投影

In order to reduce the effect of imaging recognition error, the recognition location of projection is extended and refined, and the projection edge of sphere centre is implanted. So a pyramid is formed by radial line between the camera optical centre and the implanted point. A curved face is formed by the two pyramids and barbette sphere. To calculate the shape centre of the common section of the curved face, the shape centre is the coordinate of sphere centre.

为了降低图像识别误差的影响，对投影的识别位置进行拓展和细化，并对球心投影边界进行插值，摄像机光心与插值点连线射线形成了一个锥体，两摄像机的锥体分别与炮台球面相交形成曲面，计算两曲面公共部分的形心，即为球心位置。

In this paper, according to the characteristics of central projection, aerial photographs were analyzed to discuss displacement of images under tilt conditin or caused by ground undulation, based on which the principles of tilt error and projection error were summarized.

根据中心投影的特性，论述了像片在倾斜条件下所引起的像点位移和像片因地面起伏而引起的像点位移，在对其进行分析的基础上总结出倾斜误差和投影误差的规律，从而说明了不能把像片当作地形图使用。

In this paper, according to the characteristics of central projection, aerial photograph s were analyzed to discuss displacement of images under tilt conditin or caused by ground undulation, based on which the principles of tilt error and projection error were summarized.

本文以航空摄影测量像片为分析对象。根据中心投影的特性，论述了像片在倾斜条件下所引起的像点位移和像片因地面起伏而引起的像点位移，在对其进行分析的基础上总结出倾斜误差和投影误差的规律，从而说明了不能把像片当作地形图使用。这是使用航空像片时必须注意的基本问

According to the characteristics of the gray projection curves, a pair of maximum and minimum points are found near the central position of each gray projection curve. The differences in position are calculated respectively and the scale change parameter is obtained as the ratio of both differences.

此时，可根据尺度变化下图像灰度累积投影曲线的特点，分别计算参考帧和当前帧的投影曲线上一对极大—极小值点的坐标差值，以它们的比值作为缩放系数，实现实时求取。

By taking advantage of a corollary of the Desargues theorem and the corresponging extension of Desarguesian configuration, the concept of stereohomology has been defined in projective geometry and presented based on homogeneous coordinates. Consequently, a series of geometrical transformations, such as central projection, parallel projection, centrosymmetry, translation transformation, reflection, rotation transformation, which can be contained in it or derived from it have also been analytically defined.

利用Desargues定理的一个推论和引申的Desargues图形，给出"空间透射"在射影几何意义下基于齐次坐标表象的解析定义，从而解析定义了可蕴涵其中的中心投影、平行投影、中心对称、平移、反射等几何变换以及可由此衍生出的旋转变换。

Combined with engineering applications,the method directly utilizes rectangular information of the scene and the centrical projection relation of the point to obtain the projection relation of the lines.

本方法结合工程应用实际，直接利用场景的直角信息，根据点的中心投影关系，推导直线的投影关系，基于平面上不平行的3条直线，由单幅图像线性的高精度的标定出摄像机内、外参数。

First, a special normal transversal at the initial point is constructed and a second-order Taylor's algorithm is used to trace the projections along the aforementioned normal transversal. A curvature based method for controlling iteration step is further proposed by projecting the given point onto the curvature circle of the normal transversal at the initial point. Finally gradient based method for correcting iteration errors is put forward.

首先构造初始点处的一条特殊的法截线，并给出沿着该法截线追踪投影点的二阶泰勒迭代方法；然后将给定点向初始点处的法截线的曲率圆作投影，提出基于曲率的步长控制策略，在此基础上给出了基于梯度的迭代误差矫正方法。

By analytic geometry method and solving quadratic equation,a computer simulation algorithm of digital projection under arbitrary scanning locus was proposed.The algorithm is based on the rules of attenuation of monochromatic X-rays.Through mathematical modeling and computer simulation,digital projections of ellipsoid and cylinder in circular and helix scanning modes are exemplified respectively,which are proved to be correct by FDK and PI-line reconstruction algorithms.

介绍了一种利用解析几何和求解二次方程仿真任意扫描轨迹下的锥束射线投影数据算法，该方法基于单色射线贯穿物体的衰减理论，通过数学建模与计算机仿真，给出了椭球、圆柱两种典型模型分别在单圆、螺旋线扫描轨迹下的投影数据仿真结果，并利用FDK和PI线重建算法进行验证，证明了该种数值仿真方法的正确性。

In this paper, the theory and method of polynomials for conformal projection transformation and their application in CAC and in the construction of GIS are systematically discussed. Also introduced is the programme package in BASIC and FORTRAN for conformal projection transformation.

本文系统地讨论了等角投影变换的正形变换多项式的理论、方法及其在计算机制图和地理信息系统建设中的若干应用问题，并同时介绍了《等角投影变换BASIC、FORTRAN程序软件包》的有关内容。

Firstly, by using the function of EXCEL software and choosing the appropriate expression to calculate and get positive axis single latitude conic projection plane right-angle coordinates data table and length distortion data table about latitude.

根据实践经验，以经度97°~108°；纬度23°~34°为研究工区，用正轴切圆锥投影模型为例，介绍利用EXCEL软件中的公式对地图制图中的数据进行运算处理，求得正轴单纬圆锥投影平面直角坐标数据表，以及长度变形随纬度变化的关系数据表。

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。