[ { "id": "CADIK-2008-EHD", "type_id": "journalpaper_notalk", "tu_id": null, "repositum_id": null, "title": "Evaluation of HDR Tone Mapping Methods Using Essential Perceptual Attributes", "date": "2008-06", "abstract": "The problem of reproducing high dynamic range images on devices with restricted dynamic range has gained a lot of interest in the computer graphics community. There exist various approaches to this issue, which span several research areas including computer graphics, image processing, color vision, physiological aspects, etc. These approaches assume a thorough knowledge of both the objective and subjective attributes of an image. However, no comprehensive overview and analysis of such attributes has been published so far.\n\nIn this contribution, we present an overview about the effects of basic image attributes in HDR tone mapping. Furthermore, we propose a scheme of relationships between these attributes, leading to the definition of an overall image quality measure. We present results of subjective psychophysical experiments that we have performed to prove the proposed relationship scheme. Moreover, we also present an evaluation of existing tone mapping methods (operators) with regard to these attributes. Finally, the execution of with-reference and without a real reference perceptual experiments gave us the opportunity to relate the obtained subjective results.\n\nOur effort is not just useful to get into the tone mapping field or when implementing a tone mapping method, but it also sets the stage for well-founded quality comparisons between tone mapping methods. By providing good definitions of the different attributes, user-driven or fully automatic comparisons are made possible.\n", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 1600, "image_height": 1200, "name": "CADIK-2008-EHD-.bmp", "type": "image/x-ms-bmp", "size": 5760054, "path": "Publication:CADIK-2008-EHD", "url": "https://www.cg.tuwien.ac.at/research/publications/2008/CADIK-2008-EHD/CADIK-2008-EHD-.bmp", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2008/CADIK-2008-EHD/CADIK-2008-EHD-:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 635, 193, 177, 191 ], "issn": "0097-8493", "journal": "Computers & Graphics", "number": "3", "pages_from": "330", "pages_to": "349", "volume": "32", "research_areas": [ "Rendering" ], "keywords": [ "high dynamic range", "tone mapping operators", "tone mapping evaluation", "image attributes" ], "weblinks": [], "files": [ { "description": null, "filetitle": "", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 1600, "image_height": 1200, "name": "CADIK-2008-EHD-.bmp", "type": "image/x-ms-bmp", "size": 5760054, "path": "Publication:CADIK-2008-EHD", "url": "https://www.cg.tuwien.ac.at/research/publications/2008/CADIK-2008-EHD/CADIK-2008-EHD-.bmp", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2008/CADIK-2008-EHD/CADIK-2008-EHD-:thumb{{size}}.png" }, { "description": null, "filetitle": "Preprint", "main_file": true, "use_in_gallery": false, "access": "public", "name": "CADIK-2008-EHD-Preprint.pdf", "type": "application/pdf", "size": 2159163, "path": "Publication:CADIK-2008-EHD", "url": "https://www.cg.tuwien.ac.at/research/publications/2008/CADIK-2008-EHD/CADIK-2008-EHD-Preprint.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2008/CADIK-2008-EHD/CADIK-2008-EHD-Preprint:thumb{{size}}.png" } ], "projects_workgroups": [ "Treelumination" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2008/CADIK-2008-EHD/", "__class": "Publication" }, { "id": "neumann-2006-gamma", "type_id": "journalpaper_notalk", "tu_id": null, "repositum_id": null, "title": "Accurate Display Gamma Functions based on Human Observation", "date": "2007", "abstract": "This paper describes an accurate method to obtain the\nTone Reproduction Curve (TRC) of display devices without using\na measurement device. It is an improvement of an existing technique\nbased on human observation, solving its problem of numerical instability\nand resulting in functions in log--log scale which correspond better\nto the nature of display devices.\nWe demonstrate the effiency of our technique on different monitor\ntechnologies, comparing it with direct measurements using a\nspectrophotometer.", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": false, "access": "public", "image_width": 300, "image_height": 280, "name": "neumann-2006-gamma-image.png", "type": "image/png", "size": 6781, "path": "Publication:neumann-2006-gamma", "url": "https://www.cg.tuwien.ac.at/research/publications/2007/neumann-2006-gamma/neumann-2006-gamma-image.png", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2007/neumann-2006-gamma/neumann-2006-gamma-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 232, 191, 177, 222, 190 ], "issn": "0361-2317", "journal": "Color Research & Applications", "note": "2006 angenommen, 2007 erschienen", "number": "4", "pages_from": "310", "pages_to": "319", "volume": "32", "research_areas": [ "Rendering" ], "keywords": [ "Generalized Gamma Function", "Colour Reproduction", "Display Measurement", "Human Visual System", "Spatial Vision" ], "weblinks": [], "files": [ { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": false, "access": "public", "image_width": 300, "image_height": 280, "name": "neumann-2006-gamma-image.png", "type": "image/png", "size": 6781, "path": "Publication:neumann-2006-gamma", "url": "https://www.cg.tuwien.ac.at/research/publications/2007/neumann-2006-gamma/neumann-2006-gamma-image.png", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2007/neumann-2006-gamma/neumann-2006-gamma-image:thumb{{size}}.png" }, { "description": null, "filetitle": "paper", "main_file": false, "use_in_gallery": false, "access": "public", "name": "neumann-2006-gamma-paper.pdf", "type": "application/pdf", "size": 457864, "path": "Publication:neumann-2006-gamma", "url": "https://www.cg.tuwien.ac.at/research/publications/2007/neumann-2006-gamma/neumann-2006-gamma-paper.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2007/neumann-2006-gamma/neumann-2006-gamma-paper:thumb{{size}}.png" } ], "projects_workgroups": [ "realreflect" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2007/neumann-2006-gamma/", "__class": "Publication" }, { "id": "CADIK-2006-IAQ", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Image Attributes and Quality for Evaluation of Tone Mapping Operators", "date": "2006-10", "abstract": "The problem of reproducing high dynamic range images\non devices with restricted dynamic range has gained a lot\nof interest in the computer graphics community. There exist\nvarious approaches to this issue, which span several research\nareas including computer graphics, image processing,\ncolor science, physiology, neurology, psychology, etc.\nThese approaches assume a thorough knowledge of both the\nobjective and subjective attributes of an image. However,\nno comprehensive overview and analysis of such attributes\nhas been published so far.\nIn this paper, we present an overview of image quality\nattributes of different tone mapping methods. Furthermore,\nwe propose a scheme of relationships between these\nattributes, leading to the definition of an overall image quality\nmeasure. We present results of subjective psychophysical\ntests that we have performed to prove the proposed relationship\nscheme. We also present the evaluation of existing tone\nmapping methods with regard to these attributes.\nOur effort is not just useful to get into the tone mapping\nfield or when implementing a tone mapping operator, but\nit also sets the stage for well-founded quality comparisons\nbetween tone mapping operators. By providing good definitions\nof the different attributes, user-driven or fully automatic\ncomparisons are made possible at all.", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "", "main_file": false, "use_in_gallery": false, "access": "public", "image_width": 600, "image_height": 451, "name": "CADIK-2006-IAQ-.png", "type": "image/png", "size": 276313, "path": "Publication:CADIK-2006-IAQ", "url": "https://www.cg.tuwien.ac.at/research/publications/2006/CADIK-2006-IAQ/CADIK-2006-IAQ-.png", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2006/CADIK-2006-IAQ/CADIK-2006-IAQ-:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 635, 193, 177, 191 ], "booktitle": "Proceedings of Pacific Graphics 2006 (14th Pacific Conference on Computer Graphics and Applications)", "date_from": "2006-10-11", "date_to": "2006-10-13", "lecturer": [ 635 ], "location": "Taipe, Taiwan", "pages_from": "35", "pages_to": "44", "publisher": "National Taiwan University Press", "research_areas": [ "Rendering" ], "keywords": [ "tone mapping evaluation", "tone mapping", "high-dynamic range images" ], "weblinks": [], "files": [ { "description": null, "filetitle": "", "main_file": false, "use_in_gallery": false, "access": "public", "image_width": 600, "image_height": 451, "name": "CADIK-2006-IAQ-.png", "type": "image/png", "size": 276313, "path": "Publication:CADIK-2006-IAQ", "url": "https://www.cg.tuwien.ac.at/research/publications/2006/CADIK-2006-IAQ/CADIK-2006-IAQ-.png", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2006/CADIK-2006-IAQ/CADIK-2006-IAQ-:thumb{{size}}.png" }, { "description": null, "filetitle": "Paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "CADIK-2006-IAQ-Paper.pdf", "type": "application/pdf", "size": 477797, "path": "Publication:CADIK-2006-IAQ", "url": "https://www.cg.tuwien.ac.at/research/publications/2006/CADIK-2006-IAQ/CADIK-2006-IAQ-Paper.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2006/CADIK-2006-IAQ/CADIK-2006-IAQ-Paper:thumb{{size}}.png" } ], "projects_workgroups": [ "Treelumination" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2006/CADIK-2006-IAQ/", "__class": "Publication" }, { "id": "TR-186-2-05-05", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Computational Color Harmony based on Coloroid System", "date": "2005-06", "abstract": "The paper presents experimentally based rules and methods creating harmonic color sets. Firstly, dichromatic rules will be presented which concern color harmony relationships of only two hues. For an arbitrarily given hue pair, we define the textit{just harmonic} saturation values, resulting in just harmonic color pairs. These values express the fuzzy border between harmony and disharmony regions by a single scalar, most appropriately. \n\nSecondly, the value of harmony will be defined corresponding to the textit{contrast of lightness}, i.e. the difference of perceptual lightness values. \nThirdly, we formulate the harmony value of the textit{saturation contrast}, depending on hue and lightness. Results of these investigations form a basis for a unified, \ncoherent dichromatic harmony formula as well as for analysis of polychromatic color harmony. \n\nIntroduced color harmony rules are based on Coloroid, which is one of the $5-6$ main color-order systems and furthermore it is an textit{aesthetically uniform} continuous color space. \nColoroid has simple closed forward and backward transformation formulas with the color space of $CIE~XYZ$. It relies on a huge number of observations and experiments, and it is a very suitable tool of color dynamics for describing aesthetical relationships. \nIt had supported also numerous color plans of great architectural projects \nhaving been realized in the practice. \nThe experimental data and information to be retrieved from them are \njust partly processed and published so far. Our article utilizes a 'slice' of this database, \ntogether with additional complementary observations. \nThis paper is an issue of a planned series of articles, dealing with rules and coherences of color harmony based on the Coloroid system. ", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 443, "image_height": 458, "name": "TR-186-2-05-05-image.jpg", "type": "image/jpeg", "size": 53934, "path": "Publication:TR-186-2-05-05", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/TR-186-2-05-05/TR-186-2-05-05-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/TR-186-2-05-05/TR-186-2-05-05-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 496, 232 ], "number": "TR-186-2-05-05", "research_areas": [], "keywords": [ "Color Dynamics", "Computational Aesthetics", "Coloroid", "Color Order System", "Color Harmony", "Environmental Color Design" ], "weblinks": [], "files": [ { "description": null, "filetitle": "Computational Color Harmony", "main_file": true, "use_in_gallery": false, "access": "public", "preview_image_width": 600, "preview_image_height": 600, "name": "TR-186-2-05-05-Computational Color Harmony.pdf", "type": "application/pdf", "size": 7263941, "path": "Publication:TR-186-2-05-05", "preview_name": "TR-186-2-05-05-Computational Color Harmony:preview.png", "preview_type": "image/jpeg", "preview_size": 227752, "url": "https://www.cg.tuwien.ac.at/research/publications/2005/TR-186-2-05-05/TR-186-2-05-05-Computational Color Harmony.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/TR-186-2-05-05/TR-186-2-05-05-Computational Color Harmony:thumb{{size}}.png" }, { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 443, "image_height": 458, "name": "TR-186-2-05-05-image.jpg", "type": "image/jpeg", "size": 53934, "path": "Publication:TR-186-2-05-05", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/TR-186-2-05-05/TR-186-2-05-05-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/TR-186-2-05-05/TR-186-2-05-05-image:thumb{{size}}.png" } ], "projects_workgroups": [ "rend" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2005/TR-186-2-05-05/", "__class": "Publication" }, { "id": "lneumann-2005-cch", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Computational Color Harmony based on Coloroid System", "date": "2005-05", "abstract": "This paper presents experimentally based rules and methods for the creation of harmonic color sets. First, dichromatic\r\nrules are presented which concern the harmony relationships of two hues. For an arbitrarily given hue pair,\r\nwe de\u0002ne the just harmonic saturation values, resulting in minimally harmonic color pairs. These values express\r\nthe fuzzy border between harmony and disharmony regions using a single scalar.\r\nSecond, the value of harmony is de\u0002ned corresponding to the contrast of lightness, i.e. the difference of perceptual\r\nlightness values. Third, we formulate the harmony value of the saturation contrast, depending on hue and lightness.\r\nThe results of these investigations form a basis for a uni\u0002ed, coherent dichromatic harmony formula as well as for\r\nanalysis of polychromatic color harmony.\r\nIntroduced color harmony rules are based on Coloroid, which is one of the 5", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 177, "image_height": 169, "name": "lneumann-2005-cch-image.jpg", "type": "image/jpeg", "size": 32185, "path": "Publication:lneumann-2005-cch", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cch/lneumann-2005-cch-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cch/lneumann-2005-cch-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 496, 232 ], "booktitle": "Computational Aesthetics in Graphics, Visualization and Imaging 2005", "date_from": "2005-05-18", "date_to": "2005-05-20", "editor": "L. Neumann, M. Sbert, B. Gooch, W. Purgathofer", "isbn": "3905673274", "lecturer": [ 177 ], "location": "Girona, Spain", "pages_from": "231", "pages_to": "240", "research_areas": [], "keywords": [], "weblinks": [], "files": [ { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 177, "image_height": 169, "name": "lneumann-2005-cch-image.jpg", "type": "image/jpeg", "size": 32185, "path": "Publication:lneumann-2005-cch", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cch/lneumann-2005-cch-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cch/lneumann-2005-cch-image:thumb{{size}}.png" }, { "description": null, "filetitle": "PDF", "main_file": true, "use_in_gallery": false, "access": "public", "name": "lneumann-2005-cch-PDF.pdf", "type": "application/pdf", "size": 14403655, "path": "Publication:lneumann-2005-cch", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cch/lneumann-2005-cch-PDF.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cch/lneumann-2005-cch-PDF:thumb{{size}}.png" } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cch/", "__class": "Publication" }, { "id": "lneumann-2005-cst", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Color Style Transfer Techniques using Hue, Lightness and Saturation Histogram Matching", "date": "2005-05", "abstract": "We present new methods which transfer the color style of a source image into an arbitrary given target image\r\nhaving a different 3D color distribution. The color transfer has a high importance ensuring a wide area of applications\r\nfrom artistic transformation of the color atmosphere of images until different scientific visualizations using\r\nspecial gamut mappings.\r\nOur technique use a permissive, or optionally strict, 3D histogram matching, similarly to the sampling of multivariable\r\nfunctions applying a sequential chain of conditional probability density functions. We work by order\r\nof hue, hue dependent lightness and from both dependent saturation histograms of source and target images, respectively.\r\nWe apply different histogram transformations, like smoothing or contrast limitation, in order to avoid\r\nsome unexpected high gradients and other artifacts. Furthermore, we use dominance suppression optionally, by\r\napplying sub-linear functions for the histograms in order to get well balanced color distributions, or an overall\r\nappearance reflecting the memory color distribution better. Forward and inverse operations on the corresponding\r\ncumulative histograms ensure a continuous mapping of perceptual attributes correlating to limited derivatives.\r\nSampling an appropriate fraction of the pixels and using perceptually accurate and continuous histograms with\r\nminimal size as well as other gems make this method robust and fast.", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 198, "image_height": 197, "name": "lneumann-2005-cst-image.jpg", "type": "image/jpeg", "size": 37923, "path": "Publication:lneumann-2005-cst", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cst/lneumann-2005-cst-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cst/lneumann-2005-cst-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 232 ], "booktitle": "Computational Aesthetics in Graphics, Visualization and Imaging 2005", "date_from": "2005-05-18", "date_to": "2005-05-20", "editor": "L. Neumann, M. Sbert, B. Gooch, W. Purgathofer", "isbn": "3905673274", "lecturer": [ 177 ], "location": "Girona, Spain", "pages_from": "111", "pages_to": "122", "research_areas": [], "keywords": [], "weblinks": [], "files": [ { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 198, "image_height": 197, "name": "lneumann-2005-cst-image.jpg", "type": "image/jpeg", "size": 37923, "path": "Publication:lneumann-2005-cst", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cst/lneumann-2005-cst-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cst/lneumann-2005-cst-image:thumb{{size}}.png" }, { "description": null, "filetitle": "PDF", "main_file": true, "use_in_gallery": false, "access": "public", "name": "lneumann-2005-cst-PDF.pdf", "type": "application/pdf", "size": 29728853, "path": "Publication:lneumann-2005-cst", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cst/lneumann-2005-cst-PDF.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cst/lneumann-2005-cst-PDF:thumb{{size}}.png" } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2005/lneumann-2005-cst/", "__class": "Publication" }, { "id": "matkovic-2005-glo", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Global Contrast Factor-a New Approach to Image Contrast", "date": "2005-05", "abstract": "Contrast in image processing is usually de\u0002ned as a ratio between the darkest and the brightest spots of an image.\r\nIn this paper we introduce a different contrast de\u0002nition. The newly introduced Global Contrast Factor (GCF)\r\ncorresponds closer to the human perception of contrast. GCF uses contrasts at various resolution levels in order\r\nto compute overall contrast. Experiments were conducted in order to \u0002nd weight factors needed to calculate GCF.\r\nGCF measures richness of detail as perceived by a human observer, and as such can be used in various application\r\nareas like rendering, tone mapping, volume visualization, and lighting design", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 210, "image_height": 327, "name": "matkovic-2005-glo-image.jpg", "type": "image/jpeg", "size": 40112, "path": "Publication:matkovic-2005-glo", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/matkovic-2005-glo/matkovic-2005-glo-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/matkovic-2005-glo/matkovic-2005-glo-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 235, 177, 232, 26, 190 ], "booktitle": "Computational Aesthetics in Graphics, Visualization and Imaging 2005", "date_from": "2005-05-18", "date_to": "2005-05-20", "editor": "L. Neumann, M. Sbert, B. Gooch, W. Purgathofer", "isbn": "3905673274", "lecturer": [ 190 ], "location": "Girona, Spain", "pages_from": "159", "pages_to": "168", "publisher": "Eurographics Association", "research_areas": [], "keywords": [], "weblinks": [], "files": [ { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 210, "image_height": 327, "name": "matkovic-2005-glo-image.jpg", "type": "image/jpeg", "size": 40112, "path": "Publication:matkovic-2005-glo", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/matkovic-2005-glo/matkovic-2005-glo-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/matkovic-2005-glo/matkovic-2005-glo-image:thumb{{size}}.png" }, { "description": null, "filetitle": "PDF", "main_file": true, "use_in_gallery": false, "access": "public", "name": "matkovic-2005-glo-PDF.pdf", "type": "application/pdf", "size": 1339337, "path": "Publication:matkovic-2005-glo", "url": "https://www.cg.tuwien.ac.at/research/publications/2005/matkovic-2005-glo/matkovic-2005-glo-PDF.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2005/matkovic-2005-glo/matkovic-2005-glo-PDF:thumb{{size}}.png" } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2005/matkovic-2005-glo/", "__class": "Publication" }, { "id": "purgathofer-2005-ca", "type_id": "book", "tu_id": null, "repositum_id": null, "title": "Computational Aesthetics 2005", "date": "2005", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 207, 596, 190 ], "isbn": "3905673274", "pages": "249", "publisher": "Eurographics Association", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2005/purgathofer-2005-ca/", "__class": "Publication" }, { "id": "Neumann-2004-HOB", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Human Observation Based Generalized Gamma Functions", "date": "2004-12", "abstract": "This paper describes an accurate method to obtain the\nTone Reproduction Curve (TRC) of display devices without using\na measurement device. It is an improvement of an existing technique\nbased on human observation, solving its problem of numerical instability\nand resulting in functions in log--log scale which correspond better\nto the nature of display devices.\nWe demonstrate the effiency of our technique on different monitor\ntechnologies, comparing it with direct measurements using a\nspectrophotometer.", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-2004-HOB-.pdf", "type": "application/pdf", "size": 205123, "path": "Publication:Neumann-2004-HOB", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neumann-2004-HOB/Neumann-2004-HOB-.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neumann-2004-HOB/Neumann-2004-HOB-:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 232, 191, 177, 222, 190 ], "number": "TR-186-2-04-13", "research_areas": [], "keywords": [ "Display Measurement", "Human Visual System", "Spatial Vision" ], "weblinks": [], "files": [ { "description": null, "filetitle": "", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-2004-HOB-.pdf", "type": "application/pdf", "size": 205123, "path": "Publication:Neumann-2004-HOB", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neumann-2004-HOB/Neumann-2004-HOB-.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neumann-2004-HOB/Neumann-2004-HOB-:thumb{{size}}.png" } ], "projects_workgroups": [ "realreflect" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neumann-2004-HOB/", "__class": "Publication" }, { "id": "Neum04Hig", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "High-resolution Depth and Reflectance Map Estimation in Underwater Imaging", "date": "2004-12", "abstract": "This paper describes \r\na novel technique to simultaneously determining the threedimensional\r\ngeometry and reflectance map of a scene in underwater\r\nimaging. Underwater light is affected\r\nby an exponential wavelenght-dependent absorption\r\nand undesired scattering effects. These special conditions\r\nmake image and video processing a difficult task in participating\r\nmedia. It is shown how to use this disturbing\r\nabsorption effect to find a new way to accurately estimate\r\nthe scene depth-map and multispectral reflectivities.\r\nThe process requires the acquisition of a multispectral image\r\nof the underwater scenario with the appropriate camera\r\nand lightsource arrangement. The algorithm has been tested\r\non several synthetic images for different noise levels. The\r\npromising results show that the technique provides accurate\r\nand stable results.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 460, 461, 232 ], "number": "TR-186-2-04-14", "research_areas": [], "keywords": [ "Underwater Imaging", "Depth Map" ], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04Hig/", "__class": "Publication" }, { "id": "neumann-2004-ipm", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Interactive Perception Based Model for Characterization of Display device", "date": "2004-01", "abstract": "This paper describes a simple to use, yet accurate way to obtain the Tone Reproduction Curve (TRC) of display devices without the use of a measurement device. Human vision is used to compare a series of dithered color patches against interactively changeable homogeneously colored display areas. Results comparing this method with spectrophotometer measurements are given for three monitors.", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 300, "image_height": 300, "name": "neumann-2004-ipm-image.jpg", "type": "image/jpeg", "size": 8374, "path": "Publication:neumann-2004-ipm", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/neumann-2004-ipm/neumann-2004-ipm-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/neumann-2004-ipm/neumann-2004-ipm-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 232, 191, 222, 177, 190 ], "booktitle": "Color Imaging IX: Processing, Hardcopy, and Applications IX", "isbn": "0819451967", "location": "San Jose, California, USA", "organization": "IST&SPIE", "research_areas": [], "keywords": [ "Display Measurement", "Human Visual System" ], "weblinks": [], "files": [ { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 300, "image_height": 300, "name": "neumann-2004-ipm-image.jpg", "type": "image/jpeg", "size": 8374, "path": "Publication:neumann-2004-ipm", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/neumann-2004-ipm/neumann-2004-ipm-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/neumann-2004-ipm/neumann-2004-ipm-image:thumb{{size}}.png" }, { "description": null, "filetitle": "Interactive Perception Based Display Characterization", "main_file": true, "use_in_gallery": false, "access": "public", "name": "neumann-2004-ipm-Interactive Perception Based Display Characterization.pdf", "type": "application/pdf", "size": 479599, "path": "Publication:neumann-2004-ipm", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/neumann-2004-ipm/neumann-2004-ipm-Interactive Perception Based Display Characterization.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/neumann-2004-ipm/neumann-2004-ipm-Interactive Perception Based Display Characterization:thumb{{size}}.png" } ], "projects_workgroups": [ "realreflect" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2004/neumann-2004-ipm/", "__class": "Publication" }, { "id": "Neum04GCM", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Gamut Clipping and Mapping based on Coloroid System", "date": "2004", "abstract": "The paper presents novel techniques based on the Coloroid color system which hitherto has not been applied to gamut mapping. The introduced methods described are hue preserving and use three gravity centers in a hue-dependent way. Two of the gravity centers are shifted toward the direction of ‘negative saturation’, and can be used for regions of bright and dark colors, while a third gravity center is used for saturated colors. \r\nAfter a short survey of gamut mapping an introduction to the Coloroid describes concisely its features and formulas. Then a simple color clipping rule is presented applicable to any rendering applications. A gamut mapping method will be defined mapping from a generic input image to an RGB display. Other variations of the method describe RGB-CYMK transformation and also cross-media mapping for known input and output gamut boundaries. \r\nThe introduced methods apply hue and chroma dependent lightness compression. They can be applied in realistic computer graphics and digital photography as well as in printing technologies. They are straightforward to implement and have low computational costs.", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 600, "image_height": 600, "name": "Neum04GCM-image.jpg", "type": "image/jpeg", "size": 93650, "path": "Publication:Neum04GCM", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04GCM/Neum04GCM-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04GCM/Neum04GCM-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 232 ], "booktitle": "Proceedings of Second European Conference on Colour in Graphics, Imaging and Vision", "pages_from": "548", "pages_to": "555", "research_areas": [], "keywords": [ "Coloroid Color System", "Gamut Clipping", "Gamut Mapping", "Human Perception" ], "weblinks": [], "files": [ { "description": null, "filetitle": "Gamut Clipping and Mapping", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neum04GCM-Gamut Clipping and Mapping.pdf", "type": "application/pdf", "size": 434136, "path": "Publication:Neum04GCM", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04GCM/Neum04GCM-Gamut Clipping and Mapping.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04GCM/Neum04GCM-Gamut Clipping and Mapping:thumb{{size}}.png" }, { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 600, "image_height": 600, "name": "Neum04GCM-image.jpg", "type": "image/jpeg", "size": 93650, "path": "Publication:Neum04GCM", "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04GCM/Neum04GCM-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04GCM/Neum04GCM-image:thumb{{size}}.png" } ], "projects_workgroups": [ "realreflect" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2004/Neum04GCM/", "__class": "Publication" }, { "id": "neumann-2003-color", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Color Appearance in Multispectral Radiosity", "date": "2003", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 418, "image_height": 395, "name": "neumann-2003-color-image.jpg", "type": "image/jpeg", "size": 36189, "path": "Publication:neumann-2003-color", "url": "https://www.cg.tuwien.ac.at/research/publications/2003/neumann-2003-color/neumann-2003-color-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2003/neumann-2003-color/neumann-2003-color-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 457, 232, 207 ], "booktitle": "Proceedings on the 2nd Hungarian Computergraphics and Geometry Conference", "editor": "L. Szirmay-Kalos, G. Renner", "isbn": "9634207669", "pages_from": "183", "pages_to": "194", "research_areas": [], "keywords": [], "weblinks": [], "files": [ { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 418, "image_height": 395, "name": "neumann-2003-color-image.jpg", "type": "image/jpeg", "size": 36189, "path": "Publication:neumann-2003-color", "url": "https://www.cg.tuwien.ac.at/research/publications/2003/neumann-2003-color/neumann-2003-color-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2003/neumann-2003-color/neumann-2003-color-image:thumb{{size}}.png" }, { "description": null, "filetitle": "PDF", "main_file": true, "use_in_gallery": false, "access": "public", "name": "neumann-2003-color-PDF.pdf", "type": "application/pdf", "size": 485386, "path": "Publication:neumann-2003-color", "url": "https://www.cg.tuwien.ac.at/research/publications/2003/neumann-2003-color/neumann-2003-color-PDF.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2003/neumann-2003-color/neumann-2003-color-PDF:thumb{{size}}.png" } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2003/neumann-2003-color/", "__class": "Publication" }, { "id": "neumann-2002-globcon", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "The Global Contrast Factor", "date": "2002-11", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 235, 190 ], "booktitle": "Seminar on Computer Graphics and Visualization", "editor": "E. Carling, A. Hast", "location": "Gavle, Sweden", "organization": "University of Gavle", "pages_from": "108", "pages_to": "119", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2002/neumann-2002-globcon/", "__class": "Publication" }, { "id": "Csebfalvi-2002-SBICG", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Smooth Shape-Based Interpolation using the Conjugate Gradient Method", "date": "2002-08", "abstract": "In this paper a novel technique for smooth shape-based interpolation of volume data\r\nis introduced.\r\nPreviously simple linear interpolation of signed\r\ndistance maps has been used in practice. As it will be shown, this approach\r\nresults in artifacts, since sharp edges appear along the original slices.\r\nIn order to obtain a smooth 3D implicit function generated\r\nby interpolating 2D distance maps, we use a global interpolation method instead of a\r\nhigher order local technique. The global curvature of the implicit function representing\r\nan isosurface is minimized using an iterative conjugate gradient method.\r\nBecause of the iterative approach the user can easily control the trade-off between\r\nthe smoothness of the isosurface and the computational cost of the refinement.\r\nAs opposed to previous techniques, like variational interpolation, our method can\r\ngenerate a reasonably good approximation of the ideal solution in a significantly\r\n shorter time.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 233, 177, 162, 166 ], "number": "TR-186-2-02-10", "pages_from": "1", "pages_to": "8", "research_areas": [], "keywords": [ "shape-based interpolation", "conjugate gradient method", "volume rendering" ], "weblinks": [], "files": [ { "description": "", "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Csebfalvi-2002-SBICG-paper.gz", "type": "application/octet-stream", "size": 953100, "path": "Publication:Csebfalvi-2002-SBICG", "url": "https://www.cg.tuwien.ac.at/research/publications/2002/Csebfalvi-2002-SBICG/Csebfalvi-2002-SBICG-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [ "ADAPT" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2002/Csebfalvi-2002-SBICG/", "__class": "Publication" }, { "id": "Neumann-2002-Fea", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Feature-Preserving Volume Filtering", "date": "2002-05", "abstract": "In this paper a feature-preserving volume filtering method is presented. The basic idea is to minimize a three-component global error function penalizing the density and gradient errors and the curvature of the unknown filtered function. The optimization problem leads to a large linear equation system defined by a sparse coefficient matrix. We will show that such an equation system can be efficiently solved in frequency domain using fast Fourier transformation (FFT). For the sake of clarity, first we illustrate our method on a 2D example which is a dedithering problem. Afterwards the 3D extension is discussed in detail since we propose our method mainly for volume filtering. We will show that the 3D version can be efficiently used for elimination of the typical staircase artifacts of direct volume rendering without losing fine details. Unlike local filtering techniques, our novel approach ensures a global smoothing effect. Previous global 3D methods are restricted to binary volumes or segmented iso-surfaces and they are based on area minimization of one single reconstructed surface. In contrast, our method is a general volume-filtering technique, implicitly smoothing all the iso-surfaces at the same time. Although the strength of the presented algorithm is demonstrated on a specific 2D and a specific 3D application, it is considered as a general mathematical tool for processing images and volumes.", "authors_et_al": false, "substitute": null, "main_image": { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 718, "image_height": 717, "name": "Neumann-2002-Fea-image.jpg", "type": "image/jpeg", "size": 96628, "path": "Publication:Neumann-2002-Fea", "url": "https://www.cg.tuwien.ac.at/research/publications/2002/Neumann-2002-Fea/Neumann-2002-Fea-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2002/Neumann-2002-Fea/Neumann-2002-Fea-image:thumb{{size}}.png" }, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 233, 171, 179, 166 ], "booktitle": "Data Visualization 2002", "pages_from": "105", "pages_to": "114", "publisher": "ACM", "research_areas": [], "keywords": [ "antialiasing, noise filtering", "derivative and gradient estimation", "feature-preserving smoothing", "direct volume rendering" ], "weblinks": [], "files": [ { "description": null, "filetitle": "image", "main_file": false, "use_in_gallery": true, "access": "public", "image_width": 718, "image_height": 717, "name": "Neumann-2002-Fea-image.jpg", "type": "image/jpeg", "size": 96628, "path": "Publication:Neumann-2002-Fea", "url": "https://www.cg.tuwien.ac.at/research/publications/2002/Neumann-2002-Fea/Neumann-2002-Fea-image.jpg", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2002/Neumann-2002-Fea/Neumann-2002-Fea-image:thumb{{size}}.png" }, { "description": null, "filetitle": "Paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-2002-Fea-Paper.pdf", "type": "application/pdf", "size": 835899, "path": "Publication:Neumann-2002-Fea", "url": "https://www.cg.tuwien.ac.at/research/publications/2002/Neumann-2002-Fea/Neumann-2002-Fea-Paper.pdf", "thumb_image_sizes": [ 16, 64, 100, 175, 300, 600 ], "thumb_url": "https://www.cg.tuwien.ac.at/research/publications/2002/Neumann-2002-Fea/Neumann-2002-Fea-Paper:thumb{{size}}.png" } ], "projects_workgroups": [ "ADAPT" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2002/Neumann-2002-Fea/", "__class": "Publication" }, { "id": "Csebfalvi-2002-Smo", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Smooth Shape-Based Interpolation using the Conjugate Gradient Method", "date": "2002", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 233, 177, 162, 166 ], "booktitle": "Vision, Modeling, and Visualization 2002", "lecturer": [ 233 ], "publisher": "Akademische Verlagsgesellschaft Aka GmbH, Berlin", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [ "ADAPT" ], "url": "https://www.cg.tuwien.ac.at/research/publications/2002/Csebfalvi-2002-Smo/", "__class": "Publication" }, { "id": "matkovic-2002-visual", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Visual Image Query", "date": "2002", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 235, 177, 477, 450, 190 ], "booktitle": "Smart Graphics 2002", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2002/matkovic-2002-visual/", "__class": "Publication" }, { "id": "Neumann-2000-FPS", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Feature-Preserving Smoothing", "date": "2000-09", "abstract": "The first version of the method presented in this paper\nis derived from\na terrain-modeling problem. The solution of this\nproblem leaded to a\ngeneral technique, which can be used for image\nprocessing purposes like\nimage restoration, noise filtering, and smoothing\npreserving the important\ncontours. The basic idea is the minimization of a\nglobal quadratic penalty\nfunction. This error function contains the quadratic\nglobal curvature of\nthe unknown image and additionally the difference of\nthe data values and\nthe gradient vectors between the original and the\nunknown image. The\ncomponents of the global error are weighted using an\nappropriate weighting\nfunction.\n\nThe gradient vectors are estimated from the original\nnoisy image using\nlinear regression. Under a certain threshold the\ngradient or its weight in\nthe quadratic error function is considered to be zero.\nThe method is\nnon-linear because the operations on the gradients\nand/or the assignment\nof the weighting factors are non-linear.\n\nThe minimization of the penalty function leads to a\nlinear equation system\nwith a large sparse coefficient matrix. It will be\nshown that it can be\nsolved by a special deconvolution if the weighting of\neach pixel is the same.\nThe deconvolution can be performed very efficiently in\nfrequency domain using\nthe well-known FFT algorithm. If the weighting\nfunction depends on pixel\npositions then the general conjugated gradient method\ncan be used in order\nto find the minimum location of the penalty function.\n\nHaving position-dependent weights the flexibility is\nhigher since at the\npositions, where the gradient magnitudes are lower the\nsmoothing effect can\nbe stronger while at the edges smoothing is not\nperformed. The main\ncharacteristic feature of the method can be realized\nwhen it is used for\nimage restoration, where the missing regions have to\nbe reconstructed.\nInstead of interpolation of the pixel values the\ngradient components are\ninterpolated, therefore continuous and non-blurred\ncontours can be obtained.\nThe method calculates densities, which fit best on the\ngradient field. The\nbasic idea can be applied for gradient interpolation\nas well, where the\ncomponent gx and gy of the gradient play the role of\nthe unknown variables.\nAnother special application field is the zooming of\nlow-resolution images\npreserving the sharp contours, which is rather\nimportant in rendering images\non the web or in digital photography. The method can\nbe used for color images\nseparately for three components, for instance using\nCIE Luv coordinates. The\n1D and 3D adaptation are obvious. The 1D version can\nbe used for interpolation\nproblems and sound filtering, while the 3D version is\ncapable for efficient\nprocessing of medical data sets (CT or MRI files),\ngeographical volumes,\narbitrary 3D distributions, or volumes defined by a\nsequence of frames in a\nmovie file.\n\nAmong the special 2D applications one of the most\nimportant ones is the\ncontinuous reconstruction from binary dithered images,\nwhich can be used\nrecursively for image compression. Furthermore, the 2D\nversion is usable for\nadaptive contrast enhancement. In this case, instead\nof the deviation from\nthe original density values, the deviation from a\nconstant value or the\ndeviation from the strongly blurred image is built\ninto the penalty function.\nLast but not least it can be extended to a\nmulti-resolution or hierarchical\nmethod, where the different resolution versions of the\nsame image are\nimproved in a parallel way and derivative filters\ndefined by wide finite\n kernels are used with a ring off weighting.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177 ], "number": "TR-186-2-00-24", "pages_from": "1", "pages_to": "15", "research_areas": [], "keywords": [ "Antialiasing.", "Volume Rendering", "Image Processing" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-2000-FPS-paper.gz", "type": "application/octet-stream", "size": 19145, "path": "Publication:Neumann-2000-FPS", "url": "https://www.cg.tuwien.ac.at/research/publications/2000/Neumann-2000-FPS/Neumann-2000-FPS-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2000/Neumann-2000-FPS/", "__class": "Publication" }, { "id": "Csebfalvi-2000-GELR", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Gradient Estimation in Volume Data using 4D Linear Regression", "date": "2000-02", "abstract": "In this paper a new gradient estimation method is\npresented which is based on linear regression. Previous contextual\nshading techniques try to fit an approximate function to a set of surface\npoints in the neighborhood of a given voxel. Therefore, a system\nof linear equations has to be solved using the computationally\nexpensive Gaussian elimination. In contrast, our method\napproximates the density function itself in a local neighborhood with a 3D\nregression hyperplane. This approach also leads to a system of linear\nequations but we will show that it can be solved with an efficient convolution.\nOur method provides at each voxel location the normal vector and\nthe translation of the regression hyperplane which are considered as a\ngradient and a filtered density value respectively. Therefore, this\ntechnique can be used for surface smoothing and gradient estimation at\nthe same time. ", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 233, 197, 166 ], "number": "TR-186-2-00-03", "pages_from": "1", "pages_to": "11", "research_areas": [], "keywords": [ "Linear Regression.", "Gradient Estimation", "Volume Rendering" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Csebfalvi-2000-GELR-paper.gz", "type": "application/octet-stream", "size": 654844, "path": "Publication:Csebfalvi-2000-GELR", "url": "https://www.cg.tuwien.ac.at/research/publications/2000/Csebfalvi-2000-GELR/Csebfalvi-2000-GELR-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2000/Csebfalvi-2000-GELR/", "__class": "Publication" }, { "id": "Csebfalvi-2000-Gra", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "Gradient Estimation in Volume Data using 4D Linear Regression", "date": "2000", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 166, 177, 197, 233 ], "note": "Eurographics 2000, Interlaken, Switzerland", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2000/Csebfalvi-2000-Gra/", "__class": "Publication" }, { "id": "Neumann-2000-Gra", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "Gradient Estimation in Volume Data using 4D Linear Regression", "date": "2000", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 166, 177, 197, 233 ], "note": "Computer Graphics Forum 19(3), 2000, pp. C-351 - C-357", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/2000/Neumann-2000-Gra/", "__class": "Publication" }, { "id": "Szir-1998-Ref", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "New Simple Reflectance Models for Metals and other Specular Materia\nls", "date": "1998-07", "abstract": "The paper presents new, simple and physically\nplausible, but not physically based reflectance models for\nmetals and other specular materials. The\nmost important member of this family is the modification\nof the Phong model, which can eliminate its\nnon-metallic characteristics. The new model gives back the\nideal mirror in\nthe limit case, is easier to compute than other known models\nand is particularly suitable for importance sampling to\nefficiently generate reflected directions\nin Monte-Carlo ray-tracing algorithms.\nDue to its simplicity, the new\nmodel can become an integral part of commercial CAD systems to\ndescribe the specular part or metallic behavior.\nThe paper also examines the energy balance of the previously\nknown and the newly proposed BRDFs concentrating on the behavior\nat grazing angles, and comes to the conclusion that the Ward and\nthe Cook-Torrance models cannot guarantee energy balance and thus\nare not physically plausible. Finally, the generated images\ndemonstrate how the metallic impression can be provided by the\nnew models.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 232, 206 ], "number": "TR-186-2-98-17", "pages_from": "1", "pages_to": "15", "research_areas": [], "keywords": [ "importance sampling", "albedo function", "BRDF representation", "Reflectance function" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Szir-1998-Ref-paper.gz", "type": "application/octet-stream", "size": 2964360, "path": "Publication:Szir-1998-Ref", "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Szir-1998-Ref/Szir-1998-Ref-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Szir-1998-Ref/", "__class": "Publication" }, { "id": "Szir-1998-Pump", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Analysis and Pumping of the Albedo Function", "date": "1998-07", "abstract": "The paper\nintroduces a method, called the albedo pumping-up, to derive\nnew, physically plausible BRDFs from an existing\none or from any symmetric function.\nThis operation can be applied recursively\nby arbitrary number of times. An important application\nof this operation is the transformation of the Phong and\nBlinn models in order to make them produce\nmetallic effects.\nThe paper also examines the albedo function\nof reflectance models and comes to the conclusion\nthat widely used models violate\nenergy balance at grazing angles.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 232, 206 ], "number": "TR-186-2-98-20", "pages_from": "1", "pages_to": "13", "research_areas": [], "keywords": [ "perceptual based fitting", "metal models", "energy balance", "albedo function", "BRDF representation", "Reflectance function" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Szir-1998-Pump-paper.gz", "type": "application/octet-stream", "size": 530217, "path": "Publication:Szir-1998-Pump", "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Szir-1998-Pump/Szir-1998-Pump-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Szir-1998-Pump/", "__class": "Publication" }, { "id": "Tobler-1998-FFA", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "A new Form Factor Analogy and its Application to\nStochastic Global Illumination Algorithms", "date": "1998-06", "abstract": "A new form factor analogy, that has been derived\nfrom results of integral geometry, is introduced. The new analogy is\nshown to be useful for stochastic evaluation of the local form of the\nrendering equation used in various Monte Carlo methods for calculating\nglobal illumination. It makes it possible to improve importance\nsampling in these methods, thereby speeding up convergence. A new\nclass of bidirectional reflection distribution functions that directly\nbenefits from the analogy and permits exact evaluation and\ncalculation of correctly distributed vectors for Monte Carlo\nintegration is presented.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 216, 177, 207, 190 ], "number": "TR-186-2-98-33", "pages_from": "1", "pages_to": "10", "research_areas": [], "keywords": [ "Sampling", "BRDF", "Global Illumination" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Tobler-1998-FFA-paper.gz", "type": "application/octet-stream", "size": 304660, "path": "Publication:Tobler-1998-FFA", "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Tobler-1998-FFA/Tobler-1998-FFA-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Tobler-1998-FFA/", "__class": "Publication" }, { "id": "Neumann-1998-The", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "The Constant Radiance Term", "date": "1998", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 199, 232 ], "note": "In Machine, Graphics and Vision, No. 7(3), pp.535-549, Polish Academy of Sciences, Warsaw, 1998.", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Neumann-1998-The/", "__class": "Publication" }, { "id": "Tobler-1998-ANe", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "A New Formfactor Analogy", "date": "1998", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 207, 216 ], "note": "In Rendering Techniques´98 (ed. G.Drettakis, N.Max), Springer-Verlag, Wien, July 1998.", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Tobler-1998-ANe/", "__class": "Publication" }, { "id": "Tobler-1998-Anew", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "A new Form Factor Analogy and its Application to Stochastic Global Illumination Algorithms", "date": "1998", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 207, 216 ], "note": "In Rendering Techniques 98, Springer-Verlag, Wien, 1998.", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Tobler-1998-Anew/", "__class": "Publication" }, { "id": "Neumann-1998-Perc", "type_id": "journalpaper", "tu_id": null, "repositum_id": null, "title": "Perception Based Color Image Difference", "date": "1998", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 235, 190 ], "journal": "Computer Graphics Forum", "lecturer": [ 235 ], "note": "Eurographics98, Lissabon, 1998.", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Neumann-1998-Perc/", "__class": "Publication" }, { "id": "Neumann-1998-Per", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "Perception Based Color Image Difference", "date": "1998", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 235 ], "note": "In Computer Graphics Forum 17(3), pp.C/233-C/241, Blackwell, Oxford, Sept. 1998.", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Neumann-1998-Per/", "__class": "Publication" }, { "id": "Neumann-1998-Inc", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "Incident Light Metering in Computer Graphics", "date": "1998", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 232, 235 ], "note": "In Computer Graphics Forum 17(4), pp. 235-247, Blackwell, Oxford, December 1998.", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Neumann-1998-Inc/", "__class": "Publication" }, { "id": "Neumann-1998-Aut", "type_id": "misc", "tu_id": null, "repositum_id": null, "title": "Automatic Exposure in Computer Graphics based on the Minimum Information Loss Principle", "date": "1998", "abstract": null, "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 235 ], "note": "In proceedings of CGI98, Hannover, Germany, 1998.", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1998/Neumann-1998-Aut/", "__class": "Publication" }, { "id": "Neumann-1997-PBCID", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Perception Based Color Image Difference", "date": "1997-12", "abstract": "A good image metric is often needed in digital image\nsynthesis. It can be used to check the convergence behavior in\nprogressive methods, to compare images rendered using various\nrendering methods etc. Since images are rendered to be observed by\nhumans, an image metric should correspond to human perception as\nwell. We propose here a new algorithm which operates in the original\nimage space. There is no need for Fourier or wavelet\ntransforms. Furthermore, the new metric is view distance\ndependent. The new method uses the contrast sensitivity\nfunction\\cite{[MANN74]}. The main idea is to place a number of various\nrectangles in images, and to compute the CIE LUV average color\ndifference between corresponding rectangles. Errors are then weighted\naccording to the rectangle size and the contrast sensitivity\nfunction.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 235, 190 ], "number": "TR-186-2-97-21", "pages_from": "", "pages_to": "", "research_areas": [], "keywords": [ "image comparisson", "perception based rendering" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-1997-PBCID-paper.gz", "type": "application/octet-stream", "size": 1122980, "path": "Publication:Neumann-1997-PBCID", "url": "https://www.cg.tuwien.ac.at/research/publications/1997/Neumann-1997-PBCID/Neumann-1997-PBCID-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1997/Neumann-1997-PBCID/", "__class": "Publication" }, { "id": "Kresimir-1997-STMT", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "A Survey of Tone Mapping Techniques", "date": "1997-04", "abstract": "This paper gives a survey of tone mapping techniques\nusid with global illumination models. Linear and non-linear methods\nare compared, and drawbacks and strengths of all methods are given\naccording to the authors' opinions. The tone mapping is an important\nstep in the rendering process, and this survey can help potentional\nusers to choose the right mapping technique for a particular\npurpose.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 235, 177, 190 ], "number": "TR-186-2-97-12", "pages_from": "1", "pages_to": "6", "research_areas": [], "keywords": [ "color mapping", "global illumination", "tone mapping" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Kresimir-1997-STMT-paper.gz", "type": "application/octet-stream", "size": 3572949, "path": "Publication:Kresimir-1997-STMT", "url": "https://www.cg.tuwien.ac.at/research/publications/1997/Kresimir-1997-STMT/Kresimir-1997-STMT-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1997/Kresimir-1997-STMT/", "__class": "Publication" }, { "id": "Kresimir-1997-ILMCG", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Incident Light Metering in Computer Graphics", "date": "1997-04", "abstract": "Every rendering process consists of two steps. The\nfirst is the computing of luminance values by methods like ray tracing\nor radiosity, and the second step is the mapping of the computed\nvalues to values appropriate for displaying. In the last years, as\nalternative to simple linear scaling which maps the average value to\nthe medium lumninance, some new ways of mapping were introduced. These\nnew methods are based on photography analogies and on human vision\nmodels. All existing methods follow, implicitly or explicitly, the\nreflected light metering principle. The method introduced in this\npaper is the first that follows the incident light metering used in\nprofessional photography and in the movie industry. Actually the\nirradiances are measured using a set of diffusors, which are placed\nautomatically in the scene, and a linear scale factor based on these\nmeasurements is used to map the computed radiances to the display\ndevice. The diffusors act as half space integrators, they collect the\nlight energy from all half space directions. The light comes from the\nprimary light sources, or it is the result of various\ninterreflections. The newly introduced method reproduces original\ncolors faithfully even for scenes with very low or very high average\nreflectivity.Every rendering process consists of two steps. The first\nis the computing of luminance values by methods like ray tracing or\nradiosity, and the second step is the mapping of the computed values\nto values appropriate for displaying. In the last years, as\nalternative to simple linear scaling which maps the average value to\nthe medium lumninance, some new ways of mapping were introduced. These\nnew methods are based on photography analogies and on human vision\nmodels. All existing methods follow, implicitly or explicitly, the\nreflected light metering principle. The method introduced in this\npaper is the first that follows the incident light metering used in\nprofessional photography and in the movie industry. Actually the\nirradiances are measured using a set of diffusors, which are placed\nautomatically in the scene, and a linear scale factor based on these\nmeasurements is used to map the computed radiances to the display\ndevice. The diffusors act as half space integrators, they collect the\nlight energy from all half space directions. The light comes from the\nprimary light sources, or it is the result of various\ninterreflections. The newly introduced method reproduces original\ncolors faithfully even for scenes with very low or very high average\nreflectivity.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 235, 177, 232, 190 ], "number": "TR-186-2-97-11", "pages_from": "1", "pages_to": "9", "research_areas": [], "keywords": [ "color mapping", "global illumination", "tone mapping" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Kresimir-1997-ILMCG-paper.gz", "type": "application/octet-stream", "size": 6155740, "path": "Publication:Kresimir-1997-ILMCG", "url": "https://www.cg.tuwien.ac.at/research/publications/1997/Kresimir-1997-ILMCG/Kresimir-1997-ILMCG-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1997/Kresimir-1997-ILMCG/", "__class": "Publication" }, { "id": "Neumann-1996-NCB", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "A New Class of BRDF Models with Fast Importance Sampling", "date": "1996-12", "abstract": "We introduce a physically plausible mathematical model\nfor a large class of BRDFs. The new model can be defined\nin a user-friendly way and it is as simple as the\nwell-known Phong model, without any of its disadvantages.\nIt gives a good visual approximation of a lot of practical\nmaterials: metals, plastics, ceramics, retro-reflective\npaints, anisotropic materials, etc. The new model includes\nthe ideal diffuse model and ideal mirror as well, reflecting\nall of the incoming energy. Because of its illustrative\nproperties it can be used easily in most commercial\nsoftware and because of its low computational cost it is\n practical for VR.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 232 ], "number": "TR-186-2-96-24", "pages_from": "1", "pages_to": "25", "research_areas": [], "keywords": [ "rendering", "reflection models", "anisotropy", "retro-reflective models", "BRDF", "albedo", "Monte Carlo", "imporance sampling" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-1996-NCB-paper.gz", "type": "application/octet-stream", "size": 176434, "path": "Publication:Neumann-1996-NCB", "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Neumann-1996-NCB/Neumann-1996-NCB-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Neumann-1996-NCB/", "__class": "Publication" }, { "id": "Neumann-1996-CRS", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "The Constant Radiance Term", "date": "1996-04", "abstract": "The proposed method accelerates the computation of\nmultiple interreflections in non-diffuse environments or\nthe solution of the rendering equation. The method is\nsuited for closed environments. It is a generalization of\nthe 'constant radiosity step' introduced for diffuse\nenvironments and does not require geometrical or\nvisibility information, nor the calculation of form\nfactors. A constant radiance is extracted from the\nsolution in every surface point and every direction. We\nchoose this constant value so that the average self\nemitted power of the residuum problem is zero. The self\nemitting term of the residuum problem can either be\npositive or negative. Direction dependency is determined\nby the albedo function of the characteristic BRDF of the\nsurface. This function can easily be pretabulated and it\nis used frequently throughout this paper. The residuum\nproblem can be solved faster or with reduced variance by\nall known non-diffuse methods: different versions of\ndistribution ray tracing, proper methods of radiosity,\nand hybrid solutions. The acceleration achieved by the\n proposed method can be significant for bright environments.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177 ], "number": "TR-186-2-96-13", "pages_from": "1", "pages_to": "9", "research_areas": [], "keywords": [ "radiosity", "constant radiance step" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-1996-CRS-paper.gz", "type": "application/octet-stream", "size": 94954, "path": "Publication:Neumann-1996-CRS", "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Neumann-1996-CRS/Neumann-1996-CRS-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Neumann-1996-CRS/", "__class": "Publication" }, { "id": "Matkovic-1996-ICM", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Interactive Calibration of the Mapping of Global\n\t\t Illumination Values to Display Devices", "date": "1996-03", "abstract": "A different approach to mapping the global illumination\nvalues to display devices is introduced. The final\nimage is displayed with appropriate atmosphere,\nthereby the luminances in absolute units are not\nneeded, what makes the method suitable for a wide\nrange of rendering software. The method is inspired\nby the photographersÕ approach. The results strongly\ndepend on user setting, thus making the method\n\t\t completely subjective.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 235, 177 ], "number": "TR-186-2-96-07", "pages_from": "", "pages_to": "", "research_areas": [], "keywords": [ "color mapping" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Matkovic-1996-ICM-paper.gz", "type": "application/octet-stream", "size": 596945, "path": "Publication:Matkovic-1996-ICM", "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Matkovic-1996-ICM/Matkovic-1996-ICM-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Matkovic-1996-ICM/", "__class": "Publication" }, { "id": "Neumann-1996-AEC", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Automatic Exposure in Computer Graphics based on the\n\t\t Minimum Information Loss Principle", "date": "1996-03", "abstract": "The available contrast of common display devices is\nmuch lower than image data often demand. Usually a\nvariant of an average of the field of view is used\nto normalize the image. In this paper an alternative\napproach will be taken to define the mapping of\nrendered values to the displayable intensity range.\nThe luminance range is chosen such that a minimum\namount of information is lost, thereby preserving\nthe contrast ratio of all correctly displayed\nparts. The loss of information can be regulated by\ndifferent error functions. The introduced method\n\t\t can be applied on the color and gray scale images", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 235, 190 ], "number": "TR-186-2-96-08", "pages_from": "", "pages_to": "", "research_areas": [], "keywords": [ "color mapping" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-1996-AEC-paper.gz", "type": "application/octet-stream", "size": 680366, "path": "Publication:Neumann-1996-AEC", "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Neumann-1996-AEC/Neumann-1996-AEC-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1996/Neumann-1996-AEC/", "__class": "Publication" }, { "id": "neumann-1995-anew", "type_id": "inbook", "tu_id": null, "repositum_id": null, "title": "A New Stochastic Radiosity Method for Highly Complex Scenes", "date": "1995-08", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 245, 413, 190 ], "booktitle": "In Photorealistic Rendering Techniques", "editor": "G. Sakas, P. Shirley, S. Müller", "isbn": "3540584757", "pages_from": "201", "pages_to": "213", "publisher": "Springer", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1995/neumann-1995-anew/", "__class": "Publication" }, { "id": "neumann-1995-cons", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "The Constant Radiosity Step", "date": "1995-07", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 216, 439 ], "booktitle": "Rendering Techniques", "editor": "P. Hanrahan, W. Purgathofer", "location": "Wien, Austria", "note": "TALK: R. Tobler 13.5.1995", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1995/neumann-1995-cons/", "__class": "Publication" }, { "id": "Neumann-1995-SRM", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "The Stochastic Ray Method for Radiosity", "date": "1995-01", "abstract": "This paper solves the system of radiosity\nequations with a numerical approach rather than\nwith a physical interpretation as most current\nalgorithms do. Due to the high complexity of the\nproblem for highly complex scenes, a stochastic\nvariation of Jacobi iteration is developed which\nconverges stochastically to the correct solution.\nThe new method, called Stochastic Ray Method, is a\nsignificant improvement of Stochastic Radiosity. A\nlarge number of independent rays is chosen\nstochastically by importance sampling of the\npatches according to their power after the previous\niteration step. They all carry an equal amount of\npower into random directions, thereby representing\ntogether the total energy interreflection of the\nentire environment in a stochastic manner.\nAssuming a correctly distributed initial solution,\nwhich can be reached easily, the iteration\nprocess converges quickly and reduces the error\nin the result faster than other stochastic\nradiosity approaches. The new algorithm can\neasily be extended to treat various phenomena which\nare normally rather costly to incorporate in\nradiosity environments: specular reflection and\nspecular transmittance, non-diffuse emission and\n point light sources.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 216, 232, 439, 245, 440 ], "number": "TR-186-2-95-3", "pages_from": "1", "pages_to": "8", "research_areas": [], "keywords": [ "rendering", "radiosity", "stochastic", "raytracing" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Neumann-1995-SRM-paper.gz", "type": "application/octet-stream", "size": 55968, "path": "Publication:Neumann-1995-SRM", "url": "https://www.cg.tuwien.ac.at/research/publications/1995/Neumann-1995-SRM/Neumann-1995-SRM-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1995/Neumann-1995-SRM/", "__class": "Publication" }, { "id": "neumann-1995-the", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "The Stochastic Ray Method for Radiosity", "date": "1995", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 216, 232, 439, 245, 440 ], "booktitle": "Rendering Techniques", "editor": "P. Hanrahan, W. Purgathofer", "location": "Wien, Austria", "note": "TALK: M. Feda 13.5.1995", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1995/neumann-1995-the/", "__class": "Publication" }, { "id": "Neumann-1994-SRM", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "The Stochastic Ray Method for Radiosity", "date": "1994-11", "abstract": "THIS TECHNICAL REPORT IS OUTDATED AND HAS BEEN SUPERSEDED BY TR-186-2-95-3.\nThis paper presents an efficient radiosity\nalgorithm for highly complex scenes. The new\niteration method, which is based on the Stochastic\nShooting Method, uses ray tracing to implicitly\ncalculate form factors. The variance in the solution\nis reduced by using a self-correcting, stochastically\nconverging iteration formula. The new algorithm can\nbe easily extended to simulate various phenomena\nnormally not found in radiosity environments:\ntransparency, specular reflection and point\n light-sources.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 190, 216, 232, 439, 245, 440 ], "number": "TR-186-2-94-17", "pages_from": "1", "pages_to": "13", "research_areas": [], "keywords": [ "" ], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1994/Neumann-1994-SRM/", "__class": "Publication" }, { "id": "Feda-1994-FPZ", "type_id": "techreport", "tu_id": null, "repositum_id": null, "title": "Fast Perspective Z-Buffer with Inverse Depths", "date": "1994-11", "abstract": "This paper presents a way to hold the depth\ninformation in Z-buffers, that allows fast\nincremental computation of Z-buffer depth values.\nThe main idea is to store the inverse depth with\neach pixel value. The incremental depth computation\ncan then be done with a single addition per pixel\n in a scanline.", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 245, 216, 177 ], "number": "TR-186-2-94-16", "pages_from": "1", "pages_to": "3", "research_areas": [], "keywords": [ "z-buffer", "optimization", "rendering" ], "weblinks": [], "files": [ { "description": null, "filetitle": "paper", "main_file": true, "use_in_gallery": false, "access": "public", "name": "Feda-1994-FPZ-paper.gz", "type": "application/octet-stream", "size": 19872, "path": "Publication:Feda-1994-FPZ", "url": "https://www.cg.tuwien.ac.at/research/publications/1994/Feda-1994-FPZ/Feda-1994-FPZ-paper.gz", "thumb_image_sizes": [] } ], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1994/Feda-1994-FPZ/", "__class": "Publication" }, { "id": "purgathofer-1994-rad", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "Radiosity for very Complex Scenes", "date": "1994-06", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 190, 177, 245, 413 ], "booktitle": "Proceedings of International Conference on Computer Graphics ICCG", "location": "Comenius University of Bratislava, Slovakia", "note": "TALK: W. Purgathofer 7.6.1994", "organization": "International Conference on Computer Graphics ICCG", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1994/purgathofer-1994-rad/", "__class": "Publication" }, { "id": "neumann-1994-new", "type_id": "inproceedings", "tu_id": null, "repositum_id": null, "title": "A New Stochastic Radiosity Method for Highly Complex Scenes", "date": "1994-06", "abstract": "", "authors_et_al": false, "substitute": null, "main_image": null, "sync_repositum_override": null, "repositum_presentation_id": null, "authors": [ 177, 245, 413, 190 ], "booktitle": "Proceedings of Fifth Eurographics Workshop on Rendering", "note": "TALK: W. Purgathofer 14.6.1994", "organization": "Fifth Eurographics Workshop on Rendering", "research_areas": [], "keywords": [], "weblinks": [], "files": [], "projects_workgroups": [], "url": "https://www.cg.tuwien.ac.at/research/publications/1994/neumann-1994-new/", "__class": "Publication" } ]