Author Affiliations
Abstract
1 State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University, Hangzhou 310027, China
2 Visual Health and Safety Institute, China National Institute of Standardization, Beijing 100088, China
In this work, a psychophysical experiment is implemented to assess the white sensation of light-emitting diode (LED) lighting in illuminant mode via a categorical judgment method by a panel of 10 observers. The visual data indicates that the higher values of white sensation estimations locate near the Planckian locus within a correlated color temperature (CCT) range of 5000–9000 K. A model of white sensation for LED lighting in illuminant mode is proposed, from which the predicted maximal white sensation locates near the Planckian locus with a CCT of 6622 K, and the 95% white sensation covers a narrow two-dimensional region.
330.1720 Color vision 330.1730 Colorimetry 330.4595 Optical effects on vision Chinese Optics Letters
2015, 13(7): 073301
Author Affiliations
Abstract
1 Institute for Digital Communications, University of Edinburgh, EH9 3JL Edinburgh, UK
2 Innovation Works Germany, EADS Deutschland GmbH, 81663 Munich, Germany
In this paper, a new approach for wireless data transmission within an aircraft cabin is presented. The proposed application enables the transmission of data to a passenger’s user device. As wireless in-flight applications are subject to strict frequency and electromagnetic compatibility (EMC) regulations, the data is transferred by optical wireless transmission, specifically by two-dimensional visual codes. To this end, black-and-white or colored visual code sequences are displayed on the in-flight entertainment screen. These visual codes are captured by the built-in camera of the passenger’s mobile device and are decoded to reconstruct the transmitted data. In order to compensate for frame losses caused by effects like occlusion and motion blur, a temporal forward error correction coding scheme is applied. Transmission experiments within an Airbus A330 cabin mock-up demonstrate the functionality of the implemented system under realistic conditions such as ambient illumination and geometric configuration. Representative user devices are used for evaluation; specifically, a low-cost and a high-end smartphone are employed as receivers. Performance evaluations show that the proposed transmission system achieves data rates of up to 120 kbit/s per individual passenger seat with these user devices. As the user device has no physical connection to the sensitive on-board system, the proposed transmission system provides an intrinsic safety feature.
Image detection systems Optical interconnects Optical devices Multiframe image processing Free-space optical communication Optical effects on vision Photonics Research
2014, 2(5): 05000150
Author Affiliations
Abstract
School of Opto-Electronic Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China
An optical model of bright pupil effect based on Chinese human eye model is presented. The effects of the incident rays angle and the size of pupil on bright pupil effect are analyzed theoretically. For the incident rays with 5°–15° field of view, the spot diagram of emergent light is also presented. With the pupil diameters of 3–8 mm, the intensity distributions formed by emergent light are calculated. The optical model of bright pupil effect based on Chinese human eye provides a suitable model for the related further research studies and applications on bright pupil effect with Chinese eye.
330.4060 Vision modeling 330.4595 Optical effects on vision 330.7326 Visual optics, modeling Chinese Optics Letters
2014, 12(11): 113301
Author Affiliations
Abstract
1 State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China
2 Department of Color Science, Leeds University, Leeds LS2 9JT, UK
We assess the color appearance of the samples with different inks on glossy substrates, five kinds of paper with different gloss levels. The color samples are measured using spectrophotometers under different illuminating/viewing geometries and visually estimated using the psychophysical method of magnitude estimation. The results of the two approaches are compared through the color appearance model of CIECAM02. The experimental data analysis indicates that the 0/45 and 15/0 geometries can be used to describe the two major aspects of gloss effect, the enlargement of color gamut, and the reduction of lightness. The agreement for hue attribute between instrumental measurement and visual assessment is better than those for colorfulness and lightness.
色貌 量度估计 分光光度计 光泽效应 330.4595 Optical effects on vision 330.1730 Colorimetry Chinese Optics Letters
2009, 7(9): 869
Author Affiliations
Abstract
1 State Key Laboratory of Modern Optical Instrumentation, Zhejiang University, Hangzhou 310027, China
2 Department of Colour Science, University of Leeds, Leeds LS2 9JT, UK
Pearlescent coatings become highly popular to the modern generation of color rendering materials due to their unique color effect. However, it is quite challenging to evaluate its color appearance by traditional color measurement. A low-cost camera is a highly efficient device for multi-geometry color appearance estimation for pearlescent bottles, which has been achieved through the camera characterization, sample image capturing, and then mathematical transforming from RGB (red, green, and blue) values to color appearance attributes based on the color appearance model of CIECAM02. A tele-spectroradiometer for physical measurement together with visual assessment is applied for comparison with the camera method to evaluate the accuracy of camera predictions and discuss the applicability of CIECAM02. The experimental results indicate that the camera data have strong correlation with the physical measurement and also fit well with visual data except for a slight slope shift existing in lightness due to a divinable psychophysical magnitude variation for spatial-dependent color samples. Hence it is feasible to estimate the color appearance of pearlescent bottles using a digital camera.
珠光特性 多角度 相机特征化 色貌模型 幅度估计 330.1710 Color, measurement 330.4595 Optical effects on vision 110.2970 Image detection systems Chinese Optics Letters
2009, 7(8): 08744
