Re: Epson Photo printers - 16 bit?
Re: Epson Photo printers - 16 bit?
- Subject: Re: Epson Photo printers - 16 bit?
- From: Robert L Krawitz <email@hidden>
- Date: Wed, 16 Jul 2003 20:23:29 -0400
From: email@hidden
Date: Wed, 16 Jul 2003 10:02:36 EDT
In a message dated 7/15/03 9:21:58 PM, email@hidden writes:
> Typically, users send 8-bit per channel RGB files (24-bit total) to
> Epson printers (2200/7600/9600). It *is* possible to send high-bit
> files (16-bit per channel, 48-bit total) and they print very well. The
> question is this: Does anyone know if the high-bit files are massaged
> down to 8-bit files by either the Epson printers or the Epson drivers?
> (or vice versa?) I.e., Is there an advantage to printing high-bit
> files to these printers?
Its the last question that nails it. If you send a 256 level gray
patch RGB file to an Epson inkjet, you get significantly less than
256 levels of gray, and a number of reversals to boot.
Yikes. I don't have convenient access to a Windows box (or Macintosh)
to test this. What I've seen from sample printouts is that Epson's
drivers don't linearize that well, and the result is fairly nasty
posterization in the highlights. Reversals, though?
Still
impressive, however. If you send a 16 bit file with 512 levels of
gray in it (to date I've not created one with more than that) you
don't get any more levels of output than from the 8 bit file.
I need to try this test with Gimp-Print, because it can handle 16 bit
input and there's a test pattern generator that can do all of this.
The experiment would have to be done carefully, though, because the
16-bit input is not linearized (it's assumed to be pre-linearized).
Steve Lawrence would be the list member in a position to confirm
details about inkjet driver functions, but then; he might not be in
a position to comment on the subject.
I don't know anything about Epson's own driver technology, but I'm
quite happy to answer general questions about inkjet drivers and (as
the project lead) specific questions about Gimp-Print's internal
operation.
--
Robert Krawitz <email@hidden>
Tall Clubs International --
http://www.tall.org/ or 1-888-IM-TALL-2
Member of the League for Programming Freedom -- mail email@hidden
Project lead for Gimp Print --
http://gimp-print.sourceforge.net
"Linux doesn't dictate how I work, I dictate how Linux works."
--Eric Crampton
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