Patent ID: 6178262
Filing Date: 2001-01-23
Classification: G06K,H05K

Abstract:
An apparatus for locating a curvilinear symbol comprising:a. means for generating a grey scale model of a segment of an idealized curvilinear symbol by interpolating curvature at the periphery by assigning foreground pixel values to those pixels located entirely within said grey scale model of said segment of said idealized curvilinear symbol, assigning background pixel values to those pixels located entirely outside said grey scale model of said segment of said idealized curvilinear symbol, and approximately pixel values for boundary pixels of said grey scale model of said segment of said idealized curvilinear symbol by selecting a number of points n, along an arc of said idealized curvilinear symbol that is smaller than the total number of points in said arc, connecting said points n, by straight lines to create an angular feature in each pixel boundary, computing the area of each such angular feature, and computing a grey scale level for each boundary pixel by scaling the grey value by the percentage of said pixel occupied by said angular feature;b. means for generating a full size model by reflecting said grey scale model of said segment of an idealized curvilinear symbol around the axes of symmetry of said idealized curvilinear symbol;c. means for searching a digitized image for the location of shapes corresponding to said full size model; andd. means for generating subfeature models from said full size model.