• 한국HCI학회:학술대회논문집
• /
• 2008.02a
• /
• pp.33-38
• /
• 2008

본 논문은 핀홀 카메라 모델에 의해 렌더링한 컬러와 깊이 이미지의 후처리에 의한 실시간 필드심도 렌더링 방법을 제안한다. 필드심도 렌더링은 최근의 향상에도, 큰 스케일의 블러링에 필요한 계산 때문에 실용적으로 사용되지 못해 왔다. 본 방법은 이방성 가우시안 필터로 생성된 밉맵 이미지들을 비선형으로 보간하여 필드심도 효과에 필요한 블러링을 수행한다. 모든 계산 과정은 GPU로 가속되어, 안정적이고 확장 가능한 실시간 수행 성능을 확보한다. 또한, 후처리 방식의 두 가지 결점인 강도 누출과 블러링 불연속성을 이방성 가우시안 필터와 블러링 정도를 부드럽게 하여 제거한다. 본 방법은 뛰어난 실시간 성능과 함께 고품질의 필드심도 효과를 생성한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2012.06b
• /
• pp.363-365
• /
• 2012

데이터의 규모 및 활용도, 그리고 사용자 접근성 측면에서 실세계 데이터에서 가장 중요한 이슈가 되는 것은 비디오 데이터이다. 장르나 등장인물, 배경 등이 매우 상이한 대량의 비디오 데이터들이 등장하고 있기 때문에, 통일된 사전지식을 이용한 비디오 데이터 분석이 매우 비현실적이 되어가고 있으며 사전지식을 활용하지 않는 비디오 분석기법의 중요성이 커지고 있다. 본 논문에서는 진화 파티를 필터링과 우점 이미지를 이용하여 비디오 데이터를 분절(Segmentation)하는 기법을 소개한다. 이미지 분절화 과정에서 해결해야 할 난점은 시점 변화 및 움직임 등에 의해 발생하는 사소한 변화가 컴퓨터 관점에서는 무시하기 어려운 큰 변화로 해석될 수 있다는 점이다. 동일장면에서의 시점 변화와 같은 사소한 변화로 인하여 동일 세그먼트를 추정하지 못하는 어려움을 해결하기 위하여 우리는 이미지 일부를 표현하는 파티클의 개체군을 생성하여 협력적인 방식으로 개별 이미지 세그먼트를 표현하는 방법을 개발하였다. 또한 동일 인물의 움직임과 같은 변화에 대응할 수 있도록 진화 파티를 필터링 방법을 컬러 히스토그램 방법과 결합하여 추론 성능을 한층 개선하였다. 실제 TV 드라마에 대하여 수행된 인간 평가자의 분절 평가 결과와 비교하여 제안 방법의 성능을 확인하였다.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.3
• /
• pp.131-136
• /
• 2007

This paper proposes a new approach to eliminate the reflectance component for the detection of text in color images. Color images, printed by color printing technology, normally have an illumination component as well as a reflectance component. It is well known that a reflectance component usually obstructs the task of detecting and recognizing objects like texts in the scene, since it blurs out an overall image. We have developed an approach that efficiently removes reflectance components while preserving illumination components. We decided whether an input image hits Normal or Polarized for determining the light environment, using the histogram which consisted of a red component. We were able to go ahead through the ability to extract by reducing the blur phenomenon of text by light because reflection component by an illumination change and removed it and extracted text. The experimental results have shown a superior performance even when an image has a complex background. Text detection and recognition performance is influenced by changing the illumination condition. Our method is robust to the images with different illumination conditions.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.6
• /
• pp.634-638
• /
• 2018

Haze is a factor that degrades the performance of various image processing algorithms, such as those for detection, tracking, and recognition using an electro-optical sensor. For robust operation of an electro-optical sensor-based unmanned system used outdoors, an algorithm capable of effectively removing haze is needed. As a haze removal method using a single electro-optical sensor, the dark channel prior using statistical properties of the electro-optical sensor is most widely known. Previous methods used a square filter in the process of obtaining a transmission using the dark channel prior. When a square filter is used, the effect of removing haze becomes smaller as the size of the filter becomes larger. When the size of the filter becomes excessively small, over-saturation occurs, and color information in the image is lost. Since the size of the filter greatly affects the performance of the algorithm, a relatively large filter is generally used, or a small filter is used so that no over-saturation occurs, depending on the image. In this paper, we propose an improved haze removal method using color image segmentation. The parameters of the color image segmentation are automatically set according to the information complexity of the image, and the over-saturation phenomenon does not occur by estimating the amount of transmission based on the parameters.

• Journal of Korea Multimedia Society
• /
• v.14 no.4
• /
• pp.529-537
• /
• 2011

In this paper, we propose a stable scale adaptive tracking method that uses centroids of the target colors. Most scale adaptive tracking methods have utilized histograms to determine target window sizes. However, in certain cases, histograms fail to provide good estimates of target sizes, for example, in the case of occlusion or the appearance of colors in the background that are similar to the target colors. This is due to the fact that histograms are related to the numbers of pixels that correspond to the target colors. Therefore, we propose the use of centroids that correspond to the target colors in the scale adaptation algorithm, since centroids are less sensitive to changes in the number of pixels that correspond to the target colors. Due to the spatial information inherent in centroids, a direct relationship can be established between centroids and the scale of target regions. Generally, after the zooming factors that correspond to all the target colors are calculated, the unreliable zooming factors are filtered out to produce a reliable zooming factor that determines the new scale of the target. Combined with the centroid based tracking algorithm, the proposed scale adaptation method results in a stable scale adaptive tracking algorithm. It tracks objects in a stable way, even when the background colors are similar to the colors of the object.

• Korean Journal of Optics and Photonics
• /
• v.21 no.4
• /
• pp.175-178
• /
• 2010

A transmission type color filter based on a thin film Ag-$SiO_2$-Ag etalon was proposed and realized in a quartz substrate. The device could acquire infrared suppressed transmission and wide effective area compared to costly e-beam lithography and laser interference lithography. The FDTD method was introduced to take into account the effect of the dispersion characteristics of the silver metal and the thickness thereof. Three different color filters were devised: The cavity length for the red, green and blue filters were 160 nm, 130 nm, and 100 nm respectively, with the metal layer unchanged at 25 nm. The observed center wavelengths were measured at 650 nm, 555 nm, and 480 nm for the red, green, and blue devices; the corresponding bandwidths were about 120 nm, 100 nm, and 120 nm; and the peak transmission for all was ~60%. Finally the relative transmission was measured to decline with the angle of the incident beam with the rate of 1%/degree.

• 전자공학회논문지 IE
• /
• v.45 no.4
• /
• pp.60-67
• /
• 2008

Skin color is a very important information for an automatic face recognition. In this paper, we proposed a skin region extraction method using color information and skin color model. We use the adaptive lighting compensation technique for improved performance of skin region extraction. Also, using an preprocessing filter, normally large areas of easily distinct non skin pixels, are eliminated from further processing. And we use the modified ST color space, where undesired effects are reduced and the skin color distribution fits better than others color space. Experimental results show that the proposed method has better performance than the conventional methods, and reduces processing time by $35{\sim}40%$ on average.

• Journal of Korea Multimedia Society
• /
• v.4 no.1
• /
• pp.67-74
• /
• 2001

In this paper, we propose a face detection algorithm using the color and shape information in color still images. The proposed algorithm is only applied to chrominance components(Cb and Cr) in order to reduce the variations of lighting condition in YCbCr color space. Input image is segmented by pixels with skin-tone color and then the segmented mage follows the morphological filtering an geometric correction to eliminate noise and simplify the segmented regions in facial candidate regions. Multiple facial regions in input images can be isolated by connected component labeling. Moreover tilting facial regions can be detected by extraction of second moment-based ellipse features.

• Journal of Advanced Navigation Technology
• /
• v.15 no.3
• /
• pp.471-477
• /
• 2011

A wide distribution of CCTV cameras in many public areas can be used not only for video surveillance systems but also for preserving fire occurrence. A proposed approach is based on visual information through a static camera. Video sequences are analyzed to find fire candidates and then spatial analyses procedure for detected fire-like color foreground is carried out. If spatial and temporal variances changes rapidly and close to fire motion, fire candidate is considered as fire.

• Journal of the Korea Computer Graphics Society
• /
• v.11 no.4
• /
• pp.34-38
• /
• 2005

본 논문에서는 대형 스크린 기반 디스플레이 환경에서 시각 커뮤니케이션 증진을 위한 비디오 아바타 생성 기법에 대하여 소개한다. 일반적으로 대형 스크린 기반 가상 환경에서는 스크린으로 투사되는 빛의 변화 때문에 정적 배경을 보장할 수 없다. 뿐만 아니라 카메라 위치 설정이 자유롭지 못하기 때문에 디스플레이 환경 내에 있는 사용자를 대상으로 비디오 아바타를 생성하기 쉽지 않다. 본 논문에서는 적외선 및 필터를 이용하여 가시광선을 차단함으로써 사용자 영역을 쉽게 정의할 수 있도록 하였고, 나란히 배치된 컬러 영상에 실루엣 마스크를 적합하여 배경이 제거된 사용자 컬러 영상을 추출할 수 있도록 하였다. 또한 생성된 스테레오 비디오 아바타 영상은 투영 텍스처를 이용하여 보정된 후 가상세계에 투사되어 입체 디스플레이 된다. 제안된 기법은 일반적인 카메라를 이용하고 있으며, 간단한 조명 조건만 설정해주면 기존의 대형 스크린 기반 프로젝션 환경을 변형하지 않고도 쉽게 설치하여 사용할 수 있기 때문에 많은 활용도가 있을 것이라 기대된다.