cog mediatype at iana

[pvgenuchten]

Has there been any discussion on the use of a dedicated mediatype for COG?

Does it make sense to have a dedicated mediatype, or is it better to tag COG files as regular image/tiff files?

If relevant, are there initiatives to register the cog mediatype at iana?

Question comes from the catalogue world, which wants to reference COG files from metadata records indicating the proper mediatype.

[vincentsarago]

It should be image/tiff; application=geotiff; profile=cloud-optimized

Not sure where it comes from exactly but this has been discussed quite some time ago. FYI it's the one used in STAC https://github.com/stac-utils/pystac/blob/main/pystac/media_type.py#L7

I'm not sure if this was ever registered to Iana. maybe @cholmes knows

[pvgenuchten]

Thanx @vincentsarago, doesit make sense to add this aspect to the specification document?

[vincentsarago]

would be a nice addition yes

[rouault]

I would point this discussion is redundant with opengeospatial/CloudOptimizedGeoTIFF#1 and should maybe be closed in favor of it. The addition of new keys is apparently a no-go for IANA since you can only use keys that were foreseen in the image/tiff registration, but profile might be a special case due to another spec.

[pvgenuchten]

While reading those threads; my impression is that:

• the tiff mediatype as defined at iana does not allow to add alternative parameters then application, so the convention to use profile=cloud-optized is not correct
• suggestion by @EmDevys to replace application=geotiff; profile=cloud-optimized for application=geotiff+cog makes sense
• using a dedicated parameter to differentiate geotiff from tiff can not be registered as such at iana (use of the application parameter is implicit to the image/tiff definition)

+1 to close this issue, and continue on the remote thread