Description: 数字图像处理实验
根据原图像的直方图,发现背景和目标的分割值大约在130左右,并将灰度图像转为二值图像,分割效果比较理想。
图像处理实验(六)图像压缩与编码
实验目的: 学习JPEG压缩编码
实验内容:
一.实现基本JPEG的压缩和编码分三个步骤:
1. 首先通过DCT变换去除数据冗余;
2. 使用量化表对DCT系数进行量化;
3. 对量化后的系数进行Huffman编码。-digital image processing experiments based on the original image histogram, found background and objectives of the divided about the value of around 130 and two gray-scale image to image, Segmentation more satisfactory results. Image processing experiments (6) Image Compression and Coding of the experiment : Learning JPEG compression coding experiment : one. Basically JPEG compression and coding in three steps : 1. First through DCT remove data redundancy; 2. Using quantitative table right DCT coefficient quantization; 3. Right quantized coefficients of Huffman coding. Platform: |
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Author:qq |
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Description: 实现基本JPEG的压缩和编码分三个步骤:
1. 首先通过DCT变换去除数据冗余;
2. 使用量化表对DCT系数进行量化;
3. 对量化后的系数进行Huffman编码。-Realize the basic JPEG compression and encoding is divided into three steps: 1. First of all, through the DCT transform to remove data redundancy 2. The use of quantization table of quantization DCT coefficients 3. Quantization coefficients after Huffman coding. Platform: |
Size: 2048 |
Author:后果 |
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Description: 实现JPEG的压缩和编码
(1)首先通过DCT变换去除数据冗余;
(2)使用量化表对DCT系数进行量化;
(3)对量化后的系数进行Huffman编码。
-The realization of JPEG compression and coding (1) First of all, through the DCT transform to remove data redundancy (2) the use of quantization table of quantization DCT coefficients (3) of the coefficients after quantization Huffman coding. Platform: |
Size: 2048 |
Author:李雅 |
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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: 编程实现基于8×8子块的DCT图像变换,基于JPEG量化矩阵的量化与反量化,基于8×8子块DCT的图像重建;以一幅512×512、8比特/象素的图像为实验对象,计算重建后的PSNR。-Programming based on 8 × 8 sub-block of the DCT image transform, quantization matrix based on the JPEG quantization and anti-quantitative, based on the 8 × 8 sub-block DCT of the image reconstruction to a 512 × 512,8 bits/as Su-image for the experiment, re-calculation of PSNR. Platform: |
Size: 111616 |
Author:zfyplay |
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Description: 对JPEG的压缩标准进行了仿真,主要过程DCT压缩,根据JPEG的量化矩阵对DCT结果进行量化,对量化结果进行Huffman编码。同时也实现了解压缩过程,即执行上述过程的逆过程。-JPEG compression standard of the simulation, the main process of DCT compression, according to the JPEG quantization matrix to quantify the results of the DCT, to quantify the results of Huffman coding. At the same time compression process to achieve understanding, that is, the inverse process of the implementation of the process. Platform: |
Size: 5120 |
Author:Justin |
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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.
Platform: |
Size: 1024 |
Author:Ho Joon Lee |
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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.
Platform: |
Size: 3072 |
Author:Ho Joon Lee |
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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.
Platform: |
Size: 128000 |
Author:Ho Joon Lee |
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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.
Platform: |
Size: 189440 |
Author:Ho Joon Lee |
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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.
Platform: |
Size: 95232 |
Author:Ho Joon Lee |
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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: |
Size: 966656 |
Author:dwn |
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Description: jpeg compression , use DCT, Zigzag, Quantization,IDCT, InvZigzag, huffman to do the compression with matlab Platform: |
Size: 5120 |
Author:phoenix |
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Description: JPEG图像压缩标准MATLAB仿真程序。包括DCT变换及其逆变换、量化及反量化等过程。-JPEG image compression standard MATLAB simulation program. Including the DCT transform and its inverse transform, quantization and inverse quantization and other processes. Platform: |
Size: 55296 |
Author:秋田 |
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Description: 给予matlab的JPEG压缩程序,包含原始压缩图片,程序对灰度bmp图片进行JEPG编码,压缩成以0101形式的编码。JPEG编码先把图象色彩RBG变成亮度Y和色度Cr、Cb,它利用人的视觉对色度不敏感的特点,减少一部分色度数据,以达到压缩。 JPEG采取多种编码方式,包含有行程编码(Run Length Coding)和哈夫曼(Huffman)编码,有很高的压缩比。在编码前,先对数据进行分块,离散余弦变换(DCT)及量化,保留能量大的低频信号,丢弃高频信号以达到压缩。-Given to the JPEG compression matlab program, contains the original compressed image, the program of the grayscale bmp picture JEPG encoded, compressed into a 0101 form of encoding. RBG color coded JPEG image into a first luminance Y and chrominance Cr, Cb, which uses the human visual characteristics is not sensitive to the color, reduce the number of color data to achieve compression. Take a variety of JPEG encoding, includes length coding (Run Length Coding) and Huffman (Huffman) coding, a high compression ratio. In the code before the data block, discrete cosine transform (DCT) and quantization, to retain a large low-frequency signal energy, discarding high-frequency signals in order to achieve compression. Platform: |
Size: 175104 |
Author: |
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Description: 使用matlab实现的jpeg基本系统,输入为灰度图像,输出为使用‘0’‘1’字符表示的字符串。
包括dct编码与解码、量化与反量化,Huffman编码与解码(The JPEG basic system implemented with MATLAB is entered into a gray image, and the output is a string represented with a '0' '1' character.
Including DCT coding and decoding, quantization and counter quantization, Huffman coding and decoding) Platform: |
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Author:笨笨木木
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