- From: Chris Marrin <cmarrin@apple.com>
- Date: Fri, 02 Sep 2011 15:07:03 -0700
- To: Dean Jackson <dino@apple.com>
- Cc: Rik Cabanier <cabanier@gmail.com>, public-fx@w3.org, www-svg <www-svg@w3.org>
On Sep 2, 2011, at 10:44 AM, Dean Jackson wrote: > Hi Rik, > > On 02/09/2011, at 2:53 PM, Rik Cabanier wrote: > >> PDF (and all Adobe apps that create luminosity masks) use 0.03 Red, 0.59 Green, 0.11 Blue which is close to ITU-R BT.601 >> >> Where did you get the values for Flash? > > Good catch! It turns out that I thought I was reading the Flash docs, but I was instead reading the docs for a Flash library. My mistake. > > Also, while admitting that error, I found another since sending that email. The OpenGL values come from informative notes on the OpenGL site - not an official value. Those OpenGL values are computed assuming a Gamma value of 1.0, which is what GL always assumed long ago. I don't think those numbers are meaningful here. > >> Flash content generated from our applications (such as InDesign and Acrobat.com) also use these values. >> I can ask internally where these numbers came from. > > Maybe the question to ask is if the BT.709 values are acceptable? Given that they've been in the spec for a long time (although with a minor difference/error) I think we'd need a good reason to change them dramatically. I wonder what the Adobe SVG Viewer used - the Adobe values or the SVG values? BT.709 is a very well defined spec, used for HDTV. So it seems like a reasonable approach, both for that reason and because it would be the low impedance path. But we should change the numbers to match BT.709. I can't imagine the slight differences in values being an issue. ----- ~Chris cmarrin@apple.com
Received on Friday, 2 September 2011 22:07:55 UTC