Scarse Profile Library Warning

Scarse is a project for profiling scanners under GPL based on Argyll code. It started in the old century and became pretty silent, with the last news dating from 2005. The project provides a nice collection of ICC profiles in the Scarse Profile Library, which is now used by some open source graphics packages. ICC profiles referring to standards are used to describe the exact colorimetry of a colour space. The ICC profiles are used to convert to and from other colour spaces in order to exchange with applications, services and customers. It is therefore crucial to meet these standards otherwise results will be incorrect right from the beginning and might render further colour work damaged.

Claudio Wilmanns revealed today a colorimetric imprecision inside the Scarse WideGamutRGB profile. Norman Koren hinted that the Scarse profiles do not pass a profile validation tool. OpenICC could never verify these profiles or how they where build and therefore did not cover any of them in its icc-profiles-openicc data set.

After these comments I like to warn of the usage and distribution of any of the Scarse Profiles for the sake of users trusting profiles of the affected packages in their workflows. We are looking for replacements for some of the most popular ones.

Affected Profiles are AdobeRGB, AppleRGB, WideGamutRGB, CIE-RGB, ECI-RGB, sRGB, KodakProPhotoRGB, ColorMatchRGB and more.

Affected Packages are libkdcraw. Some of the shared-color-profiles/Argyll ‘lcms’ generated profiles from the colord author use in parts the colorimetry of Scarse profiles. The later profiles are not included in the Argyll-1.1.0 source package. These profiles are at risk.

Disclaimer: the author, Kai-Uwe Behrmann, maintains the icc-profiles-openicc package containing ICC profiles describing colour standards.

3 thoughts on “Scarse Profile Library Warning

  1. Since the originals are usually inappropriately licensed, shipping Free cleanroom implementations which will necessarily be approximations is the only legal option we have. So I’d tend towards declaring this NOTABUG. (OTOH, if files with those non-Free licenses are being shipped, I’d very much like to see THAT fixed ASAP, even if it means replacing them with less accurate files. Being Free is more important than being accurate to the bit.)

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