这个程序很实用,但只是用来生成等比例生成缩略图,你要把文件上传到服务器,然后再由此函数来操作,有需要的朋友参考一下.

php等比例生成缩略图程序代码如下:

1. function reSizeImg($imgSrc, $resize_width, $resize_height, $isCut=false) {
2. //图片的类型
3. $type = substr ( strrchr ( $imgSrc, "." ), 1 );
4. //初始化图象
5. if ($type == "jpg") {
6. $im = imagecreatefromjpeg ( $imgSrc );
7. }
8. if ($type == "gif") {
9. $im = imagecreatefromgif ( $imgSrc );
10. }
11. if ($type == "png") {
12. $im = imagecreatefrompng ( $imgSrc );
13. }
14. //目标图象地址
15. $full_length = strlen ( $imgSrc );
16. $type_length = strlen ( $type );
17. $name_length = $full_length - $type_length;
18. $name = substr ( $imgSrc, 0, $name_length - 1 );
19. $dstimg = $name . "_s." . $type;
20. $width = imagesx ( $im );
21. $height = imagesy ( $im );
22. //生成图象
23. //改变后的图象的比例
24. $resize_ratio = ($resize_width) / ($resize_height);
25. //实际图象的比例
26. $ratio = ($width) / ($height);
27. if (($isCut) == 1) //裁图
28. {
29. if ($ratio >= $resize_ratio) //高度优先
30. {
31. $newimg = imagecreatetruecolor ( $resize_width, $resize_height );
32. imagecopyresampled ( $newimg, $im, 0, 0, 0, 0, $resize_width, $resize_height, (($height) * $resize_ratio), $height );
33. ImageJpeg ( $newimg, $dstimg );
34. }
35. if ($ratio < $resize_ratio) //宽度优先
36. {
37. $newimg = imagecreatetruecolor ( $resize_width, $resize_height );
38. imagecopyresampled ( $newimg, $im, 0, 0, 0, 0, $resize_width, $resize_height, $width, (($width) / $resize_ratio) );
39. ImageJpeg ( $newimg, $dstimg );
40. }
41. } else //不裁图
42. {//开源代码phpfensi.com
43. if ($ratio >= $resize_ratio) {
44. $newimg = imagecreatetruecolor ( $resize_width, ($resize_width) / $ratio );
45. imagecopyresampled ( $newimg, $im, 0, 0, 0, 0, $resize_width, ($resize_width) / $ratio, $width, $height );
46. ImageJpeg ( $newimg, $dstimg );
47. }
48. if ($ratio < $resize_ratio) {
49. $newimg = imagecreatetruecolor ( ($resize_height) * $ratio, $resize_height );
50. imagecopyresampled ( $newimg, $im, 0, 0, 0, 0, ($resize_height) * $ratio, $resize_height, $width, $height );
51. ImageJpeg ( $newimg, $dstimg );
52. }
53. }
54. ImageDestroy ( $im );
55. }

调用方法简单,直接reSizeImg就可以了,参考很简单.