Module imagingbook.common
Package imagingbook.common.geometry.fitting.circle.algebraic

Class CircleFitKasaA

java.lang.Object
imagingbook.common.geometry.fitting.circle.algebraic.CircleFitKasaA
All Implemented Interfaces:
CircleFitAlgebraic
public class CircleFitKasaA extends Object implements CircleFitAlgebraic

This is an implementation of the algebraic circle fitting algorithm described in [1]. This algorithm is among the oldest and simplest algebraic circle fitting methods. This implementation closely follows the original paper. The only difference is the use of a numerical solver (as compared to using the inverse of matrix M) for solving the 3x3 linear system.

Its performance is sufficient if points are sampled over a large part of the circle. It shows significant bias (estimated circles are too small) when sample points are confined to a small segment of the circle. It fails when matrix M becomes singular. Fits to exactly 3 (non-collinear) points are handled properly. Data centering is used to improve numerical stability (alternatively, a reference point can be specified).

[1] I. Kåsa. "A circle fitting procedure and its error analysis", IEEE Transactions on Instrumentation and Measurement 25(1), 8–14 (1976).

  • Constructor Details

    • CircleFitKasaA

      public CircleFitKasaA(Pnt2d[] points)
      Constructor. The centroid of the sample points is used as the reference point.
      Parameters:
      points - sample points

    • CircleFitKasaA

      public CircleFitKasaA(Pnt2d[] points, Pnt2d xref)
      Constructor. The centroid of the sample points is used as the reference point for data centering if null is passed for xref.
      Parameters:
      points - sample points
      xref - reference point or null

  • Method Details