[pdftex] bitmap with clipping path

Stephan Lehmke lehmke at ls1sol02.cs.uni-dortmund.de
Tue Apr 9 14:45:28 CEST 2002

Kester Clegg wrote on 09 Apr 2002 12:25:17 +0100:
> Stephan Lehmke <Stephan.Lehmke at cs.uni-dortmund.de> writes:
> > What I need is this:
> > 
> > In the beginning, there is a photo augmented with a clipping path 
> > in photoshop.
> > 
> > In the end, there is a document processed by pdftex, containing the
> > correctly clipped bitmap underlaid with the special color.
> > 
> > Inbetween, there is any kind of (scriptable) process in which 
> > the photoshop image is made digestible for pdftex...
> > 
> > Photoshop can save in different formats, among them eps, but 
> > it seems neither ghostscript nor distiller can make anything
> > out of the clipping path contained in the eps...
> >
> and pdftex doesn't like eps anyway.

Yea, it's only that I thought if photoshop's pdf isn't fit,
then maybe I could just convert eps to pdf.

> But it does like png, and png can
> handle transparency, or put another way, your alpha channel...

png yes, but can pdftex handle transparency?

Or is there any scriptable tool that could underlay a png image
containing transparency with a pantone background (and save
to something pdftex can understand)?

> > It is also possible to convert the clipping path into a mask
> > (color or alpha channel), but how to process this information?
> >
> So can't you convert your clipping path to an alpha channel, cut, fill
> with your special colour (or use a lower layer, and fade in your clipped
> photo), save output as jpeg or png. 

Er, _can_ a png or jpeg image contain a pantone color?
I didn't know this. Now this would be a simple solution

>  Or if you insist as eps, then use
> epstopdf and then link to the file in your pdf document?

Well as I said, ghostscript (and hence epstopdf) doesn't
support clipping (at least not the stuff photoshop is 
saving to eps).

> Don't try and overlay would be my advice.  Do all your processing first,
> output as jpeg or png and include that.

Do you have an example of a png or jpeg image where cmyk and pantone
colors are combined?

> Wel, you could just embed the pdf produced by photophop into your
> document.  

As I said, photoshop converts the pantone color to cmyk when saving
to pdf, so this is not an option.


  Stephan Lehmke     		 Stephan.Lehmke at cs.uni-dortmund.de
  Fachbereich Informatik, LS I	 Tel. +49 231 755 6434 
  Universitaet Dortmund		 FAX 		  6555
  D-44221 Dortmund, Germany             

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