RE: PDF color conversion app
RE: PDF color conversion app
- Subject: RE: PDF color conversion app
- From: Henrik Holmegaard <email@hidden>
- Date: Thu, 25 Jan 2001 08:00:50 +0100
"Broudy, David" <email@hidden> wrote:
PDF 1.2 is not ICC compatible.
right, but I would want to set up such an app to assume all incoming RGB is
Colormatch working space (legit enough, as that's what we're tagging the
scans with in Linocolor) and to use a custom CMYK profile to do the
conversion. would the fact that the incoming PDF is 1.2 preclude this?
unfortunately the files are generated with PDFwriter which cannot write PDF
1.3 files (and it wasn't for lack of trying that I wasn't able to get the
developers to use distiller).
Yes it would.
The point is that PDF 1.2 doesn't allow you to embed ICC profiles at
all. Outgoing files can't be tagged so incoming files don't have
source profiles.
PDF 1.2 has the same color management technology as PostScript Level
2 introduced in 1989 - CSAs for grayscale and RGB while CMYK is
converted to CIELab as Level 2 RIPs prior to version 2017 don't
support a CIEBasedDEFG CSA for CMYK.
PDF 1.2 is not ICC enabled, PDF 1.3 or PDF 1.4 are the way to go.
To create PDF 1.4, use Photoshop 6 if you have nothing else.
PDF is one of those areas where you should pay attention to the dot
version of the format.
(FYI the difference between PDF 1.3 and 1.4 is that 1.4 includes
transparency information which PostScript doesn't. Hence trapping
solutions will migrate to PDF 1.4.)
--
Henrik Holmegaard
TechWrite, Denmark