 2: $im = imagecreatefromjpeg($img); break;
14. case 3: $im = imagecreatefrompng($img); break;
15. default: trigger_error('Unsupported filetype!', E_USER_WARNING); break;
16. }
17.
18.
19. if ($imgInfo[0] <= $w && $imgInfo[1] $h/$imgInfo[1]) {
20. $nWidth = $w;
21. $nHeight = $imgInfo[1]*($w/$imgInfo[0]);
22. }else{
23. $nWidth = $imgInfo[0]*($h/$imgInfo[1]);
24. $nHeight = $h;
25. }
26. }
27. $nWidth = round($nWidth);
28. $nHeight = round($nHeight);
29.
30. $newImg = imagecreatetruecolor($nWidth, $nHeight);
31.
32.
33. if(($imgInfo[2] == 1) OR ($imgInfo[2]==3)){
34. imagealphablending($newImg, false);
35. imagesavealpha($newImg,true);
36. $transparent = imagecolorallocatealpha($newImg, 255, 255, 255, 127);
37. imagefilledrectangle($newImg, 0, 0, $nWidth, $nHeight, $transparent);
38. }
39. imagecopyresampled($newImg, $im, 0, 0, 0, 0, $nWidth, $nHeight, $imgInfo[0], $imgInfo[1]);
40.
41.
42. switch ($imgInfo[2]) {
43. case 1: imagegif($newImg,$newfilename); break;
44. case 2: imagejpeg($newImg,$newfilename); break;
45. case 3: imagepng($newImg,$newfilename); break;
46. default: trigger_error('Failed resize image!', E_USER_WARNING); break;
47. }
48.
49. return $newfilename;
50.}
