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The standardized residual sum of squares (STRESS) index was used to reevaluate four experimental datasets employed during the development of CIEDE2000, the current CIE recommended color-difference formula. This index enables statistical inferences not achievable by other metrics used commonly for performance evaluation. It was found that CIEDE2000 was(More)
Using simulated data sets, we have analyzed some mathematical properties of different statistical measurements that have been employed in previous literature to test the performance of different color-difference formulas. Specifically, the properties of the combined index PF/3 (performance factor obtained as average of three terms), widely employed in(More)
Threshold-discrimination ellipses were obtained by three normal observers, at five color centers, by the use of two experimental devices, which provided light-surface colors, and the same method and experimental conditions. The ellipses obtained for each center in both devices were quite similar when the sample distributions were appropriate and slightly(More)
This work continues previous research by the same authors [J. Opt. Soc. Am. A23, 2077 (2006)], where empirical small-medium color differences were represented by an ellipsoidal equation DeltaEGP in the Uniform Color System of the Optical Society of America. Now logarithmic compressions on chroma and lightness are introduced to produce a new space with(More)
The CMC, BFD, and CIE94 color-difference formulas have been compared throughout their weighting functions to the CIELAB components ⌬L*, ⌬C*, ⌬H*, and from their performance with respect to several wide data-sets from old and recent literature. Predicting the magnitude of perceived color differences, a statistically significant improvement upon CIELAB should(More)
We propose a new approach to the quantitative determination of the iris colour through the spectroradiometric measurement of a set of 72 artificial irises under controlled illumination and geometry. The spread of these samples in the CIELAB colour space indicates no clearly distinguished groups within the set analysed. Colour measurements for different(More)
CIELAB-based color-difference formulas are used to improve the prediction of visually perceived color differences through the introduction of various corrections to CIELAB. In our study we analyze the relative importance of these corrections. From the combined dataset employed for the development of CIEDE2000, we found that the improvement of CIE94 over(More)
The CIELAB lightness and chroma values of pixels in five of the eight ISO SCID natural images were modified to produce sample images. Pairs of images were displayed on a calibrated monitor and assessed by a panel of 12 observers with normal color vision using a categorical judgment method. The experimental results showed that assuming the lightness(More)
The RIT–DuPont visual color-difference data as the RIT–DuPont data set, and they are the basis for [Color Res. Appl. 16, 297–316 (1991)] have been used our current analyses. to estimate contours of equal color-differences (ellip-The RIT–DuPont data set consists of 156 tolerances, soids) at 19 color centers, in CIELAB and x, y, Y/100 each of equal visual(More)