This is a very basic FAQ about CAPTCHA. For more info please read
docs/CAPTCHA.txt from 4images package.
| Q: | What is CAPTCHA? |
| A: | A CAPTCHA (an acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart") is a type of challenge-response test used in computing to determine whether or not the user is human. (you can find more info about it here) |
| Q: | Where CAPTCHA being used in 4images? |
| A: | By default the following forms can be protected by CAPTCHA:
- Registration
- E-Cards
- Comments
- Image-Upload
|
| Q: | How do I enable/disable CAPTCHA or how do I control it? |
| A: | You can control the CAPTCHA system in your config.php by inserting the following configuration variables above closing
- $captcha_enable = 1;
A value of 1 enables the CAPTCHA system, 0 disables it.
Default value is 1.
- $captcha_enable_comments = 1;
A value of 1 enables the CAPTCHA system for the comments
form, 0 disables it.
Default value is 1.
- $captcha_enable_upload = 1;
A value of 1 enables the CAPTCHA system for the upload
form, 0 disables it.
Default value is 1.
- $captcha_enable_registration = 1;
A value of 1 enables the CAPTCHA system for the
registration form, 0 disables it.
Default value is 1.
- $captcha_enable_postcards = 1;
A value of 1 enables the CAPTCHA system for the e-cards
form, 0 disables it.
Default value is 1.
- $captcha_path = './captcha';
Path to the folder which contains the CAPTCHA files
(backgrounds, fonts).
- $captcha_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
A list of letters which will be used for the
randomly generated CAPTCHA strings
Default value is "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ".
- $captcha_length = 5;
Number of letters of the CAPTCHA strings
Default value is 5.
- $captcha_wordfile = 0;
If this option is set to 1, a word from
"captcha/wordlist.txt" is used.
Default value is 0.
- $captcha_width = 200;
Width of the CAPTCHA image in pixel.
Default value is 200.
- $captcha_height = 70;
Height of the CAPTCHA image in pixel.
Default value is 70.
- $captcha_text_color = "#000000";
Color (Hex) of the CAPTCHA text.
Default value is "#000000" (black).
- $captcha_text_size = 25;
Size of the CAPTCHA text.
Default value is 25.
- $captcha_text_transparency = 60;
Transparency of the CAPTCHA text.
Default value is 60.
- $captcha_filter_text = 1;
If this option is set to 1, the CAPTCHA text will
be filtered ("obscured").
Default value is 1.
- $captcha_filter_bg = 1;
If this option is set to 1, the CAPTCHA background
image will be filtered ("obscured").
Default value is 1.
|
| Q: | Why I cannot see CAPTCHA image? |
| A: | There are several possible reasons:
- CAPTCHA is disabled. Look previous question for more info.
- You are using an old/custom template that does not support CAPTCHA. You can find detailed template changes here
- Your server does not support GD library. If you look in phpinfo() and can't find anything about GD, then most probably its not installed/enabled on your server. In that case contact your host's administrator. Until they enable/install GD you won't have other choice but disable CAPTCHA feature (see above)
- Some FTP programms gernerate a log file after uploading files to a server. Make sure that in the directory /captacha/backgrounds/ on your server are ONLY the background images for the CAPTCHA and not any other files like wsftp.log, thumbs.db, etc.
- You are logged in as admin. Administrators don't have to enter verifications codes
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