679 research outputs found
Recent Progress in Image Deblurring
This paper comprehensively reviews the recent development of image
deblurring, including non-blind/blind, spatially invariant/variant deblurring
techniques. Indeed, these techniques share the same objective of inferring a
latent sharp image from one or several corresponding blurry images, while the
blind deblurring techniques are also required to derive an accurate blur
kernel. Considering the critical role of image restoration in modern imaging
systems to provide high-quality images under complex environments such as
motion, undesirable lighting conditions, and imperfect system components, image
deblurring has attracted growing attention in recent years. From the viewpoint
of how to handle the ill-posedness which is a crucial issue in deblurring
tasks, existing methods can be grouped into five categories: Bayesian inference
framework, variational methods, sparse representation-based methods,
homography-based modeling, and region-based methods. In spite of achieving a
certain level of development, image deblurring, especially the blind case, is
limited in its success by complex application conditions which make the blur
kernel hard to obtain and be spatially variant. We provide a holistic
understanding and deep insight into image deblurring in this review. An
analysis of the empirical evidence for representative methods, practical
issues, as well as a discussion of promising future directions are also
presented.Comment: 53 pages, 17 figure
Convolutional Deblurring for Natural Imaging
In this paper, we propose a novel design of image deblurring in the form of
one-shot convolution filtering that can directly convolve with naturally
blurred images for restoration. The problem of optical blurring is a common
disadvantage to many imaging applications that suffer from optical
imperfections. Despite numerous deconvolution methods that blindly estimate
blurring in either inclusive or exclusive forms, they are practically
challenging due to high computational cost and low image reconstruction
quality. Both conditions of high accuracy and high speed are prerequisites for
high-throughput imaging platforms in digital archiving. In such platforms,
deblurring is required after image acquisition before being stored, previewed,
or processed for high-level interpretation. Therefore, on-the-fly correction of
such images is important to avoid possible time delays, mitigate computational
expenses, and increase image perception quality. We bridge this gap by
synthesizing a deconvolution kernel as a linear combination of Finite Impulse
Response (FIR) even-derivative filters that can be directly convolved with
blurry input images to boost the frequency fall-off of the Point Spread
Function (PSF) associated with the optical blur. We employ a Gaussian low-pass
filter to decouple the image denoising problem for image edge deblurring.
Furthermore, we propose a blind approach to estimate the PSF statistics for two
Gaussian and Laplacian models that are common in many imaging pipelines.
Thorough experiments are designed to test and validate the efficiency of the
proposed method using 2054 naturally blurred images across six imaging
applications and seven state-of-the-art deconvolution methods.Comment: 15 pages, for publication in IEEE Transaction Image Processin
Physics-Driven Turbulence Image Restoration with Stochastic Refinement
Image distortion by atmospheric turbulence is a stochastic degradation, which
is a critical problem in long-range optical imaging systems. A number of
research has been conducted during the past decades, including model-based and
emerging deep-learning solutions with the help of synthetic data. Although fast
and physics-grounded simulation tools have been introduced to help the
deep-learning models adapt to real-world turbulence conditions recently, the
training of such models only relies on the synthetic data and ground truth
pairs. This paper proposes the Physics-integrated Restoration Network (PiRN) to
bring the physics-based simulator directly into the training process to help
the network to disentangle the stochasticity from the degradation and the
underlying image. Furthermore, to overcome the ``average effect" introduced by
deterministic models and the domain gap between the synthetic and real-world
degradation, we further introduce PiRN with Stochastic Refinement (PiRN-SR) to
boost its perceptual quality. Overall, our PiRN and PiRN-SR improve the
generalization to real-world unknown turbulence conditions and provide a
state-of-the-art restoration in both pixel-wise accuracy and perceptual
quality. Our codes are available at \url{https://github.com/VITA-Group/PiRN}.Comment: Accepted by ICCV 202
AT-DDPM: Restoring Faces degraded by Atmospheric Turbulence using Denoising Diffusion Probabilistic Models
Although many long-range imaging systems are designed to support extended
vision applications, a natural obstacle to their operation is degradation due
to atmospheric turbulence. Atmospheric turbulence causes significant
degradation to image quality by introducing blur and geometric distortion. In
recent years, various deep learning-based single image atmospheric turbulence
mitigation methods, including CNN-based and GAN inversion-based, have been
proposed in the literature which attempt to remove the distortion in the image.
However, some of these methods are difficult to train and often fail to
reconstruct facial features and produce unrealistic results especially in the
case of high turbulence. Denoising Diffusion Probabilistic Models (DDPMs) have
recently gained some traction because of their stable training process and
their ability to generate high quality images. In this paper, we propose the
first DDPM-based solution for the problem of atmospheric turbulence mitigation.
We also propose a fast sampling technique for reducing the inference times for
conditional DDPMs. Extensive experiments are conducted on synthetic and
real-world data to show the significance of our model. To facilitate further
research, all codes and pretrained models are publically available at
http://github.com/Nithin-GK/AT-DDPMComment: Accepted to IEEE WACV 202
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