Method for identifying a sequence of alphanumeric characters
First Claim
1. A method of identifying a sequence of alphanumeric characters, comprising the steps of:
- (a) producing a grey level image of said character sequence,(b) locating potential characters from said grey level image including filtering said image with a long horizontal and long vertical line segments removal filter,(c) normalizing the size and contrast of said extracted potential characters as grey level character images, and(d) inputting said normalized potential characters as grey level character images to a character recognition means, wherein said character recognition means comprises two network classifiers, a first one of said network classifiers comprising a first hidden layer feed forward neural network which classifies the input pattern into a first set of categories, and the second one of said network classifiers comprising a second hidden layer feed forward neural network which recognizes the pattern from the first set of pattern categories.
3 Assignments
0 Petitions
Accused Products
Abstract
A character recognition system is described, in particular a system suitable for use in monitoring cargo container codes or vehicle number plates. An image of the code is first analyzed to extract potential characters. As part of this process, long horizontal and vertical line segments are filtered out. The extracted potential characters are then input to a two-level character recognition means. The first level comprises a neural network classifier that classifies a character into a smaller set of possible characters; and then the second level comprises another neural network classifier which identifies which character among the smaller set of possible characters the extracted character is.
-
Citations
10 Claims
-
1. A method of identifying a sequence of alphanumeric characters, comprising the steps of:
-
(a) producing a grey level image of said character sequence, (b) locating potential characters from said grey level image including filtering said image with a long horizontal and long vertical line segments removal filter, (c) normalizing the size and contrast of said extracted potential characters as grey level character images, and (d) inputting said normalized potential characters as grey level character images to a character recognition means, wherein said character recognition means comprises two network classifiers, a first one of said network classifiers comprising a first hidden layer feed forward neural network which classifies the input pattern into a first set of categories, and the second one of said network classifiers comprising a second hidden layer feed forward neural network which recognizes the pattern from the first set of pattern categories. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification