• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2008.11a
• /
• pp.267-270
• /
• 2008

H.264|AVC는 인트라 부호화 효율을 높이기 위해 공간 영역에서 주변 화소를 이용하여 다양한 방향에 대한 율-왜곡 최적화 기법을 사용하여 최적의 인트라 예측 모드를 선택한다. 하지만 율-왜곡 최적화 기법을 사용함에 따라 인트라 부호화에 높은 복잡도가 필요하게 되었다. 따라서 본 논문에서는 인트라 예측 모드 결정의 연산 복잡도를 감소시키고자 사전에 인트라 4x4 예측 모드들의 SATD(Sum of Absolute Transform Difference)를 계산하여 조기에 최우선 모드(Most Probable Mode)를 선택하는 방법을 제안하고, SATD의 값에 따라 제한된 후보 모드에 대해서만 율-왜곡 최적화를 수행하여 연산 복잡도를 감소하는 방법을 제안한다. 또한 Vertical, Horizontal 그리고 DC모드는 인트라 $4{\times}4$와 인트라 $16{\times}16$의 공통적인 모드이므로 인트라 $4{\times}4$에서 계산되어진 SATD값을 이용하여 인트라 $16{\times}16$에서의 SAD 계산 복잡도를 줄이는 방법을 제안한다. 본 논문에서 제안하는 빠른 인트라 예측 모드 결정 기법은 연산 복잡도는 평균 61.4% 감소 시킨 반면 부호화 손실은 평균 3.09%에 불과하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.48 no.5
• /
• pp.72-83
• /
• 2011

In this paper, we propose a method to detect and recover the occluded parts of face images using the correlation between pairs of pixels. In a training stage, correlation coefficients between every pairs of pixels are calculated using the occlusion-free face images. Once a new occluded face image is shown, the occluded area is detected and recovered using the correlation coefficients obtained in the training stage. We compare the performance of the proposed method with the conventional method based on PCA. The results show that the proposed method detects and recovers occluded area with much smaller noises than the conventional PCA based method. Moreover, recovered images by the proposed method were more smooth with reduced blurring effect.

• Journal of Broadcast Engineering
• /
• v.14 no.6
• /
• pp.742-748
• /
• 2009

Most commercial digital still cameras use a single sensor array (e.g., CMOS or CCD) with color filter array (CFA) to reduce the cost and size. Since the image obtained with CFA has only one color value per pixel, the demosaicing is needed to acquire missing two color values. Although many demosaicing methods have been proposed, they still have artifacts such as rainbow and zippering artifact. In this paper, we propose the simple demosaicing algorithm using tendency of neighbor pixels with the enhanced weighting function. In the experimental results, our algorithm shows much better subjective qualities of the images than conventional demosaicing algorithm and improves objective qualities.

• Journal of Korea Multimedia Society
• /
• v.6 no.6
• /
• pp.1000-1007
• /
• 2003

In this paper, we propose an efficient method for locating lip. The lip shape is represented as a set of points based on Point Distribution Model. We use the Isodata clustering algorithm to find clusters for all training data. For each cluster, a lip shape model is calculated using principle component analysis. For all training data, a lip boundary model is calculated based on the pixel values around the lip boundary. To decide whether a recognition result is correct, we use a cost function based on the lip boundary model. Because of using different models according to the lip shapes, our method can localize correctly the flu far from the mean shape. The experiments have been performed for many images, and show correct recognition rate of 92%.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2012.11a
• /
• pp.151-154
• /
• 2012

본 논문에서는 화상통신의 현실감을 증진시킬 수 있는 화자 간 시선 맞춤 시스템을 제안한다. 제안하는 방법은 Kinect 거리 카메라로부터 입력된 영상에서 화자의 얼굴 영역을 획득하여 화자의 시선이 카메라를 응시하도록 획득한 영역을 변환한 후에 원본 영상과 합성한다. Kinect 거리 카메라에서 획득한 얼굴 영역에는 다양한 형태의 잡음이 많아 미디언 필터와 모폴로지 연산을 통해 얼굴 영역의 잡음을 제거한다. 화자의 위치에 상관 없이 화자가 카메라를 응시하는 영상을 생성하기 위해서 Kinect 가 제공하는 거리 정보를 이용하여 시선 보정 각도와 회전 축을 획득한다. 시선이 보정된 얼굴 영역은 원본 영상에서 존재하지 않는 영역을 포함하고 있기 때문에, 원본 영상의 각 화소를 삼각형 메쉬로 구성한 후 해당 영역을 보간하여 최종적으로 시선이 보정된 영상을 생성한다. 제안하는 방법은 시선 맞춤 영상을 생성하는 데 필수적인 눈과 주변 얼굴 영역만 선택해서 변환하므로 영상의 왜곡이 적고 실시간 처리가 가능하다는 장점이 있다. 또한 카메라와 화자 사이의 거리 정보를 이용해 화자의 위치에 적응적인 시선 맞춤 영상을 생성할 수 있다. 실험을 통해 Intel i5 CPU 를 장착한 PC에서 $320{\times}240$ 크기의 영상을 사용할 경우 초당 약 35 프레임의 보정된 영상을 생성하여 제안하는 방법이 실시간 처리가 가능하다는 것을 확인하였다.

• The Journal of the Korea Contents Association
• /
• v.3 no.4
• /
• pp.23-28
• /
• 2003

This paper describes, in order to extract contour from topographic map image, an adaptive segment-length thresholding using a threshold depended on target image. First of all, after recognizing the primary symbols and detecting two edges from the projection histogram of the elevation value area, the threshold value is determined by the distance between the edges. Then, the subdivision is peformed by searching a branch point and erasing its neighboring Hack pixels. And contour components are extracted by segment-length thresholding. The experimental result shows that the final image contains non-contour component of 2.41% and contour one of 97.59%.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.4
• /
• pp.75-79
• /
• 2009

In this paper the method was proposed which uses ${\lambda}$-fuzzy measure to detect the edge of the features of the face region. In the conventional method the features was founded using valley, brightness and edge. This method had its drawbacks that it is so sensitive to the external noises and environments. This paper proposed ${\lambda}$-fuzzy measure to cope with this drawbacks. By considering each weight of the pixels the integral evaluation was considered using the center of area method. Thus the continuity of the edge was kept by way of the neighborhood information and the reduction of time complexity wad resulted in.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2000.12a
• /
• pp.149-152
• /
• 2000

A scanner is an output device that scans documents, photographs, films etc, and convert them to digital data. Especially, a film scanner is used for scanning negative/positive films. In this paper, we design step motor control part, image sensor part, and Aか converter part which are components of the scanner and use DSP for fast signal processing. We also design the interface circuits using EPLD between these peripherals and DSP. The PC interface circuits between scanner and PC are designed by using parallel port to control and transfer the scanned data from scanner to PC. For 35mm film, we design hardwares which obtain high resolution more than 9 million pixels (horizontal resolution is 3835 and vertical resolution is 2592).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.17 no.3
• /
• pp.257-264
• /
• 1999

The lens distortions were corrected directly using the high-order polynomial which was offered in camera calibration data for the forward transformation and the root of Newton-Raphson's $2\times{2}$ nonlinear system for the backward transformation. The 0.04~0.08 pixels increase in accuracy was indicated through the use of direct correction of lens distortions instead of least square methods of commercial software. The least square adjustment method of high-order polynomial requires many control points which has a same weight. But this suggested method which is unnecessary to determine control points was developed and applied. The algorithm showed improved efficacy.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.19 no.5
• /
• pp.615-621
• /
• 2009

TFT-LCD image consists of ununiform background, random noises and target defect signal components. Defects in TFT-LCD have some intensity variations compared to background region. It is sometimes difficult for human inspectors to figure out. In this paper, we propose multi-level threshold scheme for detection of the real defect using probability density function with Parzen Window. The experimental results show that the proposed algorithms produce promising results and can be applied to automated inspection systems for finding defects in the TFT-LCD image.