摘 要:圖像DC(離散余弦變換)是圖像壓縮的一項(xiàng)重要技術(shù),如何準(zhǔn)確、快速地進(jìn)行圖像壓縮一直是國內(nèi)外研究的熱點(diǎn)。首先闡述DC算法原理以及適合硬件設(shè)計(jì)的快速算法,介紹DP Builder信號(hào)處理平臺(tái),重點(diǎn)研究基于DP Builder 平臺(tái)的2D-DC硬件實(shí)現(xiàn)。在二維DC時(shí),采用一種存取數(shù)據(jù)時(shí)直接對(duì)數(shù)據(jù)轉(zhuǎn)置的方法,以提高設(shè)計(jì)速度。然后在Modelsim 62平臺(tái)下進(jìn)行功能仿真。最后將DP Builder 模塊轉(zhuǎn)換成VDL語言,并在QuartusRⅡ下進(jìn)行編譯和時(shí)序仿真,達(dá)到了理想的效果。
關(guān)鍵詞:DP Builder;DC變換;圖像壓縮;FPGA
Implementation on 2D-DC Based on DP Builder
WANG Xiaowei
(Chengdu University of echnology,Chengdu,61009,China)
Abstract:he image Discrete Cosine ransform(DC) is an important technique in the field of image compressionow to compress the image accurately and fast has been a research focus both at home and abroad all the timehis paper introduces the theory of DC and fast algorithm for DC,accomplishes its hardware design based on DP BuilderIn 2D-DC,it uses a fast way for data revolution when reading and writing datahen perform function simulation on Modelsim62At last,it translates the model into VDL and compiles it in QuartusRⅡ,a good result is obtained
Keywords:DP Builder;DC transformation;image compression;FPGA
DC變換由于其良好的去相關(guān)性,被廣泛運(yùn)用在數(shù)字圖像壓縮與編碼中。與DF相比,DC有許多優(yōu)點(diǎn),其中最突出的是:DF是復(fù)數(shù)域的運(yùn)算,而DC是實(shí)數(shù)運(yùn)算。同DF一樣,DC也有快速變換方法。在以JPEG,MPEG,26x為代表的圖像/視頻壓縮領(lǐng)域,對(duì)圖像進(jìn)行8×8的二維DC變換,只需少量的數(shù)據(jù)點(diǎn)表示圖像,并且它所產(chǎn)生的系數(shù)很容易被量化,在軟件和硬件上都很容易實(shí)現(xiàn)。
1 DP Builder介紹
DP Builder開發(fā)工具是Altera公司提供的數(shù)字信號(hào)處理平臺(tái),可以在MathWorks imulink環(huán)境下仿真導(dǎo)入的DL設(shè)計(jì),結(jié)合已有的imulink和DP Builder模型以及自己基于DL的設(shè)計(jì),進(jìn)行FPGA設(shè)計(jì)。設(shè)計(jì)人員能夠同時(shí)進(jìn)行多個(gè)DL模型或者QuartusRⅡ軟件設(shè)計(jì)工程,為每一個(gè)模塊生成一個(gè)獨(dú)立的仿真模型。并且能夠在同一設(shè)計(jì)環(huán)境中,以標(biāo)準(zhǔn)imulink/DP Builder模型來仿真DL模塊。此外,該工具可充分利用和重復(fù)使用現(xiàn)有設(shè)計(jì),這樣可以大大提高產(chǎn)品開發(fā)速度。在仿真軟件方面,除了可以利用imulink的仿真環(huán)境,DP Builder還提供了與Modelsim的接口,充分利用Modelsim仿真的優(yōu)勢(shì)。