Temporal trimap propagation using motion-assisted shape blending

In digital matting, the availability of an accurate trimap is essential for pulling an accurate matte. This requirement becomes all the more critical in video matting where temporal coherence of the trimap is an added requirement. However, the task of manually drawing a trimap for every frame is not feasible. This paper proposes an adaptive trimap propagation framework that alleviates this task by automatically generating trimaps between two key-frames. 2-D shape blending is coupled with motion flow using a novel strategy based on angle criteria to generate accurate in-between foreground contours for the entire video sequence. A robust trimap generation step ensures temporal coherence between the contours. Quantitative and qualitative comparisons on complex video sequences demonstrates the effectiveness of the proposed method.