• 한국음향학회:학술대회논문집
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• 한국음향학회 2004년도 춘계학술발표대회 논문집 제23권 1호
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• pp.81-84
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• 2004

In this paper, we propose a virtual sound localization algorithm which improves the sound localization accuracy and sound color preservation for two channel and multi-channel surround speaker layouts. In conventional CPP laws, the sound direction is different from the panning angle and the sound color is different from real sound source especially when the speakers are spread out widely. To overcome this drawback, we design a virtual sound localization algorithm using directional psychoacoustic criteria (DPC) and sound color compensator (SCC). The analysis results show that in the case of the proposed system, the sound direction is the same as the panning angle in the audible frequency range and the sound color is less deviated from a real sound source than the conventional CPP law. In addition, its performance is verified by means of subjective tests using a real sound source.

• 한국멀티미디어학회논문지
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• 제17권7호
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• pp.806-817
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• 2014

The extraction of lip region is essential to Lip Reading, which is a field of image processing to get some meaningful information by the analysis of lip movement from human face image. Many conventional methods to extract lip region are proposed. One is getting the position of lip by using geometric face structure. The other discriminates lip and skin regions by using color information only. The former is more complex than the latter, however it can analyze black and white image also. The latter is very simple compared to the former, however it is very difficult to discriminate lip and skin regions because of close similarity between these two regions. And also, the accuracy is relatively low compared to the former. Conventional analysis of color coordinate systems are mostly based on specific extraction scheme for lip regions rather than coordinate system itself. In this paper, the method for selection of effective color coordinate system and chromaticity transformation to discriminate these two lip and skin region are proposed.

• 한국컴퓨터정보학회논문지
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• 제15권10호
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• pp.59-70
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• 2010

모바일폰이나 디지털 카메라에서 사용하는 영상 센서의 수광 소자는 한 가지 색만을 기록하는 베이어 패턴이기 때문에 각각의 화소들은 여러 개의컬러 중에서단 하나만의 컬러에 대한 화소값을얻게 된다. 잃어버린화소의 정보는 CFA(Color Filter Array)를 이용하여 그 주위의 화소에 대한 정보를 이용함으로 완전한 컬러 영상을 추론한다. 본 논문은 영상 센서의 수광 소자로부터 획득한 데이터의 평균과 각 컬러 채널 데이터 평균 사이의 관계를 유도하고, 이 관계를 이용하여 색상 보간을 위한 효율적인 에지 컬러 퍼지 보간 방법을 제안하였다. 또한 휘도 신호 채널의 보간은 컬러 노이즈를 감소하고 효율적인 보간을 위해 에지 방향에 따라 퍼지 보간을 하였다. 그리고 본 논문에서 PSNR을 이용하여 제안된 방법이 기존 방법보다 평균 2.4dB 정도 개선됨을 증명하였으며, 시각적으로 원영상의 해상도와 유사한 수준이며, 기존 알고리즘의 영상보다 색수차가 감소된 것을 실험 결과를 통하여 확인하였다.

• 대한전자공학회논문지SP
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• 제39권1호
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• pp.1-8
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• 2002

RGB 칼라 필터 배열을 사용한 순차주사 CCD 이미지 센서는 센서의 구조적 한계를 극복하고 칼라 신호의 해상도를 향상시키기 위해 칼라 보간 구조가 필요하다. 기존의 접근 방법을 통해 보간된 결과 영상 대부분에서 경계선은 열화되고 재현된 칼라는 원영상의 칼라와 차이가 났다. 본 논문에서는 순차주사 CCD 이미지 센서를 위한 개선된 경계적응적 칼라 보간 구조를 제안했다. 제안된 경계 표시자(edge indicator) 함수는 채널내 상관관계 뿐만 아니라 채널간의 상관관계를 이용하며 주어진 영상의 경계 특성을 칼라 보간 과정에 적응적으로 반영한다. 주어지지 않은 채널 값은 경계를 거스르는 방향이 아니라 경계 방향을 따라서 보간되고, 에일리어징 현상(aliasing artifacts)은 억제가 됐다. 또한 경계적응적 칼라 보간 구조의 단순한 칼라 영상 형성 모델로부터 발생하는 국소적으로 나타나는 잘못된 색을 칼라 경계 검출법에 기반한 스위칭 알고리즘에 의해 제거하였다. 개선된 경계적응적 칼라 보간 구조는 기존의 접근 방법에 비해 주관적 화질과 객관적 화질 모두 우수한 결과를 실험적으로 보였다.

• 한국연초학회지
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• 제21권1호
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• pp.5-9
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• 1999

In recent years, the line of increase in policy on tobacco production triggered a rise in the loading volume per bulk curing barn, and manufacturers boosted the output of their blowers in order to prevent dirty leaves in the process of curing. for this reason, we studied the effect of the reducing air flow in bulk curing chamber from the color fixing stage to the stem drying stage of flue curing process on physical properties of cured leaves. The control of air flow was composed of the reducing air velocity of blower by means of a voltage regulator (slidac), and condition before color fixing stage was all the same with the conventional curing method. As a result, an effectiveness of improvement in the physical properties of cured leaves were observed. The leaves cured by this method were somewhat orange in color of upper stalk position, better bodied, and less brittle compared with the leaves produced by conventional curing. However, the leaves cured by this method had a little sharpness and harshness. As to the physical properties, there was decreased in occurrence of flat leaves than that of conventional ones. On the other hand, in case of reducing air flow during the curing process, increase of price per kg reached to about 5 % compared with those of conventional curing method.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.389-392
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• 2004

A new dithering algorithm, "Hi-FRC", to enable full (16,777,216) color display on LCD panel with 6-bit source D-IC's is presented. The conventional FRC can display only 16,194,277 colors. In addition, The LCD panel with Hi-FRC can meet the color grayscale linearity of TCO '03 because it can improve the color shift problem.

• Current Optics and Photonics
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• 제6권6호
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• pp.608-618
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• 2022

By analyzing the signal-to-noise ratio (SNR) theory of the conventional true color night vision system, we found that the output image SNR is limited by the wavelength range of the system response λ₁ and λ₂. Therefore, we built a double-channel four-band true color night vision system to expand the system response to improve the output image SNR. In the meantime, we proposed an image fusion method based on principal component analysis (PCA) and nonsubsampled shearlet transform (NSST) to obtain the true color night vision images. Through experiments, a method based on edge extraction of the targets and spatial dimension decorrelation was proposed to calculate the SNR of the obtained images and we calculated the correlation coefficient (CC) between the edge graphs of obtained and reference images. The results showed that the SNR of the images of four scenes obtained by our system were 125.0%, 145.8%, 86.0% and 51.8% higher, respectively, than that of the conventional tri-band system and CC was also higher, which demonstrated that our system can get true color images with better quality.

• 방송공학회논문지
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• 제17권5호
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• pp.851-863
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• 2012

Retinex 기법은 영상의 어두운 영역의 가시성 향상을 통해 영상의 명암대비를 향상시킨다. 그러나 기존 Retinex 방식들은 RGB 색공간에서 수행되기 때문에 색상의 왜곡과 과다한 채도향상으로 인한 색신호 재현의 오류가 발생한다. 본 논문에서는 YCbCr 색공간에서 휘도신호에 대한 Retinex 처리를 통해 명암을 향상시키고, 휘도신호와 색상에 따른 최대 색차신호 테이블을 이용하여 휘도신호의 밝기 변화에 따라 변화된 채도를 밝기에 적응적으로 보정하는 방법을 제안한다. 제안된 방법은 과채도 현상을 막기 위해 휘도와 색상에 따른 채도의 상관관계를 고려하여 색차신호가 올바른 색역에 사상될 수 있도록 한다. 실험을 통해 제안된 방식은 기존 방식에 비해 다양한 특성을 갖는 영상에서 우수한 컬러 향상이 이루어짐을 확인하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.999-1004
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• 2002

This paper presents the color displays using more than three primary colors, for the reproduction of wider color gamut, and high-fidelity color reproduction. First, Natural Vision system, which is currently under development for the natural color reproduction in visual telecommunication applications, is introduced, The natural vision is based on spectrum instead of trichromatic color space, and enables high-fidelity color reproduction using multispectral and multiprimary technologies. Then, sixprimary color projection displays using LCD and DLP, and a four-primary color flat panel display are shown. It is experimentally demonstrated that the color gamut becomes much larger than conventional RGB-based display. In addition, it is proved that the spectral color reproduction using multiprimary display suppresses the influence of observer metamerism, and as a result, the color matching between the display and the real object is well improved.

• Journal of the Optical Society of Korea
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• 제15권2호
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• pp.140-145
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• 2011

Joint transform correlator (JTC) is a well known tool for color pattern recognition for a color image. Color images have red, green and blue components, thus in conventional JTC, three input channels of these color components are necessary for color pattern recognition. This paper proposes a new technique of color pattern recognition by decomposing the color image into three color components and recombining those components into a single gray image in the input plane. This new technique needs single input channel and single output CCD camera, thus a simple JTC can be used. We present various kinds of simulated results to show that our newly proposed technique can accurately recognize and discriminate color differences.