• 제목/요약/키워드: image coding

검색결과 1,162건 처리시간 0.023초

3D Volumetric Medical Image Coding Using Unbalanced Tree (3차원 불균형 트리 구조를 가진 의료 영상 압축에 대한 연구)

  • Kim, Young-Seop;Cho, Jae-Hoon
    • Journal of the Semiconductor & Display Technology
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    • 제5권2호
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    • pp.19-25
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    • 2006
  • This paper focuses on lossy medical image compression methods for medical images that operate on three-dimensional(3-D) irreversible integer wavelet transform. We offer an application of unbalanced tree structure algorithm to medical images, using a 3-D unbalanced wavelet decomposition and a 3-D unbalanced spatial dependence tree. The wavelet decomposition is accomplished with integer wavelet filters implemented with the lifting method. We have tested our encoder on volumetric medical images using different integer filters and coding unit sizes. The coding unit sizes of 16 slices save considerable dynamic memory(RAM) and coding delay from full sequence coding units used in previous works. If we allow the formation of trees of different lengths, then we can accomodate more transaxial scales than three. The encoder and decoder can then keep track of the length of the tree in which each pixel resides through the sequence of decompositions. Results show that, even with these small coding units, our algorithm with certain filters performs as well and better in lossy coding than previous coding systems using 3-D integer unbalanced wavelet transforms on volumetric medical images.

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A Study on Binary Image Compression Using Morphological Skeleton (수리 형태학적 세선화를 이용한 이진 영상 압축)

  • 정기룡
    • Journal of the Korean Institute of Navigation
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    • 제19권3호
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    • pp.21-28
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    • 1995
  • Mathematical morphology skeleton image processing makes many partial skeleton image planes from an original binary image. And the original binary image can be reconstructed without any distortion by summing the first partial skeleton image plane and each dilated partial skeleton image planes using the same structuring element. Especially compression effects of Elias coding to the morphological globally minimal skeleton(GMS) image, is better than that of PCX and Huffman coding. And then this paper proposes mathematical morphological GMS image processing which can be applied to a binary image transmitting for facimile and big size(bigger than $64{\times}64$ size) bitmap fonts storing in a memory.

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The Method of fast Fractal Image Coding (고속 프랙탈 영상 부호와 기법)

  • Kim, Jeong-Il;Song, Gwang-Seok;Gang, Gyeong-In;Park, Gyeong-Bae;Lee, Gwang-Bae;Kim, Hyeon-Uk
    • The Transactions of the Korea Information Processing Society
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    • 제3권5호
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    • pp.1317-1328
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    • 1996
  • In this paper, we propose a fast image coding algorithm to shorten long time to take on fractal image encoding. For its Performance evaluation, the algorithm compares with other traditional fractal coding methods. In the traditional fractal image coding methods, an original image is contracted by a factor in order to make the corresponding image to be compared with. Them, the whole area of the contracted image is searched in order to find the fixed point of contractive transformation of the orignal image corresponding to the contracted image. It needs a lot of searching time on encoding However, the proposed algorithm considerable reduces encoding time by using scaling method and limited search area method. On comparison of the proposed algorithm with Joaquin's method, the proposed algorithm is at least 180 times as fast as that of Jacquin's method on encoding time with a little degradation of the decoded image quality and a little increase of the compression rate. There-for, it is found that the proposed algorithm largely improves the performance in the aspect of encoding time when compared with other fractal image coding methods.

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Enhanced Coding Method by Remapping of Integral Images (집적 영상 재배치를 통한 부호화효율 향상 방법)

  • Kim, Su-Bin;Kang, Hyun-Soo
    • The Journal of the Korea Contents Association
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    • 제15권2호
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    • pp.1-10
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    • 2015
  • In this paper, we propose an integral image compression method to improve the coding efficiency. As the characteristics of integral images are various according to the distance between a camera and objects, complexity of the objects and background, etc, the coding efficiency can be improved by applying a coding method adaptive to the characteristics. In addition, as the integral images are compressed by the unit of elemental images, the coding efficiency can be improved. by employing a coding method optimized to the coding direction of elemental images. Therefore, the proposed method remaps an integral image with six kinds of mapping rules, and then the conventional 3D-DCT based compression method is applied to the remapped images. Finally, we perform the rate-distortion optimization to choose the best of the mapping rules. Experimental results show that the proposed method yields high gains in image quality and bit-rate.

Multiple Description Coding using Whitening Ttansform

  • Park, Kwang-Pyo;Lee, Keun-Young
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2002년도 ITC-CSCC -2
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    • pp.1003-1006
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    • 2002
  • In the communications systems with diversity, we are commonly faced on needing of new source coding technique, error resilient coding. The error resilient coding addresses the coding algorithm that has the robustness to unreliability of communications channel. In recent years, many error resilient coding techniques were proposed such as data partitioning, resynchronization, error detection, concealment, reference picture selection and multiple description coding (MDC). Especially, the MDC using correlating transform explicitly adds correlation between two descriptions to enable the estimation of one set from the other. However, in the conventional correlating transform method, there is a critical problem that decoder must know statistics of original image. In this paper, we propose an enhanced method, the MDC using whitening transform that is not necessary additional statistical information to decode image because the DCT coefficients to apply whitening transform to an image have uni-variance statistics. Our experimental results show that the proposed method achieves a good trade-off between the coding efficiency and the reconstruction quality. In the proposed method, the PSNR of images reconstructed from two descriptions is about 0.7dB higher than conventional method at the 1.0 BPP and from only one description is about 1,8dB higher at the same rate.

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A Coding Mode Image Characteristics-based Fast Direct Mode Decision Algorithm (코딩 모드 영상 특성기반의 고속 직접모드 결정 알고리즘)

  • Choi, Yung-Ho;Han, Soo-Hee;Kim, Lark-Kyo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • 제61권8호
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    • pp.1199-1203
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    • 2012
  • H.264 adopted many compression tools to increase image data compression efficiency such as B frame bi-directional predictions, the direct mode coding and so on. Despite its high compression efficiency, H.264 can suffer from its long coding time due to the complicated tools of H.264. To realize a high performance H.264, several fast algorithms were proposed. One of them is adaptive fast direct mode decision algorithm using mode and Lagrangian cost prediction for B frame in H.264/AVC (MLP) algorithm which can determine the direct coding mode for macroblocks without a complex mode decision process. However, in this algorithm, macroblocks not satisfying the conditions of the MLP algorithm are required to process the complex mode decision calculation, yet suffering a long coding time. To overcome the problem, this paper proposes a fast direct mode prediction algorithm. Simulation results show that the proposed algorithm can determine the direct mode coding without a complex mode decision process for 42% more macroblocks and, this algorithm can reduce coding time by up to 23%, compared with Jin's algorithm. This enables to encode B frames fast with a less quality degradation.

A Research on the PIV Algorithm Using Image Coding (영상코드화 기법을 이용한 PIV 알고리듬에 대한 연구)

  • Kim, Sung-Kyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • 제24권2호
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    • pp.153-160
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    • 2000
  • A Particle Image Velocimetry(PIV) algorithm is developed to analyze whole flow field both qualitatively and quantitatively. The practical use of PIV requires the use of fast, reliable, computer-based methods for tracking numerous particles suspended in a flow field. The TSS, NTSS, FFT-Hybrid, which are developed in the area of image compression and coding, are introduced to develop fast vector search algorithm. The numerical solution of the lid-driven cavity flow by the ADI algorithm with the Wachspress Formula is introduced to produce synthetic data for the validation of the tracking algorithms. The algorithms are applied to image data of real flow experiments. The comparisons in CPU time and mean error show, with a small loss of accuracy, CPU time for tracking is reduced considerably.

Constrained Sparse Concept Coding algorithm with application to image representation

  • Shu, Zhenqiu;Zhao, Chunxia;Huang, Pu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권9호
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    • pp.3211-3230
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    • 2014
  • Recently, sparse coding has achieved remarkable success in image representation tasks. In practice, the performance of clustering can be significantly improved if limited label information is incorporated into sparse coding. To this end, in this paper, a novel semi-supervised algorithm, called constrained sparse concept coding (CSCC), is proposed for image representation. CSCC considers limited label information into graph embedding as additional hard constraints, and hence obtains embedding results that are consistent with label information and manifold structure information of the original data. Therefore, CSCC can provide a sparse representation which explicitly utilizes the prior knowledge of the data to improve the discriminative power in clustering. Besides, a kernelized version of our proposed CSCC, namely kernel constrained sparse concept coding (KCSCC), is developed to deal with nonlinear data, which leads to more effective clustering performance. The experimental evaluations on the MNIST, PIE and Yale image sets show the effectiveness of our proposed algorithms.

Idol Fan's Acceptance Process of Idol Image -Focusing on BTS- (아이돌 팬의 아이돌 이미지 수용 과정 -BTS를 중심으로-)

  • Yi, Jia;Suh, Seunghee
    • Journal of Fashion Business
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    • 제26권3호
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    • pp.98-115
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    • 2022
  • The purpose of study was to analyze the process of accepting by BTS fans. The methodology used in this study was qualitative research using grounded theory and the results of the study follow. As a result of open coding, 47 concepts, 23 subcategories, and 14 categories were derived. In the axis coding stage, the casual conditions were "Recognition of BTS image," "Fascinated by BTS image," "Simple consumption of BTS image," and "Arising and expansion of curiosity about BTS image." The contextual conditions were "Accessibility of BTS image" and "Abundance of BTS image searching paths." The central phenomenon appeared to be "Immersing and studying BTS image." The arbitration conditions were "Capabilities required to reproduce BTS image" and "Motivation for contributing BTS image." The actions/interactions were "Presenting BTS image," "Contribution to the spread of BTS image," and "Involved in forming new BTS image." The result was "Emergence and expansion of new BTS image meaning" and "Strengthening attachment to BTS." Through process analysis, it was found that acceptance of BTS images consisted of five stages: "Recognition of BTS image," "Becoming curious about BTS image," "Searching BTS image," "Intervention of BTS image." and "Reproduction of BTS image." As a result of deriving the core categories through selective coding, the core category was "Forming a bond while participating in the BTS image."

A New Image Compression Technique for Multimedia Teleconferences (멀티미디어 텔레컨퍼런스를 위한 새로운 영상 압축 기술)

  • Kim, Yong-Ho;Chang, Jong-Hwan
    • The Journal of Natural Sciences
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    • 제5권2호
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    • pp.33-38
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    • 1992
  • A new texture segmentation-based image coding technique which performs segmentation based on roughness of textural regions and properties of the human visual system (HVS) is presented for multime-dia teleconference. The segmentation is accomplished by thresholding the fractal dimension so that textural regions are classified into three texture classes; perceived constant intensity, smooth texture, and rough texture. An image coding system with high compression and good image quality is achieved by developing an efficient coding technique for each segment boundary and each texture class. We compare the coding efficiency of this technique with that of a well established technique (discrete cosine transform (DCT) image coding).

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