Characterization of a paint drying process through granulometric analysis of speckle dynamic patterns

ADRIANA MAVILIO; MARGARITA FERNANDEZ; MARCELO TRIVI; HECTOR RABAL; RICARDO ARIZAGA

SIGNAL PROCESSING

ELSEVIER SCIENCE BV

Año: 2010 vol. 90 p. 1623 - 1630

0165-1684

Dynamic speckle patterns are generated by laser light scattering on surfaces that exhibitsome kind of activity, due to physical or biological processes.The characterization of this process is carried out by studying the texture changes ofauxiliary images: temporal history of the speckle pattern (THSP).The drying process of water borne paint is studied through a method based onmathematical morphology applied to the THSP image processing. It is based onobtaining the granulometry of these images and their characteristic granulometricspectrum. From the granulometric size distribution of each THSP image four parametersare obtained: mean length, standard deviation, asymmetry and kurtosis. Theseparameters are found to be suitable as texture features.The Mahalanobis distance is calculated between the texture features of the THSPimages representative of the temporary stages of the drying process and the features ofthe final stage or pattern texture. The behavior of the distance function describessatisfactorily the drying process of the water borne paint. The results are compared withother methods.Compared with others, the granulometric method reported in this paper distinguishedby its simplicity and easy implementation and can be used to characterize theevolution of any process recorded through dynamic speckles.