In this paper, we propose a fast global illumination solution for interactive lighting design. Using our method, light sources and the viewpoint are movable, and the characteristics of materials can be modified (assuming low-frequency BRDF) during rendering. Our solution is based on particle tracing (a variation of photon mapping) and final gathering. We assume that objects in the input scene are static, and pre-compute potential light paths for particle tracing and final gathering. To perform final gathering fast, we propose an efficient technique called Hierarchical Histogram Estimation for rapid estimation of radiances from the distribution of the particles. The rendering process of our method can be fully implemented on the GPU and our method achieves interactive frame rates for rendering scenes with even more than 100,000 triangles.
{"title":"Global Illumination for Interactive Lighting Design Using Light Path Pre-Computation and Hierarchical Histogram Estimation","authors":"Yonghao Yue, Kei Iwasaki, Y. Dobashi, T. Nishita","doi":"10.1109/PG.2007.60","DOIUrl":"https://doi.org/10.1109/PG.2007.60","url":null,"abstract":"In this paper, we propose a fast global illumination solution for interactive lighting design. Using our method, light sources and the viewpoint are movable, and the characteristics of materials can be modified (assuming low-frequency BRDF) during rendering. Our solution is based on particle tracing (a variation of photon mapping) and final gathering. We assume that objects in the input scene are static, and pre-compute potential light paths for particle tracing and final gathering. To perform final gathering fast, we propose an efficient technique called Hierarchical Histogram Estimation for rapid estimation of radiances from the distribution of the particles. The rendering process of our method can be fully implemented on the GPU and our method achieves interactive frame rates for rendering scenes with even more than 100,000 triangles.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122374129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a novel integrative information visualization framework for cross-subject neuroimaging data analysis. The framework can integrate multimodal information captured by different imaging modalities and population-based statistical information presented by different subjects. In this framework, accurate registration of cortical structures is the foundation for the information integration across population. We present a non-rigid intersubject brain surface registration method using conformal structure and spherical thin-plate splines. Spherical thin-plate splines are designed to explicitly match prominent homologous landmarks, and meanwhile, interpolate a global deformation field on the spherical domain, registering brain surfaces in a transformed space. Subsequently, an approach for the integrative information fusion and visualization is presented to handle multimodality neuroimaging data. The entire framework demonstrates its usefulness in multimodality neuroimaging data analysis across subjects.
{"title":"Integrative Information Visualization of Multimodality Neuroimaging Data","authors":"Guangyu Zou, Jing Hua, Ming Dong","doi":"10.1109/PG.2007.59","DOIUrl":"https://doi.org/10.1109/PG.2007.59","url":null,"abstract":"This paper presents a novel integrative information visualization framework for cross-subject neuroimaging data analysis. The framework can integrate multimodal information captured by different imaging modalities and population-based statistical information presented by different subjects. In this framework, accurate registration of cortical structures is the foundation for the information integration across population. We present a non-rigid intersubject brain surface registration method using conformal structure and spherical thin-plate splines. Spherical thin-plate splines are designed to explicitly match prominent homologous landmarks, and meanwhile, interpolate a global deformation field on the spherical domain, registering brain surfaces in a transformed space. Subsequently, an approach for the integrative information fusion and visualization is presented to handle multimodality neuroimaging data. The entire framework demonstrates its usefulness in multimodality neuroimaging data analysis across subjects.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127642767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We introduce an algorithm for approximating a 2-manifold 3D mesh by a set of developable surfaces. Each developable surface is a generalized cylinder represented as a strip of triangles not necessarily taken from the original mesh. Our algorithm is automatic, creates easy-to-assemble pieces, and provides L_alpha global error bounds. The approximation quality is controlled by a user-supplied parameter specifying the allowed Hausdorff distance between the input mesh and its piecewise-developable approximation. The strips generated by our algorithm may be parameterized to conform with the parameterization of the original mesh, if given, to facilitate texture mapping. We demonstrate this by physically assembling papercraft models from the strips generated by our algorithm when run on several polygonal 3D mesh data sets.
{"title":"Papercraft Models using Generalized Cylinders","authors":"Fady Massarwi, C. Gotsman, G. Elber","doi":"10.1109/PG.2007.46","DOIUrl":"https://doi.org/10.1109/PG.2007.46","url":null,"abstract":"We introduce an algorithm for approximating a 2-manifold 3D mesh by a set of developable surfaces. Each developable surface is a generalized cylinder represented as a strip of triangles not necessarily taken from the original mesh. Our algorithm is automatic, creates easy-to-assemble pieces, and provides L_alpha global error bounds. The approximation quality is controlled by a user-supplied parameter specifying the allowed Hausdorff distance between the input mesh and its piecewise-developable approximation. The strips generated by our algorithm may be parameterized to conform with the parameterization of the original mesh, if given, to facilitate texture mapping. We demonstrate this by physically assembling papercraft models from the strips generated by our algorithm when run on several polygonal 3D mesh data sets.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130999711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Grzegorz Krawczyk, Rafał K. Mantiuk, Dorota Zdrojewska, H. Seidel
This paper presents an image-space approximation technique for real-time subsurface scattering. We first create transmitted irradiance samples on shadow maps and then estimate single scattering efficiently using a method similar to shadow mapping, with adaptive deterministic sampling. We incorporate this single-scattering with a recently proposed technique for multiple scattering. We demonstrate that our technique produces high-quality images of animated scenes. We archived hundreds of frames per second on graphics hardware without lengthy preprocessing.
{"title":"Real-Time Approximate Subsurface Scattering on Graphics Hardware","authors":"Grzegorz Krawczyk, Rafał K. Mantiuk, Dorota Zdrojewska, H. Seidel","doi":"10.1109/PG.2007.12","DOIUrl":"https://doi.org/10.1109/PG.2007.12","url":null,"abstract":"This paper presents an image-space approximation technique for real-time subsurface scattering. We first create transmitted irradiance samples on shadow maps and then estimate single scattering efficiently using a method similar to shadow mapping, with adaptive deterministic sampling. We incorporate this single-scattering with a recently proposed technique for multiple scattering. We demonstrate that our technique produces high-quality images of animated scenes. We archived hundreds of frames per second on graphics hardware without lengthy preprocessing.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127519125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wai-Shun Tong, Chi-Keung Tang, M. S. Brown, Ying-Qing Xu
Cosmetic makeup is used worldwide as a means to enhance beauty and express moods. An art form in its own right, cosmetic styles continuously change and evolve to reflect cultural and societal trends. While countless magazines and books are dedicated to demonstrating cosmetic art, the actual application of makeup still remains a physical endeavor. In this paper, we describe a procedure to apply cosmetic makeup to the image of a person's face with the click of a mouse. Our approach works from before- and-after example images created by professional makeup artists. Using our "cosmetic-transfer" procedure, we can realistically transfer the cosmetic style captured in the example-pair to another person's face. This greatly reduces the time and effort needed to demonstrate a cosmetic style on a new person's face. In addition, our approach can be used to mix-and- match, and even fine-tune, example styles, all virtually, without the need for any physical makeup.
{"title":"Example-Based Cosmetic Transfer","authors":"Wai-Shun Tong, Chi-Keung Tang, M. S. Brown, Ying-Qing Xu","doi":"10.1109/PG.2007.31","DOIUrl":"https://doi.org/10.1109/PG.2007.31","url":null,"abstract":"Cosmetic makeup is used worldwide as a means to enhance beauty and express moods. An art form in its own right, cosmetic styles continuously change and evolve to reflect cultural and societal trends. While countless magazines and books are dedicated to demonstrating cosmetic art, the actual application of makeup still remains a physical endeavor. In this paper, we describe a procedure to apply cosmetic makeup to the image of a person's face with the click of a mouse. Our approach works from before- and-after example images created by professional makeup artists. Using our \"cosmetic-transfer\" procedure, we can realistically transfer the cosmetic style captured in the example-pair to another person's face. This greatly reduces the time and effort needed to demonstrate a cosmetic style on a new person's face. In addition, our approach can be used to mix-and- match, and even fine-tune, example styles, all virtually, without the need for any physical makeup.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127613529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We overview a new method for computing the arrangement of semi-algebraic curves. A subdivision approach is used to compute the topology of the algebraic objects and to segment the boundary of regions defined by these objects. An efficient insertion technique is described, which detects regions in conflict and updates the underlying arrangement structure. We describe the general framework of this method, the main region insertion operation and the specializations of the key ingredients for the different types of objects: implicit, parametric or piecewise linear curves.
{"title":"A Subdivision Arrangement Algorithm for Semi-Algebraic Curves: An Overview","authors":"Julien Wintz, B. Mourrain","doi":"10.1109/PG.2007.18","DOIUrl":"https://doi.org/10.1109/PG.2007.18","url":null,"abstract":"We overview a new method for computing the arrangement of semi-algebraic curves. A subdivision approach is used to compute the topology of the algebraic objects and to segment the boundary of regions defined by these objects. An efficient insertion technique is described, which detects regions in conflict and updates the underlying arrangement structure. We describe the general framework of this method, the main region insertion operation and the specializations of the key ingredients for the different types of objects: implicit, parametric or piecewise linear curves.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"130 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115752250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caustics are important visual phenomena, as well as challenging global illumination effects in computer graphics. Physically caustics can be interpreted from one of two perspectives: in terms of photons gathered on scene geometry, or in terms of a pair of caustic surfaces. These caustic surfaces are swept by the foci of light rays. In this paper, we develop a novel algorithm to approximate caustic surfaces of sampled rays. Our approach locally parameterizes rays by their intersections with a pair of parallel planes. We show neighboring ray triplets are constrained to pass simultaneously through two slits, which rule the caustic surfaces. We derive a ray characteristic equation to compute the two slits, and hence, the caustic surfaces. Using the characteristic equation, we develop a GPU-based algorithm to render the caustics. Our approach produces sharp and clear caustics using much fewer ray samples than the photon mapping method and it also maintains high spatial and temporal coherency. Finally, we present a normal-ray surface representation that locally parameterizes the normals about a surface point as rays. Computing the normal ray caustic surfaces leads to a novel real-time discrete shape operator.
{"title":"Image-Space Caustics and Curvatures","authors":"Xuan Yu, Feng Li, Jingyi Yu","doi":"10.1109/PG.2007.35","DOIUrl":"https://doi.org/10.1109/PG.2007.35","url":null,"abstract":"Caustics are important visual phenomena, as well as challenging global illumination effects in computer graphics. Physically caustics can be interpreted from one of two perspectives: in terms of photons gathered on scene geometry, or in terms of a pair of caustic surfaces. These caustic surfaces are swept by the foci of light rays. In this paper, we develop a novel algorithm to approximate caustic surfaces of sampled rays. Our approach locally parameterizes rays by their intersections with a pair of parallel planes. We show neighboring ray triplets are constrained to pass simultaneously through two slits, which rule the caustic surfaces. We derive a ray characteristic equation to compute the two slits, and hence, the caustic surfaces. Using the characteristic equation, we develop a GPU-based algorithm to render the caustics. Our approach produces sharp and clear caustics using much fewer ray samples than the photon mapping method and it also maintains high spatial and temporal coherency. Finally, we present a normal-ray surface representation that locally parameterizes the normals about a surface point as rays. Computing the normal ray caustic surfaces leads to a novel real-time discrete shape operator.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128340324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Minjung Son, Henry Kang, Yunjin Lee, Seungyong Lee
We present a novel scheme for automatically generating line drawings from 2D images, aiming to facilitate effective visual communication. In contrast to conventional edge detectors, our technique imitates the human line drawing process and consists of two parts: line extraction and line rendering. We propose a novel line extraction method based on likelihood-function estimation, which effectively finds the genuine shape boundaries. We consider the feature scale and the blurriness of lines with which the detail and the focus-level of lines are controlled in the rendering. We also employ stroke textures to provide a variety of illustration styles. Experimental results demonstrate that our technique generates various kinds of line drawings from 2D images enabled by the control over detail, focus, and style.
{"title":"Abstract Line Drawings from 2D Images","authors":"Minjung Son, Henry Kang, Yunjin Lee, Seungyong Lee","doi":"10.1109/PG.2007.63","DOIUrl":"https://doi.org/10.1109/PG.2007.63","url":null,"abstract":"We present a novel scheme for automatically generating line drawings from 2D images, aiming to facilitate effective visual communication. In contrast to conventional edge detectors, our technique imitates the human line drawing process and consists of two parts: line extraction and line rendering. We propose a novel line extraction method based on likelihood-function estimation, which effectively finds the genuine shape boundaries. We consider the feature scale and the blurriness of lines with which the detail and the focus-level of lines are controlled in the rendering. We also employ stroke textures to provide a variety of illustration styles. Experimental results demonstrate that our technique generates various kinds of line drawings from 2D images enabled by the control over detail, focus, and style.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130903393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Grzegorz Krawczyk, Rafał K. Mantiuk, Dorota Zdrojewska, Hans-Peter Seidel
Both high dynamic range images and their tone mapped correspondents contain relative luminance values which have to be mapped on a scale of available gray levels of a display. Such mapping includes brightness adjustment, which has a direct impact on the final image appearance and the observers' assessment of image quality. We conduct a psychophysical experiment in which subjects adjust image brightness to match their preference. We observe that the brightness choice is consistent across subjects and is primarily affected by image content. We investigate popular methods for automatic brightness adjustment and show a significant inaccuracy for a group of images. The incorrect brightness adjustment degrades in these cases perceived image quality. We identify characteristics of images that are highly correlated with the subjects' choice of brightness and develop an improved model for the brightness adjustment.
{"title":"Brightness Adjustment for HDR and Tone Mapped Images","authors":"Grzegorz Krawczyk, Rafał K. Mantiuk, Dorota Zdrojewska, Hans-Peter Seidel","doi":"10.1109/PG.2007.38","DOIUrl":"https://doi.org/10.1109/PG.2007.38","url":null,"abstract":"Both high dynamic range images and their tone mapped correspondents contain relative luminance values which have to be mapped on a scale of available gray levels of a display. Such mapping includes brightness adjustment, which has a direct impact on the final image appearance and the observers' assessment of image quality. We conduct a psychophysical experiment in which subjects adjust image brightness to match their preference. We observe that the brightness choice is consistent across subjects and is primarily affected by image content. We investigate popular methods for automatic brightness adjustment and show a significant inaccuracy for a group of images. The incorrect brightness adjustment degrades in these cases perceived image quality. We identify characteristics of images that are highly correlated with the subjects' choice of brightness and develop an improved model for the brightness adjustment.","PeriodicalId":376934,"journal":{"name":"15th Pacific Conference on Computer Graphics and Applications (PG'07)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133919595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：