Journal of the Korean Society for Precision Engineering (한국정밀공학회지)
- Volume 16 Issue 8
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- Pages.16-22
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- 1999
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- 1225-9071(pISSN)
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- 2287-8769(eISSN)
Estimation of Real Boundary with Subpixel Accuracy in Digital Imagery
디지털 영상에서 부화소 정밀도의 실제 경계 추정
- Published : 1999.01.01
Abstract
In this paper, an efficient algorithm for estimating real edge locations to subpixel values is described. Digital images are acquired by projection into image plane and sampling process. However, most of real edge locations are lost in this process, which causes low measurement accuracy. For accurate measurement, we propose an algorithm which estimates the real boundary between two adjacent pixels in digital imagery, with subpixel accuracy. We first define 1D edge operator based on the moment invariant. To extend it to 2D data, the edge orientation of each pixel is estimated by the LSE(Least Squares Error)line/circle fitting of a set of pixels around edge boundary. Then, using the pixels along the line perpendicular to the estimated edge orientation the real boundary is calculated with subpixel accuracy. Experimental results using real images show that the proposed method is robust in local noise, while maintaining low measurement error.
Keywords