Details:
Summary:
A study has been made of color difference data from four laboratories. This was done to test a number of standard color difference formulas along with a new color channel model for performances against the known data. This study shows that the current CIEDE2000 has large systematic errors and is not an improvement on the CIEDE94 metric. It also illustrates that a simple color channel model performs as well as the more complex CIE color difference formulas. A simple color channel model has been developed based on the ATD color opponent color space first proposed by Lee Guth (1973). The new model is non Euclidean and is based on the actions of the opponent channels of human vision. The ATD model has been simplified by Granger (2001) to yield a uniform chromaticity space that has been specifically tuned to Graphic Arts applications. The ATD model is expanded in this report to include a color difference formula, Delta Perception (DP), for the perceived subjective color difference. The accuracy of the new color difference formula is compared with DE2000, DIN99, DE94, CMC (1, 1) and DE76. The result of the study shows that a simple three term formula gives good performance compared to the extant color difference formulas. A secondary discovery was that new color difference formula produces nearly identical error distributions. The other color difference equations produce error distributions with differing means. This indicates that there is a bias built into the each model that does not offer equal treatment to all the test data.