295 research outputs found
Wavelet domain style transfer for an effective perception-distortion tradeoff in single image super-resolution
In single image super-resolution (SISR), given a low-resolution (LR) image, one wishes to find a high-resolution (HR) version of it which is both accurate and photorealistic. Recently, it has been shown that there exists a fundamental tradeoff between low distortion and high perceptual quality, and the generative adversarial network (GAN) is demonstrated to approach the perception-distortion (PD) bound effectively. In this paper, we propose a novel method based on wavelet domain style transfer (WDST), which achieves a better PD tradeoff than the GAN based methods. Specifically, we propose to use 2D stationary wavelet transform (SWT) to decompose one image into low-frequency and high-frequency sub-bands. For the low-frequency sub-band, we improve its objective quality through an enhancement network. For the high-frequency sub-band, we propose to use WDST to effectively improve its perceptual quality. By feat of the perfect reconstruction property of wavelets, these sub-bands can be re-combined to obtain an image which has simultaneously high objective and perceptual quality. The numerical results on various datasets show that our method achieves the best trade-off between the distortion and perceptual quality among the existing state-of-the-art SISR methods
PyNET-CA: Enhanced PyNET with Channel Attention for End-to-End Mobile Image Signal Processing
Reconstructing RGB image from RAW data obtained with a mobile device is
related to a number of image signal processing (ISP) tasks, such as
demosaicing, denoising, etc. Deep neural networks have shown promising results
over hand-crafted ISP algorithms on solving these tasks separately, or even
replacing the whole reconstruction process with one model. Here, we propose
PyNET-CA, an end-to-end mobile ISP deep learning algorithm for RAW to RGB
reconstruction. The model enhances PyNET, a recently proposed state-of-the-art
model for mobile ISP, and improve its performance with channel attention and
subpixel reconstruction module. We demonstrate the performance of the proposed
method with comparative experiments and results from the AIM 2020 learned
smartphone ISP challenge. The source code of our implementation is available at
https://github.com/egyptdj/skyb-aim2020-publicComment: ECCV 2020 AIM workshop accepted versio
A Comprehensive Review of Deep Learning-based Single Image Super-resolution
Image super-resolution (SR) is one of the vital image processing methods that
improve the resolution of an image in the field of computer vision. In the last
two decades, significant progress has been made in the field of
super-resolution, especially by utilizing deep learning methods. This survey is
an effort to provide a detailed survey of recent progress in single-image
super-resolution in the perspective of deep learning while also informing about
the initial classical methods used for image super-resolution. The survey
classifies the image SR methods into four categories, i.e., classical methods,
supervised learning-based methods, unsupervised learning-based methods, and
domain-specific SR methods. We also introduce the problem of SR to provide
intuition about image quality metrics, available reference datasets, and SR
challenges. Deep learning-based approaches of SR are evaluated using a
reference dataset. Some of the reviewed state-of-the-art image SR methods
include the enhanced deep SR network (EDSR), cycle-in-cycle GAN (CinCGAN),
multiscale residual network (MSRN), meta residual dense network (Meta-RDN),
recurrent back-projection network (RBPN), second-order attention network (SAN),
SR feedback network (SRFBN) and the wavelet-based residual attention network
(WRAN). Finally, this survey is concluded with future directions and trends in
SR and open problems in SR to be addressed by the researchers.Comment: 56 Pages, 11 Figures, 5 Table
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