Hello,

I try doing the Lab to CMYK convertion with snippet like below, it works

    double fLab[3];
    unsigned char nCMYK[4];

    fLab[0] = 50.0;
    fLab[1] = 80.0;
    fLab[2] = 50.0;
    hOutProfile = cmsOpenProfileFromFile(szPath, "r");
    hLabProfile = cmsCreateLabProfile(NULL);
    hTransform = cmsCreateTransform(hLabProfile,
                                 TYPE_Lab_DBL,
                                 hOutProfile,
                                 TYPE_CMYK_8,
                                 intent, 0);

    cmsDoTransform(hTransform, fLab, nCMYK, 1);
    cmsDeleteTransform(hTransform);
    cmsCloseProfile(hLabProfile);
    cmsCloseProfile(hOutProfile);

But when I change it to Lab 8 bit, it does not produce the similar result.

    unsigned char nCMYK[4];
    unsigned char nLab[3];

    nLab[0] = 50;
    nLab[1] = 80;
    nLab[2] = 50;
    hOutProfile = cmsOpenProfileFromFile(szPath, "r");
    hLabProfile = cmsCreateLabProfile(NULL);
    hTransform = cmsCreateTransform(hLabProfile,
                                 TYPE_Lab_8,
                                 hOutProfile,
                                 TYPE_CMYK_8,
                                 intent, 0);

    cmsDoTransform(hTransform, nLab, nCMYK, 1);
    cmsDeleteTransform(hTransform);
    cmsCloseProfile(hLabProfile);
    cmsCloseProfile(hOutProfile);

Is it because Lab values are different for 8 bit format & double format ?

The range is something like this ?
L = 0 to 100
a = -127 to 127
b = -127 to 127

Thanks.

Peter



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