A residuals-distribution-guided local optimization approach to B-spline fitting in capturing image outlines

Abstract

The B-spline technique is attractive to fit complex image outlines because of its freeform character. However, knot placement remains a difficult task. In this paper, the knots optimization problem is converted to an issue of feature points optimization, and a residuals-distribution-guided local optimization (RDG-LO) method is proposed to promote the quality of fitted curves. The RDG-LO algorithm states the moving direction and distance of candidate feature points according to the distribution of residuals. For a fixed number of feature points, the accuracy of the fitted curve is improved by adjusting the positions of feature points and the length of the fitted curve. Experimental results show that the fitted curve after optimization possesses advantages in both accuracy and simplicity. This algorithm is of great significance in the three-dimensional digital reconstruction of biomedical images.