Real-time skin color detection under rapidly changing illumination conditions

Skin color provides a useful cue for vision based human-computer interaction (HCI). However, rapidly changing illumination conditions under HCI application environment make skin color detection a challenging task, as skin colors in an image highly depend on the illumination under which the image was taken. This paper presents a method for skin color detection under rapidly changing illumination conditions. Skin colors are modeled under the Bayesian decision framework. Face detection is employed to online sample skin colors and a dynamic thresholding technique is used to update the skin color model. When there is no face detected, color correction strategy is employed to convert the colors of the current frame to those as they appear under the same illuminant of the last model updated frame. Skin color detection is then applied on the color corrected image. Face detection is time-consuming and hence should not be applied to every frame in real-time applications on general consumer hardware. To improve efficiency, a novel method is proposed to detect illumination changes, and face detection is used to update the skin color model only if the illumination has changed. Experimental results show that the proposed method can achieve satisfactory performance for skin color detection under rapidly changing illumination conditions in real-time on general consumer hardware.