In this paper, we describe the use of threshold modulation to remove the visual artifacts contained in the variable-coefficient error-diffusion algorithm. To obtain a suitable parameter set for the threshold modulation, a cost function used for the search of optimal parameters is designed. An optimal diffusion parameter set, as well as the corresponding threshold modulation strength values, is thus obtained. Experiments over this new set of parameters show that, compared with the original variable-coefficient error-diffusion algorithm, threshold modulation can remove visual anomalies more effectively. The result of the new algorithm is an artifact-free halftoning in the full range of intensities. Fourier analysis of the experimental results further support this conclusion.
{"title":"Improving mid-tone quality of variable-coefficient error diffusion using threshold modulation","authors":"Bingfeng Zhou, X. Fang","doi":"10.1145/1201775.882289","DOIUrl":"https://doi.org/10.1145/1201775.882289","url":null,"abstract":"In this paper, we describe the use of threshold modulation to remove the visual artifacts contained in the variable-coefficient error-diffusion algorithm. To obtain a suitable parameter set for the threshold modulation, a cost function used for the search of optimal parameters is designed. An optimal diffusion parameter set, as well as the corresponding threshold modulation strength values, is thus obtained. Experiments over this new set of parameters show that, compared with the original variable-coefficient error-diffusion algorithm, threshold modulation can remove visual anomalies more effectively. The result of the new algorithm is an artifact-free halftoning in the full range of intensities. Fourier analysis of the experimental results further support this conclusion.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134129661","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}
The latest real-time graphics architectures include programmable floating-point vertex and fragment processors, with support for data-dependent control flow in the vertex processor. We present a programming language and a supporting system that are designed for programming these stream processors. The language follows the philosophy of C, in that it is a hardware-oriented, general-purpose language, rather than an application-specific shading language. The language includes a variety of facilities designed to support the key architectural features of programmable graphics processors, and is designed to support multiple generations of graphics architectures with different levels of functionality. The system supports both of the major 3D graphics APIs: OpenGL and Direct3D. This paper identifies many of the choices that we faced as we designed the system, and explains why we made the decisions that we did.
{"title":"Cg: a system for programming graphics hardware in a C-like language","authors":"W. Mark, R. Glanville, K. Akeley, M. Kilgard","doi":"10.1145/1201775.882362","DOIUrl":"https://doi.org/10.1145/1201775.882362","url":null,"abstract":"The latest real-time graphics architectures include programmable floating-point vertex and fragment processors, with support for data-dependent control flow in the vertex processor. We present a programming language and a supporting system that are designed for programming these stream processors. The language follows the philosophy of C, in that it is a hardware-oriented, general-purpose language, rather than an application-specific shading language. The language includes a variety of facilities designed to support the key architectural features of programmable graphics processors, and is designed to support multiple generations of graphics architectures with different levels of functionality. The system supports both of the major 3D graphics APIs: OpenGL and Direct3D. This paper identifies many of the choices that we faced as we designed the system, and explains why we made the decisions that we did.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"193 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129018385","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}
Michael Gleicher, Hyun Joon Shin, Lucas Kovar, Andrew Jepsen
Our methodology allows quality motions to be synthesized in a controllable manner with little run-time overhead. A corpus of motion capture data is processed into a set of short clips that can be “snapped together” (concatenated) into seamless streams of motions at run time. This process is guided by an author who identifies (with help from our system) character poses that appear frequently in the corpus. Each such pose serves as a jump point at which any motion that enters can be followed by any motion that leaves, as shown in Figures 1 and 2. The result is a simple graph structure that allows clips to be connected into longer motions.
{"title":"Snap-together motion: assembling run-time animations","authors":"Michael Gleicher, Hyun Joon Shin, Lucas Kovar, Andrew Jepsen","doi":"10.1145/1201775.882333","DOIUrl":"https://doi.org/10.1145/1201775.882333","url":null,"abstract":"Our methodology allows quality motions to be synthesized in a controllable manner with little run-time overhead. A corpus of motion capture data is processed into a set of short clips that can be “snapped together” (concatenated) into seamless streams of motions at run time. This process is guided by an author who identifies (with help from our system) character poses that appear frequently in the corpus. Each such pose serves as a jump point at which any motion that enters can be followed by any motion that leaves, as shown in Figures 1 and 2. The result is a simple graph structure that allows clips to be connected into longer motions.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128502084","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 present a new method for completing missing parts caused by the removal of foreground or background elements from an image. Our goal is to synthesize a complete, visually plausible and coherent image. The visible parts of the image serve as a training set to infer the unknown parts. Our method iteratively approximates the unknown regions and composites adaptive image fragments into the image. Values of an inverse matte are used to compute a confidence map and a level set that direct an incremental traversal within the unknown area from high to low confidence. In each step, guided by a fast smooth approximation, an image fragment is selected from the most similar and frequent examples. As the selected fragments are composited, their likelihood increases along with the mean confidence of the image, until reaching a complete image. We demonstrate our method by completion of photographs and paintings.
{"title":"Fragment-based image completion","authors":"Iddo Drori, D. Cohen-Or, Y. Yeshurun","doi":"10.1145/1201775.882267","DOIUrl":"https://doi.org/10.1145/1201775.882267","url":null,"abstract":"We present a new method for completing missing parts caused by the removal of foreground or background elements from an image. Our goal is to synthesize a complete, visually plausible and coherent image. The visible parts of the image serve as a training set to infer the unknown parts. Our method iteratively approximates the unknown regions and composites adaptive image fragments into the image. Values of an inverse matte are used to compute a confidence map and a level set that direct an incremental traversal within the unknown area from high to low confidence. In each step, guided by a fast smooth approximation, an image fragment is selected from the most similar and frequent examples. As the selected fragments are composited, their likelihood increases along with the mean confidence of the image, until reaching a complete image. We demonstrate our method by completion of photographs and paintings.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116414674","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 acting-based animation system for creating and editing character animation at interactive speeds. Our system requires minimal training, typically under an hour, and is well suited for rapidly prototyping and creating expressive motion. A real-time motion-capture framework records the user's motions for simultaneous analysis and playback on a large screen. The animator's real-world, expressive motions are mapped into the character's virtual world. Visual feedback maintains a tight coupling between the animator and character. Complex motion is created by layering multiple passes of acting. We also introduce a novel motion-editing technique, which derives implicit relationships between the animator and character. The animator mimics some aspect of the character motion, and the system infers the association between features of the animator's motion and those of the character. The animator modifies the mimic by acting again, and the system maps the changes onto the character. We demonstrate our system with several examples and present the results from informal user studies with expert and novice animators.
{"title":"Layered acting for character animation","authors":"Mira Dontcheva, Gary D. Yngve, Zoran Popovic","doi":"10.1145/1201775.882285","DOIUrl":"https://doi.org/10.1145/1201775.882285","url":null,"abstract":"We introduce an acting-based animation system for creating and editing character animation at interactive speeds. Our system requires minimal training, typically under an hour, and is well suited for rapidly prototyping and creating expressive motion. A real-time motion-capture framework records the user's motions for simultaneous analysis and playback on a large screen. The animator's real-world, expressive motions are mapped into the character's virtual world. Visual feedback maintains a tight coupling between the animator and character. Complex motion is created by layering multiple passes of acting. We also introduce a novel motion-editing technique, which derives implicit relationships between the animator and character. The animator mimics some aspect of the character motion, and the system infers the association between features of the animator's motion and those of the character. The animator modifies the mimic by acting again, and the system maps the changes onto the character. We demonstrate our system with several examples and present the results from informal user studies with expert and novice animators.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125312015","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}
The traditional approach for parametrizing a surface involves cutting it into charts and mapping these piecewise onto a planar domain. We introduce a robust technique for directly parametrizing a genus-zero surface onto a spherical domain. A key ingredient for making such a parametrization practical is the minimization of a stretch-based measure, to reduce scale-distortion and thereby prevent undersampling. Our second contribution is a scheme for sampling the spherical domain using uniformly subdivided polyhedral domains, namely the tetrahedron, octahedron, and cube. We show that these particular semi-regular samplings can be conveniently represented as completely regular 2D grids, i.e. geometry images. Moreover, these images have simple boundary extension rules that aid many processing operations. Applications include geometry remeshing, level-of-detail, morphing, compression, and smooth surface subdivision.
{"title":"Spherical parametrization and remeshing","authors":"Emil Praun, Hugues Hoppe","doi":"10.1145/1201775.882274","DOIUrl":"https://doi.org/10.1145/1201775.882274","url":null,"abstract":"The traditional approach for parametrizing a surface involves cutting it into charts and mapping these piecewise onto a planar domain. We introduce a robust technique for directly parametrizing a genus-zero surface onto a spherical domain. A key ingredient for making such a parametrization practical is the minimization of a stretch-based measure, to reduce scale-distortion and thereby prevent undersampling. Our second contribution is a scheme for sampling the spherical domain using uniformly subdivided polyhedral domains, namely the tetrahedron, octahedron, and cube. We show that these particular semi-regular samplings can be conveniently represented as completely regular 2D grids, i.e. geometry images. Moreover, these images have simple boundary extension rules that aid many processing operations. Applications include geometry remeshing, level-of-detail, morphing, compression, and smooth surface subdivision.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125435313","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 a novel "sensation preserving" simplification algorithm for faster collision queries between two polyhedral objects in haptic rendering. Given a polyhedral model, we construct a multiresolution hierarchy using " filtered edge collapse", subject to constraints imposed by collision detection. The resulting hierarchy is then used to compute fast contact response for haptic display. The computation model is inspired by human tactual perception of contact information. We have successfully applied and demonstrated the algorithm on a time-critical collision query framework for haptically displaying complex object-object interaction. Compared to existing exact contact query algorithms, we observe noticeable performance improvement in update rates with little degradation in the haptic perception of contacts.
{"title":"Sensation preserving simplification for haptic rendering","authors":"M. Otaduy, M. Lin","doi":"10.1145/1201775.882305","DOIUrl":"https://doi.org/10.1145/1201775.882305","url":null,"abstract":"We introduce a novel \"sensation preserving\" simplification algorithm for faster collision queries between two polyhedral objects in haptic rendering. Given a polyhedral model, we construct a multiresolution hierarchy using \" filtered edge collapse\", subject to constraints imposed by collision detection. The resulting hierarchy is then used to compute fast contact response for haptic display. The computation model is inspired by human tactual perception of contact information. We have successfully applied and demonstrated the algorithm on a time-critical collision query framework for haptically displaying complex object-object interaction. Compared to existing exact contact query algorithms, we observe noticeable performance improvement in update rates with little degradation in the haptic perception of contacts.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131299876","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}
Using generic interpolation machinery based on solving Poisson equations, a variety of novel tools are introduced for seamless editing of image regions. The first set of tools permits the seamless importation of both opaque and transparent source image regions into a destination region. The second set is based on similar mathematical ideas and allows the user to modify the appearance of the image seamlessly, within a selected region. These changes can be arranged to affect the texture, the illumination, and the color of objects lying in the region, or to make tileable a rectangular selection.
{"title":"Poisson image editing","authors":"P. Pérez, Michel Gangnet, A. Blake","doi":"10.1145/1201775.882269","DOIUrl":"https://doi.org/10.1145/1201775.882269","url":null,"abstract":"Using generic interpolation machinery based on solving Poisson equations, a variety of novel tools are introduced for seamless editing of image regions. The first set of tools permits the seamless importation of both opaque and transparent source image regions into a destination region. The second set is based on similar mathematical ideas and allows the user to modify the appearance of the image seamlessly, within a selected region. These changes can be arranged to affect the texture, the illumination, and the color of objects lying in the region, or to make tileable a rectangular selection.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129527715","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}
D. DeCarlo, Adam Finkelstein, S. Rusinkiewicz, A. Santella
In this paper, we describe a non-photorealistic rendering system that conveys shape using lines. We go beyond contours and creases by developing a new type of line to draw: the suggestive contour. Suggestive contours are lines drawn on clearly visible parts of the surface, where a true contour would first appear with a minimal change in viewpoint. We provide two methods for calculating suggestive contours, including an algorithm that finds the zero crossings of the radial curvature. We show that suggestive contours can be drawn consistently with true contours, because they anticipate and extend them. We present a variety of results, arguing that these images convey shape more effectively than contour alone.
{"title":"Suggestive contours for conveying shape","authors":"D. DeCarlo, Adam Finkelstein, S. Rusinkiewicz, A. Santella","doi":"10.1145/1201775.882354","DOIUrl":"https://doi.org/10.1145/1201775.882354","url":null,"abstract":"In this paper, we describe a non-photorealistic rendering system that conveys shape using lines. We go beyond contours and creases by developing a new type of line to draw: the suggestive contour. Suggestive contours are lines drawn on clearly visible parts of the surface, where a true contour would first appear with a minimal change in viewpoint. We provide two methods for calculating suggestive contours, including an algorithm that finds the zero crossings of the radial curvature. We show that suggestive contours can be drawn consistently with true contours, because they anticipate and extend them. We present a variety of results, arguing that these images convey shape more effectively than contour alone.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133727272","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}
Robert D. Kalnins, Phillip L. Davidson, L. Markosian, Adam Finkelstein
We describe a way to render stylized silhouettes of animated 3D models with temporal coherence. Coherence is one of the central challenges for non-photorealistic rendering. It is especially difficult for silhouettes, because they may not have obvious correspondences between frames. We demonstrate various coherence effects for stylized silhouettes with a robust working system. Our method runs in real-time for models of moderate complexity, making it suitable for both interactive applications and offline animation.
{"title":"Coherent stylized silhouettes","authors":"Robert D. Kalnins, Phillip L. Davidson, L. Markosian, Adam Finkelstein","doi":"10.1145/1201775.882355","DOIUrl":"https://doi.org/10.1145/1201775.882355","url":null,"abstract":"We describe a way to render stylized silhouettes of animated 3D models with temporal coherence. Coherence is one of the central challenges for non-photorealistic rendering. It is especially difficult for silhouettes, because they may not have obvious correspondences between frames. We demonstrate various coherence effects for stylized silhouettes with a robust working system. Our method runs in real-time for models of moderate complexity, making it suitable for both interactive applications and offline animation.","PeriodicalId":314969,"journal":{"name":"ACM SIGGRAPH 2003 Papers","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132993972","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}
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