Link to home

Color Classifier for Symptomatic Soybean Seeds Using Image Processing

April 1999 , Volume 83 , Number  4
Pages  320 - 327

Irfan S. Ahmad , Research Associate , John F. Reid , Professor , Marvin R. Paulsen , Professor, Department of Agricultural Engineering, University of Illinois at Urbana-Champaign, Urbana 61801 , and James B. Sinclair , Professor, Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana 61801



Go to article:
Accepted for publication 25 November 1998.
ABSTRACT

Symptoms associated with fungal damage, viral diseases, and immature soybean (Glycine max) seeds were characterized using image processing techniques. A Red, Green, Blue (RGB) color feature-based multivariate decision model discriminated between asymptomatic and symptomatic seeds for inspection and grading. The color analysis showed distinct color differences between the asymptomatic and symptomatic seeds. A model comprising six color features including averages, minimums, and variances for RGB pixel values was developed for describing the seed symptoms. The color analysis showed that color alone did not adequately describe some of the differences among symptoms. Overall classification accuracy of 88% was achieved using a linear discriminant function with unequal priors for asymptomatic and symptomatic seeds with highest probability of occurrence. Individual classification accuracies were asymptomatic 97%, Alternaria spp. 30%, Cercospora spp. 83%, Fusarium spp. 62%, green immature seeds 91%, Phomopsis spp. 45%, soybean mosaic potyvirus (black) 81%, and soybean mosaic potyvirus (brown) 87%. The classifier performance was independent of the year the seed was sampled. The study was successful in developing a color classifier and a knowledge domain based on color for future development of intelligent automated grain grading systems.


Additional keywords: feature space, grain quality, machine vision

© 1999 The American Phytopathological Society