[Plugin: WP Catalogue} Specify a banner image, if a page has a plugin

I’ve added the WP Catalogue plugin to my WordPress site and it’s working smoothly.

Only issue is that I want to have a different banner image on each of the pages that are generated by WP Catalogue. All pages with WP Catalogue would have the same image.

Currently, for other pages, the banner image is specified in a header.php file, like this:

elseif (is_page(‘[page id number]’) )
{
echo “<img src='[image source]’ />”;
}

Since I’ll be adding a bunch of entries to the WP Catalogue, I don’t want to have to go in and update the header.php file with another image source statement, each time.

The best way I can think to do this is to tell WordPress “If a page has the WP Catalogue plugin present, use this image.” But I’m not sure what that PHP statement would look like. Any help?