[software/SfM] Update openMVG_main_ExportUndistortedImages to work with gray images. #773
[software/SfM] Update openMVG_main_ExportUndistortedImages to work with gray images. #773

openMVG/openMVG,openMVG/openMVG,openMVG/openMVG,openMVG/openMVG,openMVG/openMVG