本文關(guān)鍵詞： HEVC 像素梯度 幀內(nèi)預(yù)測　出處：《電子科技大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著互聯(lián)網(wǎng)技術(shù)的發(fā)展,越來越多的人使用智能手機(jī)、平板電腦觀看在線高清視頻。同時(shí),超高清視頻技術(shù)正逐步興起。在線高清視頻流給網(wǎng)絡(luò)設(shè)備造成了沉重的負(fù)擔(dān),而目前主流的H.264視頻編碼標(biāo)準(zhǔn)對高清、超高清的壓縮性能較低。為進(jìn)一步降低視頻編碼后碼率,提高對高清、超高清視頻的壓縮性能,JCT-VC組織制定了新一代視頻編碼標(biāo)準(zhǔn)HEVC。HEVC基于H.264中的混合視頻編碼框架,引入了靈活單元?jiǎng)澐帧⒏泳?xì)的幀內(nèi)預(yù)測、環(huán)內(nèi)去塊濾波等技術(shù)。但是靈活的單元?jiǎng)澐趾透泳?xì)的幀內(nèi)預(yù)測技術(shù)給HEVC幀內(nèi)編碼帶來了更高的計(jì)算復(fù)雜度,因此如何有效減少幀內(nèi)編碼時(shí)間,已經(jīng)成為HEVC算法研究中的一個(gè)研究熱點(diǎn)。文中利用像素點(diǎn)的梯度信息,改進(jìn)了HEVC幀內(nèi)預(yù)測算法,并使用C++語言進(jìn)行算法的實(shí)現(xiàn),最后給出了算法性能分析結(jié)果。具體內(nèi)容如下:首先,研究了HEVC基本編碼結(jié)構(gòu)及其幀內(nèi)預(yù)測關(guān)鍵技術(shù),并同H.264幀內(nèi)編碼技術(shù)進(jìn)行了對比分析。其次,研究分析H.264、HEVC幀內(nèi)預(yù)測算法,重點(diǎn)分析了H.264中基于圖像紋理特征的幀內(nèi)預(yù)測算法和HEVC粗選擇幀內(nèi)預(yù)測算法。在此基礎(chǔ)上,使用像素梯度信息,改進(jìn)了粗選擇幀內(nèi)預(yù)測算法,并使用C++語言實(shí)現(xiàn)該算法。最后,使用HEVC測試視頻,在全幀內(nèi)、低復(fù)雜度編碼模式下,對像素梯度幀內(nèi)預(yù)測算法和粗選擇算法進(jìn)行對比測試。測試結(jié)果表明,像素梯度幀內(nèi)預(yù)測算法在相同圖像質(zhì)量的情況下,碼率平均增加1.62%,編碼時(shí)間平均減少22.50%,證明算法有效可行。像素梯度幀內(nèi)預(yù)測算法對粗選擇幀內(nèi)預(yù)測算法進(jìn)行了改進(jìn),有效減少了幀內(nèi)預(yù)測編碼時(shí)間,具有一定的理論意義與實(shí)踐價(jià)值。
[Abstract]:With the development of Internet technology, more and more people use smart phones and tablets to watch online HD video. Meanwhile, UHD video technology is gradually rising. However, the current mainstream H.264 video coding standard has low compression performance for high-definition and ultra-high-definition video. In order to further reduce the rate of video coding and improve the high-definition, High definition Video Compression performance JCT-VC organizes and formulates a new generation of video coding standard HEVC.HEVC based on H.264 hybrid video coding framework, introduces flexible unit partitioning, more refined intra prediction, However, flexible unit partition and finer intra prediction technology bring higher computational complexity to HEVC intra coding, so how to reduce the intra coding time effectively. In this paper, the gradient information of pixel points is used to improve the HEVC intra prediction algorithm, and C language is used to implement the algorithm. Finally, the performance analysis results of the algorithm are given. The main contents are as follows: firstly, the basic coding structure of HEVC and the key techniques of intra prediction are studied, and compared with H.264 intra coding. Secondly, the intra prediction algorithm of H.264 and HEVC is studied and analyzed. The intra prediction algorithm based on image texture feature and the HEVC coarse selection intra prediction algorithm in H.264 are analyzed. Based on this, the coarse selection intra prediction algorithm is improved by using pixel gradient information, and the algorithm is implemented in C language. The HEVC test video is used to compare the pixel gradient intra prediction algorithm with the coarse selection algorithm in the full frame and low complexity coding mode. The test results show that the pixel gradient intra prediction algorithm is of the same image quality. The average bit rate increases by 1.62bit rate and the coding time decreases by 22.50. it is proved that the algorithm is effective and feasible. The pixel gradient intra prediction algorithm improves the coarse selection intra prediction algorithm and effectively reduces the intra prediction coding time. It has certain theoretical significance and practical value.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN919.81
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本文編號：1520343