• Title/Summary/Keyword: color image coding

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The YIQ Model of Computed Tomography Color Image Variable Block with Fractal Image Coding (전산화단층촬영 칼라영상의 YIQ모델을 가변블록 이용한 프랙탈 영상 부호화)

  • Park, Jae-Hong;Park, Cheol-Woo
    • Journal of the Korean Society of Radiology
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    • v.10 no.4
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    • pp.263-270
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    • 2016
  • This paper suggests techniques to enhance coding time which is a problem in traditional fractal compression and to improve fidelity of reconstructed images by determining fractal coefficient through adaptive selection of block approximation formula. First, to reduce coding time, we construct a linear list of domain blocks of which characteristics is given by their luminance and variance and then we control block searching time according to the first permissible threshold value. Next, when employing three-level block partition, if a range block of minimum partition level cannot find a domain block which has a satisfying approximation error, There applied to 24-bpp color image compression and image techniques. The result did not occur a loss in the image quality of the image when using the encoding method, such as almost to the color in the YIQ image compression rate and image quality, such as RGB images and showed good.

Color Image Coding using Variable Block of Fractal (프랙탈 기반의 가변블록을 이용한 컬러영상 부호화)

  • Park, Jae-Hong;Park, Cheol-Woo
    • Journal of the Korean Society of Radiology
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    • v.8 no.7
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    • pp.435-441
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    • 2014
  • This paper suggests techniques to enhance coding time which is a problem in traditional fractal compression and to improve fidelity of reconstructed images by determining fractal coefficient through adaptive selection of block approximation formula. First, to reduce coding time, we construct a linear list of domain blocks of which characteristics is given by their luminance and variance and then we control block searching time according to the first permissible threshold value. Next, when employing three-level block partition, if a range block of minimum partition level cannot find a domain block which has a satisfying approximation error, There applied to 24-bpp color image compression and image techniques. The result did not occur a loss in the image quality of the image when using the encoding method, such as almost to the color in the RGB image compression rate and image quality, such as gray-level images and showed good.

H.264 Encoding Technique of Multi-view Image expressed by Layered Depth Image (계층적 깊이 영상으로 표현된 다시점 영상에 대한 H.264 부호화 기술)

  • Kim, Min-Tae;Jee, Inn-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.1
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    • pp.81-90
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    • 2010
  • This paper presents H.264 coding schemes for multi-view video using the concept of layered depth image(LDI) representation and efficient compression technique for LDI. After converting those data to the proposed representation, we encode color, depth, and auxiliary data representing the hierarchical structure, respectively, Two kinds of preprocessing approaches are proposed for multiple color and depth components. In order to compress auxiliary data, we have employed a near lossless coding method. Finally, we have reconstructed the original viewpoints successfully from the decoded approach that is useful for dealing with multiple color and depth data simultaneously.

Software development for the visualization of brain fiber tract by using 24-bit color coding in diffusion tensor image

  • Oh, Jung-Su;Song, In-Chan;Ik hwan Cho;Kim, Jong-Hyo;Chang, Kee-Hyun;Park, Kwang-Suk
    • Proceedings of the KSMRM Conference
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    • 2002.11a
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    • pp.133-133
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    • 2002
  • Purpose: The purpose of paper is to implement software to visualize brain fiber tract using a 24-bit color coding scheme and to test its feasibility. Materials and Methods: MR imaging was performed on GE 1.5 T Signa scanner. For diffusion tensor image, we used a single shot spin-echo EPI sequence with 7 non-colinear pulsed-field gradient directions: (x, y, z):(1,1,0),(-1,1,0),(1,0,1),(-1,0,1),(0,1,1),(0,1,-1) and without diffusion gradient. B-factor was 500 sec/$\textrm{mm}^2$. Acquisition parameters are as follows: TUTE=10000ms/99ms, FOV=240mm, matrix=128${\times}$128, slice thickness/gap=6mm/0mm, total slice number=30. Subjects consisted of 10 normal young volunteers (age:21∼26 yrs, 5 men, 5 women). All DTI images were smoothed with Gaussian kernel with the FWHM of 2 pixels. Color coding schemes for visualization of directional information was as follows. HSV(Hue, Saturation, Value) color system is appropriate for assigning RGB(Red, Green, and Blue) value for every different directions because of its volumetric directional expression. Each of HSV are assigned due to (r,$\theta$,${\Phi}$) in spherical coordinate. HSV calculated by this way can be transformed into RGB color system by general HSV to RGB conversion formula. Symmetry schemes: It is natural to code the antipodal direction to be same color(antipodal symmetry). So even with no symmetry scheme, the antipodal symmetry must be included. With no symmetry scheme, we can assign every different colors for every different orientation.(H =${\Phi}$, S=2$\theta$/$\pi$, V=λw, where λw is anisotropy). But that may assign very discontinuous color even between adjacent yokels. On the other hand, Full symmetry or absolute value scheme includes symmetry for 180$^{\circ}$ rotation about xy-plane of color coordinate (rotational symmetry) and for both hemisphere (mirror symmetry). In absolute value scheme, each of RGB value can be expressed as follows. R=λw|Vx|, G=λw|Vy|, B=λw|Vz|, where (Vx, Vy, Vz) is eigenvector corresponding to the largest eigenvalue of diffusion tensor. With applying full symmetry or absolute value scheme, we can get more continuous color coding at the expense of coding same color for symmetric direction. For better visualization of fiber tract directions, Gamma and brightness correction had done. All of these implementations were done on the IDL 5.4 platform.

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A block-based face detection algorithm for the efficient video coding of a videophone (효율적인 화상회의 동영상 압축을 위한 블록기반 얼굴 검출 방식)

  • Kim, Ki-Ju;Bang, Kyoung-Gu;Moon, Jeong-Mee;Kim, Jae-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.9C
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    • pp.1258-1268
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    • 2004
  • We propose a new fast, algorithm which is used for detecting frontal face in the frequency domain based on human skin-color using OCT coefficient of dynamic image compression and skin color information. The region where each pixel has a value of skin-color were extracted from U and V value based on DCT coefficient obtained in the process of Image compression using skin-color map in the Y, U, V color space A morphological filter and labeling method are used to eliminate noise in the resulting image We propose the algorithm to detect fastly human face that estimate the directional feature and variance of luminance block of human skin-color Then Extraction of face was completed adaptively on both background have the object analogous to skin-color and background is simple in the proposed algorithm The performance of face detection algorithm is illustrated by some simulation results earned out on various races We confined that a success rate of 94 % was achieved from the experimental results.

Adaptive Rank-reindexing Scheme for Index Image Lossless Compression (인덱스 영상에서의 무손실 압축을 위한 적응적 랭크-리인덱싱 기법)

  • Park, Jung-Man;You, Kang-Soo;Jang, Euee-S.;Kwak, Hoon-Sung
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.164-166
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    • 2005
  • In this paper, using ranks of co-occurrence frequency about indices in neighboring pixels, we introduce a new re-indexing scheme for efficiency of index color image lossless compression. The proposed method is suitable for arithmetic coding because it has skewed distributions of small variance. Experimental results proved that the proposed method reduces the bit rates than other coding schemes, more specifically 15%, 54% and 12% for LZW algorithm of GIF, the plain arithmetic coding method and Zeng's scheme.

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An Effcient Lossless Compression Algorithm using Arithmetic Coding for Indexed Color lmage (산술부호화를 이용한 인덱스 칼라 이미지에서의 효율적인 무손실 압축 방법)

  • You Kang-Soo;Lee Han-Jeong;Jang Euee S.;Kwak Hoon-Sung
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.1C
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    • pp.35-43
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    • 2005
  • This paper introduces a new algorithm to improve compression performance of 256 color images called palette-based or indexed images. The proposed scheme counts each frequency of index values after present index value and determines each rank for every index value by sorting them in descending order. Then, the scheme makes ranked index image instead of original indexed image using the way to replace index values with ranks. In the ranked index image's distribution produced as a result of this algorithm, the higher ranked index value, the more present same values. Therefore, data redundancy will be raised and more efficient performance of compression can be expected. Simulation results verify that because of higher compression ratio by up to 22.5, this newly designed algorithm shows a much better performance of compression in comparison with the arithmetic coding, intensity-based JPEG-LS and palette-based GIF.

Adaptive Rank-Reindexing Algorithm for Lossless Index Image Compression (무손실 인덱스 영상 압축을 위한 적응적 랭크-리인덱싱 알고리즘)

  • Lee Han-Jeong;Yoo Gi-Hyung;Kim Hyung-Moo;You Kang-Soo;Kwak Hoon-Sung
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.8
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    • pp.501-503
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    • 2005
  • In this paper, using ranks of co-occurrence frequency about indices in pairs of neighboring pixels, we introduce a new re-indexing algorithm for efficiency of index color image lossless compression. The proposed algorithm is suitable for arithmetic coding because it has concentrated distributions of small variance. Experimental results proved that the proposed algorithm reduces the bit rates than other coding schemes, more specifically $15\%$, $54\%$ and $12\%$ for LZW algorithm of GIF, the plain arithmetic coding method and Zeng's scheme, respectively.

A New Proposal of Adaptive BTC for Image Data Compression (畵像壓縮을 위한 適應 BTC 方法의 提案)

  • Jang, Ki-Soong;Oh, Seong-Mock;Lee, Young-Choul
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.7
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    • pp.125-131
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    • 1989
  • This paper proposes a new ABTC (Adaptive Block Truncation Coding) algorithm which improves the BTC algorithm for image data compression. A new adaptive block truncation coding which adopts a selective coding scheme depending on the local characteristics of an image has been described. The characteristics of the ABTC algorithm can be summarized as high compression ratio and the algorithm simplicity. Using this algorithm, color images can be coded at a variable bit rate from 1.0 (bit/pel) to 2.56 (bit/pel) and high compression rate (1.3-105 bit/pel) can be achieved without conspicuous image degradation compared with original images.

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Depth compression method for 3D video (3차원 영상을 위한 깊이 영상 압축 방법)

  • Nam, Jung-Hak;Hwang, Neung-Joo;Cho, Gwang-Shin;Sim, Dong-Gyu;Lee, Soo-Youn;Bang, Gun;Hur, Nam-Ho
    • Journal of Broadcast Engineering
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    • v.15 no.5
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    • pp.703-706
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    • 2010
  • Recently, a need to encode a depth image has been raising with the deployment of 3D video services. The 3DV/FTV group in the MPEG has standardized the compression method of depth map image. Because conventional depth map coding methods are independently encoded without referencing the color image, coding performance of conventional algorithms is poor. In this letter, we proposed a novel method which rearranged modes of depth blocks according to modes of corresponding color blocks by using a correlation between color and depth images. In experimental results, the proposed method achieves bits reduction of 2.2% compared with coding method based on JSVM.