want to change headers for category and archive pages

I apologize if this has been asked before but I was unable to find a good answer through searching. I am using the default wordpress theme twentyeleven and I was trying to figure out how I can change my header image banner on the author archive pages and category pages. It doesn’t appear that I can edit those pages directly from the dashboard as they are not static pages, re-populating with each new post. So I realize I may need to change something in the code which I am not opposed to doing but I am new at wordpress and php so as much detailed help as possible would be great.

Specifically I would like the ability to have a unique header for each of the author archive pages located at places such as http://www.mywordpresssite.com/archives/author/individualauthor and each of the category pages located at http://www.mywordpresssite.com/archives.category/individualcategory

I found a plug-in for the twentyten theme (called twentyten Advanced Headers) which allowed you to change the info for the category pages, however it has not yet been updated to twenty eleven. The only other plugin I found the kind of worked was WP Display Header which allowed me to set a header for an individual post and because how wordpress works on the author archive page it shows the header being the header from the last post of that author and the same with the category archive page it shows the header from the last post to use that category tag (regardless of author). That’s all well and good but I was trying to find a way to set the individual author archive page header without having to set it each post and same for the category archive page (especially because I would rather not have problem that comes with WP Display Header Plugin of the category archive page showing the last author’s header that used that category tag instead of a specific category header.)

Hopefully this long post makes sense and any help you can provide would be great.

Thanks,