Description: 霍夫曼coding程序,用此程序可以对任意图像进行霍夫曼编码。-Huffman coding procedures, this procedure can be used for any image Huffman coding. Platform: |
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Author:许成哲 |
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Description: MATLAB实现霍夫曼编码对英文文本的解压缩程序-MATLAB Huffman coding for the English version of decompression procedures Platform: |
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Author:李明 |
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Description: This file contains a new and improved version of the Huffman coder, (June 29. 2001). The name is Huff06.m. There are also some additional files which are helpful when using Matlab for data compression: quantizer, different variants of run-length-encoding and end-of-block coding in Mat2Vec, and a program which do JPEG-like entropy coding. A complete compression example is shown in TestMat2Vec.m. This file is all you need for Huffman coding in MatLab.-This file contains a new and improved version of on of the Huffman coder, (June 29. 2001). The name is Huff06.m. There are also some additional files which are helpful wh en using Matlab for data compression : quantizer. different variants of run-length-encoding an d end-of-block coding in Mat2Vec. and a program which do JPEG-like entropy coding . A complete compression example is shown in Tes tMat2Vec.m. This file is all you need for Huffma n coding in MatLab. Platform: |
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Author:金金 |
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Description: matlab实现huffman编码,编码源为一系列简单符号,有运行结果。可自行改变源信息。-matlab achieve huffman coding, source coding for a series of simple symbols, there are results. Can change the source information. Platform: |
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Author:吉吉 |
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Description: 摘 要
文章以空间监控系统为背景,深入研究了JPEG图像压缩标准的实现方法,并基于FPGA对其进行了实现和优化。文中给出了详细的实现方法和优化过程,测试表明达到了很好的效果。
简单介绍了有损静态图像压缩当前有两种比较流行的标准JPEG和JPEG2000。说明了用JPEG方法压缩的原因。
介绍JPEG基本原理:JPEG对灰度图像的压缩处理过程主要包括:图像分割,离散余弦变换(DCT),量化(Quantization),“Z”形排序(Zigzag Scan),差分脉冲编码调制(Differential Pulse Code Modulation,DPCM)对直流系数(DC),行程长度编码(Run-Length Encoding,RLE)对交流系数(AC),霍夫曼(Huffman)编码等。
JPEG标准的特点是离散余弦变换。
比较详细介绍压缩系统的构成和实现。实现提及步骤, JPEG压缩模块设计和编码模块实现细节。
-Abstract
Article in the space monitoring system for the background, in-depth study of the JPEG image compression standard implementation methods and carried out based on FPGA implementation and optimization. In this paper, a detailed method of implementation and optimization of the process, testing showed that to achieve good results.
Easy introduction of harmful static image compression has two kinds of comparisons that the current popular standard JPEG and JPEG2000. Illustrated by the reasons for JPEG compression method.
JPEG introduce the basic principles: JPEG compression of gray-scale image processing include: image segmentation, discrete cosine transform (DCT), quantization (Quantization), "Z"-shaped sort (Zigzag Scan), differential pulse code modulation (Differential Pulse Code Modulation, DPCM) on the DC coefficient (DC), Run Length Encoding (Run-Length Encoding, RLE) of the exchange coefficient (AC), Hoffman (Huffman) coding.
JPEG standard is characterized by discrete Platform: |
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Author:压子 |
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Description: ) Compression using huffman code
-with a number of bits k per code word
-provide huffman table
Huffman coding is optimal for a symbol-by-symbol coding with a known input probability distribution.This technique uses a variable-length code table for encoding a source symbol. The table is derived in a particular way based on the estimated probability of occurrence for each possible value of the source symbol .Huffman coding uses a specific method for representing each symbol, resulting in a prefix code that expresses the most common characters using shorter strings of bits than those used for less common source symbols.The Huffman coding is a procedure to generate a binary code tree.
-) Compression using huffman code
-with a number of bits k per code word
-provide huffman table
Huffman coding is optimal for a symbol-by-symbol coding with a known input probability distribution.This technique uses a variable-length code table for encoding a source symbol. The table is derived in a particular way based on the estimated probability of occurrence for each possible value of the source symbol .Huffman coding uses a specific method for representing each symbol, resulting in a prefix code that expresses the most common characters using shorter strings of bits than those used for less common source symbols.The Huffman coding is a procedure to generate a binary code tree.
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Author:ria |
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Description: 利用霍夫曼编码算法对数字图像进行压缩及解压缩处理,解压出来的图像与源图像几乎完全一致,峰值信噪比为无穷大-The use of Huffman coding algorithm for digital image compression and decompression processing, extracting images from the source image is almost exactly the same infinite PSNR Platform: |
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Author:tianjieyu |
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Description: This a JPEG encoding & decoding program of still image. It does not use level shifting. Discrete Cosine transform (DCT) is performed both by classical & Chen s Flowgraph methods. Predefined JPEG quantization array & zigzag order are used here. RUN - LEVEL coding is used instead of Huffman coding. Compression ratio is compared for each DCT method. Effect of coarse and fine quantization is also examined. The execution time of 2 DCT methods is also checked. In addition, most energatic DCT coefficients are also applied to examine the effect in MatLab 7.4.0 R2007a. Input is 9 gray scale pictures & output is 9*9=81 pictures to compare. Blocking effect is obvious.
-This is a JPEG encoding & decoding program of still image. It does not use level shifting. Discrete Cosine transform (DCT) is performed both by classical & Chen s Flowgraph methods. Predefined JPEG quantization array & zigzag order are used here. RUN - LEVEL coding is used instead of Huffman coding. Compression ratio is compared for each DCT method. Effect of coarse and fine quantization is also examined. The execution time of 2 DCT methods is also checked. In addition, most energatic DCT coefficients are also applied to examine the effect in MatLab 7.4.0 R2007a. Input is 9 gray scale pictures & output is 9*9=81 pictures to compare. Blocking effect is obvious.
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Author:Ho Joon Lee |
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Description: Codes".
Huffman coding uses a specific method for choosing the representation for each symbol, resulting in a prefix code (sometimes called "prefix-free codes") (that is, the bit string representing some particular symbol is never a prefix of the bit string representing any other symbol) that expresses the most common characters using shorter strings of bits than are used for less common source symbols. Huffman was able to design the most efficient compression method of this type: no other mapping of individual source symbols to unique strings of bits will produce a smaller average output size when the actual symbol frequencies agree with those used to create the code. A method was later found to do this in linear time if input probabilities (also known as weights) are sorted.-Codes".
Huffman coding uses a specific method for choosing the representation for each symbol, resulting in a prefix code (sometimes called "prefix-free codes") (that is, the bit string representing some particular symbol is never a prefix of the bit string representing any other symbol) that expresses the most common characters using shorter strings of bits than are used for less common source symbols. Huffman was able to design the most efficient compression method of this type: no other mapping of individual source symbols to unique strings of bits will produce a smaller average output size when the actual symbol frequencies agree with those used to create the code. A method was later found to do this in linear time if input probabilities (also known as weights) are sorted.
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Author:muhammad |
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Description: HUFFMAN编码。对一片文章进行HUFFMAN编码,并计算它的信源熵,与编码后的平均码长进行比较。-HUFFMAN coding. Of an article to HUFFMAN coding, and calculate the entropy of its source, and the encoded average code length for comparison. Platform: |
Size: 10240 |
Author:gudeyi |
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Description: Implementation of JPEG compression algorithm with JFIF header being appended.This project involves writting code for following steps : Chroma subsampling,partitioning ,level shifting,DCT,quantization,zigzag scanning(involves DC differential coding & AC huffman coding) & adding jfif header following the rules specified in itu-t.81. Platform: |
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Author:dwn |
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Description: huffman编码用于图像的压缩和解压,很好用的,可以用于各类图像的处理-huffman coding for image compression and decompression, useful, and can be used for all kinds of image processing Platform: |
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Author:唐宁 |
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