Dynamic speckle analysis using the event-based block matching algorithm

Abstract

Dynamic speckle analysis (DSA) is a non-invasive method to detect movements of the inspected objects. By illuminating the observed sample using a coherent light source, motion information can be obtained from a series of reflecting speckle patterns. Conventional DSA methods record the intensity of the speckle patterns using a frame-based imaging sensor. Here, we propose a novel implementation of DSA using the event sensor which captures the brightness changes of the dynamic speckle patterns with high temporal resolution and low latency. Our method is based on block matching algorithm in which the captured event stream is divided into many non-overlapping blocks and motion information can be computed by searching for the most likely blocks. The experiment results demonstrate the feasibility of our proposed method in different dynamic levels and this work will be beneficial for various applications such as biomedical imaging and material science.