Development of the imaging system based on mesopic vision

本研究的目的是开发一套中间视觉色貌再现成像系统。我们使用数码相机作为输入设备，使用CRT显示器和LCD显示器等各种显示器，甚至使用硬拷贝作为输出设备。人类视觉系统的照度范围从10^5lx到10^&lt；-3&gt；lx。这种大的动态范围是通过视网膜中的两种感光器实现的，即视杆细胞和视锥细胞。当视杆和视锥都处于活动状态时，存在照度级别。我们已经测量了这些照度水平下色片的颜色外观。中间视与明视或暗视的色相不同。在本研究中，我们发展了中间视觉色貌模型。通过比较任意照度下的真实图像和模型预测的虚像来评价模型的性能。最后，我们提出了一种从传统数码相机的输出中获取视锥刺激值和视杆刺激值的方法。使用了大量的测色图进行比色校准。在色差ΔE^*中，校准精度小于3。然后，我们提出了一个成像系统，它可以提供任何自然场景在任何照度水平下的彩色外观。我们还将人类视觉的空间频率特性应用到中间视觉成像系统中。

The purpose of this study is to develop the imaging system for mesopic color appearance reproduction. We used an digital camera as an input device and various displays such as the CRT display and the LCD display and even hardcopies as output devices.Human visual system covers a wide range illuminance range from 10^5lx to 10^<-3>lx. This wide dynamic range is achieved with two kinds of photoreceptors in the retina, rods and cones. There are illuminance levels where both rods and cones are active. We have already measured color appearance of color chips under those illuminance levels. Color appearance in mesopic vision differs from that in photopic or scotopic vision. In the present study, we developed the mesopic color appearance model. We compared the real image under any illuminance and the imaginary image predicted by our model to evaluat the performance of our model.Finally we proposed the method to get cone stimulus values and rod stimulus values from the output of the conventional digital camera. The colorimetric calibration was done using a lot of color test charts. The accuracy of the calibration was less than 3 in color difference ΔE^* . Then, we propose an imaging system that provides color appearance of any natural scene under any illuminance level. We also applied the spatial frequency characteristics of human vision to the mesopic imaging system.