Research on sub-pixel shift-based super-resolution imaging by introducing wave-front coding technique

By capturing a series of low-resolution images which have known or unknown sub-pixel displacement between each other, high resolution image could be reconstructed through algorithms such as IBP, POCS and so on. This technique mainly aims to solve the problem of aliasing effect caused by under-sampling but one problem exists. While applying sub-pixel shift based super-resolution reconstruction, point spread function is used to simulate the imaging process but usually the point spread function corresponding to the low-resolution imaging system is used, which does not match reconstruction in high-resolution grid. According to our previous researches, the wave-front coding technique could be used to realize single image amplification based super-resolution reconstruction because the point spread function corresponding to the high-resolution grid could be digitally generated in a more accurate way. In this manuscript, the rotationally symmetric wave-front coding technique and the sub-pixel shift based super-resolution imaging are combined together and there are two advantages. First, because of decrease of the magnitude of optical transfer function caused by wave-front coding, the aliasing effect in the intermediate images is reduced keeping pitch size unchanged. Second, while doing the reconstruction in high-resolution grid, the computed point spread function corresponding to the high-resolution grid is used, which better matches the high-resolution grid. The numerical results demonstrate that better image could be obtained by incorporating rotationally symmetric wave-front coding into sub-pixel shift based super-resolution imaging.