Re: colorsync profiles containing 'vcgt' tag
Re: colorsync profiles containing 'vcgt' tag
- Subject: Re: colorsync profiles containing 'vcgt' tag
- From: email@hidden
- Date: Fri, 26 Oct 2001 22:04:06 EDT
In a message dated 10/26/01 8:35:34 PM Eastern Daylight Time,
email@hidden writes:
>
The ColorSync 2.5 documentation shows the 'vcgt' tag
>
has two flavors. Most profiles appear to store gamma
>
as a "formula" having min, max, and gamma parameters
>
for each channel. However it's also possible to store
>
gamma as a table of values. My tool uses the latter,
>
and this seems to fail on OS X. Forwarding to the
>
colorsync-dev list, perhaps someone there can help...
I have found that Acrobat and InDesign also tend to fail with table based
monitor profiles. They seem to read the first number in the table as the
gamma number, and subsequently turn certain images near black. OS X had this
type of issue, turning certain fields black, in earlier releases.I had hoped
that it was resolved at this point...
The upcoming releases of PhotoCAL and OptiCAL should sidestep this issue by
using Gamma numbers instead of tables whenever possible.
C. David Tobie