本論文主要介紹了JPEG的編碼和解碼過程。該程序的編碼部分能把一張BMP格式的圖象進(jìn)行JEPG編碼，壓縮成以二進(jìn)制形式保存的文件；通過相應(yīng)的解碼程序又可以把圖象解壓縮出來。在圖象傳送過程中，我們經(jīng)常采用JPEG格式對(duì)靜態(tài)圖象進(jìn)行編碼。JPEG基本系統(tǒng)是一種有損編碼，無法完全恢復(fù)出原圖象，信息有一定的丟失，稱為有損壓縮。盡管我們希望能夠無損壓縮，但是通常有損壓縮的壓縮比(即原圖象占的字節(jié)數(shù)與壓縮后圖象占的字節(jié)數(shù)之比，壓縮比越大，說明壓縮效率越高)比無損壓縮的高。JPEG編碼先把圖象色彩RBG變成亮度Y和色度Cr、Cb，它利用人的視覺對(duì)色度不敏感的特點(diǎn)，減少一部分色度數(shù)據(jù)，以達(dá)到壓縮。 JPEG采取多種編碼方式，包含有行程編碼(Run Length Coding)和哈夫曼(Huffman)編碼，有很高的壓縮比。在編碼前，先對(duì)數(shù)據(jù)進(jìn)行分塊，離散余弦變換（DCT）及量化，保留能量大的低頻信號(hào)，丟棄高頻信號(hào)以達(dá)到壓縮。解碼時(shí)，進(jìn)行熵解碼，反量化，反離散余弦變換（IDCT）。
上傳時(shí)間： 2013-12-21
上傳用戶：coeus
1）I：初始化（Initialization）。從終端讀入電文，寫到tobetrans文件中，統(tǒng)計(jì)電文的字符集合和對(duì)應(yīng)的權(quán)值集合，建立哈夫曼樹，并將哈夫曼樹存于文件hfmtree中。 （2）C：編碼（Coding ）。利用已建好的哈夫曼樹（如不在內(nèi)存，則從文件hfmtree中讀入），對(duì)文件tobetrans中的正文進(jìn)行編碼，然后將結(jié)果存入文件codefile中。 （3）D：譯碼（Decoding）。利用已建好的哈夫曼樹將文件codefile中的代碼進(jìn)行譯碼，結(jié)果存入文件textfile中。 （4）P：印代碼文件（Print）。將文件codefile以緊湊格式顯示在終端上，每行50個(gè)代碼。同時(shí)將此字符形式的編碼文件寫入文件codeprint中。 （5）T：印哈夫曼樹（Tree printing）。將已在內(nèi)存中的哈夫曼樹以直觀的方式（樹或凹入表形式）顯示在終端上，同時(shí)將此字符形式的哈夫曼樹寫入文件treeprint中。 用戶界面要求設(shè)計(jì)為“菜單”方式。 修改你的系統(tǒng)，實(shí)現(xiàn)對(duì)你的系統(tǒng)的源程序的編碼和譯碼（主要是將行尾符編/譯碼問題）。實(shí)現(xiàn)各個(gè)轉(zhuǎn)換操作的源/目標(biāo)文件，均由用戶在選擇此操作時(shí)指定。
標(biāo)簽： Initialization 初始化
上傳時(shí)間： 2014-01-04
上傳用戶：windwolf2000
D169 Demo - DMA0 Repeated Burst to-from RAM, Software Trigger Description A 32 byte block from 220h-240h is transfered to 240h-260h using DMA0 in a burst block using software DMAREQ trigger. After each transfer, source, destination and DMA size are reset to inital software setting because DMA transfer mode 5 is used. P1.0 is toggled durring DMA transfer only for demonstration purposes. ** RAM location 0x220 - 0x260 used - always make sure no compiler conflict ** ACLK= n/a, MCLK= SMCLK= default DCO ~ 800k
標(biāo)簽： Description Repeated Software to-from
上傳時(shí)間： 2014-01-09
上傳用戶：thinode
The main file in this list of programs is "vblast.m". Type "help vblast" on the command line for details.Study the coding by stepping through the program. These programs require around 5000 packets for reasonable plotting accuracy.This has been implemented for a 2x2 system. The reader can program other variations. The program has been tested on MATLAB version 6.0 and above with signal processing toolbox and communication toolbox options.
標(biāo)簽： vblast programs command main
上傳時(shí)間： 2016-08-24
上傳用戶：wcl168881111111
This chapter contains sample programs for determining capacity. The reader is advised to go through the coding. The file "capacity_water.m" is for measuring the waterfilling capacity. It should be made to work with a file similar to "capacity_plot_main.m". The latter file deals with all the other capacity plots given in the book in Chapter 2. All programs are verified with MATLAB versions 6.0 and above with signal processing and communications toolboxes.
標(biāo)簽： determining capacity contains programs
上傳時(shí)間： 2016-08-24
上傳用戶：yph853211
This a very simple baseband simulator for SC-FDMA system. This simulator is part of the upcoming book “Single Carrier FDMA: A New Air Interface for Long Term Evolution” (Wiley, Nov. 2008) which I co-authored with professor David J. Goodman at Polytechnic University. The purpose of this simulator is to give some concrete idea of how SC-FDMA system works. It does lack many realistic and sophisticated features such as channel coding, time-varying fading channel model, soft decision decoding, etc. Regardless, I am hoping that it will help you understand SC-FDMA which is a fairly new development in 3GPP LTE.
標(biāo)簽： simulator This baseband upcoming
上傳時(shí)間： 2016-08-26
上傳用戶：小草123
This directory includes matlab interface of the curvelet transform using usfft. Basic functions fdct_usfft.m -- forward curvelet transform afdct_usfft.m -- adjoint curvelet transform ifdct_usfft.m -- inverse curvelet transform fdct_usfft_param.m -- returns the location of each curvelet in phase-space Useful tools fdct_usfft_dispcoef.m -- returns a matrix contains all curvelet coefficients fdct_usfft_pos2idx.m -- for fixed scale and fixed direction, returns the curvelet which is closest to a certain point on the image Demos fdct_usfft_demo_basic.m -- display the shape of a curvelet fdct_usfft_demo_recon.m -- partial reconstruction using curvelet fdct_usfft_demo_disp.m -- display all the curvelet coefficients of an image fdct_usfft_demo_denoise.m -- image denoising using curvelet
標(biāo)簽： directory functions interface transform
上傳時(shí)間： 2016-08-31
上傳用戶：cooran
DevExpress.ExpressFlowChart.Suite.v1.37.for.Delphi.BCB.Full.Source-SSG delphi 和 BCB的源碼，次空間可以幫你輕松實(shí)現(xiàn)流程圖類的圖標(biāo)功能，強(qiáng)烈推薦！ The ExpressFlowChart is designed to help you present charts, schemes, hierarchies, and graphs of any complexity with minimal coding and programming effort. The ExpressFlowChart Suite offers all the necessary tools and elements to create dazzling interfaces limited only by your imagination and the needs of your end-users.
標(biāo)簽： ExpressFlowChart DevExpress Source-SSG BCB
上傳時(shí)間： 2016-09-29
上傳用戶：363186
This project should serve as an "easy start" with embOS. All pathes are relative to the project file. You should therefor be able to copy the entire directory (including all subdirectories) to any location on your harddrive.
標(biāo)簽： project relative pathes should
上傳時(shí)間： 2013-12-28
上傳用戶：王楚楚
With the advent of multimedia, digital signal processing (DSP) of sound has emerged from the shadow of bandwidth-limited speech processing. Today, the main appli- cations of audio DSP are high quality audio coding and the digital generation and manipulation of music signals. They share common research topics including percep- tual measurement techniques and analysis/synthesis methods. Smaller but nonetheless very important topics are hearing aids using signal processing technology and hardware architectures for digital signal processing of audio. In all these areas the last decade has seen a significant amount of application oriented research.
標(biāo)簽： multimedia processing the digital
上傳時(shí)間： 2014-01-23
上傳用戶：xwd2010
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