Stereoscopic chroma key matting using statistical analysis in CIECAM02 color space

In a chroma keying system, the foreground objects are recorded in front of background with solid color, which is used as side information to efficiently and accurately separate the foreground from the background. Although the technique of chroma keying has been widely used for decades, there is little work on its application to stereoscopic images/videos in either industry or academia fields. We propose a new chroma key matting method to generate high quality matting results. Specifically, the colors of foreground objects to be chroma keyed are histogram analysed in CIECAM02 color space, which can provide better hue/saturation consistency compared to previous human visual system (HVS) based color spaces such as HSV, CIELab and IPT. The color of background region, which is occluded by foreground objects, is estimated by spatial affinity. With the estimated foreground/background color for each pixel, the foreground objects can be accurately extracted along with its transparency map α. By doing this, we can generate depth map with accurate and sharp boundary, which is essential for post 3D processing such as depth image based rendering (DIBR).