This package adds a "Resize Images..." menu item to the context menu of all images. This opens a dialog where you set the desired image size and file name. A click on "Resize" finally resizes the image(s) using ImageMagick's convert tool.
It does work in Mint, but not in nemo - it is a nautilus plug in. Would be good to have in nemo, but if you need to use it in mint then just open up nautilus.