olemus
(1) oseses füüsilises tähenduses

(2) ISO/IEC 19794, ISO/IEC TR 29794 jm: elektroonilisel kujutisel põhinev isiku portree esitus

täpsemalt
http://www.jade1.com/jadecc/courses/UNIVERSAL/NEC05.php?imDif=6489.0

http://www.wjscheirer.com/talks/fg-tutorial-2011_1.pdf

http://egovstandards.gov.in/sites/default/files/Face_Image_Data_Standard_Ver1.0.pdf

https://www.wjscheirer.com/papers/wjs_hrb2009_longrange.pdf

ISO standard
https://www.researchgate.net/publication/264355767_Personal_ID_Image_Normalization_using_ISOIEC_19794-5_Standards_for_Facial_Recognition_Improvement

https://www.researchgate.net/publication/236694457_Face_Image_Conformance_to_ISOICAO_standards_in_Machine_Readable_Travel_Documents

http://sibgrapi.sid.inpe.br/archive.cgi/sid.inpe.br/sibgrapi/2016/07.22.13.57