In this paper, a novel and effective lip-based biometric identification approach with the Discrete HiddenMarkov
Model Kernel (DHMMK) is developed. Lips are described by shape features (both geometrical and sequential) on
two different grid layouts: rectangular and polar. These features are then specificallymodeled by a DHMMK, and
learnt by a support vector machine classifier. Our experiments are carried out in a ten-fold cross validation fashion
on three different datasets, GPDS-ULPGC Face Dataset, PIE Face Dataset and RaFD Face Dataset. Results show
that our approach has achieved an average classification accuracy of 99.8%, 97.13%, and 98.10%, using only two
training images per class, on these three datasets, respectively. Our comparative studies further show that the
DHMMK achieved a 53% improvement against the baseline HMM approach. The comparative ROC curves also
confirm the efficacy of the proposed lip contour based biometrics learned byDHMMK.We also showthat the performance
of linear and RBF SVM is comparable under the frame work of DHMMK.