Application of Image Texture Analysis for Evaluation of X-Ray Images of Fungal-Infected Maize Kernels

Application of an expert system of X‐ ray micro computed tomography imaging for identification of Sitophilus oryzae infestation in stored rice grains

“…The contrast created in the rice grain images is a result of the difference in the attenuation with X‐rays by the voids and anatomical features (endosperm and germ) within the S. oryzae ‐infested rice grain . The brighter regions (white, off white) correspond to a higher attenuation level, hoff white) correspond to a higher attenuation level, hence denser regions, whereas the dark areas (Grey, blue, green) indicate pores or voids with lower attenuation with respect to the solid fraction . Fresh samples (Fig.…”

“…Principal component analysis (PCA) is multivariate pattern recognition technique in which the original variables are transformed into a new set of latent variables termed principal components (PCs) . In a PCA model each component is characterized by two complementary sets of features: the loading PC, which gives the direction of largest variability, and the score value, which symbolizes the projection of each samples onto PCs which may be either differences or similarities . Thus, the first PC defines the maximum variance and the second PC is orthogonal to the first PC and has the second greatest variance.…”

“…Its 3D imaging ability also facilitates viewing the food product from different angles . X‐ray micro CT works by using the contrast X‐ray attenuation that arises from the density differences in images to distinguish between the various components in a food product . Images are acquired in micro CT by mounting the sample on a rotary stage and projecting X‐rays through the sample in different directions.…”

“…High attenuated regions correspond to high density areas with a brighter 2D image and vice versa . Rotation of the sample by 180° or 360° at fixed angular distances gives a number of 2D projections that can then be reconstructed into a 3D volume . Consequently, the 3D volume is either represented as a whole or in the form of slices at different directions and depths .…”

“…In the field of food science, X‐ray micro CT has found wide application, as summarized by Schoeman et al . In cereals it has been used for the determination of the density and volume of the maize, 3D visualization of damage to wheat kernel internal structure by insect infestation and sprouting, rice strain characterization by differences in distribution of pore size, heating effects on rice kernels, and effects of roasting on the microstructure of wheat and maize …”