JPH06187501A - Handwritten character/graphic recognizing - Google Patents

Abstract

PURPOSE:To provide a handwritten character/graphic recognizing system which can satisfactorily recognize the handwritten characters and graphics even when no rectangular area is shown on an input screen. CONSTITUTION:A handwritten character/graphic recognizing system includes an input means 3 which reads handwriting input stroke information, a recognizing means 7 which secures the matching with a dictionary based on the feature value of the input stroke information and recognizes the characters and graphics, and a display means 2 which shows the input stroke information and the recognizing results. The means 7 performs the matching for each input of the input stroke information and then repeats the matching with the next input stroke information if no matching is secured with the first input stroke information. As a result, the handwritten characters and graphics are satisfactorily recognized with higher operability even when no rectangular area is shown on an input screen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handwritten character / graphic recognition system, and more particularly to display of stroke information input by handwriting and display of recognition result.

[0002]

2. Description of the Related Art As a handwriting recognition system, Japanese Patent Laid-Open No.
As shown in Japanese Patent No. 144287, the character recognition system is the main one. In the handwritten character / figure recognition system in which characters and figures are mixed, technical suggestions or concrete suggestions on how to display the stroke information input by handwriting and the recognition result are now available. Not so far.

In the above-mentioned Japanese Laid-Open Patent Publication No. 58-144287, the input surface is divided into a plurality of rectangular areas, and strokes are displayed in the rectangular areas. The inside of the rectangular area was changed to a recognition display.

As a result, the stroke before recognition was automatically erased in units of rectangular areas.

However, in a handwritten character / graphic recognition system in which not only characters but also graphics are mixed, if the recognition display is changed in units of rectangular areas, the following problems occur.

(1) When a handwritten character is written on a graphic line, in order to erase the handwritten character stroke, it is necessary to change the recognition display to a rectangular area unit, and as a result, as a graphic in the rectangular area. The line is cut. This state is shown in FIGS. 1A and 1B, where FIG. 1A shows before recognition and FIG. 1B shows after recognition.

(2) If the figure is input by stroke and the recognition result is controlled to be displayed, the stroke display cannot be erased. In other words, the figure recognition does not employ a recognition method in units of rectangular areas, unlike the character recognition. Therefore, if only the recognition result is displayed, other recognized characters may be erased, and the recognized strokes may be deleted. It becomes impossible to erase only the information.

This situation is shown in FIGS. 1 (c) and 1 (d).

(C) shows the display before the recognition of the handwritten figure input stroke, and (d) shows the display after the recognition that the handwritten figure input stroke remains unerased.

On the other hand, if all strokes are erased when the recognition result is displayed, there is a problem in that strokes that have not been recognized may be erased.

[0011]

In the above prior art, a plurality of rectangular areas are displayed in advance on the input surface, and the recognition of the input stroke and the erasure of the input stroke, which is the handwriting, are executed for each rectangular area. Yes, the input stroke is cut out for recognition by cutting out the input stroke existing in the first rectangular area when the stroke input is transferred from the first rectangular area to the next rectangular area. It is what you do. Therefore, in the case where the rectangular area is not displayed on the input surface, the input stroke cannot be cut out and recognized.

It is an object of the present invention to provide a handwritten character / graphics recognition system capable of satisfactorily recognizing characters / graphics even when a rectangular area is not displayed on the input surface.

[0013]

DISCLOSURE OF THE INVENTION According to the present invention, input means for reading stroke information of characters / graphics input by handwriting, and a character / graphic by performing matching with a dictionary using the feature amount of the read input stroke information. In a handwriting character / graphics recognition system having a recognition means for recognizing, and a display means for displaying the input stroke information and the recognition result obtained by the recognition means, the recognition means comprises:
Each time the stroke information is input by the input means, it is matched with the dictionary, and if the result of the matching is that they do not match, the matching is performed again with the next input stroke information.

[0014]

According to the present invention, each time stroke information is input, matching is successively performed with the dictionary, and if the matching results match, the recognition result is displayed. If there is no match as a result of matching, matching is performed with the stroke information input next, and similar processing is repeatedly executed until a recognition result is obtained. As a result, even when the rectangular area is not displayed on the input surface, the recognition is performed each time the stroke information is input, so that the input stroke information is automatically cut out and recognized. It is possible to improve.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is an overall configuration diagram of an embodiment of the present invention. 1 is an electromagnetic induction type stylus pen, 2 is a liquid crystal display, 3 is an electromagnetic tablet, 4 is a processing device, 5 is a frame memory, and 6 Is a display control device, 7 is a handwritten character / graphic recognition device, and 8 is a cover.

FIG. 3 is a time chart for explaining the operation of FIG. 2. (A) is the operation of the electromagnetic tablet 3, (B),
(D), (E) and (F) show the operation of the handwritten character / graphic recognition device 7, and (C), (G) and (H) show the operation of the processing device 4.

When a stroke is input from the stylus pen 1 that outputs an electromagnetic wave from above the liquid crystal display 2, the electromagnetic wave passes through the liquid crystal display 2 and reaches the electromagnetic tablet 3, and the coordinates of the input point are read. These input coordinates are sequentially transferred from the electromagnetic tablet 3 to the bus 10
It is sent to the handwritten character / graphics recognition device 7 (hereinafter abbreviated as recognition device) via 1 (process of FIG. 3A).

In the recognition device 7, in order to display the stroke, the input coordinates are input to the processing device 4 via the bus 102.
The coordinates are converted and transmitted (FIG. 3 (B)). In the processing device 4,
In order to display strokes on the liquid crystal display 2,
The previously input coordinates and the coordinates input this time are written in the corresponding coordinates of the frame memory 5 so as to connect them with a straight line (FIG. 3 (C)), while the recognition device 7 is handwritten based on the input strokes. Recognition is performed (FIG. 3D), and if the figure or character in the dictionary (not shown) does not match, input of the next input stroke is waited for (FIG. 3E). If they match,
The recognition result is sent to the processing device 4 via the bus 102 ((FIG. 3 (F)). In this case, not only the recognized figure or character code but also the input stroke is recognized as will be described later. The processing device 4, which has received the recognition result, first of all, based on the information of how much of the input stroke is recognized, the bus 1
A command for deleting the recognized stroke from the frame memory 5 is output via 03 (FIG. 3 (G)).

Further, the processing device 4 writes the recognition result in the frame memory 5 via the bus 104 (FIG. 3 (H)).

The contents of the frame memory 5 are constantly read by the display controller 6 at a frequency of 60 Hz or more and sent to the liquid crystal display 2 via the buses 107 and 108, so that the change in the frame memory 5 is instantaneous. Is displayed on the liquid crystal display 2.

The above is the outline of the overall operation. Next, the detailed operation of each part will be sequentially described below.

(1) Input coordinate reading The electromagnetic tablet 3 receives the electromagnetic wave from the stylus pen 1 and detects the coordinates of the pen tip as described above. For the tablet and pen, for example, DT-4010 manufactured by Seiko Denshi Co., Ltd. can be used, and details of the principle thereof are described in, for example, Transistor Technology May 1983 issue.

In addition to the coordinate information of the pen tip, it is possible to read the information as to whether the pen is pressing the liquid crystal display 2 or the cover 8 or not. Then, through the bus 101, the absolute coordinates of the electromagnetic tablet 3 and the information as to whether the pen is pressed (pen down status) or not (pen up status) are input to the handwritten character / graphic recognition device 7.

(2) Operation of the handwritten character / figure recognition device 7 In FIG. 4, the electromagnetic tablet 3, the display section of the liquid crystal display 2, the positional relationship seen from above the liquid crystal display section, and the frame memory 5 are shown. The relationship of the areas instructing whether to display the part is shown. The electromagnetic tablet 3 can input the coordinates of the entire area of FIG. 4, and the handwritten character / graphics recognition device 7 changes the tablet coordinates input from the bus 101 to
Based on the positional relationship of FIG. 4, a process of separating the coordinates in the liquid crystal display unit, the coordinates of the display position designating area, the coordinates of the 1/2 display area, and others is performed. The display position designating area and the 1/2 display area are provided because the liquid crystal display unit is small and the entire frame memory 5 cannot be displayed. Specifically, 640 × 256 dots in the frame memory 5 having 1280 × 1024 dots are displayed on the liquid crystal display 2, and the upper left coordinates to be displayed are the display position designation area, and 1280 × 512 dots are 1 / Two
The display reduced in size can be specified by pressing the 1/2 instruction area with a pen. This information is available on bus 109
Is sent to the display control device 6 via the, and the read address of the frame memory 5 is changed.

On the other hand, the operation when the liquid crystal display section of FIG. 4 is depressed with the pen will be described below.

The input coordinates (X, Y) of the electromagnetic tablet 3 are
Coordinate conversion formula for coordinates (x, y) in the frame memory 5

[0027]

[Equation 1]

Is converted by Here, M is a constant that is 1 for normal display and 2 for 1/2 reduced display,
(A, b, c, d) are conversion matrix coordinates for converting the tablet coordinates into the coordinates of the liquid crystal display surface,
(X ₀ , Y ₀ ) are reference coordinates indicating from which position of the frame memory 5 the liquid crystal display 2 is displayed.

The converted coordinates (x, y) are pen up / pe
It is sent to the processing device 4 via the bus 102 together with the status information of n down.

On the other hand, (X, Y) coordinate information and pen up
The handwritten character / figure recognition device 7 performs handwriting recognition based on the / pen down status information.

First, input stroke pen up / pen down
Information is used to separate input coordinates into stroke units.
This is because the stroke starts when the pen up state is changed to the pen down state until now, and the input coordinates are stacked, and when the pen up is performed again, the stroke ends. When one stroke is input, recognition is performed using the stacked coordinate information.

If there is no match with the defined dictionary in the dictionary, the input of the next stroke information is awaited. If there is a match, the result is sent to the processor 4 via the bus 102.

FIG. 5 shows a transmission data format of the recognition result. (A) is the above-mentioned format for transmitting coordinate information, which is a flag Fl that indicates coordinate information transmission.
PEN indicating up / down information of agA and pen and coordinates (x,
y) is sent. (B) is a format for transmitting the character recognition result. In this case, the flag FlagB indicating the character recognition transmission and the stroke number n used for recognition
And the recognized character code CHAR and the character size,
SIZE & LOCATION indicating the written position is sent.
(C) is a format for showing the result of figure recognition. In this case, almost the same as in the case of character recognition, the difference is that the recognized graphic code CODE is sent out.

Although the recognition result is sent to the processing device 7 in the above format, the stroke n used for recognition is used.
Is characterized in that

(3) Operation of processing device FIG. 6 shows the internal structure of the processing device 4.
Receiver circuit 61 which is an interface with the figure recognition device 7.
And an arithmetic circuit 62 having an arithmetic register and two first-in and first-out (F
IFO) memory circuits 64, 65 and memory circuits 64, 6
5 Input pointers 68 and 70 and output pointer 6 respectively
7, 69 and an output circuit 63 to the frame memory 5. The memory circuit 64 can store and read the number of coordinates (electric number) forming one stroke, and the unit 65 can store and read coordinate information of x, y1 sets.

The arithmetic circuit 62 has a register for storing the number of coordinates m and p, a state indicating the state, coordinates (α, β), (γ, δ), and a register for holding the received data. However, addition / subtraction, control of the memory circuits 64 and 65, and control of the output circuit 63 can be performed using these.

7 and 8 are flow charts showing the operation of the arithmetic circuit 62, and the operation will be described below with reference to this flow chart.

After the initialization (FIG. 7 (a)), the input from the receiving circuit 61 is waited for (FIG. 7 (b)). When there is an input, the following processing is performed using the input data of FIG. First, the flag received in (c) and (d) is checked.
When the flag is coordinate input, it is checked in (f) of FIG. 8 whether the pen is up or down. In the case of pen-up, after displaying the cursor at the input coordinates (x, y) (Fig. 7 (j)), it is checked whether or not stroke input is in progress. If stroke input is not in progress, the process returns to the next coordinate input wait ( FIG. 8 (g)).

If pen-up is detected during stroke input, it means that stroke input is completed. Therefore, the state is initialized and a stroke is formed.
After writing the number m of (x, y) coordinates in the FIFO 64 by using the input pointer 68, the input pointer 68 is incremented by 1 to initialize m (FIG. 8 (h)).

At the time of pen down in FIG. 8F, it is checked whether the state is initialization (FIG. 8).
(k)) At the time of initialization, the state is changed to the stroke input mode to indicate that the stroke input has started (FIG. 8 (m)). On the other hand, during stroke input, a straight line connecting the last input coordinate of the FIFO 65 and the currently input coordinate (x, y) is output (FIG. 8).
(l)). Furthermore, regardless of the mode, the input coordinates (x,
y) is written in the FIFO 65, and the value m indicating the number of coordinates forming the input pointer 70 and the stroke is updated (FIG. 8 (m)).

By performing the above processing, the FIFO
64 is the number of coordinates of each stroke, and FIFO 65 is
The values at coordinates (x, y) are stacked.

When the flags are B and C, the following processing is performed in order to erase n strokes.

First, the coordinate number p of the first stroke is read from the FIFO 64 and the output pointer 67 is updated (FIG. 7 (o)). Furthermore, from the FIFO65, the first coordinate
(α, β) is read and the output pointer 69 of the FIFO 65 is read.
Is updated and p is decremented by 1 (FIG. 7 (p)). Further, the next coordinates (γ, δ) are similarly read (FIG. 7 (r)), (α,
The line connecting (γ, δ) from (β) is deleted. After erasing,
By substituting (γ, δ) into (α, β) (FIG. 7 (s)), the next straight line is erased until the stroke coordinate number p is reached (FIG. 7 (u)).

When the deletion of one stroke is completed, n is subtracted until the number of strokes used for recognition is reached.
The erasing is repeated (FIGS. 7 (v) and (x)).

By performing the above processing, only strokes for which recognition has been completed can be sequentially erased.

The output circuit 63 controls the output and deletion of strokes in the above flow. For output and erasure, the exclusive OR is used here for the frame memory 5
Implement by writing in.

The exclusive OR is output c for inputs a and b.
Is represented as shown in the table below.

[0048]

[Table 1]

Therefore,

[0050]

[Equation 2]

Therefore, when the exclusive OR is performed twice with the same value b, it has the property of returning to the previous value.

As a result, the coordinate F of the frame memory 5 is
When trying to write a point to (x, y) and always taking an exclusive OR with 1,

[0053]

[Equation 3]

It becomes If 1 is written again for further erasing,

[0055]

[Equation 4]

It becomes As a result, the value of F (x, y) returns to its original value and can be erased.

(4) Operation of the display control device 6 Since the display reference coordinates (X ₀ , Y ₀ ) and the instruction of normal display or 1/2 display are communicated via the bus 109, the frame memory 5 is informed. For the read address, the bus 106
Send through. Data from frame memory 5 is transferred to bus 1
When it is received via 05, the address 108 and the data 107 are sent to the liquid crystal display 2. As a result, the contents of the frame memory 5 are sent to the display 2.

As described above, according to the present embodiment, the stroke display corresponding to the recognition result can be erased before the recognition display, and the input and the output are integrated to input the stroke. The stroke information before recognition and the recognition result can be displayed at a place in time series, and man-machine performance is improved.

On the other hand, as another embodiment of the present invention, a method in which the processing device 4 also performs recognition, or a method in which the number of recognized strokes is communicated more finely rather than the number of recognized strokes is considered. To be

[0060]

According to the present invention, even if a rectangular area is not displayed on the input surface, the input stroke information is automatically cut out and recognized.
It is possible to improve operability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a problem of a conventional technique.

FIG. 2 is an overall configuration diagram of a system to which the present invention is applied.

FIG. 3 is a flowchart illustrating an operation of the system shown in FIG.

FIG. 4 is a layout diagram of an input integrated display.

FIG. 5 is a diagram showing a format of transfer data.

FIG. 6 is a block diagram of an embodiment of the processing apparatus shown in FIG.

7 is a flowchart illustrating an operation of the processing device shown in FIG.

8 is a flowchart illustrating an operation of the processing apparatus shown in FIG.

[Explanation of symbols]

1 ... Stylus pen, 2 ... Liquid crystal display, 3 ... Electromagnetic tablet, 4 ... Processing device, 5 ... Frame memory, 6 ...
Display control device, 7 ... Handwritten character / graphic recognition device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takanori Yokoyama, 3-1-1, Saiwaicho, Hitachi, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor, Kazuyoshi Koga, 3-chome, Hitachi, Hitachi, Ibaraki No. 1 in Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Kotaro Hirasawa 3-1-1, Saiwaicho, Hitachi, Ibaraki Hitachi in Hitachi Research Laboratory, Ltd. (72) Shinichi Kawada Chiyoda-ku, Tokyo 4-6, Sugatadai, Kanda Inside Hitachi, Ltd.

Claims (1)

[Claims] 1. Input means for reading stroke information of characters / graphics input by handwriting, and recognition means for recognizing characters / graphics by matching with a dictionary using the feature amount of input stroke information from the input means. In the handwritten character / graphics recognition system having a display unit for displaying the input stroke information and the recognition result obtained by the recognition unit, the recognition unit stores the dictionary in the dictionary each time the stroke information is input by the input unit. The handwriting character / graphics recognition system is characterized in that if the result of the matching does not match, the matching is performed again with the next input stroke information.