Topic
Winged edge
About: Winged edge is a research topic. Over the lifetime, 67 publications have been published within this topic receiving 2778 citations.
Papers published on a yearly basis
Papers
TL;DR: A mechanism is presented for automatic selection of scale levels when detecting one-dimensional image features, such as edges and ridges, with characteristic property that the selected scales on a scale-space ridge instead reflect the width of the ridge.
Abstract: When computing descriptors of image data, the type of information that can be extracted may be strongly dependent on the scales at which the image operators are applied. This article presents a systematic methodology for addressing this problem. A mechanism is presented for automatic selection of scale levels when detecting one-dimensional image features, such as edges and ridges.
A novel concept of a scale-space edge is introduced, defined as a connected set of points in scale-space at which: (i) the gradient magnitude assumes a local maximum in the gradient direction, and (ii) a normalized measure of the strength of the edge response is locally maximal over scales. An important consequence of this definition is that it allows the scale levels to vary along the edge. Two specific measures of edge strength are analyzed in detail, the gradient magnitude and a differential expression derived from the third-order derivative in the gradient direction. For a certain way of normalizing these differential descriptors, by expressing them in terms of so-called γ-normalized derivatives, an immediate consequence of this definition is that the edge detector will adapt its scale levels to the local image structure. Specifically, sharp edges will be detected at fine scales so as to reduce the shape distortions due to scale-space smoothing, whereas sufficiently coarse scales will be selected at diffuse edges, such that an edge model is a valid abstraction of the intensity profile across the edge.
Since the scale-space edge is defined from the intersection of two zero-crossing surfaces in scale-space, the edges will by definition form closed curves. This simplifies selection of salient edges, and a novel significance measure is proposed, by integrating the edge strength along the edge. Moreover, the scale information associated with each edge provides useful clues to the physical nature of the edge.
With just slight modifications, similar ideas can be used for formulating ridge detectors with automatic selection, having the characteristic property that the selected scales on a scale-space ridge instead reflect the width of the ridge.
It is shown how the methodology can be implemented in terms of straightforward visual front-end operations, and the validity of the approach is supported by theoretical analysis as well as experiments on real-world and synthetic data.
1,060 citations
1 Oct 1972
TL;DR: A winged edge polyhedron representation is stated and a set of primitives that preserve Euler''s F-E+V = 2 equation are explained.
Abstract: A winged edge polyhedron representation is stated and a set of primitives that preserve Euler''s F-E+V = 2 equation are explained. Present use of this representation in artificial intelligence for computer graphics and world modeling is illustrated and its intended future application to computer vision is described.
396 citations
1 Jul 1983
TL;DR: The procedure for 2D-3D conversion provides a powerful new method for manual input of solid models, a common interface to all turnkey graphics systems, and, properly integrated with existing technology for scanning of drawings, a powerfulnew method for acquisition of CAD/CAM data bases from existing drawings.
Abstract: This paper describes the results of basic studies on procedures for creating solid models of component geometry from two-dimensional orthographic projections. An interactive graphic program was developed to allow the input of three orthographic views of a component geometry by digitizing from a drawing. The views may contain straight lines and circular arcs, solid or dashed. No restrictions are placed on the order or direction of lines and arcs in any view. Using an extension of the Wesley-Markowski procedure, the program constructs a three-dimensional solid model of the object. When the projections are ambiguous, multiple solid models are produced. The solid model may contain planar, cylindrical, conical, spherical and toroidal surfaces. Topological information of the solid model is stored in a winged edge structure. Geometric information is stored as vertex coordinates and surface equations.The procedure for 2D-3D conversion provides a powerful new method for manual input of solid models, a common interface to all turnkey graphics systems, and, properly integrated with existing technology for scanning of drawings, a powerful new method for acquisition of CAD/CAM data bases from existing drawings.The procedure is described, examples of typical input and output are shown, and possible extensions are discussed.
114 citations
5 Jan 2004
TL;DR: The preliminary results show that the method for decomposing an object represented in polygon meshes into components by means of critical points works effectively and efficiently and can be useful for applications such as 3D model retrieval and morphing.
Abstract: Polygon mesh is among the most common data structures used for representing objects in computer graphics. Unfortunately, a polygon mesh does not capture high-level structures, unlike a hierarchical model. In general, high-level abstractions are useful for managing data in applications. In this paper, we present a method for decomposing an object represented in polygon meshes into components by means of critical points. The method consists of steps to define the root vertex of the object, define a function on the polygon meshes, compute the geodesic tree and critical points, decide the decomposition order, and extract components using backwards flooding. We have implemented the method. The preliminary results show that it works effectively and efficiently. The decomposition results can be useful for applications such as 3D model retrieval and morphing.
58 citations
1 Jul 1982
TL;DR: This paper shows that the “wire frame” problem is equivalent to finding the embedding of a graph on a closed orientable surface, which satisfies all the topological properties of physical volumes.
Abstract: The design of complex geometric models has been and will continue to be one of the limiting factors in computer graphics. A careful enumeration of the properties of topologically correct models, so that they may be automatically enforced, can greatly speed this process. An example of the problems inherent in these methods is the “wire frame” problem, the automatic generation of a volume model from an edge-vertex graph. The solution to this problem has many useful applications in geometric modelling and scene recognition.This paper shows that the “wire frame” problem is equivalent to finding the embedding of a graph on a closed orientable surface. Such an embedding satisfies all the topological properties of physical volumes. Unfortunately graphical embeddings are not necessarily unique. But when we restrict the embedding surface so that it is equivalent to a sphere, and require that the input graph be three-connected, the resulting object is unique. Given these restrictions there exists a linear time algorithm to automatically convert the “wire frame” to the winged edge representation, a very powerful data structure. Applications of this algorithm are discussed and several examples shown.
56 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2017 | 1 |
| 2015 | 2 |
| 2013 | 4 |
| 2012 | 1 |
| 2011 | 2 |
| 2010 | 1 |