JPH0235355B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pattern recognition method employed, for example, in an optical character succession device.

Traditional pattern recognition methods can be roughly classified as follows:
There are methods such as pattern matching method, feature extraction method, sonde method, and combinations of these methods. In these systems, if misreadings are to be extremely reduced, it is necessary to make major changes to the pattern recognition unit itself to strictly define the permissible range of deformation of characters to be taken over. On the other hand, the use of a single dictionary requires a high rate of correct reading. Conventional pattern recognition methods have not been able to adequately meet such diverse demands.

The biggest cause of misreading is dust or dirt on the surface of the form on which the characters to be read are written, or the characters themselves are blurred. In that case, performing strong noise removal on the input pattern at the pre-processing stage of recognition is
It can even lead to mistakes. Furthermore, it is extremely difficult to design a recognition unit that takes into account the deformation of the input pattern due to the above-mentioned dust, etc.
It could not be said to be realistic in terms of development man-hours.

The present invention was made in view of the above circumstances, and
Utilizing a previously developed recognition circuit with a sufficiently high correct reading rate, it removes dust, dirt,
Prevents misreading of defective input patterns due to blurring, etc.
In addition, the requirement for a high correct reading rate can be met by directly deriving the output of a conventional recognition circuit, and it provides a pattern recognition method that can handle a wide variety of reading requests with a single dictionary. It is something to do.

An embodiment of the present invention will be described in detail below with reference to the drawings.

In the figure, 1 is a parameter recognition circuit.
This recognition circuit 1 has a function of recognizing an input pattern by referring to parameters stored in a dictionary section, and has a sufficiently high correct reading rate. If recognition is possible, this recognition circuit 1 outputs the recognition result character code (answer) as a recognition result, and also outputs various parameters related to the input data (for example, the number of character loops, similarity value, etc.)
Output. On the other hand, if recognition is not possible, a reject code is output as the recognition result. Reference numeral 2 denotes a switching circuit, for example, a firmware or hardware switch, which is provided to select whether to use the answer obtained by the recognition circuit 1 as the final recognition result or to further check the answer. It is being A first discrimination circuit 3 includes an input register 4 for storing output data (answers and parameters) of the recognition circuit 1 led through the switch 2, and parameters and parameters that should exist if the above answer is correct. A check memory table 5 stores in advance parameters that must not be met, as well as a mode for deciding how to proceed when conditions are not met, and this table 5 is referenced to determine the output of the register 4 as the final answer. The control circuit 6 has a control circuit 6 that makes a decision as to whether to perform a process, reject, or perform a more detailed check. Second discrimination circuit 7
In this case, answers and various parameters that require detailed checking are derived from the first discriminator circuit 3 (or recognition circuit 1), and an input pattern is derived. The second discrimination circuit 7 determines the above answer,
Analyze parameters and input patterns in detail,
It has a function to check the check points unique to the answer and determine whether the answer is valid or rejected. The first OR circuit 8 edits the reject code output from the recognition circuit 1 and each discrimination circuit 3, 7. The second OR circuit 9 edits the answer of the recognition circuit 1 selected by the switch 2 and the answers of the respective discrimination circuits 3 and 7.

Next, the operation of the above embodiment will be explained. The input pattern is processed by a recognition circuit 1, and this recognition circuit 1
, a reject signal indicating that the input pattern cannot be recognized, at least one or more recognition candidate result signals according to the recognition result, and the parameters obtained regarding the input pattern as described above.
output along with one or more recognition candidate result signals. If the recognition result from the recognition circuit 1 is to be obtained with even higher precision, the switch 2 is switched to the first discrimination circuit 3 side. This discrimination circuit 3
refers to the check memory table 5 predetermined for each answer for the answer and parameter input obtained by the recognition circuit 1, and checks whether there are necessary parameters or unnecessary parameters; Furthermore, it is determined whether the rejected characters should be rejected or sent to the second discrimination circuit 7 according to the mode determined in the table 5 above.
Therefore, the discrimination circuit 3 obtains a unique recognition result signal from the one or more recognition candidate result signals inputted using the contents of the check memory table 5 and the above-mentioned parameters, and also outputs a reject signal. This second determination circuit 7 analyzes the unique check points of the sent answer with emphasis and determines whether it should be output as an answer or rejected. The reject output of the recognition circuit 1, the reject output of the first discrimination circuit 3, and the reject output of the second discrimination circuit 7 are taken out from the first OR circuit 8. Further, the answer output of the first discrimination circuit 3, the answer output of the second discrimination circuit 7, and the answer output of the recognition circuit 1 when selected by the switch 2 are taken out from the second OR circuit 9.

According to the pattern recognition method described above, an additional function (answer check) can be added by selecting the discrimination circuit side with a switch without making major changes to the conventional recognition circuit that has already been developed and has a high correct reading rate. By adding this function, it is possible to drastically reduce misreading of characters within the standard without lowering the correct reading rate. Further, since the discrimination circuit mainly checks the checkpoints set according to the reading result of the recognition circuit rather than in the pre-processing stage of recognition, there is no risk of causing misreading to the recognition circuit. Further, a request for a high correct reading rate can be met by taking out the answer output of the recognition circuit as it is by using a switch. In addition, by changing the contents of the check table in the discrimination circuit, the ratio of misreading and reject rate can be changed to some extent, and one dictionary (provided in the recognition circuit) can meet various reading rate requirements. can be dealt with.

As described above, the present invention utilizes a recognition circuit that has been developed in the past and has a sufficiently high correct reading rate, and further checks the response output of this recognition circuit without reducing the correct reading rate. Prevent misreading of defective input data due to dust, dirt, blurring, etc. for characters within the standard, and meet the requirement for a high correct reading rate by directly deriving the output of the conventional recognition device. It is possible to provide a pattern recognition method that can handle a wide variety of reading requests with a single dictionary.

Although the above embodiment describes the recognition process of input data corresponding to a character pattern, the recognition process is not limited to this, and input data corresponding to a voice pattern, a three-dimensional figure pattern, etc. can also be recognized in accordance with the above embodiment. .

[Brief explanation of drawings]

The drawing is a diagram showing an embodiment of the pattern recognition method according to the present invention. DESCRIPTION OF SYMBOLS 1...Pattern recognition circuit, 2...Switching circuit (switch), 3...First discrimination circuit, 7...Second discrimination circuit.

Claims (1)

[Claims] 1 recognizes an input pattern, and a reject signal indicating that the input pattern cannot be recognized;
a pattern recognition means for outputting at least one or more recognition candidate result signals according to the recognition result, and a parameter obtained with respect to the input pattern attached to the one or more recognition candidate result signals; A pattern recognition method comprising a switching means for selecting whether or not to output the recognition result of the output of the pattern recognition means as an answer as it is, and a determination means for outputting the only recognition result including a check memory table and a reject signal. When attempting to obtain recognition results from the pattern recognition means with higher precision, the one or more recognition candidate result signals and the recognition results obtained regarding the input pattern are switched via the switching means. and the parameters are sent to the determining means, and the determining means obtains a unique recognition result signal from the one or more recognition candidate result signals inputted using the contents of the check memory table and the parameters. A pattern recognition method characterized by outputting a reject signal when determination is impossible.