Hi, > Is Linear Bradford the default ICC method for monitor (scanner) profiling?
Yes, as stated in ICC 4.0 spec. This is a simplification of Bradford transform. Most profilers works in such way (sRGB standard profile and Adobe gamma, for example) It works reasonably well. However, the state-of-the-art actually is other CAT called CAT02, but don't worry, next version will support that one and the differences are really minimal. > Is Linear Bradford also a CAM (Bradford-Hunt 96s) but we don't have >the option to change parameters for surround influence? Is just a CAT (Chromatic adaptation). It models the white point translation. A full CAM in the other hand models viewing conditions too. CAT is only a part of CAM. >- Is "normal" monitor profile "Phisical model" as described in >Fairchilds book? The monitor lprof profiler uses a CRT gamma-gain-offset model. Works great for CRT monitors but no so well for LCD and TFT. On those cases, you should use the advanced mode, with a spider for taking monitor measurements. >- Is PCS different between "normal" and CAM method for profiling (I >supose not)? In lprof profiler yes, I do use Lab for CIECAM97s and XYZ for quick and dirty. But this is not so important, is just a way to encode data, since the real pixels would never be converted to Lab or XYZ by the CMM. >- Does anyone knows what are options in PM4.1 (printer profiling) black >generation, GCR, UCR, ink limiting ... Here I cannot help since I don't know PM4, but ... GCR: Grey color replacement. Has to do with black generation and is one of the most difficult things in making CMYK profiles. GCR algorithms are often proprietary. Part of the "secret sauce" of profilers. UCR: Under color removal. Is part of GCR. It handles when C,M,Y ink has to be removed because black ink already gives the necessary dark tone. Ink limiting: This is an algorithm to remove the excessive amount of C,M,Y ink and keep K for a given paper (media). Latest version of lcms has a way to introduce ink limiting by using a hypercube algorithm. The profile can contain ink limiting, too. Regarding ICC spec, well, you could read if want so, but is highly technical about internals of profiles. I was going to recommend you the Fairchild book, but you have already read it :-) Regards, Marti Maria The little cms project http://www.littlecms.com [EMAIL PROTECTED] ----- Original Message ----- From: "Andrej Javorsek" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, July 10, 2003 3:47 PM Subject: [Lcms-user] Lot of questions! ;) Hello! Hope that someone coluld find time to answer some beginer questions. I'm allready using color management in its many variations (scanner, printer, monitor, digital camera). For profiling purposes I use GretagMacbeth ProfileMaker 3.1 and 4.1 (PM) and sometimes Lprof. And now for the questions part. ;) I don't know wht kind of method is used in PM but I can see that Lprof has option of using Linear Bradford - Matrix/Shaper and CIECAM97s method for profiling. I've read M. Farchilds book Color Apearance Models, so I supose I understand CIECAM97s method but i don't know what is Linear Bradford. - Is Linear Bradford the default ICC method for monitor (scanner) profiling? - Is Linear Bradford also a CAM (Bradford-Hunt 96s) but we don't have the option to change parameters for surround influence? - Is "normal" monitor profile "Phisical model" as described in Fairchilds book? - Is PCS different between "normal" and CAM method for profiling (I supose not)? - Does anyone knows what are options in PM4.1 (printer profiling) black generation, GCR, UCR, ink limiting ... Is it posibe to actualy control those options thru profile or is there any other reason? Maybe instead of exact answering on my questions, you can just ponit on proper papers (preferable chapters in papers) where can I get the answers (BTW: I have ICC specification but I haven't read it yet besause of lack of time). Regards! Andrej Javorsek ------------------------------------------------------- This SF.Net email sponsored by: Parasoft Error proof Web apps, automate testing & more. Download & eval WebKing and get a free book. www.parasoft.com/bulletproofapps _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user ------------------------------------------------------- This SF.Net email sponsored by: Parasoft Error proof Web apps, automate testing & more. Download & eval WebKing and get a free book. www.parasoft.com/bulletproofapps _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user
