Open AccessAdaptive terahertz image super-resolution with adjustable convolutional neural network
Author(s) -
Yade Li,
Weidong Hu,
Xin Zhang,
Zhihao Xu,
Jiaqi Ni,
L.P. Ligthart
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.394943
Subject(s) - terahertz radiation , optics , interpolation (computer graphics) , image resolution , computer science , convolutional neural network , point spread function , artificial intelligence , image restoration , aperture (computer memory) , image quality , image processing , computer vision , image (mathematics) , physics , acoustics
During the real-aperture-scanning imaging process, terahertz (THz) images are often plagued with the problem of low spatial resolution. Therefore, an accommodative super-resolution framework for THz images is proposed. Specifically, the 3D degradation model for the imaging system is firstly proposed by incorporating the focused THz beam distribution, which determines the relationship between the imaging range and the corresponding image restoration level. Secondly, an adjustable CNN is introduced to cope with this range dependent super-resolution problem. By simply tuning an interpolation parameter, the network can be adjusted to produce arbitrary restoration levels between the trained fixed levels without extra training. Finally, by selecting the appropriate interpolation coefficient according to the measured imaging range, each THz image can be coped with its matched network and reach the outstanding super-resolution effect. Both the simulated and real tested data, acquired by a 160 ∼ 220 GHz imager, have been used to demonstrate the superiority of our method.