148 research outputs found
Model Inspired Autoencoder for Unsupervised Hyperspectral Image Super-Resolution
This paper focuses on hyperspectral image (HSI) super-resolution that aims to
fuse a low-spatial-resolution HSI and a high-spatial-resolution multispectral
image to form a high-spatial-resolution HSI (HR-HSI). Existing deep
learning-based approaches are mostly supervised that rely on a large number of
labeled training samples, which is unrealistic. The commonly used model-based
approaches are unsupervised and flexible but rely on hand-craft priors.
Inspired by the specific properties of model, we make the first attempt to
design a model inspired deep network for HSI super-resolution in an
unsupervised manner. This approach consists of an implicit autoencoder network
built on the target HR-HSI that treats each pixel as an individual sample. The
nonnegative matrix factorization (NMF) of the target HR-HSI is integrated into
the autoencoder network, where the two NMF parts, spectral and spatial
matrices, are treated as decoder parameters and hidden outputs respectively. In
the encoding stage, we present a pixel-wise fusion model to estimate hidden
outputs directly, and then reformulate and unfold the model's algorithm to form
the encoder network. With the specific architecture, the proposed network is
similar to a manifold prior-based model, and can be trained patch by patch
rather than the entire image. Moreover, we propose an additional unsupervised
network to estimate the point spread function and spectral response function.
Experimental results conducted on both synthetic and real datasets demonstrate
the effectiveness of the proposed approach
Interpretable Hyperspectral AI: When Non-Convex Modeling meets Hyperspectral Remote Sensing
Hyperspectral imaging, also known as image spectrometry, is a landmark
technique in geoscience and remote sensing (RS). In the past decade, enormous
efforts have been made to process and analyze these hyperspectral (HS) products
mainly by means of seasoned experts. However, with the ever-growing volume of
data, the bulk of costs in manpower and material resources poses new challenges
on reducing the burden of manual labor and improving efficiency. For this
reason, it is, therefore, urgent to develop more intelligent and automatic
approaches for various HS RS applications. Machine learning (ML) tools with
convex optimization have successfully undertaken the tasks of numerous
artificial intelligence (AI)-related applications. However, their ability in
handling complex practical problems remains limited, particularly for HS data,
due to the effects of various spectral variabilities in the process of HS
imaging and the complexity and redundancy of higher dimensional HS signals.
Compared to the convex models, non-convex modeling, which is capable of
characterizing more complex real scenes and providing the model
interpretability technically and theoretically, has been proven to be a
feasible solution to reduce the gap between challenging HS vision tasks and
currently advanced intelligent data processing models
Fusing Multiple Multiband Images
We consider the problem of fusing an arbitrary number of multiband, i.e.,
panchromatic, multispectral, or hyperspectral, images belonging to the same
scene. We use the well-known forward observation and linear mixture models with
Gaussian perturbations to formulate the maximum-likelihood estimator of the
endmember abundance matrix of the fused image. We calculate the Fisher
information matrix for this estimator and examine the conditions for the
uniqueness of the estimator. We use a vector total-variation penalty term
together with nonnegativity and sum-to-one constraints on the endmember
abundances to regularize the derived maximum-likelihood estimation problem. The
regularization facilitates exploiting the prior knowledge that natural images
are mostly composed of piecewise smooth regions with limited abrupt changes,
i.e., edges, as well as coping with potential ill-posedness of the fusion
problem. We solve the resultant convex optimization problem using the
alternating direction method of multipliers. We utilize the circular
convolution theorem in conjunction with the fast Fourier transform to alleviate
the computational complexity of the proposed algorithm. Experiments with
multiband images constructed from real hyperspectral datasets reveal the
superior performance of the proposed algorithm in comparison with the
state-of-the-art algorithms, which need to be used in tandem to fuse more than
two multiband images
Hyperspectral Super-Resolution with Coupled Tucker Approximation: Recoverability and SVD-based algorithms
We propose a novel approach for hyperspectral super-resolution, that is based
on low-rank tensor approximation for a coupled low-rank multilinear (Tucker)
model. We show that the correct recovery holds for a wide range of multilinear
ranks. For coupled tensor approximation, we propose two SVD-based algorithms
that are simple and fast, but with a performance comparable to the
state-of-the-art methods. The approach is applicable to the case of unknown
spatial degradation and to the pansharpening problem.Comment: IEEE Transactions on Signal Processing, Institute of Electrical and
Electronics Engineers, in Pres
- …