【正文】 DCT 快速算法分析及在圖像壓縮編碼中的應(yīng)用 Application of DCT Fast Algorithm Analyse in Image Compression Code 專 業(yè)： 電子信息科學(xué)與技術(shù) 學(xué) 號(hào)： 03111230 姓 名： 指導(dǎo)教師： 目錄 內(nèi)容摘要 ...................................................................................................................... I Abstract........................................................................................................................ II 第一章 離散余弦變換 ........................................................................................... 1 引 言 ........................................................................................................... 1 離散余弦變換定義 ....................................................................................... 1 DCT 的算法 .................................................................................................... 2 DCT 快速算法的研究 .................................................................................... 2 第 二章 圖像壓縮編碼的綜述 ................................................................................. 4 圖象壓縮的目的和方法 ............................................................................... 4 圖象壓縮的目的 ........................................................................................... 4 圖象壓縮的幾種方法 ................................................................................... 4 ................................................................................................... 6 第三章 JPEG 編碼算法 ........................................................................................... 7 JPEG 壓縮編碼基礎(chǔ) ..................................................................................... 7 JPEG 算法于 JPEG 小組簡介 ...................................................................... 7 JPEG 壓縮 ..................................................................................................... 8 JPEG 中的二維 DCT .................................................................................... 8 DCT 的實(shí)現(xiàn) ................................................................................................ 9 第四章 壓縮過程 ..................................................................................................... 12 DCT 的輸出 ................................................................................................. 12 量化 ............................................................................................................. 12 量化的算法描述 .......................................................................................... 12 量化矩陣的選擇 ......................................................................................... 13 編碼 ........................................................................................................... 14 Zig－ Zag序列 .......................................................................................... 14 熵編碼 ....................................................................................................... 16 結(jié)束語 ....................................................................................................................... 19 參 考 文 獻(xiàn) ............................................................................................................. 20 致謝 ........................................................................................................................... 21 襄樊學(xué)院畢業(yè)論文（設(shè)計(jì)） I 內(nèi)容 摘要 本文主要介紹兩個(gè)方面： DCT 快速算法和圖像壓縮編碼。首先介紹離散余弦變換的定義及其變換方法，并介 紹離散余弦變換的幾種快速算法 ，提出六種離散余弦變換的快速算法 . 其次講述圖像壓縮（ JPEG）的目的和編碼 算法的基本原理，分析圖象壓縮編碼的幾種應(yīng)用方法，著重說明 DCT算法在圖象壓縮中的廣泛應(yīng)用。以及離散余弦變換（ DCT）算法在圖像壓縮編碼中的實(shí)現(xiàn)過程。利用離散余弦變換 的某些特點(diǎn)去 減少搜索塊的數(shù)目和縮小搜索塊的范圍兩方面減少分形圖像的編碼時(shí)間。為了減少對(duì)圖像的質(zhì)量影響，對(duì)于編碼恢復(fù)的圖像采用了圖像平滑的處理方式減少塊效應(yīng)并 提出最恰當(dāng)一種快速算法應(yīng)用于圖像壓縮編碼中。 還介紹了在圖象壓縮過程中的離散余弦變換、量化和編碼三個(gè)重要步驟的實(shí)現(xiàn)原理。 關(guān)鍵詞 ： 離散余弦變換 ， 圖像壓縮編碼 ， 快速算法 ， 量化 襄樊學(xué)院畢業(yè)論文（設(shè)計(jì)） II Abstract In this article, the author mainly introduces two aspects: DCT fast algorithm and image pression code. First this paper explains the definition of discrete cosine transformation and the transformation method, and then introduces several kinds of fast and discrete cosine transformation and research, proposes six kinds of discrete cosine transformations fast algorithm .Second, the goal of image pression (JPEG) and the code algorithm basic on principle has been presented, with the method of image pression applications being analyzed, the widespread using of DCT in image pression, as well as discrete cosine transformation (DCT) algorithm implement process in image pression code being emphasized. The picture code processing time can be reduced in two ways, by reducing the search block number and by reducing search block scope respectively. In order to avoid some influence on the picture quality , the most appropriate solution of picture smooth processing, has been proposed to reduce the influence. Also three important steps the realization principles of discrete cosine transformation and quantification and codes in the image process are introduced. Keywords: Discrete cosine transformation, Image pression