Simulation of appearance of objects in low illuminance

在明视和暗视范围之间处于中间亮度或照度水平的颜色视觉称为中间视觉。在中间视觉中，我们感知到与明视不同的颜色，因为不仅是一种颜色，而且杆对视觉反应也有贡献。在这项研究报告中，36个色片在0.01lx到1000lx的6个照度水平下，用单色镜配色方法估计了颜色外观。在测试场中展示测试色卡并用左眼观察，用右眼观察参考场中的自然色彩系统(NCS)颜色图谱。从NCS颜色图谱中选择一个与测试颜色具有相同颜色外观的色块。受试者回答了NCS的四个量表：色调、白度、黑度和色度。实验结果表明，随着照度的降低，(1)色度降低，(2)绿-蓝和黄橙区域发生色调漂移，(3)亮度对比度降低。利用所获得的实验结果，我们开发了一种算法，可以在明视条件下从静止摄像机拍摄的彩色图像中预测中间视觉的颜色外观。

Color vision at an intermediate luminance or illuminance level between photopic and scotopic range is called mesopic vision. In mesopic vision, we perceive different colors from in photopic vision, because not only ones but also rods contribute to the visual response. In this research report, color appearance for 36 color chips under 6 illuminance levels from 0.01 lx to 1000 lx was estimated by a haploscopic color matching method. A test color chip was presented in the test field and observed by the left eye, and the Natural Color System (NCS) Color Atlas in the reference field was observed by the right eye. One color chip which was the same color appearance as the test color was selected from the NCS Color Atlas. Subjects responded four scales of the NCS, hue, whiteness, blackness and chromaticness. The experimental results show that as the illuminance decreased, (1) chromaticness decreased, (2) hue shift was observed in green-blue and yellow-orange regions and (3) brightness contrast decreased.Using obtained experimental results, we have developed an algorithm which can predict color appearance for mesopic vision from color images taken by a still video camera in the photopic condition.