Image viewer -> erase selection

Since the image viewer can also double down as a basic image editor (crop selection, rotate/flip, convert), could there also be a way to support erase selection (essentially, a reverse crop)? Or, an alternative pragmatic solution could be to overlay the selection with an all white or all black watermark.

I have seen software that can overlay a watermark via command line (such as ImBatch), but position and size has to be manually user-defined. But doing this via selection rectangle or the re-select option would be ideal.

Wouldn't it be much more flexible and scriptable if there were a command and/or script method which returns the selected area? You could pass that info to imbatch, imagemagick, etc. to do whatever you want or OCR programs to extract text. "Show VIEWERCMD" has also copy, copyto, restore for further manipulation.

ps: For feature requests you should link your account to your license.