Improvement of normality and orthogonality in HEVC transform bases

The present paper provides transform bases with improved normality and orthogonality properties based on the integer DCT of high-efficiency video coding (HEVC). The proposed transform bases improve the normality and orthogonality properties compared to the HEVC transform bases. Coding and re-encoding experiments were conducted using HEVC test model (HM) version 6.0 and the proposed method. The experiments were conducted under various bitrate ranges. Under the high-bit-rate condition, the proposed method exhibited coding gains compared to HM 6.0 without increasing the encoding/decoding time.