Programming at the End of the Learning Curve: Lisp Scripting for Image Processing Steven L. Tanimoto and Jeremy W. Baer University of Washington Symposium on End User Programming Human-Centric Computing Languages and Environments Stresa, Italy September 5-7, 2001

Tanimoto and Baer HCC Mathematics Experiences Through Image Processing Project to engage middle-school and high- school students. Exploits visual and mathematical structure of digital images. Permits students to work with “personal” materials.

Tanimoto and Baer HCC Software Developed Pixel Calculator (monochrome) Color Pixel Calculator Image Warper Color XFORM (both PC and Mac versions) Visual/mathematical interface Image processing engine Programming environment

Tanimoto and Baer HCC Needs for Scripting Easy configure the image processing environment for particular student activities. Teach programming in the context of image processing.

Tanimoto and Baer HCC Criteria for Choice of Language Interpreted Standard and usable in other contexts Documentation readily available Simple syntax Easy to integrate with image processing (Lisp meets these criteria).

Tanimoto and Baer HCC 20016

7 Learning Curve Learners use direct manipulation prior to programming gaining familiarity with operations. They develop motivation to automate certain tasks. Programming satisfies their need. The language has depth, and they can go as far into it as they desire.

Tanimoto and Baer HCC Issues How best to teach programming abstractions in an image processing context. (conditionals, loops, recursion, data types) Possible enhancements to the programming environment: customized debugging affordances, templates for standard image transformations, etc. A possible visual scripting language.