In order to satisfy the demand of data i / o in real time when scene rendered , partition and process of the spatial data according to different detail criterion should be done , and with the help of a nested index structure , the scene pyramid + sub scene regular dividing quad - tree , spatial data of a 3d scene is organized into a multi - level of detail pagoda structure 本文提出通过对空间数据按照不同区域、不同细节层次进行分割加工，利用场景金字塔+子场景地物的规则划分四叉树索引结构，将三维场景的空间数据组织成多细节层次的塔型结构，以有效支持后续的数据调度策略以及绘制过程的优化，满足大规模场景实时绘制的需要。
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 算法对于运动补偿余量误差帧首先进行小波变换，并选取适当的阈值，用重要图表示大于该阈值的重要系数。根据残差帧小波系数的统计特性，用四叉树方法编码重要图，并对重要系数作位面编码，生成嵌入式码流。实验表明，与ezw ， zte等算法相比较，该算法编码效率高，复现图像质量好。
Based on the characteristic of wavelet and fractal an algorithm of image compression using wavelet transform and fractal quadtree is presented . this algorithm combine time domain ' s fractal quadtree compression method with wavelet transform compression method . the results show that the algorithm approach might be able to improve vision effection because wavelet transform is used to enhance image ' s self - similar used by fractal method 在基于小波变换的图像压缩研究中首先提出一种将神经网络、矢量量化相结合的小波域图像压缩算法，然后又提出一种基于四叉树的小波域分形图像压缩算法，将时域四叉树分形压缩算法与小波域小波树压缩算法相结合，充分利用两者的优点，减少了通常图像由于自相似性不强而存在的分形压缩效果不佳的现象。
We first put forward the file system of hierarchy structure through an object - oriented programming approach . to deal with great amount of data from geographic information and the need of fast access , we design a kind of professional embedded gis data structure to combine the quad tree storage format and the deploying mode of the file system . this method can implement the fast access for geographic information data 通过面向对象的程序设计方法提出层次体系架构的文件系统；并针对地理信息数据量大的特点和快速空间存储的需求，提出了一种将四叉树存储格式与文件系统的调度方式相结合的嵌入式gis专用数据结构，实现了地理信息的快速存取。
Furthermore , good compression effectivity is presented in application to compression of pd gray intensity images . according to the research on difference degree between computational values of fractal features extracted from decoded pd images and that from original images , it is shown elementarily that the proposed method is effective for application in pd pattern auto - recognition system . ( 4 ) this paper brings forward pd pattern auto - recognition project based on the above recognition features and fractal compression of pd gray intensity images and designs the classifier with back - propagation neural network ( bpnn ) ( 3 )研究了局部放电灰度图像的四叉树分形图像压缩方法，通过仿真实验证明采用本文算法能够获得一定的图像压缩比，在局部放电灰度图像压缩应用中显示了良好的压缩效果，进一步研究了局部放电解码图像的识别结果与原始图像之结果的差异程度，研究结果初步表明该方法应用于局部放电模式自动识别系统中是有效的； ( 4 )研究了基于局部放电解码图像的bpnn识别方法及，通过分析对解码图像的识别效果，验证了设计的系统模式识别方案的有效性，同时表明该方案能够满足实地局部放电模式自动识别和远程数据通讯及自动识别的需要。
In the case of data index , the paper generalizes several advanced data index at the present time and analyzes the feature of data index based on database emphatically . then it illustrates the spatial ordering quad - tree index based on database of gde . in the case of geographic data management , the paper studies and tests several primary technologies , such as data concurrent access , data storage , data query , data update and maintenance , data transmission and data buffer , and so on 数据模型方面，在对常见的数据模型进行描述和分析的基础上，提出了满足海量数据高效存储和管理的gde数据模型，通过实验对数据的存放方式和效率进行了测试；数据索引方面，归纳总结了当前提出的较为先进的几种数据索引方法，尤其是着重分析了基于数据库的数据索引的特点，并对gde基于数据库的可排序四叉树索引进行了重点阐述；地理数据管理方面，对数据并发访问、数据查询、数据更新与维护、数据传输以及数据缓存等关键技术进行了阐述和实践；地理数据访问对象方面，介绍了采用面向对象技术设计实现的地理数据访问类。
