quadtree 中文意思是什麼

The techniques related terrain lod is systematically studied based on the quadtree data structure. combining the data block attemperation idea, we solved the data integrating and preculling problem, presented the boundary constraining solution, and calculated the collision detection for rambling

本文在四叉樹結構的基礎上較為系統的研究了地形相關lod技術，結合數據分塊調度思想，解決了數據連接和預裁剪問題，給出了邊界約束問題的解法，並針對漫遊計算了特定的碰撞檢測。

Framed - quadtree approach not only guarantees the connectivity of environment structure model, but also deal with complex terrain instances and truly reflects terrain detail color

賦值外框四叉樹方法不僅保證了環境構造圖的連通性，而且可以處理地形中復雜情況並比較真實地反映地形的細節面貌。

The famous algorithms include roam, vdpm, adaptive triangulation based quadtree and the improved algorithms of them, etc. however, the improvement of the present algorithms mainly focus on the selection of data structure which can speed up generation of the tmrm, few works were put into ameliorating the simplification criterion, hi fact, the simplification criterions used by the algorithms at present are constructed with only two elements which are the distance the vertex from the viewpoint and the roughness of terrain expressed by z coordinate

地形多解析度模型的生成演算法種類較多，著名的有：自適應優化格網演算法（ roam ） 、基於視點的累進格網法（ vdpm ） ，基於四叉樹的自適應剖分演算法以及基於各演算法的各種改進演算法等等。但目前人們對演算法的更新及改進主要是從數據結構的角度來考慮，對簡化準則沒有做實質性的改進。

A digital image watermarking algorithm based on quadtree and error correcting code

基於四叉樹和糾錯編碼的數字圖像水印演算法

Secure multimedia encoding schemes based on quadtree structure

基於四叉樹的多媒體安全編碼方案

Integrated with present meshing techniques of quadtree and template, a new mesh generating method is proposed and designed which is based on the mapping method

將四叉樹法和模板法相結合，在映射法的基礎上設計並實現了一種新的網格劃分方法。

Wavelet video coding ; embedded coding ; quadtree coding

小波視頻編碼嵌入式編碼四叉樹編碼

Establishing 3 - d terrain models with vector contour lines and elevation terrain models with the help of the determination of space corresponding relations between contour lines, tile operation and branch operation. explanation of real - time reflection of terrain models, including three algorithms in lod technology, compared with quadtree algorithm, roam algorithm and the algorithm based on the intermediate belt, to show the advantages and disadvantages of the different situations of the terrains, so as to find out the right algorithm, the quadtree algorithm. developing and implementing the fast demonstration on the vc platform with three - dimentional visualization techniques, such as vrml and opengl, providing a persuasive argument for the research

論文首先概括介紹了用等高線快速建立3d地面模型和顯示的相關技術，並論述了課題研究的背景和選題依據;其次，論文闡述了如何對等高線數據進行預處理，提出了有效的得到矢量化等高線的方法;再次用矢量化的等高線數據建立三維地面模型，通過等高線間的對應關系的確定、瓦片操作、分支操作建立地面的高程模型;然後論文對地面模型的實時渲染問題進行了深入闡述，主要是從lod技術的三種演算法著手進行研究，通過對比四叉樹演算法、 roam演算法和基於過渡帶演算法對不同種情況的地面數據顯示的優缺點，再結合本系統的地形數據的特點選擇了適合的演算法:四叉樹演算法;最後，用vrml和基於opengl的三維可視化技術在vc平臺上開發並實現了地形的三維快速顯示系統，為論文的研究內容提供了有力的論證。

Integrating with the continuous level of detail of geometry mesh, we present an criteria for selecting an appropriate node on the texture the quadtree, and rendering the mesh with the corresponding quadtree texture

紋理組織方式有效地匹配于地形幾何的連續層次多分辨細節模型，提出了紋理四叉樹的多解析度選取策略，並從紋理結點出發，繪制幾何網格。

Compression coding for multi - gray image based on quadtree

基於四叉樹的多灰度級圖像壓縮編碼方法研究

Motion compensated prediction error image has significant amplitudes mainly along the boundaries of moving objects, correspondingly its wavelet coefficients contain large energy in high frequency bands. this greatly reduces the coding efficiency of ezw. it is first provided that the correspondence between the significant amplitudes area of the mcp error image and the wavelet coefficient significant map, then encode the significant map efficiently using quadtree approach, followed by bit - plane coding the significant coefficients to produce an embedded data stream. experiment result shows that compared to ezw and zte, the proposed algorithm is more efficient and has better performance

演算法對于運動補償余量誤差幀首先進行小波變換，並選取適當的閾值，用重要圖表示大於該閾值的重要系數。根據殘差幀小波系數的統計特性，用四叉樹方法編碼重要圖，並對重要系數作位面編碼，生成嵌入式碼流。實驗表明，與ezw ， zte等演算法相比較，該演算法編碼效率高，復現圖像質量好。

The texture data are organized in a quadtree as a bandwidth - limited resource rather than a finite resource

在有限的紋理存儲資源下，使川了基於四叉樹的多解析度表示方式。

Based on the coding, the algorithm for neighbor searching in leaf - coding quadtree was implemented

此方法減少了四叉樹存儲的結點個數，提高了存儲效率。

The results of this paper are of great significance to the auv s autonomous navigation and application of data structure of quadtree and octree

本論文對于智能水下機器人自主導航的研究和研究四叉樹、八叉樹數據結構的應用有重要意義。

A quadtree method for fractal image coding

分形圖像編碼的四叉樹方法

Real - time generation of dynamic terrain based on adaptive quadtree

基於自適應四叉樹的實時動態地形生成

An embedded wavelet quadtree interframe coding algorithm an embedded wavelet quadtree interframe coding algorithm

一種嵌入式小波四叉樹幀間編碼演算法

Self - adapted quadtree image compression method proposed by fisher [ 13 ] in - creases the speed of encoding procedure of the image, heightens the compression ratio, but the quality of the reconstructed image is not good

Fisher提出的自適應四叉樹編碼方法加快了圖象編碼的速度，提高了圖象的壓縮比，但是在圖象的重建質量上還存在不足。

Then, in the second chapter, we generalize the mathematical principle of fractal image compression. in the third chapter, we introduce jacquin ' s fractal image compres - sion method and fisher ' s self - adapted quadtree image compression method

第二章給出了分形壓縮編碼的數學原理和理論基礎。第三章介紹了jacquin的分形壓縮編碼方法和fisher的自適應四叉樹編碼方法。

On the basis of the new affine transformation and self - adapted quadtree im - age compression method, we bring forward a new image compression method. experiments show that the psnr can reach 28. 7db at the compression ratio of 22. 4 for 256 x 256 x 8 " lena " image, better than jacquin [ 1 ], fisher [ 13 ] and yao zhao [ 12 ] ' s method. at last, we point out the defects of the method and program, bring forward some ways to be improved

並介紹了用此演算法編寫的程序，給出了實驗結果，實驗結果顯示「 lena 」 256 256 8圖象在psnr等於28 . 7時，壓縮比可以達到22 . 4 ，比fisher ， jacquin ，和趙耀等人的結果都有一定程度的改進，文章最後指出了演算法和程序的不足，提出了一些改進的方向。