Linux command line tool NOT part of Imagemagick, Gimp to process scaed borders of a book

I had used an linux command line tool similar to convert to remove borders from a scaed image and set the page pixels to white whilst leaving the text alone.

I've forgotten it's name. There are a lot of pkgs in the debian repo so I'm at a loss and was hoping someone might have used it. It had a technical name as the pkg name but I'm not absolutely sure. It also had a threshold option where you could specify degree of whiteness/blackness.

Can someone list the other linux packages that do a similar task to 'convert'?

(also not imagej)