Crate efd

EFD Rust Library

Elliptical Fourier Descriptor (EFD) implementation in Rust. This crate implements 1D/2D/3D EFD and its related functions.

Keyword Alias:

• Elliptical Fourier Analysis (EFA)
• Elliptical Fourier Function (EFF)

Example of re-describing a new closed curve:

let curve = vec![
    [0., 0.],
    [1., 1.],
    [2., 2.],
    [3., 3.],
    [2., 2.],
    [1., 1.],
];
assert!(efd::util::valid_curve(&curve).is_some());
let described_curve = efd::Efd2::from_curve(curve, false).generate(20);

Example Images

2D and 3D closed curve:

2D and 3D open curve:

Posed EFD combined a curve with a pose (unit vectors) to describe the orientation of each point.

2D open curve and its full reconstruction:

Citations

Original

• Kuhl, FP and Giardina, CR (1982). Elliptic Fourier features of a closed contour. Computer graphics and image processing, 18(3), 236-258. https://doi.org/10.1016/0146-664X(82)90034-X

My Applications

• Chang, Y., Chang, JL., Lee, JJ. (2024). Atlas-Based Path Synthesis of Planar Four-Bar Linkages Using Elliptical Fourier Descriptors. In: Okada, M. (eds) Advances in Mechanism and Machine Science. IFToMM WC 2023. Mechanisms and Machine Science, vol 149. Springer, Cham. https://doi.org/10.1007/978-3-031-45709-8_20

Features

This crate supports no-std solution. Disable the “std” feature will enable it.

default-features = false

Re-exports

• pub extern crate nalgebra as na;

Modules

• util
  Utility functions for the library.

Structs

• Efd
  Elliptical Fourier Descriptor coefficients. Provide transformation between discrete points and coefficients.
• GeoVar
  Geometric variables.
• PosedEfd
  A shape with a pose described by EFD.

Enums

• U
  EFD dimension marker.

Traits

• Curve
  Copy-on-write curve type.
• Distance
  Be able to calculate the distance between two instances.
• EfdDim
  Trait for the dimension U<D> of EFD.
• RotHint
  Rotation hint for GeoVar.

Functions

• get_target_pos
  Get the theta value of each point coordinate of the curve.

Type Aliases

• Coeffs
  Coefficients type.
• Coeffs1
  1D Coefficients type.
• Coeffs2
  2D Coefficients type.
• Coeffs3
  3D Coefficients type.
• Coord
  Coordinate type of the dimension D.
• Efd1
  A 1D shape described by EFD.
• Efd2
  A 2D shape described by EFD.
• Efd3
  A 3D shape described by EFD.
• GeoVar1
  1D geometric type.
• GeoVar2
  2D geometric type.
• GeoVar3
  3D geometric type.
• Kernel
  An owned matrix of specific coefficients. (Dx2)
• PosedEfd1
  A 1D shape with a pose described by EFD.
• PosedEfd2
  A 2D shape with a pose described by EFD.
• PosedEfd3
  A 3D shape with a pose described by EFD.
• Rot
  Rotation type of the EFD.