In this paper, we propose a method for detecting circular shapes with subpixel accuracy. First, the geometric properties of circles have been used to find the diameters as well as the circumference pixels. The center and radius are then estimated by the circumference pixels. Both synthetic and real images have been tested by the proposed method. The experimental results show that the new method is efficient.


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This paper is partially supported by National Science Council, ROC under grant no. NSC 97-2221-E-214-040 and NSC 97-2918-I-214-002.

Keywords and Phrases

Circle detection; Circular objects; Circular shape; Geometric properties; Hough transformation; Least squares estimation; Real images; Subpixel; Subpixel accuracy; Subpixel detection; Hough Transformation; Sub pixels; Pixels; Engineering; Technology

International Standard Serial Number (ISSN)

2010-376X; 2010-3778

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2009 World Academy of Science, Engineering and Technology, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Aug 2009

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Business Commons