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Deep Follower Video Analysis

IP.com Disclosure Number: IPCOM000094850D
Original Publication Date: 1965-Jun-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 3 page(s) / 49K

Publishing Venue

IBM

Related People

Hurley, PJ: AUTHOR [+3]

Abstract

Some character recognition machines employing curve followers identify the unknown lexical symbol by analyzing the filtered deflection voltages that cause the cathode ray tube beam to follow the outline of the symbol. When the follower has a circular dither pattern whose diametrical dimensions are large with respect to the line thickness, the apparatus thus becomes capable of recognizing certain shape features by direct analysis of the video return.

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Deep Follower Video Analysis

Some character recognition machines employing curve followers identify the unknown lexical symbol by analyzing the filtered deflection voltages that cause the cathode ray tube beam to follow the outline of the symbol. When the follower has a circular dither pattern whose diametrical dimensions are large with respect to the line thickness, the apparatus thus becomes capable of recognizing certain shape features by direct analysis of the video return.

The trace diagrams, labelled I through IV, show some of the situations in which the circuit becomes active to distinguish the various shape features. In I, two examples of three hits, a hit being a transition from black to white, during a single revolution from T(0) to T(1) are shown. These hits, when counted in a counter alert the system to a departure from the following of a simple straight line in which only two hits per revolution are experienced. Both examples represent a succession of three equal length black intervals per revolution. In II, the T-joint can be further defined by examining the relative durations of the black intervals during two successive beam revolutions. Here, starting with T0, the return is a short black from A to B, a long black from C to D, a long black from E to F, and a short black from G to H. This gives rise to a short-long,long-short sequence.

In III, a line end is detected because no hit is encountered within the on time or late zones as measured by timing circuits which anticipate normal hit times for a straight line. This causes the follower to undergo a synthetic circle. This circle seeks to bridge small gaps in the line. If only one white to black transition is encountered before the synthetic circle, a signal is generated and presented to the logic as a line end.

In IV, the intersec...