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Author (down) Jordi Vitria; J. Llacer edit  doi
openurl 
  Title Reconstructing 3D light microscopic images using the EM algorithm Type Journal
  Year 1996 Publication Pattern Recognition Letters Abbreviated Journal  
  Volume 17 Issue 14 Pages 1491–1498  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ ViL1996 Serial 74  
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Author (down) Jordi Vitria; J. Llacer edit  openurl
  Title Recovering brightness and depth from focus using the Expectation-Maximization Algorithm. Type Miscellaneous
  Year 1995 Publication VI National Simposium on Pattern Recognition and image Analysis Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract  
  Address Cordoba  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ ViL1995 Serial 134  
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Author (down) Jordi Vitria; J. Llacer edit  openurl
  Title Recovering Depth from Focus Using Iterative image Estimation Techniques. Type Miscellaneous
  Year 1993 Publication Tech.Report BL–35158, Lawrence Berkeley Laboratory. Abbreviated Journal  
  Volume Issue Pages  
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  Abstract  
  Address University of California; Berkeley; USA;  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ ViL1993 Serial 142  
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Author (down) Jordi Vitria; C. Gratin; D. Seron; F. Moreso edit  openurl
  Title Morphological image analysis for quantification of renal damage Type Report
  Year 1995 Publication CVC Technical Report #02 Abbreviated Journal  
  Volume Issue Pages  
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  Abstract  
  Address CVC (UAB)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ VGS1995 Serial 117  
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Author (down) Jordi Vitria edit  openurl
  Title Disseny de sistemes (intel.ligents) de visio. Type Miscellaneous
  Year 1996 Publication Abbreviated Journal  
  Volume Issue Pages  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ Vit1996a Serial 88  
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Author (down) Jordi Vitria edit  openurl
  Title Introduccio a la Morfologia Matematica Type Report
  Year 1996 Publication CVC Technical Report #06 Abbreviated Journal  
  Volume Issue Pages  
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  Abstract  
  Address CVC (UAB)  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes OR;MV Approved no  
  Call Number BCNPCL @ bcnpcl @ Vit1996b Serial 90  
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Author (down) Jordi Roca; Maria Vanrell; C. Alejandro Parraga edit  url
isbn  openurl
  Title What is constant in colour constancy? Type Conference Article
  Year 2012 Publication 6th European Conference on Colour in Graphics, Imaging and Vision Abbreviated Journal  
  Volume Issue Pages 337-343  
  Keywords  
  Abstract Color constancy refers to the ability of the human visual system to stabilize
the color appearance of surfaces under an illuminant change. In this work we studied how the interrelations among nine colors are perceived under illuminant changes, particularly whether they remain stable across 10 different conditions (5 illuminants and 2 backgrounds). To do so we have used a paradigm that measures several colors under an immersive state of adaptation. From our measures we defined a perceptual structure descriptor that is up to 87% stable over all conditions, suggesting that color category features could be used to predict color constancy. This is in agreement with previous results on the stability of border categories [1,2] and with computational color constancy
algorithms [3] for estimating the scene illuminant.
 
  Address  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN 9781622767014 Medium  
  Area Expedition Conference CGIV  
  Notes CIC Approved no  
  Call Number RVP2012 Serial 2189  
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Author (down) Jordi Roca; C. Alejandro Parraga; Maria Vanrell edit  url
openurl 
  Title Categorical Focal Colours are Structurally Invariant Under Illuminant Changes Type Conference Article
  Year 2011 Publication European Conference on Visual Perception Abbreviated Journal  
  Volume Issue Pages 196  
  Keywords  
  Abstract The visual system perceives the colour of surfaces approximately constant under changes of illumination. In this work, we investigate how stable is the perception of categorical \“focal\” colours and their interrelations with varying illuminants and simple chromatic backgrounds. It has been proposed that best examples of colour categories across languages cluster in small regions of the colour space and are restricted to a set of 11 basic terms (Kay and Regier, 2003 Proceedings of the National Academy of Sciences of the USA 100 9085\–9089). Following this, we developed a psychophysical paradigm that exploits the ability of subjects to reliably reproduce the most representative examples of each category, adjusting multiple test patches embedded in a coloured Mondrian. The experiment was run on a CRT monitor (inside a dark room) under various simulated illuminants. We modelled the recorded data for each subject and adapted state as a 3D interconnected structure (graph) in Lab space. The graph nodes were the subject\’s focal colours at each adaptation state. The model allowed us to get a better distance measure between focal structures under different illuminants. We found that perceptual focal structures tend to be preserved better than the structures of the physical \“ideal\” colours under illuminant changes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Perception 40 Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference ECVP  
  Notes CIC Approved no  
  Call Number Admin @ si @ RPV2011 Serial 1867  
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Author (down) Jordi Roca; C. Alejandro Parraga; Maria Vanrell edit   pdf
doi  openurl
  Title Chromatic settings and the structural color constancy index Type Journal Article
  Year 2013 Publication Journal of Vision Abbreviated Journal JV  
  Volume 13 Issue 4-3 Pages 1-26  
  Keywords  
  Abstract Color constancy is usually measured by achromatic setting, asymmetric matching, or color naming paradigms, whose results are interpreted in terms of indexes and models that arguably do not capture the full complexity of the phenomenon. Here we propose a new paradigm, chromatic setting, which allows a more comprehensive characterization of color constancy through the measurement of multiple points in color space under immersive adaptation. We demonstrated its feasibility by assessing the consistency of subjects' responses over time. The paradigm was applied to two-dimensional (2-D) Mondrian stimuli under three different illuminants, and the results were used to fit a set of linear color constancy models. The use of multiple colors improved the precision of more complex linear models compared to the popular diagonal model computed from gray. Our results show that a diagonal plus translation matrix that models mechanisms other than cone gain might be best suited to explain the phenomenon. Additionally, we calculated a number of color constancy indices for several points in color space, and our results suggest that interrelations among colors are not as uniform as previously believed. To account for this variability, we developed a new structural color constancy index that takes into account the magnitude and orientation of the chromatic shift in addition to the interrelations among colors and memory effects.  
  Address  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes CIC; 600.052; 600.051; 605.203 Approved no  
  Call Number Admin @ si @ RPV2013 Serial 2288  
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Author (down) Jordi Roca; C. Alejandro Parraga; Maria Vanrell edit   pdf
url  openurl
  Title Predicting categorical colour perception in successive colour constancy Type Abstract
  Year 2012 Publication Perception Abbreviated Journal PER  
  Volume 41 Issue Pages 138  
  Keywords  
  Abstract Colour constancy is a perceptual mechanism that seeks to keep the colour of objects relatively stable under an illumination shift. Experiments haveshown that its effects depend on the number of colours present in the scene. We
studied categorical colour changes under different adaptation states, in particular, whether the colour categories seen under a chromatically neutral illuminant are the same after a shift in the chromaticity of the illumination. To do this, we developed the chromatic setting paradigm (2011 Journal of Vision11 349), which is as an extension of achromatic setting to colour categories. The paradigm exploits the ability of subjects to reliably reproduce the most representative examples of each category, adjusting multiple test patches embedded in a coloured Mondrian. Our experiments were run on a CRT monitor (inside a dark room) under various simulated illuminants and restricting the number of colours of the Mondrian background to three, thus weakening the adaptation effect. Our results show a change in the colour categories present before (under neutral illumination) and after adaptation (under coloured illuminants) with a tendency for adapted colours to be less saturated than before adaptation. This behaviour was predicted by a simple
affine matrix model, adjusted to the chromatic setting results.
 
  Address  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0301-0066 ISBN Medium  
  Area Expedition Conference  
  Notes CIC Approved no  
  Call Number Admin @ si @ RPV2012 Serial 2188  
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Author (down) Jordi Roca; A.Owen; G.Jordan; Y.Ling; C. Alejandro Parraga; A.Hurlbert edit  url
doi  openurl
  Title Inter-individual Variations in Color Naming and the Structure of 3D Color Space Type Abstract
  Year 2011 Publication Journal of Vision Abbreviated Journal VSS  
  Volume 12 Issue 2 Pages 166  
  Keywords  
  Abstract 36.307
Many everyday behavioural uses of color vision depend on color naming ability, which is neither measured nor predicted by most standardized tests of color vision, for either normal or anomalous color vision. Here we demonstrate a new method to quantify color naming ability by deriving a compact computational description of individual 3D color spaces. Methods: Individual observers underwent standardized color vision diagnostic tests (including anomaloscope testing) and a series of custom-made color naming tasks using 500 distinct color samples, either CRT stimuli (“light”-based) or Munsell chips (“surface”-based), with both forced- and free-choice color naming paradigms. For each subject, we defined his/her color solid as the set of 3D convex hulls computed for each basic color category from the relevant collection of categorised points in perceptually uniform CIELAB space. From the parameters of the convex hulls, we derived several indices to characterise the 3D structure of the color solid and its inter-individual variations. Using a reference group of 25 normal trichromats (NT), we defined the degree of normality for the shape, location and overlap of each color region, and the extent of “light”-“surface” agreement. Results: Certain features of color perception emerge from analysis of the average NT color solid, e.g.: (1) the white category is slightly shifted towards blue; and (2) the variability in category border location across NT subjects is asymmetric across color space, with least variability in the blue/green region. Comparisons between individual and average NT indices reveal specific naming “deficits”, e.g.: (1) Category volumes for white, green, brown and grey are expanded for anomalous trichromats and dichromats; and (2) the focal structure of color space is disrupted more in protanopia than other forms of anomalous color vision. The indices both capture the structure of subjective color spaces and allow us to quantify inter-individual differences in color naming ability.
 
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1534-7362 ISBN Medium  
  Area Expedition Conference  
  Notes CIC Approved no  
  Call Number Admin @ si @ ROJ2011 Serial 1758  
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Author (down) Jordi Roca edit  openurl
  Title Constancy and inconstancy in categorical colour perception Type Book Whole
  Year 2012 Publication PhD Thesis, Universitat Autonoma de Barcelona-CVC Abbreviated Journal  
  Volume Issue Pages  
  Keywords  
  Abstract To recognise objects is perhaps the most important task an autonomous system, either biological or artificial needs to perform. In the context of human vision, this is partly achieved by recognizing the colour of surfaces despite changes in the wavelength distribution of the illumination, a property called colour constancy. Correct surface colour recognition may be adequately accomplished by colour category matching without the need to match colours precisely, therefore categorical colour constancy is likely to play an important role for object identification to be successful. The main aim of this work is to study the relationship between colour constancy and categorical colour perception. Previous studies of colour constancy have shown the influence of factors such the spatio-chromatic properties of the background, individual observer's performance, semantics, etc. However there is very little systematic study of these influences. To this end, we developed a new approach to colour constancy which includes both individual observers' categorical perception, the categorical structure of the background, and their interrelations resulting in a more comprehensive characterization of the phenomenon. In our study, we first developed a new method to analyse the categorical structure of 3D colour space, which allowed us to characterize individual categorical colour perception as well as quantify inter-individual variations in terms of shape and centroid location of 3D categorical regions. Second, we developed a new colour constancy paradigm, termed chromatic setting, which allows measuring the precise location of nine categorically-relevant points in colour space under immersive illumination. Additionally, we derived from these measurements a new colour constancy index which takes into account the magnitude and orientation of the chromatic shift, memory effects and the interrelations among colours and a model of colour naming tuned to each observer/adaptation state. Our results lead to the following conclusions: (1) There exists large inter-individual variations in the categorical structure of colour space, and thus colour naming ability varies significantly but this is not well predicted by low-level chromatic discrimination ability; (2) Analysis of the average colour naming space suggested the need for an additional three basic colour terms (turquoise, lilac and lime) for optimal colour communication; (3) Chromatic setting improved the precision of more complex linear colour constancy models and suggested that mechanisms other than cone gain might be best suited to explain colour constancy; (4) The categorical structure of colour space is broadly stable under illuminant changes for categorically balanced backgrounds; (5) Categorical inconstancy exists for categorically unbalanced backgrounds thus indicating that categorical information perceived in the initial stages of adaptation may constrain further categorical perception.  
  Address  
  Corporate Author Thesis Ph.D. thesis  
  Publisher Place of Publication Editor Maria Vanrell;C. Alejandro Parraga  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
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  Notes CIC Approved no  
  Call Number Admin @ si @ Roc2012 Serial 2893  
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Author (down) Jordi Gonzalez; X. Varona; Xavier Roca; Juan J. Villanueva edit  openurl
  Title Human Activity Learning and Recognition from Appearance. Type Miscellaneous
  Year 2001 Publication World Multiconference on Systemics, Cybernetics and Informatics SCI 2001, XIII:463–466 Abbreviated Journal  
  Volume Issue Pages  
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  Abstract  
  Address USA  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes ISE Approved no  
  Call Number ISE @ ise @ GVR2001 Serial 108  
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Author (down) Jordi Gonzalez; X. Varona; Xavier Roca; Juan J. Villanueva edit  openurl
  Title Automatic Keyframing of Human Actions for Computer Animation Type Miscellaneous
  Year 2003 Publication Abbreviated Journal  
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  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes ISE Approved no  
  Call Number ISE @ ise @ GVR2003a Serial 359  
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Author (down) Jordi Gonzalez; X. Varona; Xavier Roca; Juan J. Villanueva edit  openurl
  Title A Human Action Comparison Framework for Motion Understanding Type Miscellaneous
  Year 2003 Publication Abbreviated Journal  
  Volume Issue Pages  
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  Abstract  
  Address Palma de Mallorca, Spain  
  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes ISE Approved no  
  Call Number ISE @ ise @ GVR2003e Serial 361  
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