Recognition of Broken Corn Seeds Based on Contour Curvature

Aiming at the problem on determining breakage rate of corn seeds in real time, a method for identifying broken corn seeds was presented based on contour curvature. The broken corn seeds were classified into three classes according to damage position and level. Firstly, the seed contour was rebuilt with Fourier descriptors to achieve smooth contour. Then, contour curvature was calculated and the point with maximum curvature value on the contour was taken as an endpoint of the seed major axis, so the position of major axis was determined. Two kinds of broken seeds were identified by judging their shape symmetry. Lastly, other broken seeds were identified using two parameters. One parameter was the difference between maximum and sub-maximum peaks of curvature. The other was the frequency of the curvature line crossing the mean line. The experimental results on three corn varieties show that the average recognition rate of broken corn seeds is 92.4% and the method is valuable for engineering application.