Re: [Lcms-user] sRGB with unintended D50 whitepoint
marti.ma...@littlecms.com wrote: Hi Marti, > Yes, as Kai-Uwe says, this is the expected behavior for a V4 CMM, and > that is what lcms2 is. Please note most if not all modern CMMs behaves > in such way, for example all Adobe products. Right, but V2 profiles should be processed according to the V2 specifications. Graeme Gill. -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
Re: [Lcms-user] defining TYPE_ABGR_FLT
Hi, >> >> Lcms2 error: 8 Unsupported raster format Yes, this is not supported in 2.3, but it will be easy to add. I will try to put in 2.4 as well. Thanks, that would be wonderful! -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
Re: [Lcms-user] sRGB with unintended D50 whitepoint
On Sun, Jun 24, 2012 at 2:21 PM, wrote: > Hi Pascal, > >> We've recently discovered that Darktable's (a photography application) >> internal sRGB profile seems to encode a D50 whitepoint even though we >> are passing a D65 whitepoint. The current theory is that this changed >> when we migrated from lcms1 to lcms2. > > Yes, as Kai-Uwe says, this is the expected behavior for a V4 CMM, and > that is what lcms2 is. Please note most if not all modern CMMs behaves > in such way, for example all Adobe products. > > The difference is only in the absolute colorimetric intent. It is > fully described in this paper from ICC: > > http://color.org/ICC_white_paper_6_v2_and_v4_display_profile_differences.pdf > > If anyway, you prefer the old behavior despite that would made your > application inconsistent, you could use cmsSetAdaptationState(0) at > the init time. Ok thanks. >> Also, we noticed lcms2 seems to default to ICCv4: > > Yes, v4 is from 2001 (11 years right now!) Actually most vendors > are using modern versions. Right. >> Is there any way we could stick with ICCv2 (for greater compatibility)? > > Well, lcms2 can read and use v2 profiles, no problem on that. > If you want to save profiles as v2, this is as easy as calling > > cmsSetProfileVersion(hICC, 3.4) > > before saving the profile. On depending on the version number > the tags are saved by using different structures. Thanks. > But again, Kai-Uwe is right. Check the applications you want > to be compatible. Photoshop for example, which is regarded as > the industry standard works in the V4 way. Thanks for clearing this up. We'll probably leave everything as-is (V4) then. Regards, Pascal de Bruijn -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
[Lcms-user] lcms1 and lcms2 sRGB profile XYZ values
Hi,
I have a question about the lcms1 and lcms2 sRGB profiles.
The code for the built-in sRGB profile in cmsvirt.c looks essentially
the same for lcms1 and lcms2. The unadapted xy primaries are
identical:
cmsCIExyYTRIPLE Rec709Primaries = {
{0.6400, 0.3300, 1.0},
{0.3000, 0.6000, 1.0},
{0.1500, 0.0600, 1.0}
};
The lcms1 sRGB profile (http://www.littlecms.com/1/downloads.htm) has
the following RGB XYZ primaries:
0.43607 0.22249 0.01392
0.38515 0.71687 0.09708
0.14307 0.06061 0.71410
For lcms2, is there a difference in the final (built-in) sRGB RGB XYZ
primaries? Or is the lcms2 sRGB profile exactly the same as the lcms1
sRGB profile? I realize that lcms2 now uses V4 by default. But if one
asks for a V2 sRGB profile (is the built-in V2 or V4?), is it the same
profile that was produced by lcms1, at least as far as the XYZ RGB
primaries go?
Elle
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Re: [Lcms-user] sRGB with unintended D50 whitepoint
Hi Pascal, > We've recently discovered that Darktable's (a photography application) > internal sRGB profile seems to encode a D50 whitepoint even though we > are passing a D65 whitepoint. The current theory is that this changed > when we migrated from lcms1 to lcms2. Yes, as Kai-Uwe says, this is the expected behavior for a V4 CMM, and that is what lcms2 is. Please note most if not all modern CMMs behaves in such way, for example all Adobe products. The difference is only in the absolute colorimetric intent. It is fully described in this paper from ICC: http://color.org/ICC_white_paper_6_v2_and_v4_display_profile_differences.pdf If anyway, you prefer the old behavior despite that would made your application inconsistent, you could use cmsSetAdaptationState(0) at the init time. > Also, we noticed lcms2 seems to default to ICCv4: Yes, v4 is from 2001 (11 years right now!) Actually most vendors are using modern versions. > Is there any way we could stick with ICCv2 (for greater compatibility)? Well, lcms2 can read and use v2 profiles, no problem on that. If you want to save profiles as v2, this is as easy as calling cmsSetProfileVersion(hICC, 3.4) before saving the profile. On depending on the version number the tags are saved by using different structures. But again, Kai-Uwe is right. Check the applications you want to be compatible. Photoshop for example, which is regarded as the industry standard works in the V4 way. Best regards Marti -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
Re: [Lcms-user] defining TYPE_ABGR_FLT
Hi, >> >> Lcms2 error: 8 Unsupported raster format Yes, this is not supported in 2.3, but it will be easy to add. I will try to put in 2.4 as well. Regards Marti Boudewijn Rempt escribió: > On Wednesday 20 June 2012 Jun, Kai-Uwe Behrmann wrote: >> Am 18.06.12, 15:13 +0200 schrieb Boudewijn Rempt: >> > Er, what I want to define is of course BGRA, not ABGR. >> > >> > On Mon, 18 Jun 2012, Boudewijn Rempt wrote: >> >> #define TYPE_ABGR_FLT >> >> >> (FLOAT_SH(1)|COLORSPACE_SH(PT_RGB)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(4)|DOSWAP_SH(1)|SWAPFIRST_SH(1)) >> >> >> >> But when I try to use that in a conversion, I get an lcms error: >> >> >> >> Lcms2 error: 8 Unsupported raster format >> >> TYPE_BGRA_FLT should be defined as: >> (FLOAT_SH(1)|COLORSPACE_SH(PT_RGB)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(4)|DOSWAP_SH(1)) >> >> Otherwise that definition follows the other lcms colour spaces. >> > > Well, I looked at > > #define TYPE_BGRA_8 > (COLORSPACE_SH(PT_RGB)|EXTRA_SH(1)|CHANNELS_SH(3)|BYTES_SH(1)|DOSWAP_SH(1)|SWAPFIRST_SH(1)) > > so I added the extra SWAPFIRST_SH(1), it' the difference between > bgra and abgr. >> > > > -- > Boudewijn Rempt > http://www.valdyas.org, http://www.krita.org, http://www.boudewijnrempt.nl > > -- > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > ___ > Lcms-user mailing list > Lcms-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/lcms-user > -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
Re: [Lcms-user] sRGB with unintended D50 whitepoint
Am 23.06.12, 20:51 +0200 schrieb Pascal de Bruijn: > We've recently discovered that Darktable's (a photography application) > internal sRGB profile seems to encode a D50 whitepoint even though we > are passing a D65 whitepoint. The current theory is that this changed > when we migrated from lcms1 to lcms2. The whitepoint goes into the chromatic adaptation tag. D50 is defined for v4 profiles in the spec. Look for some examples on the official ICC website: http://www.color.org/srgbprofiles.xalter > Is there any way we could stick with ICCv2 (for greater compatibility)? The compatibility argument applies to what specific CMM? Most CMMs support v4 profiles after all these years. Picking a on disc ICC profile is no option for darktable? kind regards Kai-Uwe -- Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ ___ Lcms-user mailing list Lcms-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/lcms-user
