1,303 research outputs found
Physics-guided Noise Neural Proxy for Low-light Raw Image Denoising
Low-light raw image denoising plays a crucial role in mobile photography, and
learning-based methods have become the mainstream approach. Training the
learning-based methods with synthetic data emerges as an efficient and
practical alternative to paired real data. However, the quality of synthetic
data is inherently limited by the low accuracy of the noise model, which
decreases the performance of low-light raw image denoising. In this paper, we
develop a novel framework for accurate noise modeling that learns a
physics-guided noise neural proxy (PNNP) from dark frames. PNNP integrates
three efficient techniques: physics-guided noise decoupling (PND),
physics-guided proxy model (PPM), and differentiable distribution-oriented loss
(DDL). The PND decouples the dark frame into different components and handles
different levels of noise in a flexible manner, which reduces the complexity of
the noise neural proxy. The PPM incorporates physical priors to effectively
constrain the generated noise, which promotes the accuracy of the noise neural
proxy. The DDL provides explicit and reliable supervision for noise modeling,
which promotes the precision of the noise neural proxy. Extensive experiments
on public low-light raw image denoising datasets and real low-light imaging
scenarios demonstrate the superior performance of our PNNP framework
Generative Prior for Unsupervised Image Restoration
The challenge of restoring real world low-quality images is due to a lack of appropriate training data and difficulty in determining how the image was degraded. Recently, generative models have demonstrated great potential for creating high- quality images by utilizing the rich and diverse information contained within the model’s trained weights and learned latent representations. One popular type of generative model is the generative adversarial network (GAN). Many new methods have been developed to harness the information found in GANs for image manipulation. Our proposed approach is to utilize generative models for both understanding the degradation of an image and restoring it. We propose using a combination of cycle consistency losses and self-attention to enhance face images by first learning the degradation and then using this information to train a style-based neural network. We also aim to use the latent representation to achieve a high level of magnification for face images (x64). By incorporating the weights of a pre-trained StyleGAN into a restoration network with a vision transformer layer, we hope to improve the current state-of-the-art in face image restoration. Finally, we present a projection-based image-denoising algorithm named Noise2Code in the latent space of the VQGAN model with a fixed-point regularization strategy. The fixed-point condition follows the observation that the pre-trained VQGAN affects the clean and noisy images in a drastically different way. Unlike previous projection-based image restoration in the latent space, both the denoising network and VQGAN model parameters are jointly trained, although the latter is not needed during the testing. We report experimental results to demonstrate that the proposed Noise2Code approach is conceptually simple, computationally efficient, and generalizable to real-world degradation scenarios
LIRA: Lifelong Image Restoration from Unknown Blended Distortions
Most existing image restoration networks are designed in a disposable way and
catastrophically forget previously learned distortions when trained on a new
distortion removal task. To alleviate this problem, we raise the novel lifelong
image restoration problem for blended distortions. We first design a base
fork-join model in which multiple pre-trained expert models specializing in
individual distortion removal task work cooperatively and adaptively to handle
blended distortions. When the input is degraded by a new distortion, inspired
by adult neurogenesis in human memory system, we develop a neural growing
strategy where the previously trained model can incorporate a new expert branch
and continually accumulate new knowledge without interfering with learned
knowledge. Experimental results show that the proposed approach can not only
achieve state-of-the-art performance on blended distortions removal tasks in
both PSNR/SSIM metrics, but also maintain old expertise while learning new
restoration tasks.Comment: ECCV2020 accepte
Neural Image Restoration for Images with Diverse Distortion Factors
Tohoku University岡谷貴之課
ニューラルネットワークによる多様な劣化要因を持つ画像の画像復元
Tohoku University博士(情報科学)博士学位論文 (Thesis(doctor))doctoral thesi
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