Half-pixel sliding window processing for fourfold resolution improvement on single-shot quantitative phase imaging with polarization cameras

Phase to polarization encoding (P2P) has emerged as a potent tool for quantitative phase imaging (QPI), offering on-axis single-shot QPI with high precision by using a polarization camera, in which four CMOS pixels with different polarizer orientations are combined to form a super-pixel for local polarization analysis, but unfortunately at the expense of a 4× resolution degradation of the underlining polarization imaging. In this paper, we propose and demonstrate a novel methodology called half-pixel sliding window (HPSW) processing, which enables us to restore the spatial resolution of the P2P-QPI to the original CMOS-pixel size of the polarization camera and therefore achieve nearly fourfold resolution enhancement for analyzing dynamic biological samples with the P2P-QPIs. By seamlessly integrating this technique into existing data processing, we anticipate a significant advancement in the ability to capture intricate cellular dynamics and unveil finer details within biological specimens, which represents a pivotal step towards realizing the full potential of P2P-QPI in advancing the understanding of complex biological processes.