Classification of gait types based on the duty-factor

This paper deals with classification of human gait types based on the notion that different gait types are in fact different types of locomotion, i.e., running is not simply walking done faster. We present the duty-factor, which is a descriptor based on this notion. The duty-factor is independent on the speed of the human, the cameras setup etc. and hence a robust descriptor for gait classification. The duty-factor is basically a matter of measuring the ground support of the feet with respect to the stride. We estimate this by comparing the incoming silhouettes to a database of silhouettes with known ground support. Silhouettes are extracted using the codebook method and represented using shape contexts. The matching with database silhouettes is done using the Hungarian method. While manually estimated duty-factors show a clear classification the presented system contains misclassifications due to silhouette noise and ambiguities in the database silhouettes.