Small regex javascript code

General information for the website: Code tweak
Description of every page/module: Single edit to one line of JavaScript
Description of requirements/features: I need to tweak a function in my installation of TinyMCE. TinyMCE allows us to list groups of styles.
For example, the following would display a list of classes applied to DIVs or Ps.

{title: 'Block styles', filter: /^(div|p)\./}

I'd like to display a list of classes which:
- contain the word 'image' eg .imageleft
- contain the word 'img' eg.imgleft
- or are prefix by the tag img eg. img.leftborder

But I can't figure out the regex to do it :(
Extra notes: