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Titre : Light Field Photography with a Hand-Held Plenoptic Camera Type de document : Rapport Auteurs : Ren Ng, Auteur ; Marc Levoy, Auteur ; Mathieu Brédif , Auteur ; Gene Duval, Auteur ; Mark Horowitz, Auteur ; Pat Hanrahan, Auteur Editeur : Californie [USA] : Stanford University Année de publication : 2005 Importance : 11 p. Note générale : bibliographie
Computer Science Tech Report, Rapport de recherche 2005-02, number 2005-02 - Apr 2005Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] image numériqueRésumé : (auteur) This paper presents a camera that samples the 4D light field on its sensor in a single photographic exposure. This is achieved by inserting a microlens array between the sensor and main lens, creating a plenoptic camera. Each microlens measures not just the total amount of light deposited at that location, but how much light arrives along each ray. By resorting the measured rays of light to where they would have terminated in slightly different, synthetic cameras, we can compute sharp photographs focused at different depths. We show that a linear increase in the resolution of images under each microlens results in a linear increase in the sharpness of the refocused photographs. This property allows us to extend the depth of field of the camera without reducing the aperture, enabling shorter exposures and lower image noise. Especially in the macrophotography regime, we demonstrate that we can also compute synthetic photographs from a range of different viewpoints. These capabilities argue for a different strategy in designing photographic imaging systems. To the photographer, the plenoptic camera operates exactly like an ordinary hand-held camera. We have used our prototype to take hundreds of light field photographs, and we present examples of portraits, high-speed action and macro close-ups. Numéro de notice : 17771 Affiliation des auteurs : MATIS+Ext (1993-2011) Thématique : IMAGERIE/INFORMATIQUE Nature : Rapport de recherche DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=103486 Documents numériques
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Titre : Modelling of spaceborne linear array sensors Type de document : Thèse/HDR Auteurs : Daniela Poli, Auteur Editeur : Zurich : Institut für Geodäsie und Photogrammetrie IGP - ETH Année de publication : 2005 Collection : IGP Mitteilungen, ISSN 0252-9335 num. 85 Importance : 204 p. Format : 21 x 30 cm ISBN/ISSN/EAN : 978-3-906467-50-4 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] auto-étalonnage
[Termes IGN] C (langage)
[Termes IGN] capteur aérien
[Termes IGN] capteur en peigne
[Termes IGN] capteur spatial
[Termes IGN] chambre DTC
[Termes IGN] compensation par faisceaux
[Termes IGN] géométrie de l'image
[Termes IGN] géoréférencement direct
[Termes IGN] géoréférencement indirect
[Termes IGN] GPS-INS
[Termes IGN] image EROS
[Termes IGN] image MOMS-2P
[Termes IGN] image SPOT-HRS
[Termes IGN] image Terra-ASTER
[Termes IGN] image Terra-MISR
[Termes IGN] modèle géométrique de prise de vue
[Termes IGN] modèle mathématique
[Termes IGN] modèle par fonctions rationnelles
[Termes IGN] modèle stéréoscopique
[Termes IGN] orientation du capteur
[Termes IGN] orientation externe
[Termes IGN] orientation interne
[Termes IGN] point d'appui
[Termes IGN] point de vérification
[Termes IGN] points homologuesIndex. décimale : 35.11 Géométrie et qualité des prises de vues Résumé : (Auteur) The topic of this research is the development of a mathematical model for the georeferencing of imagery acquired by multi-line CCD array sensors, carried on air- or spacecraft. Linear array sensors are digital optical cameras widely used for the acquisition of panchromatic and multispectral images in pushbroom mode with spatial resolution ranging from few centimeters (airborne sensors) up to hundreds meters (spaceborne sensors). The images have very high potentials for photogrammetric mapping at different scales and for remote sensing applications. For example, they can be used for the generation of Digital Elevation Models (DEM), that represent an important basis for the creation of Geographic Information Systems, and the production of 3D texture models for visualization and animation purposes.
In the classical photogrammetric chain that starts from the radiometric preprocessing of the raw images and goes to the generation of products like the DEMs, the orientation of the images is a fundamental step and its accuracy is a crucial issue during the evaluation of the entire system. For pushbroom sensors, the triangulation and photogrammetric point determination are rather different compared to the standard approaches for full frame imagery and require special investigations on the sensor geometry and the acquisition mode.
Today various models based on different approaches have been developed, but few of them are rigorous and can be used for a wide class of pushbroom sensors. In general a rigorous sensor model aims to describe the relationship between image and ground coordinates, according to the physical properties of the image acquisition. The functional model is based on the collinearity equations. The sensor model presented in this thesis had to fulfil the requirement of being rigorous and at the same time as flexible as possible and adaptable to a wide class of linear array sensors. In fact pushbroom scanners in use show different geometric characteristics (optical systems, number of CCD lines, scanning mode, stereoscopy) and for each data set specific information are available (ephemeris, GPS/INS observations, calibration, other internal parameters). Therefore the model needs to be dependent on a certain number of parameters that may change for each sensor.
According to the availability of information on the sensor internal and external orientation, the proposed model includes two different orientation approaches.
The first one, the direct georeferencing one, is based on the estimations of the ground coordinates of the points measured in the images through a forward intersection, using the external orientation provided by GPS and INS instruments or interpolated by ephemeris or computed using the orbital parameters (satellite case). This approach does not require any ground control points, except for final checking, and does not estimate any additional parameters for the correction of the interior and exterior orientation. For this reason, the accuracy of this method depends on the accuracy of the external and internal orientation data.
The alternative orientation method, based on indirect georeferencing, is used if the sensor external and internal orientation is not available or not enough accurate for high-precision photograrnmetric mapping. This approach is a self-calibrating bundle adjustment. The sensor position and attitude are modelled with 2nd order piecewise polynomial functions (PPM) depending on time. Constraints on the segment borders assure the continuity of the functions, together with their first and second derivatives. Using pseudo-observations on the PPM parameters, the polynomial degree can be reduced to one (linear functions) or even to zero (constant functions). If GPS and INS are available, they are integrated in the PPM. For the self-calibration, additional parameters (APs) are used to model the lens internal parameters and distortions and the linear arrays displacements in the focal plane.
The parameters modelling the internal and external orientation, together with the ground coordinates of tie and control points, are estimated through a least-squares bundle adjustment using well distributed ground control points. The use of pseudo-observations allows the user to run the adjustment fixing any unknown parameters to certain values. This option is very useful not only for the external orientation modelling, but also for the analysis of the single self-calibration parameter's influence. The weights for the observations and pseudo-observations are determined according to the measurement accuracy. A blunder detection procedure is integrated for the automatic detection of wrong image coordinate measurement. The adjustment results are analyzed in terms of internal and external accuracy. The APs to be estimated are chosen according to their correlations with the other unknown parameters (ground coordinates of tie points and PPM parameters). A software has been developed under Unix environment in C language.
The flexibility of the model has been proved by testing it on MOMS-2P, SPOT-5/HRS, ASTER, MISR and EROS-A1 stereo images. These sensors have different characteristics (single-lens and multi-lens optical systems, various number of linear arrays, synchronous and asynchronous acquisition modes), covering a wide range of possible acquisition geometries.
For each dataset both the direct and indirect models have been used and in all cases the direct georeferencing was not accurate enough for high accurate mapping. The indirect model has been applied with different ground control points distributions (when possible), varying the PPM configurations (number of segments, polynomials degree) and with and without self-calibration. Excluding EROS-A1, all the imagery has been oriented with sub-pixels accuracy in the check points using a minimum of 6 ground control points. In case of EROS-A1, an accuracy in the range of I to 2 pixels has been achieved, due the lack of information on the geometry of the sensor asynchronous acquisition. For the ASTER and SPOT-5/HRS datasets, a DEM has also been generated and compared to some reference DEMs.
New cameras can be easily integrated in the model, because the required sensor information are accessible in literature as well as in the web. If no information on the sensor internal orientation is available, the model supposes that the CCD lines are parallel to each other in the focal plane and perpendicular to the flight direction and estimates any systematic error through the self-calibration. The satellite's position and velocity vectors, usually contained in the ephemeris, are required in order to compute the initial approximations for the PPM parameters. If this information is not available, the Keplerian elements can be used to estimate the nominal trajectory. For pushbroom scanners carried on airplane or helicopter the GPS and INS measurements are indispensable, due to the un-predictability of the trajectory.Note de contenu : 1. INTRODUCTION
1.1. REVIEW OF EXISTING MODELS
1.2. RESEARCH OBJECTIVES
1.3. OUTLINE
2. LINEAR CCD ARRAY SENSORS
2.1. SOLIDSTATE TECHNOLOGY
2.2. ARRAY GEOMETRIES
2.2. 1. Linear arrays
2.2.2. Other geometries
2.3. IMAGING SYSTEM
2.4. SENSOR CALIBRATION
2.4.1. Errors in CCD lines
2.4.2. Lens distortions
2.4.3. Laboratory calibration
2.5. STEREO ACQUISITION
2.5.1. Acrosstrack
2.5.2. Alongtrack
2.6. PLATFORMS
2.6.1. Satellite platforms
2.6.2. Airborne and helicopter platforms
2.7. IMAGE CHARACTERISTICS
2.7.1. Spatial resolution
2.7.2. Radiometric resolution
2.7.3. Spectral resolution
2.7.4. Temporal resolution
2.8. PROCESSING LEVELS
2.9. LIST OF LINEAR ARRAY SENSORS
2.10. CONCLUSIONS
3. DIRECT GEOREFERENCING
3.1. EXTERNAL ORIENTATION FROM GPS/INS
3.1.1. Background
3.1.2. GPS system
3.1.3. INS system
3.1.4. GPS/INS integration
3.1.5. Commercial systems
3.2. EXTERNAL ORIENTATION FROM EPHEMERIS
3.2.1. Orientation with Keplerian elements
3.2.2. Orientation from state vectors
3.2.3. Interpolation between reference lines
3.3. DIRECT GEOREFERENCING
3.3.1. From image to camera coordinates
3.3.2. From camera to ground coordinates
3.3.3. Estimation of approximate ground coordinates
3.3.4. Refinement
3.4. SOME CONSIDERATIONS ON GPS/INS MEASUREMENTS
3.5. ACCURACY EVALUATION
3.6. CONCLUSIONS
4. INDIRECT GEOREFERENCING
4.1. ALGORITHM OVERVIEW
4.2. EXTENTION TO MULTILENS SENSORS
4.3. EXTERNAL ORIENTATION MODELLING
4.3.1. Integration of GPS/INS observations
4.3.2. Function continuity
4.3.3. Reduction of polynomial order
4.4.SELFCALIBRATION
4.5. OBSERVATION EQUATIONS
4.5.1. Image coordinates
4.5.2. External orientation parameters
4.5.3. Selfcalibration parameters
4.5.4. Ground control points
4.6. LEAST SQUARES ADJUSTMENT
4.6.1. Theory of least squares adjustment
4.6.2. Linearization
4.6.3. Design matrix construction
4.6.4. Solution of linear system
4.7. ANALYSIS OF RESULTS
4.7.1. Internal accuracy
4.7.2. RMSE calculations
4.7.3. Correlations
4.7.4. Blunder detection
4.8. FORWARD INTERSECTION
4.9. SUMMARY AND COMMENTS
5. PREPROCESSING
5.1. METADATA FILES FORMATS
5.2. INFORMATION EXTRACTION FROM METADATA FILES
5.3. RADIOMETRIC PREPROCESSING
5.3.1. Standard algorithms
5.3.2. Adhoc filters
6. APPLICATIONS
6.1. WORKFLOW
6.2. MOMS02
6.2.1. Sensor description
6.2.2. Data description
6.2.3. Preprocessing
6.2.4. Image orientation
6.2.5. Summary and conclusions
6.3. SPOT5/HRS
6.3.1. Sensor description
6.3.2. Data description
6.3.3. Preprocessing
6.3.4. Image orientation
6.3.5. DEM generation
6.3.6. Comparison
6.3.7. Summary and conclusions
6.4 ASTER
6.4.1. Sensor description
6.4.2. Data description
6.4.3. Preprocessing
6.4.4. Images orientation
6.4.5. DEM generation
6.4.6. Comparison with reference DEMs
6.4.7. Summary and conclusions
6.5 MISR
6.5.1. Sensor description
6.5.2. Data description
6.5.3. Preprocessing
6.5.4. Image orientation
6.5.5. Summary and conclusions
6.6 EROS-A1
6.6.1. Sensor description
6.6.2. Data description and Preprocessing
6.6.3. Image orientation
6.6.4. Summary and conclusions
7. CONCLUSION AND OUTLOOK
7.1 CONCLUSION
7.2 OUTLOOKNuméro de notice : 13260 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse étrangère DOI : 10.3929/ethz-a-004946341 En ligne : http://dx.doi.org/10.3929/ethz-a-004946341 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=54943 Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 13260-01 35.11 Livre Centre de documentation En réserve M-103 Disponible Radarsat-2 to be launched in 2005: features and applications of Canada's second SAR satellite / K. Stephens in GIM international, vol 19 n° 1 (January 2005)
[article]
Titre : Radarsat-2 to be launched in 2005: features and applications of Canada's second SAR satellite Type de document : Article/Communication Auteurs : K. Stephens, Auteur ; G. Staples, Auteur Année de publication : 2005 Article en page(s) : pp 14 - 17 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] image Radarsat
[Termes IGN] limite de résolution géométrique
[Termes IGN] polarimétrie
[Termes IGN] précision métrique
[Termes IGN] radar à antenne synthétique
[Termes IGN] RadarsatRésumé : (Auteur) RADARSAT-2, Canada's second Synthetic Aperture Radar (SAR) Earth observation satellite will offer users imaging flexibility and data information content, ensuring continuity of all existing RADARSAT-1 beam modes along with powerful new capabilities, from 3m resolution to flexibility in selection of polarisation. The satellite is due be launched from Vandenberg Air Force Base in California in 2005. Numéro de notice : A2005-002 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27143
in GIM international > vol 19 n° 1 (January 2005) . - pp 14 - 17[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 061-05011 RAB Revue Centre de documentation En réserve L003 Disponible Robust multiple estimator systems for the analysis of biophysical parameters from remotely sensed data / Lorenzo Bruzzone in IEEE Transactions on geoscience and remote sensing, vol 43 n° 1 (January 2005)
[article]
Titre : Robust multiple estimator systems for the analysis of biophysical parameters from remotely sensed data Type de document : Article/Communication Auteurs : Lorenzo Bruzzone, Auteur ; F. Melgani, Auteur Année de publication : 2005 Article en page(s) : pp 159 - 174 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] estimateur
[Termes IGN] Perceptron multicouche
[Termes IGN] régression
[Termes IGN] réseau neuronal artificiel
[Termes IGN] télédétection spatiale
[Termes IGN] variable biophysique (végétation)Résumé : (Auteur) In this paper, an approach based on multiple estimator systems (MESs) for the estimation of biophysical parameters from remotely sensed data is proposed. The rationale behind the proposed approach is to exploit the peculiarities of an ensemble of different estimators in order to improve the robustness (and in some cases the accuracy) of the estimation process. The proposed MESs can be implemented in two conceptually different ways. One extends the use of an approach previously proposed in the regression literature to the estimation of biophysical parameters from remote sensing data. This approach integrates the estimates obtained from the different regression algorithms making up the ensemble by a direct linear combination (combination-based approach). The other consists of a novel approach that provides as output the estimate obtained by the regression algorithm (included in the ensemble) characterized by the highest expected accuracy in the region of the feature space associated with the considered pattern (selection-based approach). This estimator is identified based on a proper partition of the feature space. The effectiveness of the proposed approach has been assessed on the problem of estimating water quality parameters from multispectral remote sensing data. In particular, the presented MES-based approach has been evaluated by considering different operational conditions where the single estimators included in the ensemble are: 1) based on the same or on different regression methods; 2) characterized by different tradeoffs between correlated errors and accuracy of the estimates; 3) trained on samples affected or not by measurement errors. In the definition of the ensemble particular attention is devoted to support vector machines (SVMs), which are a promising approach to the solution of regression problems. In particular, a detailed experimental analysis on the effectiveness of SVMs for solving the considered estimation problem is presented. The experimental results point out that the SVM method is effective and that the proposed MES approach is capable of increasing both the robustness and accuracy of the estimation process. Numéro de notice : A2005-060 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.839818 En ligne : https://doi.org/10.1109/TGRS.2004.839818 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27198
in IEEE Transactions on geoscience and remote sensing > vol 43 n° 1 (January 2005) . - pp 159 - 174[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-05011 RAB Revue Centre de documentation En réserve L003 Disponible Spatial resolution and processing tradeoffs for HYDROS: application of reconstruction and resolution enhancement techniques / David G. Long in IEEE Transactions on geoscience and remote sensing, vol 43 n° 1 (January 2005)
[article]
Titre : Spatial resolution and processing tradeoffs for HYDROS: application of reconstruction and resolution enhancement techniques Type de document : Article/Communication Auteurs : David G. Long, Auteur Année de publication : 2005 Article en page(s) : pp 3 - 12 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Acquisition d'image(s) et de donnée(s)
[Termes IGN] accentuation d'image
[Termes IGN] bande L
[Termes IGN] capteur (télédétection)
[Termes IGN] humidité du sol
[Termes IGN] HYDROS
[Termes IGN] Hydrospheric State
[Termes IGN] image à basse résolution
[Termes IGN] mission spatiale
[Termes IGN] radiomètre à hyperfréquence
[Termes IGN] reconstruction d'imageRésumé : (Auteur) Recent developments in reconstruction and resolution enhancement for microwave instruments suggest a possible tradeoff between computation, resolution, and downlink data rate based on postcollection reconstruction/resolution enhancement processing. The Hydrospheric State mission is designed to measure global soil moisture and freeze/thaw state in support of weather and climate prediction, water, energy, and carbon cycle studies, and natural hazards monitoring. It will use an active and passive L-band microwave system that optimizes measurement accuracy, spatial resolution, and coverage. The active channels use synthetic aperture radar-type processing to achieve fine spatial resolution, requiring a relatively high downlink data rate and ground processor complexity. To support real-time applications and processing, an optional postcollection reconstruction and resolution enhancement method is investigated. With this option, much lower rate real-aperture radar data are used along with ground-based postprocessing algorithms to enhance the resolution of the observations to achieve the desired 10-km resolution. Several approaches are investigated in this paper. It is determined that a reconstruction/resolution enhancement technique combining both forward- and aft-looking measurements enables estimation of 10-km resolution or better backscatter values at acceptable accuracy. Key tradeoffs to achieve this goal are considered. Numéro de notice : A2005-057 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2004.838385 En ligne : https://doi.org/10.1109/TGRS.2004.838385 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27195
in IEEE Transactions on geoscience and remote sensing > vol 43 n° 1 (January 2005) . - pp 3 - 12[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 065-05011 RAB Revue Centre de documentation En réserve L003 Disponible A new method for cross-calibration of two satellite sensors / J.J. Liu in International Journal of Remote Sensing IJRS, vol 25 n° 23 (December 2004)PermalinkFour years of Landsat-7 on orbit geometric calibration and performance / D. Scott Lee in IEEE Transactions on geoscience and remote sensing, vol 42 n° 12 (December 2004)PermalinkLandsat-5 bumper-mode geometric correction / J.C. Storey in IEEE Transactions on geoscience and remote sensing, vol 42 n° 12 (December 2004)PermalinkLandsat-5 TM reflective-band absolute radiometric calibration / Gyanesh Chander in IEEE Transactions on geoscience and remote sensing, vol 42 n° 12 (December 2004)PermalinkLandsat-7 ETM+ on-orbit reflective-band radiometric characterization / L. Scaramuzza in IEEE Transactions on geoscience and remote sensing, vol 42 n° 12 (December 2004)PermalinkLandsat-7 ETM+ on-orbit reflective-band radiometric stability and absolute calibration / B.L. Markham in IEEE Transactions on geoscience and remote sensing, vol 42 n° 12 (December 2004)PermalinkLandsat sensor performance: history and current status / B.L. Markham in IEEE Transactions on geoscience and remote sensing, vol 42 n° 12 (December 2004)PermalinkFollowing the tour de France with EGNOS / D. Detain in ESA bulletin, n° 120 (01/11/2004)PermalinkThe ISPRS 2004 technical exhibition: Istanbul: airborne imaging dominates the show / Gordon Petrie in Geoinformatics, vol 7 n° 7 (01/11/2004)PermalinkA quantitative measure for the quality of InSAR interferograms based on phase differences / Z. Li in Photogrammetric Engineering & Remote Sensing, PERS, vol 70 n° 10 (October 2004)PermalinkL'altimétrie laser à balayage / Benoît Saint-Onge in Revue internationale de géomatique, vol 14 n° 3 - 4 (septembre 2004 – février 2005)PermalinkHigh resolution mapping with small satellites / R. Sandau in GIS Geo-Informations-Systeme, vol 2004 n° 9 (September 2004)PermalinkIntérêt des données issues du satellite SPOT-5 pour la cartographie des milieux naturels / Anne Jacquin in Revue internationale de géomatique, vol 14 n° 3 - 4 (septembre 2004 – février 2005)PermalinkVicarious radiometric calibration of satellite ocean colour sensors / D. Antoine (01/09/2004)PermalinkDesign and test of the ground-based L-band radiometer for estimating water in soils (LEWIS) / F. LemaÎtre in IEEE Transactions on geoscience and remote sensing, vol 42 n° 8 (August 2004)PermalinkPermalinkA phase signature for detecting wet subsurface structures using polarimetric L-band SAR / Y. Lasne in IEEE Transactions on geoscience and remote sensing, vol 42 n° 8 (August 2004)PermalinkRocsat-2 launched: yet another Asian high-resolution satellite! / Gordon Petrie in Geoinformatics, vol 7 n° 5 (01/08/2004)PermalinkInsights into the affine model for high-resolution satellite sensor orientation / Clive Simpson Fraser in ISPRS Journal of photogrammetry and remote sensing, vol 58 n° 5-6 (July 2004)PermalinkAnalysis of simultaneous chlorophyll measurements by lidar fluorosensor, MODIS and SeaWiFS / R. Bardini in International Journal of Remote Sensing IJRS, vol 25 n° 11 (June 2004)Permalink