Improving the quality of an image increases the probability, speed and accuracy with which possible objects of interest can be located and identified. Image sharpening, in particular, can correct for soft focus and strengthen the outlines of objects thus improving the identification and segmentation both by automatic means and by man in the loop systems. Output pixel independence is ensured so that a GPU can be used to sharpen the pixels in parallel, achieving processing performance increases of 20--360 fold. This work provides a metric which can quantify the sharpness of an image and shows that the sharpness of live video can easily be doubled in realtime on commercial desktop computers without inducing excessive noise.
{"title":"A comparison of image sharpness metrics and real-time sharpening methods with GPU implementations","authors":"J. D. Villiers","doi":"10.1145/1811158.1811168","DOIUrl":"https://doi.org/10.1145/1811158.1811168","url":null,"abstract":"Improving the quality of an image increases the probability, speed and accuracy with which possible objects of interest can be located and identified. Image sharpening, in particular, can correct for soft focus and strengthen the outlines of objects thus improving the identification and segmentation both by automatic means and by man in the loop systems. Output pixel independence is ensured so that a GPU can be used to sharpen the pixels in parallel, achieving processing performance increases of 20--360 fold. This work provides a metric which can quantify the sharpness of an image and shows that the sharpness of live video can easily be doubled in realtime on commercial desktop computers without inducing excessive noise.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128907126","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 method for editing the LOD of quad meshes, which supports both adaptive refinement and adaptive coarsening. Starting at a base mesh, we generate a quad-dominant mesh which is consistent with the Catmull-Clark subdivision. Consistency is both topological and geometrical: an adaptively subdivided mesh coincides with the uniformly subdivided mesh wherever the level of subdivision is uniform, and the limit surface is the same. Subdivided meshes contain a majority of quad elements and a moderate amount of triangles and pentagons in the regions of transition across different levels of detail. Topological LOD editing is controlled with local conforming operators, which support both mesh refinement and mesh coarsening and work on a plain mesh without the need of cumbersome hierarchical data structures.
{"title":"Adaptive LOD editing of quad meshes","authors":"Daniele Panozzo, E. Puppo","doi":"10.1145/1811158.1811160","DOIUrl":"https://doi.org/10.1145/1811158.1811160","url":null,"abstract":"We present a method for editing the LOD of quad meshes, which supports both adaptive refinement and adaptive coarsening. Starting at a base mesh, we generate a quad-dominant mesh which is consistent with the Catmull-Clark subdivision. Consistency is both topological and geometrical: an adaptively subdivided mesh coincides with the uniformly subdivided mesh wherever the level of subdivision is uniform, and the limit surface is the same. Subdivided meshes contain a majority of quad elements and a moderate amount of triangles and pentagons in the regions of transition across different levels of detail. Topological LOD editing is controlled with local conforming operators, which support both mesh refinement and mesh coarsening and work on a plain mesh without the need of cumbersome hierarchical data structures.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"293 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122089451","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}
Aligning structures, often referred to as docking or registration, is frequently required in fields such as computer science, robotics and structural biology. The task of aligning the structures is usually automated, but due to noise and imprecision, the user often needs to evaluate the results before a final decision can be made. The solutions involved are of a multidimensional nature and normally densely populated. Therefore, some form of visualization is necessary, especially if users want to achieve higher level understanding, such as solution symmetry or clustering, from the data. We have developed a system that provides two views of the data. One view places focus on the orientation of the solutions and the other focuses on translations. Solutions within the views are crosslinked using various visual cues. Users are also able to apply various filters, intelligently reducing the solution set. We applied the visualization to data generated by the automated cryo-EM process of docking molecular structures into electron density maps. Current systems in this field only allow for visual representation of a single solution or a numerical list of the data. We evaluated the system through a multi-phase user study and found that the users were able to gain a better high-level understanding of the data, even in cases of relatively small solution sets.
{"title":"Visualization of solution sets from automated docking of molecular structures","authors":"J. V. Vuuren, M. Kuttel, J. Gain","doi":"10.1145/1811158.1811177","DOIUrl":"https://doi.org/10.1145/1811158.1811177","url":null,"abstract":"Aligning structures, often referred to as docking or registration, is frequently required in fields such as computer science, robotics and structural biology. The task of aligning the structures is usually automated, but due to noise and imprecision, the user often needs to evaluate the results before a final decision can be made. The solutions involved are of a multidimensional nature and normally densely populated. Therefore, some form of visualization is necessary, especially if users want to achieve higher level understanding, such as solution symmetry or clustering, from the data.\u0000 We have developed a system that provides two views of the data. One view places focus on the orientation of the solutions and the other focuses on translations. Solutions within the views are crosslinked using various visual cues. Users are also able to apply various filters, intelligently reducing the solution set. We applied the visualization to data generated by the automated cryo-EM process of docking molecular structures into electron density maps. Current systems in this field only allow for visual representation of a single solution or a numerical list of the data. We evaluated the system through a multi-phase user study and found that the users were able to gain a better high-level understanding of the data, even in cases of relatively small solution sets.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129280867","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}
Image registration forms the basis of many computer vision tasks. The Lucas-Kanade image registration algorithm is known to efficiently solve the sub-problem of rigid image registration. It is therefore often used in image stabilisation applications. This paper presents the details of a real-time implementation of the Lucas-Kanade image registration algorithm on a Graphics Processing Unit (GPU) using the OpenGL Shading Language (GLSL). The implementation is driven by a real world requirement to computationally stabilise the undulatory motion of an ocean-based wide area surveillance system.
{"title":"Implementation of the Lucas-Kanade image registration algorithm on a GPU for 3D computational platform stabilisation","authors":"B. Duvenhage, J. Delport, J. D. Villiers","doi":"10.1145/1811158.1811172","DOIUrl":"https://doi.org/10.1145/1811158.1811172","url":null,"abstract":"Image registration forms the basis of many computer vision tasks. The Lucas-Kanade image registration algorithm is known to efficiently solve the sub-problem of rigid image registration. It is therefore often used in image stabilisation applications. This paper presents the details of a real-time implementation of the Lucas-Kanade image registration algorithm on a Graphics Processing Unit (GPU) using the OpenGL Shading Language (GLSL). The implementation is driven by a real world requirement to computationally stabilise the undulatory motion of an ocean-based wide area surveillance system.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"9 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120992213","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}
In curve design it is often desirable to match G2 Hermite data with a pair of spirals. An existing method addresses this problem using cubics by first requiring the joint to be placed, and then matching tangents at the joint. It is now shown that an alternative method of first matching tangents, which then determine an interval along a line for placement of the joint, is more convenient and requires less computation.
{"title":"Cubic Bézier spiral segments for planar G2 curve design","authors":"D. Walton, D. Meek","doi":"10.1145/1811158.1811162","DOIUrl":"https://doi.org/10.1145/1811158.1811162","url":null,"abstract":"In curve design it is often desirable to match G2 Hermite data with a pair of spirals. An existing method addresses this problem using cubics by first requiring the joint to be placed, and then matching tangents at the joint. It is now shown that an alternative method of first matching tangents, which then determine an interval along a line for placement of the joint, is more convenient and requires less computation.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127818864","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}
R. Baxter, Zacharia Crumley, Rudolph Neeser, J. Gain
While the field of procedural content generation is growing, there has been somewhat less work on developing procedural methods to animate these models. We present a technique for generating procedural models of trees and buildings via formal grammars (L-Systems and wall grammars) that are ready to be animated using physical simulation. The grammars and their interpretations are augmented to provide direct control over the physical animation, by, for example, specifying object mass and the joint stiffness. Example animations produced by our system include trees swaying in a gentle wind or being rocked by a gale, and buildings collapsing, imploding or exploding. In user testing, we had test subjects (n = 20) compare our animations with video of trees and buildings undergoing similar effects, as well as with animations in games that they have played. Results show that our animations appear physically accurate with a few minor instances of unrealistic behaviour. Users considered the animations to be more realistic than those used in current video games.
{"title":"Automatic addition of physics components to procedural content","authors":"R. Baxter, Zacharia Crumley, Rudolph Neeser, J. Gain","doi":"10.1145/1811158.1811175","DOIUrl":"https://doi.org/10.1145/1811158.1811175","url":null,"abstract":"While the field of procedural content generation is growing, there has been somewhat less work on developing procedural methods to animate these models. We present a technique for generating procedural models of trees and buildings via formal grammars (L-Systems and wall grammars) that are ready to be animated using physical simulation. The grammars and their interpretations are augmented to provide direct control over the physical animation, by, for example, specifying object mass and the joint stiffness. Example animations produced by our system include trees swaying in a gentle wind or being rocked by a gale, and buildings collapsing, imploding or exploding. In user testing, we had test subjects (n = 20) compare our animations with video of trees and buildings undergoing similar effects, as well as with animations in games that they have played. Results show that our animations appear physically accurate with a few minor instances of unrealistic behaviour. Users considered the animations to be more realistic than those used in current video games.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114193588","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 proportion colour harmony model enhancing image aesthetics in terms of human colour perception. Given an arbitrary image, colours are modified to improve their proportion harmony. The proportion relationship between colours has been described in theories of colours but never proposed in computer graphics. Our model detects proportion harmony or the lack thereof harmony, proposes improvements verifying constraints defined by the user as well as different possibilities to recolor the image by shifting hues. Our technique is well-adapted to adjust the colour in an image, in a part of an image, image composition or a subset of colours depending on the user choices. Results show that our colour harmonization model allows the user to handle classical images such as photographs or drawings and paintings.
{"title":"Harmonic colorization using proportion contrast","authors":"C. Sauvaget, V. Boyer","doi":"10.1145/1811158.1811169","DOIUrl":"https://doi.org/10.1145/1811158.1811169","url":null,"abstract":"We present a proportion colour harmony model enhancing image aesthetics in terms of human colour perception. Given an arbitrary image, colours are modified to improve their proportion harmony. The proportion relationship between colours has been described in theories of colours but never proposed in computer graphics. Our model detects proportion harmony or the lack thereof harmony, proposes improvements verifying constraints defined by the user as well as different possibilities to recolor the image by shifting hues. Our technique is well-adapted to adjust the colour in an image, in a part of an image, image composition or a subset of colours depending on the user choices. Results show that our colour harmonization model allows the user to handle classical images such as photographs or drawings and paintings.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"211 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126096764","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}
From the literature, it is known that backward polygon beam tracing and other light volume methods are well suited to gather path coherency from specular scattering surfaces. This is of course useful for modelling and efficiently simulating caustics (LS+DE paths). This paper generalises backward polygon beam tracing to also model glossy scattering surfaces. To this end the details of a backward polygon beam tracing model and implementation of source-to-glossy-to-diffuse light transport (LG+DE) paths are researched.
{"title":"Exploring the use of glossy light volumes for interactive global illumination","authors":"B. Duvenhage, K. Bouatouch, D. Kourie","doi":"10.1145/1811158.1811181","DOIUrl":"https://doi.org/10.1145/1811158.1811181","url":null,"abstract":"From the literature, it is known that backward polygon beam tracing and other light volume methods are well suited to gather path coherency from specular scattering surfaces. This is of course useful for modelling and efficiently simulating caustics (LS+DE paths). This paper generalises backward polygon beam tracing to also model glossy scattering surfaces. To this end the details of a backward polygon beam tracing model and implementation of source-to-glossy-to-diffuse light transport (LG+DE) paths are researched.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124596806","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}
Jörg Stöcklein, Patrick Pogscheba, C. Geiger, V. Paelke
Virtual prototyping has become an established design tool in complex interdisciplinary development processes using state-of-the-art virtual reality techniques. Due to numerous benefits virtual prototyping has seen increasing acceptance in recent years, especially in the development of systems that involve complex interactions between components or require the integration of newly developed hardware. Mixed reality, considered as an extension to VR, has high potential to support the development of complex systems that operate in a real world environment even further. In this paper we demonstrate that the principles of mixed reality prototyping can also be effectively applied to the development of complex systems if a structured process is defined and supported by a proper software framework. In our paper we present a system that supports an iterative approach to prototype complex dynamical systems. Using this approach allows the designer to seamlessly progress from an initial virtual prototype to the final system along the mixed reality continuum. We describe MiReAS, a mixed reality software framework that supports an iterative design evolution with arbitrary combinations of real and virtual elements. The use of the system is demonstrated by the development of interaction techniques and control strategies for an unmanned aerial vehicle.
{"title":"MiReAS: a mixed reality software framework for iterative prototyping of control strategies for an indoor airship","authors":"Jörg Stöcklein, Patrick Pogscheba, C. Geiger, V. Paelke","doi":"10.1145/1811158.1811164","DOIUrl":"https://doi.org/10.1145/1811158.1811164","url":null,"abstract":"Virtual prototyping has become an established design tool in complex interdisciplinary development processes using state-of-the-art virtual reality techniques. Due to numerous benefits virtual prototyping has seen increasing acceptance in recent years, especially in the development of systems that involve complex interactions between components or require the integration of newly developed hardware. Mixed reality, considered as an extension to VR, has high potential to support the development of complex systems that operate in a real world environment even further. In this paper we demonstrate that the principles of mixed reality prototyping can also be effectively applied to the development of complex systems if a structured process is defined and supported by a proper software framework. In our paper we present a system that supports an iterative approach to prototype complex dynamical systems. Using this approach allows the designer to seamlessly progress from an initial virtual prototype to the final system along the mixed reality continuum. We describe MiReAS, a mixed reality software framework that supports an iterative design evolution with arbitrary combinations of real and virtual elements. The use of the system is demonstrated by the development of interaction techniques and control strategies for an unmanned aerial vehicle.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130090103","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}
Smell is a key human sense. In the real world, smell plays a leading role in helping us appreciate an environment, for example the smell of fresh coffee, or the dead body. High-fidelity virtual environments are being increasingly used as an accurate representation of the real world for a wide variety of applications, including training, phobia treatment and virtual archeology. This paper compares the diffusion and perception of smell in real and virtual environments. Although airflow can be computed within a virtual environment using, for example a computational fluid dynamic simulator, the results do not necessarily predict how smell may be perceived in the real-world. Virtual smell needs to take into account the type of smell being considered and how humans may perceive this smell.
{"title":"Virtual smell: authentic smell diffusion in virtual environments","authors":"Belma Ramic-Brkic, A. Chalmers","doi":"10.1145/1811158.1811166","DOIUrl":"https://doi.org/10.1145/1811158.1811166","url":null,"abstract":"Smell is a key human sense. In the real world, smell plays a leading role in helping us appreciate an environment, for example the smell of fresh coffee, or the dead body. High-fidelity virtual environments are being increasingly used as an accurate representation of the real world for a wide variety of applications, including training, phobia treatment and virtual archeology. This paper compares the diffusion and perception of smell in real and virtual environments. Although airflow can be computed within a virtual environment using, for example a computational fluid dynamic simulator, the results do not necessarily predict how smell may be perceived in the real-world. Virtual smell needs to take into account the type of smell being considered and how humans may perceive this smell.","PeriodicalId":325699,"journal":{"name":"International Conference on Computer Graphics, Virtual Reality, Visualisation and Interaction in Africa","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127127909","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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