@article{shamey_lin_sawatwarakul_cao_2014, title={Evaluation of Performance of Various Color-Difference Formulae Using an Experimental Black Dataset}, volume={39}, ISSN={["1520-6378"]}, DOI={10.1002/col.21844}, abstractNote={The objective of this study was to develop a specific visual dataset comprising black-appearing samples with low lightness (L* ranging from approximately 10.4 to 19.5), varying in hue and chroma, evaluating their visual differences against a reference sample, and testing the performance of major color difference formulas currently in use as well as OSA-UCS-based models and more recent CAM02 color difference formulas including CAM02-SCD and CAM02-UCS models. The dataset comprised 50 dyed black fabric samples of similar structure, and a standard (L*= 15.33, a* = 0.14, b* = −0.82), with a distribution of small color differences, in ΔE*ab, from 0 to approximately 5. The visual color difference between each sample and the standard was assessed by 19 observers in three separate sittings with an interval of at least 24 hours between trials using an AATCC standard gray scale for color change, and a total of 2850 assessments were obtained. A third-degree polynomial equation was used to convert gray scale ratings to visual differences. The Standard Residual Sum of Squares index (STRESS) and Pearson's correlation coefficient (r), were used to evaluate the performance of various color difference formulae based on visual results. According to the analysis of STRESS index and correlation coefficient results CAM02 color difference equations exhibited the best agreement against visual data with statistically significant improvement over other models tested. The CIEDE2000 (1:1:1) equation also showed good performance in this region of the color space. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 589–598, 2014}, number={6}, journal={COLOR RESEARCH AND APPLICATION}, author={Shamey, Renzo and Lin, Juan and Sawatwarakul, Weethima and Cao, Renbo}, year={2014}, month={Dec}, pages={589–598} } @article{shamey_cao_tomasino_zaidy_iqbal_lin_lee_2014, title={Performance of select color-difference formulas in the blue region}, volume={31}, ISSN={["1520-8532"]}, DOI={10.1364/josaa.31.001328}, abstractNote={The main objective of this work was to test the performance of major formulas for assessment of small suprathreshold color differences in the blue region. The models examined include CIELAB color space based equations, including CIELAB, CIE94, CIEDE2000, CMC (l:c), BFD (l:c), and formulas based on more uniform color spaces, such as DIN99d, CAM02-SCD, CAM02-UCS, OSA-GP, and OSA-Eu in comparison against data obtained via visual assessments. For this purpose, a dataset around the CIE high-chroma blue color center, hereafter called NCSU-B2, was developed. The NCSU-B2 dataset comprised 65 textile substrates and a standard, with a mean ΔE(ab)* color difference of 2.72, ranging from 0.54-5.72. Samples were visually assessed by 26 subjects against the reference gray scale in three separate trials with at least 24 h between assessments. A total of 5070 assessments were obtained. The standardized residual sum of squares (STRESS) index was used to examine the performance of various formulas for this dataset, as well as a previously developed NCSU-B1 low-chroma blue dataset [Color Res. Appl. 36, 27, 2011], and blue centers from other established visual datasets. Results show that formulas based on more recent uniform color spaces provide better agreement with perceptual data compared with models based on CIELAB space.}, number={6}, journal={JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION}, author={Shamey, R. and Cao, R. and Tomasino, T. and Zaidy, S. S. H. and Iqbal, K. and Lin, J. and Lee, S. G.}, year={2014}, month={Jun}, pages={1328–1336} } @article{lin_shamey_hinks_2012, title={Factors affecting the whiteness of optically brightened material}, volume={29}, ISSN={["1520-8532"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84869782509&partnerID=MN8TOARS}, DOI={10.1364/josaa.29.002289}, abstractNote={The whiteness of fluorescent white materials is in part due to the absorption of ultraviolet (UV) light and subsequent emission of visible blue light. The UV content of light sources in viewing booths and in spectrophotometers can thus significantly affect the perceived whiteness (PW) and measured sum of reflected and emitted light of fluorescent materials. The effect of UV content on the spectral radiance factor of fluorescent white materials containing different amounts of a fluorescent brightening agent and the subsequent assessment of their PW were evaluated. The UV content of sources in two calibrated viewing booths that simulated D65 and D75 illuminants, separately, was changed by selectively blocking UV emission of the source by approximately 0%, 25%, 50%, 75%, and 100%. The radiance spectra of a series of white fabrics were also obtained using a reflectance spectrophotometer at 0%, 25%, 50%, 75%, and 100% UV transmittance. The CIE and Uchida whiteness indices (WIs) were calculated for white samples and compared to perceptual results under varying illumination and UV conditions. Results indicate relatively modest agreement between perceptual assessments of fluorescent samples and whiteness metrics examined. Results also show that when the UV content of sources used in the viewing booths is adjusted to be similar to that used in measurements, improved correlations between perceptual and calculated results are obtained. The CIE WI was found to outperform the Uchida index under both sources.}, number={11}, journal={JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION}, author={Lin, Juan and Shamey, Renzo and Hinks, David}, year={2012}, month={Nov}, pages={2289–2299} } @article{lin_shamey_trussell_2012, title={The effect of texture on perception and measurement of whiteness}, volume={12}, number={2}, journal={AATCC Review}, author={Lin, J. and Shamey, R. and Trussell, J.}, year={2012}, pages={61–68} }