Open AccessEnsemble averaging laser speckle contrast imaging: statistical model of improvement as function of static scatterers
Author(s) -
Péter Földesy,
Máté Siket,
Imre Jánoki,
Kornél Demeter,
Ádám Nagy
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.428394
Subject(s) - speckle pattern , optics , decorrelation , granularity , contrast (vision) , inter frame , computer science , image resolution , imaging phantom , speckle noise , frame (networking) , physics , reference frame , algorithm , telecommunications , operating system
The appearance of the common artifacts of laser speckle contrast imaging (LSCI), namely the granularity in flow rate estimation caused by static scatterers, is a well-known phenomenon. This artifact can be greatly reduced in spatial speckle contrast calculation using interframe decorrelated illumination, forcing true ensemble averaging. We propose a statistical model, which describes the effect of multiple image acquisitions on the contrast map quality when the illumination stable and when the illumination is decorrelated frame by frame. We investigate the improvement as a function of the ratio of dynamic and static scatterers by formulating a statistical distribution based model, using in simulation, flow phantom and in vivo experiments. Our main finding is that the ensemble averaging yields limited improvement in several practical cases due to the highly heterogeneous scatterer structure of living tissues.