This paper proposes a solution to the problem of finding the boundary of the gamut of a color printing device or of a color image. A surface triangulation of a set of points in the color space is computed using an alpha-shape, which is a generalization of a convex hull applicable also to nonconvex solids. The desired level of detail can be controlled by means of an alpha parameter. A method for...

Alpha shapes have been conceived in 1981 as an attempt to define the shape of a finite set of point in the plane. Since then, connections to diverse areas in the sciences and engineering have developed, including to pattern recognition, digital shape sampling and processing, and structural molecular biology. This survey begins with a historical account and discusses geometric, algorithmic, topo...

Approximation is one of the key techniques used in manipulating geometric objects. Aggregation is a form of approximation that joins objects that are likely to be grouped together as a single unit. This can improve efficiency, reduce complexity and generate levels of detail, and has application in rendering, cartography and molecular structure design. In this work, we present a general framewor...

OBJECTIVE The purpose of this investigation was to evaluate the factor structure and the internal consistency of the Eating Disorder Examination-Questionnaire (EDE-Q). METHOD The EDE-Q was administered to 203 women with bulimic symptoms, who were recruited from five Midwestern communities. RESULTS Acceptable levels of internal consistency were observed for the EDE-Q total score (alpha = .90...

We present a system that allows new shapes to be created by blending between shapes taken from a database. We treat the shape as a composition of parts; blending is performed by recombining parts from different shapes according to constraints deduced by shape analysis. The analysis involves shape segmentation, contact analysis, and symmetry detection. The system can be used to rapidly instantia...

We have previously published a multiresolution approach for the shape similarity comparison of polygon soup 3D models. The approach combined a single-resolution shape feature with a multiresolution representation produced by using the 3D alpha shapes algorithm of Edelsbrunner for the shape similarity comparison. The study evaluated the efficacy of the multiresolution shape comparison approach b...

In this paper, we present an algorithm for the reconstruction of piecewise linear surfaces from unorganized sample points with improved a-shape. Alpha-shapes is based on eficient, discrete mathematics which determine exact relationships between points, shapes, and spaces. It generates a family of shapes according to the selected a parameter. The method discussed in this paper might be applied f...

Bounding hull, such as convex hull, concave hull, alpha shapes etc. has vast applications in different areas especially in computational geometry. Alpha shape and concave hull are generalizations of convex hull. Unlike the convex hull, they construct non-convex enclosure on a set of points. In this paper, we introduce another generalization of convex hull, named alpha-concave hull, and compare ...