NConvert is a very useful command line application that provides support for batch converting graphic files to different formats.
NConvert is able to work with over 400 image files and can export them to over 40 40 graphic file formats.
NOTE: NConvert is FREE only for educational or private non-commercial use (including non-profit organization).
Here are some key features of "Nconvert":
· Allows you to resize the image files.
· You can adjust the contrast, brightness, number of colors and more
· Allows you to apply image effects or filters