Single-shot temporal speckle correlation imaging using rolling shutter image sensors

Abstract

We propose a single-shot wide-field imaging method that maps local temporal intensity decorrelations of dynamic speckle fields. Our method, named rolling shutter speckle imaging (RSSI), utilizes short time intervals between each row of a rolling shutter complementary metal–oxide–semiconductor (RS-CMOS) image sensor to discern fast temporal changes in the speckle field, which otherwise requires sequential measurements with high-speed cameras. RSSI generates elongated speckle patterns on an RS-CMOS image sensor and quantifies temporal decorrelations of speckle fields from row-by-row intensity correlations (RICs) within a single image. To quantify the local speckle decorrelation times of dynamic scattering media, we derived a theoretical model for RIC and verified the model using numerical simulations and flow-phantom experiments. Further, our in vivo imaging results show that RSSI can map the flow rate distributions in cerebral blood vessels with the correction of static scattering in the tissue, demonstrating that RSSI is a powerful and cost-effective imaging tool for in vivo quantitative blood flow measurements.