A simple php Verification Code Program

There are many php verification code programs generated on the Internet. I will share with you the code of a super-Good php verification code. If you need it, please refer to it.

Verification code recognition is generally divided into the following steps:

1. Extract the Model
2. binarization
3. Computing Features
4. comparison sample

The Code is as follows:

Copy code

Function _ code ($ _ code_length = 4, $ _ width = 75, $ _ height = 25 ){ For ($ I = 0; $ I <$ _ code_length; $ I ++ ){ $ _ Nmsg. = dechex (mt_rand (0, 15 )); } $ _ SESSION ["code"] =_ _ nmsg; $ _ Img = imagecreatetruecolor ($ _ width, $ _ height ); $ _ White = imagecolorallocate ($ _ img, 250,250,250 ); Imagefill ($ _ img, 0, 0, $ _ white ); $ _ Gray = imagecolorallocate ($ _ img, 196,196,196 ); Imagerectangle ($ _ img, 0, 0, $ _ width-1, $ _ height-1, $ _ gray ); For ($ I = 0; $ I <6; $ I ++ ){ $ _ Md_color = imagecolorallocate ($ _ img, mt_rand (200,255), mt_rand (200,255), mt_rand (200,255 )); Imageline ($ _ img, mt_rand (0, $ _ width), mt_rand (0, $ _ height), mt_rand (0, $ _ width), mt_rand (0, $ _ height), $ _ md_color ); } For ($ I = 0; $ I <50; $ I ++ ){ $ _ Md_color = imagecolorallocate ($ _ img, mt_rand (200,255), mt_rand (200,255), mt_rand (200,255 )); Imagestring ($ _ img, 1, mt_rand (1, $ _ width-5), mt_rand (1, $ _ height-5), "*", $ _ md_color ); } For ($ I = 0; $ I <$ _ code_length; $ I ++ ){ $ _ Md_color = imagecolorallocate ($ _ img, mt_rand (0,102), mt_rand (0,102), mt_rand (0,102 )); Imagestring ($ _ img, 5, $ I * $ _ width/$ _ code_length + mt_rand (1, 10), mt_rand (1, $ _ height/2 ), $ _ SESSION ["code"] [$ I], $ _ md_color ); } Header ("Content-Type: image/png "); Imagepng ($ _ img ); Imagedestroy ($ _ img ); }

Verification code usage

The Code is as follows:	Copy code
$ Getcode = $ _ POST ['code']; If ($ _ SESSION ["code"] = $ getcode) { Echo 'verify that the verification is valid and proceed to the next '; Unset ($ _ SESSION ["code"]); } Else { Echo 'incorrect Verification Code '; Header ('location: vial. php '); }