Gabor is Enough: Interpretable Deep Denoising with a Gabor Synthesis Dictionary Prior

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Janjušević, Nikola, Khalilian-Gourtani, Amirhossein, Wang, Yao
Format: Preprint
Published: 2022
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917080374181888
author Janjušević, Nikola
Khalilian-Gourtani, Amirhossein
Wang, Yao
author_facet Janjušević, Nikola
Khalilian-Gourtani, Amirhossein
Wang, Yao
contents Image processing neural networks, natural and artificial, have a long history with orientation-selectivity, often described mathematically as Gabor filters. Gabor-like filters have been observed in the early layers of CNN classifiers and even throughout low-level image processing networks. In this work, we take this observation to the extreme and explicitly constrain the filters of a natural-image denoising CNN to be learned 2D real Gabor filters. Surprisingly, we find that the proposed network (GDLNet) can achieve near state-of-the-art denoising performance amongst popular fully convolutional neural networks, with only a fraction of the learned parameters. We further verify that this parameterization maintains the noise-level generalization (training vs. inference mismatch) characteristics of the base network, and investigate the contribution of individual Gabor filter parameters to the performance of the denoiser. We present positive findings for the interpretation of dictionary learning networks as performing accelerated sparse-coding via the importance of untied learned scale parameters between network layers. Our network's success suggests that representations used by low-level image processing CNNs can be as simple and interpretable as Gabor filterbanks.
format Preprint
id arxiv_https___arxiv_org_abs_2204_11146
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Gabor is Enough: Interpretable Deep Denoising with a Gabor Synthesis Dictionary Prior
Janjušević, Nikola
Khalilian-Gourtani, Amirhossein
Wang, Yao
Image and Video Processing
Computer Vision and Pattern Recognition
Signal Processing
Image processing neural networks, natural and artificial, have a long history with orientation-selectivity, often described mathematically as Gabor filters. Gabor-like filters have been observed in the early layers of CNN classifiers and even throughout low-level image processing networks. In this work, we take this observation to the extreme and explicitly constrain the filters of a natural-image denoising CNN to be learned 2D real Gabor filters. Surprisingly, we find that the proposed network (GDLNet) can achieve near state-of-the-art denoising performance amongst popular fully convolutional neural networks, with only a fraction of the learned parameters. We further verify that this parameterization maintains the noise-level generalization (training vs. inference mismatch) characteristics of the base network, and investigate the contribution of individual Gabor filter parameters to the performance of the denoiser. We present positive findings for the interpretation of dictionary learning networks as performing accelerated sparse-coding via the importance of untied learned scale parameters between network layers. Our network's success suggests that representations used by low-level image processing CNNs can be as simple and interpretable as Gabor filterbanks.
title Gabor is Enough: Interpretable Deep Denoising with a Gabor Synthesis Dictionary Prior
topic Image and Video Processing
Computer Vision and Pattern Recognition
Signal Processing
url https://arxiv.org/abs/2204.11146