期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2010
卷号：XXXVIII - Part 3A
页码：31-36
出版社：Copernicus Publications
摘要：Our previous paper reported an experiment conducted in order to evaluate measurement methods of the center location of a circle by using simulated images of various sizes of circles. The variances of the measurement errors of the centroid methods in the experiment appeared to oscillate on a one-pixel cycle in diameter. This paper reports an analysis of the dependence of the measurement accuracy of the center location of a circle by the centroid methods on its diameter. Two centroid methods: intensity- weighted centroid method (WCM) and unweighted centroid method using a binary image created by thresholding (BCM) are investigated. Since general expressions representing the measurement accuracy by both WCM and BCM are unable to be obtained analytically, the variances of the measurement errors by both methods are obtained by numerical integration. From the results by the numerical integration, we conclude that sampling in digitization would cause the measurement accuracy of the center location of a circle by both WCM and BCM to oscillate on a one-pixel cycle in diameter. The results show that the variance of measurement errors by WCM can be expressed by the combination of the inverse proportion to the cube of the diameter and the oscillation on a one-pixel cycle in diameter. On the other hand, the variance of the measurement errors by BCM should approximate to the combination of the inverse proportion to the diameter and the oscillation on a one-pixel cycle in diameter
关键词：Analysis; Sampling; Measurement; Accuracy; Digital
