JPS5856907B2 - Identification method using differential mask - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an identification method using a differential mask, particularly a differential mask pattern that extracts differences between similar characters, and an identification method using a differential mask that emphasizes the differences for judgment. In the identification method, the storage capacity required for the differential mask memory for storing the differential mask pattern is significantly reduced, and furthermore, while scanning the human cover pattern, the G is compared with the differential mask pattern. This relates to an identification method based on a differential mask O.

For example, in the recognition of printed characters, so-called patterns and
A matching method is adopted to correlate the input cover pattern with each standard pattern and perform identification.

However, when distinguishing between similar characters, sufficient differences do not appear in the correlation values.

For this reason, we prepare a differential mask pattern that extracts only the differences between similar characters, and then correlate the input cover pattern with the standard pattern, and compare the input cover pattern with the above differential mask pattern to obtain details. A method of checking is adopted.

Such a method is particularly effective when the figure to be recognized is a kanji character, but in kanji recognition (for example, a figure frame of 64 x 64 bits, that is, 4 bits is used as a figure frame, and the above-mentioned differential mask pattern If you try to store it properly, you will need a total of 8 bit/character differential mask memories.

This is because it is necessary to separately store black point information indicating that the point should be a black mesh point and white point information indicating that the point should be a white mesh point as a differential mask pattern.

The present invention aims to solve the above points,
The aim is to store only essential information in the differential mask memory, noting that the information that should be stored as a differential mask pattern is only the differences between similar characters. .

Therefore, the identification method using a differential mask of the present invention not only correlates the input pattern with the standard pattern, but also prepares a differential mask pattern that extracts only the differences between similar characters, and uses the above-mentioned correlation result as the identification result. In the identification method using a differential mask, which is checked based on the comparison result between the differential mask pattern and the filled-in cover pattern,
The black point information corresponding to the representative point belonging to the black mesh point G in the differential mask pattern, the white point information corresponding to the representative point belonging to the white mesh point, and the information of the husband are located on the differential mask pattern. In addition to creating a differential mask memo IJK for storing the black point information and coordinate information, the differential mask memory is configured to have a predetermined number of address positions corresponding to each character to be recognized. Enable information indicating that the pair is a valid information pair is set at the address position where the pair and the pair of the white point information and the coordinate information are stored, and the human cover turn in which the above human cover turn is stored.・A comparison means for comparing the address for reading out the contents of the memory and the coordinate information stored in the memory, and when the comparison means issues a matching output, the above-mentioned person cover turn.・Comprising means for comparing the read data from the memory with the value of the white point information or the black point information on the differential mask memory, and provides instructions based on the coordinate information O stored on the differential mask. This feature is characterized in that the above-mentioned cover pattern is compared with the differential mask pattern at the position where the pattern is displayed.

This will be explained below with reference to the drawings.

FIGS. 1A, B, and C are examples of similar character patterns according to the present invention; FIGS. 2A, B, and C are difference patterns obtained by extracting differences between similar characters; and FIG. 3A.

B and C are differential masks created corresponding to each similar character.
An example of a pattern, FIGS. 4A, B, and C is an example differential mask pattern to be stored on a differential mask memory;
FIG. 5 shows an embodiment of the differential mask memory, and FIG. 6 shows the configuration of an embodiment of the present invention.

First, the differential mask pattern referred to in the present invention will be conceptually explained with reference to FIGS. 1 to 4.

For example, when distinguishing between the characters ``工'', ``王'', and ``tama'', the character ``工'' is shown in Figure 1A (here, the character ``王'' is shown in Figure 1A).
In Figure B, the character "tama" is given as a standard pattern as shown in Figure 1C.

Note that the code 1 in the figure is a figure frame, 2-0, 2-1, 2-
2 each represent a standard pattern.

The input cover pattern to be identified, for example, the input cover pattern corresponding to the character "King" is selected from each standard pattern 2-0゜2-1,2-
When comparing correlation with standard pattern 2-1, the correlation value is originally the maximum for standard pattern 2-1, and standard pattern 2-0.
There should be a sufficient difference compared to the correlation values for 2-2 and 2-2.

However, in general, human cover turns have slight deformations, and it is not always possible to judge between the characters ``tech'', ``king'', and ``tama''.

A differential mask pattern is prepared for this purpose.

That is, by comparing the standard patterns 2-0 and 2-1, a difference pattern as shown in FIG. 2A can be obtained.

Further, by comparing the standard patterns 2-1 and 2-2, a difference pattern as shown in FIG. 2B can be obtained.

Furthermore, by comparing the standard patterns 2-2 and 2-0, a difference pattern as shown in FIG. 2C is obtained.

In the figure, 1 represents a graphic frame, and 3-B to 3-2 represent different pattern patterns, respectively.

Using the characters ``person'' or ``C'' in Figure 2, the characters ``technical'', ``king'', and ``
3 is prepared as a differential mask pattern for identifying the difference between the ball and the ball.

That is, the pattern shown in Figure 3 as a differential master pattern corresponding to the character ``K'' is the character ``King'' (the pattern shown in Figure 3B as the corresponding differential mask pattern is the character ``Tama''). The patterns shown in FIG. 3C are prepared as differential mask patterns corresponding to the respective patterns.

In the figure, 1 represents a figure frame, 4-B to 4-2 represent differential mask patterns, and hatched areas 4-11, 4-
21 represents a pattern portion that should be a black mesh point, dotted portions 4-00° and 4-10 represent a pattern portion that should be a white mesh point.

When the human cover turn is correlated with the standard pattern 2-0 of the human figure in FIG. 1, the incoming cover turn is also compared with the differential mask pattern of the human figure in FIG.

Then, it is checked whether the human cover turn correctly corresponds to the own mesh point in the point portion 4-00 shown in FIG. 3.

Needless to say, when the human cover turn is compared with the differential mask pattern shown in FIG. Check to see if the white mesh point is correct (rubbing).

However, in reality, considering the deformation of the input cover pattern, the third
In place of the differential mask patterns 4-b to 4-2 shown in FIGS.

In the figure, numeral 1 is a graphic frame, and 5-0 and 5-1 are differential mask patterns, respectively, and 5-OO.

5-10 are white point information parts that should be white mesh points, respectively;
5-11 and 5-21 respectively represent black point information portions that should be black mesh points.

Difference mask patterns such as those shown in Figures 4 to 4 are prepared for each character object, but in order to store such a difference mask pattern in a storage device, a storage capacity corresponding to the coordinate position of graphic frame 1 is required. It is not recommended to prepare.

That is, it is not preferable to prepare a differential mask memory with a storage capacity of 64×64 (bits)×2.

This is because, considering the number of examples, the positions of information 5-0 to 5-2 are extremely small in terms of the overall size of the graphic frame 1.

In consideration of the above points, in the case of the present invention, for example, a maximum of 16 bits
A differential mask memory for 32 (words), that is, 512 bits is prepared, and the differential mask pattern is stored in the memory.

FIG. 5 shows one embodiment of the differential mask memory used in the present invention.

Reference numeral 6 in the figure is a differential mask memory, 17-ro to 1
γ-31 represents an address position, 18 represents an enable bit, 19 represents black and white point information, and 20 represents address information on the differential mask pattern.

That is, in the differential mask pattern G as shown in Fig. 4, the coordinates AO position (there is a black mesh point, the coordinates A1
There is a black mesh point at the coordinate A2 position, a white mesh point is at the coordinate A2 position, etc. There is a black mesh point at the coordinate A (n-1) position, and a white mesh point is at the coordinate A (n) position. Assuming that there is a mesh point, address position 17 of memory 6
-00 Enable bit of logic “1” and logic “1”
Similarly, an enable bit of logic "1" and a logic "1" are stored at address position 1γ-1.
” and the coordinates A1 are stored, and the address position 1T is stored.
-2 stores the enable bit of logic "1", white point information of logic "0", and coordinate A2; ”, the enable bit of logic “1”, black point information of logic “1”, and coordinates A(n-1) are stored, and the enable bit of logic “1”, black point information of logic “0”, and coordinates are stored in address position 17-n. A(n) and address locations 17-(n+1) to 1T-
31c is set to store the enable bit logic '0'.

Therefore, assuming that one word is 16 bits, the differential mask memory corresponding to each character is 16 bits x 32 (words), or 51 bits.
2 bits will be sufficient.

In addition, when storing the above coordinates A1 to A(n), address positions 17-
0 to 17-n (described later (6th
The comparison process shown in Figure) should be carried out efficiently.

FIG. 6 shows the configuration of an embodiment of the present invention, in which reference numeral 6 is a differential mask memory, 21 is an input cover turn memory, and the human cover pattern is aligned with the figure frame 11 shown in FIG. What is set above, 32 is the memory address counter, 33 is the differential mask memory address.
Counter, 34 is a comparison circuit, 35 is an exclusive OR circuit, 3
6 represents an AND path.

The human cover turn memory 21 (in this case, the input cover pattern as a result of scanning an input figure (not shown) is, for example, from the upper left corner of the figure frame 1 to the coordinates 0, 0 of the white point mesh, and the position i0.1.
is a white point mesh, ......, coordinates i, j are black point mesh, ..., coordinates 63.63 is a white point mesh, then logic "0" is set at address position "00". , Logic "0" at address position "0, 1", Logic "l" at address position "i, j", Logic "O" at address position "63, 63j" is stored.

In comparing the human cover turn and the differential mask pattern, counters 32 and 33 are each reset to "0".

From this state, the counter 32 is sequentially incremented.

When the contents of the counter 32 represent "0,0", white point information (logical "O") corresponding to the coordinates 0,0 of the human cover pattern is read out from the memory 21.

Thereafter, as the contents of the counter 32 are incremented as ro+ij..., the white point information corresponding to the input pattern coordinates 0, 1, etc. from the memory 21...
is read out.

The read human cover pattern information is used for correlation processing with the standard pattern.

Meanwhile, from the differential mask memory 6, the address position 1
The contents of 7-0 are output, and the coordinate information AO in the contents is manually input to the comparison circuit 34.

The enable bit 18 is also supplied to an AND circuit 36, and the black and white information 19 is supplied to an exclusive OR circuit 35.

As the counter 32 increments, when the output of the counter 32 reaches a value that matches the coordinate information AOG, the comparison circuit 34 issues a match output.

At this time, from the memory 21, information corresponding to the black or white point mesh point of the human cover at the coordinate position AOG is stored.
1” or “O” is output.

If the information on the coordinate position AO of the input pattern is a logic "1", the exclusive OR circuit 35 outputs a logic "0".

Therefore, AND circuit 36 is not turned on.

Then, the coincidence output O of the comparator circuit 34 causes the counter 33
is incremented by 1, and the coordinate information A1 is output from the differential mask memory 6.

Thereafter, the contents of the counter 32 are incremented.

However, the coordinates AI, A2... in this large cover turn
..., A(nM) When the information corresponding to the corresponding black or white mesh point does not match the information 19 read from the differential mask memory 6, and the enable bit 18 is logic "1". At some point, AND circuit 36 is turned on and generates a pattern mismatch signal.

Then, a process is performed to correlate the large cover turn with the standard pattern, but the pattern mismatch signal indicates that the incoming cover turn does not correspond to the standard pattern.

As explained above, according to the present invention, the differential mask memory 6 for storing differential mask patterns only needs to be 16 bits x 32 (words), or 512 bits per character.

Further, while scanning the cover pattern using the counter 32, it is possible to perform comparison with the differential mask pattern.

[Brief explanation of the drawing]

FIGS. 1A, B, and C are examples of similar character patterns according to the present invention; FIGS. 2A, B, and C are difference patterns obtained by extracting differences between similar characters; and FIG. 3A. B and C are differential masks created corresponding to each similar character.
An example of a pattern, FIGS. 4A, B, and C is an example of a differential mask pattern to be stored on a differential mask memory. FIG. 5 is an example of an embodiment of a differential mask memory, and FIG. The structure of an embodiment of the present invention is shown in detail. In the figure, 1 is a graphic frame, 2 is a standard pattern, 5 is a differential mask pattern, 6 is a differential mask memory, 18 is enable information, 19 is black and white point information, 20 11-b to 17-31 are coordinate information, 21 is a cover turn memory, 32 and 33 are address counters, 34 is a comparison circuit, 35 is an exclusive OR circuit, and 36 is an AND circuit.

Claims (1)

[Claims] 1. A differential mask pattern is prepared by correlating a person's cover turn with a standard pattern and extracting only the difference between similar characters, and the identification result based on the correlation result is applied to the differential mask pattern. In the identification method using a differential mask, which is checked based on the comparison result between the above-mentioned human cover pattern and the above-mentioned human cover pattern, the above-mentioned differential mask pattern (black point information corresponding to the representative point belonging to the black mesh point in the field, and corresponding to the representative point belonging to the white mesh point in the A differential mask memory is provided for storing white point information and coordinate information where each piece of information is located on the differential mask pattern, and the differential mask memory is predetermined corresponding to each character to be recognized. an enabler for instructing that the pair of black dot information and coordinate information and the pair of white dot information and coordinate information are valid information pairs; The information is set up, and the input cover turn memo J in which the above-mentioned input cover turn is stored, the address for reading the contents of the input cover turn memory, and the coordinate information stored in the above-mentioned difference mask memory Q. Comparing means for comparing, and collating means for collating the read data from the human cover pattern memory and the value of the white dot information or the black dot information on the differential mask memory when the comparing means issues a matching output. A differential mask identification method, characterized in that the human cover pattern and the differential mask pattern are compared on the differential mask (at a position indicated by the stored coordinate information). 2 The information stored as valid information pairs on the differential mask memory is stored in address positions of the differential mask memory in order according to the order of values given by the coordinate information, and the differential mask - The identification method using a differential mask according to claim 1, wherein the memory is accessed in the order of the address positions while scanning the cover pattern, and the corresponding storage contents are read out. .