投影

After certifying the irreality of ideal filtering function, we can get a better filter selecting a proper window function. Comparing two actual filters, we designate a good"Panama hat"filtering function. Meanwhile, an effectively linear interpolating function is introduced to raise the image reconstruction quality. Describing its realizing steps on the micro-computer briefly, we reconstructed some images from the anlogue projections of some models. The number of projection views is 180, 100 same interval parallel lines per view; the size of reconstructed images is 64×64 pixels with 64 gray levels; the reconstructing speeds are 40" on PC-386 and 12"on PC-486, respectively; each pixel is 0.31mm.

在证明了理想滤波器的不可实现性之后，得知通过选择适当的窗函数可获得很好的滤波函数，经过两个实际滤波器的效果对比，我们选取了较好的"巴拿马帽"形滤波函数，同时也介绍了一个有效的提高重建质量的线性内插函数，概要地叙述了平行射束图象重建的计算机具体实现步骤后，对几个物体的模拟投影数据进行了重建：投影角为180°，每视角下有100个平行投影数据点，在386微机上重建尺寸为64×64，时间约为40秒；在486/33MHz微机上只用了12秒，图象的象点精度是0.31mm。

Isometric projection , a species of orthographic projection, in which but a single plane of projection is used.

正规投影正交投影的一种，通常用在单一平面的投影上。

The simulation result shows the collection efficiency of TIR lens model is 67% when the angle of light is confined within 15°. And the uniformity on observation screen is improved in some degree. The optimal design of TIR lens further provides the development space of LED micro-projection display system.4 On the base of the theory research and the model simulation, four projection display systems which have LCOS as micro-display panel and which combine different optical devise for UHP and LED light source respectively are proposed in this dissertation. And the quality of projection display system is evaluated by thesimulation outcome.

模拟结果表明，优化后的TIR透镜可实现将LED大角度扩展光束中67％的光能压缩到15°范围以内，并使目标屏的照明均匀性得到一定的改善，这为LED光源微投影显示系统设计提供了新的发展空间。4在以上理论研究和模拟分析的基础上，将优化和改造得到的照明光学元件应用到微投影显示的照明系统设计中，分别采用UHP和LED光源，设计了四套单片式LCOS微投影显示系统模型，通过光线追迹模拟结果，对系统性能进行了评价分析和对比。

Digital light processing technology is a key branch of projection display, and the technology based on light emitting diode is an important development direction of DLP technology.

数字光源处理投影技术是投影显示的一个重要分支，基于发光二极管照明技术的DLP投影显示技术则是目前DLP技术的一个重要发展方向。

Map projection ; inverse transformation ; map projection system ; map projection parameters ; algorithm optimization ; error control

地图投影；反解变换；投影体系；投影参数；算法优化；误差控制

The projection on its orthogonal plane converges to a line and shows the oblique angles between two other projection planes.

在所垂直的投影面上的投影积聚为直线，反映与另二投影面的倾角。

This approach utilizes the fact that if the centerline of target image gets through the center point of the image plane,perspective projection and parallel projection must have the same image-forming property.

依据在目标成像的中轴线通过像面中心的时候，平行投影法和透视投影法有相同的成像特征这一事实，提出了一种无模型误差的修正平行投影法。

Each other, it is called parallel projection.

平行投影法投射线互相平行的投影法称为平行投影法。

Give a projecting plane,sign volume of pentahedron for each triangle in mesh,which is constructed by the triangle and it projection in projecting plane,is computed.Volume of the mesh is algebraic sum of all pentahedrons' signed volume.Triangles will be partition into several smaller triangles when necessary.

该方法通过指定投影平面，计算每个三角面片及其在投影平面上的投影所围成的凸五面体的带符号体积（必要时对三角面片进行细分），整个模型的体积为所有凸五面体带符号体积的代数和。

The modelview transform is used in the same way as it is in the OpenGL viewing pipeline, to move the viewer to the origin and the projection centered along the negative z axis. In this case, viewer can be thought of a light source, and the near clipping plane of the projection as the location of the texture image, which can be thought of as printed on a transparent film.

模型/视图变换的作用和它在OpenGL 观察管道里的作用是一样的，它将观察者沿-Z方向移动到原点和投影中心，在这种情况下，观察者就好比是是光源，近裁剪平面好比是需要投影的纹理图象的所处的位置，纹理图象可以被看作一个在投影的透明胶片。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。