• An Adaptive Combination of Dark and Bright Channel Priors for Single Image Dehazing 

      Whannou De Dravo, Vincent Jacob; El Khoury, Jessica; Thomas, Jean-Baptiste; Mansouri, Alamin; Hardeberg, Jon Yngve (Journal article; Peer reviewed, 2017)
      Dehazing methods based on prior assumptions derived from statistical image properties fail when these properties do not hold. This is most likely to happen when the scene contains large bright areas, such as snow and sky, ...
    • An Evaluation Framework for Spectral Filter Array Cameras to Optimize Skin Diagnosis 

      Bauer, Jacob Renzo; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve; Verdaasdonk, Rudolf M. (Journal article; Peer reviewed, 2019)
      Comparing and selecting an adequate spectral filter array (SFA) camera is application-specific and usually requires extensive prior measurements. An evaluation framework for SFA cameras is proposed and three cameras are ...
    • Analytical Survey of Highlight Detection in Color and Spectral Images 

      Khan, Haris Ahmad; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve (Chapter, 2017)
      Detection of highlights is a prominent issue in computer vision, graphics and image processing. Applications which require object properties measurement or rendering are affected by specular reflection since the models ...
    • Behavioral Investigation of Visual Appearance Assessment 

      Gigilashvili, Davit; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve; Pedersen, Marius (Journal article; Peer reviewed, 2018)
      The way people judge, assess and express appearance they perceive can dramatically vary from person to person. The objective of this study is to identify the research hypotheses and outline directions for the future work ...
    • Color and sharpness assessment of single image dehazing 

      El Khoury, Jessica; Le Moan, Steven; Thomas, Jean-Baptiste; Mansouri, Alamin (Journal article; Peer reviewed, 2017)
      Image dehazing is the process of enhancing a color image of a natural scene that contains an undesirable veil of fog for visualization or as a pre-processing step for computer vision systems. In this work, we investigate ...
    • Demosaicing of periodic and random colour filter arrays by linear anisotropic diffusion 

      Thomas, Jean-Baptiste; Farup, Ivar (Journal article; Peer reviewed, 2018)
      The authors develop several versions of the diffusion equation to demosaic color filter arrays of any kind. In particular, they compare isotropic versus anisotropic and linear versus non-linear formulations. Using these ...
    • Energy balance in Spectral Filter Array camera design 

      Lapray, Pierre-Jean; Thomas, Jean-Baptiste; Gouton, Pierre; Ruichek, Yassine (Journal article; Peer reviewed, 2017)
      Background Multispectral imaging permits to capture more spectral information on object surface properties than color imaging. This is useful for machine vision applications. Transmittance spectral filter arrays combined ...
    • Filter array based spectral imaging : Demosaicking and design considerations 

      Wang, Xingbo (Doctoral thesis at NTNU;2016;, Doctoral thesis, 2016)
      Spectral imaging apparatus in current use are often cumbersome, costly and slow in operation, which becomes a major obstacle to extensive use of spectral imaging in several application areas. In recent years, the technical ...
    • High Dynamic Range Spectral Imaging Pipeline For Multispectral Filter Array Cameras 

      Lapray, Pierre-Jean; Thomas, Jean-Baptiste; Gouton, Pierre (Journal article; Peer reviewed, 2017)
      Spectral filter arrays imaging exhibits a strong similarity with color filter arrays. This permits us to embed this technology in practical vision systems with little adaptation of the existing solutions. In this communication, ...
    • HyTexiLa: high resolution visible and near infrared hyperspectral texture images 

      Khan, Haris Ahmad; Mihoubi, Soufiane; Mathon, Benjamin; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve (Journal article; Peer reviewed, 2018)
      We present a dataset of close range hyperspectral images of materials that span the visible and near infrared spectrums: HyTexiLa (Hyperspectral Texture images acquired in Laboratory). The data is intended to provide high ...
    • Illuminant estimation in multispectral imaging 

      Khan, Haris Ahmad; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve; Laligant, Olivier (Journal article; Peer reviewed, 2017)
      With the advancement in sensor technology, the use of multispectral imaging is gaining wide popularity for computer vision applications. Multispectral imaging is used to achieve better discrimination between the radiance ...
    • Impact of Shape on Apparent Translucency Differences 

      Gigilashvili, Davit; Urban, Philipp; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve; Pedersen, Marius (Journal article; Peer reviewed, 2019)
      Translucency is one of the major appearance attributes. Apparent translucency is impacted by various factors including object shape and geometry. Despite general proposals that object shape and geometry have a significant ...
    • An inverse display color characterization model based on an optimized geometrical structure 

      Thomas, Jean-Baptiste; Colantoni, Philippe; Hardeberg, Jon Yngve; Foucherot, Irene; Gouton, Pierre (Proceedings of SPIE;6807, Journal article; Peer reviewed, 2008)
      We have defined an inverse model for colorimetric characterization of additive displays. It is based on an optimized three-dimensional tetrahedral structure. In order to minimize the number of measurements, the structure ...
    • Material Appearance: Ordering and Clustering 

      Gigilashvili, Davit; Thomas, Jean-Baptiste; Pedersen, Marius; Hardeberg, Jon Yngve (Journal article; Peer reviewed, 2019)
      Appearance is a complex psychovisual phenomenon impacted by various objective and subjective factors that are not yet fully understood. In this work we use real objects and unconstrained conditions to study appearance ...
    • Multispectral camera as spatio-spectrophotometer under uncontrolled illumination 

      Khan, Haris Ahmad; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve; Laligant, Olivier (Journal article; Peer reviewed, 2019)
      Multispectral constancy enables the illuminant invariant representation of multi-spectral data. This article proposes an experimental investigation of multispectral constancy through the use of multispectral camera as a ...
    • Multispectral Constancy Based on Spectral Adaptation Transform 

      Khan, Haris Ahmad; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve (Chapter, 2017)
      The spectral reflectance of an object surface provides valuable information about its characteristics. Reflectance reconstruction from multispectral images is based on certain assumptions. One of these assumptions is that ...
    • Multispectral filter arrays: Recent advances and practical implementation 

      Lapray, Pierre-Jean; Wang, Xingbo; Thomas, Jean-Baptiste; Gouton, Pierre (Journal article; Peer reviewed, 2014)
      Thanks to some technical progress in interferencefilter design based on different technologies, we can finally successfully implement the concept of multispectral filter array-based sensors. This article provides the ...
    • Multispectral imaging: narrow or wide band filters? 

      Wang, Xingbo; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve; Gouton, Pierre (Journal article; Peer reviewed, 2014)
      In every aspect, spectral characteristics of filters play an important role in an image acquisition system. For a colorimetric system, traditionally, it is believed that narrow-band filters give rise to higher accuracy ...
    • N-LMMSE Demosaicing for Spectral Filter Arrays 

      Amba, Prakhar; Thomas, Jean-Baptiste; Alleysson, David (Journal article; Peer reviewed, 2017)
      Spectral filter array (SFA) technology requires development on demosaicing. The authors extend the linear minimum mean square error with neighborhood method to the spectral dimension. They demonstrate that the method is ...
    • On the Acquisition and Reproduction of Material Appearance 

      Sole, Aditya Suneel; Gigilashvili, Davit; Midtfjord, Helene B.; Guarnera, Dar'ya; Guarnera, Giuseppe Claudio; Thomas, Jean-Baptiste; Hardeberg, Jon Yngve (Chapter, 2019)
      Currently, new technologies (e.g. 2.5D and 3D printing processes) progress at a fast pace in their capacity to (re)produce an ever-broader range of visual aspects. At the same time, a huge research effort is needed to ...