Hi Gerhard, I'm CC also to the mailing list, since this could be interesting.
>In which practical situations would it actually be useful to apply this >"cmsCreateInkLimitingDeviceLink" transform? The ink limiting applies basically to different *media* Let's take following case example. You have profiled your printer for a given paper, say semigloss. This works great, and the colorimetry is almost exact (rare case, indeed). Then you need to print in another media, say glossy. And the paper doesn't accept such quantity of ink and the excessive CMY causes muddy tones or worst, the ink begins to spread over the paper. In such situation you need something that simply limits the quantity of total ink but keeps the proportion of CMY and keeps K ink untouched. This is exactly what is doing ink limiting. In practical cases works reasonably well. There is a small loss of precission, but the overall benefits are way better. Yes, of course, the best solution would be to embed the ink limiting into BtoA of output profile, and then use a different profile for each media, but this is not always possible. So, a ink limiting plus a linearization (see cmsCreateLinearizationDevicelink) can effectively accomodate a yet existing profile to different media. And this is the function of these virtual profiles. Regards, Marti Maria The little cms project http://www.littlecms.com [EMAIL PROTECTED] ----- Original Message ----- From: "Gerhard Fuernkranz" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, July 11, 2003 12:23 AM Subject: Re: [Lcms-user] Lot of questions! ;) Marti Maria schrieb: >Latest version of lcms has a way to introduce >ink limiting by using a hypercube algorithm. > Hi Marti, I've found a single API function "cmsCreateInkLimitingDeviceLink" for ink limiting. However, it performs a transform in device CMYK space only. So I guess this tansform cannot guarantee that the output colors will have any specific _colorimetric_ relation to the input colors, like preservation of the color, if an input color which exceeds the ink limit could also be represented by a different CMYK combination which does not exceed the limit (e.g. by reducing C, M and Y and adding more black), or preservation of hue and/or lightnes if the ink limit constraint makes gamut remapping unavoidable. In which practical situations would it actually be useful to apply this "cmsCreateInkLimitingDeviceLink" transform? The BtoA tables of CMYK profiles are basically expected to perform the required ink limiting for the device anyway, aren't they? So isn't ink limiting much more interesting in conjunction with "profile inversion" (i.e. BtoA table generation) than as a standalone function which works in CMYK device space only? Thanks, Gerhard ------------------------------------------------------- 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/bulletproofapps1 _______________________________________________ Lcms-user mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/lcms-user
