Poster
A Unified Framework for Uniform Signal Recovery in Nonlinear Generative Compressed Sensing
Junren Chen · Jonathan Scarlett · Michael Ng · Zhaoqiang Liu
Great Hall & Hall B1+B2 (level 1) #1403
Abstract:
In generative compressed sensing (GCS), we want to recover a signal from measurements () using a generative prior , where is typically an -Lipschitz continuous generative model and represents the radius- -ball in . Under nonlinear measurements, most prior results are non-uniform, i.e., they hold with high probability for a fixed rather than for all simultaneously. In this paper, we build a unified framework to derive uniform recovery guarantees for nonlinear GCS where the observation model is nonlinear and possibly discontinuous or unknown. Our framework accommodates GCS with 1-bit/uniformly quantized observations and single index model as canonical examples. Specifically, using a single realization of the sensing ensemble and generalized Lasso, all can be recovered up to an -error at most using roughly samples, with omitted logarithmic factors typically being dominated by . Notably, this almost coincides with existing non-uniform guarantees up to logarithmic factors, hence the uniformity costs very little. As part of our technical contributions, we introduce Lipschitz approximation to handle discontinuous observation models. We also develop a concentration inequality that produces tighter bound for product process whose index sets have low metric entropy. Experimental results are presented to corroborate our theory.
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