Human face recognition by P-type Fourier descriptor

A new Chebyshev polynomials descriptor applicable to open curves

“…A Chebyshev polynomial P m (t) is a polynomial in t of degree m, defined as P m (t) = cos(m arccos(t )) (1) Clearly, the range of variable t is the interval [−1, 1]. That is, Chebyshev polynomials are polynomials defined on the interval [−1, 1].…”

“…Let t = cos(θ ), and then we can obtain P m (t) = cos(mθ ). According to trigonometric identity cos mθ + cos(m − 2) θ = 2 cos θ cos(m − 1)θ , the definition of Chebyshev polynomial (1) can be rewritten with recurrence relation as follows…”

“…For instance, in elliptic Fourier descriptor [4], the reconstructed curve tends to become a closed curve and to vibrate near the endpoints. In order to efficiently represent open curves, the P-type Fourier descriptor [13] was proposed and has been successfully applied to recognition of shape of human face profiles [1], statistical shape analysis of rice leaf [17] and tracing open curves [14]. However, this method is sensitive ✩ This paper has been recommended for acceptance by A. Koleshnikov.…”

Human face profile recognition by a P-Fourier descriptor

“…(8) 1pQ 3 Extraction of Profile Outline Profiles of 130 subjects were photographed by a video camera in natural light, with a gray wall in the background. A subject sitting on a fixed chair was asked to comb his or her hair back, or use a hair band, and to look at a sign in front of him/her.…”