LOCATION AND CHARACTERIZATION OF THE STEM-CALYX AREA ON ORANGES BY COMPUTER VISION

Three image analysis methods were studied and evaluated to solve the p roblem of removing long stems attached to mechanically harvested orang es: colour segmentation based on linear discriminant analysis, contour curvature analysis, and a thinning process which involves iterating u ntil the stem becomes a skeleton. These techniques are able to determi ne the presence or absence of a stem with certainty, to locate the ste ms from random views with more than 90% accuracy and from profile imag es with an accuracy ranging from 92.4% to 100% depending on the method used. Finally, determination of the length and cutting point of the s tem is achieved with only 3.8% of failures. (C) 1996 Silsoe Research I nstitute