Alternative measures for biospeckle image analysis

Abstract

Biospeckle is a technique whose purpose is to observe and study the underlying activity of some material. It has its roots in optical physics, and its first step is an image acquisition process that produces a video sequence of the reflection of a laser. The video content can be analyzed to have an interpretation of the activity of the observed material. The literature on this subject presents several different measures for analyzing the video sequence. Three of the most popular measures are the generalized difference (GD), the weighted generalized difference (WGD), and Fujii's method. These measures have drawbacks such as high computation time or limited visual quality of the results. In this paper, we propose (i) an alternative O(n) algorithm for the computation of the GD, (ii) an alternative measure based on the GD, (iii) an alternative measure based on the WGD, and (iv) a generalized definition of the Fujii's method with better visual quality. We discuss the similarities between the new measures and the existent ones, showing when they are applicable. We prove the gain in time computation. The proposed measures will help researchers to gain time during their research and to be able to develop faster tools based on biospeckle application.

Detection, differentiation and mapping of different states of blue mold disease of Indian gooseberry (Emblica officinalis G.) using a biospeckle technique

“…Spectral maps are obtained using Fujii (Saúde et al 2012), Inverse Fujii (Saúde et al 2012), Alternative Fujii (Minz and Nirala 2014) and Parameterised Fujii algorithms (Saúde et al 2012) and they are given respectively as…”

“…Existing methods-GD, PGD and AGD methods. Spectral activity maps are also obtained using GD (Saúde et al 2012), PGD (Kumari and Nirala 2016) and AGD (Kumari and Nirala 2016) algorithms and they are given respectively as…”

Assessment of Bio-activity of the fruits using intensity based methods

“…The Fujii method gives better result compared to GD only if the sample is uniformly illuminated but it shows negative result when sample is illuminated non-uniformly; means the area which falls under low illumination shows high activity [15]. It is because that Fujii method is sensitive in low intensity regions [11].…”

Study of hygroscopic properties of the mixture of porous and non-porous materials by using optical techniques

“…If the sample is not rigid, the speckle pattern evolves according to the changes produced on the surface of the sample. These dynamic speckle images have been analyzed using qualitative and quantitative methods Rabal and Braga (2008); Braga et al (2017). Qualitative methods allow segmentation of the image according to its speckle activity, such as generalized differences Arizaga et al (2002), LASCA Arizaga et al (2006), Fujii Fujii et al (1987); Ansari and Nirala (2015); Minz and Nirala (2014); Sauude et al ( 2012) and temporal differences Ansari and Mujeeb (2018) methods, among others Rabal and Braga (2008).…”

“…The dynamic speckle technique enables the determination of sample characteristics across multiple applications. Rabal and Braga (2008). In particular, in Ref DaryMojica-Sepulveda et al (2018), The feasibility of utilizing the Dynamic Speckle technique as an affordable and straightforward complementary tool for determining textural parameters is demonstrated.…”