Prototyping Real-Time Vision Systems: An Experiment in DSL Design


Alastair Reid, John Peterson, Paul Hudak, Greg Hager


We describe the transformation of XVision, a large library of C++ code for real-time vision processing, into FVision (pronounced ``fission''), a fully-featured domain-specific language embedded in Haskell. The resulting prototype system substantiates the claims of increased modularity, effective code reuse, and rapid prototyping that characterize the DSL approach to system design. It also illustrates the need for judicious interface design: relegating computationally expensive tasks to XVision (pre-existing C++ components), and leaving modular compositional tasks to FVision (Haskell). At the same time, our experience demonstrates how Haskell's advanced language features (specifically parametric polymorphism, lazy evaluation, higher order functions and automatic storage reclamation) permit a rapid DSL design that is itself highly modular and easily modified. Overall, the resulting hybrid system exceeded our expectations: visual tracking programs continue to spend most of their time executing low level image-processing code, while Haskell's advanced features allow us to quickly develop and test small prototype systems within a matter of a few days and to develop realistic applications within a few weeks.


Author = "A. Reid and J. Peterson and P. Hudak and G. Hager",  
Title = "Prototyping Real-Time Vision Systems: An Experiment                  
in DSL Design",  
BookTitle = "Proceedings of ICSE 99: Intl. Conf. on Software                  
Month =	 "May",  
Year =	 1999)