Please use this identifier to cite or link to this item: http://repositorio.ufla.br/jspui/handle/1/12479
Title: Medidas de acurácia baseada em objeto: análise metodológica em relação à validação baseada em pixel
Other Titles: Object-based accuracy assessment: methodological analysis in relation to pixel-based validation
Authors: Carvalho, Luis Marcelo Tavares de
Volpato, Margarete Marin Lordelo
Oliveira, Luciano Teixeira de
Keywords: Mapas – Projeção
Análise orientada a objeto
Análise baseada em pixel
Sensoriamento remoto
Map projection
Object-based image analysis
Pixel-based image analysis
Remote sensing
Issue Date: 20-Mar-2017
Publisher: Universidade Federal de Lavras
Citation: PRADO, D. F. C. do. Medidas de acurácia baseada em objeto: análise metodológica em relação à validação baseada em pixel. 2016. 112 p. Dissertação (Mestrado em Engenharia Florestal)-Universidade Federal de Lavras, Lavras, 2016.
Abstract: The generation of thematic maps using images of high spatial resolution, applied to the new methodologies of analysis based on geographic object (GEOBIA), promotes a significant gain in the quality of land cover information. In addition, the maps generated from this approach bring great advantages over pixel-based analysis, especially in relation to the accuracy of the final map. The accuracy indexes used for the evaluation of these cartographic products are still obtained from the traditional validation, based on pixel. With the absence of a validation that represents the geographic object, new methodologies of object-based accuracy have been developed, such as the STEP similarity matrix. Therefore, the objective of this study was to compare an object-based validation methodology, in relation to the traditional pixel-based methodology, to evaluate the thematic land cover mapping. The study area includes part of the Lavras, Perdões, Ijaci, Bom Sucesso, Itumirim, Itutinga and Ibituruna counties, in the Minas Gerais State. The land cover map was generated from the RapidEye Image, acquired on 06/30/2011, with 5 meters of spatial resolution. The classification overall accuracy in relation to the traditional confusion matrix was 91.7% and 0.83 for the Kappa index. The reference objects used in object-based validation were vectored based on the targets that were contemplated by points, based on the same RapidEye image. The methodology used integrates four similarity measures (shape, theme, border and position) that result in three error matrices (individual and aggregated by thematic class and aggregated by weighted area). A global accuracy was obtained for the thematic similarity (82.25%) and for the similarity measures of position (89.93%), edge (98.47%) and shape (90.86%). The accuracy results of the producer and the traditional validation user, based on pixel, presented sub and overestimations among the classes mapped in relation to the similarity object-based accuracy, mainly between vegetation classes and anthropic area. The applied methodology is efficient in the evaluation of the objects and present great gains regarding the traditional validation, as much in relation to the thematic as geometric analysis.
URI: http://repositorio.ufla.br/jspui/handle/1/12479
Appears in Collections:Engenharia Florestal - Mestrado (Dissertações)

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