Reply To: How access both InDesign and Photoshop in one script?

I wrote a number of such scripts. A few of them you can find on my site. For example, Resize images for Power Switch and Resize images.

– can I call a Photoshop action from the InDesign script?

Yes, you can. Here's an example. It displays available in Photoshop sets and the actions for each set in the dialog box and calls the selected action in line #205:

if (eval(myRunAction) == true) app.doAction(myAction, mySet);

Hope this helps.
Kasyan