Workshop on colorimetry, graphic arts and colour management
Colour management is concerned with matching colour values across different media, and to do this unambiguously it is important to base colour data encodings and the ICC Profile Connection Space on well-defined colorimetry.
CIE is holding a Workshop on Colorimetry and Graphic Arts to enable issues around CIE colorimetry that could affect communication of colour information in graphic arts colour reproduction to be discussed. This will take place at University of Leeds, UK on July 4 2013.
CIE Division One has a number of Technical Committees working on topics of interest to the colour management and graphic arts communities. ICC supports the initiative of CIE Division 1 to actively address such topics.
Topics
Topics to be discussed at the workshop include:
- Colour difference metrics
- Illuminants and colour rendering
- Surface of real colour gamuts
- Modifications to CIECAM02 colour appearance model
ISO Technical Committee 130 Graphic Technology has identified a number of issues through its regular liaison with both CIE and ICC. These issues include:
CIEDE2000
CIE has recommended the advanced colour difference formula CIEDE2000 for expressing small differences between samples. Many implementers have found the published documentation of this formula to be too complex to be able to implement unambiguously, and TC 130 would like to have more guidance and clarification on this.
Over-range L* values
CIE Publication 15:2004 defines the range of L* as 0 to 100. In practice it is possible to encounter L* values higher than 100, for example in the case of fluorescent samples under UV-rich illumination. The ICC specification enables Y values greater than 100 to be encoded, and TC 130 would like guidance on how such values should be converted to CIELAB L*.
Colour rendering of white light sources
Light sources for viewing surface colours are evaluated by a Color Rendering Index (CRI). ISO TC 130 references CRI calculations in its standards for measurement and viewing, but newer types of illumination now being used, especially LEDs, have created the need to re-define the CRI calculation.
Colour difference in neutrals
In image reproduction, getting neutral (grey) correct, at all lightness levels, is considered to be of critical importantance. Current colour difference metrics, including CIEDE2000, do not allow users to define how different two grays can be and still be perceived as equivalent.
Call for participation
If you are interested in participating in this Symposium, please contact the ICC Technical Secretary. If you wish to present a paper on any of the topics above, send a title and short abstract.