JPH0580707B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for creating a character dictionary for character recognition.

[Background of the invention]

As one method for creating a character dictionary for character recognition, the inventor extracted the strokes of characters to be registered in the character dictionary (master characters) and displayed them on the screen of a display device, and an operator observed the strokes. We have been researching a method in which a stroke code corresponding to that stroke is input, and that stroke code is registered in a character dictionary together with information on the stroke position and size of the master character.This method is quite efficient. It has been confirmed that it is possible to create a character dictionary, but on the other hand, there are cases where inappropriate stroke codes are registered due to errors in operator judgment, and the problem is that it takes a considerable amount of time to correct the errors. It turned out that there is.

〔the purpose〕

An object of the present invention is to provide an efficient character dictionary creation method that solves the above-mentioned problems.

〔composition〕

The character dictionary creation method according to the present invention includes means for extracting strokes, their positions and sizes from a master character pattern, means for displaying the extracted strokes, and storing stroke information for synthesizing standardized strokes. means for an operator to enter a stroke code;
Means for synthesizing a stroke corresponding to a stroke code input by an operator and a pattern of strokes belonging to the same classification based on stroke information and information on stroke size and position extracted from a master character; The present invention is characterized by comprising means for performing matching with a stroke pattern extracted from a master character and registering a stroke code of a synthetic stroke with the highest degree of matching in a character dictionary.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

〔Example〕

FIG. 1 is a block diagram showing one embodiment of the present invention. In this figure, 10 is a storage device that stores a master character pattern, 12 is a stroke extraction device that extracts strokes, their positions and sizes from the master character pattern, and 14 is a storage device that stores a stroke table. 16
18 is a storage device that stores stroke information for composing strokes, and 18 is a stroke synthesis device that synthesizes stroke patterns based on the stroke information and the position and size of the stroke (master stroke) extracted by the stroke extraction unit 12. , 20 is an input device for an operator to input a stroke code, 22 is a storage device for storing a character dictionary, 24 is a display device, and 26 is an arithmetic and control device that performs processing such as controlling and matching each of the above parts. . Each part is connected via a system bus 28.

In this example, the third stroke is
We are considering 42 types shown in the figure. The number (16) above each stroke (shown as a core wire) in this diagram
decimal representation) is its stroke code. Further, in this embodiment, 42 types of strokes are divided into 13 categories based on the bending direction and thick line information (described later). A stroke table classified in this manner is shown in FIG. This stroke table is stored in the storage device 14.

Stroke information stored in the storage device 16 is conceptually shown in FIG. Each stroke information consists of a stroke code, a proportion indicating the length of the stroke, thickening information for fleshing out the stroke, and a chain code for developing the stroke into a bit pattern.

This chain code expresses the direction of transition from one dot to the next on a core line as a series of direction vector codes 0 to 7 and stop code 0, as shown in Figure 7, when a stroke is developed into bits. This is what I did.

The thick line information is as shown in the conceptual diagram in Figure 8.
It consists of a feature code, node coordinates, and thickness data (L, R). The feature code is a code that defines the part of the stroke to be fleshed out. As exemplified in FIG. 9 (this figure shows a stroke such as the part that falls on the lower left of "Large"), the node coordinates indicate the X-direction coordinates of the point at which the thickness of the stroke changes.
The thickness data indicates the width to be added to the center line of the stroke from left to right in the Y direction.

FIG. 2 is a flowchart of the character dictionary creation process in this embodiment. Each processing stage will be explained in turn with reference to this figure.

The master character pattern of the characters to be registered in the character dictionary is stored in the storage device 1 by the arithmetic and control unit 26.
0 and input to the stroke extraction device 12 (step 30).

The stroke extraction device 12 extracts the core lines of the master character pattern (step 32), and then extracts the strokes (step 34). The extracted master stroke pattern and its position and size data are stored in the memory within the arithmetic and control unit 26, and are transferred to and displayed on the display device 24 under the control of the arithmetic and control unit 26 (step 36). .

The operator observes the master stroke pattern displayed on the display device 24 and inputs a stroke code that seems to correspond to the master stroke from the input device 20 (step 38).

The arithmetic and control unit 26 searches the stroke table 14 using the stroke code input by the operator, and finds all stroke codes (candidate stroke codes) belonging to the same classification as the stroke code (step 40). for example,
When stroke code 0120 is input, 0120 and 0390 are obtained as candidate stroke codes.

Next, the arithmetic and control device 26 provides each candidate stroke code and data on the position and size of the master stroke (currently displayed) to the stroke synthesis device,
Start the device. The stroke synthesizer 18 is
Stroke information corresponding to each candidate stroke code is read from the storage device 16 and strokes are synthesized according to the stroke information. At this time, the synthesized stroke is scaled (step 41).
The resulting composite stroke is sent to the arithmetic and control unit 26 and temporarily stored in its internal memory.

The arithmetic and control unit 26 matches the composite stroke pattern of each candidate stroke code with the master stroke pattern (before core formation), and calculates the matching rate M=(A+C)/(B+C) (step 42). ). Here, A to C are the numbers of pixels in the areas with the same symbols shown in FIG. In this figure, solid line 50 is the master stroke pattern and dashed line 52 is the composite stroke pattern. That is, the ratio between the number of mismatched pixels and the number of matching pixels between strokes is calculated as the matching rate.

Next, the arithmetic and control unit 26 selects the composite stroke with the highest matching rate (minimum matching rate) with the master stroke from among the composite strokes, and determines whether the matching rate is greater than or equal to a specified value (step 1).
44). If the matching rate is greater than or equal to the specified value, the arithmetic and control unit 26 registers the stroke code of the composite stroke in the master character entry of the character dictionary 22 along with the master stroke position and size information (step 46). ), proceed to process the next stroke.

If the highest matching rate is less than the specified value, the arithmetic and control unit 26 cancels the candidate stroke code and causes the display unit 24 to display a message prompting the input of another stroke code for the currently displayed master stroke (step 48). ),
Waits for input from the operator.

Through the above processing, the stroke code for each stroke of the master character and information on the position and size of the stroke are registered in the character dictionary, thereby creating a character dictionary for the master character. A similar process is performed for all necessary master characters to create a character dictionary for character recognition.

Note that the stroke extraction, stroke synthesis, and magnification processing described above are already known, so the details thereof will not be explained.

〔effect〕

As explained above, according to the present invention, not only the composite stroke corresponding to the stroke code input by the operator, but also the composite stroke of other stroke codes belonging to the same classification as that stroke code, can be combined with the master stroke. Matching is performed, the composite stroke with the highest matching rate is selected, and that stroke code is registered in the character dictionary. This eliminates the possibility of inappropriate stroke codes being registered in the character dictionary due to an operator's judgment error, making it easier to create a character dictionary. It can greatly improve efficiency.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Figure 2 is a flowchart showing the processing flow of the same embodiment, Figure 3 is a diagram showing strokes and their codes symmetrically, Figure 4 is an explanatory diagram of a stroke table, and Figure 5 is a master stroke and composite stroke. Fig. 6 is a conceptual diagram of stroke information, Fig. 7 is a diagram showing the direction vector code used in the chain code, Fig. 8 is a conceptual diagram of thick line information, and Fig. 9 is a conceptual diagram of thick line information. FIG. 3 is an explanatory diagram of conversion information. 10... Master character pattern storage device, 1
2... Stroke extraction device, 14... Stroke table storage device, 16... Stroke information storage device, 18... Stroke synthesis device, 20...
...Input device, 22...Character dictionary storage device, 24
...Display device, 26... Arithmetic control device.

Claims (1)

[Claims] 1. A means for extracting strokes, their positions and sizes from a master character pattern, a means for displaying the extracted stroke pattern, a means for storing stroke information for synthesizing a standardized stroke pattern, and an operator. A means for inputting a stroke code, and a method for determining strokes corresponding to the stroke code input by the operator and patterns of strokes belonging to the same classification based on stroke information and stroke size and position information extracted from the master character. The present invention is characterized by comprising means for synthesizing, and means for matching the synthesized stroke pattern with a stroke pattern extracted from a master character, and registering the stroke code of the synthesized stroke with the highest degree of matching in a character dictionary. A character dictionary creation method.