scholarly journals C-Pack: Cache Compression for Microprocessor Performance

2011 ◽  
pp. 102-107
Author(s):  
T. Narasimhulu
Keyword(s):  
Power Consumption ◽  
Data Compression ◽  
Lossless Compression ◽  
Register Transfer Level ◽  
Improve Performance ◽  
Memory Hierarchies ◽  
Compression Algorithms ◽  
Cache Line ◽  
On Line ◽  
Cache Compression

Computer systems and micro architecture researchers have proposed using hardware data compression units within the memory hierarchies of microprocessors in order to improve performance, energy efficiency, and functionality. However, most past work, and all work on cache compression, has made unsubstantiated assumptions about the performance, power consumption, and area overheads of the proposed compression algorithms and hardware. In this work, I present a lossless compression algorithm that has been designed for fast on-line data compression, and cache compression in particular. The algorithm has a number of novel features tailored for this application, including combining pairs of compressed lines into one cache line and allowing parallel compression of multiple words while using a single dictionary and without degradation in compression ratio. We reduced the proposed algorithm to a register transfer level hardware design, permitting performance, power consumption, and area estimation.

scholarly journals A VLSI Approach for Cache Compression in Microprocessor

2011 ◽  
pp. 187-191
Author(s):  
Sharada Guptha M N ◽  
H. S. Pradeep ◽  
M Z Kurian
Keyword(s):  
Power Consumption ◽  
Compression Ratio ◽  
Memory System ◽  
Memory Access ◽  
Access Time ◽  
Compression Algorithms ◽  
Past Work ◽  
Cache Line ◽  
On Chip ◽  
Cache Compression

Speed is one of the important issues that generally customers consider for selecting any electronic component in the market. Speed of a microprocessor based system mainly depends on the speed of the microprocessor which in turn depends on the memory access time. Accessing on chip memory takes more time than accessing off-chip memory. Because of these, designers of memory system may find cache compression as an advantageous method to increase speed of a microprocessor based system, as it increases cache capacity and off-chip bandwidth. The However, most past work, and all work on cache compression, has made unsubstantiated assumptions about the performance, power consumption, and area overheads of the proposed compression algorithms and hardware. It is not possible to determine whether compression at levels of the memory hierarchy closest to the processor is beneficial without understanding its costs. Proposed hardware compression algorithms fall into the dictionary-based category, which depend on building a dictionary and using its entries to encode repeated data values. Proposed algorithm has number of novel features like including combining pairs of compressed lines into one cache line and allowing parallel compression of multiple words while using a single dictionary and without degradation in compression ratio.

scholarly journals Constructing Binary Huffman Tree

2013 ◽  
Vol 21 (2) ◽  
pp. 133-143
Author(s):  
Hiroyuki Okazaki ◽  
Yuichi Futa ◽  
Yasunari Shidama
Keyword(s):  
Data Compression ◽  
Binary Code ◽  
Lossless Compression ◽  
Huffman Coding ◽  
Compression Algorithms ◽  
Huffman Encoding ◽  
Lossless Data Compression ◽  
Entropy Encoding

Summary Huffman coding is one of a most famous entropy encoding methods for lossless data compression [16]. JPEG and ZIP formats employ variants of Huffman encoding as lossless compression algorithms. Huffman coding is a bijective map from source letters into leaves of the Huffman tree constructed by the algorithm. In this article we formalize an algorithm constructing a binary code tree, Huffman tree.

scholarly journals Second compression for pixelated images under edge-based compression algorithms: JPEG-LS as an example

2021 ◽  
pp. 1-9
Author(s):  
Kamal Al-Khayyat ◽  
Imad Al-Shaikhli ◽  
Mohamad Al-Hagery
Keyword(s):  
Data Compression ◽  
Compression Ratio ◽  
Lossless Compression ◽  
General Purpose ◽  
Compression Algorithm ◽  
Random Data ◽  
Data Set ◽  
Compression Algorithms ◽  
Edge Based

This paper details the examination of a particular case of data compression, where the compression algorithm removes the redundancy from data, which occurs when edge-based compression algorithms compress (previously compressed) pixelated images. The newly created redundancy can be removed using another round of compression. This work utilized the JPEG-LS as an example of an edge-based compression algorithm for compressing pixelated images. The output of this process was subjected to another round of compression using a more robust but slower compressor (PAQ8f). The compression ratio of the second compression was, on average,  18%, which is high for random data. The results of the second compression were superior to the lossy JPEG. Under the used data set, lossy JPEG needs to sacrifice  10% on average to realize nearly total lossless compression ratios of the two-successive compressions. To generalize the results, fast general-purpose compression algorithms (7z, bz2, and Gzip) were used too.

scholarly journals A Computable Measure of Algorithmic Probability by Finite Approximations with an Application to Integer Sequences

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Fernando Soler-Toscano ◽  
Hector Zenil
Keyword(s):  
Lossless Compression ◽  
Integer Sequences ◽  
Compression Algorithms ◽  
Finite Approximations ◽  
Complementary Approach ◽  
On Line ◽  
Error Estimations ◽  
Program Description ◽  
Formal Properties ◽  
Computable Measure

Given the widespread use of lossless compression algorithms to approximate algorithmic (Kolmogorov-Chaitin) complexity and that, usually, generic lossless compression algorithms fall short at characterizing features other than statistical ones not different from entropy evaluations, here we explore an alternative and complementary approach. We study formal properties of a Levin-inspired measure m calculated from the output distribution of small Turing machines. We introduce and justify finite approximations mk that have been used in some applications as an alternative to lossless compression algorithms for approximating algorithmic (Kolmogorov-Chaitin) complexity. We provide proofs of the relevant properties of both m and mk and compare them to Levin’s Universal Distribution. We provide error estimations of mk with respect to m. Finally, we present an application to integer sequences from the On-Line Encyclopedia of Integer Sequences, which suggests that our AP-based measures may characterize nonstatistical patterns, and we report interesting correlations with textual, function, and program description lengths of the said sequences.

scholarly journals Efficient Lossless Compression of Multitemporal Hyperspectral Image Data

2018 ◽  
Vol 4 (12) ◽  
pp. 142 ◽  
Author(s):  
Hongda Shen ◽  
Zhuocheng Jiang ◽  
W. Pan
Keyword(s):  
Data Compression ◽  
Hyperspectral Image ◽  
Image Data ◽  
Lossless Compression ◽  
Large Data ◽  
Hyperspectral Data ◽  
Compression Performance ◽  
Temporal Correlations ◽  
Sensing Applications ◽  
Data Volume

Hyperspectral imaging (HSI) technology has been used for various remote sensing applications due to its excellent capability of monitoring regions-of-interest over a period of time. However, the large data volume of four-dimensional multitemporal hyperspectral imagery demands massive data compression techniques. While conventional 3D hyperspectral data compression methods exploit only spatial and spectral correlations, we propose a simple yet effective predictive lossless compression algorithm that can achieve significant gains on compression efficiency, by also taking into account temporal correlations inherent in the multitemporal data. We present an information theoretic analysis to estimate potential compression performance gain with varying configurations of context vectors. Extensive simulation results demonstrate the effectiveness of the proposed algorithm. We also provide in-depth discussions on how to construct the context vectors in the prediction model for both multitemporal HSI and conventional 3D HSI data.

Research on Compressed Sensing Matrix Based on Data Compressing of Insulator Leakage Current

2013 ◽  
Vol 475-476 ◽  
pp. 451-454
Author(s):  
Xue Ming Zhai ◽  
Xiao Bo You ◽  
Ruo Chen Li ◽  
Yu Jia Zhai ◽  
De Wen Wang
Keyword(s):  
Compressed Sensing ◽  
Data Compression ◽  
Leakage Current ◽  
Sparse Matrix ◽  
Circulant Matrix ◽  
Measurement Matrix ◽  
Sensing Matrix ◽  
Significant Step ◽  
On Line

Insulator fault may lead to the accident of power network,thus the on-line monitoring of insulator is very significant. Low rates wireless network is used for data transmission of leakage current. Making data compression and reconstruction of leakage current with the compressed sensing theory can achieve pretty good results. Determination of measurement matrix is the significant step for realizing the compressed sensing theory. This paper compares multiple measurement matrix of their effect via experiments, putting forward to make data compression and reconstruction of leakage current using Toeplitz matrix, circulant matrix and sparse matrix as measurement matrix, of which the reconstitution effect is almost the same as classical measurement matrix and depletes computational complexity and workload.

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