A Revisit to Rate-distortion Theory via Optimal Weak Transport
Jiayang Zou, Luyao Fan, Jiayang Gao, Jia Wang
TL;DR
Within the framework of weak transport problems, a parametric representation of the rate-distortion function is derived, thereby connecting the rate-distortion function with the Schr\"odinger bridge problem, and establishing necessary conditions for its optimality.
Abstract
This paper revisits the rate-distortion theory from the perspective of optimal weak transport, as recently introduced by Gozlan et al. While the conditions for optimality and the existence of solutions are well-understood in the case of discrete alphabets, the extension to abstract alphabets requires more intricate analysis. Within the framework of weak transport problems, we derive a parametric representation of the rate-distortion function, thereby connecting the rate-distortion function with the Schrödinger bridge problem, and establish necessary conditions for its optimality. As a byproduct of our analysis, we reproduce K. Rose's conclusions regarding the achievability of Shannon lower bound concisely, without reliance on variational calculus.
