Hi, Unfortunately, both conversions Lab <-> XYZ and XYZ <-> sRGB are non linear. XYZ <->sRGB goes across approximate 2.2 exponential curves, and XYZ<->Lab is far more complex.
So, no, there is no way to convert between those colorspaces using any matrix. You can find additional information on sRGB math here: http://www.srgb.com/basicsofsrgb.htm and XYZ->Lab is defined as: L* = 116*f(Y/Yn) - 16 0 <= L* <= 100 a* = 500*[f(X/Xn) - f(Y/Yn)] b* = 200*[f(Y/Yn) - f(Z/Zn)] and f(t) = t^(1/3) 1 >= t > 0.008856 7.787*t + (16/116) 0 <= t <= 0.008856 Regards, Marti Maria The little cms project http://www.littlecms.com [EMAIL PROTECTED] ----- Original Message ----- From: "Kai-Uwe Behrmann" <[EMAIL PROTECTED]> To: "Lcms Liste" <[EMAIL PROTECTED]> Sent: Thursday, February 05, 2004 11:08 AM Subject: [Lcms-user] standard matrices Hi, I like to do optimized standard transformations outside lcms. Are the conversions between PCS XYZ <-> Lab and from PCS <-> sRGB matrix based? So it would be simple to do the math in the application. Is this approach possible? If yes, where can I find these matrixes? Are they publically available? regards Kai-Uwe ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user
