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Parallel performance of typical algorithms in remote sensing-based mapping on a multi-core computer / Jinghui Yang in Photogrammetric Engineering & Remote Sensing, PERS, vol 81 n° 5 (May 2015)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 81 n° 5 (May 2015) . - pp 373 - 385 Titre : Parallel performance of typical algorithms in remote sensing-based mapping on a multi-core computer Type de document : Article/Communication Auteurs : Jinghui Yang, Auteur ; Jixian Zhang, Auteur Année de publication : 2015 Article en page(s) : pp 373 - 385 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] processeur multicoeur [Termes IGN] traitement d'image [Termes IGN] traitement parallèle Résumé : (auteur) Typical algorithms in remote sensing-based mapping, such as geometric correction, image fusion, image mosaic, and automatic DEM extractions, are data- and computation-intensive; processing on multi-core computers can improve their performance. Therefore, parallel computing methods that can fully leverage state-of-the-art hardware platforms and that can be easily adapted to these algorithms are required. In this paper, a method with high parallelism is adopted. The method integrates a recursive procedure with a parallel mechanism that is capable of concurrently processing multiple blocks on multiple cores. The parallel experiments of five categories of typical algorithms on two multi-core computers with Windows and Linux operating systems, respectively, were fulfilled. The experimental results show that although the gains of parallel performance vary for different algorithms, the processing performance achieved on multi-core computers is significantly improved. The best case on a computer with two CPUs is able to perform the DEM extractions up to 13.6 times faster than serial execution. According to these experiments, the factors influencing parallel performance on a multi-core computer are discussed. Numéro de notice : A2015-972 Affiliation des auteurs : non IGN Thématique : IMAGERIE/INFORMATIQUE Nature : Article DOI : 10.14358/PERS.81.5.373 En ligne : https://doi.org/10.14358/PERS.81.5.373 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80042 [article]

Evaluation of Lidar-derived DEMs through terrain analysis and field / Cody P. Gillin in Photogrammetric Engineering & Remote Sensing, PERS, vol 81 n° 5 (May 2015)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 81 n° 5 (May 2015) . - pp 387 - 396 Titre : Evaluation of Lidar-derived DEMs through terrain analysis and field Type de document : Article/Communication Auteurs : Cody P. Gillin, Auteur ; Scott W. Bailey, Auteur ; Kevin J. McGuire, Auteur ; Stephen P. Prisley, Auteur Année de publication : 2015 Article en page(s) : pp 387 - 396 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] bassin hydrographique [Termes IGN] crète (ligne) [Termes IGN] données lidar [Termes IGN] données localisées 3D [Termes IGN] filtre passe-bas [Termes IGN] modèle numérique de surface [Termes IGN] pas d'échantillonnage au sol [Termes IGN] pente Résumé : (auteur) Topographic analysis of watershed-scale soil and hydrological processes using digital elevation models (DEMs) is commonplace, but most studies have used DEMs of 10 m resolution or coarser. Availability of higher-resolution DEMs created from light detection and ranging (lidar) data is increasing but their suitability for such applications has received little critical evaluation. Two different 1 m DEMs were re-sampled to 3, 5, and 10 m resolutions and used with and without a low-pass smoothing filter to delineate catchment boundaries and calculate topographic metrics. Accuracy was assessed through comparison with field slope measurements and total station surveys. DEMs provided a good estimate of slope values when grid resolution reflected the field measurement scale. Intermediate scale DEMs were most consistent with land survey techniques in delineating catchment boundaries. Upslope accumulated area was most sensitive to grid resolution, with intermediate resolutions producing a range of UAA values useful in soil and groundwater analysis. Numéro de notice : A2015-973 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.81.5.387 En ligne : https://doi.org/10.14358/PERS.81.5.387 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80043 [article]

Refining high spatial resolution remote sensing image segmentation for man-made objects through acollinear and ipsilateral neighborhood model / Min Wang in Photogrammetric Engineering & Remote Sensing, PERS, vol 81 n° 5 (May 2015)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 81 n° 5 (May 2015) . - pp 397 - 406 Titre : Refining high spatial resolution remote sensing image segmentation for man-made objects through acollinear and ipsilateral neighborhood model Type de document : Article/Communication Auteurs : Min Wang, Auteur ; Yanxia Sun, Auteur ; Guanyi Chen, Auteur Année de publication : 2015 Article en page(s) : pp 397 - 406 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse d'image orientée objet [Termes IGN] détail topographique artificiel [Termes IGN] détection d'objet [Termes IGN] planimétrie [Termes IGN] pouvoir de résolution géométrique [Termes IGN] segmentation d'image Résumé : (auteur) Man-made objects, such as buildings and roads, which are important targets for information extraction from high spatial resolution (HSR) remote sensing images, often feature straight boundaries. This study employs this knowledge on HSR image segmentation by embedding a straight-line constraint in regionbased image segmentation. A new concept called collinear and ipsilateral neighborhood is proposed and applied to hardboundary constraint-based image segmentation for accuracy improvement. In the experimental areas, the method accuracy measured by recall ratio r increases from 0.036 to 0.048 (on the average) after the refinement, with significantly smaller decreases in precision p that are all less than 0.006. In sum, the proposed technique effectively reduces over-segmentation errors and maintains the same level of under-segmentation error ratio, particularly in man-made areas. It facilitates subsequent objectbased image analyses, including feature extraction, object recognition, and classification. Numéro de notice : A2015-974 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : doi.org/10.14358/PERS.81.5.397 En ligne : https://doi.org/10.14358/PERS.81.5.397 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80044 [article]

Lidar detection of the ten tallest trees in the Tennessee portion of the Great Smoky Mountains national park / Chris W. Strother in Photogrammetric Engineering & Remote Sensing, PERS, vol 81 n° 5 (May 2015)  

Public [article]  inPhotogrammetric Engineering & Remote Sensing, PERS > vol 81 n° 5 (May 2015) . - pp 407 - 413 Titre : Lidar detection of the ten tallest trees in the Tennessee portion of the Great Smoky Mountains national park Type de document : Article/Communication Auteurs : Chris W. Strother, Auteur ; Marguerite Madden, Auteur ; Thomas R. Jordan, Auteur ; Andrea Presotto, Auteur Année de publication : 2015 Article en page(s) : pp 407 - 413 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie [Termes IGN] arbre (flore) [Termes IGN] arbre remarquable [Termes IGN] hauteur des arbres [Termes IGN] lever mobile [Termes IGN] modèle numérique de surface [Termes IGN] parc naturel [Termes IGN] Tennessee (Etats-Unis) Résumé : (auteur) This paper describes a method for predicting the locations and heights of the ten tallest trees in the Tennessee portion of the Great Smoky Mountains National Park. Iterative computation tools were utilized to process the data along with the lidar derived bare earth digital elevation models and digital surface models to create canopy height models for the Tennessee portion of the park. A height threshold of 51.8 meters was chosen as the minimum value for a tree of extraordinary height. Ten potential sites containing tall trees were identified using this methodology, and seven of the top ten ranking trees’ heights were field measured using accepted forestry methodology. The trees detected using these methods are potentially the tallest trees ever measured on the East Coast of the United States. These methods show that unique tall trees can be successfully detected in a large, heterogeneous forest area using lidar data. Numéro de notice : A2015-975 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.14358/PERS.81.5.407 En ligne : https://doi.org/10.14358/PERS.81.5.407 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=80045 [article]