Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, s/n 18071, Granada, Spain.
Department of Computer Architecture and Computer Technology, E.T.S.I.I.T., University of Granada, s/n 18071, Granada, Spain.
J Dent. 2024 Nov;150:105327. doi: 10.1016/j.jdent.2024.105327. Epub 2024 Aug 26.
To evaluate the perceptibility and acceptability CIEDE2000 (K:K:K) thresholds for lightness, chroma and hue differences in dentistry.
A Python-based program was developed to conduct a psychophysical experiment based on visual assessments of computer-simulated images of human teeth. The experiment was performed on a calibrated display. A 40-observer panel: dentists and laypersons (male and female; n=10), evalu- ated three subsets of simulated human teeth: the lightness subset (%∆L ≥ 98 %), the chroma subset (%∆C ≥ 98 %) and the hue subset (%∆H ≥ 98 %), using ∆E ≥ 5 units. A Takagi-Sugeno-Kang Fuzzy Approximation model was used as fitting procedure, and 50:50 % lightness, chroma and hue CIEDE2000 (1:1:1) and CIEDE2000 (2:1:1) perceptibility (PT) and accept- ability (AT) thresholds were calculated. Data was statistically analyzed using t-test (p < 0.05).
The 50:50 % PT for K=1 were ∆L=1.04, ∆C=1.58 and ∆E=1.01; and for K=2 were ∆L=0.51, ∆C=1.58 and ∆E=0.71. The 50:50 % AT for K=1 were ∆L=2.82, ∆C=3.04 and ∆E=2.66; and for K=2 were ∆L=1.40, ∆C=3.04 and ∆E=1.78. PT and AT ∆H may be considered no computable. A significant difference was found between CIEDE2000(1:1:1) and CIEDE2000(2:1:1), between lightness and chroma metrics, and between observer groups. No differences for lightness and chroma PT were found between male and female groups.
It is important to use PT and AT for lightness, chroma and hue specific to evaluate perceptual sensitivity for color changes in the tooth color space. AT for lightness and chroma are influenced by the observer's experience and gender. Males and laypersons show more tolerance for changes in chroma (∆C) and in lightness (∆L).
Hue and chroma mismatch are more difficult to be accepted in dental color space.
评估在牙科中使用 CIEDE2000（K:K:K）色差感知和可接受性阈值来测量明度、彩度和色调差异的效果。
使用基于 Python 的程序，基于计算机模拟的人类牙齿图像的视觉评估，进行心理物理实验。实验在经过校准的显示器上进行。一个由 40 名观察者组成的小组（牙医和非专业人士，男女各 10 人）评估了三个模拟人类牙齿子集：明度子集（%∆L≥98%）、彩度子集（%∆C≥98%）和色调子集（%∆H≥98%），使用 ∆E≥5 个单位。使用 Takagi-Sugeno-Kang 模糊逼近模型作为拟合过程，并计算了 50:50%明度、彩度和色调 CIEDE2000（1:1:1）和 CIEDE2000（2:1:1）感知（PT）和可接受性（AT）阈值。使用 t 检验（p<0.05）对数据进行统计学分析。
K=1 的 50:50%PT 为 ∆L=1.04、∆C=1.58 和 ∆E=1.01；K=2 的 50:50%PT 为 ∆L=0.51、∆C=1.58 和 ∆E=0.71。K=1 的 50:50%AT 为 ∆L=2.82、∆C=3.04 和 ∆E=2.66；K=2 的 50:50%AT 为 ∆L=1.40、∆C=3.04 和 ∆E=1.78。PT 和 AT ∆H 可能无法计算。CIEDE2000（1:1:1）和 CIEDE2000（2:1:1）之间、明度和彩度度量之间以及观察者群体之间存在显著差异。男性和女性群体之间在明度和彩度 PT 方面没有发现差异。
在评估牙齿颜色空间中颜色变化的感知敏感性时，使用明度、彩度和色调特定的 PT 和 AT 非常重要。明度和彩度的 AT 受观察者经验和性别影响。男性和非专业人士对彩度（∆C）和明度（∆L）的变化表现出更高的容忍度。
在牙科颜色空间中，色调和彩度不匹配更难被接受。
