Shape approximation through recursive scalable layer generation

Abstract

This paper presents an efficient recursive algorithm for generating operationally optimal intra mode scalable layer decompositions of object contours. The problem is posed in terms of minimizing the shape distortion at full reconstruction subject to the total (for all scalable layers) bit budget constraint. Based on the chosen vertex-based representation, we solve the problem of determining the number and locations of approximating vertices for all scalable layers jointly and optimally. The number of scalable layers is not constrained, but, rather, is a by-product of the proposed optimization. The algorithm employs two different coding strategies: one for the base layer and one for the enhancement layers. By carefully defining scalable layer recursion and base layer segment costs the problem is solved by executing a directed acyclic graph (DAG) shortest path algorithm.