Search - DCT compression in matlab

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[Special Effects] bianmashiyan DL : 0: 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.
Date : 2025-12-21 Size : 4kb User : qq
[Special Effects] dct_condense DL : 1: 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.
Date : 2025-12-21 Size : 34kb User : 张弛
[Special Effects] signal-analysis DL : 0: dctcom.m文件利用DCT变换完成对输入图像进行压缩；imagecbe.m完成对输入的两幅RGB图像用小波分析的方法进行图像融合 imagecom.m完成对输入的RGB图像用小波分析的方法进行自动降噪，得到高频系数阈值，降噪效果百分比和结果 wavelet1D.m完成对输入的一维信号进行多尺度离散小波分解 wavelet2D完成对输入的二维信号进行多尺度离散小波分解；zigzag.m完成对输入的8*8矩阵按照zigzag排列抽取数据.-document the use of DCT transform dctcom.m completion of the input image compression imagecbe.m completion of the two RGB input image with wavelet analysis method of image fusion imagecom.m completion of the input RGB image using wavelet analysis method automatically drop noise, the threshold of high-frequency coefficient, noise reduction effect and the results of the percentage of wavelet1D.m completion of the input signals of one-dimensional discrete wavelet multi-scale decomposition wavelet2D completion of the input signals of two-dimensional discrete wavelet multi-scale decomposition zigzag.m completed the input of 8* 8 matrix of data collected in accordance with the zigzag order.
Date : 2025-12-21 Size : 3kb User : zhouhao
[Special Effects] MPGextract DL : 0: 一个mpg压缩的水印提取程序,考虑到了几种压缩格式,并基于此提出DCT频率域上的水印提取.对学习视频水印的人有help-Mpg compressed a watermark extraction procedure, taking into account several types of compression formats, and based on this proposed DCT frequency domain watermark extraction. For learning video watermarking help people
Date : 2025-12-21 Size : 1kb User : zzy
[Special Effects] dct DL : 0: 利用DCT进行图像压缩（首先将图像分割成8×8的图像，对每个子图像进行DCT，这样每个子图像有64个系数，舍去50％小的变换系数，进行2：1的压缩。）-The use of DCT for image compression
Date : 2025-12-21 Size : 213kb User : nn
[Special Effects] DctSoft DL : 0: 基于DCT变换的二维图像压缩程序，在MATLAB中直接运行即可-Two-dimensional DCT-based image compression process can be run directly in MATLAB
Date : 2025-12-21 Size : 3kb User : 宋飞
[Special Effects] code DL : 1: 基于FFT变换、DCT变换、HT变换、小波变换和矢量量化技术的图像压缩的Matlab实现。-Based on the FFT transform, DCT transform, HT transform, wavelet transform and vector quantization image compression technology, the Matlab implementation.
Date : 2025-12-21 Size : 4kb User : Anna
[Special Effects] DCT_JPEG DL : 0: 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.
Date : 2025-12-21 Size : 171kb User :
[Special Effects] shuzituxiangchuli DL : 0: 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.
Date : 2025-12-21 Size : 3.99mb User : 李海宁
[Special Effects] A-Watermarking-Algorithm(MATLAB)-- DL : 1: 盲水印提取时不需要参考原始载体图像,在信息隐藏、版权保护等方面具有更广泛的应用前景。提出的盲水印算法在分块离散余弦变换(DCT)和离散小波变换(DWT)的基础上,利用关系双方DCT系数和DWT系数在受到攻击时具有相同变化趋势的特点,采用关系嵌入和量化嵌入的自适应选择嵌入策略,较大幅度地提高了盲水印提取的鲁棒性。同时在量化嵌入中采用抖动调制,实现了水印透明性和鲁棒性调节的便捷性。大量仿真实验结果表明该算法对噪声干扰、低通滤波、JPEG压缩、对比度增强等攻击有很好的鲁棒性和透明性。关键词数字水印盲水印关系嵌入量化嵌入离散余弦变换离散小波变换按这篇文章的算法，自己编的matlab,没有攻击时水印提取率为1，加水印后图像PSNR有45+，。有攻击后提取率也有0.9+。-Blind watermark extraction can be fulfilled without referring to the original host image. Therefore it hasmuch prospective applications in the fields of information hiding and copyright protection. Based on blocking Discrete Cosine Transform (DCT) and blocking DiscreteWaveletTransform (DWT), the proposed blind watermarking algorithm uses an embedding strategy of adaptively selecting either relationship embedding or quantization embedding. The relationship em- bedding comes from the observation thatboth themagnitudes of coefficients concerned in the relationship usually have thesame change trend when the image is attacked. This strategy remarkably improves the robustness ofwatermark extraction.In addition, dithermodulation is used in quantization embedding, bywhich the tradeoff between transparency and robus-tness ofwatermarking can be easily adjusted. Simulation results show that the algorithm is fairly robust against the attacks such as noise, filtering, compression, and contrast
Date : 2025-12-21 Size : 741kb User : CXF