The theory of mesopic vision provides an important theoretical foundation for the choice of road lighting sources. Based
upon a number of recent mesopic photometry studies, an equation (<i>E</i><sub><i>mes</i></sub> = <i>B</i>•<i>E</i><sub><i>P</i></sub>) to deduce from the <i>E</i><sub><i>p</i></sub> (photopic
illumination) to Emes (mesopic equivalent illumination) is proposed, where <i>B</i> is instant for modified coefficient. The
coefficient <i>B</i> can be used easily to calculate the mesopic equivalent illumination by using the measuring results of
photopic illumination for different correlated color temperature (CCT) light sources under mesopic light levels. Using
the equation, we analyze the variation of coefficient <i>B</i> with background lighting level of the different correlated color
temperature lighting sources under mesopic vision levels. By calculating the mesopic equivalent illumination of the
different sources, our results showing that the higher correlated color temperature LED sources have better visual effects.
Moreover, the results provide a basis for further studies on the illuminometer, which might be suitable for mesopic vision.
More and more applications need stereoscopic imaging to analyze the characteristic of things, so three-dimensional
information is needed to visualize and analyze. The stereoscopic imaging can be obtained by single camera or two
cameras. There are several approaches for creating stereo images with a single camera. One of the simplest and most
frequently used has been to place an optical adapter in front of the existing lens, and two images are formed by two
beams through one camera lens. Biprism can be used as stereo adapter. As light go through the biprism, an angle
change occurs due to the prism, the light refracted at the two surfaces, angle of the prism α with also reflection index n
determine the angle change δ of the light. And δ is the maximum field of view. Bigger angle of biprism can obtain
bigger range of stereoscopic imaging, however, the larger of the angle of biprism, the larger of lateral color aberration
the biprism caused, which can affect the resolution of the stereoscopic imaging. This paper also analyzes the nonlinear
magnification and color aberration of the biprism stereo adapter.
Photo-electronic imaging system is a discrete imaging system, according to Nyquist sampling theorem, if the maximum
spatial frequency is higher than Nyquist frequency, there is aliasing, and Morie fringe appears on image. The quality of
image is receded and the trueness of color depressed. An optical low pass filter (OLPF) used in front of photo-electronic
imaging sensor, can effectively limit the frequency spectrum width and critically satisfy Nyquist sampling condition.
Thereby, the aliasing will be eliminated and the quality of the image will be improved. This paper analyzes the
characteristics of frequency response of the OLPF and designs a novel system to measure the optical characteristic of the
OLPF. According to the characteristic of birefringent crystal, a light spot will be separated by the OLPF into several light
spots which will be processed by the computer. For the size of light point determined the limit of measurement accuracy
of OLPF's thickness, laser source, which can obtain light point with 2um diameter is used here as a target light point.
Magnified lens are used to improve the precision of the system. Other system used long working distance (WD)
microscope objective. Instead, this novel system uses the standard 100x optical microscope objective (WD<0.2mm) as
magnifying system. In this way, the cost of the system will be reduced in a great deal. The software of the system is also
very powerful, in addition to the basic function image caption and scanning, it can automatically detect the number of
light spots, distance and angles between light spots. The system can accurately measure the distance of point light at a
high resolution of 0.1um, and the measurable thickness of OLPF is from 0.5 to 5mm.