A fast CU depth decision mechanism for HEVC

• HEVC requires a high computational complexity.
• The RD cost calculations outside the adaptive CU depth range are skipped.
• The RD cost calculations at the current CU depth are further skipped.
• The computational complexity of HEVC is reduced by about 16% on average.
• The proposed mechanism still maintains high video quality.

In order to reduce the computational complexity of High Efficiency Video Coding (HEVC), a fast Coding Unit (CU) depth decision mechanism is proposed by utilizing the spacial correlations in the sequence frame. The proposed mechanism includes an adaptive CU depth range determination and a CU depth comparison algorithm. CU depth range is determined according to the distribution of CU depths in the same sequence. Thus, the Rate Distortion (RD) cost calculations at the CU depths outside of the range can be skipped. Furthermore, by comparing the depths of neighbor CUs with the current CU depth, the RD cost calculations at the current CU depth may be further skipped. Experimental results show that the proposed mechanism achieves a significant reduction of the computational complexity by comparing with the original HEVC, while still maintaining high video quality.