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      • Lossless Image Compression Using Differential Pulse Code Modulation and Its Application

        Rime Raj Singh Tomar,Kapil Jain 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.1

        Images include information about human body which is used for different purpose such as medical examination security and other plans Compression of images is used in some applications such as profiling information and transmission systems. Regard to importance of images information, lossless or loss compression is preferred. Lossless compressions are JPEG, JPEG-LS and JPEG2000 are few well-known methods for lossless compression. We will use differential pulse code modulation for image compression with Huffman encoder, which is one of the latest and provides good compression ratio, peak signal to noise ratio and minimum mean square error. In real time application which needs hardware implementation, low complex algorithm accelerate compression process. In this paper, we use differential pulse code modulation for image compression lossless and near-lossless compression method is introduced which is efficient due to its high compression ratio and simplicity. This method is consists of a new transformation method called Enhanced DPCM Transformation (EDT) which has a good energy compaction and a suitable Huffman encoding. After introducing this compression method it is applied on different images from Corel dataset for experimental results and analysis. Also we compare it with other existing methods with respect to parameter compression ratio, peak signal noise ratio and mean square error.

      • KCI등재후보

        영역 성장 분할 기법을 이용한 무손실 영상 압축

        박정선,김길중,전계록 한국융합신호처리학회 2002 융합신호처리학회 논문지 (JISPS) Vol.3 No.1

        본 연구에서는 의료영상 저장 및 전송 시스템에 필수적인 무손실 의료영상 압축 기법을 제안하였다. 의료영상은 방사선 영상 중에서 유방영상(mammography)과 자기공명영상을 사용하였으며, 이들 영상을 무손실로 압축하기 위하여 영역성장에 의한 영상분할 알고리듬을 제안하였다. 제안된 알고리듬은 원 영상이 에러 영상과 불연속 계수 영상, 그리고 상위 비트 데이터 등 세 가지의 부 영역으로 분할되도록 하였다. 그리고 영역성장 과정 후 생성된 불연속 계수 영상 데이터와 에러 영상을 국제 이진영상압축 표준이며 그레이코드(graycode)화된 영상의 압축에 적합한 JBIG(Joint Bi-level Image expert Group) 알고리듬을 이용하여 압축시켰다. 제안한 알고리듬과 타 연구에서 사용된 기법들을 비교 검토 한 결과 제안한 무손실 압축 기법을 적용하여 얻어지는 압축율은 JBIG, JPEG, LZ 기법에 비해 평균적으로 각각 3.7%, 7.9%, 23.6% 정도 개선됨을 알 수 있었다. In this paper, we proposed a lossless compression algorithm of medical images which is essential technique in picture archive and communication system. Mammographic image and magnetic resonance image in among medical images used in this study, proposed a region growing segmentation algorithm for compression of these images. A proposed algorithm was partition by three sub region which error image, discontinuity index map, high order bit data from original image. And generated discontinuity index image data and error image which apply to a region growing algorithm are compressed using JBIG(Joint Bi-level Image experts Group) algorithm that is international hi-level image compression standard and proper image compression technique of gray code digital Images. The proposed lossless compression method resulted in, on the average, lossless compression to about 73.14% with a database of high-resolution digital mammography images. In comparison with direct coding by JBIG, JPEG, and Lempel-Ziv coding methods, the proposed method performed better by 3.7%, 7.9% and 23.6% on the database used.

      • KCI등재

        An Efficient Bit-Level Lossless Grayscale Image Compression Based on Adaptive Source Mapping

        ( Ayman Al Dmour ),( Mohammed Abuhelaleh ),( Ahmed Musa ),( Hasan Al Shalabi ) 한국정보처리학회 2016 Journal of information processing systems Vol.12 No.2

        Image compression is an essential technique for saving time and storage space for the gigantic amount of data generated by images. This paper introduces an adaptive source-mapping scheme that greatly improves bitlevel lossless grayscale image compression. In the proposed mapping scheme, the frequency of occurrence of each symbol in the original image is computed. According to their corresponding frequencies, these symbols are sorted in descending order. Based on this order, each symbol is replaced by an 8-bit weighted fixed-length code. This replacement will generate an equivalent binary source with an increased length of successive identical symbols (0s or 1s). Different experiments using Lempel-Ziv lossless image compression algorithms have been conducted on the generated binary source. Results show that the newly proposed mapping scheme achieves some dramatic improvements in regards to compression ratios.

      • KCI등재

        블록 적응적인 Context Tree Weighting을 이용한 무손실 영상 압축

        오은주,조현지,유훈 한국인터넷정보학회 2020 인터넷정보학회논문지 Vol.21 No.4

        This paper proposes a lossless image compression method based on arithmetic coding using block-adaptive Context Tree Weighting. The CTW method predicts and compresses the input data bit by bit. Also, it can achieve a desirable coding distribution for tree sources with an unknown model and unknown parameters. This paper suggests the method to enhance the compression rate about image data, especially aerial and satellite images that require lossless compression. The value of aerial and satellite images is significant. Also, the size of their images is huger than common images. But, existed methods have difficulties to compress these data. For these reasons, this paper shows the experiment to prove a higher compression rate when using the CTW method with divided images than when using the same method with non-divided images. The experimental results indicate that the proposed method is more effective when compressing the divided images. 본 논문은 입력 영상 데이터를 블록 적응적으로 Context Tree Weighting을 사용하여 산술 부호 기반의 무손실 영상 압축 방법을제안한다. CTW 기법은 입력 데이터를 비트 단위로 예측 및 압축을 하는 특성을 가진다. 또한, CTW 기법은 미지의 모델 및 파라미터에 대해서도 효율적인 압축을 한다는 점에서 장점을 보여준다. 본 연구에서는 무손실 압축이 필요한 항공 및 위성 사진을 옵션 정보에 따라 분할한 다음 각각 CTW 기반의 산술 부호기를 적용하여 압축의 효율을 증대하고자 한다. 항공 및 위성 사진은 영상 내 정보의 가치가 높으므로 무손실 압축이 불가피하다. 또한, 영상 크기가 일반적인 영상에 비해 크기 때문에 고압축 역시 필요하다. 기존의무손실 압축 기법으로는 대용량의 중요 영상을 압축하는 데에 어려움이 존재한다. 이러한 이유로, 본 논문에서는 분할하지 않은 영상을 압축할 때 보다 제안하는 방법을 통해 영상을 압축했을 때 더 높은 압축률을 보여주기 위한 실험을 제공한다. 실험을 통해 기존의무손실 압축 기법을 사용하여 압축을 진행했을 때 보다 CTW 기법을 이용하여 분할한 영상을 압축했을 때의 압축률이 더 높음을 확인할 수 있다.

      • KCI등재

        산술부호화를 이용한 인덱스 칼라 이미지에서의 효율적인 무손실 압축 방법

        유강수,이한정,장의선,곽훈성,You Kang-Soo,Lee Han-Jeong,Jang Euee S.,Kwak Hoon-Sung 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.1C

        본 논문에서는 팔레트 기반 이미지(palette-based image) 또는 인덱스 이미지(indexed image)라고 불리는 256색의 이미지에 대한 압축 성능 향상을 위한 새로운 알고리즘을 소개한다. 제안한 방식은 현재 색상이 갖는 인덱스 값을 중심으로 다음에 나오는 색상의 인덱스가 얼마나 발생하는지를 측정하고, 발생 빈도를 정렬하여 순위를 구한 후에, 색상에 대한 인덱스 값을 순위로 표현하여 원래의 인덱스 이미지를 대체한다. 그렇게 변화된 순위 인덱스이미지(ranked index image)의 인덱스 분포에서는 순위가 높은 곳에 같은 인덱스들이 더 많이 존재하기 때문에 데이터 중복성(redundancy)을 높일 수 있어, 압축 효율을 기대할 수 있다. 실험 결과에서는, 기존의 산술부호화 방식, 휘도 성분 기반의 JPEG-LS 방식 그리고 인덱스 기반의 GIF 방식들과 비교할 때, 원 이미지에 대한 압축률이 최대 22.5까지 향상되어 제안한 방식의 압축 성능이 훨씬 뛰어나다는 것을 보여준다. 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.

      • KCI등재후보

        3차원 정수 웨이브릿 변환과 리프팅 스텝을 이용한 3차원 무 손실 의료 영상 압축 방법에 대한 연구

        김영섭 대한의료정보학회 2004 Healthcare Informatics Research Vol.10 No.1

        This paper focuses on lossless medical image compression methods for medical images that operate on three-dimensional(3-D) irreversible integer wavelet transform. We offer an application of the Set Partitioning in Hierarchical Trees(SPIHT) algorithm to medical images, using a 3-D wavelet decomposition and a 3-D spatial dependence tree. The wavelet decomposition is accomplished with integer wavelet filters implemented with the lifting method, where careful scaling( 2) and truncations keep the integer precision and the transform unitary. We have tested our encoder on volumetric medical images using different integer filters and different 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. Results show that, even with these small coding units, our algorithm with certain filters performs as well and better in lossless coding than previous coding systems using 3-D integer wavelet transforms on volumetric medical images.

      • KCI등재

        인덱스 이미지에서의 무손실 압축을 위한 적응적 순위 기반 재인덱싱 기법

        유강수,이봉주,장의선,곽훈성,You Kang-Soo,Lee Bong-Ju,Jang Euee S.,Kwak Hoon-Sung 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.7C

        인덱스 이미지를 구성하는 요소들을 재구성하는 기법을 재인덱싱이라 한다. 이는 무손실 압축의 효율을 높이기 위한 방법으로 잘 알려져 있다. 본 논문에서는 이웃하는 픽셀간의 발생빈도수에 대한 순위를 가지고 재인덱싱 기법을 보다 유연하게 처리하기 위한 적응적 방법을 소개한다. 제안한 방법을 통하여 획득한 순위로 구성된 이미지를 산술 부호화하여 무손실 압축을 행한다. 이때 발생하는 순위 정보를 송신측으로 보내지 않게 하기 위해 적응적으로 한 픽셀씩 처리한다. 순위 정보로 전환된 이미지를 순위 이미지라고 부른다. 이러한 순위 이미지는 동일한 순위에 포함되는 많은 픽셀들이 존재하게 되어 일반적인 이미지보다 데이터의 중복성을 높일 수 있고 데이터 분포가 한쪽으로 편중되어 있어 산술 부호화의 효율을 기대할 수 있다. 실험 결과, 제안한 적응적 순위 기반 재인덱싱 방법은 Zeng의 방법보다 최대 26$\%$의 비트율 절감 효과를 보였다. Re-assignment scheme of index in index image is called reindexing. It has been well known that index image can be reindexed without losslessness. In this paper, we introduces an adaptive rank based reindexing scheme using co-occurrence frequency between neighboring pixels. Original index image can be converted into rank image by the proposed scheme. Using the proposed scheme, a better compression efficiency can be expected because most of the reindexed values(rank) get distributed with a smaller variance than the original index image. Experinental results show that the proposed scheme achieves a much better compression performance over GIF, arithmetic coding, Zeng's algorithm and RIAC scheme.

      • SIMPLE BIT-PLANE CODING CONDITIONED BY EXPECTATION VALUES OF PIXELS FOR LOSSY-TO-LOSSLESS IMAGE COMPRESSION

        Hisakazu Kikuchi,Shogo Muramatsu 대한전자공학회 2009 ITC-CSCC :International Technical Conference on Ci Vol.2009 No.7

        A lossless image compression is presented as a bit-plane coding that exploits a scheme of bit modeling by the expectation values of pixel values at a decoder. The algorithm is simple and various functionality extensions are implemented including selective tile partitioning, progressive transmission, ROI transmission, accuracy scalability, and others. The mean squared error between the original image and a decoded image at any progression level is known prior to encoding. The proposed bit-plane codec is competitive with JPEG-LS and JPEG 2000 in the lossless compression of 8-bit grayscale and 24-bit color images.

      • KCI등재

        Lossless Compression for Hyperspectral Images based on Adaptive Band Selection and Adaptive Predictor Selection

        ( Fuquan Zhu ),( Huajun Wang ),( Liping Yang ),( Changguo Li ),( Sen Wang ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.8

        With the wide application of hyperspectral images, it becomes more and more important to compress hyperspectral images. Conventional recursive least squares (CRLS) algorithm has great potentiality in lossless compression for hyperspectral images. The prediction accuracy of CRLS is closely related to the correlations between the reference bands and the current band, and the similarity between pixels in prediction context. According to this characteristic, we present an improved CRLS with adaptive band selection and adaptive predictor selection (CRLS-ABS-APS). Firstly, a spectral vector correlation coefficient-based k-means clustering algorithm is employed to generate clustering map. Afterwards, an adaptive band selection strategy based on inter-spectral correlation coefficient is adopted to select the reference bands for each band. Then, an adaptive predictor selection strategy based on clustering map is adopted to select the optimal CRLS predictor for each pixel. In addition, a double snake scan mode is used to further improve the similarity of prediction context, and a recursive average estimation method is used to accelerate the local average calculation. Finally, the prediction residuals are entropy encoded by arithmetic encoder. Experiments on the Airborne Visible Infrared Imaging Spectrometer (AVIRIS) 2006 data set show that the CRLS-ABS-APS achieves average bit rates of 3.28 bpp, 5.55 bpp and 2.39 bpp on the three subsets, respectively. The results indicate that the CRLS-ABS-APS effectively improves the compression effect with lower computation complexity, and outperforms to the current state-of-the-art methods.

      • SCOPUSKCI등재

        An Efficient Bit-Level Lossless Grayscale Image Compression Based on Adaptive Source Mapping

        Al-Dmour, Ayman,Abuhelaleh, Mohammed,Musa, Ahmed,Al-Shalabi, Hasan Korea Information Processing Society 2016 Journal of information processing systems Vol.12 No.2

        Image compression is an essential technique for saving time and storage space for the gigantic amount of data generated by images. This paper introduces an adaptive source-mapping scheme that greatly improves bit-level lossless grayscale image compression. In the proposed mapping scheme, the frequency of occurrence of each symbol in the original image is computed. According to their corresponding frequencies, these symbols are sorted in descending order. Based on this order, each symbol is replaced by an 8-bit weighted fixed-length code. This replacement will generate an equivalent binary source with an increased length of successive identical symbols (0s or 1s). Different experiments using Lempel-Ziv lossless image compression algorithms have been conducted on the generated binary source. Results show that the newly proposed mapping scheme achieves some dramatic improvements in regards to compression ratios.

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