Add missing schema ImBack camera maker

[kmilos]

Cf. recent commit 59cf9f9

Should it be "ImBack" or "Imback"? We left GoPro, OnePlus, etc. alone AFAICT?

[LebedevRI]

I'm reasonably sure i just used what was in the DNG provided by the linked tool.
To be fully honest, i do not particularly understand this name normalization/sanitization,
it's rules really need to be documented.

[LebedevRI]

Thank you!

[kmilos]

To be fully honest, i do not particularly understand this name normalization/sanitization,
it's rules really need to be documented.

Yeah, I think the dngmeta.sh script does a blind sentence capitalization for the rawspeed internal ID maker attribute (this was to handle and prettify NIKON, RICOH, SONY, etc.), so there is still a need to double-check this manually...