Super-resolution reconstruction for terahertz imaging based on sub-pixel gradient field transform

This paper presents the gradient-guided image super-resolution reconstruction for terahertz imaging to improve the image quality, taking advantage of super-resolution reconstruction based on adaptive super-pixel gradient field transform. Moreover, spatial entropy-based enhancement and a bilateral filter are introduced to ensure better performance of the reconstruction. Furthermore, we compare the performance of reconstruction operated on terahertz images with frequencies of 0.1 THz, 0.3 THz, 0.5 THz, and 0.7 THz. Experimental results demonstrate that this method successfully improves the image quality and reconstruct high-resolution images from low-resolution images with the peak signal-to-noise ratio and structural similarity index improved. In addition, the signal frequency and intensity are demonstrated to affect the performance of reconstruction.