Phatch – batch image processor (photos) for Linux. Is intended for mass processing of images. Supports a large number of actions for modifying images.
Allows you to resize, brightness/contrast, color balance. You can add the watermarkto images, batch rename image files, add a drop shadow, round corners and stuff.
The program interface is quite simple and easy to understand.
The program Phatch cross-platform and is available for Linux, Windows and MacOS.
In Linux Mint can be set through the software Center.