1 3 42 5 a11 a44 a55 a22 a33 a12 a45a34a23 Forehead Eyes Nose Mouth Chin forehead eyes nose mouth chin forehead eyes nose mouth chin forehead eyes nose mouth chin O O O O i, j i+m, j i, j+n i+m, j+n Prototype HMM Uniform Segmentation Initialize Parameters Segmental K Means Convergence NO YES Embedded Viterbi Segmentation Estimated HMM 1D Viterbi 1D Viterbi 1D Viterbi 1D Viterbi 1D Viterbi 1D Viterbi 1D Viterbi O1,1 O O O P(O, Q| Λ) λ λ λ (1) (N0) λ λ λ (1) (2) (N0) (2) 1, T 1 1T 0, 1 T 0, T ( Π A0 )0, . i+m, j i, j+n i+m, j+n Prototype HMM Uniform Segmentation Initialize Parameters Segmental K Means Convergence NO YES Embedded Viterbi Segmentation Estimated HMM 1D Viterbi 1D Viterbi 1D Viterbi 1D