【摘要】：當(dāng)今信息化的時(shí)代,隨著計(jì)算機(jī)及互聯(lián)網(wǎng)技術(shù)的發(fā)展,視頻應(yīng)用越來(lái)越廣泛而頻繁。無(wú)線視頻傳輸是無(wú)線射頻收發(fā)和視頻信息處理技術(shù)的結(jié)合,適用于許多難以靠有線傳輸視頻的場(chǎng)合。當(dāng)今各領(lǐng)域各應(yīng)用場(chǎng)合對(duì)無(wú)線視頻傳輸提出了更高的需求,視頻分辨率和幀率的增大直接導(dǎo)致壓縮后的視頻碼率驟然上升。為實(shí)現(xiàn)視頻的及時(shí)傳送,在提升無(wú)線收發(fā)能力的同時(shí),采用新一代視頻壓縮標(biāo)準(zhǔn)HEVC能夠節(jié)約一半的碼率。為在無(wú)線視頻傳輸系統(tǒng)中應(yīng)用HEVC,需要解決其計(jì)算復(fù)雜度高的問(wèn)題。目前的基于HEVC的低復(fù)雜度幀內(nèi)幀間算法,一般針對(duì)的環(huán)節(jié)有限,雖然保證了率失真性能幾乎不變,但編碼時(shí)間的降低也比較有限。考慮到無(wú)線視頻傳輸?shù)膽?yīng)用實(shí)際,本文在略微犧牲率失真性能的情況下,節(jié)約了更多的編碼時(shí)間。基于對(duì)幀內(nèi)幀間視頻壓縮原理的理解和對(duì)最優(yōu)率失真算法流程的研究,本文對(duì)幀內(nèi)幀間的CU劃分環(huán)節(jié)和模式預(yù)測(cè)環(huán)節(jié)都進(jìn)行了低復(fù)雜度改進(jìn)。本文首先提出了基于圖像空間相關(guān)性的CU快速劃分算法,利用相鄰CU的深度信息為當(dāng)前CU設(shè)定深度范圍,該算法可以同時(shí)應(yīng)用于幀內(nèi)預(yù)測(cè)與幀間預(yù)測(cè)的情形。對(duì)于幀內(nèi)預(yù)測(cè),本文首先根據(jù)參考像素方差和幀內(nèi)模式之間的統(tǒng)計(jì)規(guī)律,提出了可以跳過(guò)RMD過(guò)程并排除角度模式的快速算法。在RMD與RDO模式選擇過(guò)程中,本文利用圖像紋理特征以及MPM統(tǒng)計(jì)特征實(shí)現(xiàn)了幀內(nèi)模式的快速優(yōu)選。接著利用幀內(nèi)最終預(yù)測(cè)模式的RD代價(jià)實(shí)現(xiàn)了CU劃分的提前終止,最后結(jié)合上述各改進(jìn)點(diǎn)設(shè)計(jì)了低復(fù)雜度幀內(nèi)預(yù)測(cè)綜合算法。對(duì)于幀間預(yù)測(cè),本文基于對(duì)率失真代價(jià)與預(yù)測(cè)殘差及量化參數(shù)的理解,認(rèn)為當(dāng)滿足Skip條件或CBF為零的條件時(shí),為實(shí)現(xiàn)更高的編碼時(shí)間節(jié)約比率,可以不加約束地跳過(guò)后續(xù)其他模式。另外,考慮到非對(duì)稱分割模式(AMP)起到的作用較小,本文禁用了非對(duì)稱模式。最后結(jié)合上述幀間預(yù)測(cè)策略及CU快速劃分算法,設(shè)計(jì)了低復(fù)雜度幀間預(yù)測(cè)綜合算法。實(shí)驗(yàn)表明,相對(duì)于現(xiàn)有低復(fù)雜度算法,本文提出的幀內(nèi)幀間綜合算法,在率失真性能損失略微提升的前提下,可以降低更多的編碼時(shí)間。
[Abstract]:Nowadays, with the development of computer and Internet technology, video application is more and more extensive and frequent. Wireless video transmission is a combination of radio frequency transceiver and video information processing technology, which is suitable for many occasions where it is difficult to transmit video by cable. Nowadays, there is a higher demand for wireless video transmission in various fields. The increase of video resolution and frame rate directly leads to the sudden increase of video rate after compression. In order to realize the timely transmission of video, the new generation video compression standard HEVC can save half the bit rate while improving the wireless transceiver ability. In order to apply HEVC, in wireless video transmission system, it is necessary to solve the problem of high computational complexity. The current low complexity intra-frame algorithm based on HEVC is generally limited. Although the rate-distortion performance is almost unchanged, the reduction of coding time is also limited. Considering the application practice of wireless video transmission, this paper saves more coding time under the condition of slightly sacrificing rate-distortion performance. Based on the understanding of the principle of intra-frame video compression and the research of the optimal rate-distortion algorithm, this paper improves the CU partition and mode prediction of intra-frame frames with low complexity. In this paper, a fast CU partition algorithm based on image spatial correlation is proposed. Using the depth information of adjacent CU to set the depth range for the current CU, the algorithm can be applied to both intra-frame prediction and inter-frame prediction. For intra prediction, according to the statistical law between reference pixel variance and intra mode, a fast algorithm which can skip RMD process and exclude angle mode is proposed in this paper. In the process of RMD and RDO mode selection, this paper uses image texture features and MPM statistical features to achieve fast intra mode selection. Then the early termination of CU partition is realized by using the RD cost of the final intra prediction mode. Finally, a low complexity intra prediction synthesis algorithm is designed according to the above improved points. For inter-frame prediction, based on the understanding of rate-distortion cost, prediction residual and quantification parameters, it is considered that when the Skip condition or CBF is zero, in order to achieve a higher coding time saving ratio, the following other modes can be skipped without constraint. In addition, considering that asymmetric segmentation mode (AMP) plays a small role, asymmetric mode is disabled in this paper. Finally, combined with the above inter-frame prediction strategy and CU fast partition algorithm, a low complexity inter-frame prediction synthesis algorithm is designed. The experimental results show that compared with the existing low complexity algorithms, the intra-frame synthesis algorithm proposed in this paper can reduce the coding time with the slight improvement of rate-distortion performance loss.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TN919.81

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 郭奕星;;下一代數(shù)字視頻技術(shù)應(yīng)用前瞻[J];電信快報(bào);2014年08期

相關(guān)博士學(xué)位論文 前1條

1 王建富;H.265/HEVC編碼加速算法研究[D];中國(guó)科學(xué)技術(shù)大學(xué);2015年

相關(guān)碩士學(xué)位論文 前2條

1 蔣亮;基于ARM的無(wú)線圖像傳輸系統(tǒng)設(shè)計(jì)[D];電子科技大學(xué);2013年

2 安中文;一種無(wú)線圖像傳輸系統(tǒng)設(shè)計(jì)方案[D];北京郵電大學(xué);2013年

，

本文編號(hào)：2507868