DOC: Mantis-942: document the GDALImageIO to explain why default origin is set to [0.5,0.5].
DOC: Mantis-942: document the GDALImageIO to explain why default origin is set to [0.5,0.5].

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