How To Add Your Own Features to GIMP

By Jim on July 22nd, 2010

Here’s something fun for the programmers out there. GIMP is a great application for something like this.

The GNU Image Manipulation Program (GIMP) is a robust application for editing and manipulating digital images. Because it’s open source software, any developer is allowed to modify and extend it with even more features. In this article, you will learn how to get started with the GIMP code, how to build the project from the Git repositories, and how to find your way around the code tree. And you will build an example application that creates a whole new painting tool for the program.

One of the most compelling reasons for using free or open source software is that it provides an opportunity for the user of the product to add whatever features he wants or needs. But the ability to add features is constrained by a project’s size and complexity, and the nature of available documentation. So, while GIMP is one of the most well-known and successful open source software projects, its huge code base can be intimidating.

To follow along, you should be familiar with the C programing language. You should also know or be prepared to learn about the Git versioning tool. The example in this article was created using GIMP V2.7 on a Linux® environment (note that V2.7 is a development branch and not a stable release). The spring 2009 version of Mandriva Linux was used in this article, but any version of Linux should work fine (see Resources).

You will be creating a tool based on an existing painting tool. The tool created in this article is purely for instructional purposes. For it to become an actual project that would be used as part of the GIMP distribution, it would have to be thoroughly vetted by the core GIMP developers and the UI architect.