Image Resizer For Ubuntu. Simple image resizer sir is a free tool programmed in c that is designed using qt gui toolkit. Imagemagick can be used to resize images on the command line as well.
It has a minimalistic appearance thus you will not get a lot of options but it has a unique way somewhat of arranging thumbnails of the loaded images after which in my opinion the interface becomes beautiful and fun to work with. Turns out ubuntu has similar abilities if you install the right apps or rather plugins or add ons in this case. If you want to edit tens hundreds or thousands of images i prefer phatch.
It provides support for adding frames or text and apply color and gradient filters to the images.
Imagemagick can be used to resize images on the command line as well. A somewhat hidden but reasonably easy method of scaling and resizing photos and other images within ubuntu linux without downloading or installing any additional graphics editor software. This is used mainly for batch resizing rotating and converting images. I am moving over to ubuntu from windows gradually and have used faststone image resizer for windows for a while and found it very good.