Fluorescence lifetime imaging (FLI) plays an important role in detection of different fluorescence substances. However, when background light is strong and image noise is high, FLI is hard to discriminate substances with approximate fluorescence lifetime. An enhanced time-resolved fluorescence imaging method is proposed. In the method, a dual-gated intensity-correlation enhancement algorithm is developed. Compared with traditional rapid fluorescence lifetime determination imaging method, the method focuses on improve image contrast and can effectively remove background noise. It utilizes two fluorescence intensity images at different delay times, and adaptively chooses the filter threshold and the up threshold to remove noise and enhance contrast. The thresholds are determined by the distribution of image variance. In proof experiments, three brands of highlighters with the same color have close fluorescence lifetime, and the proposed method shows their fine fluorescence difference. The simulation and experimental results prove that the method can improve the ability of time-resolved fluorescence imaging.
|