Accurate positioning for the centre of circular array target based on vanishing points
by Lijun Sun; Shaokui Ma; Tianfei Chen; Ming Yan; Xiaodong Liu
International Journal of Modelling, Identification and Control (IJMIC), Vol. 39, No. 1, 2021

Abstract: Circular array target is widely used in vision measurement systems. The detection of circular targets is usually regarded as ellipse detection after projective transformation. However, the centre of the ellipse is not the actual projection of the centre of the target circle. For this reason, this paper proposes an algorithm for locating the imaging centre of the target circle based on the vanishing points. After completing the extraction and filtering of the ellipse edge, the projective transformation matrix is used to obtain the two vanishing points referring to the coordinate axis direction of the target plane. Then utilising the principle of perspective invariance and the two vanishing points, two pairs of tangent points on the ellipse edge are determined. Finally, the cross point between the lines connecting the two pairs of tangent points is the actual projection point of the target circle. Both simulation experiments and actual experiments demonstrate that the proposed algorithm has the characteristics of simple operation, faster running speed, and higher precision.

Online publication date: Mon, 13-Jun-2022

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Modelling, Identification and Control (IJMIC):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com