Real-time correction of transverse dislocation and distortion in probe-based confocal laser endomicroscopy imaging

Abstract

High speed scanning system based on resonant scanner can improve the imaging speed of probe-based confocal laser endomicroscopy (pCLE), which makes pCLE be a very effective tool to observe cell tissue morphology in vivo. However, since the speed of resonant scanner changes nonlinearly, transverse distortion will occur when the digitizer collects the image data at a constant rate. Moreover, accurate turning time is hard to be obtained due to the limitation of scanner hardware, although synchronous square wave signals are used for reference. Therefore, it is difficult to accurately segment the bidirectional scanned data into two adjacent lines of the image, which results in image dislocation. In this work, the offset value of each line is obtained by estimating the overall dislocation and local dislocation of the image respectively. Then, the start time of the sampling and sampling interval are adjusted based on the scanner speed to correct the image in real-time by FPGA. As a result, the dislocation and distortion of the image are corrected at video rates.