We address the problem of feature correspondences in images of coplanar ellipses with objective to benefit of robust ellipse fitting algorithm. The main difficulty is the lack of projective invariant points immediately available. Therefore, our key idea is to construct virtual line and point features using the property of tangent invariance under perspective projection. The proposed method requ...

We develop a number of space-efficient tools including an approach to simulate divide-and-conquer space-efficiently, stably selecting and unselecting a subset from a sorted set, and computing the kth smallest element in one dimension from a multi-dimensional set that is sorted in another dimension. We then apply these tools to solve several geometric problems that have solutions using some form...

Presented in this paper is an algorithm to compute the intersections of a parametric regular surface with a set of parallel planes. Rather than using an ordinary surface-plane intersection algorithm repeatedly, we pre-process a surface to identify points, called topology transition points (TTP's), on the surface where the topologies of intersection curves change. It turns out that such points c...

This paper aim to create method observe elevation of points, tower and structure that can’t be reach (or don’t need reach), this depend on concept space intersection where intersect two known direction vectors start from location points or can located simple computation. discuss too accuracy improvement for observed by above method.

Many geometric algorithms that are usually formulated for points and segments generalize easily to inputs also containing rays and lines. The sweep algorithm for segment intersection is a prototypical example. Implementations of such algorithms do, in general, not extend easily. For example, segment endpoints cause events in sweep line algorithms, but lines have no endpoints. We describe a gene...

We prove that if X,X are closed subschemes of a torus T over a non-Archimedean field K, of complementary codimension and with finite intersection, then the stable tropical intersection along a (possibly positive-dimensional, possibly unbounded) connected component C of Trop(X) ∩ Trop(X) lifts to algebraic intersection points, with multiplicities. This theorem requires potentially passing to a s...