High-level dataflow programming for real-time image processing on smart cameras

摘要

We describe the application of the caph programming language to the implementation of complex real-time image processing application on a FPGA embedded in a smart camera architecture. caph is based upon the dataflow model of computation. Applications are described as networks of purely dataflow actors exchanging tokens through unidirectional channels and the behavior of each actor is defined as a set of transition rules using pattern matching. We show that this model is naturally suited to the description of applications operating on the fly on digital video streams and supports a fully automated compilation path producing efficient VHDL code. This is demonstrated on an application performing the extraction of HOG (histogram of oriented gradient) feature vectors in real time on the dreamcam smart camera, an experimental platform developed at our institute.