JPH02187885A - Character recognizing device - Google Patents

Abstract

PURPOSE:To enhance a recognition rate by obtaining an inclination from an input character using the centroid of the character and executing correction. CONSTITUTION:Points at equal intervals are obtained from the coordinates of the inputted character by a CPU 2. Respective averages of the x-coordinates and the y-coordinates are obtained from the obtained points at equal intervals, and a centroid G0 11 of the whole of the input character is obtained and stored in a whole centroid memory 4d. Next, another centroid is obtained only from some points at equal intervals having y-coordinates larger than a y-coordinate y0 of the centroid G0 11, and an upper centroid G1 12 is obtained. An inclination theta13 is obtained from the two centroids G0 11 and G1 12, and the input character is corrected from the inclination theta 13. Feature points composed of a start point, an end point, a sharp point, etc., are obtained from the corrected input coordinates and stored in an input feature memory 4c. According to the matching between these feature points and feature points registered in a recognition dictionary 5, feature points in the dictionary 5 closest to the input character are displayed on a display part 6 as the recognized result.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a character recognition device that recognizes slanted characters.

[Prior Art] Conventionally, character recognition devices extract features from input characters and perform recognition by matching the extracted characters with registered patterns registered in a dictionary.

[Problem to be solved by the invention] However, there are various ways of predicting handwritten characters depending on the person, and especially when the characters are written at an angle, when matching with a dictionary, the input characters are at an angle. Since the registered pattern is not tilted, erroneous recognition occurs, and the above conventional example has a problem in that the recognition rate decreases.

[Means and effects for solving the problem] In order to solve this problem, the character recognition device of the present invention detects the center of gravity of a character input from a character input unit and the center of gravity of a portion divided by a straight line passing through the center of gravity. This method is characterized by detecting the angle of inclination of the character using the detected angle of inclination, and correcting the input character or registered pattern.

[Operation] In such a configuration, the recognition rate can be increased by correcting the tilt angle.

[Embodiment] Fig. 6 shows an external view of the character layer a device of this embodiment, where ■ is an input ben of the input section, ■ is a transparent tablet, and a liquid crystal display DISP is installed below it. MIA is a menu area used when giving instructions for correction, editing, etc.
CIA is a character input area used for character input, and P is a printer.

The block diagram shown in FIG. 6 is shown in FIG.

FIG. 1 shows a hardware configuration diagram of the character recognition device of this embodiment. 1 is an input unit such as a tablet, 2 is a CPU for arithmetic processing, 3 is a ROM that stores the processing program of the CPU 2 shown in FIG. 5, 4 is a RAM for auxiliary storage, and input points obtained from the input unit 1 an input coordinate memory 4a that stores the X coordinate, an input coordinate memory 4a that stores the An upper center of gravity memory 4e stores the center of gravity calculated from equally spaced points having an X coordinate larger than the X coordinate of the center of gravity stored in the overall center of gravity memory 4d, and an overall center of gravity memory 4d. 4d and upper center of gravity memory 4e
It includes a tilt person memory 4f for storing the tilt angle of each character calculated from the center of gravity of each character stored in the memory, and a work memory 4g necessary for executing the thin character recognition.

5 is a recognition dictionary used for character recognition; 6 is a display unit for displaying character recognition results, and includes a display memory for storing display data such as character recognition results.

Figure 2 shows the input characters in 3 and the calculated 2 in this example.
FIG. 2 is a diagram showing a center of gravity, an inclination angle, and a character frame. In the figure, lO is the input character, 11 is the center of gravity of the entire input character, 12 is the center of gravity of the input character above the entire center of gravity 11, 13 is the tilt angle θ, and 14 is the character frame. .

FIG. 3 is a diagram showing a character frame, an X axis, a y axis, a center of gravity, and an inclination angle in this embodiment. In the figure, 20 indicates the X-axis and 21 indicates the y-axis.

FIG. 4 is a diagram showing details of the recognition dictionary 5, in which character coats and feature point coordinates are described.

Next, the character recognition process of the stirrup according to the present embodiment having the above configuration will be explained with reference to the flowchart shown in FIG.

First, in step S30, characters are input via the tablet 1 using a pen operated by an operator. The coordinates of the input characters are sequentially stored in the input coordinate memory 4a in the subsequent step S31, and when it is confirmed in step S32 that one character has been completed, the process advances to step S3°3. - If character input is not completed, step S32 to step S
Return to 30. In step S33, equally spaced points are determined from the coordinates of the characters input by the CPU 2. First, connect the input points with a straight line for each stroke, extract points on the straight line at regular distances from the starting point (these points are called equally spaced points), and store them in the equally spaced point memory 4b. Next, in step S34, the average is taken for each X coordinate and X coordinate from the equally spaced points obtained in step S33, and the overall center of gravity G o (X a , 'Y o) in FIG. Store in. Step S35 is step S3
The y-coordinate y of the entire center of gravity Go (Xo, yo) found in step 4
. The center of gravity is determined only from equidistant points with X coordinates larger than , and the upper center of gravity G + (x + , y +
seek. In the following steps S36 and S37, 2
One center of gravity G. .

G, calculate the inclination angle θ using the following formula, and find that the inclination angle is -30
If <0<30, proceed to step 33B and -30〈θ〈
If it is outside the range of 30, step here to set the inclination angle to -30〈θ
The reason for setting <30 is to ensure that input characters are not tilted to an extreme degree. In step 338, the input character is corrected based on the obtained tilt angle θ. Each input point stored in the input coordinate memory 4a is the overall center of gravity G. (xo
, yo) Replace the coordinates obtained by rotating the center so that the inclination angle θ becomes zero with the initial input coordinates stored in the input coordinate memory 4a. In the following step S39, feature points consisting of a starting point, an ending point, a cusp, etc. are determined from the corrected input coordinates and stored in the input feature point memory 4C.

By matching this feature point with the feature points registered in the recognition dictionary 5, the one closest to the input character in the recognition dictionary 5 is set as the recognition result, and in the next step S40, the display unit 6 (
Display is performed via the Display.

[Embodiment 2] A character recognition device extracts feature points of an input character before step S33 in FIG. 5 of Embodiment 1, and performs character inclination angle correction using the extracted feature points.

[Embodiment 3] A character recognition device that corrects the recognition dictionary 5 instead of correcting the inclination of the input character in step S38 in FIG. 5 of the first embodiment, and performs character recognition in step S39.

[Example 4] In step S35 of Fig. 5 of Example 1, instead of finding the center of gravity of the upper part of the input character, the lower part (part smaller than yo)
, or a character recognition device that calculates the tilt angle using the center of gravity of a portion other than the upper side, such as the right side (portion larger than xo) or the left side (portion smaller than xo), and performs correction.

[Effects of the Invention] As described above, according to the present invention, the inclination angle is detected from the input character using the center of gravity of the character and corrected, thereby increasing the recognition rate.

[Brief explanation of the drawing]

FIG. 1 is a hardware configuration diagram of a handwritten character recognition device according to an embodiment of the present invention. FIG. 2 is a diagram showing input characters, two detected centroids, tilt angles, and character frames. Figure 4 is a diagram showing the character frame, X axis, y axis, center of gravity, and inclination angle. Figure 4 is a diagram showing a recognition dictionary. Figure 5 is a flowchart of character recognition processing of the device of this embodiment. Figure 6 is this embodiment. FIG. 2 is an external view of the character recognition device of FIG. 1 is an input unit, 2 is a central processing unit (CPU), 3 is a read-only memory (ROM), and 4 is a random access memory (
RAM), 5 is a recognition dictionary, 6 is a display unit, 10 is an input character, 11 is the center of gravity of the entire input character, 12 is the center of gravity of the part of the input character above the entire center of gravity 11, 13 is an inclination angle, 1
4 is a character frame, 20 is an X axis, 21 is a y axis, 41 is an input bench, 42 is a transparent tablet, 43 is a menu area, 44 is a character input area, and 45 is a printer.

Claims (1)

[Claims] A character recognition device that inputs and recognizes written characters detects the center of gravity of the input character and the center of gravity of a portion divided by a straight line passing through the center of gravity, and uses these to detect the inclination of the character. A character recognition device characterized by having means for determining and correcting corners.