Pattern identifying systems

• US 3,869,697 A
• Filed: 01/10/1973
• Issued: 03/04/1975
• Est. Priority Date: 01/13/1972
• Status: Expired due to Term

• Current Assignee: Harumi Kawasaki
• Original Assignee: Harumi Kawasaki
• Inventors: Kawasaki, Harumi
• Primary Examiner(s): Shaw, Gareth D.
• Assistant Examiner(s): Boudreau, Leo H.
• Application Number:
  US05/322,553
• Time in Patent Office: 783 Days
• Field of Search: 340/146.3F,146.3P,146.3Q,146.3H 356/71 350/3.5,162SF 250/204
• US Class Current: 382/206
• CPC Class Codes: G06V 10/88 Image or video recognition using optical means, e.g. reference filters, holographic masks, frequency domain filters or spatial domain filters
• CPC Class Codes: G06V 30/10 Character recognition
• CPC Class Codes: G06V 30/18 Extraction of features or characteristics of the image
• CPC Class Codes: G06V 30/186 by deriving mathematical or geometrical properties from the whole image

Abstract

A system for identifying two-dimensional patterns. According to this system, a pattern which is to be identified is positioned at a reading location and a Fourier transformation image of the pattern is provided by an optical structure which is distributed along a predetermined optical axis. The Fourier transformation image is picked up by a photosensitive assembly which detects angular and radial components of the Fourier transformation image. These components are electrically converted into corresponding linear distributions which are then quantized. The detection of the angular and radical components of the Fourier transformation image takes place simultaneously throughout all parts of the image.

Claims

1. In a system for identifying two-dimensional patterns, positioning means for positioning a pattern which is to be identified at a reading location, optical means for forming a Fourier transformation image of a pattern at said reading location, said optical means having an optical axis extending through said reading location and having elements distributed along said optical axis before and behind said reading location, photosensitive means positioned with respect to said optical axis for receiving said Fourier transformation image and for detecting angular and radial components thereof, electrical converting means electrically connected with said photosensitive means for receiving an input therefrom formed by said components and for converting said components respectively into corresponding binary representations which form an output of said electrical converting means, and correlating means electrically connected to said electrical converting means for receiving said binary output therefrom and for electronically correlating said output with reference binary representations to achieve therefrom a signal which identifies the pattern at said reading lOcation, a differentiating means being optically connected with said optical means for differentiating between two parts of the pattern at said reading location prior to its formation into a Fourier transformation image, and electrical transmitting means electrically connected between said differentiating means and said correlating means for comparing the two parts and transmitting to the differentiating means an additional signal according to the difference between the light passing through two parts of the pattern at said reading location for providing at said correlating means an increased capacity for discriminating between different patterns.

2. In a system for identifying two-dimensional patterns, positioning means for positioning a pattern which is to be identified at a reading location, optical means for forming a Fourier transformation image of a pattern at said reading location, said optical means having an optical axis extending through said reading location and having elements distributed along said optical axis before and behind said reading location, photosensensitive means positioned with respect to said optical axis for receiving said Fourier transformation image and for detecting angular and radial components thereof, electrical converting means electrically connected with said photosensitive means for receiving an input therefrom formed by said components and for converting said components respectively into corresponding linear distributions which form an output of said electrical converting means, and quantizing means electrically connected to said electrical converting means for receiving said output therefrom and for quantizing said output to achieve therefrom a signal which identifies the pattern at said reading location, said optical means including an image-transmitting means for transmitting the Fourier transformation image along a pair of distinct paths, said photosensitive means including an angular photosensitive unit situated along one of said paths for detecting angular components of the image transmitted along said one path and a radial photosensitive unit situated along the other of said paths for detecting radial components of the image transmitted along said other path, said angular photosensitive unit including a series of angularly arranged optical fibers for responding to the presence or absence of an image at the location of said fibers and a plurality of photocells respectively connected with said fibers for providing an array of signals according to the response of said fibers, said radial photosensitive unit including a plurality of concentric optical fiber rings for responding to the presence or absence of radial components of the Fourier transformation image and a plurality of photocells connected with said rings for providing an array of signals according to the response of said rings, said electrical converting means including an angular register unit electrically connected with said photocells of said angular photosensitive unit and having a number of places equal to the number of the latter photocells, said register places and said photocells all operating simultaneously and in parallel and further including a radial register unit electrically connected with said optical fiber rings and having a number of places equal to the number of rings for memorizing signals therefrom, said places of said radial register unit operating simultaneously and in parallel with said optical fiber rings and said angular and radial photosensitive units operating simultaneously so that evaluation of the entire Fourier transformation image takes place at all parts at the same time, said angular and radial register units both being electrically connected with said quantizing means for simultaneously transmitting signals thereto, and wherein a differentiating means is optically connected with said optical means for differentiating between predetermined parts of a pattern at said reading location, and signal-transmitting means elecTrically connected between said differentiating means and said quantizing means for transmitting to the latter an additional signal according to the difference between the parts of a pattern as detected by said differentiating means, said signal-transmitting means including a third register for receiving a signal from said differentiating means according to the difference, if any, between the parts of the pattern differentiated by said differentiating means, and said third register being electrically connected with said quantizing means for transmitting an additional signal to the latter which increases the discriminating capacity of said quantizing means.