Generate thumbnails in the php GD library

Php GD library
Php uses the GD library to generate thumbnails.
Code:

1. <Form method = "post" action = "suo_do.php" enctype = "multipart/form-data">
2. <Input type = "file" name = "pic"/>
3. <Input type = "submit" value = "Upload 1"/>
4. </Form>
5. <? Php
6. Header ("content-type: text/html; charset = gbk ");
7. Ini_set ("date. timezone", "Asia/chong ");
8. // Determine whether the file is empty
9. If (empty ($ _ FILES )){
10. Echo "uploading files too large ";
11. Exit;
12. }
13. // Determine whether the file is uploaded incorrectly
14. If ($ _ FILES ['pic '] ['error']) {
15. Echo "upload files ";
16. Exit;
17. }
18. // Determine whether the file type is illegal to obtain the file suffix
19. $ Allowtype = array ("jpg", "png", "jpeg", "gif ");
20. $ A = explode ('.', $ _ FILES ['pic '] ['name']);
21. $ Index = count ($ a)-1;
22. $ Ex = strtolower ($ a [$ index]);
23. If (! In_array ($ ex, $ allowtype )){
24. Echo "Illegal File Upload ";
25. Exit;
26. }
27. $ File = date ('ymdhis '). rand (). ".". $ ex;
28. $ Src = $ _ FILES ['pic '] ['tmp _ name'];
29. $ Des = "upload/". $ file;
30. $ Rs = move_uploaded_file ($ src, $ des );
32. // Thumbnail
33. // Read the uploaded Image
34. $ Image = imagecreatefromjpeg ($ des );
35. $ A = getimagesize ($ des );
36. $ W = $ a [0];
37. $ H = $ a [1];
38. If ($ w> $ h ){
39. $ Width = 300;
40. $ Height = $ width/$ w * $ h;
41. } Else if ($ w <$ h ){
42. $ Height = 300;
43. $ Width = $ height/$ h * $ w;
44. } Else {
45. $ Width = 300;
46. $ Height = 300;
47. } Www.jbxue.com
48. // Create a blank image
49. $ Newimage = imagecreatetruecolor ($ width, $ height );
50. // Copy source image content copy New Image
51. Imagecopyresized ($ newimage, $ image, 0, 0, 0, $ width, $ height, $ w, $ h );
52. $ Filename = "upload/s _". $ file;
53. Imagejpeg ($ newimage, $ filename );