php等比缩放上传图片缩略图的代码

2. /**
3. * *
4. *等比缩放
5. * @param unknown_type $srcImage 源图片路径
6. * @param unknown_type $toFile 目标图片路径
7. * @param unknown_type $maxWidth 最大宽
8. * @param unknown_type $maxHeight 最大高
9. * @param unknown_type $imgQuality 图片质量
10. * @return unknown
11. */
12. function resize($srcImage,$toFile,$maxWidth = 100,$maxHeight = 100,$imgQuality=100)
13. {
15. list($width, $height, $type, $attr) = getimagesize($srcImage);
16. if($width switch ($type) {
17. case 1: $img = imagecreatefromgif($srcImage); break;
18. case 2: $img = imagecreatefromjpeg($srcImage); break;
19. case 3: $img = imagecreatefrompng($srcImage); break;
20. }
21. $scale = min($maxWidth/$width, $maxHeight/$height); //求出绽放比例
23. if($scale $newWidth = floor($scale*$width);
24. $newHeight = floor($scale*$height);
25. $newImg = imagecreatetruecolor($newWidth, $newHeight);
26. imagecopyresampled($newImg, $img, 0, 0, 0, 0, $newWidth, $newHeight, $width, $height);
27. $newName = "";
28. $toFile = preg_replace("/(.gif|.jpg|.jpeg|.png)/i","",$toFile);
30. switch($type) {
31. case 1: if(imagegif($newImg, "$toFile$newName.gif", $imgQuality))
32. return "$newName.gif"; break;
33. case 2: if(imagejpeg($newImg, "$toFile$newName.jpg", $imgQuality))
34. return "$newName.jpg"; break;
35. case 3: if(imagepng($newImg, "$toFile$newName.png", $imgQuality))
36. return "$newName.png"; break;
37. default: if(imagejpeg($newImg, "$toFile$newName.jpg", $imgQuality))
38. return "$newName.jpg"; break;
39. }
40. imagedestroy($newImg);
41. }
42. imagedestroy($img);
43. return false;
44. }

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