Symptoms associated with fungal damage, viral diseases, and immature soybea
n (Glycine max) seeds were characterized using image processing techniques.
A Red, Green, Blue (RGB) color feature-based multivariate decision model d
iscriminated between asymptomatic and symptomatic seeds for inspection and
grading. The color analysis showed distinct color differences between the a
symptomatic and symptomatic seeds. A model comprising six color features in
cluding averages, minimums, and variances for RGB pixel values was develope
d for describing the seed symptoms. The color analysis showed that color al
one did not adequately describe some of the differences among symptoms. Ove
rall classification accuracy of 88% was achieved using a linear discriminan
t function with unequal priors for asymptomatic and symptomatic seeds with
highest probability of occurrence. Individual classification accuracies wer
e asymptomatic 97%, Alternaria spp. 30%, Cercospora spp. 83%, Fusarium spp.
62%, green immature seeds 91%, Phomopsis spp. 45%, soybean mosaic potyviru
s (black) 81%, and soybean mosaic potyvirus (brown) 87%. The classifier per
formance was independent of the year the seed was sampled. The study was su
ccessful in developing a color classifier and a knowledge domain based on c
olor for future development of intelligent automated grain grading systems.