Patent Document ID: 5394482
Application ID: 08177294
Patent Status: 1

Claim One:
1. A method of detecting the presence of dot-matrix printed text from other types of printed text in an image by processing bi-level pixel video data of text characters, comprising the steps of: locating a kernel of M rows by N columns of pixels to a location in said image; moving said kernel to the next adjacent pixel position and examining the image data contained in the kernel and labeling those pixel positions with a flag when the bit pattern at the current location matches one or more of the following bit patterns: (a) where there are one or more adjoining black pixels in a column forming a group of three vertical groups of black pixels in the same column are separated from adjacent groups by at least one white pixel in the column; (b) where there are one or more adjoining black pixels in a row forming a group and three horizontal groups of black pixels in the same row are separated from adjacent groups by at least one white pixel in the row; (c) where there are one or more adjoining black pixels in a given left-diagonal forming a group and three groups of black pixels along said given left-diagonal are separated from adjacent groups by at least one white pixel along the same left diagonal; (d) where there are one or more adjoining black pixels in a given right-diagonal forming a group and three groups of black pixels along said given right-diagonal are separated from adjacent groups by at least one white pixel along the same right-diagonal; and when any of the above patterns are found, creating and outputting a filter mask of M rows by N columns that is indicative of the location of dot matrix text in the image.