Details:
Summary:
Optimized image reproduction is becoming more critical as parallel publication is gaining field. The print buyers' and end users' demands for quality are also increasing. By using a common format (ICC) for characterization of color units it is easier to determine the color gamut of a device and thereby optimize a printout. The characterization of a color unit is achieved by printing and measuring target values in a color chart. There are a number of different color charts on the market, all with one thing in common; they are assumed to be valid for all types of images, no matter if the relevant image information is located in hikey areas, low-key areas or in the mid-tones. The effect of this is that too few color tones containing key image information can be analyzed.
To correct for this, new adapted color charts have been created based on technical and visual image category analyses. A number of tests have been carried out using extreme images with their key information strictly in dark and light areas. Preliminary results show that the image categorization using the adapted color charts improves the analysis of relevant image information with regard to both the image gradation and the detail reproduction. The new adapted color charts preserve details in the low-key areas, producing a more distinct image with a better agreement with the original. Evaluations have been made using a test panel and the pair-by-pair comparison method.
Images with the key information in hi-key areas were also test printed using the adapted color charts. The results here show no significant enhancement in image quality. However, images with the core information in the mid-tone regions show an improvement in reproduction compared to the original. The tests show that an improved image reproduction can be obtained by adapting the ICC profiles used to the specific image types to be printed.