• Title/Summary/Keyword: Compression format

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A Reversible Data Hiding Method for AMBTC Compressed Image without Expansion inside Stego Format

  • Hui, Zheng;Zhou, Quan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.11
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    • pp.4443-4462
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    • 2020
  • This paper proposes a new framework of reversible data hiding scheme for absolute moment truncation coding (AMBTC) compressed images. AMBTC-based RDH can be applied to optical remote sensing (ORS) image transmission, which achieves target region preservation and image compression simultaneously. Existing methods can be concluded as two types. In type I schemes, stego codes mimic the original AMBTC format where no file bloat occurs, yet the carried secret data is limited. Type II schemes utilize predication errors to recode quantity levels of AMBTC codes which achieves significant increase in embedding capacity. However, such recoding causes bloat inside stego format, which is not appropriate in mentioned ORS transmission. The proposed method is a novel type I RDH method which prevents bloat inside AMBTC stego codes with significant improvement in embedding capacity. The AMBTC compressed trios are grouped into two categories according to a given threshold. In smooth trio, the modified low quantity level is constructed by concatenating Huffman codes and secret bits. The reversible contrast mapping (RCM) is performed to complex trios for data embedment. Experiments show that the proposed scheme provides highest payload compared with existing type I methods. Meanwhile, no expansion inside stego codes is caused.

All-Optical Bit-Rate Flexible NRZ-to-RZ Conversion Using an SOA-Loop Mirror and a CW Holding Beam

  • Lee, Hyuek Jae
    • Journal of the Optical Society of Korea
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    • v.20 no.4
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    • pp.464-469
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    • 2016
  • All-optical non-return-to-zero (NRZ) -to- return-to-zero (RZ) data-format conversion has been successfully demonstrated using a semiconductor optical amplifier in a fiber-loop mirror (so-called SOA-loop mirror) with a continuous-wave (CW) holding beam. The converted RZ signal after pulse compression has been used to create a 40 Gb/s OTDM (Optical Time Division Multiplexing) signal. Here is proposed an NRZ-to-RZ conversion method without any additional optical clocks, unlike conventional methods based on optical AND logic. In addition, it has the merit of operating at various bit-rate speeds without any controlling device. Moreover, it has a simple structure, and it can be used for all-optical bit-rate-flexible clock recovery.

An Efficient Representation of Edge Shapes in Topological Maps

  • Doh, Nakju Lett;Chung, Wan-Kyun
    • ETRI Journal
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    • v.29 no.5
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    • pp.655-666
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    • 2007
  • There are nodes and edges in a topological map. Node data has been used as a main source of information for the localization of mobile robots. In contrast, edge data is regarded as a minor source of information, and it has been used in an intuitive and heuristic way. However, edge data also can be used as a good source of information and provide a way to use edge data efficiently. For that purpose, we define a data format which describes the shape of an edge. This format is called local generalized Voronoi graph's angle (LGA). However, the LGA is constituted of too many samples; therefore, real time localization cannot be performed. To reduce the number of samples, we propose a compression method which utilizes wavelet transformation. This method abstracts the LGA by key factors using far fewer samples than the LGA. Experiments show that the LGA accurately describes the shape of the edges and that the key factors preserve most information of the LGA while reducing the number of samples.

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Selection and Design of Functional Area of Compression Garment for Improvement in Knee Protection (무릎 안전성 향상을 위한 컴프레션 의복의 기능적 디자인 영역 선정과 설계법)

  • Lee, Hyo Jeong;Kim, Nam Yim;Hong, Kyung Hi;Lee, Ye Jin
    • Korean Journal of Human Ecology
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    • v.24 no.1
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    • pp.97-109
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    • 2015
  • Recently, because the market for compression wear now includes all consumers, not just professionals, various items for recovery after exercising or for enhanced effects from exercise have been introduced. In this research, a systematic and stepwise design process was proposed to develop compression garment that has both functional area and appropriate pressure to protect the knee when exercising. The U-V format functional area that wraps underneath the knee was selected by considering the shape and change in the skin length when bending the knee. After the selection of the functional area, a total of seven knee design areas, including the existing product, were designed to determine the appropriate pressure. After various movements, the compression garment was ranked in terms of support of the knee, level of pressure, discomfort of seam line, and comfort of popliteal; the preferred design was selected using the quad method. Four compression wear garments were produced using two selected preferred designs; the wear evaluation was performed using a seven-point Likert scale. As a result, the optimal reduction rate of the pattern was calculated based on Ziegert and Keil's method. The applied percentage of the fabric stretch at the upper part of the crotch was 66% for the width and 50% for the length; for the lower part of the crotch, only 66% for the width was applied. Moreover, it was determined that the design of the U-V knee protection part was preferred when a 7 mm square was placed at a 1 mm distance because this not only supports the knee but also allows the fabric to accommodate various skin deformations.

Approximate-SAD Circuit for Power-efficient H.264 Video Encoding under Maintaining Output Quality and Compression Efficiency

  • Le, Dinh Trang Dang;Nguyen, Thi My Kieu;Chang, Ik Joon;Kim, Jinsang
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.5
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    • pp.605-614
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    • 2016
  • We develop a novel SAD circuit for power-efficient H.264 encoding, namely a-SAD. Here, some highest-order MSB's are approximated to single MSB. Our theoretical estimations show that our proposed design simultaneously improves performance and power of SAD circuit, achieving good power efficiency. We decide that the optimal number of approximated MSB's is four under 8-bit YUV-420 format, the largest number not to affect video quality and compression-rate in our video experiments. In logic simulations, our a-SAD circuit shows at least 9.3% smaller critical-path delay compared to existing SAD circuits. We compare power dissipation under iso-throughput scenario, where our a-SAD circuit obtains at least 11.6% power saving compared to other designs. We perform same simulations under two- and three-stage pipelined architecture. Here, our a-SAD circuit delivers significant performance (by 13%) and power (by 17% and 15.8% for two and three stages respectively) improvements.

Control of IEEE1394 digital home appliances using AV/C Command Set

  • Kim, Il-Jung;Park, Jong-An
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.98.2-98
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    • 2001
  • It is necessary to have enough transmission capacity for advanced internet techniques and various digital home appliances networking. Home appliances interface IEEE1394 technique has much wealthy transmission skill. IEEE1394 is using home appliances through various information form image and voice change data real time print out. In this paper, AVC CTS technology and IEEE1394 technology are introduced. Digital Video Camera includes compression format using DV. System composition control is consisted of protocols like IEC-61883 and AV/C command set standard.

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A Study on the Development of a MPACS (시범 MPAC 시스템 개발에 관한 연구)

  • 김근섭;임호근
    • Journal of Biomedical Engineering Research
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    • v.12 no.3
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    • pp.215-222
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    • 1991
  • In this paper, we present a result of our study on how to construct a pilot MPACS (medical hic lure archiving and communication System) based on X -Window system. The proposed MPACS Is composed of image acquisition units, image archiving and processing units, display units, and all units are Interfaced with a LAN The image management is done according to the TIFF (Tagged Image File Format) , and the dis- play system is built upon generally accepted software packages, namely the X -Window system. Also, lossless and lossy digital image compression methods were implemented and tested with X -ray and CT images.

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Processing Method of Mass Small File Using Hadoop Platform (하둡 플랫폼을 이용한 대량의 스몰파일 처리방법)

  • Kim, Chang-Bok;Chung, Jae-Pil
    • Journal of Advanced Navigation Technology
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    • v.18 no.4
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    • pp.401-408
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    • 2014
  • Hadoop is composed with MapReduce programming model for distributed processing and HDFS distributed file system. Hadoop is suitable framework for big data processing, but processing of mass small files have many problems. The processing of mass small file in hadoop have problems to created one mapper per one file, and it have problems to needed many memory for store of meta information of file. This paper have comparison evaluation processing method of mass small file with various method in hadoop platform. The processing of general compression format is inadequate because of processing by one mapper regardless of data size. The processing of sequence and hadoop archive file is removed memory problem of namenode by compress and combine of small file. Hadoop archive file is faster then sequence file about combine time of small file. The processing using CombineFileInputFormat class is needed not combine of small file, and it have similar speed big data processing method.

A Method of Recovery for Damaged ZIP Files (손상된 ZIP 파일 복구 기법)

  • Jung, Byungjoon;Han, Jaehyeok;Lee, Sang-jin
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.27 no.5
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    • pp.1107-1115
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    • 2017
  • The most commonly used PKZIP format is a ZIP file, as well as a file format used in MS Office files and application files for Android smartphones. PKZIP format files, which are widely used in various areas, require structural analysis from the viewpoint of digital forensics and should be able to recover when files are damaged. However, previous studies have focused only on recovering data or extracting meaningful data using the Deflate compression algorithm used in ZIP files. Although most of the data resides in compressed data in the ZIP file, there is also forensically meaningful data in the rest of the ZIP file, so you need to restore it to a normal ZIP file format. Therefore, this paper presents a technique to recover a damaged ZIP file to a normal ZIP file when given.

A Digital Watermarking Technique for MPEG Image/Video Compression (MPEG 영상/비디오 압축을 위한 디지털 워터마킹 기법)

  • Yoo Byoung-Seok;Choi Hyun-Jun;Seo Young-Ho;Kim Dong-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.5C
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    • pp.406-414
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    • 2005
  • The necessity for a technique to protect intellectual property of a digital content has been increasing, especially for the image/video contents which are the most favorite because of their high information-intensive property. According to this demand, this paper proposed a digital watermarking algorithm, which is recognized as the most promising technique. This algorithm targets MPEG compression system and the watermarking process is to be performed during the compression process. It inserts watermark only in Y components of I-frames. Experimental results showed that the proposed method satisfied both imperceptibility and robustness against various attacks. The PSNR difference between the compressed images(the average compression ratio was about 27:1 with Y:Cb:Cr=4:2:0 color format for TM5-based compression) with and without watermarking was only 1.8dB ($4.2\%$). In each case that the resulting image after an attack was reusable the normalized correlation between the extracted watermark and the original one was above 0.8.