• Title/Summary/Keyword: Brightness value

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Automatic Face Identification System Using Adaptive Face Region Detection and Facial Feature Vector Classification

  • Kim, Jung-Hoon;Do, Kyeong-Hoon;Lee, Eung-Joo
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1252-1255
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    • 2002
  • In this paper, face recognition algorithm, by using skin color information of HSI color coordinate collected from face images, elliptical mask, fratures of face including eyes, nose and mouth, and geometrical feature vectors of face and facial angles, is proposed. The proposed algorithm improved face region extraction efficacy by using HSI information relatively similar to human's visual system along with color tone information about skin colors of face, elliptical mask and intensity information. Moreover, it improved face recognition efficacy with using feature information of eyes, nose and mouth, and Θ1(ACRED), Θ2(AMRED) and Θ 3(ANRED), which are geometrical face angles of face. In the proposed algorithm, it enables exact face reading by using color tone information, elliptical mask, brightness information and structural characteristic angle together, not like using only brightness information in existing algorithm. Moreover, it uses structural related value of characteristics and certain vectors together for the recognition method.

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Automatic Contrast Enhancement by Transfer Function Modification

  • Bae, Tae Wuk;Ahn, Sang Ho;Altunbasak, Yucel
    • ETRI Journal
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    • v.39 no.1
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    • pp.76-86
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    • 2017
  • In this study, we propose an automatic contrast enhancement method based on transfer function modification (TFM) by histogram equalization. Previous histogram-based global contrast enhancement techniques employ histogram modification, whereas we propose a direct TFM technique that considers the mean brightness of an image during contrast enhancement. The mean point shifting method using a transfer function is proposed to preserve the mean brightness of an image. In addition, the linearization of transfer function technique, which has a histogram flattening effect, is designed to reduce visual artifacts. An attenuation factor is automatically determined using the maximum value of the probability density function in an image to control its rate of contrast. A new quantitative measurement method called sparsity of a histogram is proposed to obtain a better objective comparison relative to previous global contrast enhancement methods. According to our experimental results, we demonstrated the performance of our proposed method based on generalized measures and the newly proposed measurement.

Physical Parmeters of Late Type Spiral Galaxies - II. Surface Brightness Distribution of NGC 7793

  • Kim, Chang-Ha;Chun, Mun-Suk
    • Journal of Astronomy and Space Sciences
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    • v.3 no.1
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    • pp.53-66
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    • 1986
  • Isophotes and surface brightness distribution were obtained for the late type normal spiral galaxy NGC 7793 (morphological type SA(s)d) which is one of the Sculptor group. The calculated total luminosity $M_{T}$ is obtained as 9.44 and the corrected face on magnitude ${B_T}^{circ}$ is 9.10. The revised distance to this galaxy $\Delta$=3.1 Mpc (de Vaucouleurs and Davoust 1980) is used for calculating the absolute magnitude ${M_T}^{circ}$ = -18.36. From the isophotes, the position angle to the major axis is $101^{circ}$, the mean axial ratio is q=b/a =0.65, and the inclination is i=50$^{circ}$. The concentric indices $C_{21}$=1069 and $C_{32}$ =1.50 are well agreed to the average value of Sd type galaxies.

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PC와 TV겸용 모니터에서의 색채인식

  • Jung, Gwang-Tae;Park, Jae-Hee;Jung, Byung-Gook;Jung, Gil
    • Proceedings of the ESK Conference
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    • 1997.10a
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    • pp.333-338
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    • 1997
  • We performed a study to investigate the characteristics of color perception according to some factors and to suggest the initial setting value of color temperature in each mode of a PC and TV monitor. Investigated factors were monitor coating (coating vs. noncoating)and screen brightness(30fL vs. 35fL). Twenty-three subjects (male 12, female 11) participated in this experiment. The experiment was performed in eachmode of a PC and TV monitor. Average color temperatures were obtained in both PC- mode and TV- mode. In addition, effects of monitor coating and screen brightness were investigated.

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IMAGE PROCESSING TECHNIC USING MEDIAN FILTERING FOR COMET (미디안 필터링을 이용한 혜성의 이미지 처리기법)

  • Park, Y.S.;Lee, C.U.;Jin, H.;Park, J.H.;Han, W.Y.
    • Publications of The Korean Astronomical Society
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    • v.22 no.4
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    • pp.183-187
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    • 2007
  • The detection and measurement of faint features in cometary image is generally troublesome due to the high value of the ratio of the brightness of the nucleus to the tail, the large size and low surface brightness of the coma and tail and the disturbing presence of field stars trails. The image processing is based on background removal by median filtering. Sample results are shown for the case study of comet 73P/Schwassmann-Wachmann 3.

Estimation of surface reflectance properties and 3D shape recovery using photometric matching (물체의 면 반사특성 추정과 측광정합을 이용한 3차원 형상복구)

  • 김태은;류석현;송호근;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.7
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    • pp.1633-1641
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    • 1996
  • In this paper we propose a new method for anlayzing the properties of surface reflectance and reconstructing the shape of object using estimated reflectance parameters. We have investigated the hybrid reflectance surface which has specularreflection and diffuse reflection, which can be explained by Torrance-Sparrow model. Sample sphere made on one maerial is used to estimate the reflectance properties by using LMS algorithm. We can make the reference image which consists of surface normal and brightness value using estimated reflectance parameters, and thenarbitrary shape object made of the same material as sample can be reconstructed by matching with reference image. Photometric matching method proposed in this paper is robust because it mateches object image with the reference imageconsidering its neighbor brightness distribution. Also, in this paper plate diffuse illumination is used to remove intensity disparity with simple scheme. It is expected that the proposed algorithm can be applied to 3D recognition, vision inspection system and other fields.

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A study on the microcontroller-based color control circuit for high brightness LEDs (마이크로컨트롤러를 이용한 고휘도 LED의 광색가변 회로에 관한 연구)

  • Yu, Yong-Su;Song, Sang-Bin;Gwark, Jae-Young;Yeo, In-Seon
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1342-1344
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    • 2000
  • This paper presents a microcontroller-based control circuit for color variation of high brightness RGB LEDs in $8{\times}8$ matrix array. The control circuit is comprised of an AT89C52 chip, D Flip-flops, and transistors for switching, and is used to adjust the number of LEDs operated for color variation. For a stable operation, it is required that the input current to each LED should be maintained to a normal value irrespective of the number of LEDs operated.

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Study of Morphology and Physical Properties of Indian Mallow(Abutilon avicennae Gaertner) Fibers by Image Analyzer (화상분석기를 이용한 어저귀 섬유의 형태학적 특성과 물성연구)

  • 정선화;조남석
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.4
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    • pp.17-22
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    • 2003
  • A kind of image analysis system is used to investigate the structural features of the papers made from Indian mallow. The screen mark on the paper was identified and analyzed. The dusts, shives and fiber bundles were manifested and calculated. In the aspect of Indian mallow hanji's surface characteristics analyzed by an Image analyzer, the average of gray level and its standard deviation hanji from the woody core were rather lower than of bast fiber pulp because of better sheet formation of the formers. Hower. high brightness hanji showed high value of gray level. The sheet formation and paper opacity were increased with the decrease of standard deviation of gray level. From these results, gray level measurement could be used to predict the paper opacity as well as sheet formation.

Implementation of the Panoramic System Using Feature-Based Image Stitching (특징점 기반 이미지 스티칭을 이용한 파노라마 시스템 구현)

  • Choi, Jaehak;Lee, Yonghwan;Kim, Youngseop
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.2
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    • pp.61-65
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    • 2017
  • Recently, the interest and research on 360 camera and 360 image production are expanding. In this paper, we describe the feature extraction algorithm, alignment and image blending that make up the feature-based stitching system. And it deals with the theory of representative algorithm at each stage. In addition, the feature-based stitching system was implemented using OPENCV library. As a result of the implementation, the brightness of the two images is different, and it feels a sense of heterogeneity in the resulting image. We will study the proper preprocessing to adjust the brightness value to improve the accuracy and seamlessness of the feature-based stitching system.

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Mass estimation of halo CMEs using synthetic CMEs based on a full ice-cream cone model

  • Na, Hyeonock;Moon, Yong-Jae
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.2
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    • pp.43.3-43.3
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    • 2019
  • A coronal mass ejection (CME) mass is generally estimated by the total brightness measured from white-light coronagraph observations. The total brightness are determined from the integration of the Thomson scattering by free electrons of solar corona along the line of sight. It is difficult to estimate the masses of halo CMEs due to the projection effect. To solve this issue, we construct a synthetic halo CME with a power-law density distribution (ρ = ρ0r-3) based on a full ice-cream cone model using SOHO/LASCO C3 observations. Then we compute a conversion factor from observed CME mass to CME mass for each CME. The final CME mass is determined as their average value of several CME masses above 10 solar radii. Our preliminary analysis for six CMEs show that their CME mass are well determined within the mean absolute relative error in the range of 4 to 15 %.

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