How to extract all "put in cell" images from google spreadsheet in high resolution

I have a google spreadsheet with imported (Insert>Image>In cell) photos, which I would like to extract (save to disk) in their full resolution, i.e. how they show if I do right click>Image>Put image over cells. Saving as web page etc only grabs images in their low-res form (how they show "in cell"). Can you please help me with a script, or something? Thanks!