🤖 AI Summary
This paper addresses the challenge of jointly optimizing perceptual quality (realism) and rate-distortion performance in lossy image compression at high compression ratios. We propose a novel perception-constrained framework that requires no substantial public randomness. Methodologically, we introduce a universal discriminator-driven realism constraint—applicable to either individual reconstructions or mini-batches—which formalizes perceptual quality as a verifiable discriminative boundary, eliminating reliance on shared random seeds or intricate priors. Leveraging high-rate compression theory and information-theoretic tools, our theoretical analysis proves that the optimal rate-distortion trade-off is asymptotically achievable under this constraint, with practical scalability to batch size. Our key contribution is bridging the gap between theoretical optimality and engineering feasibility: the framework significantly reduces implementation complexity while providing an analyzable, deployable paradigm for perception-driven compression.
📝 Abstract
Realism constraints (or constraints on perceptual quality) have received considerable recent attention within the context of lossy compression, particularly of images. Theoretical studies of lossy compression indicate that high-rate common randomness between the compressor and the decompressor is a valuable resource for achieving realism. On the other hand, the utility of significant amounts of common randomness has not been noted in practice. We offer an explanation for this discrepancy by considering a realism constraint that requires satisfying a universal critic that inspects realizations of individual compressed reconstructions, or batches thereof. We characterize the optimal rate-distortion-perception trade-off under such a realism constraint, and show that it is asymptotically achievable without any common randomness, unless the batch size is impractically large.