Computer Vision System for Analysis of Geometrical Characteristics of Agricultural Products and Microscopic Particles (I) -Algorithms for Automatic Threshold Selection-

농산물 및 미립자의 기하학적 특성 분석을 위한 컴퓨터 시각 시스템(I) -자동(自動) 문턱값 설정(設定) 알고리즘-

The main objective of this paper is to evaluate and modify the existing algorithms for the automatic threshold selection. Four existing algorithms were evaluated quantitatively using test images of coffee droplets and an apple. The images had the different area ratio of the object to the image size, different average gray values between the object and the background, and different S/N ratio of the Gaussian noise. The result showed that Histogram Clustering Method and Maximum Entropy Method were better than Moment Preserving Method and Simple Image Statistic Method in automatic thresholding.