[poppler] Color Management

[Albert Astals Cid]

El Friday 08 August 2008 04:28:22 Hal V. Engel va escriure:
> On Thursday 07 August 2008 06:58:13 pm Leonard Rosenthol wrote:
> > Correct.  You'd need to make MAJOR changes to the rendering
> > architecture of Poppler to do proper color management - especially
> > where transparency is involved.
> >
> > But it would be a very good thing...
> >
> > Leonard
>
> Isn't the use of ICC Profiles in PDFs an integral part of the PDF
> specification?

Sadly there are lots of parts of the PDF spec we don't implement.

>
> If I have an image with a BetaRGB profile embedded into the image (this has
> a wide gamut and unless color managed will not be displayed correctly) as
> part of a PDF how does poppler transform that image to the monitor color
> space?

It does not

>
> I notice in GfxState that there is logic for deciding if an object uses an
> ICC based color space (IE. virtual GfxColorSpaceMode getMode() { return
> csICCBased; }).   If there is no color management support what is being
> done with this information?
>
> Yes it would be a very good thing if poppler had proper color management. 
> In fact I don't understand how any PDF library can bet by without it.  

Because 99.99% of the PDF out there don't use it

> These things are not that hard to do if they are done as part of the
> initial design but are generally difficult to retro fit after the fact.

We did not create poppler from scratch.

> Ok what color space does poppler use for it's output when rendering to a
> monitor (I don't mean RGB I mean what ICC profile describes the color space
> used for this).  Maybe I can take care of this at the applcation level if
> popple renders to a known color space.

Workarounding library bugs/misfeatures at the application level doesn't seem 
the best thing to do to me. Patches for implementing ICC color profiles are 
more than welcome.

Albert

>
> Hal
>
> > On Aug 7, 2008, at 1:33 PM, Albert Astals Cid wrote:
> > > A Dijous 07 Agost 2008, Hal V. Engel va escriure:
> > >> I am looking at adding color managed display of PDF files to an
> > >> application
> > >> that is using poppler.  But I have not found much in the way of
> > >> documentation for the poppler API.  Is there documentation on how
> > >> to setup
> > >> poppler so that it will use monitor ICC profiles to correctly
> > >> display PDF
> > >> documents?  If not is there a piece of code that does this that
> > >> someone can
> > >> point out to me?
> > >
> > > As far as i know we don't support color management at all.
> > >
> > > Albert
> > >
> > >> Hal
> > >
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