Rotationally impervious feature extraction for optical character

Details Rotationally impervious feature extraction for optical character Rotationally impervious feature extraction for optical character

1990-05-07

1991-10-01

Moore, David K.

Image analysis

Histogram processing

For setting a threshold

382 23, 382 68, 382 25, G06K 946

Patent

active

050540947

ABSTRACT:
A feature-based optical character recognition system, employing a feature-based recognition device such as a neural network or an absolute distance measure device, extracts a set of features from segmented character images in a document, at least some of the extracted features being at least nearly impervious to rotation or skew of the document image, so as to enhance the reliability of the system. One rotationally invariant feature extracted by the system is the number of intercepts between boundary transitions in the image with at least a selected one of a plurality of radii centered at the centroid of the character in the image.

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