2016 | OriginalPaper | Buchkapitel
Fourier Shape Descriptors
Fourier descriptors are an interesting method for modeling 2D shapes that are described as closed contours. Unlike polylines or splines, which are explicit and local descriptions of the contour, Fourier descriptors are global shape representations, that is, each component stands for a particular characteristic of the entire shape. If one component is changed, the whole shape will change. The advantage is that it is possible to capture coarse shape properties with only a few numeric values, and the level of detail can be increased (or decreased) by adding (or removing) descriptor elements. In the following, we describe what is called “cartesian” (or “elliptical”) Fourier descriptors, how they can be used to model the shape of closed 2D contours and how they can be adapted to compare shapes in a translation-, scale-, and rotation-invariant fashion.
