• Title/Summary/Keyword: Image brightness

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The effect of mean brightness and contrast of digital image on detection of watermark noise (디지털 영상의 밝기와 대비에 따른 워터 마크 잡음 강도의 차이)

  • Kham, Kee-Taek;Moon, Ho-Seok;Yoo, Hun-Woo;Chung, Chan-Sup
    • Proceedings of the Korean Society for Cognitive Science Conference
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    • 2005.05a
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    • pp.125-129
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    • 2005
  • 디지털 영상물에 대한 저작권을 보호하기 위해 저작권자의 고유한 영상을 기존 디지털 영상에 삽입하는 것을 워터 마킹이라고 부른다. 삽입된 워터 마크가 효과적으로 사용되기 위해서는 영상의 다양한 왜곡이나 변형에도 강건할 수 있게 그 강도가 강해야 하며, 동시에 워터 마크가 삽입된 영상의 왜곡을 식별할 수 없게 그 강도를 약하게 하여야 한다. 비가시성을 유지한 채 가능한 한 강한 워터마크를 삽입하는 것은 워터마크를 적용 하는 데 매우 중요한 문제이다. 대부분의 워터 마크 알고리듬에서 삽입될 워터 마크의 강도는 원영상과 워터마크 영상간의 물리적인 차이에 근거하여 계산된 특정 값으로 고정한 채, 이 값을 모든 영상에 동일하게 적용하고 있다. 인간의 경우 자극의 탐지는 주변 영상의 밝기나 대비 등 여러 요소에 의해 변화되므로 디지털 영상에 삽입된 워터 마크의 탐지도 영상의 특징에 따라서 변화될 수 있다. 본 연구에서는 원영상으로부터 세 수준의 밝기와 세 수준의 대비를 갖는 기본 영상들을 만든 후, 기본 영상에서 탐지될 수 있는 워터 마크의 강도가 변화되는 지를 살펴보았다. 연구 결과 영상의 밝기가 밝아질수록, 대비가 커질수록 지각될 수 있는 워터 마크의 강도는 더 커지는 것으로 나타났다. 또한 회귀분석을 통해 영상의 밝기와 대비에 근거하여 삽입될 워터 마크의 강도를 결정할 수 있는 회귀 식을 만들어 내었다. 이러한 회귀 식은 주어진 영상의 통계 치에 근거하여 워터 마크 강도를 적응적으로 변화시킬 수 있는 알고리듬을 개발하는 데 유용하게 사용될 수 있을 것이다.

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A Study on Nucleus Extraction of Uterine Cervical Pap-Smears (자궁 경부진 핵 추출에 관한 연구)

  • Kim, Kwang-Baek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.8
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    • pp.1699-1704
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    • 2009
  • If detected early enough, cervical cantor may have a good survival rate due to its preneoplastic state. However, the process is so time consuming that a medical expert can handle only a small amount of such examinations. In this paper, we propose a new nucleus extraction algorithm for uterine cervical pap smears in order to mitigate such burdens of medical experts. In the preneoplastic state cytodiagnosis images, it is important to differentiate three main areas - background, cytoplasm and nucleus. Thus, we apply lighting compensation and $3{\times}3$ mask of B channel in order to restore damaged image and remove noises respectively. The cell object is obtained from those clean binarized images with Grossfire algorithm. When there are clusters of cells, the target nucleus can be obtained with repetitive binarization of R channel brightness. In our experiment of using uterine cervical pap smears of 400 magnifications that is common in the diagnostic cytology, our method is able to extract 40 nucleus out of 45 population successfully.

Detection and Classification of Major Aerosol Type Using the Himawari-8/AHI Observation Data (Himawari-8/AHI 관측자료를 이용한 주요 대기 에어로솔 탐지 및 분류 방법)

  • Lee, Kwon-Ho;Lee, Kyu-Tae
    • Journal of Korean Society for Atmospheric Environment
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    • v.34 no.3
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    • pp.493-507
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    • 2018
  • Due to high spatio-temporal variability of amount and optical/microphysical properties of atmospheric aerosols, satellite-based observations have been demanded for spatiotemporal monitoring the major aerosols. Observations of the heavy aerosol episodes and determination on the dominant aerosol types from a geostationary satellite can provide a chance to prepare in advance for harmful aerosol episodes as it can repeatedly monitor the temporal evolution. A new geostationary observation sensor, namely the Advanced Himawari Imager (AHI), onboard the Himawari-8 platform, has been observing high spatial and temporal images at sixteen wavelengths from 2016. Using observed spectral visible reflectance and infrared brightness temperature (BT), the algorithm to find major aerosol type such as volcanic ash (VA), desert dust (DD), polluted aerosol (PA), and clean aerosol (CA), was developed. RGB color composite image shows dusty, hazy, and cloudy area then it can be applied for comparing aerosol detection product (ADP). The CALIPSO level 2 vertical feature mask (VFM) data and MODIS level 2 aerosol product are used to be compared with the Himawari-8/AHI ADP. The VFM products can deliver nearly coincident dataset, but not many match-ups can be returned due to presence of clouds and very narrow swath. From the case study, the percent correct (PC) values acquired from this comparisons are 0.76 for DD, 0.99 for PA, 0.87 for CA, respectively. The MODIS L2 Aerosol products can deliver nearly coincident dataset with many collocated locations over ocean and land. Increased accuracy values were acquired in Asian region as POD=0.96 over land and 0.69 over ocean, which were comparable to full disc region as POD=0.93 over land and 0.48 over ocean. The Himawari-8/AHI ADP algorithm is going to be improved continuously as well as the validation efforts will be processed by comparing the larger number of collocation data with another satellite or ground based observation data.

Monitoring of the Volcanic Ash Using Satellite Observation and Trajectory Analysis Model (인공위성 자료와 궤적분석 모델을 이용한 화산재 모니터링)

  • Lee, Kwon-Ho;Jang, Eun-Suk
    • Korean Journal of Remote Sensing
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    • v.30 no.1
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    • pp.13-24
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    • 2014
  • Satellite remote sensing data have been valuable tool for volcanic ash monitoring. In this study, we present the results of application of satellite remote sensing data for monitoring of volcanic ash for three major volcanic eruption cases (2008 Chait$\acute{e}$n, 2010 Eyjafjallaj$\ddot{o}$kull, and 2011 Shinmoedake volcanoes). Volcanic ash detection products based on the Moderate Resolution Imaging Spectro-radiometer (MODIS) observation data using infrared brightness temperature difference technique were compared to the forward air mass trajectory analysis by the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. There was good correlation between MODIS volcanic ash image and trajectory lines after the volcanic eruptions, which support the feasibility of using the integration of satellite observed and model derived data for volcanic ash forecasting.

The Characteristics of Identical Color Coordination In Contemporary Women's Fashion - Centered on the Collections of Paris, Milan, New York, London - (현대(現代) 여성(女性) 패션에 나타난 동일색채(同一色彩) 코디네이션의 특성(特性) - 파리, 밀란, 뉴욕, 런던 컬렉션 중심(中心)으로 -)

  • Kwon, Hae-Sook
    • Journal of Fashion Business
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    • v.9 no.1
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    • pp.21-33
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    • 2005
  • The main objective of this research was to understand the characteristics of identical color coordination through the analysis of modern female fashion color coordination as they appear in the 'Collections'. Data collection of 2026 was done through review of '$pr\hat{e}t-\grave{a}$-porter Collections' of four cities; Milan, London, New York, Paris. Lastly, statistical analysis of frequency and $X^2$-test and also qualitative interpretation of identical color coordination characteristics were completed. The main findings were; The color coordination of modern women's fashion produces a unified theme, or monochromatic harmony, through the use and coordination of identical colors. The clear contrast of tones portrays a strong image especially in achromatic color coordination, and through the use of texture variation, monochromatic color coordination becomes even more compelling. The tone variation, observed most often in monochromatic color coordination was the black and white contrast, which enhances the simplicity and clarity. Within chromatic color combinations, tone on tone color coordination was achieved by varying brightness. Furthermore, the observation of Faux Camaeu indicates that the coordination of different textures is used often in identical color coordination. While achromatic colors can lead to a hard and rough feeling, it also is compensated through the use of varying textures. In addition, adding variety of textures can add subtle interests to the simplicity of white. Lastly, in all four collections, the chromatic identical color coordination was found more frequently than the achromatic. In Paris, N.Y. & London, the chromatic identical coordination was used more often than chromatic. Milan showed most use of achromatic coordination. The use of the tones showed similar trends in all four collections, with contrasting tone being used most often, followed by similar and identical tones.

A Study on the Characteristics and Improvement Plans of Illuminance, Color Temperature, and Luminous Sources of Contemporary Korean Protestant Church - Focusing on the Churches Constructed in Seoul Since 2010 - (한국 현대 개신교 예배공간의 조도, 색온도, 광원 특성 및 개선방안에 관한 연구 - 2010년 이후 건축된 서울 지역 교회를 중심으로 -)

  • Jun, Ye-Jin;CHoi, Sang-Hun
    • Korean Institute of Interior Design Journal
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    • v.22 no.4
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    • pp.86-93
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    • 2013
  • Illumination in church building has played an important role in making workship space more suitable for divine service. As time has changed, however, the worship space of Protestantism is no longer somber and reverent, but changing into practical and multipurpose space with bright and colorful image. This study investigates intensity of illumination of worship space during day and night respectively and figures out the change of psychological change of congregation in accordance with brightness and color temperature in worship space in order to find out preference and look into the usage and change of illumination in recent Protestantism in compliance with the needs of the time and influence. Then, result value is to be compared to Korean Standard intensity of illumination. Also, the correlation between intensity of illumination and color temperature by Kruithof's curve theory is used to identify the comfortableness of the worship space during day and nigh. And it is a common task of space designers and pastors to map out the worship space in terms of illumination suitable for its own purpose with even more modern and Korean sensibility and to create spiritual space for worshippers by collecting opinions from congregation, the main user of the space. With appropriate usage of illumination in Protestantism worship space, the atmosphere and purpose of worship can be enhanced.

Realtime Facial Expression Data Tracking System using Color Information (컬러 정보를 이용한 실시간 표정 데이터 추적 시스템)

  • Lee, Yun-Jung;Kim, Young-Bong
    • The Journal of the Korea Contents Association
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    • v.9 no.7
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    • pp.159-170
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    • 2009
  • It is very important to extract the expression data and capture a face image from a video for online-based 3D face animation. In recently, there are many researches on vision-based approach that captures the expression of an actor in a video and applies them to 3D face model. In this paper, we propose an automatic data extraction system, which extracts and traces a face and expression data from realtime video inputs. The procedures of our system consist of three steps: face detection, face feature extraction, and face tracing. In face detection, we detect skin pixels using YCbCr skin color model and verifies the face area using Haar-based classifier. We use the brightness and color information for extracting the eyes and lips data related facial expression. We extract 10 feature points from eyes and lips area considering FAP defined in MPEG-4. Then, we trace the displacement of the extracted features from continuous frames using color probabilistic distribution model. The experiments showed that our system could trace the expression data to about 8fps.

Improvement of Color Reproduction Using Gamma and CCT Correction on Small LCD Display for Mobile Phone (휴대폰용 소형 LCD 디스플레이에서 감마 및 상관 색온도 보정을 이용한 색재현 성능 향상)

  • Han Chan-Ho;Sohng Kyu-Ik;Kwon Seong-Geun
    • Journal of Korea Multimedia Society
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    • v.9 no.4
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    • pp.451-459
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    • 2006
  • Color reproduction of small LCD display is quite different from that of standard CRT due to the difference of physical, electrical, and optical characteristics. In this paper, we propose a simple and practical method using gamma and CCT correction for improvement of color reproduction on a small LCD display. First, we investigate characteristics of a small LCD display such as brightness, uniformity, color temperature, white and black balance, and nonlinear gamma. And, we also analyze color reproduction region and CCT trajectory according to LCD's input levels. Finally, the optimum gamma and CCT compensation method using LUT is proposed, and our proposed method was realized at mobile phone without hardware modification. In the experimental results, the result image of proposed algorithm is more close to standard color.

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Backlight Compensation by Using a Novel Region of Interest Extraction Method (새로운 관심영역 추출 방법을 이용한 역광보정)

  • Seong, Joon Mo;Lee, Seong Shin;Lee, Songwook
    • KIPS Transactions on Software and Data Engineering
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    • v.6 no.6
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    • pp.321-328
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    • 2017
  • We have implemented a technique to correct the brightness, saturation, and contrast of an image according to the degree of light, and further compensate the backlight. Backlight compensation can be done automatically or manually. For manual backlight compensation, we have to select the region of interest (ROI). ROI can be selected by connecting the outline of the desired object. We make users select the region delicately with the new magnetic lasso tool. The previous lasso tool has a disadvantage that the start point and the end point must be connected. However, the proposed lasso tool has the advantage of selecting the region of interest without connecting the start point and the end point. We can automatically obtain various results of backlight compensation by adjusting the number of k-means clusters for texture extraction and the threshold value for binarization.

Development of Bolt Tap Shape Inspection System Using Computer Vision Technology (컴퓨터 비전 기술을 이용한 볼트 탭 형상 검사 시스템 개발)

  • Park, Yang-Jae
    • Journal of Digital Convergence
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    • v.16 no.3
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    • pp.303-309
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    • 2018
  • Computer vision technology is a component inspection to obtain a video image from the camera to the machine to perform the capabilities of the human eye with a field of artificial intelligence, and then analyzed by the algorithm to determine to determine the good and bad of production parts It is widely applied. Shape inspection method was used as how to identify the location of the start point and the end point of the search range, measure the height to the line scan method, in such a manner as to determine the presence or absence of the bolt tabs average brightness of the inspection area in a circular scan type value And the degree of similarity was calculated. The total time it takes to test in the test performance tests of two types of bolts tab enables test 300 min, and demonstrated the accuracy and efficiency of the inspection on the production line represented a complete inspection accuracy.