QCM-SGM+: Improved Quantized Compressed Sensing With Score-Based Generative Models

Fuente: arXiv
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Autores principales: Meng, Xiangming, Kabashima, Yoshiyuki
Formato: Preprint
Publicado: 2023
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author Meng, Xiangming
Kabashima, Yoshiyuki
author_facet Meng, Xiangming
Kabashima, Yoshiyuki
contents In practical compressed sensing (CS), the obtained measurements typically necessitate quantization to a limited number of bits prior to transmission or storage. This nonlinear quantization process poses significant recovery challenges, particularly with extreme coarse quantization such as 1-bit. Recently, an efficient algorithm called QCS-SGM was proposed for quantized CS (QCS) which utilizes score-based generative models (SGM) as an implicit prior. Due to the adeptness of SGM in capturing the intricate structures of natural signals, QCS-SGM substantially outperforms previous QCS methods. However, QCS-SGM is constrained to (approximately) row-orthogonal sensing matrices as the computation of the likelihood score becomes intractable otherwise. To address this limitation, we introduce an advanced variant of QCS-SGM, termed QCS-SGM+, capable of handling general matrices effectively. The key idea is a Bayesian inference perspective on the likelihood score computation, wherein expectation propagation is employed for its approximate computation. Extensive experiments are conducted, demonstrating the substantial superiority of QCS-SGM+ over QCS-SGM for general sensing matrices beyond mere row-orthogonality.
format Preprint
id arxiv_https___arxiv_org_abs_2302_00919
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle QCM-SGM+: Improved Quantized Compressed Sensing With Score-Based Generative Models
Meng, Xiangming
Kabashima, Yoshiyuki
Signal Processing
Information Theory
Machine Learning
In practical compressed sensing (CS), the obtained measurements typically necessitate quantization to a limited number of bits prior to transmission or storage. This nonlinear quantization process poses significant recovery challenges, particularly with extreme coarse quantization such as 1-bit. Recently, an efficient algorithm called QCS-SGM was proposed for quantized CS (QCS) which utilizes score-based generative models (SGM) as an implicit prior. Due to the adeptness of SGM in capturing the intricate structures of natural signals, QCS-SGM substantially outperforms previous QCS methods. However, QCS-SGM is constrained to (approximately) row-orthogonal sensing matrices as the computation of the likelihood score becomes intractable otherwise. To address this limitation, we introduce an advanced variant of QCS-SGM, termed QCS-SGM+, capable of handling general matrices effectively. The key idea is a Bayesian inference perspective on the likelihood score computation, wherein expectation propagation is employed for its approximate computation. Extensive experiments are conducted, demonstrating the substantial superiority of QCS-SGM+ over QCS-SGM for general sensing matrices beyond mere row-orthogonality.
title QCM-SGM+: Improved Quantized Compressed Sensing With Score-Based Generative Models
topic Signal Processing
Information Theory
Machine Learning
url https://arxiv.org/abs/2302.00919