1. <?php
2. $consts = 'bcdfghjkmnpqrstwxyz';
3. $vowels = 'aei23456789';
4. for ($x = 0; $x < 6; $x++)
5. {
6. $const[$x] = substr($consts, mt_rand(0,strlen($consts)-1),1);
7. $vow[$x] = substr($vowels, mt_rand(0,strlen($vowels)-1),1);
8. }
9. $radomstring = $const[0] . $vow[0] .$const[2] . $const[1] . $vow[1] . $const[3] . $vow[3] . $const[4];
10. $_SESSION['checkcode'] = $string = substr($radomstring,0,4); //only display 4 str
11. / t up image, the first number is the width and the second is the height
12. $imageX = strlen($radomstring)*5.5; //the image width
13. $imageY = 20; //the image height
14. $im = imagecreatetruecolor($imageX,$imageY);
15. //creates two variables to store color
16. $background = imagecolorallocate($im, rand(180, 250), rand(180, 250), rand(180, 250));
17. $foregroundArr = array(imagecolorallocate($im, rand(0, 20), rand(0, 20), rand(0, 20)),
18. imagecolorallocate($im, rand(0, 20), rand(0, 10), rand(245, 255)),
19. imagecolorallocate($im, rand(245, 255), rand(0, 20), rand(0, 10)),
20. imagecolorallocate($im, rand(245, 255), rand(0, 20), rand(245, 255)));
21. $foreground2 = imagecolorallocatealpha($im, rand(20, 100), rand(20, 100), rand(20, 100),80);
22. $middleground = imagecolorallocate($im, rand(200, 160), rand(200, 160), rand(200, 160));
23. $middleground2 = imagecolorallocatealpha($im, rand(180, 140), rand(180, 140), rand(180, 140),80);
24. //fill image with bgcolor
25. imagefill($im, 0, 0, imagecolorallocate($im, 250, 253, 254));
26. //writes string
27. imagestring($im, 5, 3, floor(rand(0,5))-1, $string[0], $foregroundArr[rand(0,3)]);
28. imagestring($im, 5, 13, floor(rand(0,5))-1, $string[1], $foregroundArr[rand(0,3)]);
29. imagestring($im, 5, 23, floor(rand(0,5))-1, $string[2], $foregroundArr[rand(0,3)]);
30. imagestring($im, 5, 33, floor(rand(0,5))-1, $string[3], $foregroundArr[rand(0,3)]);
31. for($i=0; $i<strlen($string); $i++)
32. {
33. if(mt_rand(0,ord(substr($string,$i,1)))%2 == 0)
34. {
35. $string{$i} = ' ';
36. }
37. }
38. imagestring($im, 2, 2, 0, $string, $foreground2);
39. //strikethrough
40. $border = imagecolorallocate($im, 133, 153, 193);
41. //imagefilledrectangle($aimg, 0, 0, $x_size - 1, $y_size - 1, $back);
42. imagerectangle($im, 0, 0, $imageX - 1, $imageY - 1, $border);
43. $pointcol = imagecolorallocate($im, rand(0,255), rand(0,255), rand(0,255));
44. for ($i=0;$i<20;$i++)
45. {
46. imagesetpixel($im,rand(2,$imageX-2),rand(2,$imageX-2),$pointcol);
47. }
48. //rotate
49. $middleground = imagecolorallocatealpha($im, rand(160, 200), rand(160, 200), rand(160, 200), 80);
50. //random shapes
51. for ($x=0; $x<15;$x++)
52. {
53. if(mt_rand(0,$x)%2==0)
54. {
55. imageline($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), $middleground);
56. imageellipse($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), $middleground2);
57. }
58. else
59. {
60. imageline($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), $middleground2);
61. imageellipse($im, rand(0, 120), rand(0, 120), rand(0, 120), rand(0, 120), $middleground);
62. }
63. }//开源代码phpfensi.com
64. //output to browser
65. header("content-type:image/png\r\n");
66. imagepng($im);
67. imagedestroy($im);
68. ?>