Abstract-Reconstruction Methods in THz Single-pixel Imaging

Martin Burger, Janic Föcke, Lukas Nickel, Peter Jung, Sven Augustin

https://arxiv.org/abs/1903.08893

The aim of this paper is to discuss some advanced aspects of image reconstruction in single-pixel cameras, focusing in particular on detectors in the THz regime. We discuss the reconstruction problem from a computational imaging perspective and provide a comparison of the effects of several state-of-the art regularization techniques.
Moreover, we focus on some advanced aspects arising in practice with THz cameras, which lead to nonlinear reconstruction problems: the calibration of the beam reminiscent of the Retinex problem in imaging and phase recovery problems. Finally we provide an outlook to future challenges in the area.

Abstract-A High Precision Terahertz Wave Image Reconstruction Algorithm

Qijia Guo 1, Tianying Chang 1,2,*, Guoshuai Geng 1, Chengyan Jia 1 and Hong-Liang Cui 1

1

School of Instrumentation Science and Electrical Engineering, Jilin University, Changchun 130012, China

2

Institute of Automation, Shandong Academy of Sciences, Jinan 250014, China

*

Correspondence: Tel.: +86-186-1251-9976

Academic Editors: Vincenzo Spagnolo and Dragan Indjin

http://www.mdpi.com/1424-8220/16/7/1139/htm

With the development of terahertz (THz) technology, the applications of this spectrum have become increasingly wide-ranging, in areas such as non-destructive testing, security applications and medical scanning, in which one of the most important methods is imaging. Unlike remote sensing applications, THz imaging features sources of array elements that are almost always supposed to be spherical wave radiators, including single antennae. As such, well-developed methodologies such as Range-Doppler Algorithm (RDA) are not directly applicable in such near-range situations. The Back Projection Algorithm (BPA) can provide products of high precision at the the cost of a high computational burden, while the Range Migration Algorithm (RMA) sacrifices the quality of images for efficiency. The Phase-shift Migration Algorithm (PMA) is a good alternative, the features of which combine both of the classical algorithms mentioned above. In this research, it is used for mechanical scanning, and is extended to array imaging for the first time. In addition, the performances of PMA are studied in detail in contrast to BPA and RMA. It is demonstrated in our simulations and experiments described herein that the algorithm can reconstruct images with high precision.