3.1 AUs, FSs with description, and associated landmarks for each FS grouped into five categories........................ 24 3.2 Analysis of LC and VL features and polynomial interpolation order. 32 3.3 LC-VL Feature Improvements based on AU Combinations for CK+. 33 3.4 LC-VL Feature Improvements based on AU Combinations for MUG. 33 3.5 CK+ dataset Classification results for seven and six emotions denoted as A (Anger), D (Disgust), F (Fear), H (Happiness), Su (Surprise), S (Sadness) and N (Neutral) with accuracy in%............. 36 3.6 MUG dataset Classification results for seven and six emotions denoted as A (Anger), D (Disgust), F (Fear), H (Happiness), Su (Surprise), S (Sadness) and N (Neutral) with accuracy in%............. 36 iv