Hi Marti,
thank you for aid, it was a range problem.

I'm new to lcms and color management so apologize my tedious questions.

I took a look to documentation and I cannot find info about color ranges. I know CIE defines Y value in range 0..100
so why sometimes is used the range 0..1.0? In lcms the range 0..1.0 is also used for other color standard? (e.g. CIE Lab?)


Regards,
Andrea

Marti Maria wrote:

Hi,

It works to me... you can try icctrans utility that does the same:

First I try a blue tone that is outside SWOP gamut, then a gray that is inside. icctrans is marking out of gamut as (255, 255,255)

F:\lcms>icctrans -t1 -i*XYZ -o*sRGB -g -p USWebCoatedSWOP.icc
little cms ColorSpace conversion calculator - v1.8

Enter values, 'q' to quit
X? 0.124
Y? 0.528
Z? 0.622

R=255.00 G=255.00 B=255.00

Enter values, 'q' to quit
X? 0.21
Y? 0.22
Z? 0.18

R=129.09 G=129.81 B=128.27

Enter values, 'q' to quit
X? q
Done.

Maybe you are using XYZ values on 0..100 range? Try to normalize them
to 0..1.0, that is, divide XYZ values by 100. It should work.


Besides, there are many improvements on gamut cheking in 1.14, so
I would recommend to try the last version.

Regards,
Marti Maria
The little cms project
http://www.littlecms.com


----- Original Message ----- From: "Andrea Galligani" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, December 17, 2004 11:24 AM
Subject: [Lcms-user] out-of-gamut condition





Hi,

I need to check the out-of-gamut condition of several XYZ points in a generic profile.
I tried the following code:


   hInProfile  = cmsCreateXYZProfile();
   hOutProfile = cmsCreate_sRGBProfile();
   hProofProfile = cmsOpenProfileFromFile( m_ProfileName, "r");

hColorTrans = cmsCreateProofingTransform( hInProfile, TYPE_XYZ_DBL,
hOutProfile, TYPE_RGB_8,
hProofProfile,
INTENT_PERCEPTUAL,
INTENT_ABSOLUTE_COLORIMETRIC,
cmsFLAGS_GAMUTCHECK | cmsFLAGS_SOFTPROOFING );
cmsSetAlarmCodes( 0, 0, 0 );


but any XYZ point translated using
   cmsDoTransform( hColorTrans, XYZarray, RGBarray, nPoints );

produces an out-of-gamut condition (a (0, 0, 0) RGB value)

I tried several profiles, including the standard sRGB, obtaining the same result.

Probably I do something wrong but I don't know where.

Can somebody help me?
Thank you in advance.

Andrea

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