Screen gamma and PNG files

[Richard Gaskin]

Chipp Walters wrote:

> Richard Gaskin wrote:
>
>> Great work on that gamma stack, Chipp.
>>
>> Oddly enough though, I keep my Mac at PC gamma (2.2) but the engine 
>> reports my screengamma as "1.7" -- any clue as to why the engine would 
>> differ from what my OS X Display settings tell me?
> 
> I'm thinking the RR engine is not *that* smart. It's just seeing "Mac" 
> and reporting 1.7. I think that stuff was programmed before OSX and 
> Mac's ability to have a PC gamma. Though, I must say, even the Mac set 
> at PC gamma is still much lighter than standard PC gamma.

The ability to calibrate and change gamma has been around since at least 
v9.0, likely earlier. It may have been hidden in the ColorSynch control 
panel (Apple loves their trademarks).

In OS X 10.3.5, when I change my Mac to have a 2.2 gamma all three of 
the images in your same stack match perfectly (or as perfectly as my 
eyes can see).

Maybe I've just been working in 2.2 for too many years, but when I 
change my Mac to use it's "standard" Mac setting it looks to bright, 
almost washed out.

There may have been a historical justification for not using the same 
setting as the other 97% of the world (well, back then it was just 90% 
of the world <g>), but given that today everything from motion pictures 
to photojournalism is done on other systems too it would seem a good 
time for Apple to consider playing nice on this one and migrate to the 
de facto universal standard (hey, I can dream can't I?).

-- 
  Richard Gaskin
  Fourth World Media Corporation
  ___________________________________________________________
  Ambassador at FourthWorld.com       http://www.FourthWorld.com