• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.567-570
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• 2003

A color restoration algorithm for dynamic images under multiple luminance conditions is proposed by using correction vectors, defined for sub regions that the original target is divided into and calculated from color information given in well-illuminated regions. These vectors restore chromatic information of the restored image obtained by the color restoration algorithm in a low luminance condition. Under the condition that the size of dynamic color images in multiple luminance conditions is $320\times240$, experimental results show that the restored image by the proposed algorithm decreases the color-difference about 30％ than that of the restoration algorithm with color change vectors in a low luminance condition. The proposed algorithm aims to construct the surveillance system with a low cost CCD camera in the real world.

• KIEAE Journal
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• v.10 no.4
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• pp.3-8
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• 2010

Recently, various daylight evaluation methods for visual environment have been developed; simulation analysis methods, numerical calculation, and data monitoring methods. However, it is impossible for simulation analysis to make real scenes and visualize real images exactly. Also, a numerical calculation is considered as an out of date and time-consuming mean. Therefore, for acquisition of accurate results, many studies often use the monitoring data methods. Especially, most studies regarding discomfort glare are evaluated by measuring the physical quantity of luminance through traditional measuring Minolta Luminance meters as an instrument. But, this method has a difficulty in measuring several points at the same time because of the limitation of spaces and time when mapping. So, this study focused on the potential usefulness of High Dynamic Range photography technique as a luminance mapping tool. In order to evaluate the accuracy of proposed programs such as webHDR, Photomatix and PHOTOLUX, this paper has conducted an experiment by using Canon EOS 5D and NICON Coolpix8400 digital camera.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.947-950
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• 2008

This paper reports of traceable and repeatable time resolved colorimetric measurements of the luminance- and colour variation occurring during the frame refresh period of FPD's. During one frame period a number of measurements are performed, and for the dynamic artifacts a simulated smooth pursuit eye tracking algorithm is included.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.3
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• pp.81-89
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• 2012

Luminance is the most important quantity in lighting design and illuminating engineering. There are three methods for measuring luminance; using a conventional luminance meter, through the illuminance measurement and subsequent calculations and using digital imaging photometer. Recently, HDRI(High Dynamic Range Imaging) technique introduces a new method of capturing luminance values in a lighting environment. The radiance maps from HDRI are commonly used as visual environment maps for lighting analysis applications. For the HDRI, HDR software is needed to create HDR image. Currently, there is number of HDR software available. The purpose of this paper is to investigate whether a luminance map can be accurately captured by the various types of HDR software which include HDR Shop and Photoshop. To accomplish this goal a set of experiments was conducted. In order to assess the luminance values of the HDR image from HDR software, the values had to be compared to the ones obtained with conventional methods of luminance measurement.

• Journal of Broadcast Engineering
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• v.14 no.4
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• pp.428-437
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• 2009

A high dynamic range (HDR) image can represent real world scenes that have a wide range of luminance intensity. However, compared with the range of real world luminance, conventional display devices have a low dynamic range (LDR). To display HDR images onto conventional displayable devices such as monitors and printers, we propose the logarithmic based global reproduction algorithm that considers the features of the image using reproduction parameters. Based on the characteristics of the image, we first modify the input luminance values for reproducing perceptually tuned images and then obtain the displayable output values directly. The experimental results show that the proposed algorithm achieves good subjective results while preserving details of the image; furthermore, the proposed algorithm has a fast, simple and practical structure for implementation.

• Journal of Information Display
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• v.13 no.4
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• pp.159-166
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• 2012

In this paper, a display's emotional image quality can be primarily determined by designing the proper luminance level. Though displays with high luminance are preferred, too much light emission from a display may cause glare or visual fatigue to viewers. To find out the proper luminance level based on various video contents, this study was conducted with an OLED display with a real-black level and a wide color gamut, and with an LCD display with a high luminance level, to set the glare threshold under various conditions. The optimum luminance levels according to the display's loading ratio were found, and the maximum luminance that did not cause a glare in the test is proposed.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.799-802
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• 2004

In this paper, the active backlight control technology with data processing algorithm was developed in order to improve image quality for IPS-mode LCD-TV applications. The image blinking problem caused by repeatedly abrupt change of the backlight luminance was solved by algorithms-Fba(Flexible Boundary algorithm) and Cfa(Cumulative Feedback algorithm)-and the optimized number and space of backlight dimming steps based on perception. In the IPS-mode 42" TFT-LCD panel, the dynamic contrast ratio can be more than twice the typical level by means of lower block luminance and higher white luminance. Additionally, Power consumption and LCD temperature was decreased.

• ETRI Journal
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• v.38 no.5
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• pp.858-867
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• 2016

A high dynamic range (HDR) video service is an upcoming issue in the broadcasting industry. For compatibility with legacy devices receiving a non-constant luminance (NCL) signal, new tools supporting an HDR video service are required. The current pre-processing chain of HDR video can produce color noise owing to the chroma component down-sampling process for video encoding. Although a luma adjustment method has been proposed to solve this problem, some disadvantages still remain. In this paper, we present an adaptive color noise reduction method for an NCL signal of an HDR video service. The proposed method adjusts the luma component of an NCL signal adaptively according to the information of the luma component from a constant luminance signal and the level of color saturation. Experiment results show that the color noise problem is resolved by applying our proposed method. In addition, the speed of the pre-processing is increased more than two-fold compared to a previous method.

• Journal of IKEEE
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• v.22 no.4
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• pp.901-906
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• 2018

Due to the development of display technologies for images, the resolution and quality of images are increasing day by day. In accordance with the development of the display technology, researches have been actively conducted on technologies for converting and displaying existing images to higher resolution and quality. Since the results of theses studies are included in the image signal processor, hardware implementation is indispensable. In this paper, we propose a real-time HDR(High Dynamic Range) conversion hardware implementation of LDR(Low Dynamic Range) image using luminance distribution. The proposed method extracts the features of the image using the histogram of the luminance distribution, and extends the luminance and color based on the extracted features. In addition, when the proposed method is designed by hardware IP(Intellectual Property) and its performance is verified, 4K DCI(Digital Cinema Image) can be handled at a rate of 30fps at 265.46MHz.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.4
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• pp.161-165
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• 2005

Need of a dimmer function becomes more important with increasing interest on a HDTV for home theater applications. In a conventional AC PDP, a possible method to reduce luminance of a whole Panel is to reduce a total number of sustain pulses and then to change the gray level. However, the reduction of the total sustain number causes the step of luminance to be rough. Moreover, it is impossible to control the luminance of the panel for a given gray level. In this paper, a simple and robust method is proposed to control linearly the luminance of whole panel by applying the asymmetric sustain pulses in the display period of the ADS driving scheme. As the range of luminance control by the proposed method is about $50\%$ for a given gray level. Moreover, it is experimentally verified that the proposed method shows similar dynamic margin performances compare with the conventional method.