Hey Niklas,
Not familiar with BT.2100 PQ but what is the maximum PQ value for Luminance?
160? 180? 200? More?
Best / Roger
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx [mailto:argyllcms-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Niklas Haas
Sent: Friday, February 23, 2018 10:31 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Calibrate to BT.2100 PQ curve?
Hey,
Long time user of ArgyllCMS here. Nothing else comes close, so thanks for the
great tools!
Given the prominence of the BT.2100 PQ (Perceptual Quantizer) standard in HDR
displays and mastering, is it planned to add PQ as a supported gamma type for
`dispcal`?
In principle, the only major difference to the existing curves like `-gs` or
`-g709` is that the response is compared against an absolute scale, rather than
a relative scale. That is, a PQ value of 0.5 (=512 on a 10-bit output) must
always be exactly 92 cd/m² - regardless of the display's measured white point.
Thanks,
Niklas Haas
P.s. I'm not an expert on ICC profiles - but I wonder how HDR ICC profile
generation would be done. Given the fact that SDR ICC profiles are normalized
such that XYZ Y=1 maps to the display's maximum brightness, it probably
wouldn't be wise to do the same for HDR displays. Instead, I'm thinking we
could have Y=1 map to the “nominal”
white (i.e. a signal level of 520 for an ideal PQ display), and use values
above 1 to represent super-highlights. Would this also be possible with
ArgyllCMS?
