-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello,
On 23.10.2012 00:56, Albert Astals Cid wrote: > El Dissabte, 20 d'octubre de 2012, a les 17:36:22, Thomas Freitag > va escriure: >> On 16.10.2012 22:57, Albert Astals Cid wrote: >>> El Dilluns, 15 d'octubre de 2012, a les 07:15:51, Thomas >>> Freitag va > escriure: >>>> On 14.10.2012 22:58, Albert Astals Cid wrote: >>>>> El Diumenge, 14 d'octubre de 2012, a les 19:41:26, Thomas >>>>> Freitag va >>> >>> escriure: >>>>>> On 14.10.2012 17:21, Albert Astals Cid wrote: >>>>>>> El Diumenge, 14 d'octubre de 2012, a les 13:47:29, >>>>>>> Thomas Freitag va >>>>> >>>>> escriure: >>>>>>>> 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. >>>>>>> >>>>>>> Sure, why not? Let's see the patch :-) >>>>>> >>>>>> Okay, here it is. >>>>> >>>>> The two new methods are missing @since markers (and also i >>>>> think the documentation of the two methods could be a bit >>>>> more explanatory) >>>> >>>> @since: I thought that You insert it when You commit it. If I >>>> would insert 0.22.0 You have to change it if You will not >>>> have the time to commit it :-) or I need to change it and >>>> have to upload a new patch if You will not have the time :-( >>> >>> Well, if you do it, it's less work i have to do and thus it's >>> easier i'll have time ;-) >> >> Because I removed these two new methods now there is no need to >> comment them anymore :-) But I introduced a new (static) method >> "okToUseOverprint" which just proofs if poppler is compiled with >> SPLASH_CMYK, and there I add the @since comment now. >> >>>> Explanatory: Okay, but this will be hard. For those who know >>>> what overprint is the documentation is self-explanatory, for >>>> others I need to write reams. What's about to insert the link >>>> to http://en.wikipedia.org/wiki/Overprinting? >>> >>> To be honest doesn't seem to make things much clearer to me :D >> >> Okay, let me try to explain it in my own words: First of all, in >> the normal behaviour, if something is painted everything >> previously painted at this place is knocked out. This is rather >> simplified, because we ignore functionality like transparency, >> blending modes etc. Now let us have a look at the printing >> process with 4 different colour plates Cyan, Magenta, Yellow and >> Black. Without setting the overprint mode, the behaviour is the >> same: if something is painted everything previously painted on >> every plate is knocked out. But when overprint mode is enabled, >> and i.e. in a DeviceN colorspace with only one process colour, >> let us assume Cyan, the Magenta, Yellow and Black plates kept >> untouched and only previously painted objects on the Cyan plate >> at this position are knocked out. But when You paint in >> DeviceCMYK, the behaviour remains the same (all is knocked out) >> even with overprint on, unless You set overprint mode to true in >> addition. With overprint mode true You need to look at the colour >> components You use for painting: if the a component is 0 the >> corresponding colour plate is left untouched again, if it is not >> 0 it will be knocked out again on this colour plate. If there is >> a additional spot colour plate, it is similar: overprint false: >> everything is knocked out, overprint true: if You paint with >> process colours only this spot colour plate is left untouched, if >> You paint with this spot colour, the process colour plates remain >> untouched but on this spot colour plate previously painted >> objects are knocked out. As I said, this is rather simplified, >> there are special rules for images, blending modes and so on and >> so on. A complete explanation can be found in the PDF >> specification. As overprint just works on colour plates, You'll >> see no effects when You print in RGB as on a monitor, therefore >> You have to simulate the effects (overprint preview :-) ) if You >> want to see them on a monitor. >> >>> Ok, let's leave the docu as it is >>> >>>>> Also why are you calling it "overprint preview"? How is it >>>>> a preview? >>>> >>>> To be honest, I haven't really thought about that. Probably I >>>> choose that name because it is also introduced in >>>> GlobalParams with that name. But also in the acrobat reader >>>> preferences it is called "Use overprint preview". And because >>>> not all RIPs support it (i.e. RGB printers) it is indeed >>>> something like a preview (for RIPs which support it). >>> >>> Ok, let's leave it with that name (but maybe make it a >>> RenderingHint as Adam suggests?). >> >> I tried to understand what You meant with RenderingHint and made >> it, hopefully it is what You meant. I attach the changed patches >> (poppler and okular). > > Looks good, I've made some changes (to try to make the roundtrip > faster if you agree to them) > > Rename Document::okToUseOverprint to isOverprintPreviewSupported > like we had for the cms stuff This seems a better way to name it as the old one would suggest it is a per-document property which it is not. > Put back the thing that creates the splashoutputdev and do the same > we do with antialias in the hint changes but for overprint (I don't > really see why we need this code shuffling around, so i'm trying to > minimize the diff size which hopefully minimizes the impact for > other features than this one) While the change is not strictly necessary, the new Document::setRenderHints, Document::getOuputDev and also DocumentData::setPaperColor show why it makes things much simpler. (Looking at the patch: If we add "delete m_outputDev;" to the end of the latter shouldn't there be a "m_outputDev = NULL;" as well?) I also think that there should not be any fallout from this change since the member "DocumentData::m_outputDev" is gone afterwards, hence any code that still relies on a pre-created output device would have been spotted by the compiler. (And there is also Thomas' threading patch which would also introduce those changes to the output device creation.) > Do not set the overprint hint if isOverprintPreviewSupported is > false Makes sense. > Rename the getXBGRPtr to convertToXBGRPtr since it does a lot more > than what you'd expect a getter to do I agree. Best regards, Adam. > What do you think? > > Cheers, Albert > >> >> Cheers, Thomas >> >>> Cheers, >>> >>> Albert >>>>> >>>>> Given that overprint only works if defined(SPLASH_CMYK) you >>>>> should make the setter return a boolean that says if the >>>>> set worked or not (i.e. make it fail if >>>>> !defined(SPLASH_CMYK)) >>>> >>>> Gotcha. I thought about that and disable / enable the option >>>> in okular if the format generator doesn't support it. But >>>> because I'm not familiar enough with okular I defered it and >>>> then forgot it... I'll insert it in QT when I get answers to >>>> the other points. >>>> >>>> Cheers, Thomas >>>> >>>>> Cheers, >>>>> >>>>> Albert >>>>>> >>>>>> In a few places it has already a similar implementation >>>>>> than in bug 50992 (thread safe), because changing the >>>>>> overprint option also meant that we need a different >>>>>> SplashOutputDev instance. But You probably also want to >>>>>> test it in okular? Even if we are here not on an okular >>>>>> list, I attach the okular patch here, too. Also here, it >>>>>> has already the changes from bug 50992. But because >>>>>> POPPLER_QT_THREADSAFE is not defined here, it doesn't >>>>>> make any difference, so I let these changes as they are. >>>>>> BTW, I'm not really familiar with qt programming, so most >>>>>> changes in okular are more or less a (hopefully) best >>>>>> guess. >>>>>> >>>>>> Cheers, Thomas >>>>>> >>>>>>> Cheers, >>>>>>> >>>>>>> Albert >>>>>>>> >>>>>>>> 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 list [email protected] >>>>>>> http://lists.freedesktop.org/mailman/listinfo/poppler >>>>>>> >>>>>>> . >>>>> >>>>> _______________________________________________ poppler >>>>> mailing list [email protected] >>>>> http://lists.freedesktop.org/mailman/listinfo/poppler >>>>> >>>>> . >>>> >>>> _______________________________________________ poppler >>>> mailing list [email protected] >>>> http://lists.freedesktop.org/mailman/listinfo/poppler >>> >>> _______________________________________________ poppler mailing >>> list [email protected] >>> http://lists.freedesktop.org/mailman/listinfo/poppler >>> >>> . >>> >>> >>> _______________________________________________ poppler mailing >>> list [email protected] >>> http://lists.freedesktop.org/mailman/listinfo/poppler -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iQEcBAEBAgAGBQJQhiJIAAoJEPSSjE3STU343GAH/18W/wzaAK38SrIBwa1G8Q6m LBSx1ruQX2pi8+SQ64V/vbEJxK9AptpFxIWS4Qn+5etch6YrN9v7uTu+91qLLuNk JPi91I1Gyk/fMEpW5nKKdZjIpXDNSyM7+rV8a7rESfado9RjKYXrppecmqS1C+pK Ceyd6SYfnAzXs2QVJPcCNLcK9B4GBmCW218bWY6odyxczN3w0M12BNKZpnTZJ+7p 1Hs6RtSeUZVCZdydcqu67rTXdcQwewE0fBic2UREORpQAkGGLTm8afu+gVkqr3hQ /CkV9oBRMx+25RSWgAFILu2xyBSPB/EOap8VSs+BnmyoxY+JAyJeOZNfcl4TpeI= =m0pl -----END PGP SIGNATURE----- _______________________________________________ poppler mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/poppler
