Fourierdescriptors
Fourier descriptors are a method for representing the boundary of a planar shape by the discrete Fourier transform of its boundary coordinates. They are commonly applied to closed contours in image analysis and pattern recognition, providing a compact, quantitative description that can be used for shape matching, retrieval, and classification.
The typical workflow involves extracting a boundary from an image, resampling the boundary into N evenly spaced
To compare shapes across images, the descriptors are normalized to achieve invariance to translation, rotation, and
Elliptic Fourier Descriptors (EFD) are a popular variant that expresses the boundary as a sequence of ellipses