Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital Image

Circular targets are often utilized in photogrammetry and a circle on a plane is projected as an ellipse onto an oblique image. This paper reports an experiment conducted to investigate whether the measurement accuracy of the center location of an ellipse on a digital image oscillates as its dimensi...

Full description

Bibliographic Details
Main Author: R. Matsuoka
Format: Article
Language:English
Published: Copernicus Publications 2014-08-01
Series:The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
Online Access:http://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XL-3/211/2014/isprsarchives-XL-3-211-2014.pdf
_version_ 1830345125945933824
author R. Matsuoka
author_facet R. Matsuoka
author_sort R. Matsuoka
collection DOAJ
description Circular targets are often utilized in photogrammetry and a circle on a plane is projected as an ellipse onto an oblique image. This paper reports an experiment conducted to investigate whether the measurement accuracy of the center location of an ellipse on a digital image oscillates as its dimension increases. The experiment was executed by the Monte Carlo simulation using 1024 synthesized images of which the centers were randomly distributed in one pixel for each ellipse. We investigated four typical measurement methods: intensity-weighted centroid method, non-iterative ellipse fitting, iterative ellipse fitting with the star operator, and least-squares matching. Three flattenings 0.00, 0.25, 0.50, and three rotation angles 0.0°, 22.5°, 45.0° were investigated in the experiment. The experiment results clearly show that the measurement accuracy by all the investigated methods would oscillate as the dimension of an ellipse increases. The measurement accuracy by the intensity-weighted centroid method and the non-iterative ellipse fitting would oscillate smoothly, while that by the least-squares matching would oscillate considerably roughly. It would be impossible to determine the cycle of the oscillation except the measurement accuracy by the intensity-weighted centroid method and the non-iterative ellipse fitting when the rotation angle of an ellipse is 0.0° and 45.0°. The experiment results indicate that the flattening and the rotation angle of an ellipse would affect the cycle of the oscillation as well.
first_indexed 2024-12-19T22:38:51Z
format Article
id doaj.art-7729ac8babf743d4b94b8fab80c29cf6
institution Directory Open Access Journal
issn 1682-1750
2194-9034
language English
last_indexed 2024-12-19T22:38:51Z
publishDate 2014-08-01
publisher Copernicus Publications
record_format Article
series The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
spelling doaj.art-7729ac8babf743d4b94b8fab80c29cf62022-12-21T20:03:08ZengCopernicus PublicationsThe International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences1682-17502194-90342014-08-01XL-321121810.5194/isprsarchives-XL-3-211-2014Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital ImageR. Matsuoka0Research and Development Division, Kokusai Kogyo Co., Ltd., 2-24-1 Harumi-cho, Fuchu, Tokyo 183-0057, JapanCircular targets are often utilized in photogrammetry and a circle on a plane is projected as an ellipse onto an oblique image. This paper reports an experiment conducted to investigate whether the measurement accuracy of the center location of an ellipse on a digital image oscillates as its dimension increases. The experiment was executed by the Monte Carlo simulation using 1024 synthesized images of which the centers were randomly distributed in one pixel for each ellipse. We investigated four typical measurement methods: intensity-weighted centroid method, non-iterative ellipse fitting, iterative ellipse fitting with the star operator, and least-squares matching. Three flattenings 0.00, 0.25, 0.50, and three rotation angles 0.0°, 22.5°, 45.0° were investigated in the experiment. The experiment results clearly show that the measurement accuracy by all the investigated methods would oscillate as the dimension of an ellipse increases. The measurement accuracy by the intensity-weighted centroid method and the non-iterative ellipse fitting would oscillate smoothly, while that by the least-squares matching would oscillate considerably roughly. It would be impossible to determine the cycle of the oscillation except the measurement accuracy by the intensity-weighted centroid method and the non-iterative ellipse fitting when the rotation angle of an ellipse is 0.0° and 45.0°. The experiment results indicate that the flattening and the rotation angle of an ellipse would affect the cycle of the oscillation as well.http://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XL-3/211/2014/isprsarchives-XL-3-211-2014.pdf
spellingShingle R. Matsuoka
Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital Image
The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences
title Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital Image
title_full Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital Image
title_fullStr Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital Image
title_full_unstemmed Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital Image
title_short Oscillation of the Measurement Accuracy of the Center Location of an Ellipse on a Digital Image
title_sort oscillation of the measurement accuracy of the center location of an ellipse on a digital image
url http://www.int-arch-photogramm-remote-sens-spatial-inf-sci.net/XL-3/211/2014/isprsarchives-XL-3-211-2014.pdf
work_keys_str_mv AT rmatsuoka oscillationofthemeasurementaccuracyofthecenterlocationofanellipseonadigitalimage