Depth maps are used for synthesis virtual view in free-viewpoint television （FTV） systems. When depth maps are derived using existing depth estimation methods, the depth distortions will cause undesirable artifacts ...Depth maps are used for synthesis virtual view in free-viewpoint television （FTV） systems. When depth maps are derived using existing depth estimation methods, the depth distortions will cause undesirable artifacts in the synthesized views. To solve this problem, a 3D video quality model base depth maps （D-3DV） for virtual view synthesis and depth map coding in the FTV applications is proposed. First, the relationships between distortions in coded depth map and rendered view are derived. Then, a precisely 3DV quality model based depth characteristics is develop for the synthesized virtual views. Finally, based on D-3DV model, a multilateral filtering is applied as a pre-processed filter to reduce rendering artifacts. The experimental results evaluated by objective and subjective methods indicate that the proposed D-3DV model can reduce bit-rate of depth coding and achieve better rendering quality.展开更多
目的:建立各期宫颈癌患者盆腔动脉血管网的三维可视化数字模型并分析其特点。方法:应用64排螺旋CT血管成像技术(CTA),获得宫颈癌患者CT薄层扫描数据,在腹部医学三维可视化系统进行图像分割及三维重建,然后将重建模型导入Free Form Model...目的:建立各期宫颈癌患者盆腔动脉血管网的三维可视化数字模型并分析其特点。方法:应用64排螺旋CT血管成像技术(CTA),获得宫颈癌患者CT薄层扫描数据,在腹部医学三维可视化系统进行图像分割及三维重建,然后将重建模型导入Free Form Modeling System平台进行平滑、上色、透明化、旋转等操作,获得盆腔动脉血管网三维可视化模型。结果:成功重建出宫颈癌患者盆腔动脉血管网的三维可视化数字模型,可以清楚显示腹主动脉、髂内及髂外动脉、子宫动脉、子宫动脉上行支等主要及细小血管分支,并与骨盆配准后,可清楚了解各血管走行及空间位置,并且随着肿瘤期别的提高,患者盆腔动脉血管网的密度、分支情况等均呈增加趋势。结论:基于CTA数据,应用腹部医学三维可视化系统软件,可以成功重建出活体宫颈癌患者盆腔动脉血管网的三维可视化数字模型,并且各期宫颈癌患者动脉血管网有其不同特点,了解其不同特点对我们的手术或介入治疗有一定的指导意义。展开更多
The Moving Picture Experts Group （MPEG） has been developing a 3D video （3DV） coding standard for depth-based 3DV data representations, especially for multiview video plus depth （MVD） format. With MVD, depth-imag...The Moving Picture Experts Group （MPEG） has been developing a 3D video （3DV） coding standard for depth-based 3DV data representations, especially for multiview video plus depth （MVD） format. With MVD, depth-image-based rendering （DIBR）is used to synthesize virtual views that are based on a few transmitted pairs of texture and depth data. In this paper, we discuss ongoing 3DV standardization and summarize coding tools proposed in the responses to MPEG＇ s call for proposals on 3DV coding.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.60832003)Key Laboratory of Advanced Display and System Application(Shanghai University),Ministry of Education,China(Grant No.P200902)the Key Project of Science and Technology Commission of Shanghai Municipality(Grant No.10510500500)
文摘Depth maps are used for synthesis virtual view in free-viewpoint television （FTV） systems. When depth maps are derived using existing depth estimation methods, the depth distortions will cause undesirable artifacts in the synthesized views. To solve this problem, a 3D video quality model base depth maps （D-3DV） for virtual view synthesis and depth map coding in the FTV applications is proposed. First, the relationships between distortions in coded depth map and rendered view are derived. Then, a precisely 3DV quality model based depth characteristics is develop for the synthesized virtual views. Finally, based on D-3DV model, a multilateral filtering is applied as a pre-processed filter to reduce rendering artifacts. The experimental results evaluated by objective and subjective methods indicate that the proposed D-3DV model can reduce bit-rate of depth coding and achieve better rendering quality.
文摘目的:建立各期宫颈癌患者盆腔动脉血管网的三维可视化数字模型并分析其特点。方法:应用64排螺旋CT血管成像技术(CTA),获得宫颈癌患者CT薄层扫描数据,在腹部医学三维可视化系统进行图像分割及三维重建,然后将重建模型导入Free Form Modeling System平台进行平滑、上色、透明化、旋转等操作,获得盆腔动脉血管网三维可视化模型。结果:成功重建出宫颈癌患者盆腔动脉血管网的三维可视化数字模型,可以清楚显示腹主动脉、髂内及髂外动脉、子宫动脉、子宫动脉上行支等主要及细小血管分支,并与骨盆配准后,可清楚了解各血管走行及空间位置,并且随着肿瘤期别的提高,患者盆腔动脉血管网的密度、分支情况等均呈增加趋势。结论:基于CTA数据,应用腹部医学三维可视化系统软件,可以成功重建出活体宫颈癌患者盆腔动脉血管网的三维可视化数字模型,并且各期宫颈癌患者动脉血管网有其不同特点,了解其不同特点对我们的手术或介入治疗有一定的指导意义。
文摘The Moving Picture Experts Group （MPEG） has been developing a 3D video （3DV） coding standard for depth-based 3DV data representations, especially for multiview video plus depth （MVD） format. With MVD, depth-image-based rendering （DIBR）is used to synthesize virtual views that are based on a few transmitted pairs of texture and depth data. In this paper, we discuss ongoing 3DV standardization and summarize coding tools proposed in the responses to MPEG＇ s call for proposals on 3DV coding.
