Robust lip contour extraction using separability of multi-dimensional distributions

We present a lip contour extraction method using separability of color intensity distributions. Usually it is difficult to robustly extract the outer lip contour mainly because of the following two problems. First, the outer lip contour is often blurred. Secondly, the contrast between the skin and the lip region is often reduced by transformation from the color intensity to the gray scale intensity. To overcome these two problems we propose an edge detection method in which edge strength is defined as separability of two color intensity distributions. We apply the proposed method to lip contour extraction using an active contour model. We present several experimental results demonstrating the effectiveness of the proposed method.