Abstract
High efficiency video coding (HEVC) is the newest video coding standard, which employs some advanced coding techniques as compared to the previous standard H.264. The flexible quad-tree partitioning of coding tree unit (CTU) and various candidate modes of prediction unit (PU) significantly promote the video compression efficiency; however, these techniques lead to a great amount of computational loads. In this paper, a fast mode decision algorithm for HEVC intra coding is proposed based on texture partition and direction. It consists of two sub-algorithms: the CTU depth range prediction (CDRP) and the intra-prediction mode selection (IPMS). The CDRP reduces the recursive partition number of coding unit (CU) based on the correlation between the CTU texture partition and the optimum CU partition, and it first calculates the texture partition flags of different-size CUs from bottom to top. Then, it employs these partition flags to predict the depth range of the current CTU and decide whether to terminate the CU partition in advance. In order to reduce the number of candidate PU modes for the Hadamard optimization, the IPMS first uses the three-step selection of the candidate modes. The first step selects the candidate modes based on the correlation between the texture directions and the optimum PU modes. The second step selects the candidate modes by using the best modes among the selected modes in the first step. The third step selects the candidate modes by using the spatial correlation of the optimum modes between the current PU and its adjacent PUs. Then, in order to reduce the number of candidate modes for the rate-distortion optimization, the IPMS utilizes the numerical relationship of the sorted Hadamard costs of above selected modes, the optimum modes of adjacent PUs and the statistical characteristics of the small-size PUs. Compared to the original algorithm in HEVC test model, the proposed overall algorithm can reduce 60% encoding time on average with only a 1.45% increase in Bjontegaard delta bit rate under the all-intra configuration. Compared to the most of state-of-the-art algorithms, the proposed overall algorithm has better computational performances and similar rate-distortion performances.
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References
Ohm, J.R., Sullivan, G.J., Schwarz, H., Tan, T.K., Wiegand, T.: Comparison of the coding efficiency of video coding standards—including high efficiency video coding (HEVC). IEEE Trans. Circuits Syst. Video Technol. 22(12), 1669–1684 (2012)
Sullivan, G.J., Ohm, J.R., Han, W.J., Wiegand, T.: Overview of the efficiency video coding (HEVC) standard. IEEE Trans. Circuits Syst. Video Technol. 22(12), 1649–1668 (2012)
Hu, N., Yang, E.H.: Fast mode selection for HEVC intra-frame coding with entropy coding refinement based on a transparent composite model. IEEE Trans. Circuits Syst. Video Technol. 25(9), 1521–1532 (2015)
Chen, Z.Y., Chang, P.C.: Rough mode cost-based fast intra coding for high-efficiency video coding. J. Vis. Commun. Image Represent. 43, 77–88 (2017)
Ruiz, D., Fernández-Escribano, G., Martínez, J.L., Cuenca, P.: A unified architecture for fast HEVC intra-prediction coding. J. Real-Time Image Process. 1–20 (2017)
Shang, X.W., Wang, G.Z., Fan, T., Li, Y.: Fast CU size decision and PU mode decision algorithm in HEVC intra coding. In: IEEE International Conference on Image Processing (ICIP), pp. 1593–1597 (2015)
Heindel, A., Pylinski, C., Kaup, A.: Two-stage exclusion of angular intra prediction modes for fast mode decision in HEVC. In: IEEE International Conference on Image Processing (ICIP), pp. 529–533 (2016)
Min, B., Cheung, R.C.C.: A fast CU size decision algorithm for the HEVC intra encoder. IEEE Trans. Circuits Syst. Video Technol. 25(5), 892–896 (2015)
Zhou, C., Zhou, F., Chen, Y.W.: Spatio-temporal correlation based fast coding unit depth decision for high efficiency video coding. J. Electron. Imaging 22(4), 6931–6946 (2013)
Ramezanpour, M., Zargari, F.: Fast HEVC I-frame coding based on strength of dominant direction of CUs. J. Real-Time Image Process. 12, 397–406 (2016)
Zhang, T., Sun, M.T., Zhao, D., Gao, W.: Fast intra-mode and CU size decision for HEVC. IEEE Trans. Circuits Syst. Video Technol. 27(8), 1714–1726 (2015)
Lim, K., Lee, J., Kim, S.: Fast PU skip and split termination algorithm for HEVC intra prediction. IEEE Trans. Circuits Syst. Video Technol. 25(8), 1335–1346 (2015)
Öztekin, A., Erçelebi, E.: An early split and skip algorithm for fast intra CU selection in HEVC. J. Real-Time Image Process. 12, 273–283 (2016)
Lu, X., Xiao, N., Martin, G., Hu, Y., Jin, X.: Fast intra coding implementation for high efficiency video coding (HEVC). In: Data Compression Conference (DCC), pp. 201–210 (2017)
Gu, J., Tang, M., Wen, J.: SATD based fast intra prediction for HEVC. In: Data Compression Conference (DCC), pp. 442–442 (2017)
Zhang, H., Ma, Z.: Fast intra mode decision for high efficiency video coding (HEVC). IEEE Trans. Circuits Syst. Video Technol. 24(4), 660–668 (2014)
Yang, M., Christos, C.: Fast intra encoding decisions for high efficiency video coding standard. J. Real-Time Image Process. 13, 797–806 (2017)
Sun, X., Chen, X., Xu, Y., Xiao, Y., Wang, Y.: Fast CU size and prediction mode decision algorithm for HEVC based on direction variance. J. Real-Time Image Process. 1–14 (2017)
Cho, S., Kim, M.: Fast CU splitting and pruning for suboptimal CU partitioning in HEVC intra coding. IEEE Trans. Circuits Syst. Video Technol. 23(4), 1555–1564 (2013)
Abdelrasoul, M., Sayed, M.S., Goulart, V.: Diagonal-based fast intra-mode decision algorithm for HEVC. IET Image Process. 11(10), 888–898 (2017)
Shen, L.Q., Liu, Z., Zhang, X.P., Zhao, W.Q., Zhang, Z.Y.: An effective CU size decision method for HEVC encoders. IEEE Trans. Multimedia 15(2), 465–470 (2013)
Zhang, J.L., Li, B., Li, H.: An efficient fast mode decision method for inter prediction in HEVC. IEEE Trans. Circuits Syst. Video Technol. 26(8), 1502–1515 (2016)
Zhang, J., Kwong, S., Wang, X.: Two-stage fast inter CU decision for HEVC based on bayesian method and conditional random fields. IEEE Trans. Circuits Syst. Video Technol. PP(99), 1–13 (2017)
Bossen, F.: Common test conditions and software reference configurations. In: ITU-T WP3/16 and ISO/IEC JTC1/SC29/WG11 12th Meeting, Geneva, pp. 1–3 (2013)
Bjontegaard, G.: Calculation of average PSNR differences between RD curves. In: Proceedings of the VCEG-M33, pp. 1–4 (2001)
Acknowledgments
This work was partly supported by the Natural Science Foundation of Zhejiang Province under Grant No. LY17F010013 and the National Natural Science Foundation of China under Grants Nos. 61401398, 61471150.
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Zhu, W., Yi, Y., Zhang, H. et al. Fast mode decision algorithm for HEVC intra coding based on texture partition and direction. J Real-Time Image Proc 17, 275–292 (2020). https://doi.org/10.1007/s11554-018-0766-z
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DOI: https://doi.org/10.1007/s11554-018-0766-z