freepeople性欧美熟妇, 色戒完整版无删减158分钟hd, 无码精品国产vα在线观看DVD, 丰满少妇伦精品无码专区在线观看,艾栗栗与纹身男宾馆3p50分钟,国产AV片在线观看,黑人与美女高潮,18岁女RAPPERDISSSUBS,国产手机在机看影片

正文內(nèi)容

基于三維激光掃描數(shù)據(jù)的三維模型重建技術(shù)研究論文-免費(fèi)閱讀

2024-12-05 13:00 上一頁面

下一頁面
  

【正文】 三維空間的旋轉(zhuǎn)相比二維平面復(fù)雜得多,二維旋轉(zhuǎn)是在平面上進(jìn)行的,三維空間旋轉(zhuǎn)則不同,可以圍繞坐標(biāo)軸旋轉(zhuǎn),也可能以空間中的某條直線為軸進(jìn)行旋轉(zhuǎn),無 論那種旋轉(zhuǎn)方式,原理相同。 在二維平面坐標(biāo)系中,齊次矩陣可用 3? 3 變換矩陣來表示二維平面幾何變換,可知,在三維空間齊次坐標(biāo)系中用 4? 4 變換矩陣來表示三維幾何變換。 點(diǎn)云預(yù)處理 三維變換是點(diǎn)云預(yù)處理中最基本的方法,通常對點(diǎn)云數(shù)據(jù)進(jìn)行旋轉(zhuǎn) 、縮放、平移、濾波、平滑和分割與邊緣檢測等相應(yīng)處理,這與圖像變換處理本質(zhì)相同。填充空缺值、識別或移除孤立點(diǎn)、平滑噪聲和解決數(shù)據(jù)之間不一致性是數(shù)據(jù)清理的目的。所以,對點(diǎn)云構(gòu)建三角網(wǎng)模型逼近實(shí)物 是常用的表面模型重建方法。 167。 點(diǎn)云數(shù)據(jù)表示方法 三維激光掃描數(shù)據(jù)的數(shù)學(xué)表達(dá)式表示方法如下 [11]: }1...2101...210),({ ????? YnXmnmPM ,, (24) 其 中,點(diǎn)集 M 為所獲取的點(diǎn)云集合, X 表示為掃描點(diǎn)對應(yīng)的矩形空間行數(shù), Y 表示掃描點(diǎn)對應(yīng)的矩形空間列數(shù), m 、 n 分別為該點(diǎn)在矩形空間的行、列索引值, ),(),( zyxnmp ?表示該點(diǎn)的距離信息也就獲取點(diǎn)數(shù)據(jù)的空間坐標(biāo)值。 2. 視點(diǎn) (Viewpoint) 引入視點(diǎn)的概念是為更好的描述三維激光掃描儀在每個(gè)掃描位置上獲取的不同掃描結(jié)果。該軟件具有耗時(shí)短,精確度高等優(yōu)點(diǎn),因此a b 中國地質(zhì)大學(xué)碩士學(xué)位論文 11 廣泛應(yīng)用于點(diǎn)云數(shù)據(jù)的三維模型重建領(lǐng)域。 Riegl VZ— 400 型三維激光掃描儀電子掃描探測器(圖 26 a 中結(jié)構(gòu)①),這樣設(shè)計(jì),不但使儀器體積小巧,而且可以提高儀器掃描速度。 H: 40176。 V: 270176。 lmm 采樣率 8000P/S 1000P/S 5000P/S 4400P/S 2020P/S 1500P/S 測 角 精 度 176。其缺點(diǎn):若將相機(jī)與掃描儀分開,使用前則需相機(jī)與激光掃描儀做聯(lián)機(jī)標(biāo)定和校對,才能確保點(diǎn)云涂色與紋理映射的精度,如表 21 所述常見的三維激光掃描系統(tǒng)參數(shù)。 圖 25 采用脈沖測距法的三維激光點(diǎn)坐標(biāo) 由幾何關(guān)系可得到三維激光腳點(diǎn)坐標(biāo)計(jì)算公式如式( 23)?;谙辔粶y量原理如 圖 24 所示 。 它適用于近距離測程范圍為 幾米到幾十米,主要用于逆向工程重建和工業(yè)測量,可以達(dá)到亞毫米級的精度。通過發(fā)射和接收激光脈沖時(shí)間差解算出被測場景與三維激光掃描儀內(nèi)部中心的距離,其測距公式為 (21)式。自本世紀(jì)初,多種表面三維掃描方法應(yīng)運(yùn)而生,總體而言,三維掃描儀的掃描方法可分為非接觸式和接觸式兩大類。 第五 章:三維模型重建。介紹了論文的選題背景、選題目的及意義,回顧三維激光掃描重建技術(shù)的國內(nèi)外研究現(xiàn)狀,對已有研究的分析與總結(jié),給出了本文的研究目標(biāo)與主要內(nèi)容,最后介紹了本文的結(jié)構(gòu)與安排。因此,點(diǎn)云數(shù)據(jù)處理和點(diǎn)云數(shù)據(jù)構(gòu)造三維模型是本文研究的重點(diǎn) 。 存在問題 自三維激光掃描技術(shù)誕生至今已有二十余年歷史,國內(nèi)外相關(guān)學(xué)者在三維激光掃描重建技術(shù)領(lǐng)域展開了深入的研究,取得了矚目的成果,但也存在如下問題: 1. 點(diǎn)云 數(shù)據(jù)量大 是三維激光掃描重建技術(shù)的瓶頸問題之一。加拿大 NRC(加拿大國家研究委員會 )的 EIHakiml[6]等人對 CCD 照相機(jī)和激光掃描儀重新組裝,使用自己的硬件平臺,制作三維建模系統(tǒng) [7]。三維激光掃描技術(shù)在三維重建領(lǐng)域的應(yīng)用具有重大的現(xiàn)實(shí)和歷史意義,能夠在不接觸真實(shí)實(shí)體而記錄實(shí)物信息,快速再現(xiàn)物體原貌。隨著科學(xué)技術(shù)的不斷發(fā)展,基于三維激光數(shù)據(jù)的重建技術(shù)將在更多領(lǐng)域得到廣泛應(yīng)用,同時(shí)也將成為諸多學(xué)者研究的熱點(diǎn)。利用這些三維模型,為文物修復(fù)和復(fù)制帶來便利。十年前,因科技發(fā)展的限制,二維數(shù)據(jù)是重建數(shù)據(jù)的主要數(shù)據(jù)源,如 CCD 傳感器、錄相設(shè)備、平面掃描設(shè)備、照相機(jī)等。 基于點(diǎn)云數(shù)據(jù)的三維模型重建 ........................................... 44 Delaunay 三角剖分 .................................................. 44 Voronoi 圖 .................................................... 44 三角剖分和 Delaunay 三角剖分定義 ............................... 45 Delaunay 三角剖分特性 ......................................... 45 構(gòu)網(wǎng)實(shí)現(xiàn)方法 ...................................................... 46 167。 介紹 ................................................................ 27 167。 本文研究目標(biāo)與主要內(nèi)容 ................................................ 3 167。所以本文在給出初始位姿的基礎(chǔ)上,提出基于間接平差的 ICP 算法,這樣不但可以保障 ICP 算法全局收斂,而且可以減少算法耗時(shí),提高算法效率,優(yōu)化傳統(tǒng) ICP 算法。該技術(shù) 優(yōu)點(diǎn)是:掃描數(shù)據(jù)量大,掃描精度高,數(shù)據(jù)采集速度快、實(shí)時(shí)性強(qiáng)、主動性強(qiáng),不受時(shí)間與空間影響,能全天候工作。 本人所呈交的碩士學(xué)位論文沒有違反學(xué)術(shù)道德和學(xué)術(shù)規(guī)范,沒有侵權(quán)行為,并愿意承擔(dān)由此而產(chǎn)生的法律責(zé)任和法律后果。 本文利用三維激光掃描儀對中國地質(zhì)大學(xué)化石林中的化石進(jìn)行數(shù)字化掃描,重點(diǎn)研究工程應(yīng)用中多視點(diǎn)深度數(shù)據(jù)配準(zhǔn)方案以及模型構(gòu)建兩項(xiàng)關(guān)鍵技術(shù)。 ……………………………… . 關(guān)鍵詞:三維重建、點(diǎn)云、配準(zhǔn)、三維模型 The Reseach of 3D Reconstruction from Laser Scan Data Master Candidate: Yu Mingxu Supervisor: Prof. Xiuguo Liu ABSTRACT With the development of science and technology, the methods and means of measurement which is from the ancient tools such as string and ruler to 3D Laser Mapping system, changing every day, the 3D Laser Scanning technology is the hundredpercent leading one in surveying and mapping domain after GPS technology. Its advantages include large scale of data, high precision, fast collection of data, the ability of realtime, pletely driven by itself and no matter the temporal and spatial restrains, it works all the time. Compared with conventional touching measurement, it can collect the surface information of the objects without any contact, the existence of highdensity scanning data of surface information is called “Points Cloud”. Reflecting on the clouding point, it is an absolute hightech way which can indicate the general situation objectively and really for reconstructing the real world with 3D model. With the rapid development of 3D Laser Scanning technology and its interrelated data processing, the extensive prospect, in Reverse Engineering, Protection of cultural relics, Pattern Recognition and Digital Recreation and so on, are taken into consideration. As for this paper, we introduce the native and foreign public understanding about 3D Laser Scanning technology at first and sum up its characteristics and application domain for explaining the working principle simply and classifying the kinds of hardware device. Secondly, introducing the RIEGL Laser Scanning system and RISCA PRO software, and then presenting the preprocessing of points cloud for scanning data and search a method to reconstruction by Geomagic Studio software which include 3D surface modeling, mending model hole and fitting the surface. This paper utilizes 3D laser scanner to scan digital the fossil in China University of Geosciences fossil forest, and focuses on deep data registration which is based on multiviewpoint and model building. Below is the main work of the paper. According to the features of laser scanning data, the paper introduces the characteristic of percise registration of ICP algorithm based on coarse registration, If the initial pose do not choose accurate in ICP algorithm, ICP algorithm is likely to fall into the local convergence, rather than the overall convergence. So in this paper, the indirect adjustment of the ICP algorithm was proposed based on the initial pose. That not only can guarantee the global convergence, but also can reduce timeconsuming, It is improvement and optimization traditional ICP algorithm. The laser scan data can reconstruct after Points Clound registration. Currently, the methods of 3D reconstruction mostly base on Delaunay Triangulation, so this paper attempts to rebuild Delaunay Triangulation to reconstruct 3D surface models, then I use Geomagic Studio 10 software and manmachine interactive to reconstructe 3D model with Points Clound . Based on the above method, the paper takes fossil as scanning object, and tests on its scanning data. The experiment result proves that we have got goal on Poin
點(diǎn)擊復(fù)制文檔內(nèi)容
環(huán)評公示相關(guān)推薦
文庫吧 www.dybbs8.com
備案圖鄂ICP備17016276號-1