• Journal of the Korean Institute of Intelligent Systems
• /
• v.24 no.4
• /
• pp.424-429
• /
• 2014

In this paper, an image-based luminance measurement system(LMS) is proposed to measure the luminance of outdoor signboards. We design the LMS that can improve disadvantages of efficiency of the point-luminance meter and portability of face-luminance meter using the image of DSLR camera and print out the luminance value by using the proposed luminance analysis algorithm in real time. Outdoor signboards have various size and shape, and are also installed on the various place. Luminance of the signboard is influenced by measurement location, angle, color, etc. Therefore, we measure the change of luminance value in accordance with measurement location for accurate luminance measurement and then consider the luminance value according to the measurement distance. We obtain a numerical relation between luminance value and measurement location. The proposed LMS is verified through comparative experiment with point-luminance meter.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.12
• /
• pp.8649-8653
• /
• 2015

A number of video indexing and retrieval algorithms have been proposed to manage large video databases efficiently. The video similarity measure is one of most important technical factor for video content management system. In this paper, we propose the luminance characteristics model to measure the video similarity efficiently. Most algorithms for video indexing have been commonly used histograms, edges, or motion features, whereas in this paper, the proposed algorithm is employed an efficient similarity measure using the luminance projection. To index the video sequences effectively and to reduce the computational complexity, we calculate video similarity using the key frames extracted by the cumulative measure, and compare the set of key frames using the modified Hausdorff distance. Experimental results show that the proposed luminance projection model yields the remarkable improved accuracy and performance than the conventional algorithm such as the histogram comparison method, with the low computational complexity.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.26 no.4
• /
• pp.321-326
• /
• 2016

In this paper, we propose a luminance correction algorithm based on measuring position for potable luminance measurement system. Measurement position and angle have an affect on the luminance value. We improve the position-based luminance measurement system using luminance correction algorithm based on the measuring angle. We analyze change of luminance value according to the measurement distance and angle from camera and light source. The certified point-luminance meter is used to evaluate a scene luminance measuring method using the image information of camera. Also, we derive an expression equation for evaluating luminance value from determined position. The performances of the proposed system are verified by using comparative experiments with the point-luminance meter using experimental signboard.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.11
• /
• pp.14-19
• /
• 2013

Tunnel lighting design and operation are both regulated based on luminance in and out of Korea these days. However, domestic tunnel lighting is operated by internal lighting depending on external brightness by using an illuminometer applying the conversion factor on luminance. The purpose of tunnel lighting is to alleviate the visual shock occurring from the rapid change from external brightness to internal brightness when entering a tunnel. However, when looking at the tunnels operated based on an illuminometer, it is not a system where the driver can measure the brightness within his or her viewing angle when entering the tunnel. It is general to install and operate the illuminometer on the roof of an administrative office near the tunnel; however, this method is not structured to connect with the internal lighting by checking the brightness of the viewing scope of the driver, thus is not structured to properly apply the viewing conditions of the driver. Rather, it should be in a method for extracting the luminance value within the viewing scope of the driver pursuant to tunnel lighting standards and in connection with internal lighting. This research seeks to find the difference between operations based on luminance and operations based on intensity of Illuminance in road tunnels through field measuring, and to suggest the necessity of operating based on luminance with the resulting value.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.37 no.3
• /
• pp.314-321
• /
• 2024

Low road lighting is a lighting device that complements the shortcomings of existing pillar-type street lights. It is a lighting device that emits light from the side of the road surface and adjusts the luminance of the road surface like a light carpet. In this paper, to achieve full commercialization, we analyzed the luminance of the installed road surface and studied whether lighting could replace existing road lighting. In this study, the LMK (Luminance Measurement Camera) LABSOFT program was used to measure and analyze the surface luminance of road lighting, and the RELUX program was used to evaluate and analyze the simulation performance to determine light-based lighting conditions. A study was conducted to determine whether replacing pillar-type road lighting with low-level road lighting in a real environment would ensure comfortable and safe night vision for drivers at night.

• KIEAE Journal
• /
• v.6 no.4
• /
• pp.25-32
• /
• 2006

Mock-up model can be applied to measure accurate performance data but difficult to apply the variables in experiment. There can be a slight experiment errors in Scale model, but various parameters can be applied for a objective experiment. This paper aims to compare the daylighting performance in 1, 1/5, 1/10 scale model of offices and analyze the experiment errors to certificate the influence of model experiment. To analyse daylighting performance, a comparison of a Mock-up model, sized $12.0m(w){\times}7.2m(l){\times}3.7m(h)$, designed for experimentation of daylighting systems and its 1:5, 1:10 scale model. It has an identical configuration of reference room and the test room. For the test room, the lightshelf system was designed as Micro-4 reflective material. To assess work plane illuminance and light factor, photometric sensors of each room were installed at work-plane(6 points) and exterior horizontal illuminance (1 point). And luminance of window, rare of the room was measured under clear sky. It is to be monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons with a light factor, increase-decrease ratio and luminance are discussed.

• Transactions of Materials Processing
• /
• v.11 no.7
• /
• pp.620-627
• /
• 2002

The purpose of this paper is the development of an automated measurement system for micro spring based on the digital image processing technique. This micro spring can be used in various engineering applications such as filament, load bearing springs, hard disk suspension and many others. Main functionality of the micro spring inspection system is to measure the representative pitch of the micro spring. The derivative operators are used for edge detection in gray level image. Measurement system developed in this paper consisted of new auto feeding mechanism to take advantage of air pressure. In the process of development of the micro spring inspection system based on the image processing and analysis, strong background technology and know-how have been accumulated to measure micro mechanical parts.

• Journal of IKEEE
• /
• v.28 no.1
• /
• pp.90-96
• /
• 2024

In this paper, we propose an automated system. It utilizes a Raspberry Pi camera and a function generator to analyze luminance in an image. Then, it applies voltage based on this analysis to control light transmission through coloring smart windows. The existing luminance meters used to measure luminance are expensive and require unnecessary movement from the user, making them difficult to use in real life. However, after taking a photography, luminance analysis in the image using the Python Open Source Computer Vision Library (OpenCV) is inexpensive and portable, so it can be easily applied in real life. This system was used in an environment where smart windows were applied to detect the luminance of windows. Based on the brightness of the image, the coloring of the smart window is adjusted to reduce the brightness of the window, allowing occupants to create a comfortable viewing environment.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.42 no.3 s.303
• /
• pp.107-114
• /
• 2005

Edge enhanced image is needed for processing images for special purpose such as a circuit diagram or a design composed of lines. Error diffusion halftoning, among digital halftoning methods to represent a continuous grayscale image for the binary output device such as printers, facsimiles, LCD televisions and etc. also makes edges of objects blurred. This paper proposes the method to enhance the edge of a binary image for the binary output device as well as a circuit diagram or a design. Based on that the human eyes perceive the local average luminance rather than the pixel's luminance itself, the proposed system uses a local activitymeasure (LAM), which is the difference between a pixel luminance and the average of its $3{\times}3$ neighborhood pixels' luminances weighted according to the spatial positioning. The system also usesinformation of edge enhancement(IEE), which is computed from the LAM multiplied by the average luminance. The IEE is added to the quantizer's input pixel and feeds into the halftoning quantizer. The quantizer produces the halftone image having the enhanced edge. The simulation results show that the proposed method produces more fine halftoning images than conventional methods due to the enhanced edges. Also the performance of the proposed method is compared with that of the conventional method by measuring the edge correlation and the local average accordance over a range of viewing distances.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.723-728
• /
• 2006

In this paper, we present a new system, OPTISCOPE SA, especially designed for precise measurement of temporal behavior of LCD displays. We show that gray to gray level response time measurement requires a very sensitive and precise instrument and also that the capacity to measure luminance levels and gamma curve can be useful. Quite often, precise evaluation of LCD response time needs also use of low pass and stop band filters to suppress noise and flicker. Low pass filters affect the results but can be corrected for simple temporal behaviors. For complex temporal behaviors like those observed for overdriven LCDs, we show that direct adjustment of theoretical responses is much more efficient to get a complete picture of the temporal behavior of such displays.