1) circular arc projection method
圆弧投影法
1.
This paper proposes the circular arc projection method for drawing intersection lines of some objects with curved surface, which would sometimes be more convenient than orthogonal projection method for doing the same thing.
本文提出了利用圆弧投影法,求某些曲面立体的相贯线的作图方法,这种方法有时比正投影法更为方便。
2) circular projection
圆弧投影
1.
This paper applies the principle of circular projection in finding intersection points between lines and revolved surfaces, with the intersecting problem of the line and the surface in 3D space converted to that of a hyperbola and a surface s contour line in 2D plane.
本文将工程图学中的圆弧投影原理应用于直线与回转面的交点计算 ,把空间线面的求交问题转化为平面上二次曲线与回转面轮廓线的求交 ,不仅提高了计算效率 ,而且几何意义清楚 ,算法可靠 ,对于无交点和多交点的情况能够一次判别出
3) projection method for a part of circle
圆弧投射法
1.
This paper introduces the elements of projection method for a part of circle,especially for a round,and gives an example to explain the use of the projection method for a part of circle in seeking the especial points on conterminous line.
介绍圆弧投射法的原理 ,特别是圆的圆弧投影 ,并举例说明了圆弧投射法在求相贯线上特殊点中的应用。
4) the method of isometric cone projection
等角圆锥投影法
1.
The errors of the method of isometric cone projection that is widely adopted by people are analyzed, and the distance error and angle error are obtained for the application in engineering.
本文对较为广泛被人们接受的一种地图投影方法—等角圆锥投影法的误差进行了分析,给出在不同距离内采用等角圆锥投影方法的距离误差和方向角误差,以便在实际应用中有选择使用。
5) point to arc projection extremum method
点弧线投影极值法
6) Projection round
投影圆
补充资料：滤波反投影或卷积反投影
滤波反投影或卷积反投影
影像学术语。当代影像学设备进行影像重建的数学方法。在直接用扫描后所获得的投影轨迹剖面图反投影重建出的CT图像中，无法避免角度卷入条纹伪影(angular aliasing streaks)造成的模糊和失真。这种现象与被扫描层面的空间频率中高频信息的损失有关。使用一种精密的数学方法去除这种模糊。称为“展现”(unfolding)或去卷积(deconvolution)，即在反投影前使用一种数学的“滤器”或卷积函数对原始数据进行修正，然后再进行反投影。两步数学处理过程合称为滤波(修正后)反投影或卷积(后)反投影。这种方法的优点是处理过程简单，速度快，所得图像逼真、清晰。
说明：补充资料仅用于学习参考，请勿用于其它任何用途。
参考词条