High dynamic range video with ghost removal

We propose a new method for ghost-free high dynamic range (HDR) video taken with a camera that captures alternating short and long exposures. These exposures may be combined using traditional HDR techniques, however motion in a dynamic scene will lead to ghosting artifacts. Due to occlusions and fast moving objects, a gradient-based optical flow motion compensation method will fail to eliminate all ghosting. As such, we perform simpler block-based motion estimation and refine the motion vectors in saturated regions using color similarity in the adjacent frames. The block-based search allows motion to be calculated directly between adjacent frames over a larger search range, yet at the cost of decreased motion fidelity. To address this, we investigate a new method to fix registration errors and block artifacts using a cross-bilateral filter to preserve the edges and structure of the original frame while retaining the HDR color information. Results show promising dynamic range expansion for videos with fast local motion.