This paper describes a method of automated type and pose (position and orientation) identification of partially exposed metal objects that makes excavation of hazardous materials safe and efficient. The object pose is estimated by matching a model of the object to the area that is extracted from the range image using the characteristics of metal objects. Experimental results show feasibility of...

Corners and curves are important image features in many vision-based applications. Corners are usually more stable and easier to match than curves,while curves contain richer information of scene structure. In previously work, corners are often used to recover the epipolar geometry between two views, which is then used in curve matching to reduce the search space. However, information of the sc...

This paper presents a new curve matching method for deformable shapes using two-dimensional splines. In contrast to the residual error criterion [7], which is based on relative locations of corresponding knot points such that is reliable primarily for dense point sets, we use deformation energy of thin-plate-spline mapping between sparse knot points and normalized local curvature information. T...

Vandalism is a type of the so-called low intensity crimes. However, the nuisance and damage caused by it could cost dearly to the public to clean up. It is also technically difficult in the past to detect and prosecute such a crime, for example, graffiti making. This paper presents an automatic and live graffiti detection system using CCTV cameras and innovative vision algorithms. After a brief...

In the recent years, Riemannian shape analysis of curves and surfaces has found several applications in medical image analysis. In this paper we present a numerical discretization of second order Sobolev metrics on the space of regular curves in Euclidean space. This class of metrics has several desirable mathematical properties. We propose numerical solutions for the initial and boundary value...

The process of un-reduction, a sort of reversal of reduction by the Lie group symmetries of a variational problem, is explored in the setting of field theories. This process is applied to the problem of curve matching in the plane, when the curves depend on more than one independent variable. This situation occurs in a variety of instances such as matching of surfaces or comparison of evolution...

Curve matching is a fundamental problem which occurs in many applications. In this paper, we extend the Fréchet distance to measure partial curve similarity, study its properties, and develop efficient algorithms to compute it. In particular, under the L1 or L∞ metrics, we present an algorithm to compute, in O(m2) time, the partial Fréchet distance between a segment and a polygonal curve of siz...

Common techniques for curve alignment find a solution in the form of a shortest network path by means of dynamic programming. In this paper we present an approach that employs Sethian’s Fast Marching Method to find the solution with sub-resolution accuracy and in consistence with the underlying continuous problem. We demonstrate how the method may be applied to compare closed curves, morph one ...

We address the general practical problem of determining correspondences between maps and terrain images, and focus on a static low altitude airborne scenario. For this case we consider the approach of partially matching detected and expected curves in the image plane. Expected curves are generated from a map, using an estimate of the sensor pose in three dimensions, and matched with simulated d...

Let P be a polygonal curve in R of length n, and S be a point set of size k. We consider the problem of finding a polygonal curve Q on S such that all points in S are visited and the Fréchet distance between Q and P is at most a given ε. We show that this problem is NP-complete, regardless of whether or not the points of S are allowed to be visited more than once.