Variable silhouette energy image representations for recognizing human actions

Recognizing human actions is an important topic in the computer vision community. One of the challenges of recognizing human actions is describing for the variability that arises when arbitrary view camera captures human performing actions. In this paper, we propose a spatio-temporal silhouette representation, called silhouette energy image (SEI), and multiple variability action models, to characterize motion and shape properties for automatic recognition of human actions in daily life. To address the variability in the recognition of human actions, several parameters, such as anthropometry of the person, speed of the action, phase (starting and ending state of an action), camera observations (distance from camera, slanting motion, and rotation of human body), and view variations are proposed. We construct the variability (or adaptable) models based on SEI and the proposed parameters. Global motion descriptors express the spatio-temporal properties of combined energy templates (SEI and variability action models). Our construction of the optimal model for each action and view is based on the support vectors of global motion descriptions of action models. We recognize different daily human actions of different styles successfully in the indoor and outdoor environment. Our experimental results show that the proposed method of human action recognition is robust, flexible and efficient.