Title
DCT2net: An Interpretable Shallow CNN for Image Denoising
Abstract
This work tackles the issue of noise removal from images, focusing on the well-known DCT image denoising algorithm. The latter, stemming from signal processing, has been well studied over the years. Though very simple, it is still used in crucial parts of state-of-the-art "traditional" denoising algorithms such as BM3D. For a few years however, deep convolutional neural networks (CNN), especially DnCNN, have outperformed their traditional counterparts, making signal processing methods less attractive. In this paper, we demonstrate that a DCT denoiser can be seen as a shallow CNN and thereby its original linear transform can be tuned through gradient descent in a supervised manner, improving considerably its performance. This gives birth to a fully interpretable CNN called DCT2net. To deal with remaining artifacts induced by DCT2net, an original hybrid solution between DCT and DCT2net is proposed combining the best that these two methods can offer; DCT2net is selected to process non-stationary image patches while DCT is optimal for piecewise smooth patches. Experiments on artificially noisy images demonstrate that two-layer DCT2net provides comparable results to BM3D and is as fast as DnCNN algorithm.
Year
DOI
Venue
2022
10.1109/TIP.2022.3181488
IEEE TRANSACTIONS ON IMAGE PROCESSING
Keywords
DocType
Volume
Discrete cosine transforms, Noise reduction, Convolutional neural networks, Transforms, Kernel, Convolution, Signal processing algorithms, Convolutional neural network, image denoising, Canny edge detector, artifact removal
Journal
31
Issue
ISSN
Citations 
1
1057-7149
0
PageRank 
References 
Authors
0.34
0
2
Name
Order
Citations
PageRank
Sebastien Herbreteau100.34
Charles Kervrann293467.36