Resolution enhancement of CT images using multiple low resolution sub-pixel shifted images

Sub-pixel shifted low resolution images contain new information about the same scene which can be exploited to generate high resolution (HR) image. In computed tomography (CT), HR image reconstruction using limited projection data is always desired but it requires iterative techniques that involve high computational cost. In this paper, we propose a computationally efficient and noise robust HR image reconstruction method using multiple low resolution images. The work is divided into two stages: first we demonstrate how to reconstruct a number of low resolution images utilizing the same projection data and then we employ standard interpolation/super resolution technique to obtain an HR image. The method is not only computationally efficient but also improves signal to noise ratio of the reconstructed images. The simulation results show that the proposed method can produce better images compared to the state-of-the-art techniques.