How to control the generated image to use only lower case letters when inserting user account

[Migrated From Jforum.net]

I find the generated image usually showing ambiguious letters when the user try to register a new account. The color of the image background might be too close to the color of the shown letters or digits.

I usually need to try 3 times to enter the shown challenge code correctly when I register a new user account.

How can I slightly modify the code so that it only use lower case letters and use the black background.

Could anyone point me to the source code?

Many thanks in advance!
Michael Wu
[originally posted on jforum.net by michaelwu]

[Migrated From Jforum.net]

Hi,

In the development source (2.1.7-dev) a new parameter called captcha.ignore.case = false is introduced. You do not find that in 2.1.6 I think.
There are no way in this configuration to select what "style" that are used. That would be a good idea to introduce something like that.

JForum uses the JCaptcha package for this (http://jcaptcha.sourceforge.net/).

You can modify net/jforum/util/Captcha.java in order to achieve what you want.

But, please file an issue into Jira asking for more general changes to this class. There are probably others that would like to be able to change this without having to recompile the code.

Best regards,

Jakob
[originally posted on jforum.net by lazee]