A new kind of quasi-quartic trigonometric polynomial base functions with a shape parameter λ over the space Ω=span {1, sint, cost, sint2t, cos2t} is presented, and the corresponding quasi-quartic trigonometric Bézier curves and surfaces are defined by the introduced base functions. The quasi-quartic trigonometric Bézier curves inherit most of properties similar to those of quartic Bézier curves...

Analogous to the cubic Bézier curve, a quartic trigonometric Bézier curve with a shape parameter is presented in this paper. Each curve segment is generated by four consecutive control points. The shape of the curve can be adjusted by altering the values of shape parameters while the control polygon is kept unchanged. These curves are closer to the control polygon than the cubic Bézier curves, ...

A class of cubic Bézier-type curves based on the blending of algebraic and trigonometric polynomials, briefly CAT Bézier curves, is presented in this paper. The CAT Bézier curves retain the main superiority of cubic Bézier curves. The CAT Bézier curves can approximate the Bézier curves from the both sides, and the shapes of the curves can be adjusted totally or locally. With the shape parameter...

This paper presents a novel method for the multi-scale seg-mentation and shape characterization of unsharp, blobby structures in gray-valued image data. The iso-level curves of unsharp blobs depict a set of concentric curves, representing the shape by the geometric properties of the level curves and by the radial intensity function. Applying Euclidean shortening ow progressively smoothes the le...

The shape of steady-state current-distance (i,-d) curves obtained by scanning electrochemical microscopy (SECM) with a submicrometer conical-type tip is substantially different from that obtained with a microdisk tip. A model is proposed to describe the i,-d curves for tips shaped as cones or spherical segments. In each case a family of theoretical working curves, computed for different values ...

The present study reports the changes in configuration of maximal flow-volume curves after eight weeks' treatment with inhaled corticosteroids in 14 asthmatic patients. The configuration was compared with that seen after bronchodilatation following inhalation of a single dose of ipratropium bromide. After inhaled corticosteroids the shape of the flow-volume curves was less bowed toward the volu...

This paper presents a novel approach – WireWarping for computing a flattened planar piece with length-preserved feature curves from a 3D piecewise linear surface patch. The property of lengthpreservation on feature curves is very important to industrial applications for controlling the shape and dimension of products fabricated from planar pieces. WireWarping simulates warping a given 3D surfac...

An algebraic curve is deened as the zero set of a polynomial in two variables. Algebraic curves are practical for modeling shapes much more complicated than conics or superquadrics. The main drawback in representing shapes by algebraic curves has been the lack of repeatability in tting algebraic curves to data. A regu-larized fast linear tting method based on ridge regression and restricting th...