—In this paper, a novel matting method is proposed
to automatically detect and separate foreground, background
and transitional (unknown) regions in a color image. In order
to detect the background color, K-means clustering in Y CbCr
color space is firstly used to classify the background colors
into a limited number of clusters. Then the spatial information
is further used to refine the background and minimize the
unknown regions. In this case, an image can be automatically
segmented into three hard regions: foreground, background
and unknown regions. For transitional (unknown) regions, the
alpha matting based on Wang’s robust matting algorithm is
utilized to refine the accuracy of the separation results. By
combining an automatical background determination metric and
Wang’s robust matting, the proposed matting method can handle
images with single-colored or gridded background. The required
user input is significantly simplified compared to conventional
alpha matting schemes which require users to provide a hard
image segmentation manually. The experimental results show that
improved matting results can be achieved for complex unknown
regions which contain semi-transparent materials or tiny objects
such as hair stripes.