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Face Detection and Modeling for Recognition - Biometrics Research ...

Face Detection and Modeling for Recognition - Biometrics Research ...

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E comp<br />

eye = E msat + E csh + E cdif , (5.12)<br />

(<br />

E msat = [ (R − K 3 )2 + (G − K 3 )2 + (B − K 3 )2<br />

) 0.5<br />

(R + G + B − K)2<br />

− ],<br />

3<br />

(5.13)<br />

E csh = [[Cr − K/2] 2 − [Cb − K/2] 2 ], (5.14)<br />

E cdif = [[Cr] − [Cb]], (5.15)<br />

where E msat is the modified saturation (that is the distance in the plane between<br />

a point (R, G, B) <strong>and</strong> (K/3, K/3, K/3)) where R + G + B = K, E csh<br />

is chroma<br />

shift, E cdif is chroma difference, K = 256 is the number of grayscales <strong>for</strong> each color<br />

component, <strong>and</strong> [x] indicates a function that normalizes x into the interval [0, 1]. The<br />

eye component energies <strong>for</strong> subjects in Fig. 5.11(a) is shown in Fig. 5.11(b). The<br />

(a) (b) (c) (d) (e)<br />

Figure 5.11. Component energy (darker pixels have stronger energy): (a) face region<br />

of interest; (b) eye component energy; (c) mouth component energy; (d) nose<br />

boundary energy; (e) nose boundary energy shown as a 3D mesh surface.<br />

mouth component energy is computed as E comp<br />

mouth<br />

126<br />

= [−[Cb] − [Cr]]. Figure 5.11(c)

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