TY - GEN

T1 - Hybrid approach for extraction of dominant points from digital curves

AU - Chen, L. C.

AU - Rau, J. Y.

AU - Wu, R. H.

PY - 1994/12/1

Y1 - 1994/12/1

N2 - In this investigation, we propose a scheme which integrates the two complementary approaches, i.e., the raster approach and the vector approach, to minimize the number of feature points but still preserve the shape of digital curves with high fidelity. The raster form of the digital curve is first encoded in the Freeman chain code space. Then the second order derivative operator combined with a Gaussian filter is applied to detect zero crossings. The turning points on the curve detected as zero crossings in Freeman chain code space are then transformed to the image space. The second stage is then applying dynamic strip algorithm to further eliminate unnecessary points remaining in the first stage. In order to avoid over- elimination of the points, the maximum length of the strip may also be assigned in the scheme. To quantitatively analyze the performance of the proposed scheme, the perpendicular distance of each point on the original curve to the fitted line segment characterized by the dominant points is calculated. The applicability of the proposed scheme in surface modeling from a contour map is also tested.

AB - In this investigation, we propose a scheme which integrates the two complementary approaches, i.e., the raster approach and the vector approach, to minimize the number of feature points but still preserve the shape of digital curves with high fidelity. The raster form of the digital curve is first encoded in the Freeman chain code space. Then the second order derivative operator combined with a Gaussian filter is applied to detect zero crossings. The turning points on the curve detected as zero crossings in Freeman chain code space are then transformed to the image space. The second stage is then applying dynamic strip algorithm to further eliminate unnecessary points remaining in the first stage. In order to avoid over- elimination of the points, the maximum length of the strip may also be assigned in the scheme. To quantitatively analyze the performance of the proposed scheme, the perpendicular distance of each point on the original curve to the fitted line segment characterized by the dominant points is calculated. The applicability of the proposed scheme in surface modeling from a contour map is also tested.

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M3 - Conference contribution

AN - SCOPUS:0028755287

SN - 0819416967

T3 - Proceedings of SPIE - The International Society for Optical Engineering

SP - 109

EP - 115

BT - Proceedings of SPIE - The International Society for Optical Engineering

A2 - Ebner, Heinrich

A2 - Heipke, Christian

A2 - Eder, Konrad

T2 - ISPRS Commission III Symposium: Spatial Information from Digital Photogrammetry and Computer Vision

Y2 - 5 September 1994 through 9 September 1994

ER -