[pdftex] RGB image in pdf inteded for printing.

Hartmut Henkel hartmut_henkel at gmx.de
Mon Dec 10 22:37:07 CET 2007

On Mon, 10 Dec 2007, John Culleton wrote:
> On Monday 10 December 2007 03:51:25 pm Hartmut Henkel wrote:
> > On Mon, 10 Dec 2007, John Culleton wrote:

> > > I know about converting color model via ImageMagick prior to
> > > inclusion but what then is the preferred output format? Tiff is
> > > not an option of course.

> > with tools pnmtotiffcmyk and convert you can create an uncompressed
> > JPEG CMYK graphics file, e. g.:
> > convert foo.png foo.ppm
> > pnmtotiffcmyk foo.ppm > foo.tif
> > convert foo.tif -colorspace CMYK -density 300x300 -quality 100 foo.jpg

> I'll print that out for future reference. Just curious about one
> point: why do you use the suffix ppm instead of pnm?

because .pnm is unspecific about the pixel type (1 or 8 bits? color?
gray? see "man pnm"), whereas .ppm tells explicitly that the output
image shall be multi-bit color pixels; ImageMagick convert knows from
the extension which output image format is wanted. The NetPBM pnmto*
tools instead read the actual input image type from the image header,
they don't care for the extension (often they are used in pipes).

Regards, Hartmut

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