Re: ColorSync and printing -- Panther (2 of 2)
Re: ColorSync and printing -- Panther (2 of 2)
- Subject: Re: ColorSync and printing -- Panther (2 of 2)
- From: Matt Deatherage <email@hidden>
- Date: Fri, 19 Dec 2003 11:03:05 -0600
On 12/19/03 at 5:07 AM, Rolf Gierling <email@hidden> wrote:
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John Zimmerer wrote:
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>"Standard" uses ColorSync to convert from the source color
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>in your documents to a single output profile, and sends
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>pre-matched device data to the printer/RIP. This is the
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>same as choosing "ColorSync color matching" in the
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>LaserWriter 8 driver on Mac OS 9.
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....
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>b) Calibrated source color data are converted to ICC profiles,
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>then passed on as above.
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>
OS 9 did not match EPS colors, still true for Panther or not?
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>5) For raster devices, regardless of driver type (legacy "Tioga"
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>or CUPS), "Standard" (on-host) color matching is always used.
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>
Same question as above.
I'm mostly watching these threads, and am still forming opinions, but these are trick questions. You just didn't know it.
LaserWriter 8 did not color-match EPS images because Mac OS 9 does not see EPS as an "image." When an application prints EPS to a PostScript printer, it just takes the EPS data from the file and injects it into the PostScript stream going to the printer (or file). QuickDraw or Mac OS 9 never see it as an "image." It's never rasterized and never turned into pixels, so there's no opportunity for color matching.
For it to work any other way, the path from EPS to PostScript stream would have to involve a real PostScript interpreter that examined the EPS data for colors so the driver could insert some kind of color adjustment or dictionary. That's not how EPS has ever worked on the Macintosh - it's just a black box of PostScript data that goes from a file on disk to the PostScript stream without examination or alteration, because the OS does not include a PostScript interpreter/RIP.
Interestingly, Mac OS X 10.3 does include the Adobe Normalizer, so applications that want to could change EPS to PDF without losing resolution-independence. I do not know, however, if the Normalizer will recognize any color dictionaries in an EPS image and bring them along to PDF. At the least, though, an application converting EPS to PDF would have the chance to insert any ColorSync profiles it wanted in the PDF image.
However, even Panther can't do automatic color matching for any application that continues to print EPS data simply by injecting it into a PostScript stream. Panther never sees that data as an image, just a bunch of text/binary data added to a printing stream.
And, just to remind everyone how odd all of this is, you _might_ get EPS color matching under Mac OS 9 (or even Mac OS X) when printing to a NON-PostScript device. For raster devices, all an application can do is use the "preview" data in the EPS file, usually a 'PICT' image. If that image has an embedded profile and the application uses it properly, you could get that color-matching when printing to an inkjet printer, but none when printing to a gigantic PostScript RIP.
Unlikely, perhaps, but at least possible.
--Matt
--
Matt Deatherage <email@hidden> <
http://www.macjournals.com>
I read this list in digest mode; copy me privately for faster responses
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