Highly Scalable Coding of Depth Maps with Arc Breakpoints

Recent work highlights the importance of incorporating geometry information into the compression of depth maps. For many applications, features such as resolution scalability and embedded coding are also highly desirable. JPEG 2000 offers these scalability features but suffers from poor compression performance in the vicinity of strong discontinuities. We propose a novel compression strategy for depth maps that incorporates geometry information while retaining the highly scalable coding properties of JPEG 2000. Our scheme involves two separate image pyramid structures, one for arc breakpoints and other for sub-band samples produced by a breakpoint-adaptive transform. Breakpoints capture geometric attributes and are also amenable to scalable coding. We develop an R-D optimization framework for the breakpoint data. We also use a variation of the EBCOT scheme to produce embedded bit-streams for both the breakpoint and sub-band data, allowing them to be independently and incrementally sequenced based on R-D considerations.