Description: 已知两个不同图像块亮度数据如下：
（1）分析DCT原理，采用DCT方法，编程并计算相应的DCT系数，分析系数分布特点。
（2）依据视觉特性分析量化表步长的分布特点，完成DCT系数量化。
（3）采用Z形扫描，实现输出数据的统计编码，形成Video stream。
（4）采用IDCT重建图像亮度数据，计算SAD大小，分析产生误差的原因及采用DCT进行数据压缩的原理。（ ）
（5）分别利用左上角1、3、6个系数重建图像，计算相应的SAD，并由此分析直流和低频系数的重要性。
-Known brightness of two different image data block is as follows: (1) Principles of analysis of DCT, the DCT method, program and calculate the corresponding DCT coefficient, analysis of distribution coefficients. (2) quantitative analysis based on visual characteristics of the distribution of long-form features step-by-step to complete the DCT coefficient quantization. (3) the use of Z-scan output data to achieve statistical encoding, the formation of Video stream. (4) the use of the reconstructed image brightness IDCT data to calculate the SAD size, analysis of the causes of errors and the use of DCT for the principle of data compression. () (5), respectively, a factor of 1,3,6 using the upper left corner of the reconstruction of images, calculating the corresponding SAD, and the resulting analysis of DC and the importance of low-frequency coefficients. Platform: |
Size: 1024 |
Author:张元 |
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Description: 运动估计是视频编码的关键技术，其最基本的原理是利用相邻帧间的时间
相关性，通过预测来减少时间冗余度。在实际编码中，为了节省码率，并不传
输每一帧的全部数据，而是利用运动估计求出每一帧与其预测参考帧之间的差
值。运动估计越准确，差值的分布越趋近与零，差值块的能量越小，经过变换、
量化和熵编码后所产生的码流的比特位率也越少。因此，运动估计搜索的准确
程度直接影响到了编码的压缩性能。
-Motion estimation is the key to video encoding technology, its basic principle is the use of the adjacent time frame relevant, through the forecast period to reduce redundancy. In the actual code, in order to save bit rate and does not transfer all the data of each frame, but the use of motion estimation for each frame obtained with the prediction of the difference between the reference frame. Motion estimation more accurate, more closer to the margin and the distribution of zero, the smaller the energy difference between blocks, after transform, quantization and entropy coding of the code produced by the bit stream bit rate is less. Therefore, the motion estimation search accuracy of the direct impact on the performance of the compression coding. Platform: |
Size: 17408 |
Author:罗鹏 |
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Description: mathworks网站上下的mpeg视频编码程序能正常运行，我对此进行了改进，可以正常运行，已经运行试验过多次。-mathworks site from top to bottom mpeg video encoding programs to resume normal operation, and I had improved, can be normal operation, has been running tests on many occasions. Platform: |
Size: 3672064 |
Author:帝王 |
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Description: ) 使用分块的主成分分析方法(PCA)对人脸图像进行压缩编码。针对PCA方法计算量大的缺点,首先把问题转化成奇异值分解(SVD)问题,然后设计了特征空间的更新算法,通过递推,简化每一步计算的计算量,达到了实时编码的要求。 4) 在Windows平台下基于Video for Windows(VFW)接口开发了人脸视频图像编码和解码的实验系统,该系统实现了图像采集、图像显示、编码、解码等功能。-) The use of sub-blocks of principal component analysis (PCA) on the human face image coding. PCA method for large defects, first of all the issues into a singular value decomposition (SVD) problem, and then design a feature space of the update algorithm, recursive, simplifying the calculation of the amount calculated at each step to achieve real-time encoding requirements. 4) In the Windows platform based on Video for Windows (VFW) interfaces, the human face image coding and decoding video experimental system, the system achieved image acquisition, image display, encoding, decoding functions. Platform: |
Size: 1024 |
Author:周参 |
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Description: 功能列表= mmwrite（文件名，选择... ...）
mmwrite是能写的AVI，WMV，的WMA，ASF文件。对于AVI文件，您可以选择从现有的编解码器压缩的音频和视频流。
对于WMV，WMA和ASF的编码默认为16位的Windows Media 9率为44100Hz立体声为98％质量的音频和Windows媒体视频9 98
质量。质量可以指定音频和视频。
环绕声，似乎只与AVI和多通道编码不支持。编写任何其他文件类型不支持。本使用Windows的DirectX基础设施，以便其他操作系统是出于运气。
输入：
文件名：这一定是第一个参数，并指定文件名写。
影片结构：视频结构相匹配的mmread输出。在最低限度，必须有4个领域的“框架”，“时代”，“高度”和“宽度”。该“框架”字段必须是一个结构与一个字段数组“的CDATA”的原始框架，它包含由彩色编码的数据宽度高度（3）UINT8s。钍-function list = mmwrite(filename,...options...)
mmwrite is able to write AVI,WMV,WMA,ASF files. For AVI files you can choose from the available codecs to compress the audio and video streams.
For WMV,WMA and ASF the encoding defaults to Windows Media 9 44100Hz 16bit stereo 98 quality for the audio and Windows Media 9 Video with 98
quality. The quality can be specified for both audio and video.
Surround sound only seems to work with AVI and multi-pass encoding is not supported. Writing any other file type is not supported. This uses Windows DirectX infrastructure, so other OSs are out of luck.
INPUT:
filename: This must be the first parameter and specifies the filename to write.
video structure: The video structure matches the output of mmread. At a minimum it must have 4 fields "frames", "times", "height" and "width". The "frames" field must be a struct array with a field "cdata" that contains the raw frame data encoded as height by width by color(3) as UINT8s. Th Platform: |
Size: 113664 |
Author:zaaa |
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Description: 实现对视频图像的游程编码和解码。过程包括：二维DCT变换、量化及游程编码。
一般来讲对于视频的I帧进行恢复，其信噪比可达到38DB以上。-Implementation of the video image encoding and decoding run-length. Process includes: two-dimensional DCT transform, quantization and run-length encoding. In general, I frame for the video resume, the signal to noise ratio can reach more than 38DB. Platform: |
Size: 7168 |
Author:zrs |
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Description: Video Compression using Content-Based Motion Compensation
---------------------------------------------------------
This demo Requires MATLAB (and the Image Processing Toolbox)
Tested on MATLAB 7.0 (R14).
Run one of the following three MATLAB scripts:
* DemoEncodeCrowd (encodes some frames from the "crowd" sequence)
* DemoDecodeCrowd (decodes the previously encoded frames)
* DemoDecode (generic decoder)
Note that the encoding script can be modified so that the user can specify the values of a number of input variables.
This code is VERY SLOW. A lot could be done to speed it up!
In MS-Windows, use the YUV file player to view YUV files.
-----------------------------------------
Based on the PhD Research of Marc Servais
www.ee.surrey.ac.uk/CVSSP/VMRG/hdtv/
-Video Compression using Content-Based Motion Compensation
---------------------------------------------------------
This demo Requires MATLAB (and the Image Processing Toolbox)
Tested on MATLAB 7.0 (R14).
Run one of the following three MATLAB scripts:
* DemoEncodeCrowd (encodes some frames from the "crowd" sequence)
* DemoDecodeCrowd (decodes the previously encoded frames)
* DemoDecode (generic decoder)
Note that the encoding script can be modified so that the user can specify the values of a number of input variables.
This code is VERY SLOW. A lot could be done to speed it up!
In MS-Windows, use the YUV file player to view YUV files.
-----------------------------------------
Based on the PhD Research of Marc Servais
www.ee.surrey.ac.uk/CVSSP/VMRG/hdtv/
-----------------------------------------
Platform: |
Size: 19207168 |
Author:mohammad665 |
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Description: 通信的数字化是它能与计算机技术和数字信号处理技术相结合的基础，而实现通信数字化的前提是信源能提供的各种用于传递的消息，例如语音、图像、数据、文字等都必须以数字化形式表示。而信源编码是数字通信系统中的重要组成部分，他是保证信号有效传输的一种重要方式。霍夫曼编码依据字符出现的概率来构造异字头的平均长度最短的码字，有时称之为最佳编码，其优越的性能被广泛使用在数字通信系统中。霍夫曼编码已经成为数据压缩的灵魂算法。本文介绍了无失真编码算法的构造，霍夫曼编码的规则和特点，同时分析了对信源进行优化的方法，最后通过MATLAB仿真来讨论比较二元霍夫曼编码、三元霍夫曼编码以及信源扩展编码的效率，来实现霍夫曼码的优化构造。-The digital communication is it can and computer technology and digital signal processing technology in combination of the base, and realize the digital communication is the premise of source can provide all kinds of used to deliver news, such as voice, video and data and text must take the digital form said. And the source coding digital communication system is the important component, he is to ensure the effective transmission signal is an important way. Huffman coding based on the probability of characters appear to construct different "the average length of the shortest code words, sometimes called the best coding, superior performance is widely used in digital communication system. Huffman coding has become the soul of data compression algorithm. This paper introduces the structure of the encoding algorithm without distortion, Huffman coding rules and characteristics, and analysis of the source of the optimization method, and finally by MATLAB simulation to discuss compares two yu Platform: |
Size: 59392 |
Author:郑华 |
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Description: Context-adaptive binary arithmetic coding (CABAC) is a form of entropy encoding used in the H.264/MPEG-4 AVC and High Efficiency Video Coding (HEVC) standards. It is a lossless compression technique, although the video coding standards in which it is used are typically for lossy compression applications. CABAC is notable for providing much better compression than most other entropy encoding algorithms used in video encoding, and it is one of the key elements that provides the H.264/AVC encoding scheme with better compression capability than its predecessors. Platform: |
Size: 16384 |
Author:rezajava
|
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Search - video encoding matlab