Hybrid key: An automatic tool for real-time high quality chroma keying

We present Hybrid Key, an automatic tool using chromatic information as the key signal for compositing multiple video layers together. This tool is based on our recently proposed chroma-keying mechanism which simulates human perception by utilizing a hybrid color space and reaches the minimum criteria of real-time high-definition video processing [1]. In this paper, we improve the quality of our perception-based algorithm, and optimized the implementation with a hybrid GPU/CPU architecture. Our new system introduces the task prioritizing and asynchronous processing without jeopardizing the quality. It efficiently distributes computational burdens between different processing units and therefore leaving more room for final alpha and foreground estimation as well as the newly added alpha optimization. In addition, our implementation can make use of GPU specified optimizations to further improve its efficiency. These advantages not only ensure the best overall quality in comparison to other state-of-the-art chroma keyers, but also provide a cost-efficient real-time 4K high-definition chroma keying solution and create the first iPad/iPhone application for high definition chroma keying on the go.