This study proposes a refined methodology for controlling building heights in heritage areas.In order to protect the visual integrity of the heritage area,buildings should not obstruct the view from important site poi...This study proposes a refined methodology for controlling building heights in heritage areas.In order to protect the visual integrity of the heritage area,buildings should not obstruct the view from important site points and viewpoints to the periphery.By calculating the building height thresholds that buildings should not obscure the view from each viewpoint,the results of which are weighted and superimposed,and the values are extracted to each building unit as a refined building height control guideline.This study takes the Zhoukoudian area as a case study,applies the refined building height control criterion to the Zhoukoudian Site,and relies on this refined criterion to assess the visual integrity of the Zhoukoudian area,so as to realize the scientific planning and monitoring of the Zhoukoudian area.The refined building height control method can be applied to building height planning and visual landscape protection in large heritage areas.展开更多
This paper is a historical overview of the development of visual impact assessment (VIA) methodology as implemented by US Federal agencies from the 1960s until the current time. VIA methods are to be used as part of e...This paper is a historical overview of the development of visual impact assessment (VIA) methodology as implemented by US Federal agencies from the 1960s until the current time. VIA methods are to be used as part of environmental impact assessment for projects which could have significant impact on landscape aesthetics. Also included are methodological challenges with current large-scale renewable energy development in the US and Europe.展开更多
Quality of experience（QoE） has been one of the most important factors for service providers and operators to develop and deploy services. Previous works have shown that Weber-Fechner law（WFL） can be used to promot...Quality of experience（QoE） has been one of the most important factors for service providers and operators to develop and deploy services. Previous works have shown that Weber-Fechner law（WFL） can be used to promote the accuracy of best-effort（BE） services＇ QoE assessment. In this paper, based on WFL, we take a deep insight into the visual information of BE services and its role in WFL, especially in web browsing services, and propose an enhanced QoE assessment model for BE services by taking the visual information into account. Both images and texts visual information are extracted and combined to get the visual information for web pages. Finally, a subjective experiment is performed to validate performance of proposed QoE assessment model, which shows that it performs better than traditional WFL based model.展开更多
The visual integrity of mountains contributing to cultural landscapes as nature-culture attributes is often obscured by the vertical intrusive built environment,especially in bufer areas of protected heritage zones.Th...The visual integrity of mountains contributing to cultural landscapes as nature-culture attributes is often obscured by the vertical intrusive built environment,especially in bufer areas of protected heritage zones.Therefore,this study argued that even low/medium-rise buildings that inappropriately appear in the horizontal visual plane could be a factor increasing sensitivity to this panoramic view.An integrative tool–visual sensitivity assessment–consists of Viewshed and Skyline analysis considering the pedestrian’s visual limitation in identifying the sensitive areas of the mountain view corridor in the historic city of Chiang Mai.The visible mountain areas(VMAs)were determined as a baseline,and their relationship with the visible building areas(VBAs)was then examined using statistical correlation to defne a strong negative relationship as the visual sensitive areas in fve zones.The results showed that the bufer zone was found to have more areas with visual sensitivity values,but this varies depending on the characteristics of buildings and the assessment from the view corridor.Meanwhile,in height-restricted areas,such as historic area zone 5,there are some concerns about the visual intrusion,which necessitates continuous monitoring using the assessment result as a guideline.Incorporating the results into implementation could support cultural landscape conservation in Chiang Mai city.The method is applicable in historic cities with similar settings to produce the baseline for the built environment that is harmonious with the cultural and historical characteristics of the city and with respect to its broader setting.展开更多
Recent developments in 3D graphics technology have led to extensive processes on 3D meshes(e.g.,compression,simplification,transmission and watermarking),these processes unavoidably cause the visual perceptual degrada...Recent developments in 3D graphics technology have led to extensive processes on 3D meshes(e.g.,compression,simplification,transmission and watermarking),these processes unavoidably cause the visual perceptual degradation of the 3D objects.The existing mesh visual quality evaluation metrics either require topology constrain or fail to reflect the perceived visual quality.Meanwhile,for the 3D objects that are observed on 2D screens by the users,it is reasonable to apply image metric to assess the distortion caused by mesh simplification.We attempt to explore the efficiency of image metric for assessing the visual fidelity of the simplified 3D model in this paper.For this purpose,several latest and most effective image metrics,2D snapshots,number and pooling algorithms are involved in our study,and finally tested on the IEETA simplification database.The statistical data allow the researcher to select the optimal parameter for this image-based mesh visual quality assessment and provide a new perspective for the design and performance assessment of mesh simplification algorithms.展开更多
Digital maps of soil properties are now widely available.End-users now can access several digital soil mapping(DSM)products of soil properties,produced using different models,calibration/training data,and covariates a...Digital maps of soil properties are now widely available.End-users now can access several digital soil mapping(DSM)products of soil properties,produced using different models,calibration/training data,and covariates at various spatial scales from global to local.Therefore,there is an urgent need to provide easy-to-understand tools to communicate map uncertainty and help end-users assess the reliability of DSM products for use at local scales.In this study,we used a large amount of hand-feel soil texture(HFST)data to assess the performance of various published DSM products on the prediction of soil particle size distribution in Central France.We tested four DSM products for soil texture prediction developed at various scales(global,continental,national,and regional)by comparing their predictions with approximately 3200 HFST observations realized on a 1:50000 soil survey conducted after release of these DSM products.We used both visual comparisons and quantitative indicators to match the DSM predictions and HFST observations.The comparison between the low-cost HFST observations and DSM predictions clearly showed the applicability of various DSM products,with the prediction accuracy increasing from global to regional predictions.This simple evaluation can determine which products can be used at the local scale and if more accurate DSM products are required.展开更多
Holographic displays have the promise to be the ultimate 3D display technology,able to account for all visual cues.Recent advances in photonics and electronics gave rise to high-resolution holographic display prototyp...Holographic displays have the promise to be the ultimate 3D display technology,able to account for all visual cues.Recent advances in photonics and electronics gave rise to high-resolution holographic display prototypes,indicating that they may become widely available in the near future.One major challenge in driving those display systems is computational:computer generated holography(CGH)consists of numerically simulating diffraction,which is very computationally intensive.Our goal in this paper is to give a broad overview of the state-of-the-art in CGH.We make a classification of modern CGH algorithms,we describe different algorithmic CGH acceleration techniques,discuss the latest dedicated hardware solutions and indicate how to evaluate the perceptual quality of CGH.We summarize our findings,discuss remaining challenges and make projections on the future of CGH.展开更多
In computer graphics, various processing operations are applied to 3D triangle meshes and these processes often involve distortions, which affect the visual quality of surface geometry. In this context, perceptual qua...In computer graphics, various processing operations are applied to 3D triangle meshes and these processes often involve distortions, which affect the visual quality of surface geometry. In this context, perceptual quality assessment of 3D triangle meshes has become a crucial issue. In this paper, we propose a new objective quality metric for assessing the visual difference between a reference mesh and a corresponding distorted mesh. Our analysis indicates that the overall quality of a distorted mesh is sensitive to the distortion distribution. The proposed metric is based on a spatial pooling strategy and statistical descriptors of the dis- tortion distribution. We generate a perceptual distortion map for vertices in the reference mesh while taking into account the visual masking effect of the human visual system. The proposed metric extracts statistical descriptors from the dis- tortion map as the feature vector to represent the overall mesh quality. With the feature vector as input, we adopt a support vector regression model to predict the mesh quality score. We validate the performance of our method with three publicly available databases, and the comparison with state-of-the-art metrics demonstrates the superiority of our method. Experimental results show that our proposed method achieves a high correlation between objective assessment and subjective scores.展开更多
文摘This study proposes a refined methodology for controlling building heights in heritage areas.In order to protect the visual integrity of the heritage area,buildings should not obstruct the view from important site points and viewpoints to the periphery.By calculating the building height thresholds that buildings should not obscure the view from each viewpoint,the results of which are weighted and superimposed,and the values are extracted to each building unit as a refined building height control guideline.This study takes the Zhoukoudian area as a case study,applies the refined building height control criterion to the Zhoukoudian Site,and relies on this refined criterion to assess the visual integrity of the Zhoukoudian area,so as to realize the scientific planning and monitoring of the Zhoukoudian area.The refined building height control method can be applied to building height planning and visual landscape protection in large heritage areas.
文摘This paper is a historical overview of the development of visual impact assessment (VIA) methodology as implemented by US Federal agencies from the 1960s until the current time. VIA methods are to be used as part of environmental impact assessment for projects which could have significant impact on landscape aesthetics. Also included are methodological challenges with current large-scale renewable energy development in the US and Europe.
基金supported by the Beijing Municipal Science and Technology Commission Research Fund Project (D151100000115002 )the Ministry of Education. CMCC Research fund (MCM20130132)
文摘Quality of experience（QoE） has been one of the most important factors for service providers and operators to develop and deploy services. Previous works have shown that Weber-Fechner law（WFL） can be used to promote the accuracy of best-effort（BE） services＇ QoE assessment. In this paper, based on WFL, we take a deep insight into the visual information of BE services and its role in WFL, especially in web browsing services, and propose an enhanced QoE assessment model for BE services by taking the visual information into account. Both images and texts visual information are extracted and combined to get the visual information for web pages. Finally, a subjective experiment is performed to validate performance of proposed QoE assessment model, which shows that it performs better than traditional WFL based model.
基金JSPS KAKENHI Grant Numbers JP20KK0101,JP20F40066.
文摘The visual integrity of mountains contributing to cultural landscapes as nature-culture attributes is often obscured by the vertical intrusive built environment,especially in bufer areas of protected heritage zones.Therefore,this study argued that even low/medium-rise buildings that inappropriately appear in the horizontal visual plane could be a factor increasing sensitivity to this panoramic view.An integrative tool–visual sensitivity assessment–consists of Viewshed and Skyline analysis considering the pedestrian’s visual limitation in identifying the sensitive areas of the mountain view corridor in the historic city of Chiang Mai.The visible mountain areas(VMAs)were determined as a baseline,and their relationship with the visible building areas(VBAs)was then examined using statistical correlation to defne a strong negative relationship as the visual sensitive areas in fve zones.The results showed that the bufer zone was found to have more areas with visual sensitivity values,but this varies depending on the characteristics of buildings and the assessment from the view corridor.Meanwhile,in height-restricted areas,such as historic area zone 5,there are some concerns about the visual intrusion,which necessitates continuous monitoring using the assessment result as a guideline.Incorporating the results into implementation could support cultural landscape conservation in Chiang Mai city.The method is applicable in historic cities with similar settings to produce the baseline for the built environment that is harmonious with the cultural and historical characteristics of the city and with respect to its broader setting.
文摘Recent developments in 3D graphics technology have led to extensive processes on 3D meshes(e.g.,compression,simplification,transmission and watermarking),these processes unavoidably cause the visual perceptual degradation of the 3D objects.The existing mesh visual quality evaluation metrics either require topology constrain or fail to reflect the perceived visual quality.Meanwhile,for the 3D objects that are observed on 2D screens by the users,it is reasonable to apply image metric to assess the distortion caused by mesh simplification.We attempt to explore the efficiency of image metric for assessing the visual fidelity of the simplified 3D model in this paper.For this purpose,several latest and most effective image metrics,2D snapshots,number and pooling algorithms are involved in our study,and finally tested on the IEETA simplification database.The statistical data allow the researcher to select the optimal parameter for this image-based mesh visual quality assessment and provide a new perspective for the design and performance assessment of mesh simplification algorithms.
文摘Digital maps of soil properties are now widely available.End-users now can access several digital soil mapping(DSM)products of soil properties,produced using different models,calibration/training data,and covariates at various spatial scales from global to local.Therefore,there is an urgent need to provide easy-to-understand tools to communicate map uncertainty and help end-users assess the reliability of DSM products for use at local scales.In this study,we used a large amount of hand-feel soil texture(HFST)data to assess the performance of various published DSM products on the prediction of soil particle size distribution in Central France.We tested four DSM products for soil texture prediction developed at various scales(global,continental,national,and regional)by comparing their predictions with approximately 3200 HFST observations realized on a 1:50000 soil survey conducted after release of these DSM products.We used both visual comparisons and quantitative indicators to match the DSM predictions and HFST observations.The comparison between the low-cost HFST observations and DSM predictions clearly showed the applicability of various DSM products,with the prediction accuracy increasing from global to regional predictions.This simple evaluation can determine which products can be used at the local scale and if more accurate DSM products are required.
基金This research was funded by the Research Foundation-Flanders(FWO),Junior postdoctoral fellowship(12ZQ220N),the joint JSPS-FWO scientific cooperation program(VS07820N)the Japan Society for the Promotion of Science(19H04132 and JPJSBP120202302)。
文摘Holographic displays have the promise to be the ultimate 3D display technology,able to account for all visual cues.Recent advances in photonics and electronics gave rise to high-resolution holographic display prototypes,indicating that they may become widely available in the near future.One major challenge in driving those display systems is computational:computer generated holography(CGH)consists of numerically simulating diffraction,which is very computationally intensive.Our goal in this paper is to give a broad overview of the state-of-the-art in CGH.We make a classification of modern CGH algorithms,we describe different algorithmic CGH acceleration techniques,discuss the latest dedicated hardware solutions and indicate how to evaluate the perceptual quality of CGH.We summarize our findings,discuss remaining challenges and make projections on the future of CGH.
文摘In computer graphics, various processing operations are applied to 3D triangle meshes and these processes often involve distortions, which affect the visual quality of surface geometry. In this context, perceptual quality assessment of 3D triangle meshes has become a crucial issue. In this paper, we propose a new objective quality metric for assessing the visual difference between a reference mesh and a corresponding distorted mesh. Our analysis indicates that the overall quality of a distorted mesh is sensitive to the distortion distribution. The proposed metric is based on a spatial pooling strategy and statistical descriptors of the dis- tortion distribution. We generate a perceptual distortion map for vertices in the reference mesh while taking into account the visual masking effect of the human visual system. The proposed metric extracts statistical descriptors from the dis- tortion map as the feature vector to represent the overall mesh quality. With the feature vector as input, we adopt a support vector regression model to predict the mesh quality score. We validate the performance of our method with three publicly available databases, and the comparison with state-of-the-art metrics demonstrates the superiority of our method. Experimental results show that our proposed method achieves a high correlation between objective assessment and subjective scores.
