It would allow to use ogr fusion functionalities even with gdal version < 1.8.0
The implementation of the get_lenght method is based on the method available in OGRGeometryCollection class
The behaviour is not modify for otb compiled with gdal > 1.8.0.
The related compiles for now but there are remainig issues with layer deletation in the
related test

ENH: Add new filter otbFusionOGRTileFilter which fusion polygons near tile border. It is used in Synthetize method of otbPersistentImageToOGRDataFilter

ENH: Add option 4Connected/8Connected to GDALPolygonize in LabelImageToVectorDataFilter and LabelImageToOGRDataSourceFilter

ENH: New filter (otbStreamingVectorizedSegmentationOGR) that writes an ogr file as output of a streamed segmentation.

ENH: Add a new filter otbStreamingVectorizedSegmentation which allow stream segmentation and vectorization of the output label image.