Non-local blind hyperspectral image super-resolution via 4d sparse tensor factorization and low-rank

Abstract

Hyperspectral image (HSI) super-resolution is a technique to improve the spatial resolution of a HSI for better visual perception and down stream applications. This is a very ill-posed inverse problem and is often solved by fusing the low-resolution (LR) HSI with a high-resolution (HR) multispectral image (MSI). It is more challenging for blind HSI super-resolution, i.e., when the spatial degradation operators are completely unknown. In this paper, we propose a novel sparse tensor factorization model for the task of blind HSI super-resolution using the spatial non-local self-similarity and spectral global correlation of HSIs. Image clustering method is employed to collect some similar 3D cubes of HSIs which can be formed as some 4D image clusters with high correlation. We conduct cluster wise computation to not only save computation time but also to introduce a non-local regularity originated from the redundancy of cubes. By using the sparsity of tensor decomposition and the low-rank in non-local self-similarity direction underlying 4D similar clusters, we design a sparse tensor regularization term, which preserves the spatial-spectral structural correlation of HSIs. In addition, we present a proximal alternating direction method of multipliers (ADMM) based algorithm to efficiently solve the proposed model. Numerical experiments demonstrate that the proposed model outperforms many state-of-the-art HSI super-resolution methods.

An Edge-Directed Diffusion Equation-Based Image Restoration Approach for Font Generation

“…Local designers are also digging Chinese traditional art elements, and spare no effort in font design, especially the profound and inexhaustible design elements of Chinese culture [10], [11]. At the same time, with the development of computer design technology, information dissemination is convenient and fast, and the exploration of new font design is increasing day by day [12], [13]. Today, the wide application of digital media has opened up a new development field for Chinese character design, and at the same time provided an unprecedented development opportunity [14].…”