Hello,
I've tried to find out the answer to this question in tutorial,
samples sources and in the mailing list, but failed to achieve the
required results.
So, I have lots of TIFF files created on Macs with Adobe Photoshop.
Some of them are in sRGB; most of them are in AdobeRGB. All of them
have the corresponding ICC profiles embedded inside.
So, I need to convert them to linear color space, basically, by going
from sRGB (approx. gamma 2.2, but the exact algorithm is slightly
different) and AdobeRGB (also almost 2.2). Previously I've been
working with sRGB only and used some custom math, but now we're
switching to AdobeRGB and I don't want to touch the math anymore, so I
want to switch to LCMS for conversion.
The problem is - how do I create the linear gamma 1.0 profile and
corresponding transform?
LPGAMMATABLE Transfer[3];
cmsHPROFILE LinearProfile;
Transfer[0] = cmsBuildGamma(256, 1);
Transfer[1] = cmsBuildGamma(256, 1);
Transfer[2] = cmsBuildGamma(256, 1);
LinearProfile = cmsCreateLinearizationDeviceLink(icSigRgbData,
Transfer);
doesn't work:
int iccfound = 0;
iccfound = TIFFGetField(in, TIFFTAG_ICCPROFILE, &profile_size,
&icc_profile);
if (iccfound) {
TiffProfile = cmsOpenProfileFromMem(icc_profile, profile_size);
}
and then
DWORD PixelType = TYPE_RGBA_16;
hTransform = cmsCreateTransform(TiffProfile,
PixelType,
LinearProfile,
PixelType,
INTENT_PERCEPTUAL, 0);
results in error 12288: invalid PCS. And I still think it shouldn't,
since it's not real profile per se.
So what's the basic idea? How can I create the linear profile without
reverting to some ICC files I have no idea where to get from?
Sorry if the question is dumb, but I'm really out of ideas.
Alexei Puzikov
-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Lcms-user mailing list
Lcms-user@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/lcms-user
