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Reflectance estimation from urban terrestrial images: validation of a symbolic ray-tracing method on synthetic data / Fabien Coubard (2011)
contenu dans Photogrammetric image analysis PIA 11, Munich, Germany, October 5-7, 2011 / Uwe Stilla (2011)
Titre : Reflectance estimation from urban terrestrial images: validation of a symbolic ray-tracing method on synthetic data Type de document : Article/Communication Auteurs : Fabien Coubard , Auteur ; Mathieu Brédif , Auteur ; Nicolas Paparoditis , Auteur ; Xavier Briottet , Auteur Editeur : International Society for Photogrammetry and Remote Sensing ISPRS Année de publication : 2011 Collection : International Archives of Photogrammetry, Remote Sensing and Spatial Information Sciences, ISSN 1682-1750 num. 38-3/W22 Conférence : PIA 2011, ISPRS Conference on Photogrammetric Image Analysis 05/10/2011 07/10/2011 Munich Allemagne OA ISPRS Archives Importance : pp 71 - 76 Format : 21 x 30 cm Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] correction radiométrique
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] éclairement lumineux
[Termes IGN] image numérique
[Termes IGN] image terrestre
[Termes IGN] itération
[Termes IGN] lancer de rayons
[Termes IGN] modèle géométrique de prise de vue
[Termes IGN] problème inverse
[Termes IGN] réflectance spectrale
[Termes IGN] scène urbaineRésumé : (auteur) Terrestrial geolocalized images are nowadays widely used on the Internet, mainly in urban areas, through immersion services such as Google Street View. On the long run, we seek to enhance the visualization of these images. For that purpose, radiometric corrections must be performed to free them from illumination conditions at the time of acquisition. Given the simultaneously acquired 3D geometric model of the scene with LIDAR or vision techniques, we face an inverse problem where the illumination and the geometry of the scene are known and the reflectance of the scene is to be estimated. Our main contribution is the introduction of a symbolic ray-tracing rendering to generate parametric images, for quick evaluation and comparison with the acquired images. The proposed approach is then based on an iterative estimation of the reflectance parameters of the materials, using a single rendering pre-processing. We validate the method on synthetic data with linear BRDF models and discuss the limitations of the proposed approach with more general non-linear BRDF models. Numéro de notice : C2011-037 Affiliation des auteurs : MATIS+Ext (1993-2011) Thématique : IMAGERIE Nature : Communication nature-HAL : ComAvecCL&ActesPubliésIntl DOI : 10.5194/isprsarchives-XXXVIII-3-W22-71-2011 Date de publication en ligne : 26/04/2013 En ligne : https://doi.org/10.5194/isprsarchives-XXXVIII-3-W22-71-2011 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92341 Documents numériques
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Reflectance estimation... - pdf éditeurAdobe Acrobat PDF A comparison of illumination geometry-based methods for topographic correction of QuickBird images of an undulant area / J. Wu in ISPRS Journal of photogrammetry and remote sensing, vol 63 n° 2 (March - April 2008)
[article]
Titre : A comparison of illumination geometry-based methods for topographic correction of QuickBird images of an undulant area Type de document : Article/Communication Auteurs : J. Wu, Auteur ; M. Bauer, Auteur ; D. Wang, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 223 - 236 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse comparative
[Termes IGN] correction d'image
[Termes IGN] détail topographique
[Termes IGN] éclairement lumineux
[Termes IGN] exitance spectrale
[Termes IGN] image Quickbird
[Termes IGN] modèle numérique de surfaceRésumé : (Auteur) The high spatial resolution of QuickBird satellite images makes it possible to show spatial variability at fine details. However, the effect of topography-induced illumination variations become more evident, even in moderately sloped areas. Based on a high resolution (1 m) digital elevation model generated with high-frequency real-time kinematic global position system measurements, this study assessed topographic effects on QuickBird images of an undulant area (with a maximum slope of 7.4°) under different illumination and ground conditions. For land surfaces that were characterized by a non-Lambertian reflection, significant bidirectional variations in spectral radiances were found in all bands. The effectiveness of four illumination geometry-based topographic correction methods was evaluated. The results indicated that the empirical correction was the most effective method for all spectral bands in both solar and view directions, while the cosine correction gave the worst results. The C correction (in the solar direction) and the Minnaert correction reduced topographic effects, but not as effectively as the empirical correction. For the Lambertian, topographic effects were substantial only in the near infrared band in the solar direction. Bidirectional variations of spectral radiances in other bands and/or view directions were minimal and topographic corrections may not be necessary. None of these methods significantly changed the spatial variability of spectral radiances, although the histogram distributions were greatly modified by the cosine correction and the Minnaert correction. Copyright ISPRS Numéro de notice : A2008-116 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2007.08.004 En ligne : https://doi.org/10.1016/j.isprsjprs.2007.08.004 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29111
in ISPRS Journal of photogrammetry and remote sensing > vol 63 n° 2 (March - April 2008) . - pp 223 - 236[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 081-08021 SL Revue Centre de documentation Revues en salle Disponible Comparison of spectral indices obtained using multiple spectroradiometers / K.L. Castro-Esau in Remote sensing of environment, vol 103 n° 3 (15 August 2006)
[article]
Titre : Comparison of spectral indices obtained using multiple spectroradiometers Type de document : Article/Communication Auteurs : K.L. Castro-Esau, Auteur ; G.A. Sanchez-Azofeifa, Auteur ; B. Rivard, Auteur Année de publication : 2006 Article en page(s) : pp 276 - 288 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] analyse comparative
[Termes IGN] éclairement lumineux
[Termes IGN] indice de végétation
[Termes IGN] réflectance spectrale
[Termes IGN] réflectance végétale
[Termes IGN] spectromètre imageurRésumé : (Auteur) To determine the degree of comparability between three spectrometers (Analytical Spectral Devices FieldSpec Pro FR (FR), Analytical Spectral Devices HandHeld (HH), and UniSpec Spectral Analysis System (UN)), leaf spectra of three species (Cafea arabica, Lantana camara, Eriobotrya japonica), recorded from each instrument, were compared using two illumination, viewing, and field of view (FOV) scenarios. Scenario 1 eliminated differences due to illumination, viewing, and FOV conditions. Scenario 2 represented a ‘typical’ illumination and viewing set-up for each instrument. Six vegetation indices were computed from the raw spectra as well as spectra (1) interpolated to 1-nm intervals (the sampling interval of the FR) and (2) interpolated to 3.3 nm (the sampling interval of the UN). The spectra measured from the three instruments differed in both shape and amplitude, more so for scenario 2 than scenario 1. In many cases, indices obtained using one instrument differed significantly from the same indices obtained using the other two instruments (but the same leaves), regardless of scenario. The severity of these differences varied between indices. Interpolation was generally ineffective in ‘matching’ the spectra from the various instruments. Care should be exercised when comparing indices generated from spectra measured from different instruments. Copyright Elsevier Numéro de notice : A2006-332 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2005.01.019 En ligne : https://doi.org/10.1016/j.rse.2005.01.019 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=28056
in Remote sensing of environment > vol 103 n° 3 (15 August 2006) . - pp 276 - 288[article]
Titre : Efficiently acquiring reflectance fields using patterned illumination Type de document : Thèse/HDR Auteurs : Gaurav Garg, Auteur Editeur : Californie [USA] : Stanford University Année de publication : 2006 Importance : 100 p. Format : 21 x 30 cm Note générale : bibliographie
A dissertation submitted to the department of electrical engineering and the committee on graduate studies of Stanford University in partiall fulfillment of the requirements for the degree of Doctor of PhilosophyLangues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] dispersion
[Termes IGN] distribution du coefficient de réflexion bidirectionnelle BRDF
[Termes IGN] données 4D
[Termes IGN] éclairement lumineux
[Termes IGN] flux lumineux
[Termes IGN] matrice symétrique
[Termes IGN] réflectance
[Termes IGN] tenseurIndex. décimale : 24.30 Rayonnement électromagnétique Résumé : (auteur) The use of the reflectance fields of real world objects to render realistic looking images is rapidly increasing. The reflectance field describes the transport of light between the light incident on an object and the light exitant from it. This has numerous applications in areas that include entertainment, cultural heritage, digital libraries and space exploration. The central problem with this approach is the lack of fast methods to acquire the reflectance field data. This dissertation addresses this problem and describes a system for acquiring the reflectance field of real world objects that performs many orders of magnitude faster than the previous approaches. The system models the 8D reflectance field as a transport matrix between the 4D incident light field and the 4D exitant light field. It is a challenging task to measure this matrix because of its large size. However, in some cases the matrix is sparse, e.g. in scenes with little or no inter-reflections. To measure such matrices, this thesis describes a hierarchical technique called dual photography which exploits this sparseness to parallelize the acquisition process. This technique, however, performs poorly for scenes with significant diffuse inter-reflections because in such cases the matrix is dense. Fortunately, in these cases the matrix is often data-sparse. Data-sparseness refers to the fact that sub-blocks of the matrix can be well approximated using low-rank representations. Additionally, the transport matrix is symmetric. Symmetry enables simultaneous measurements from both sides, rows and columns, of the transport matrix. These measurements are used to develop a hierarchical acquisition algorithm that can exploit the data-sparseness by a local rank-1 approximation. This technique, called symmetric photography, parallelizes the acquisition for dense but data-sparse transport matrices. In the process, this thesis introduces the use of hierarchical tensors as the underlying data structure to represent data-sparse matrices, specifically through local rank-1 factorizations of the transport matrix. Besides providing an efficient representation for storage, it enables fast acquisition of the approximated transport matrix and fast rendering of the images from the captured matrix. The prototype acquisition system consists of an array of mirrors and a pair of coaxial projector and camera controlled by a computer. The effectiveness of the system is demonstrated with scenes rendered from reflectance fields that were captured by this system. In these renderings one can change the viewpoint as well as relight objects using arbitrary incident light fields. Note de contenu : 1- Introduction
2- Reflectance Field as the Light Transport Matrix
3- Dual Photography
4- Hierarchical Tensors
5- Symmetric Photography
6- Conclusions and Future WorkNuméro de notice : 24635 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère Note de thèse : PhD Thesis : Electrical engineering : Stanford University : 2006 DOI : sans En ligne : https://graphics.stanford.edu/papers/ggaurav_thesis/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=92231 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 24635-01 THESE Livre LASTIG Dépôt en unité Exclu du prêt A uniform sky illumination model to enhance shading of terrain and urban areas / Patrick Kennelly in Cartography and Geographic Information Science, vol 33 n° 1 (January 2006)
[article]
Titre : A uniform sky illumination model to enhance shading of terrain and urban areas Type de document : Article/Communication Auteurs : Patrick Kennelly, Auteur ; J. Stewart, Auteur Année de publication : 2006 Article en page(s) : pp 21 - 36 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie numérique
[Termes IGN] correction des ombres
[Termes IGN] éclairement lumineux
[Termes IGN] estompage automatique
[Termes IGN] Nevada (Etats-Unis)
[Termes IGN] ombre
[Termes IGN] représentation des détails topographiques
[Termes IGN] système d'information géographique
[Termes IGN] Texas (Etats-Unis)
[Termes IGN] zone urbaineRésumé : (Auteur) Users of geographic information systems (GIS) usually render terrain using a point light source defined by an illumination vector. A terrain shaded from a single point provides good perceptual cues to surface orientation. This type of hill shading, however, does not include any visual cues to the relative height of surface elements. We propose shading the terrain under uniform diffuse illumination, where light arrives equally from all directions of a theoretical sky surrounding the terrain. Surface elements at lower elevations tend to have more of the sky obscured from view and are thus shaded darker. This tinting approach has the advantage that it provides more detailed renderings than point source illumination. We describe two techniques of computing terrain shading under uniform diffuse illumination. One technique uses a GIS-based hill-shading and shadowing tool to combine many point source renderings into one approximating the terrain under uniform diffuse illumination. The second technique uses a C++ computer algorithm for computing the inclination to the horizon in all azimuth directions at all points of the terrain. These virtual horizons are used to map sky brightness to the rendering of the terrain. To evaluate our techniques, we use two Digital Elevation Models (DEMs)-of the Schell Creek Range of eastern Nevada and a portion of downtown Houston, Texas, developed from Light Detection and Ranging (lidar) data. Renderings based on the uniform diffuse illumination model show more detailed changes in shading than renderings based on a point source illumination model. Copyright CaGISociety Numéro de notice : A2006-203 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1559/152304006777323118 En ligne : https://doi.org/10.1559/152304006777323118 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27930
in Cartography and Geographic Information Science > vol 33 n° 1 (January 2006) . - pp 21 - 36[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 032-06011 RAB Revue Centre de documentation En réserve L003 Disponible Development of a robust photogrammetric metrology system for monitoring the healing of bedsores [... pour la surveillance de la guérison des escarres] / A. Malian in Photogrammetric record, vol 20 n° 111 (September - November 2005)PermalinkReconnaissance de matériaux sur des images aériennes en multirecouvrement, par identification de fonctions de réflectances bidirectionnelles / Gilles Martinoty (2005)PermalinkEvaluation of hyperspectral remote sensing as a means of environmental monitoring in the St Austell China clay (kaolin) region, Cornwall, UK / R.J. Ellis in Remote sensing of environment, vol 93 n° 1 (30/10/2004)PermalinkA model-based approach to semi-automated reconstruction of buildings from aerial images / Kourosh Khoshelham in Photogrammetric record, vol 19 n° 106 (June - August 2004)PermalinkA hemispherical-directional reflectance model as a tool for understanding image distinctions between cultivated and uncultivated bare surfaces / J. Cierniewski in Remote sensing of environment, vol 90 n° 4 (30/04/2004)PermalinkHillshading of terrain using layer tints with aspect-variant luminosity / Patrick Kennelly in Cartography and Geographic Information Science, vol 31 n° 2 (April 2004)PermalinkEffets radiométriques en milieu urbain à grande échelle et correction des ombres / Gilles Martinoty in Géomatique expert, n° 32 (01/03/2004)PermalinkEvent-driven SAR data acquisition in urban areas using GIS / Uwe Sörgel in GIS Geo-Informations-Systeme, vol 2003 n° 12 (Dezember 2003)PermalinkA comparison of BRDF models for the normalization of satellite optical data to a standard sun-target-sensor geometry / R. Latifovic in IEEE Transactions on geoscience and remote sensing, vol 41 n° 8 (August 2003)PermalinkPotential and limits of InSAR data for building reconstruction in built-up area / Uwe Stilla in ISPRS Journal of photogrammetry and remote sensing, vol 58 n° 1-2 (June - December 2003)Permalink