Handwritten Fonts Modeling Based on Fat Lines of Variable Width

Abstract

In this paper we consider a new geometrical primitive - a curve of variable width (a fat curve). The fat curve is a trace of circle with variable radius moving along a smooth trajectory of the finite length called as an axis. For the mathematical description of such primitives cubic B-splines are used. By means of them it is possible to specify both an axis and a radius value (a thickness) of a fat curve. We solve a problem of representation of hand-written characters given as raster binary images in the form of association of fat curves. We demonstrate a possibility of modeling of "real" handwriting by entering small deformations into the form of fat curves. We consider a method of automatic kerning (visual alignment of letter spacing) of hand-written characters given as curves of variable width. We describe the way of output of arbitrary text presented by series of fat curves on raster-scan devices (printed output, displayed output). A prototype of a font editor of fat curves was developed by the authors of this paper. The presented approach can be used as embedded module (plug-in) in font editors of hand-written characters.