lecture: A complete toolchain for object-based image analysis with GRASS GIS
Object-based image analysis (OBIA) is the current state of the art feature extraction technique for very high resolution (VHR) satellite imagery. While one proprietary tool dominated the market for years, more and more alternative solutions now appear, including free software based, and research continues to produce new approaches. However, many of the techniques implemented in free software are not easily accessible to the inexperienced user. This presentation presents efforts to develop a complete tool chain of easy-to-use modules for OBIA in GRASS GIS, ever since the development of an image segmentation module i.segment during GSoC 2012. Amongst the other modules presented are i.segment.uspo for unsupervised segmentation parameter optimization, i.segment.hierarchical for hierarchical segmentation, v.stats and i.segment.stats for the collection of statistics characterizing the objects, v.class.ml and v.class.mlR for supervised image classification. Combining these modules enables semi-automatic treatment of VHR imagery in a completely free software environment, as shown through examples of the two research projects SmartPop (funded by ISSeP) and MAUPP (funded by BELSPO). The talk will end with some reflections about possible further enhancements of this process, including through the combination of GRASS GIS with other FOSS4G tools.
Links to project: http://grass.osgeo.org (source code: https://grass.osgeo.org/download/software/sources/)