RESUMO
In this paper, the definition of NURBS curve and a speed-controlled interpolation in which the feed rate is automatically adjusted in order to meet the specified chord error limit were discussed. Besides those, a definition of linear interpolation error of post-processed data was proposed, which should be paid more attention to because it will not only reduce quality of the surface but also may cause interference and other unexpected trouble. In order to control the error, a robust algorithm was proposed, which successfully met a desired error limit through interpolating some essential CL data. The excellence of the proposed algorithm, in terms of its reliability and self-adaptiveness, has been proved by simulation results.
RESUMO
Objective To investigate the Ring Artifact Location Algorithm based on edge detection to eliminate the ring artifact.Methods The Sobel operator was used to extract the ring edge,and then an algorithm,which combined scan line searching with line fitting,was applied to determining the ring center and its size.Finally the linear interpolation algorithm was used to get rid of the ring artifact.Results This method was very effective to eliminate the ring artifact of both phantom and clinical images.Conclusion This algorithm is faster and more effective than the usual one and its speed and accuracy are improved.