[KevinH]

The Reports are actually generated from a snapshot of an epub at one particular time. Deleting involves two changes: removing the file and updating the opf manifest. Renaming an image involves updating the opf manifest then searching the entire set of svg, css, and xhtml files to update any links to that image accordingly. This coupled with the need to rerun all reports at the same time, would be a horribly slow process.

If what you really want is a way to set the alt or title of an image based on its thumbnail (for later processing with a regex) where you can see all thumbnails at once, you would be much better off with a plugin. My AccessAide plugin already has the ability to show thumbnails of every image and allows the user to easily edit the alt attribute assigned to that image.

It could easily be extracted into its own plugin and modified to instead add a title attribute to a parent heading tag or any other image related change based on thumbnails - without requiring image file renaming (and the associated search to update any links to it) nor the constant rebuilding of Reports.

So I think a plugin would be best here. Please try running my Access-Aide plugin and look at the alt renaming gui interface and see if something along those lines might be made to do what you need if split out into its own plugin.