Dr-Fu: A Crutch for the GIMP

Design Problem: To provide an impvoed scripting interface for the GNU Image Manipulation Program (GIMP), to be used in introductory computer science courses at Grinnell College.

Teammates: Max Kuipers, Tim Miller

Concept: We created a connection between DrScheme, a successful Scheme development environment popular in educational settings and previously used at Grinnell College, and the GIMP's script-fu server, which executes Scheme-based image manipulation scripts. We also made some interface customizations to DrScheme in order to make the experience of writing code in the DrScheme window to be executed by the GIMP as simple and seamless as possible.

Under the supervision of Janet Davis, we researched the needs of novice programmers and performed a heuristic evaluation of the script-fu interface in order to identify the most urgent difficulties to address. Given the major weaknesses of the GIMP's existing interface, and our limited time and resources, we identified a solution that would take advantage of DrScheme's built-in networking capabilities and the GIMP's existing scripting server as the most feasible approach to improving the worst usability problems. We also updated and added to a library of image manipulation functions in order to provide students with a framework that would allow them to begin work on interesting and engaging media computation projects without the need for extensive programming knowledge.

In the final phase of the project, we conducted think-aloud studies with previous CSC-151 students as participants, in order to evaluate our success in solving the original interface problems, and to test for new bugs. The feedback from these studies confirmed that DrScheme provided most of the important usability features the script-fu console lacked, and allowed us to identify and partially resolve a number of usability issues arising from the interaction of DrScheme and the GIMP.