images in cross-platform stacks

Richard Gaskin ambassador at fourthworld.com
Wed May 17 02:05:14 EDT 2006


Tereza Snyder wrote:

> On May 16, 2006, at 10:47 PM, Richard Gaskin wrote: 
>> Rev doesn't alter the display of JPEGs or GIFs -- why single out  
>> PNGs in this way, and why try to adjust for screen gamma when the  
>> screen is already doing anything that needs to be done there?
> 
> and Mark Talluto wrote:
> 
>> This is a question that goes way back to the good Dr. Raney.  I  
>> remember having a discussion with him about it.  The details are  
>> fuzzy, but they went something like this:  That is the way it is.
> 
> I seem to remember something too in the dim past. PNGs, I know,  
> contain gamma info in their headers in contrast to JPEGs, which may  
> not. The info is used by rev to display consistent gamma cross-platform.
> 
> In the present, I take advantage of it because it shows, on the Mac,  
> the gamma I can expect in Windows. My applications are wall-to-wall  
> images. I use FireWorks to make most of my images and set it to  
> display Windows gamma. I achieve better control over contrast because  
> I see what (most of) the end users will get.
> 
> It's on purpose!

Fireworks, eh?  One more thing I like about you. :)

It never occured to me that PNGs would try to compensate for differences 
  in gamma.  I guess I'm just one of those old fashioned guys who thinks 
that if a person wants a different gamma they can just change it for 
everything, rather than have some elements not match others.

Why doesn't Mac use the otherwise-industry-standard gamma?

Or perhaps more appropriately now that we're in a world where Apple 
ships with two-button functionality and runs on Intel, WHEN will Apple 
change their default gamma?

I went out on a limb several years ago and predicted the shift to Intel 
and two-button mice for Apple; I'll put myself out there again and 
suggest that Apple may adopt the rest of the world's default gamma 
within 24 months.

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



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