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Improved Parameter Set for Adaptive Symbol Recognition

IP.com Disclosure Number: IPCOM000052662D
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 3 page(s) / 23K

Publishing Venue

IBM

Related People

Karnaugh, M: AUTHOR [+3]

Abstract

A set of model parameters is described for elastic matching of unknown symbols against a set of prototypes established by each individual writer in a symbol recognition system.

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Improved Parameter Set for Adaptive Symbol Recognition

A set of model parameters is described for elastic matching of unknown symbols against a set of prototypes established by each individual writer in a symbol recognition system.

Recognition systems are known for discrete handwritten symbols based upon elastic matching of the unknown symbols against a set of prototypes established by each individual writer. In such systems, the modeling of the symbols is derived from point data produced by the dynamic trace of a stylus on an electronic tablet. In one such system, the particular model parameters upon which the elastic matching operated were taken to be (1) the magnitude of the angle of the tangent at each point of the curve produced by the trace, and (2) the magnitude of the height of each point normalized to the given writing space guidelines. Both parameters are scaled to contribute the same "weight" in the metric used for the matching procedure.

The two-parameter system has difficulty in distinguishing certain pairs of symbols, for example, distinguishing between the two forms shown in the figure where the stroke ordering and direction are specified by the numbers and arrow heads, respectively. The angle and height measures alone are not sufficient to discriminate symbols whose component strokes differ by a horizontal translation.

Accordingly, in this article, two additional parameters are introduced, the x and y offsets from the center-of-gravity of the symbols. The x-offset incorporates information about the stroke's horizontal positions relative to one another. The y- offset enables the system to recognize symbols independent of their position relative to the baseline. This affords more flexibility to the writer in positioning the symbol when the exact vertical position is not important. The parameter for the normalized y-height from the baseline, on the other hand, enables the system to distinguish the vertical positions of the symbol, thereby allowing the discrimination of upper and lower case symbols which are made in an identical fashion, i.e., whose prototypes for upper and lower cases only differ in their relative vertic...