Re: ColorSync and PostScript printing
Re: ColorSync and PostScript printing
- Subject: Re: ColorSync and PostScript printing
- From: Chris Murphy <email@hidden>
- Date: Fri, 4 Mar 2005 15:34:23 -0700
1.
When I edit the printer manufacturer's CMYK profile and bork it, the
resulting PostScript file is affected in the same manner of my edits.
So I'm inclined to believe that the OS is grabbing the manufacturer
specified profile, and converting data at print time using it.
2.
When I compare a conversion using the same source and destination
profile manually (Photoshop or AppleScript or quartz filters), I get
consistent CMYK values between them. But I get very different CMYK
values in the PostScript file generated by the OS, when it supposedly
uses a (non-borked) manufacturer printer profile.
Something isn't right, and I'm not sure where it is.
3.
Changing the PPD file so that the default color space is RGB, and then
creating a new printer based on that PPD still causes the the document
to be normalized to CMYK (the PostScript spool file is CMYK). So I'm
not sure what this setting does, if anything.
Work around for Uli is to create a quartz filter, with the 3rd option
in the Color tab: "Convert color data to" set to a CMYK profile for the
printer. Then set this filter in the print dialog in the ColorSync
section. And also make sure the ColorSync Utility profile specified for
this device is set to the same profile as the quartz filter, to prevent
double conversion. Embedded profiles are honored. Assumed source
profiles set for quartz filters are always the generic profiles
regardless of the settings used for the filter.
Things I can't answer with the information I have:
a.) Why does the system apparently use the manufacturer profile, but
the CMYK values are not anywhere in the ballpark as a conversion using
supposedly the same source and destination profiles?
b.) The quality of HP's canned CMYK profile for Uli's printer. (i.e.,
if he still gets bad results using the quartz filter approach.)
c.) Whether the printer would behave better if it were profiled RGB.
d.) How to get the OS to normalize a printer job to RGB for this
printer, instead of CMYK.
That's all for now, I've gone over my quota for tracking down weird
problems for the week!
Chris Murphy
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden