110 research outputs found
Single-Image Deraining via Recurrent Residual Multiscale Networks.
Existing deraining approaches represent rain streaks with different rain layers and then separate the layers from the background image. However, because of the complexity of real-world rain, such as various densities, shapes, and directions of rain streaks, it is very difficult to decompose a rain image into clean background and rain layers. In this article, we develop a novel single-image deraining method based on residual multiscale pyramid to mitigate the difficulty of rain image decomposition. To be specific, we progressively remove rain streaks in a coarse-to-fine fashion, where heavy rain is first removed in coarse-resolution levels and then light rain is eliminated in fine-resolution levels. Furthermore, based on the observation that residuals between a restored image and its corresponding rain image give critical clues of rain streaks, we regard the residuals as an attention map to remove rains in the consecutive finer level image. To achieve a powerful yet compact deraining framework, we construct our network by recurrent layers and remove rain with the same network in different pyramid levels. In addition, we design a multiscale kernel selection network (MSKSN) to facilitate our single network to remove rain streaks at different levels. In this manner, we reduce 81% of the model parameters without decreasing deraining performance compared with our prior work. Extensive experimental results on widely used benchmarks show that our approach achieves superior deraining performance compared with the state of the art
RainDiffusion:When Unsupervised Learning Meets Diffusion Models for Real-world Image Deraining
What will happen when unsupervised learning meets diffusion models for
real-world image deraining? To answer it, we propose RainDiffusion, the first
unsupervised image deraining paradigm based on diffusion models. Beyond the
traditional unsupervised wisdom of image deraining, RainDiffusion introduces
stable training of unpaired real-world data instead of weakly adversarial
training. RainDiffusion consists of two cooperative branches: Non-diffusive
Translation Branch (NTB) and Diffusive Translation Branch (DTB). NTB exploits a
cycle-consistent architecture to bypass the difficulty in unpaired training of
standard diffusion models by generating initial clean/rainy image pairs. DTB
leverages two conditional diffusion modules to progressively refine the desired
output with initial image pairs and diffusive generative prior, to obtain a
better generalization ability of deraining and rain generation. Rain-Diffusion
is a non adversarial training paradigm, serving as a new standard bar for
real-world image deraining. Extensive experiments confirm the superiority of
our RainDiffusion over un/semi-supervised methods and show its competitive
advantages over fully-supervised ones.Comment: 9 page
Restoring Vision in Hazy Weather with Hierarchical Contrastive Learning
Image restoration under hazy weather condition, which is called single image
dehazing, has been of significant interest for various computer vision
applications. In recent years, deep learning-based methods have achieved
success. However, existing image dehazing methods typically neglect the
hierarchy of features in the neural network and fail to exploit their
relationships fully. To this end, we propose an effective image dehazing method
named Hierarchical Contrastive Dehazing (HCD), which is based on feature fusion
and contrastive learning strategies. HCD consists of a hierarchical dehazing
network (HDN) and a novel hierarchical contrastive loss (HCL). Specifically,
the core design in the HDN is a hierarchical interaction module, which utilizes
multi-scale activation to revise the feature responses hierarchically. To
cooperate with the training of HDN, we propose HCL which performs contrastive
learning on hierarchically paired exemplars, facilitating haze removal.
Extensive experiments on public datasets, RESIDE, HazeRD, and DENSE-HAZE,
demonstrate that HCD quantitatively outperforms the state-of-the-art methods in
terms of PSNR, SSIM and achieves better visual quality.Comment: 30 pages, 10 figure
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