• Title/Summary/Keyword: memory compression

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Tiled Image Compression Method to Reduce the Amount of Memory Needed for Image Processing in Mobile Devices (모바일 단말기에서 이미지 처리에 필요한 메모리 사용량을 줄이기 위한 타일화 이미지 압축 기법)

  • Oh, Hwang-Seok
    • Journal of Korea Game Society
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    • v.13 no.6
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    • pp.35-42
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    • 2013
  • A new compressed image format is proposed to use a large size of image in mobile games without the constraints of hardware specifications such as memory amount, processing power, which encodes each block of a large size image in scan line order. Using the experiments, we show the effectiveness of proposed method compared with a general PNG in terms of compression ratios and required memory in decoding processes. Also, the loading delay can be reduced by decoding only the displaying area of a large image in run-time.

Optimal Selection of Wavelet Coefficients for Electrocardiograph Compression

  • Del Mar Elena, Maria;Quero, Jose Manuel;Borrego, Inmaculada
    • ETRI Journal
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    • v.29 no.4
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    • pp.530-532
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    • 2007
  • This paper presents a simple method to implement a complete on-line portable wireless holter including an electrocardiogram (ECG) monitoring, processing, and communication protocol. The proposed algorithm significantly reduces the hardware resources of threshold estimation for ECG compression, using the standard deviation updated with each new input signal sample. The new method achieves superior performance in terms of hardware complexity, channel occupation and memory requirements, while keeping the ECG quality at a clinically acceptable level.

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A Hardware-Based String Matching Using State Transition Compression for Deep Packet Inspection

  • Kim, HyunJin;Lee, Seung-Woo
    • ETRI Journal
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    • v.35 no.1
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    • pp.154-157
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    • 2013
  • This letter proposes a memory-based parallel string matching engine using the compressed state transitions. In the finite-state machines of each string matcher, the pointers for representing the existence of state transitions are compressed. In addition, the bit fields for storing state transitions can be shared. Therefore, the total memory requirement can be minimized by reducing the memory size for storing state transitions.

Fast Image Compression and Pixel-wise Switching Technique for Hardware Efficient Implementation of Dynamic Capacitance Compensation (하드웨어 효율적인 동적 커패시턴스 보상 구현을 위한 고속 영상 압축 및 화소별 스위칭 기법)

  • Choi, Joon-Hwan;Song, Won-Suk;Choi, Hyuk
    • Journal of KIISE:Software and Applications
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    • v.36 no.8
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    • pp.616-622
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    • 2009
  • Thanks to Dynamic Capacitance Control (DCC) technique, response time of an LCD display has greatly improved. However, DCC requires hi-speed memory for the real-time writing/reading of an image of a previous frame, which results in increases in hardware overhead and cost. In this paper, we propose Modified Exponential Golomb (MEG) coding, a low-complex high-speed image compression method, which can remarkably reduce memory requirement for DCC. We also propose a pixel-wise DCC switching technique to prevent a compression error from affecting the quality of a final image on LCD. In our experiment, the degradation in visual quality was not noticeable when we cut the DCC memory size of 1080i HD data by 1/3.

Fine-scalable SPIHT Hardware Design for Frame Memory Compression in Video Codec

  • Kim, Sunwoong;Jang, Ji Hun;Lee, Hyuk-Jae;Rhee, Chae Eun
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.17 no.3
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    • pp.446-457
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    • 2017
  • In order to reduce the size of frame memory or bus bandwidth, frame memory compression (FMC) recompresses reconstructed or reference frames of video codecs. This paper proposes a novel FMC design based on discrete wavelet transform (DWT) - set partitioning in hierarchical trees (SPIHT), which supports fine-scalable throughput and is area-efficient. In the proposed design, multi-cores with small block sizes are used in parallel instead of a single core with a large block size. In addition, an appropriate pipelining schedule is proposed. Compared to the previous design, the proposed design achieves the processing speed which is closer to the target system speed, and therefore it is more efficient in hardware utilization. In addition, a scheme in which two passes of SPIHT are merged into one pass called merged refinement pass (MRP) is proposed. As the number of shifters decreases and the bit-width of remained shifters is reduced, the size of SPIHT hardware significantly decreases. The proposed FMC encoder and decoder designs achieve the throughputs of 4,448 and 4,000 Mpixels/s, respectively, and their gate counts are 76.5K and 107.8K. When the proposed design is applied to high efficiency video codec (HEVC), it achieves 1.96% lower average BDBR and 0.05 dB higher average BDPSNR than the previous FMC design.

Hangul Bitmap Data Compression Embedded in TrueType Font (트루타입 폰트에 내장된 한글 비트맵 데이타의 압축)

  • Han Joo-Hyun;Jeong Geun-Ho;Choi Jae-Young
    • Journal of KIISE:Software and Applications
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    • v.33 no.6
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    • pp.580-587
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    • 2006
  • As PDA, IMT-2000, and e-Book are developed and popular in these days, the number of users who use these products has been increasing. However, available memory size of these machines is still smaller than that of desktop PCs. In these products, TrueType fonts have been increased in demand because the number of users who want to use good quality fonts has increased, and TrueType fonts are of great use in Windows CE products. However, TrueType fonts take a large portion of available device memory, considering the small memory sizes of mobile devices. Therefore, it is required to reduce the size of TrueType fonts. In this paper, two-phase compression techniques are presented for the purpose of reducing the sire of hangul bitmap data embedded in TrueType fonts. In the first step, each character in bitmap is divided into initial consonant, medial vowel, and final consonant, respectively, then the character is recomposed into the composite bitmap. In the second phase, if any two consonants or vowels are determined to be the same, one of them is removed. The TrueType embedded bitmaps in Hangeul Wanseong (pre-composed) and Hangul Johab (pre-combined) are used in compression. By using our compression techniques, the compression rates of embedded bitmap data for TrueType fonts can be reduced around 35% in Wanseong font, and 7% in Johab font. Consequently, the compression rate of total TrueType Wanseong font is about 9.26%.

The Compression of Normal Vectors to Prevent Visulal Distortion in Shading 3D Mesh Models (3D 메쉬 모델의 쉐이딩 시 시각적 왜곡을 방지하는 법선 벡터 압축에 관한 연구)

  • Mun, Hyun-Sik;Jeong, Chae-Bong;Kim, Jay-Jung
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.1
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    • pp.1-7
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    • 2008
  • Data compression becomes increasingly an important issue for reducing data storage spaces as well as transmis-sion time in network environments. In 3D geometric models, the normal vectors of faces or meshes take a major portion of the data so that the compression of the vectors, which involves the trade off between the distortion of the images and compression ratios, plays a key role in reducing the size of the models. So, raising the compression ratio when the normal vector is compressed and minimizing the visual distortion of shape model's shading after compression are important. According to the recent papers, normal vector compression is useful to heighten com-pression ratio and to improve memory efficiency. But, the study about distortion of shading when the normal vector is compressed is rare relatively. In this paper, new normal vector compression method which is clustering normal vectors and assigning Representative Normal Vector (RNV) to each cluster and using the angular deviation from actual normal vector is proposed. And, using this new method, Visually Undistinguishable Lossy Compression (VULC) algorithm which distortion of shape model's shading by angular deviation of normal vector cannot be identified visually has been developed. And, being applied to the complicated shape models, this algorithm gave a good effectiveness.

Power Quality Monitoring Algorithm Using the Protective Relay (보호계전기를 이용한 전기 품질 감시 기법 연구)

  • Choi In. S.;Lee Kang. S.;Choi Myeon. S.;Lim Seong. I.;Lee Seung. J.
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.11
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    • pp.581-588
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    • 2004
  • Power qualify monitoring system is devoted to more concern than before, because the innovation of industrial technology needs more accurate instruments and more advanced power quality. This paper was studied on using data of the protective relay by Power Quality Monitor. This paper was proposed the wave storage condition and monitoring clauses of the protective relay as a power quality monitoring device. The protective relay will have problem to save data for PQM analysis because the protective relay memory is limited. Therefore this paper was proposed new a data compression of data got from the protective relay. This method is wave compression comparison algorithm using the DFT. The compression rate is higher than any other established method. This method can be real time storage. This algorithm is verified using the comparison among other compression rate and proved by Real Time Digital Simulator (RTDS).

EEG Data Compression Using the Feature of Wavelet Packet Coefficients (웨이블릿 패킷 분해를 이용한 EEG 신호압축)

  • Cho, Hyun-Sook;Lee, Hyoung;Hwang, Sun-Tae
    • Journal of Information Technology Applications and Management
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    • v.10 no.4
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    • pp.159-168
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    • 2003
  • This paper is concerned with the compression of EEG signals using wavelet-packet based techniques. EEG data compression is desirable for a number of reasons. Primarily it decreases for transmission time, archival storage space, and in portable systems, it decreases memory requirements or increases channels and bandwidth. Upon wavelet decomposition, inherent redundancies in the signal can be removed through thresholding to achieve data compression. We proposed the energy cumulative function for deciding of the threshold value and it works very innovative of EEG data.

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Location-Aware Hybrid SLC/MLC Management for Compressed Phase-Change Memory Systems (압축 기반 상변화 메모리 시스템에서 저장 위치를 고려한 하이브리드 SLC/MLC 관리 기법)

  • Park, Jaehyun;Lee, Hyung Gyu
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.2
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    • pp.107-116
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    • 2016
  • Density of Phase-Change Memory (PCM) devices has been doubled through the employment of multi-level cell (MLC) technology. However, this doubled-capacity comes in the expense of severe performance degradation, as compared to the conventional single-level cell (SLC) PCM. This negative effect on the performance of the MLC PCM detracts from the potential benefits of the MLC PCM. This paper introduces an efficient way of minimizing the performance degradation while maximizing the capacity benefits of the MLC PCM. To this end, we propose a location-aware hybrid management of SLC and MLC in compressed PCM main memory systems. Our trace-driven simulations using real application workloads demonstrate that the proposed technique enhances the performance and energy consumption by 45.1% and 46.5%, respectively, on the average, over the conventional technique that only uses a MLC PCM.