Description: 继 Discrete Cosine Transform: Algorithms, Advantages, Applications (K. R. Rao and P. Yip) 之后的一本关于离散余弦变换(DCT)的快速实现算法的最新专著. 本书第五章“Integer Discrete Cosine/Sine Transforms”关于DCT整数近似实现写的非常详细和精彩, 很方便大家编程实现. 值得一提的是本书的第一作者Vladimir Britanak 一直在从事DCT, 尤其是改进的离散余弦变换(MDCT)的快速算法的研究.-This book, which is written very carefully, is a new monograph of Discrete Cosine Transform (DCT).The fifth chapter about the Integer Discrete Cosine/Sine Transforms is especially wonderful. Platform: |
Size: 2693120 |
Author:伍家松 |
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Description: 该目录包含了基于可移植的C语言的数字水印算法的代码。这些代码具有示范
性的意义，且有一定的鲁棒性。
需要安装NetPGM的程序包（用来存取pgm格式图像），然后才能在linux下面编译。
NetPGM是图像文件的输入/输出软件包。可以在网上搜索得到。我们已经对
256灰度级，512×512大小的图像进行了测试。程序编译后的调用格式如下（以encode为例）：
wm_cox_e -s cox.sig -o wm_image.pgm image.pgm
其中，-s表示要添加的水印信号，cox.sig是信号文件。
-o表示输出图像文件名为wm_image.pgm，
image.pgm为输入文件名。
几个辅助程序：
cmp_pgm 计算差分图像，PSNR等
cmp_dct 计算全帧DCT域的差分图像
cmp_dct8x8 计算8×8大小的DCT域差分图像
比如说，为了产生两个PGM图像的差分图像并计算它们的PSNR，命令如下：
cmp_pgm -p -i original.pgm -o diff.pgm watermarked.pgm
产生水印信号：
gen_cox_sig -o cox.sig
程序将产生适合512×512大小，8-bit灰度的pgm图像的水印信号。
水印提取：
wm_cox_d -s cox.sig -i lena.pgm -o cox.wm cox_lena.pgm
请注意，cox的算法需要原始图像做参考来提取水印，压缩后的水印将存储在cox.wm中。-This directory contains the C-based portable digital watermarking algorithm code. The code has a demonstration
Of meaning, and there is a certain degree of robustness.
NetPGM need to install the package (to access the pgm format images), and then to compile in linux below.
NetPGM is the image file input/output package. Can search by. We have already
256 gray level, 512 × 512 size images were tested.
Procedure call format, compiled as follows (in encode an example):
wm_cox_e-s cox.sig-o wm_image.pgm image.pgm
Which,-s that you want to add the watermark signal, cox.sig is the signal file.
-O said output image file name wm_image.pgm,
image.pgm for the input file name.
Several auxiliary programs:
cmp_pgm calculate the difference image, PSNR, etc.
cmp_dct full frame DCT domain calculation of difference image
cmp_dct8x8 calculate the size of 8 × 8 DCT domain differential image
For example, in order to produce two PGM images and calculate their differ Platform: |
Size: 19456 |
Author:sylvia |
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Description: 本文在DCT噪声信号模型研究的基础上,提出了一种新的音频水印嵌入位置选择策略和一个应用该策略的自适应音频水印算法. 通过定义DCT系数的噪声敏感度,建立了水印嵌入位置和嵌入水印后的音频信号的听觉感知性之间的关系,根据音频水印的不可听性的要求选择最优的嵌入位置,然后调节水印强度来满足鲁棒性的要求,从而最大程度地保持音频水
印的不可听性和鲁棒性,为解决音频水印嵌入过程中不可听性和鲁棒性之间的矛盾提供了一种策略.-Though m any w orks in the literature agree that w aterm ark should be em bedded in the middle2fre2
quency coefficients or percep tually significant components, how to determ ine the position em bedded has no universal
definition. A new em bedding strategy and an algorithm app lying the strategy are p roposed for audio w aterm arking in
DCT dom ain based on research of DCT noise m odal. B y defining a noise sensitivity vector, a m ath relationship betw een
the w aterm ark em beddable position and the audible quality of the audio file w ith w aterm ark is set up. Platform: |
Size: 873472 |
Author:郑杨 |
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Description: . Write MATLAB code that will do the following.
(a) Apply DCT on an image and obtain the o/p
(b) On the DCT image apply quantization using standard quantiser. (8×8)
(c) Apply IDCT to retain back the image.
Apply Hoffman compression
-. Write MATLAB code that will do the following.
(a) Apply DCT on an image and obtain the o/p
(b) On the DCT image apply quantization using standard quantiser. (8×8)
(c) Apply IDCT to retain back the image.
Apply Hoffman compression
Platform: |
Size: 51200 |
Author:Rokibul Ahmed |
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Description: ElGamal algorithm not only used for data encryption can be used for digital signatures, their safety depends on the calculation of a finite field discrete logarithm this problem. Key to the method. First of all, choose a prime number p, the two random numbers, g and x, g, x <p, computing y = g ^ x (mod p), for its public key y, g and p. Private key is x. g and p by a group of users to share. ElGamal for digital signatures. Information was signed M, first choose a Platform: |
Size: 512000 |
Author:HamzaAnwer |
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Description: This the first comprehensive treatment of the oretical aspects of the discrete cosine transform (DCT), which is being recommended by various standards organizations, such as the CCITT, ISO etc., as the primary compression tool in digital image coding. The main purpose of the book is to provide a complete source for the user of this signal processing tool, where both the basics and the applications are detailed. An extensive bibliography covers both the theory and applications of the DCT. The novice will find the book useful in its self-contained treatment of the theory of the DCT, the detailed description of various algorithms supported by computer programs and the range of possible applications, including codecs used for teleconferencing, videophone, progressive image transmission, and broadcast TV. The more advanced user will appreciate the extensive references. Tables describing ASIC VLSI chips for implementing DCT, and motion estimation and details on image compression boards are also provided.-This is the first comprehensive treatment of the theoretical aspects of the discrete cosine transform (DCT), which is being recommended by various standards organizations, such as the CCITT, ISO etc., as the primary compression tool in digital image coding. The main purpose of the book is to provide a complete source for the user of this signal processing tool, where both the basics and the applications are detailed. An extensive bibliography covers both the theory and applications of the DCT. The novice will find the book useful in its self-contained treatment of the theory of the DCT, the detailed description of various algorithms supported by computer programs and the range of possible applications, including codecs used for teleconferencing, videophone, progressive image transmission, and broadcast TV. The more advanced user will appreciate the extensive references. Tables describing ASIC VLSI chips for implementing DCT, and motion estimation and details on image compression boards Platform: |
Size: 20508672 |
Author:张超 |
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