G'MIC

G'MIC is a graphics editing tool created for advanced users who don’t necessarily need to rely on a graphic user interface to manipulate images. It’s a command line application that uses specific commands in order to apply any kind of modification to a photo.

A Command Prompt image editor that’s almost easy to use

As previously mentioned, G'MIC doesn’t display a graphic user interface and to be able to use it you need to have at least basic knowledge of how applications work using Command Prompt.
There isn’t a specific set of default or universal commands that you need to learn by heart as the application supplies you with lists which contain all of them. Along with the actual command form, G'MIC also displays a short explanation for it. It's worth mentioning that the documentation which is distributed with the app is more than enough to help you understand how everything works or how it can be made to work.
In a few words, the entire process comes down to writing the commands which tell G'MIC which file to open, what effect to apply, its value, as well as what new name to give the output file. It’s actually fairly simple and it gets easier as you familiarize yourself with the workflow.

Work with any type of image format, including RAW

G'MIC is an image processing framework that is designed to handle generic 1D, 2D and 3D multi-spectral image datasets. In plain terms it can be used to manipulate anything, JPEG, RAW, you name it. Each file you load is disassembled into its corresponding number of dimensions, width, height, depth, spectrum and worked on using the commands you assign.

Edit images using processing pipelines

The above only scratches the surface of what G'MICcan do. Being and open-source interpreter for the programming language with the same name, it's a very capable tool when it comes to image processing but it does require a decent amount of know-how to be able to use it at its full potential.