Biospeckle technique for the non-destructive differentiation of bruised and fresh regions of an Indian apple using intensity-based algorithms

Abstract

In the present paper intensity-based algorithms have been applied to differentiate the bruised and fresh regions of an Indian apple through biospeckle technique during its 9 day shelf life. Existing algorithms such as the co-occurrence matrix, inertia moment, absolute value difference, generalized difference, parameterized Fujii, biospeckle activity (BA) value, granulometric size distribution (GSD) and grey-level co-occurrence matrix (GLCM), as well as three new proposed algorithms namely parameterized generalized difference, alternative generalized difference (AGD) and parameterized global average Fujii, have been used for qualitative and quantitative analysis. Co-occurrence matrix and activity level spectral maps have been used for qualitative analysis, whereas mean activity plots, curve of the BA index, GSD plots and texture features have been used for quantitative analysis. The experimental results suggest that overall difference in biospeckle activity between the bruised and fresh regions is maximum for the inertia moment method (521.99). Of the three proposed algorithms AGD gives the maximum overall difference in biospeckle activity (42.35). In addition, the BA value and parameters of the GLCM have also been applied for the first time to distinguish between the bruised and fresh regions of an Indian apple, and it is concluded that both the methods may be used for good differentiation between the bruised and fresh regions of apples.