Implicit transform unit partitioning in HEVC

Variable TU size is one of the key contributors to significant coding improvements in HEVC over traditional video coding standards. Residual quadtree is employed in HEVC to allow flexibility in TU partitioning while minimizing overhead bits. Flexibility in TU size also increases complexity in encoder dramatically. This paper described implicit transform unit partitioning which is employed in HEVC to reduce complexity in encoder while maintaining coding performance. Simulation results are also reported in this paper to validate coding performance of implicit TU partitioning.