2009-06

What's the best way to manage image metadata?

Stored in the File

Our focus is mostly jpeg (jfif?). There are three methods.

Metadata Working Group is interesting.

exif: Image properties and descriptive metadata. Classic, common, and well supported. Where geolocation stuff lives.
itcp: Industrial strength (predefined subjects, workflow, etc.).
xmp: File format agnostic, rdf'ish, one metadata form to rule them all. The future?

Date and Time

	mwg	digikam
exif
datetime	modification	created
datetimeoriginal	original	original
datetimedigitized	digitized	digitized
iptc
datecreated	original	created
digitizationdate	digitized	digitized
xmp
xmp-modifydate	modification	created
xmp-createdate	digitized	created
xmp-metadatadate		created
exif-datetime		created
exif-datetimeoriginal		original
exif-datetimedigitized		digitized
tiff-datetime		created
photoshop-datecreated	original	created

Application Compatibility

exif

geolocation
no time zones (not needed with geolocation?)
possible round tripping issues

Application Handling

	digikam (0.10.0)		f-spot (0.5.0.3)		gthumb (2.10.11)
	r	w	r	w	r	w
caption (comment)
jfif	✓	✓	−	−	−	−
exif	✓	✓	✓1	✓	~	−
iptc	✓	✓	−	−	✓	✓
xmp	✓	✓	✓2	−	−	−
keyword (tag)
iptc	✓2	✓	✓	−	✓	✓
xmp	✓1	✓	✓	✓	−	−
rating
exif	✓?	✓	−	−	−	−
xmp	✓?	✓	✓	✓	−	−
date time
created (modification)
exif		✓	~?	~	−	−
iptc		✓	−?	−	~	✓
xmp		✓	−?	−	−	−
digitized
exif		✓	−?	−	−	−
iptc		✓	−?	−	−	−
xmp		✓	−?	−	−	−
original
exif	✓	✓	✓?	✓	−	−

Semantic Web / Linked Data