• 한국통신학회논문지
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• 제22권8호
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• pp.1691-1697
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• 1997

This paper presents a new motion compensated error coding method suitable for region based image coding system. Compared with block based conding, the region based coding improves subjective quality as it estimates and compensates 2D (or 3D) translantional, rotational, and scaling motion for each regions. although the region based coding has this advantage, its merit is reduced as bock-DCT (2D-DCT) is used to encode motion-compensated error. To overcome this problem, a new region adaptive motion compensated error coding technique which improver subjective and objective quality in the region boundary is proposed in this paper. In the proposed method, regions with large error are estimated using contour of the regions and contrast between the regions. The regions estiated as those with large error are coded by arbitrarily shaped image segment coding method. The mask information of the coded regions is not transmitted because it is estimated as the same algorithm in the encoder and the decoder. The proposed region adaptive motion conpensated error coding method improves about 0.5dB when it is compared with conventional block based method.

• Journal of Microbiology and Biotechnology
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• 제26권8호
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• pp.1473-1480
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• 2016

This study focused on the variations in the non-coding sequences between ctxB and rstR of various CTX phages. The non-coding sequences of CTX-1 and CTX-cla are phage type-specific. The length of the non-coding region of CTX-1 and CTX-cla is 601 and 730 nucleotides, respectively. The non-coding sequence of CTX phage could be divided into three regions. There is a phage type-specific Variable region between two homologous Common regions (Common regions 1 and 2). The non-coding sequence of RS1 element is similar to CTX-1 except that Common region 1 is replaced by a short RS1-specific sequence. The non-coding sequences of CTX-2 and CTX-cla are homologous, indicating the non-coding sequence of CTX-2 is derived from CTX-cla. The non-coding region of CTX-O139 is similar to CTX-cla and CTX-2; however, it contains an extra phage type-specific sequence between Common region 2 and rstR. The variations in the non-coding sequences of CTX phages might be associated with the difference in the replication efficiency and the directionality in the integration into the V. cholerae chromosome.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
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• pp.53-56
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• 2000

In progressive image coding, if object region that have main contents in image are transmitted prior to the remained region, this method will be very useful. In this paper, the progressive image coding based on SPIHT using object region transmission method by priority is proposed. First, an original image is transformed by wavelet. Median filtering is used about wavelet transformed coefficient region for extracting object region. This extracted object region encoded by SPIHT. Then encoded object region are transmitted in advance of the remained region. This method is good to a conventional progressive image coding about entire original image. Experimental results show that the proposed method can be very effectively used for image coding applications such as internet retrieval and database searching system.

• 한국통신학회논문지
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• 제22권3호
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• pp.469-480
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• 1997

For moving image coding, the variable size of region coding based on local motion is more efficient than fixed size of region coding. It can be applied well to complex motions and is more stable for wide motions because images are segmented according to local motions. In this paper, new image coding method using the segmentation of motion vectors is proposed. First, motion vector field is smoothed by filtering and segmented by smoothed motion vectors. The region growing method is used for decomposition of regions, and merging of regions is decided by motion vector and prediction errors of the region. Edge of regions is excluded because of the correlation of image, and neighbor motion vectors are used evaluation of current block and construction of region. The results of computer simulation show the proposed method is superior than the existing methods in aspect of coding efficiency.

• 한국통신학회논문지
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• 제27권6A호
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• pp.575-583
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• 2002

JBIG2는 2진 영상과 문서 압축을 위한 국제 표준이다. JBIG2 표준은 2진 영상과 문서를 고압축으로 부호화하기 위해 영역 특징에 따라 세 가지 부호화 모드를 제공한다. MMR이나 산술 부호화를 이용하여 비트맵(bitmap)의 부호화를 위한 제너릭 영역(Generic region) 부호화를 한다. 그리고, 텍스트 영역의 부호화를 위해 패턴 매칭(Pattern Matching) 부호화를 하고, 하프톤 영역(Halftone region) 부호화를 위해 하프톤 패턴 부호화(Halftone Pattern Coding)를 한다. 본 논문에서는 JBIG2 부호화를 위해 문서를 라인아트, 하프톤, 텍스트 영역으로 분할한 후 각 영역에 제너릭 영역 부호화, 심벌 매칭 부호화, 하프톤 패턴 부호화를 하는 JBIG2 CODEC을 구현하였다. 문서의 효율적 영역 분할을 위해 윤곽선 추출법을 이용한 영역분할 방법과 웨이브릿 계수분표를 이용한 영역 분할 방법을 함께 적용하여 facsimile 테스트 영상(IEEE-167a)의 경우 2% 정도의 압축률 개선과 주관적 화질의 향상을 얻었다. 또한 임의 모양 하프톤 영역의 부호화를 제안하여 기존 영역 분할 방법에서 인지할 수 없는 임의 모양 하프톤 영역 주변 텍스트의 주관적 화질을 개선하였다.

• 한국정보전자통신기술학회논문지
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• 제9권6호
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• pp.519-525
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• 2016

This paper addresses the framework of object-oriented image coding, describing a new algorithm, based on monodimensional Legendre polynomials, for texture approximation. Through the use of 1D orthogonal basis functions, the computational complexity which usually makes prohibitive most of 2D region-oriented approaches is significantly reduced, while only a slight increment of distortion is introduced. In the aim of preserving the bidimensional intersample correlation of the texture information as much as possible, suitable pseudo-bidimensional basis functions have been used, yielding significant improvements with respect to the straightforward 1D approach. The algorithm has been experimented for coding still images as well as motion compensated sequences, showing interesting possibilities of application for very low bitrate video coding.

• 한국통신학회논문지
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• 제23권9A호
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• pp.2325-2332
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• 1998

In this paper, the quality scalable coding of selected region is presented. If a region is semantically more important than the others, it is appropriate that the image compression shcem is capable of handling the regional semantic difference because the information loss of the region of interest is more severe. We propose the quality scalable coding with its model by interoducing the quality scale parameter. It is more extended and generalized image compression philosophy than te conventional coding. As an implementation of the proposed quality scalable coding, H.263 based scheme is presented. This scheme can control the temporal and spatial quality efficiently, and improve the reconstructed image quality of the region of interest.

• ETRI Journal
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• 제26권4호
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• pp.332-343
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• 2004

One of the recent and most significant technical properties can be expressed as "digital convergence," which is helping lead the technical paradigm into a ubiquitous environment. As an initial trial of realizing a ubiquitous environment, the convergence between broadcasting and telecommunication fields is now on the way, where it is required to develop a scalable video coding scheme for one-source and multi-use media. Traditional scalable video coding schemes have, however, limitations for higher stable picture quality especially on the region of interest. Therefore, this paper introduces an adaptive scanning method especially designed for a higher regional-stable picture quality under a ubiquitous video coding environment, which can improve the subjective quality of the decoded video by most-preferentially encoding, transmitting, and decoding the top-priority image information of the region of interest. Thus, the video can be more clearly visible to users. From various simulation results, the proposed scanning method in this paper can achieve an improved subjective picture quality far better than the widely used raster scan order in conventional video coding schemes, especially on the region of interest, and without a significant loss of quality in the left-over region.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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• pp.2319-2322
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• 2003

We propose ROI(region of interest) image coding application to still image using PSBS(partial significant bitplane shift)method combined with human face region detecting system. PSBS is an encoding algorithm for ROI image coding in JPEG2000, and takes advantages of both generic scaling based method and maximum shift method defined in JPEG2000. The Powerful advantages of PSBS are able to adjusting image quality in ROI and background flexibly, and support arbitrarily shaped ROI coding without coding the shape. In this letter, we show how to compress an image for human face region using PSBS method combined with human face region detecting system, and propose its application.

• 한국정보처리학회논문지
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• 제5권10호
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• pp.2704-2712
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• 1998

본 논문에서는 진단에 중요한 정보를 가진 영역에 대해서 무손실 부호화하고 나머지 영역에 대해서는 손실 부호화를 하여 비트를 효율적으로 할당하는 MRI 영상 압축 방법을 제안한다. 제안한 방법에서는 척추 디스크 질환 인식을 위해 촬영된 MRI 영상을 대상으로, 질환의 특성을 이용하여 중요한 객체가 포함된 부분을 인식한다. 인식된 부분은 의사의 디스크 질환 유, 무의 판단에 중요한 부분이므로 무손실 부호화하고 나머지 부분은 손실 부호화하여 전송한다. 또한 손실 부호화하는 영역에 대해서 웨이브릿 변환 영역에서의 프랙탈 압축 방법을 적용하여 블록화 현상이 제거된 선명한 화질을 유지한다.