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Proceedings Paper

Edge detection in multisurface objects in a homogeneous background using the phase-shift fringe projection method
Author(s): Mani Maran Ratnam
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Paper Abstract

This paper presents a technique for detecting edges of a multi-surface object placed in a background having grayscale intensity same as that of the object surface, i.e. in a homogeneous background. The various surfaces of the object also have the same intensities. For these types of objects an intensity gradient does not exist across the image and thus common intensity based edge detectors such as Sobel, Prewitt and Canny are unable to detect the edges successfully. In the proposed technique, sinusoidally-coded structured light is projected obliquely onto the object surface that is viewed from a normal position. The different illumination and viewing directions cause the projected light pattern (fringes) to break at the edges of the object due to the presence of a height difference between the various surfaces of the object and its background. By locating the positions of the intensity break points in the image it is possible to locate the various edges of the object. The main drawbacks of this technique is that the accuracy of the edge detection is greatly affected by noise. However, by using the phase-shift method and processing the resulting phase image to extract edges it was found that the accuracy is almost unaffected by the presence noise. The algorithms for the proposed edge detection technique were developed based on simulated images and later applied to real images with suitable modifications.

Paper Details

Date Published: 30 May 2000
PDF: 8 pages
Proc. SPIE 4067, Visual Communications and Image Processing 2000, (30 May 2000); doi: 10.1117/12.386703
Show Author Affiliations
Mani Maran Ratnam, Univ. Sains Malaysia (Malaysia)

Published in SPIE Proceedings Vol. 4067:
Visual Communications and Image Processing 2000
King N. Ngan; Thomas Sikora; Ming-Ting Sun, Editor(s)

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