• ETRI Journal
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• 제34권5호
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• pp.753-758
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• 2012

As the next-generation video coding standard, High Efficiency Video Coding (HEVC) has adopted advanced coding tools despite the increase in computational complexity. In this paper, we propose a selective bi-prediction method to reduce the encoding complexity of HEVC. The proposed method evaluates the statistical property of the sum of absolute differences in the motion estimation process and determines whether bi-prediction is performed. A performance comparison of the complexity reduction is provided to show the effectiveness of the proposed method compared to the HEVC test model version 4.0. On average, 50% of the bi-prediction time can be reduced by the proposed method, while maintaining a negligible bit increment and a minimal loss of image quality.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.232-235
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• 2008

The mission of the EO(electro-optical) based low earth orbit satellite is provision of the high-resolution images required for GIS(Geographical Information Systems) establishment and the applications for environmental, agriculture and ocean monitoring. AEISS(Advanced Earth Imaging Sensor System) which is the main payload on the satellite consists of EOS(electro-optical subsystem) and PDTS(Payload Data Transmission Sub-system). IDHU(Image Data Handling Unit) which is one of the major unit in PDTS is capable of compression, storage, encryption and encoding. In this paper, the payload system of the EO based satellite is briefly introduced and the influence of the compression on AEISS is analyzed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.144-146
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• 2006

The Data Matrix of two-dimensional bar codes is a new technology capable of holding relatively large amounts of data compared to the conventional one-dimensional bar code which is just a key that can access detailed information to the host computer database. A secret key is used to prevent a watermark from malicious attacks. We encoded copyright information into a Data Matrix bar code for encoding process and it was spread a pseudo random pattern using owner key. We embedded a randomized watermark into the image using watermark's embedding position, pattern generated with a secret key. The experimental results have shown that the proposed scheme has good quality and is very robust to various attacks, such as JPEG compression and noise. Also the performance of the proposed scheme is verified by comparing the copyright information with the information which is extracted from a bar code scantier.

• 한국음향학회지
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• 제13권1호
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• pp.42-48
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• 1994

최근들어 화상 정보처리 분야가 점진적으로 중요시 됨에따라 본논문에서는 정부기관, 경찰서 등의 범죄관련 기관에서 신분 확인용 및 범인 검거용으로 지문을 인식하는데 사용되는 특징점 추출에 관해 기술하였다. 전개과정은 퍼지 이론을 이용하여 세선화를 수행한후 그 화상을 일정 크기의 정사각형 크기로 나누고 8 방향 코드로 부호화한 자료로부터 코아와 델타를 추출하였다. 그 수행결과 $80\%$정도는 정확히 특징점을 추출할 수 있다.

• 한국통신학회논문지
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• 제13권4호
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• pp.302-308
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• 1988

본 논문에서는 벡터 양자화(VQ)의 탐색 복잡도를 줄이기 위한 방법을 제안한다. 본 방법의 현재 부호화하려는 벡터의 특성을 효율적으로 이용함으로써 고속 탐색 효과를 가져온다. 벡터 크기가 16인 제안하는 VQ방식으로써 약 0.1-1.9dB의 미소한 성능 감소로 1/8-1/16의 복잡도 감소를 꾀할 수 있음을 보인다. 동시에 기존의 방식과 비교하여 더 성능이 우수함을 보인다.

• 디지털산업정보학회논문지
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• 제6권2호
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• pp.11-17
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• 2010

In this paper, we propose efficient rate control algorithm for video near-lossless compression. The proposed method adjusts pixel error range using amounts of previous encoded bits and target bits at a slice encoding interval. Thus, encoded bits by the proposed method are transmitted well through limited bandwidth without overflow. Also, target bits and encoded bits can be controlled according to transmission policy. Experimental results show that our proposed method not only almost fits compression ratio, but also has better image quality.

• 한국정보처리학회논문지
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• 제7권11호
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• pp.3462-3469
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• 2000

본 논문에서는 영상 벡터양자화에서의 계산량과 압축률 개선을 위한 새로운 방법을 제안하였다. 제안된 방법은 코드북 부분검색, 코드벡터 요소의 부분사용, 검색 중단조건 등을 이용하여 코드북 구성, 인코딩 과정에서의 계산량을 줄일 수 있었다. 또한, 선택된 코드북 인덱스 무손실 압축에서의 압축률을 높이기 위해 코드북 재배열과 가변길이 코딩(Variable Length Coding)을 사용하였다.

• Journal of Electrical Engineering and information Science
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• 제3권2호
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• pp.222-229
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• 1998

In the circumstances we want to deal with, a transmission channel is limited and a global motion can happen by camera movement, and also there exists a region-of-interest(ROI) which is more important than background. So very low bit rate coding algorithm is required and processing of global motion must be considered. Also ROI must be reconstructed with required quality after decoding because of its importance. But the existing methods such as H.261, H.263 can not reconstruct ROIs with high quality because they do not consider the fact that ROIs are more important than background. So a new coding scheme is proposed that describes a method for encoding image sequences distinguishing bits between ROI and background. Experimental results show that the suggested algorithm performs well especially in the circumstances where background changes and the area of ROI is small enough compared with that of background.

• 전기학회논문지
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• 제56권11호
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• pp.2036-2039
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• 2007

This paper proposes an enhanced adaptive mode decision scheme for fast H.264 encoders. By efficiently predicting AZCB (All Zero Coefficient Block), the proposed scheme can encode motion pictures in H.264 up to 2.86 and 1.68 times faster than JM9.3 and AMD [1], respectively. Besides, this scheme significantly reduces the encoding performance fluctuation of AMD across tested bit-rates and video sequences.

• 반도체디스플레이기술학회지
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• 제20권2호
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• pp.137-140
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• 2021

High dynamic range (HDR) technology has been drawing attention in the field of imaging and consumer entertainment. As tools for capturing and creating HDR contents, encoding, and transmission evolve to support HDR formats, various display capabilities are being developed and increased. Hence, there is need for remapping native HDR imagery for display on lower quality legacy standard dynamic range (SDR) displays. This operation is referred to as tone mapping. In this paper, we present a sectional tone mapping method by Lenzen, and expand upon a tone mapping approach to improve temporal stability while maintaining picture quality. Compared to the existing block-based sectional tone mapping, our method uses the edge awareness-based tone mapping. We estimate the performance of the objective metric on temporal flickering. The experimental result shows that the algorithm maintains a smoother relationship between the output luminance values, and this reveals success in reducing halos and improving temporal stability with adopted edge aware filtering.