> However, I am a little puzzled by that design choice. I guess (just a gut > feeling) that most people would use softproofing to see the result they > get on a physical medium
That is exactly the point. The profile you are using does NOT represent a physical medium but an idealized color space. If the profile would represent a physical medium, then it will work as you expect. You could also try to use 8 bit instead of floats and cmsFLAGS_NOOPTIMIZE. Regards Marti Maria The LittleCMS project http://www.littlecms.com -----Original Message----- From: Tobias Ellinghaus [mailto:m...@houz.org] Sent: martes, 12 de julio de 2016 12:01 To: lcms-user@lists.sourceforge.net Subject: Re: [Lcms-user] Softproofing with parametric tonecurve On Donnerstag, 23. Juni 2016 19:13:26 CEST Marti Maria wrote: > Ok, I see. A profile created in this way, with primaries and > parametric curves, behaves like a "perfect" profile. That is, it can > be inverted with no loss and its gamut is infinite. You can operate > this profile with negative rgb or xyz values. Or with values well over > 255. And the roundtrip is exact. So, if you tries to emulate which > artifacts the profile causes, the answer is none and this is what you are > getting in your softproofing. > Built-in srgb behaves in same way. > > Another thing is when you flush the profile to disk. Then you are > forcing a quantized representation (in the case of v2) Also, doing > that imposes a gamut because no negative numbers or highlights over L* > 100 are allowed in the file format. Then softproofing shows you the > limitations the file format has. > > So you have to choose whatever the ideal representation and the file based. > > Hope this makes sense to you Thanks, I changed my code to always take a roundtrip through dumping/reading for softproof profiles and it seems to work fine. However, I am a little puzzled by that design choice. I guess (just a gut feeling) that most people would use softproofing to see the result they get on a physical medium – or anything else that clips the colors. Especially when specifying a rendering intent for the transform. Would it be possible to add a transform flag like cmsFLAGS_SOFTPROOFING_CLIPPED that does a clipping in an appropriate place? That might be less surprising and avoid the overhead of creating a new profile on the fly. And maybe document the general issue where softproofing is explained? > Regards > Marti Thank you a lot, even if you don't consider adding what I proposed. lcms is an awesome help and I wouldn't like to do without it. Tobias ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev _______________________________________________ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
