BUG: when no training polygons are found, this is an error, not a warning
BUG: when no training polygons are found, this is an error, not a warning

orfeotoolbox/OTB,orfeotoolbox/OTB,orfeotoolbox/OTB,orfeotoolbox/OTB,orfeotoolbox/OTB,orfeotoolbox/OTB