提高视频编码效率和质量的前处理技术研究
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摘要
为了获得良好的视频质量和较高的压缩率,视频预处理技术在视频处理与通信应用中占据重要的地位。为了平滑视频中同一镜头图像的亮度,提高视频编码效率,论文深入研究了从视频采集到采集输出之间的背景闪烁消除技术;为了提高图像空间分辨率,论文对图像插值技术研究做了详细的讨论。在两项技术研究中,分别提出了新的解决方法。
背景闪烁是由于光线环境和相机的自动曝光引起场景图像的明暗变化,该现象严重影响了视频的观看效果和压缩效率。本文提出一种新的消除背景闪烁的方法,算法寻找视频序列中的亮度参考帧,使用最小二乘法确定出当前帧和参考帧之间的背景亮度响应函数,使用亮度补偿的方法消除背景闪烁。实验结果表明该算法可以有效地消除背景闪烁现象,用于编码传输可以节省20%-30%的比特率。研究成果已经应用到华为公司的多媒体产品中。
针对传统图像插值算法存在的模糊和锯齿问题,本文提出一种新的基于方向判断的加权图像插值方法。该方法计算四个不同方向的梯度,根据梯度值确定插值方向和每个方向的加权系数,使用加权插值得到最终的图像值。实验结果表明,该方法可以获得较高质量的高分辨率图像。
In order to obtain high video quality and high compression performance, video preprocessing technique plays more important role in video processing and communications. In this dissertation, two processing modules between the video sensor and the output of the capture device are deeply studied. We pay more attention on the background flicker reduction and image interpolation.
Background flicker which is caused by varied light environment and the auto exposure function of video cameras can extremely degrade the video quality and compression efficiency. A new luminance flicker reduction algorithm is proposed in this paper under the circumstances. Firstly, the reference picture for illumination compensation is found out in the proposed algorithm, and then the parameters of the response function of background luminance between the reference picture and the current picture is obtained using the least-square method. Finally, the luminance flicker can be reduced by illumination compensation. Experimental results show that the background luminance flicker can be effectively reduced using this algorithm and bit rate can be saved by 20%-30% when the compensated video sequences are encoded and transmitted. The developed algorithm has been successfully applied to video products of Huawei limited technology cooperation company.
To remove blurring effect and zigzag edges occurring in traditional interpolated images, a new algorithm based on direct-judgment is proposed in his paper. The basic idea is to compute the gradient values of four directions to determine the interpolated directions and its corresponding weighted coefficients, then, the final image is obtained using weighting interpolation. The experimental results show that relatively higher quality images with high definition are achieved.
背景闪烁是由于光线环境和相机的自动曝光引起场景图像的明暗变化,该现象严重影响了视频的观看效果和压缩效率。本文提出一种新的消除背景闪烁的方法,算法寻找视频序列中的亮度参考帧,使用最小二乘法确定出当前帧和参考帧之间的背景亮度响应函数,使用亮度补偿的方法消除背景闪烁。实验结果表明该算法可以有效地消除背景闪烁现象,用于编码传输可以节省20%-30%的比特率。研究成果已经应用到华为公司的多媒体产品中。
针对传统图像插值算法存在的模糊和锯齿问题,本文提出一种新的基于方向判断的加权图像插值方法。该方法计算四个不同方向的梯度,根据梯度值确定插值方向和每个方向的加权系数,使用加权插值得到最终的图像值。实验结果表明,该方法可以获得较高质量的高分辨率图像。
In order to obtain high video quality and high compression performance, video preprocessing technique plays more important role in video processing and communications. In this dissertation, two processing modules between the video sensor and the output of the capture device are deeply studied. We pay more attention on the background flicker reduction and image interpolation.
Background flicker which is caused by varied light environment and the auto exposure function of video cameras can extremely degrade the video quality and compression efficiency. A new luminance flicker reduction algorithm is proposed in this paper under the circumstances. Firstly, the reference picture for illumination compensation is found out in the proposed algorithm, and then the parameters of the response function of background luminance between the reference picture and the current picture is obtained using the least-square method. Finally, the luminance flicker can be reduced by illumination compensation. Experimental results show that the background luminance flicker can be effectively reduced using this algorithm and bit rate can be saved by 20%-30% when the compensated video sequences are encoded and transmitted. The developed algorithm has been successfully applied to video products of Huawei limited technology cooperation company.
To remove blurring effect and zigzag edges occurring in traditional interpolated images, a new algorithm based on direct-judgment is proposed in his paper. The basic idea is to compute the gradient values of four directions to determine the interpolated directions and its corresponding weighted coefficients, then, the final image is obtained using weighting interpolation. The experimental results show that relatively higher quality images with high definition are achieved.
引文
[1]霍俊彦.视频预处理研究.西安电子科技大学硕士学位论文.2006.1.1-10。
[2]毕厚杰.新一代视频压缩编码标准—H.264/AVC.北京.人民邮电出版社,2005.5.14-22。
[3]Yao Wang等著,候正信,杨喜,王文全 等译.视频处理与通信.北京.电子工业出版社,2003,6.5-9。
[4]X.Zhang,N.Fukuda 等.A Signal Processing System on Chip for Digital Cameras.Industrial Electronics Society,26th Annual Conference of the IEEE 2000,1243-1248。
[5]tanyaolin,图像的成像、显示和记录,ppt讲稿。
[6]谢攀,张利,康宗明,谢时根.一种基于尺度变化的DCT自动聚焦算法.清华大学学报(自然科学版).2003,01,第43卷.55-58。
[7]Kazushige Ooi,Keiji Izumi,M itsuyuki Nozaki,等.An advanced autofocus system for video camera using quasi condition reasoning IEEE Trans Consumer Elec.,1990,36:526-529。
[8]Kokaram A C.Motion picture restoration digital algorithms for artifact suppression in degraded motion picture film and video[M].berlin:Springer Verlag,1998。
[9]Pitie F.Removing flicker from old movie[D].Dublin:Trinity College,2002。
[10]Naranjo V,Alboil A.Flicker reduction in old films[A].Processing of the International Conference on Image Processing(ICIP 2000)[C].Canada:IEEE,2000.1300-1303。
[11]Roosmalen V,Bruce P M.Restoration of archived film and Holland:delft University of technology,1999。
[12]Vlachos T.Flicker correction for archived film sequences using a nonlinear model[J].Circuits and Systems for Video Technology,2004,4(14):508-516。
[13]Tetsuya Kuno,Hiroaki Sugiura,Narihiro Matoba.A new automatic exposure system for digital still cameras.IEEE Transactions on Consumer Electronics,1998,44(1):192-199。
[14]周磊,倪强.一种基于块的图像序列闪烁修复方法.上海交通大学学报,2006,40(1):8-11。
[15]谌安军,腾升华,邹谋言.图像序列中亮度闪烁去除.电子与信息学报,2007,29(1):39-42。
[16]Kokaram A C,Dahyot R,and Pitie F.Simultaneous luminance and position stabilization for film and video.Proc.SPIE Volume 5022,Image and Video Communications and Processing,Santa Clara,USA,2003:688-699。
[17]Van Roosmalen P M B,Lagendijk R L,and Biemond J.Correction of intensity flicker in old film sequences.IEEE Trans.On Circuits and Systems for Video Technology,1999,9(7):1013-1019。
[18]OhuchiT,Seto T,and Komatsu T,A robust method of image flicker correction for heavily-corupted old film sequences.In Proc.ICIP-2000,Vancouver,BC,Canada,2000:672-675。
[19]NaranjoV and Albiol A.Flicker reduction in old films.In Proc.ICIP-2000,Vancouver,BC,Canada,2000:657-659。
[20]陆旭光,汪岳峰,胡文刚,金阿立.基于视觉特性的直方图均衡算法改进研究.图像处理,2006,5:229-231。
[21]杨海涛,常义林,王静,霍俊彦.一种基于亮度直方图的自动曝光控制方法.光学学报,2007,27(5):841-847。
[22]Advanced video coding for generic audiovisual services ITU-T Recommendation H.264 2005-03。
[23]S Carrato,G Ramponl,S Marsi.A simple edge-sensitive image interpolation filter[J].Proceeding of ICIP 1996:711-714。
[24]K Jensen,D Anastassiou.Subpixel edge localization and the interpolation of still images[J].IEEE trans.Image Processing,1995,4(3):285-295。
[25]J P Allebach,W P Wong.Edge directed interpolation[J].Proceeding of ICIP,1996,3:701-711。
[26]K Ratakonda,N Ahuja.POCS based adaptive image magnification[J].Proceedin of ICIP 1998:203-207。
[27]L S Debrunner,V Debrunner,M Yao.Edge retaining asymptotic projections onto convex sets for image interpolation[A].Image Analysis And Interpretation,Proceedings of 4th IEEE Southwest Symposium[C].Austin,TX,2000.78-82。
[28]S G Chang,Z Cvetkovic,M Veterli.Resolution enhancement of images using Wavlet transform extrema extrapolation[J].Proceeding of ICASSP,1995,4:2379-2382。
[29]M Gharavi Alkhansari.Resolution enhancement of images using a fractal model [D].Ph.D.thesis,university of Illinois at Urbana,1996。
[30]A K Jain.Fundamentals of Digital Image Processing[M].Prentice Hall,1988。
[31]G Ramponi.Image processing using rational functions[A].Proceedings of the Cost 254 Workshop[C].Budapest,Hungary,1997.6-7。
[32]罗立民,顾照明.三维医学图像重建中极端凹表面的插值[J].东南大学学报(自然科学版),1993,23(1):126-131。
[33]Higgins W E,Morice C,Ritman E L.New shape-based interpolation technique for three-dimensional images[J].1990 International Conference on Acoustics,Speech,and Sigal Processing of IEEE,1990,4:1841-1844。
[34]Grevera G J,Udupa J K.Shaped-based interpolation of multidimensional grey-level imagesp[J].IEEE Trans Med Imageing,1996,15(6):881-892。
[35]Higgins W E,Morice C,Ritman E L.Shape-based interpolation of tree-like structures in three-dimensional images[J].IEEE Trans Med Imaging,1993,12(3):439-450。
[36]Chuang K S,Chen C Y,Yuan L J,et al.Shaped-based grey-level image interpolation[J].Phus Med Bio,1999,44(6):1565-1577。
[37]张俊华,陈建华,王逍.基于边缘移动匹配法的图像插值[J].计算机工程于应用,2003,39(6):73-75。
ZHANG Junhua,CHEN Jianhua,WANG Xiao.Image interpolation based on edge-shifted matching method[J].Computer Engineering and Applications,2003,39(6):73-75。
[38]NIRA S,HAGIT A S,ILAN S,et al.Adaptive Lowcomplexity algorithm for image zooming at fractional scaling Ration[C].21st Convention of the Electrical and Electronic Engineers:IEEE,2000:253-256。
[39]王效灵,陈涛,王颖.边沿自适应图像缩放算法.浙江大学学报,2006,40(9):1507-1510。
[40]Li Xin,Orchard M T.New edge-directed interpolation[J].IEEE Transactions on Image Processwing,2001,10(10):1521-1527。
[41]刘晓松,杨新,汪进.基于统计特征的彩色图像快速插值方法.电子学报,2004,1(32):29-33。
[42]LIU Xiaosong,YANG Xin,WANG Jin.Statistical festure based fast color image interpolation[J].Acta Electronica Ainica,2004,32(1):29-33.(in Chinese)。
[43]Carrato S,Tenze L.A high quality 2\theta image interpolation[J].IEEE Signal Processing Letters,2000,7(6):132-134。
[44]Wang Qing.A contour-preserving image interpolation method[Z].International Conference on Image Processing,Barcelona,2003。
[2]毕厚杰.新一代视频压缩编码标准—H.264/AVC.北京.人民邮电出版社,2005.5.14-22。
[3]Yao Wang等著,候正信,杨喜,王文全 等译.视频处理与通信.北京.电子工业出版社,2003,6.5-9。
[4]X.Zhang,N.Fukuda 等.A Signal Processing System on Chip for Digital Cameras.Industrial Electronics Society,26th Annual Conference of the IEEE 2000,1243-1248。
[5]tanyaolin,图像的成像、显示和记录,ppt讲稿。
[6]谢攀,张利,康宗明,谢时根.一种基于尺度变化的DCT自动聚焦算法.清华大学学报(自然科学版).2003,01,第43卷.55-58。
[7]Kazushige Ooi,Keiji Izumi,M itsuyuki Nozaki,等.An advanced autofocus system for video camera using quasi condition reasoning IEEE Trans Consumer Elec.,1990,36:526-529。
[8]Kokaram A C.Motion picture restoration digital algorithms for artifact suppression in degraded motion picture film and video[M].berlin:Springer Verlag,1998。
[9]Pitie F.Removing flicker from old movie[D].Dublin:Trinity College,2002。
[10]Naranjo V,Alboil A.Flicker reduction in old films[A].Processing of the International Conference on Image Processing(ICIP 2000)[C].Canada:IEEE,2000.1300-1303。
[11]Roosmalen V,Bruce P M.Restoration of archived film and Holland:delft University of technology,1999。
[12]Vlachos T.Flicker correction for archived film sequences using a nonlinear model[J].Circuits and Systems for Video Technology,2004,4(14):508-516。
[13]Tetsuya Kuno,Hiroaki Sugiura,Narihiro Matoba.A new automatic exposure system for digital still cameras.IEEE Transactions on Consumer Electronics,1998,44(1):192-199。
[14]周磊,倪强.一种基于块的图像序列闪烁修复方法.上海交通大学学报,2006,40(1):8-11。
[15]谌安军,腾升华,邹谋言.图像序列中亮度闪烁去除.电子与信息学报,2007,29(1):39-42。
[16]Kokaram A C,Dahyot R,and Pitie F.Simultaneous luminance and position stabilization for film and video.Proc.SPIE Volume 5022,Image and Video Communications and Processing,Santa Clara,USA,2003:688-699。
[17]Van Roosmalen P M B,Lagendijk R L,and Biemond J.Correction of intensity flicker in old film sequences.IEEE Trans.On Circuits and Systems for Video Technology,1999,9(7):1013-1019。
[18]OhuchiT,Seto T,and Komatsu T,A robust method of image flicker correction for heavily-corupted old film sequences.In Proc.ICIP-2000,Vancouver,BC,Canada,2000:672-675。
[19]NaranjoV and Albiol A.Flicker reduction in old films.In Proc.ICIP-2000,Vancouver,BC,Canada,2000:657-659。
[20]陆旭光,汪岳峰,胡文刚,金阿立.基于视觉特性的直方图均衡算法改进研究.图像处理,2006,5:229-231。
[21]杨海涛,常义林,王静,霍俊彦.一种基于亮度直方图的自动曝光控制方法.光学学报,2007,27(5):841-847。
[22]Advanced video coding for generic audiovisual services ITU-T Recommendation H.264 2005-03。
[23]S Carrato,G Ramponl,S Marsi.A simple edge-sensitive image interpolation filter[J].Proceeding of ICIP 1996:711-714。
[24]K Jensen,D Anastassiou.Subpixel edge localization and the interpolation of still images[J].IEEE trans.Image Processing,1995,4(3):285-295。
[25]J P Allebach,W P Wong.Edge directed interpolation[J].Proceeding of ICIP,1996,3:701-711。
[26]K Ratakonda,N Ahuja.POCS based adaptive image magnification[J].Proceedin of ICIP 1998:203-207。
[27]L S Debrunner,V Debrunner,M Yao.Edge retaining asymptotic projections onto convex sets for image interpolation[A].Image Analysis And Interpretation,Proceedings of 4th IEEE Southwest Symposium[C].Austin,TX,2000.78-82。
[28]S G Chang,Z Cvetkovic,M Veterli.Resolution enhancement of images using Wavlet transform extrema extrapolation[J].Proceeding of ICASSP,1995,4:2379-2382。
[29]M Gharavi Alkhansari.Resolution enhancement of images using a fractal model [D].Ph.D.thesis,university of Illinois at Urbana,1996。
[30]A K Jain.Fundamentals of Digital Image Processing[M].Prentice Hall,1988。
[31]G Ramponi.Image processing using rational functions[A].Proceedings of the Cost 254 Workshop[C].Budapest,Hungary,1997.6-7。
[32]罗立民,顾照明.三维医学图像重建中极端凹表面的插值[J].东南大学学报(自然科学版),1993,23(1):126-131。
[33]Higgins W E,Morice C,Ritman E L.New shape-based interpolation technique for three-dimensional images[J].1990 International Conference on Acoustics,Speech,and Sigal Processing of IEEE,1990,4:1841-1844。
[34]Grevera G J,Udupa J K.Shaped-based interpolation of multidimensional grey-level imagesp[J].IEEE Trans Med Imageing,1996,15(6):881-892。
[35]Higgins W E,Morice C,Ritman E L.Shape-based interpolation of tree-like structures in three-dimensional images[J].IEEE Trans Med Imaging,1993,12(3):439-450。
[36]Chuang K S,Chen C Y,Yuan L J,et al.Shaped-based grey-level image interpolation[J].Phus Med Bio,1999,44(6):1565-1577。
[37]张俊华,陈建华,王逍.基于边缘移动匹配法的图像插值[J].计算机工程于应用,2003,39(6):73-75。
ZHANG Junhua,CHEN Jianhua,WANG Xiao.Image interpolation based on edge-shifted matching method[J].Computer Engineering and Applications,2003,39(6):73-75。
[38]NIRA S,HAGIT A S,ILAN S,et al.Adaptive Lowcomplexity algorithm for image zooming at fractional scaling Ration[C].21st Convention of the Electrical and Electronic Engineers:IEEE,2000:253-256。
[39]王效灵,陈涛,王颖.边沿自适应图像缩放算法.浙江大学学报,2006,40(9):1507-1510。
[40]Li Xin,Orchard M T.New edge-directed interpolation[J].IEEE Transactions on Image Processwing,2001,10(10):1521-1527。
[41]刘晓松,杨新,汪进.基于统计特征的彩色图像快速插值方法.电子学报,2004,1(32):29-33。
[42]LIU Xiaosong,YANG Xin,WANG Jin.Statistical festure based fast color image interpolation[J].Acta Electronica Ainica,2004,32(1):29-33.(in Chinese)。
[43]Carrato S,Tenze L.A high quality 2\theta image interpolation[J].IEEE Signal Processing Letters,2000,7(6):132-134。
[44]Wang Qing.A contour-preserving image interpolation method[Z].International Conference on Image Processing,Barcelona,2003。