• Title/Summary/Keyword: Controlling the Brightness

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Design and Characteristics of 6-60 Lens for CCTV (CCTV용 6-60 렌즈의 설계 및 특성)

  • Han, Doo-Hee
    • Journal of Convergence Society for SMB
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    • v.6 no.3
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    • pp.85-91
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    • 2016
  • It was difficult to verify the car number or face of inspector in the closed circuit television because of low CCD pixels and low brightness of lens. So CCTV lens should have higher pixels and brightness. In this paper, the design of zoom lens for mega pixel Closed-Circuit Television (CCTV) was introduced. We applied aspheric lens in order to reduce the spherical aberration and distortional aberration. And we applied focal length of 6-60mm, F number of 1.2, 3 million pixel resolution and magnifying power of 10 times. Also we applied infrared correction in order to use the CCTV camera in day and night effectively. These norms are the most powerful in CCTV zoom lens of focal length of 6-60mm. And if we apply this lens to the box style CCTV camera, we can verify the car number or face within 50m. Auto controlling system will be continued.

Gamma Correction for Local Brightness and Detail Enhancement of HDR Images (HDR 영상의 지역적 밝기 및 디테일 향상을 위한 감마 보정 기법)

  • Lee, Seung-Yun;Ha, Ho-Gun;Song, Kun-Woen;Ha, Yeong-Ho
    • Journal of Korea Multimedia Society
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    • v.19 no.5
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    • pp.837-847
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    • 2016
  • Tone mapping for High Dynamic Range(HDR) image provides matching human visual perception between real world scene and displayable devices. Recently, a tone mapping algorithm based on localized gamma correction is proposed. This algorithm is using human visual properties of contrast and colorfulness with background intensity, generating a weight map for gamma correction. However, this method have limitations of controlling enhancement region as well as generating halo artifacts caused by the weight map construction. To overcome aforementioned limitations, proposed algorithm in this paper modifies previous weight map, considering base layer intensity of input luminance channel. By determining enhancement region locally and globally based on base layer intensity, gamma values are corrected accordingly. Therefore, proposed algorithm selectively enhances local brightness and controls strength of edges. Subjective evaluation using z-score shows that our proposed algorithm outperforms the conventional methods.

COLLOIDAL PROPERTIES OF HOLLOW LATICES AND THEIR ROLES IN CONTROLLING COLORIMETRIC PARAMETERS OF COATED PAPER SURFACE

  • Hitomi HAMADA;Yoko SAITO
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 1999.04b
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    • pp.309-314
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    • 1999
  • With a view to seek the influence of hollow sphere pigments of latex upon the printed color on coated paper surface, the hollow sphere pigments were compared with filled ones in a variety of experimental approaches. Colloidal properties of latices were determined by measuring zeta potential and particle size distribution. For the amphoteric filled sphere pigment of latex, the polarity was reversed from the negative side to the positive side with decreasing pH. An extraordinarily high peak in the particle size distribution of the amphoteric filled evidenced aggregation between latex particles near the isoelectric point, depending on the electrolyte concentration and pH of the suspending medium. Coated papers containing the hollow sphere pigment in their coating improved optical properties like gloss and brightness. Optical parameters solely of the coating could account for this finding. An equation derived from the Kubelka-Munk equation calculated them fro twice measurements of reflectance of a coated paper over two substrates of different reflectances. This method permitted to predict brightness of coated paper of which coat weight would be different fro the actual one. The colorimetric parameters of solid-printed surfaces of the coated papers closely related to optical and structural properties of the coated papers. The color of the printed surfaces was dominated by the brightness and the smoothness of the coated papers. The hollow sphere pigments were proved to improve optical properties of coated paper and to control minutely colorimetric parameters of printed surfaces.

Video Backlight Compensation Algorithm Based on Reliability of Brightness Variation (밝기 변화량의 신뢰도에 기반한 역광 비디오 영상의 보정 알고리듬)

  • Hyun, Dae-Young;Heu, Jun-Hee;Kim, Chang-Su;Lee, Sang-Uk
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.47 no.6
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    • pp.117-126
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    • 2010
  • In the case of failure images with controlling lighting like backlighting and excessive frontlinghting, the compensation scheme for a specific area in an image is required. The interested region is first selected by user in our method to compensate the first frame. Then we define the matching function of brightness and energy function is proposed with weight of matching function and the relationship among the neighbors. Finally, the energy is minimized by the graph-cut algorithm to compensate the brightness of the first frame. Other frames are straightforwardly compensated using the results of the first frame. The brightness variations of the previous frame is transmitted to the next frame via motion vectors. The reliability of the brightness variation is calculated based on the motion vector reliability. Video compensation result is achieved by the process of the image case. Simulation show that the proposed algorithm provides more natural results than the conventional algorithms.

Smart Emotional lighting control method using a wheel interface of the smart watch (스마트워치의 휠 인터페이스를 이용한 스마트 감성 조명 제어)

  • Kim, Bo-Ram;Kim, Dong-Keun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.8
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    • pp.1503-1510
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    • 2016
  • In this study, we implemented the emotional light controlling system by using the wheel interface built in the smart-watch devices. Most previous light controlling systems have been adopted the direct switches or smart-phone applications for presenting individual emotion in lighting systems. However, in order to control color properties, these studies have some complicated user-interfaces in systems and limitation to present various color spectrums. Therefore, we need to user-friendly interfaces and functions for controlling properties of the lightning systems such as color, tone, color temperature, brightness, and saturation in detail with the wheel interface built in the smart-watch devices. The system proposed in the study is given to choose the user's selecting the emotional status information for providing the emotional lights. The selectable emotional status such as "stable", "surprise", "tired", "angry", etc. can be among 11 kinds of emotional states. In addition, the designed system processed the user's information such as user's emotional status information, local time, location information.

An Approach to Improve the Contrast of Multi Scale Fusion Methods

  • Hwang, Tae Hun;Kim, Jin Heon
    • Journal of Multimedia Information System
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    • v.5 no.2
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    • pp.87-90
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    • 2018
  • Various approaches have been proposed to convert low dynamic range (LDR) to high dynamic range (HDR). Of these approaches, the Multi Scale Fusion (MSF) algorithm based on Laplacian pyramid decomposition is used in many applications and demonstrates its usefulness. However, the pyramid fusion technique has no means for controlling the luminance component because the total number of pixels decreases as the pyramid rises to the upper layer. In this paper, we extract the reflection light of the image based on the Retinex theory and generate the weight map by adjusting the reflection component. This weighting map is applied to achieve an MSF-like effect during image fusion and provides an opportunity to control the brightness components. Experimental results show that the proposed method maintains the total number of pixels and exhibits similar effects to the conventional method.

Maximum Current Estimation Method for the Backup of Current Sensor Faults

  • Kim, Jae-Yeon;Park, Si-Hyun;Suh, Young-Suk
    • Journal of information and communication convergence engineering
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    • v.18 no.3
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    • pp.201-206
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    • 2020
  • This paper presents a new method for controlling the current of lighting LEDs without current sensors. This method can be used as backup against LED current sensor faults. LED lighting requires a circuit with a constant current in order to maintain the same brightness when the ambient temperature changes. Therefore, we propose a new current estimation method to provide backup in case of current sensor faults based on the calculation of the inductor current. In the fabricated circuit, the average current changes from 144.03 mA to 155.97 mA when the ambient temperature changes from 0℃ to 60℃. The application of this study can enable the fabrication of a driving IC for LEDs in the form of a single chip without sensing resistors. This is expected to reduce the complexity of the peripheral circuit and enable precise feedback control.

Design of Path Prediction Smart Street Lighting System on the Internet of Things

  • Kim, Tae Yeun;Park, Nam Hong
    • Journal of Integrative Natural Science
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    • v.12 no.1
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    • pp.14-19
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    • 2019
  • In this paper, we propose a system for controlling the brightness of street lights by predicting pedestrian paths, identifying the position of pedestrians with motion sensing sensors and obtaining motion vectors based on past walking directions, then predicting pedestrian paths through the route prediction smart street lighting system. In addition, by using motion vector data, the pre-treatment process using linear interpolation method and the fuzzy system and neural network system were designed in parallel structure to increase efficiency and the rough set was used to correct errors. It is expected that the system proposed in this paper will be effective in securing the safety of pedestrians and reducing light pollution and energy by predicting the path of pedestrians in the detection of movement of pedestrians and in conjunction with smart street lightings.

Selection of a Remote Phosphor Configuration to Enhance the Color Quality of White LEDs

  • Anh, Nguyen Doan Quoc;Le, Phan Xuan;Lee, Hsiao-Yi
    • Current Optics and Photonics
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    • v.3 no.1
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    • pp.78-85
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    • 2019
  • The remote phosphor structure has been proven to bear greater luminous efficiency than both the conformal phosphor and in-cup phosphor structures; however, controlling its color quality is much more challenging. To solve this dilemma, various researchers have proposed dual-layer phosphor and triple-layer phosphor configuration as techniques to enhance the display brightness of white LEDs (WLEDs). Likewise, this study picked one of these configurations to utilize in multichip WLEDs with five distinct color temperatures in the range from 5600 to 8500 K, for the purpose of improving the optical properties of WLEDs, such as color rendering index (CRI), color quality scale (CQS), luminous efficacy (LE), and chromatic homogeneity. According to the results of this research, the triple-layer phosphor configuration has superior performance compared to other configurations in terms of CRI, CQS, and LE, and yields higher chromatic stability for WLEDs.

Study of cotton linter pre-treatment process for producing high quality regenerated fibers for fabrics (방직용 고품질 재생섬유 제조를 위한 면린터 전처리공정에 관한 연구)

  • Park, Hee Jeong;Han, Jung Su;Son, Ha Neul;Seo, Yung Bum
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.3
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    • pp.27-35
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    • 2013
  • Cotton linter pre-treatment methods using electron beam and sulfuric acid were investigated to prepare high quality regenerated fibers for fabrics. So far, NaOH was used to reduce the degree of polymerization (DP) of the cotton linter for ease of dissolving by cellulose solvent. Two pre-treatment methods were developed to reduce the consumption of the chemicals (NaOH) and to control the DP of cellulose more precisely. Changes in ${\alpha}$-cellulose contents and brightness by the pre-treatments were also important concerns. Both electron beam irradiation and sulfuric acid were shown to be effective on controlling the DP of cellulose and to reduce the chemical consumption, but reduced ${\alpha}$-cellulose contents as well in this study. Sulfuric acid pre-treatment, which needed additional washing process after the pre-treatment when comparing to the electron beam irradiation method, gave the highest brightness and the highest reduction of ${\alpha}$-cellulose content.