[poppler] Implement overprint in qt interface?

Adam Reichold adamreichold at myopera.com
Sun Oct 14 22:26:08 PDT 2012


Hello,

On 14.10.2012 19:50, Thomas Freitag wrote:
> On 14.10.2012 17:23, Adam Reichold wrote:
> Hello Thomas,
> 
> Thanks for the offer. As I understand it, this simulates how the
> actual physical layers of colour would mix in real printing? It does
> sound like a sensible feature to me.
>> No, that's not true. Overprint is a feature already introduced in
>> PostScript and is also defined in the PDF spec, see i.e. chapter 8.6.7
>> as an introduction. But there are only a very few free available viewer
>> which implements it. Beside acrobat reader (and of course poppler :-) )
>> I only know ghostscript which implements it. And even in ghostscript it
>> is not well known because overprint works only in subtractive
>> colorspaces like CMYK, so You have to render in a CMYK-like colorspace
>> and then convert the result to RGB to see it on the monitor. And this is
>> what the just uploaded patch does.

I am not sure I understand how this explanation conflicts with "sensible
feature" as in "it makes sense to have this feature". May be a
misunderstanding? Or do you refer to that it does not simulate the
interaction of physical layers of colour?

Best regards, Adam.

>> Cheers,
>> Thomas
> 
> Why not post the patch to discuss the feature's merits based on that?
> 
> Best regards, Adam.
> 
> On 14.10.2012 13:47, Thomas Freitag wrote:
>>>> Hi folks!
>>>>
>>>> Is there anybody in the community who wants the possibility to
>>>> simulate overprint in qt library? With the implementation of
>>>> DeviceN support in splash this is quite easy now, so I can upload a
>>>> patch. For everybody who doesn't know anything about overprint I
>>>> attach three screenshots which shows the implementation in okular.
>>>> (This is not fake, I made a small apprentice piece today morning
>>>> :-) )
>>>>
>>>> Cheers, Thomas
>>>>
>>>>
>>>> _______________________________________________ poppler mailing
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>>>>
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>>
> 
> 
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