Fast gradient-domain video compositing using hierarchical data structure

We present a fast gradient domain video compositing using hierarchical data structure which subdivides the compositing region into an octree data. To handle large video compositing by solving a 3D Poisson equation, the derived linear system is usually large. To solve the system requires large memory space and long computational time, which makes it intractable on a standard computer. To address the scalability problem, rather than compositing the video in the gradient-domain pixel by pixel, we perform the video compositing in a reduced space using octree data structure, which significantly reduces the variables. We show that the proposed octree approach is efficient in both seamless and mixing gradient-domain video compositing. Our method enables to perform video compositing in greatly reduced computational time and memory space, while receiving visually identical results with that computed from the full solution.