• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2013.11a
• /
• pp.67-70
• /
• 2013

본 논문에서는 HEVC(high efficiency video coding)의 후처리 필터 중 하나인 적응적 샘플 오프셋(sample adaptive offset, SAO) 기술을 고속화 하는 방법을 제안한다. 기존의 SAO 는 원 영상과 복원된 영상간의 오차를 최소화하기 위해 각 블록마다 오프셋 값을 계산하므로 연산 복잡도가 매우 높다. 따라서 제안한 방법에서는 다양한 입력 영상에 대한 오프셋 사용빈도를 알아보고, 그 통계를 기반으로 불필요한 오프셋 연산을 생략한다.

• Journal of Broadcast Engineering
• /
• v.21 no.4
• /
• pp.578-591
• /
• 2016

In this paper, the fast encoding algorithm in High Efficiency Video Coding (HEVC) encoder was studied. For the encoding efficiency, the current HEVC reference software is divided the input image into Coding Tree Unit (CTU). then, it should be re-divided into CU up to maximum depth in form of quad-tree for RDO (Rate-Distortion Optimization) in encoding precess. But, it is one of the reason why complexity is high in the encoding precess. In this paper, to reduce the high complexity in the encoding process, it proposed the method by determining the maximum depth of the CU using a hierarchical clustering at the pre-processing. The hierarchical clustering results represented an average combination of motion vectors (MV) on neighboring blocks. Experimental results showed that the proposed method could achieve an average of 16% time saving with minimal BD-rate loss at 1080p video resolution. When combined the previous fast algorithm, the proposed method could achieve an average 45.13% time saving with 1.84% BD-rate loss.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.49 no.11
• /
• pp.64-73
• /
• 2012

In this paper, we propose a method to search for identical videos. The proposed method is spatio-temporal group feature fingerprinting. Frame of video is extracted from fixed rate method and is partitioned into vertical group and horizontal group. Descriptor is made of each group feature that is extracted from binary fingerprinting. Next, use descriptor of original video to build a two type of fingerprinting database and matching with query video. To efficient and effective video copy detection, method have high robustness, independence, matching speed. In proposed method, group feature have high robustness and independence in variable modification of video. Building a original fingerprinting database is able to fast matching with query video. The proposed method shows performance improvement in variable modifications in comparison to the existing methods. Especially, very singular performance in speed improvement is great advantage of this paper.

• Annual Conference of KIPS
• /
• 2011.11a
• /
• pp.1027-1030
• /
• 2011

휴머노이드 로봇 중 초상화를 그리는 로봇이 있지만 다양한 영상을 입력받아 명암 및 그림자까지 그림을 그리는 로봇은 흔하지 않다. 기존의 화가로봇들은 사용자의 얼굴을 영상으로 입력받아 윤곽선만 추출하여 그리는 방식으로, 입력된 영상으로부터 로봇 암을 제어하는 과정에서 제대로 동기화가 이뤄지지 못해 드로잉 속도가 느리고 원본 영상과 비교 시 차이가 많이 난다. 본 연구에서는 입력된 영상으로부터 명암과 그림자를 인식하여 표현해 줌으로써 입체감 있는 그림의 드로잉이 가능하다. 또한, 로봇 암의 미세한 컨트롤을 통해 드로잉 선 두께를 제어함으로써 자연스러운 그림을 그리고, 드로잉 속도가 향상되어 정확도를 높일 수 있게 하는 휴리스틱 암 제어 기술을 제안한다. 이를 구현하기 위해서는 영상으로부터 명암, 그림자의 농도에 따라 레벨을 결정하고, 레벨을 바탕으로 주변 명암 픽셀들을 평활화 하여 좌표 집합을 추출한다. 좌표 값들로 부터 유효 궤적을 분석하여 로봇 암이 이동할 경로를 추출하고, 효율적인 드로잉 기법을 통해 명암을 표현하여 드로잉하려 한다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.8B
• /
• pp.1480-1489
• /
• 1999

In this paper, we propose a new post-processing method which can solve a problem of MSDS(Mean Squared Difference of Slope) method. Using that method the blocking artifacts can significantly be reduced without any restriction, which is a major drawback of block-based DCT compression method. In this approach, the OSLD(Overlapped Sub-Laplacian Distribution) of dequantized block boundary pixel difference values is defined and used to categorize each block of an image into one of four types. Those types are also classified into one of two classes: an edge and a non-edge classes. A slope across the block boundary is used to quantify discontinuity of the image. If an absolute estimated quantization error value of a DCT coefficient is greater than the corresponding quantization step size, it is saturated to the step size in the edge class. The proposed post-processing method can improve not only the PSNR value up to 0.1~O.3 dB but visual quality without any constraints determined by ad-hoc manner.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.05a
• /
• pp.337-342
• /
• 2008

최근 들어 기존의 녹색 바탕 차량 번호판에서, 흰색 바탕의 신 차량 번호판으로 교체되고 있다. 하지만 아직 기존 차량 번호판이 신 차량 번호판으로 전면 교체되지 않아 두 번호판 모두 사용되고 있다. 따라서 주차관리 시스템, 속도위반, 신호 위반 등 무인 카메라를 이용한 시스템에서, 기존 차량 번호판과 신 차량 번호판의 특징에 맞는 인식 시스템이 요구된다. 본 논문에서는 이러한 문제를 해결하기 위해 기존 차량 번호판과 신 차량 번호판을 통합한, 지능형 차량 번호판 인식 시스템을 제안한다. 무인 카메라에서 획득된 차량 영상에서 번호판의 색상 정보를 이용하여 기존 차량 번호판과 신 차량 번호판을 구분한다. 기존 차량 번호판인 경우에는 HSI 컬러 공간을 이용하여 이진화를 적용하며, 신 차량 번호판인 경우에는 블록 이진화를 적용한다. 이진화된 영상을 대상으로 차량의 형태학적 특징을 이용하여 잡음을 제거한 후, 차량 번호판 영역을 추출한다. 추출된 차량 번호판 영역에 대해 Labeling 알고리즘을 적용하여 개별 문자를 추출한다. 추출된 개별 문자는 FCM 알고리즘을 적용하여 인식한다. 제안된 차량 번호판 추출 및 인식 방법의 성능을 평가하기 위해 160장의 기존 차량 영상과 100장의 신 차량 영상을 대상으로 실험한 결과, 제안된 차량 번호판 추출 및 인식 방법이 실험을 통해서 효율적인 것을 확인하였다.

• Convergence Security Journal
• /
• v.19 no.5
• /
• pp.75-84
• /
• 2019

Recently, the value of video as an important data of medical information technology is increasing due to the feature of rich clinical information. On the other hand, video is also required to be de-identified as a medical image, but the existing methods are mainly specialized in the stereotyped data and still images, which makes it difficult to apply the existing methods to the video data. In this paper, we propose an automated system to index candidate elements of personal identification information on a frame basis to solve this problem. The proposed system performs indexing process using text and person detection after preprocessing by scene segmentation and color knowledge based method. The generated index information is provided as metadata according to the purpose of use. In order to verify the effectiveness of the proposed system, the indexing speed was measured using prototype implementation and real surgical video. As a result, the work speed was more than twice as fast as the playing time of the input video, and it was confirmed that the decision making was possible through the case of the production of surgical education contents.

• The Korean Journal of Nuclear Medicine
• /
• v.32 no.5
• /
• pp.414-424
• /
• 1998

Purpose: Cross-modality coregistration of positron emission tomography (PET) and magnetic resonance imaging (MR) could enhance the clinical information. In this study we propose a refined technique to improve the robustness of registration, and to implement more realistic visualization of the coregistered images. Materials and Methods: Using the sinogram of PET emission scan, we extracted the robust head boundary and used boundary-enhanced PET to coregister PET with MR. The pixels having 10% of maximum pixel value were considered as the boundary of sinogram. Boundary pixel values were exchanged with maximum value of sinogram. One hundred eighty boundary points were extracted at intervals of about 2 degree using simple threshold method from each slice of MR images. Best affined transformation between the two point sets was performed using least square fitting which should minimize the sum of Euclidean distance between the point sets. We reduced calculation time using pre-defined distance map. Finally we developed an automatic coregistration program using this boundary detection and surface matching technique. We designed a new weighted normalization technique to display the coregistered PET and MR images simultaneously. Results: Using our newly developed method, robust extraction of head boundary was possible and spatial registration was successfully performed. Mean displacement error was less than 2.0 mm. In visualization of coregistered images using weighted normalization method, structures shown in MR image could be realistically represented. Conclusion: Our refined technique could practically enhance the performance of automated three dimensional coregistration.

• Geophysics and Geophysical Exploration
• /
• v.9 no.1
• /
• pp.10-18
• /
• 2006

We measured the changes in P-wave velocity that occur when injecting $CO_2$ in gaseous, liquid, and supercritical phases into water-saturated anisotropic sandstones. P-wave velocities were measured in two cylindrical samples of Tako Sandstone, drilled along directions normal and parallel to the bedding plane, using a piezo-electric transducer array system. The velocity changes caused by $CO_2$ injection are typically -6% on average, with maximum values about -16% for the case of supercritical $CO_2$ injection. P-wave velocity tomograms obtained by the differential arrival-time method clearly show that $CO_2$ migration behaviour is more complex when $CO_2$ flows normal to the bedding plane than when it flows parallel to bedding. We also found that the differences in P-wave velocity images were associated both with the $CO_2$ phases and with heterogeneity of pore distribution in the rocks. Seismic images showed that the highest velocity reduction occurred for supercritical $CO_2$ injection, compared with gaseous or liquid $CO_$ injection. This result may justify the use of the seismic method for $CO_2$ monitoring in geological sequestration.

• Journal of Communication Design
• /
• v.59
• /
• pp.114-127
• /
• 2017

At present, the research of the method of 'Blank-Leaving' can be easily found in works of arts and architecture, while it can be hardly discovered in the academic research of film and television. However, as a means of expression, 'Blank-Leaving' gives a unique artistic charm to film and television works, and its development has a positive aesthetic effect to film arts. In order to go into details of the thought of 'Blank-Leaving' in movies, this paper firstly discusses the definition of 'Blank-Leaving', the history and social origin of 'Blank-Leaving' as well as its relationship with Taoism and its application in traditional Chinese painting. Secondly, this article analyzes its function and artistic expression in the film and television and the ideas sublimation it brings to people by means of combining the thought of 'Blank-Leaving' in Taoism. Finally, this work put forward the method of innovation and perfection of 'Blank-Leaving' in film and television works. This paper shows that, as a means of expression, 'Blank-Leaving' has not only realized the value of beauty, but also strengthened the public awareness of film arts.