Description: 余弦变换压缩，用于图像压缩，压缩比高，且压缩后图像质量仍然很好。适用于灰度图象。-Cosine Transform compression for image compression, compression ratio, and compressed image quality is still good. Apply to the gray-scale image. Platform: |
Size: 34816 |
Author:张弛 |
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Description: 对任意大小的灰度图像进行zig-zag变换和反变化，或者是对DCT之后的图像进行zig-zag变换，确定其中频信息。-Any size of gray-scale images in zig-zag transform and anti-change, or is the DCT of the image after the zig-zag transform, to determine which frequency information. Platform: |
Size: 128000 |
Author:晁文婷 |
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Description: 由于二维DCT变换是对数字图像矩阵而言的，所以对于RGB位图不能进行DCT变换我在这里先将它转换成灰度图像再把水印嵌入到灰度图像中来进行基于DCT变换的图像水印研究。-As the two-dimensional DCT transform on the digital image matrix is concerned, therefore, for the RGB bitmap should not be DCT Transform I first convert it into gray image and then watermark is embedded into gray-scale images for image based on the DCT Transform watermarking research. Platform: |
Size: 1024 |
Author:chf068 |
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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: |
Size: 523264 |
Author:压子 |
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Description: 该gui函数基本上包括图像处理里面的最基本处理，相当于一个小型photoshop。比如读取文件，几何变换中的垂直镜像，平移，旋转，缩放；正交变换的DFT，FFT，DCT，DST，DHT，DWashT；灰度处理中的反色，直方图均衡，全局线性变换，分段线性变换，指数非线性变换，对数非线性变换；图像增强里面的加噪声，平滑，锐化，伪彩色增强；图像分割里面的灰度阈值法，Robert，Laplace，sobel，prewitt，canny算子边缘检测法；图像恢复里面的直接逆滤波，维纳滤波；图像编码里面的霍夫曼编码，行程编码-Basically, the gui functions including the most basic image processing inside the handle, which is equivalent to a small photoshop. For example, read the document, the geometric transformation of the vertical mirroring, shifting, rotating, zooming orthogonal transformation of the DFT, FFT, DCT, DST, DHT, DWashT anti-gray color processing, histogram equalization, global linear transformation , piecewise linear transformation, index of non-linear transform of the number of non-linear transformation image enhancement which increases the noise, smoothing, sharpening, pseudo-color enhancement the gray-scale image segmentation inside the threshold, Robert, Laplace, sobel, prewitt, canny edge detection operator method image restoration inside direct inverse filtering, Wiener filtering image coding inside the Huffman code, and so on Run-Length Coding Platform: |
Size: 398336 |
Author:guhuxiang |
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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: 对原始灰度图像进行图像压缩，对此图进行 8×8 DCT 变换后，分别只保留 DC系数，以及保留前 4、8、16 个变换系数(DC＋AC) ，然后再分别进行 IDCT 变换
-The original gray image compression, this map for 8 × 8 DCT transform, respectively, to retain only the DC coefficient, and to retain the former 4,8,16 months transform coefficients (DC+ AC), and then separately IDCT transform Platform: |
Size: 1024 |
Author:potato |
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Description: 作业一
要求
用C语言或者VC，VB，Matlab或其他语言完成如下实验：
1）打开一个BMP文件
2）将其局部区域的灰度值进行改变
3）另存为一个新的BMP文件
要求显示出原BMP图像和新BMP图像。
作业二
要求
1. 编程实现图像傅立叶高通、低通滤波。
2. 尝试傅立叶压缩。
作业三
要求
编程实现图像DCT高通、低通滤波。并与傅里叶变换比较。
作业四
要求
找一幅曝光不足的灰度（或彩色）图像，按照直方图均衡化方法进行处理。
作业五（一）
要求
打开一幅图像，添加椒盐、高斯噪声，然后使用邻域平均法、中值滤波法、K邻近平均法进行平滑。
作业五（二）
要求
打开一幅图像，利用Roberts梯度法、Sobel算子和拉普拉斯算子进行锐化，并比较结果。
-Operating a
Requirements
C or VC, VB, Matlab or any other language, complete the following experiment:
1) Open a BMP file
2) the gray value of its local area change
3) Save as a new BMP file
Requirement that the original BMP images and BMP images.
Task 2
Requirements
A programming image Fourier high-pass, low pass filtering.
Try Fourier compression.
Assignment 3
Requirements
Programming to achieve high-pass, low pass filtering, image DCT. And compared with the Fourier transform.
Fourth Assignment
Requirements
Looking for an exposure less than the gray (or color) image to be processed in accordance with the histogram equalization method.
Assignment 5 (a)
Requirements
Open an image, add salt and pepper, Gaussian noise, and then use the neighborhood average, median filter, K, close to the average method of smoothing.
Assignment 5 (b)
Requirements
Open an image, use the gradient method of Roberts, Sobel operator and Laplacian sharpening, and compare the results. Platform: |
Size: 4187136 |
Author:李海宁 |
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Description: 用matlab编程工具，编写具有操作界面的应用程序，通过菜单、对话框，选项框等界面控制，对算法进行演示。需要在应用系统中实现的算法及功能包括：
1、图像增强算法
（1）灰度线形变换：亮度及对比度可以调节（通过控制参数的改变，能够实时预览变化结果）；
（2）直方图均衡：可在界面上对比均衡前后的效果。
2、图像变换算法
（3）对一幅彩色图像进行DCT变换和反变换，对比结果和原图；
（4）仅保留左上角16X16的DCT系数，进行反变换，计算结果图的信噪比SNR。
3、图像分割算法
（5）采用最优阈值算法对灰度图像进行分割；
（6）用Canny算法对灰度图像进行边缘检测；
（7）用hough变换，检测边缘图像中的直线，并用不同颜色将检测出的直线叠加显示到原图像上。
-Preparation of a user interface with Matlab programming tools, applications, menus, dialog boxes, option boxes and other interface control, the algorithm demo. Algorithms and functions that need to be achieved in the application system including: 1, the image enhancement algorithm (1) gray linear transformation: the brightness and contrast can be adjusted (by controlling the change of the parameters, it is possible to real-time preview changes result) (2) Histogram equalization : contrast before and after equalization effect in the interface. 2, an image transformation algorithm (3) for a color image DCT transform and inverse transform, comparing the results and the original (4) to retain only the upper left corner of 16x16 DCT coefficient, the inverse transform, the signal-to-noise ratio SNR calculation results of FIG. . 3, image segmentation algorithm (5) The optimal threshold algorithm to gray-scale image segmentation (6) Canny algorithm for edge detection of gray-scale images ( Platform: |
Size: 822272 |
Author:张涛 |
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Search - DCT for gray image MATLAB