Digital test form for ICC-profiles
2005 (English)In: TAGA 2005, 2005, 454-473 p.Conference paper (Refereed)
The majority of Swedish offset printers use color management in order to control color reproduction in their daily production. However, there is a lack of understanding of how well the profiles support agreement among color units. Several parameters in the construction and use of a profile affect the final color result. Print production using ICC-profiles demands a better teamwork in the process. The use of non-dedicated printer profiles may cause a less than optimal end-result. Pedagogic color tools can help the user to understand how well a specific profile defines the color gamut of a digital/analogue printingpress. This paper presents an approach to visualizing how well printer profile parameters are defined in the construction of the ICC-profile. The application Adobe Photoshop ® has been used for profile evaluation because of its widespread use in the graphic arts field. A digital test form has been produced consisting of color test targets and images. This digital test form can give information about: 1) differences between color gamuts, e.g. ECl-RGB, ColorMatch 2) total ink coverage 3) the level of achromatic reproduction, GCR, UCR (Gray Component Replacement, Under Color Removal) 4) effect on different tones, e.g. skin tones 5) comparison between different print profiles and the ISO standard - gamut warning 6) gamut mapping 7) different rendering methods 8) chroma shift when converting to CMYK 9) control of gray balance 10) control of color settings in the applications - ProfileMaker and Print Open The basic model is made from a number of color patches forming a uniform matrix pattern. The matrix construction was created in Adobe Illustrator and Adobe Photoshop. The testform is built in the RGB-color mode, using the standardized color working space, ECI-RGB. To achieve an even distribution of lightness and saturation in the matrix, the HSB (Hue, Saturation and Brightness) color model was chosen. Moving from one patch to the next represents a change in saturation and lightness by ten percent. The colors red and cyan, green and magenta, blue and yellow are confronted to each other as a result of their relationship as complement colors. The center point of the model holds a gray scale built from equal amounts of red, green and blue parts in the RGB-mode. The base model contains information about the total ink coverage (%) and control of color cast. Each matrix has been complemented with a color wise corresponding image to enhance the color conversion change. These images have also been divided into a mosaic pattern to enable measurements directly on the images. This digital test form for ICC-profiles has been evaluated by eight independent graphic arts consultants who work with the implementation of ICC-based production. The result of this evaluation is a recommendation for the printers to use this digital test form to increase awareness of the influence of ICC-profiles on the print.
Place, publisher, year, edition, pages
2005. 454-473 p.
Communication; Conversion; Education; ICC; Separation
IdentifiersURN: urn:nbn:se:kth:diva-6574OAI: oai:DiVA.org:kth-6574DiVA: diva2:11322