JPS60105083A - Character recognizing method - Google Patents

Abstract

PURPOSE:To ensure the stable extraction of strokes by adding the directionbased code to a character pattern, propagating the same direction code as long as the character pattern continues and using a feature parameter for each extracted stroke to recognize characters. CONSTITUTION:The writing is carried out to RAM1-6 via address controllers AC1-AC8 under the control of a controller CONT. The data on a subject character pattern is written to the RAM1. A direction code is added to the written character pattern by the program processing of a CPU through the controller CONT or the processing through the proper hardware. Then the character pattern containing the direction code is written to the RAM2. The controller CONT extracts strokes for each direction code according to the data on said character pattern to write the data on the strokes extracted with direction codes 0, 1 and 3 to the RAM3, RAM4 and RAM5 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a character recognition method that performs character recognition by extracting feature parameters for each stroke in a character pattern.

LLjJ t+1ir Generally, in order to perform character recognition using OCR, a character pattern is marked with a code 1- for each direction, strokes are extracted according to the code, and the characteristic parameters for each stroke are calculated to recognize the character. I try to do it. For example, if the character pattern in Figure 1 is processed using the conventional method, the direction code &
It will look like the figure. In that case, if one pixel worth of noise N is mixed into the character pattern as shown in Figure 4, if direction coding is applied to it as in the past, the result will be as shown in Figure 5. If only stroke extraction in direction 0 is performed for the two directions, the extracted strokes will be different as shown in FIG. However, it is common for noise to be mixed into character patterns when reading characters, and if a character recognition error were to occur each time, it would be difficult to perform character recognition (0 (: R function is significantly reduced.

Therefore, conventionally, in order to deal with such noise contamination, the number of dictionaries that correspond to the extracted stock feature parameters has been increased.

However, by increasing the term -J:, the storage capacity of the memory increases, and the correspondence time between the extracted feature parameters and the term 1'r increases, resulting in a long search time. Become. In that case, it is clear that unless the letter 8 is made larger, the recognition of the characters will deteriorate.

■The present invention was made with the following two points in mind,
To provide a character recognition method that can perform stable direction coding and stroke extraction without being affected by noise, and can accurately calculate character characteristic parameters. .

4th place An embodiment of the present invention will be described in detail below.

In the character recognition method according to the present invention, character patterns are coded according to direction, strokes are extracted according to the codes, and 1.1 characteristics are extracted for each extracted stroke. When character recognition is performed by determining parameters, a means is taken to extract strokes by propagating the direction code as long as the pattern continues in each direction.

For example, a case where stroke extraction is performed for the character pattern shown in FIG. 1 with direction codes added as shown in FIG. 2 will be described below. First direction code 0
With respect to

(1) Search for direction code O while rask-scanning in the j direction with respect to the direction coded, tt character pattern shown in FIG. 7 (part of which is shown in FIG. 2).

(When a 2+ direction code O is found, a code 0 is written to the pixel memory 1- shown in FIG. is X)
Then, it is checked whether direction code 0 exists at the position of pixel 0 adjacent to pixel X.

(3) As a result, if the direction code is 0, write the code 0 onto the corresponding pixel memory shown in FIG.

(4) If the direction code is not O, check whether the character pattern continues.

(b) As a result, if the character pattern does not continue, advance one pixel in the j direction and return to step (2) above.

(6) If the character pattern continues, write code 0 to the corresponding pixel memory "2" in FIG.

If the direction code 0 is propagated as long as the pattern continues in accordance with the procedure described in 1-1 above, strokes as shown in FIG. 8 will be extracted.

Regarding the other direction codes 1 to 3, in the same way, it is checked whether the same direction code or pattern exists at the position of the direction code shown in FIG. 9, and the direction codes are propagated as long as they continue. Then, the strokers for each direction code will be extracted.

Furthermore, in addition to the rask scan in the J direction, if the position of the direction code 1- shown in FIG. This can be done more completely by scanning.

In this way, by using the character iJJ recognition method according to the present invention,
Since the direction code I- is propagated for each direction code as long as the pattern continues, stable stroke extraction can always be performed without being affected by noise.

FIG. 11 shows an example of a configuration for visually implementing the character recognition method according to the present invention.
: Under the control of ONT, writing to each RAM 1-6 is performed via address controller 1-roller AC1-8C8. The data of the character pattern that becomes the object is written in the RAMI, and the character pattern is controlled by the character pattern 'i jff CO.
The direction code is determined by the CPU's program processing or by the processing by its own hardware.
The direction coded data of the lI,h character pattern is written into RAM2. Control device C7ON
T is the data of the oriented character pattern, but the strokes are extracted for each name direction code using the procedure described above, and the data of the strokes extracted by shifting to the direction 21-D O is extracted. 13 to RΔ, extracted with respect to direction code I 41. The stroker data 'RA~14
1. Extracted with respect to direction code 2. The stroke data extracted for direction code 3 is set to RA+ti5, and the stroke data extracted for direction code 3 is set to RΔMG41. Fortune-telling. Na, 13 At that time, there was a separate code for the old Ji! ~ If you can even calculate the characteristic parameters of the letters after the extraction of the letters (71),
1z A M 3~ Parameter data of characters drawn out instead of B [,:! +; 1 RA for loading
M may be used. Further, as shown in FIG. 12, the direction code of the pixel of interest is 7 according to the address bit output from control η1 and C0NT, and ΔM3' is 1. In order to write to the address of 111jl rll,
(The memory capacity of 't can also be substituted for RAMs 3 to 6 in Fig. 11 by adding -1 to R△13'. In addition, Fig. 13 shows the control in the control device C0NT. Flowchart 1-5 is shown in the character recognition method according to the present invention. By extracting one stroke per day, and calculating the characteristic parameters for each extracted stroke to perform character recognition, we can print out the same direction code once (as long as the pattern continues for each direction code). This allows stroke extraction to be performed stably without being affected by noise. : It has the excellent advantage of being able to efficiently perform character recognition with a large capacity and a short time interval.

FiI of the drawing! Explanation: Figure 1 shows an example of a character pattern to be recognized.
FIG. 2 shows the direction code 1 and the data state; FIG. 3 shows the direction code 1 (c+ -7) extracted with respect to direction code 0 by the conventional method; FIG. 6 shows the 1st to 31st+:4 Niso, 1[So:It'1.
Figure 7 is a diagram showing the presence of parts of Figure 2 and 3; Figure 9 is a diagram showing the direction code (:l HVl) when raster running H in the i JJ direction, Figure 10 is the -j force direction rough,
What if I run and fc? Figure 11 shows the location of the given direction code, and Figure 12 shows the structure for implementing the invention in an integrated manner. Block diagram showing each of the four examples, No. 13
The figure is the same Daishi 19! FIG. 3 is a diagram showing -i'ill of the control flow of the control i device in l.

CONT/control equipment! ti, Ac1~A C,3・Al
Hellescon 1-Lola J] Entrepreneur's Agent Karasui Nko 21°f? +>, 11 Fig. 81 concave Fig. 9 ':j';101'A Fig. 11 hl M3 Fig. (a) Fig. 13 (b) Fig. 13 (d) Fig. 13 (e)

Claims (1)

[Claims] 1. After creating a code for each direction (=J) in the character pattern, strokes are extracted according to the codes 1 to 1 in each direction, and the characteristic parameters of each stroke turtle are calculated based on the extracted strokes. A character recognition method characterized in that stroke extraction is performed by propagating the same direction code for each direction code as long as the pattern continues.2. 49, character recognition method using a bar, characterized in that the propagation is made to be carried out in one direction only. The character recognition method according to item 1 above, characterized in that: