Patent Document ID: 5563955
Application ID: 07616624
Patent Status: 1

Claim One:
1. An apparatus for recognizing POSNET bar codes comprising: (a) an imaging assembly operative to scan a piece of mail and to generate digital vertical scan line pixel data relating thereto; (b) a memory operative to store said digital vertical scan line pixel data in a matrix and to allow said pixel data to be read therefrom either as horizontal or vertical scan lines; (c) a direct memory access controller coupled to said memory and operative to directly access said memory and read portions thereof and selectively transmit either vertical scan lines of pixel data or horizontal scan lines of pixel data; (d) a digital matched filter operative to receive horizontal scan lines of said pixel data from said memory under the control of said direct memory access controller, said digital matched filter having coefficients selected to high cross-correlate with pitches of said POSNET bar codes, said digital matched filter having an output; (e) a post filter processor operative to receive said output from said digital matched filter to identify high cross-correlations between said digital matched filter coefficients and a horizontal scan line of pixel data and to generate start and stop signals indicative of a beginning and ending of at least one area of pixel data in said memory having a high cross-correlation with said filter coefficients; (f) a device operative to receive said start and stop signals and to generate memory addresses defining a perimeter within said memory and about said pixel data in an area of said memory with respect to which a high cross correlation was detected; and (g) a recognition circuit operative to receive vertical scan lines of pixel data from said area of high cross correlation from said memory under the control of said direct memory access controller and to perform gray scale to binary image conversion on said pixel data within said area and to decipher any bars of a bar code therein.