本文選題：HEVC + 屏幕內(nèi)容��； 參考：《北方工業(yè)大學(xué)》2017年碩士論文

【摘要】：屏幕內(nèi)容圖像或視頻廣泛應(yīng)用于視頻會(huì)議、遠(yuǎn)程桌面控制、無線顯示等設(shè)備中。與照相機(jī)捕捉的自然內(nèi)容不同,屏幕內(nèi)容通常包含大量的文本、圖表以及人造內(nèi)容,傳統(tǒng)的視頻編碼工具不能很有效地壓縮。為此,聯(lián)合視頻編碼工作組(Joint Collaborative Team on Video Coding,JCT-VC)致力于開發(fā)高效視頻編碼(High-efficiency video coding,HEVC)標(biāo)準(zhǔn)的屏幕內(nèi)容擴(kuò)展工具,例如幀內(nèi)塊拷貝模式、調(diào)色板模式、自適應(yīng)顏色域變換等,并在2016年2月發(fā)布了HEVC屏幕內(nèi)容擴(kuò)展標(biāo)準(zhǔn)(Screen content coding,SCC)。盡管SCC能夠提高屏幕內(nèi)容編碼效率,但是在某些條件下,重建的屏幕內(nèi)容圖像或視頻依然存在大量噪聲和畸變,降低了重建圖像或視頻的質(zhì)量。因此,有關(guān)屏幕內(nèi)容圖像或視頻高質(zhì)量恢復(fù)的研究就顯得尤為重要。論文基于HEVC框架,重點(diǎn)研究了屏幕內(nèi)容視頻的高質(zhì)量恢復(fù)問題。研究?jī)?nèi)容主要包括:第一,針對(duì)HEVC重建的屏幕內(nèi)容圖像存在畸變和失真的問題,提出一種改進(jìn)的三維塊匹配濾波器(Blcok-matching and 3D Filter,BM3D)作為HEVC屏幕內(nèi)容的后處理濾波器。通過分析屏幕內(nèi)容及其噪聲的特點(diǎn),首先對(duì)塊進(jìn)行分類搜索匹配,使得匹配組中有數(shù)量足夠多的匹配塊;然后對(duì)屏幕內(nèi)容塊進(jìn)行分割,在更靈活的尺寸上分別進(jìn)行匹配,使得組中的匹配塊具有更強(qiáng)的相關(guān)性;最后充分利用圖像的相關(guān)性進(jìn)行協(xié)同濾波并聚合成去噪的圖像。實(shí)驗(yàn)結(jié)果表明該算法不僅可以提高圖像峰值信噪比,對(duì)于主觀質(zhì)量也有明顯的提升。第二,針對(duì)已有的HEVC環(huán)路濾波對(duì)復(fù)合屏幕內(nèi)容視頻的濾波效果不足的問題,提出一種改進(jìn)的自適應(yīng)環(huán)路濾波器(Adaptive Loop Filter,ALF)作為HEVC復(fù)合屏幕內(nèi)容的環(huán)路濾波器,通過對(duì)ALF中基于塊的自適應(yīng)分類方法(Block-based Adaption,BA)的改良提高編碼質(zhì)量。實(shí)驗(yàn)結(jié)果表明,相對(duì)于HEVC SCM-7.0,該算法對(duì)HEVC復(fù)合屏幕內(nèi)容在All intra,Low Delay,Random Access三個(gè)配置下分別能帶來平均1.03%、1.65%、1.33%的 BD-rate 的降低。
[Abstract]:Screen content, image or video are widely used in video conferencing, remote desktop control, wireless display and other devices. Unlike the natural content captured by a camera, screen content usually contains a large amount of text, charts and artificial content, and traditional video coding tools cannot compress it very efficiently. To this end, the Joint Collaborative Team on Video coding working Group (JCT-VCC) is committed to developing standard screen content extension tools for efficient video coding High-Efficiency video coding, such as intra-frame block copy mode, palette mode, adaptive color domain transformation, etc. The HEVC screen content extension standard, Screen content coding, was released in February 2016. Although SCC can improve the efficiency of screen content coding, under some conditions, the reconstructed screen content image or video still has a lot of noise and distortion, which reduces the quality of reconstructed image or video. Therefore, the research of screen content image or video quality restoration is particularly important. Based on the HEVC framework, this paper focuses on the high-quality restoration of screen content video. The main contents are as follows: first, aiming at the distortion and distortion of HEVC reconstructed screen image, an improved 3D block matching filter Blcok-matching and 3D filter BM3D is proposed as a post-processing filter for HEVC screen content. By analyzing the characteristics of screen content and its noise, the block is first classified and matched so that there are enough matching blocks in the matching group, and then the screen content block is segmented to match separately in more flexible dimensions. The matching block in the group has stronger correlation. Finally, the correlation of the image is used to filter and aggregate to the denoised image. The experimental results show that the proposed algorithm can not only improve the PSNR of the image, but also improve the subjective quality. Secondly, aiming at the problem that the existing HEVC loop filter is not effective enough for the video content of composite screen, an improved adaptive Loop filter is proposed as the loop filter for the content of HEVC composite screen. The coding quality is improved by improving the Block-based adaptive classification method in ALF. The experimental results show that compared with HEVC SCM-7.0, the algorithm can reduce the BD-rate of HEVC composite screen by an average of 1.33% (1.65%) under the All intraocular low DelayRandom Access configuration.
【學(xué)位授予單位】：北方工業(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;TP391.41

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉向樂;馮象初;;小波域三維塊匹配圖像去噪[J];計(jì)算機(jī)工程與應(yīng)用;2010年16期

相關(guān)碩士學(xué)位論文 前3條

1 徐忠威;非局部型三維塊匹配去噪算法研究[D];西安電子科技大學(xué);2011年

2 易峰;視頻編碼中去塊濾波技術(shù)的原理與算法研究[D];浙江大學(xué);2006年

3 劉祝華;圖像去噪方法的研究[D];江西師范大學(xué);2005年

，

本文編號(hào)：1807865