Do specular highlights and the daylight locus act as cues for estimating illumination color from a single object?
Do specular highlights and the daylight locus act as cues for estimating illumination color from a single object?
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镜面高光和日光轨迹是否可以作为估计单个物体的照明颜色的线索？
DOI：
10.1007/s10043-016-0295-6
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发表时间：
2017
期刊：
影响因子：
1.2
通讯作者：
Yasuki Yamauchi
中科院分区：
文献类型：
--
作者：
Takehiro Nagai;Shigeyuki Kaneko;Yuki Kawashima;Yasuki Yamauchi
对象曲面上的镜面反射高光可以用作估计照明颜色的线索，因为许多对象上的高光直接反映照明颜色。此外，我们的经验，照明颜色通常有色度附近的日光轨迹在日常生活中，这种经验可能会影响我们的照明颜色的估计。在这项研究中，我们研究了镜面高光和物体颜色的影响，人类观察者使用一个单一的物体与镜面高光作为刺激的图像的照明颜色的估计。在实验中，具有镜面高光的对象上的所有像素的颜色在试验中从参考D65色度改变为测试色度。观察者判断这种色度变化似乎是由改变物体或改变照明引起的。在控制实验中，观察者执行相同的任务的刺激垫对象没有镜面高光。使用不同的色调和饱和度值作为测试色度。结果表明，当测试色的饱和度较低时，色度变化更可能是由改变光照引起的。此外，“照明改变”的反应的比率略高于镜面高光的对象比没有镜面高光的对象。然而，在观察者之间平均的“照明改变”响应的比率在颜色方向上没有很大的不同。这些结果表明，镜面高光略有贡献的照明颜色的估计，和日光轨迹并没有很大程度上影响照明颜色的估计。
Specular highlights on the surface of an object can serve as cues for estimating illumination color, because highlights on many objects directly reflect illumination colors. In addition, we experience that illumination colors typically have chromaticities near the daylight locus in daily life, and this experience may possibly affect our estimation of the illumination color. In this study, we investigated the effects of specular highlights and object colors on the estimation of the illumination colors by human observers using images of a single object with specular highlights as stimuli. In the experiments, the colors of all pixels on an object with specular highlights changed from the reference D65 chromaticity to a test chromaticity in a trial. Observers judged whether this chromaticity change appeared to be induced by changing the object or by changing the illumination. In the control experiment, observers performed the same task for a stimulus of a mat object without specular highlights. Different values of hue and saturation were used as the test chromaticities. In the results, the chromaticity changes appeared more likely to be caused by changing the illumination when the test color had lower saturation. In addition, the ratios of “illumination changed” responses were slightly higher for objects with specular highlights than for objects without specular highlight. However, the ratios of “illumination changed” responses averaged across observers were not largely different across color directions. These results suggest that specular highlights slightly contribute to the estimation of illumination color, and that the daylight locus does not largely affect the estimation of the illumination color.