The quality of virtual view based on multi-view video （MVD） plus depth format is often evaluated by PSNR or subjectively judged. However, due to synthesizing arbitrary view images, the virtual view images mostly hav...The quality of virtual view based on multi-view video （MVD） plus depth format is often evaluated by PSNR or subjectively judged. However, due to synthesizing arbitrary view images, the virtual view images mostly have no reference images and are only assessed using non-reference. Virtual view images synthesized by depth estimation reference software （DERS） and view synthesis reference software （VSRS） often accompanied with blockiness and other distortions on the edge. In addition, matching level for the depth map and the corresponding texture maps of left and right views also affects the quality of the virtual view. This paper compares the edge similarity of the depth and the corresponding texture maps which generate the intermediate virtual view and combined with the virtual view＇s blockiness which causing blur to evaluate the quality of the virtual view. Experiment results show that the proposed method can reflect the quality of the virtual view better.展开更多
A semi-reference image quality assessment metric based on similarity measurement for synthesizedvirtual viewpoint image (WI) in free-viewpoint television system (FTV) is proposed in this paper. Thekey point of the pro...A semi-reference image quality assessment metric based on similarity measurement for synthesizedvirtual viewpoint image (WI) in free-viewpoint television system (FTV) is proposed in this paper. Thekey point of the proposed metric is taking resemblant information between WI and its neighbor view imagesfor quality assessment to make our metric to be extended to multi-semi-reference image quality assessmenteasily. The proposed metric first extracts impact factors from image features, then combines animage synthesis technique and similarity functions, in which, disparity information are taken into accountfor registering the resemblant regions. Experiments are divided into three phases. Phase Ⅰ is to verify thevalidation of the proposed metric by taking impaired images and original reference into account. The experimentalresults show the agreement between evaluation scores and bio-characteristic of human visualsystem. Phase Ⅱ shows the accordance with Phase Ⅰ by taking neighbor view as reference. The proposedmetric can be taken as a full reference one to evaluate the image quality even though the original referenceis absent. Phase Ⅲ is then performed to evaluate the quality of ⅤⅥ. Evaluation scores in the experimentalresults are able to evaluate the quality of ⅤⅥ.展开更多
The problem of constructing global view of heterogeneous information sources for information sharing is becoming more and more important due to the availability of multiple information sources within the virtual organ...The problem of constructing global view of heterogeneous information sources for information sharing is becoming more and more important due to the availability of multiple information sources within the virtual organization. Global view is defined to provide a unified representation of the information in the different sources by analyzing concept schemas associated with them and resolving possible semantic heterogeneity. An ontology-based method for global view construction is proposed. In the method, （ 1 ） Based on the formal ontologies, the concept of semantic affinity is introduced to assess the level of semantic relationship between information classes from different information sources; （2） Information classes are classified by semantic affinity levels using clustering procedures so that their different representations can be analyzed for unification; （3） Global view is constructed starting from selected clusters by unifying representation of their elements. The application example of using the method in the joint-aerial defense organization is illustrated and the result shows that the proposed method is feasible.展开更多
Image morphing is a powerful tool for visual effect. In this paper, a view interpolation algorithm is proposed to simulate a virtual walk along a street from start position to end position. To simulate a virtual walki...Image morphing is a powerful tool for visual effect. In this paper, a view interpolation algorithm is proposed to simulate a virtual walk along a street from start position to end position. To simulate a virtual walking view needs to create new appearing scene in the vision-vanishing point and disappearing scene beyond the scope of view. To attain these two aims we use two enhanced position parameters to match pixels of source images and target images. One enhanced position parameter is the angular coordinates of pixels. Another enhanced position parameter is the distances from pixels to the vision-vanishing point. According to the parameter values, pixels beyond the scope of view can be ＂moved＂ out in linear interpolation. Result demonstrates the validity of the algorithm. Another advantage of this algorithm is that the enhanced position parameters are based on real locations and walking distances, so it is also an approach to online virtual tour by satellite maps of virtual globe applications such as Google Earth.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.60832003)the Key Laboratory of Advanced Display and System Application(Shanghai University),Ministry of Education,China(Grant No.p200902)+1 种基金the Science and Technology Commission of Shanghai Municipality(Grant No.10510500500)the Natural Science Foundation of Anhui Higher Education Institutions of China(Grant No.KJ2011Z008)
文摘The quality of virtual view based on multi-view video （MVD） plus depth format is often evaluated by PSNR or subjectively judged. However, due to synthesizing arbitrary view images, the virtual view images mostly have no reference images and are only assessed using non-reference. Virtual view images synthesized by depth estimation reference software （DERS） and view synthesis reference software （VSRS） often accompanied with blockiness and other distortions on the edge. In addition, matching level for the depth map and the corresponding texture maps of left and right views also affects the quality of the virtual view. This paper compares the edge similarity of the depth and the corresponding texture maps which generate the intermediate virtual view and combined with the virtual view＇s blockiness which causing blur to evaluate the quality of the virtual view. Experiment results show that the proposed method can reflect the quality of the virtual view better.
基金Supported by the National Natural Science Foundation of China (No. 60672073,60872094)the Program for New Century Excellent Talents in University (NCET-06-0537)the Natural Science Foundation of Ningbo (No. 2007A610037).
文摘A semi-reference image quality assessment metric based on similarity measurement for synthesizedvirtual viewpoint image (WI) in free-viewpoint television system (FTV) is proposed in this paper. Thekey point of the proposed metric is taking resemblant information between WI and its neighbor view imagesfor quality assessment to make our metric to be extended to multi-semi-reference image quality assessmenteasily. The proposed metric first extracts impact factors from image features, then combines animage synthesis technique and similarity functions, in which, disparity information are taken into accountfor registering the resemblant regions. Experiments are divided into three phases. Phase Ⅰ is to verify thevalidation of the proposed metric by taking impaired images and original reference into account. The experimentalresults show the agreement between evaluation scores and bio-characteristic of human visualsystem. Phase Ⅱ shows the accordance with Phase Ⅰ by taking neighbor view as reference. The proposedmetric can be taken as a full reference one to evaluate the image quality even though the original referenceis absent. Phase Ⅲ is then performed to evaluate the quality of ⅤⅥ. Evaluation scores in the experimentalresults are able to evaluate the quality of ⅤⅥ.
基金This project was supported by the National Natural Science Foundation of China (60172012) Hunan Provincial NaturalScience Foundation of China (03JJY3110) .
文摘The problem of constructing global view of heterogeneous information sources for information sharing is becoming more and more important due to the availability of multiple information sources within the virtual organization. Global view is defined to provide a unified representation of the information in the different sources by analyzing concept schemas associated with them and resolving possible semantic heterogeneity. An ontology-based method for global view construction is proposed. In the method, （ 1 ） Based on the formal ontologies, the concept of semantic affinity is introduced to assess the level of semantic relationship between information classes from different information sources; （2） Information classes are classified by semantic affinity levels using clustering procedures so that their different representations can be analyzed for unification; （3） Global view is constructed starting from selected clusters by unifying representation of their elements. The application example of using the method in the joint-aerial defense organization is illustrated and the result shows that the proposed method is feasible.
文摘Image morphing is a powerful tool for visual effect. In this paper, a view interpolation algorithm is proposed to simulate a virtual walk along a street from start position to end position. To simulate a virtual walking view needs to create new appearing scene in the vision-vanishing point and disappearing scene beyond the scope of view. To attain these two aims we use two enhanced position parameters to match pixels of source images and target images. One enhanced position parameter is the angular coordinates of pixels. Another enhanced position parameter is the distances from pixels to the vision-vanishing point. According to the parameter values, pixels beyond the scope of view can be ＂moved＂ out in linear interpolation. Result demonstrates the validity of the algorithm. Another advantage of this algorithm is that the enhanced position parameters are based on real locations and walking distances, so it is also an approach to online virtual tour by satellite maps of virtual globe applications such as Google Earth.
