CORE TRANSFORM DESIGN FOR HIGH EFFICIENCY VIDEO CODING (HEVC)

Transcription

1 CORE TRANSFORM DESIGN FOR HIGH EFFICIENCY VIDEO CODING (HEVC) Jie Dong, Yan Ye InterDigital Communications, LLC. Aug. 4 InterDigital, Inc. All rights reserved.

2 Core Transform in HEVC HEVC High Efficienc Video Coding Emerging video coding standard developed b JCTVC of ITUT/VCEG and ISO/IEC/MPEG. Focused on HD and ultra HD videos Coding unit size up to K K (K set in SPS) Transform size scaled accordingl 6 6 and 3 3 for large homogeneous regions 4 4 and for detailrich regions Highl desired features in integer transform design High energ compaction capabilit Equal L norms of basis vectors Orthogonal Fleibilit in implementation (matri multiplication and fast algorithm) 6bit integer arithmetic InterDigital, Inc. All rights reserved.

3 Factorizable Transform Matrices EvenOdd Part Decomposition OrderN DCT matri Proposed ordern integer transform matri 3 InterDigital, Inc. All rights reserved.

4 Factorizable Transform Matrices (Order) Odd Part of Order DCT Elements magnitudes [] C. Loeffler, A. Ligtenberg, and G. S. Moschtz, Practical fast D DCT algorithms with multiplications, in Proc. IEEE Int. Conf. Acoust. Speech Signal Process., vol.. Ma 99, pp InterDigital, Inc. All rights reserved.

5 Factorizable Transform Matrices (Order) Odd part of the Proposed Order Integer Transform Elements Relation. and. a 3. and InterDigital, Inc. All rights reserved.

6 Factorizable Transform Matrices (Order6) Odd Part of Order6 DCT 6 InterDigital, Inc. All rights reserved.

7 InterDigital, Inc. All rights reserved. Factorizable Transform Matrices (Order6) Odd part of the Proposed Order6 Integer Transform Elements Relation. a. b d e f c b g h a a h g b c f e d l l j i i j k k j i i j l l

8 Factorizable Transform Matrices (Order3) Odd Part of Order3 DCT Factorization proposed b Chen et al. cause high latenc Odd Part of the Proposed Order3 Integer Transform approimate are binar matrices and the same as approimate [] W. H. Chen, C. H. Smith, and S. C. Fralick, A fast computational algorithm for the discrete cosine transform, IEEE Trans. Commun., vol., no. 9, pp.49, Sept. 9. InterDigital, Inc. All rights reserved.

9 9 InterDigital, Inc. All rights reserved. Factorizable Transform Matrices (Order3) Elements Relation 3.. M 3 M

10 Factorizable Transform Matrices (Order3) Odd Part of the Proposed Order3 Integer Transform are binar matrices with onl one nonzero element in each row/column, used for reordering. is the onl effective matri in. InterDigital, Inc. All rights reserved.

11 Core Transform Design Proposed for HEVC Use the proposed general transform matrices Bruteforce search for the matri elements based on Element relations Almost equal L norms of the basis vectors Negligible deviation from DCT [3] Negligible transform error introduced b nonorthogonalit [4] Order4 6 Order Order Order S N 4 [3] M. Wien and S. Sun, ICT comparison for adaptive block transforms, document VCEGL, ITUT SG6/Q6, Jan.. [4] J. Dong, K. N. Ngan, C. K. Fong, and W. K. Cham, D order6 integer transforms for HD video coding, IEEE Trans. Circuits Sst. Video Technol., vol. 9, no., pp , Oct. 9. InterDigital, Inc. All rights reserved.

12 Core Transform Design Proposed for HEVC n << << << n << << << n << << 6 6 n 3 << << 3 44 n 4 >> << n << n 6 << n >> << 46 n 39 n 9 3 n 4 n 6 n 6 n n 4 n n 3 3 X n 3 3 n 9 X n n X 3 n 6 3 n X 4 3 n 4 n 3 3 n 3 n n n 9 n n 3 n 6 3 InterDigital, Inc. All rights reserved. << << << << << << << << << << << << << << << << u u u 6 u 4 u 4 u u u u u u 4 u 3 u u u 6 u 6 u u 3 u 9 u 3 u u u 3 u 9 u 9 u 3 u u u u u u

13 Eperimental Results Integrated into HM4. using 6bit integer arithmetic Tested under common test condition for and special test condition of CE Compared with other core transform designs in CE RateDistortion Performance: less than % BDrate difference under various test settings and QPs [] A. Fuldseth, G. Bjøntegaard, and M. Budagavi, CE: core transform design for HEVC, document JCTVCG49, Joint Collaborative Team on Video Coding, Nov.. [6] R. Joshi, J. Sole, and M. Karczewicz, CE: Scaled integer transforms supporting recursive factorization structure, document JCTVC G9, Joint Collaborative Team on Video Coding, Nov.. [] E. Alshina et al., CE: full factorization core transforms for HEVC, document JCTVCG3, Joint Collaborative Team on Video Coding, Nov.. 3 InterDigital, Inc. All rights reserved.

14 Eperimental Results Features offered b each core transform design Small DCT distortion Full factorization No scaling process Negligible transform error Fleible implementation Cisco s Qualcomm s Samsung s Proposed Numbers of arithmetic operations for Npoint D transform 4point point 6point 3point 4 InterDigital, Inc. All rights reserved. Cisco s Qualcomm s Samsung s Proposed

15 Conclusion Propose the core transform design for HEVC Factorizable general transform matrices Matri elements Features offered High energ compaction capabilit No scaling process Negligible transform error introduced b nonorthogonalit Fleible implementations 6bit integer arithmetic RD performance Less than % BDrate difference under various test settings InterDigital, Inc. All rights reserved.