JPS61188676A - System for cutting out symbol area - Google Patents

Abstract

PURPOSE:To reduce the rate of identification error by providing a symbol position deviation correcting circuit and acting a position deviation detecting window on a circular symbol of a circular symbol area where identification has resulted in failure. CONSTITUTION:When a symbol identification resulted in failure during initial symbol cutting out and identification, it is judged by use of the symbol position deviation correcting circuit 6 whether the number of times of failure is one. If the result is affirmative, the circuit 6 shifts the position deviation detecting window to left and right and up and down within the allowance of deviation to find a position for which the total area is filled with black pixels. The deviation or positional deflection in the left to right or vertical directions is found and the deviation is used to cause the circular symbolic area cut-out circuit 4 to perform a second symbol cutting out operation. By this, the symbol area to be cut out is corrected to enable identification processing to be performed in correct state to reduce the identification error rate.

Description

[Detailed description of the invention] [Industrial application field].

The present invention relates to an improvement in a symbol region extraction method.

□ In a pattern recognition device, it becomes necessary to cut out a region including a symbol, for example, a circular symbol, included in the pattern and subject it to recognition processing. Of course, such a device, for example, a graphic input processing device, uses an input device such as a drum scanner to read a drawing containing a mixture of circular symbols, single line characters, etc., and is capable of not only recognizing circular symbols, but also describing line segments, separating characters, etc. It goes without saying that the extraction must be carried out, ``--If the extraction of such a symbol area can always be done properly, no problem will arise as far as the extraction is concerned, but in reality, Since there are cases where this is not always the case, it is necessary to take precautions.

[Prior Art] ′ The conventional way of dealing with the positional deviation of a symbol in a graphic input processing device is to perform feature extraction that allows the deviation in the identification unit to avoid the inconvenience caused by the positional deviation of the symbol. There wasn't.

[Problem that the invention seeks to solve]

Therefore, no consideration has been given to the positional deviation in the cut-out portion of the symbol area.

Therefore, the identification error rate due to positional deviation has inevitably increased.

[Means for solving problems]

The present invention provides a method for cutting out a symbol area that can solve the above-mentioned problems, and the method is to cut out a symbol area when identifying a symbol in a pattern including symbols. means for detecting the amount of positional deviation by applying a positional deviation detection window to the symbol in the symbol area used for identification in response to the identification; and means for storing the symbol area corrected by the amount of positional deviation as a pattern. and means for cutting out the material and making it available for identification by the identification means.

[Effect]

According to the method of the present invention, even if identification of a symbol by the identification means is unsuccessful, the detected amount of positional deviation is applied to the symbol in the symbol area cut out including the symbol to correct the amount of positional deviation. This positional shift amount is used to re-cut out the symbol area in which the symbol is in the normal position and use it for identification, making it possible to lower the identification error rate.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the invention. In this figure, 1
1. An image is captured by an image input device≠
The initial image data is stored in a storage location of the image memory 3 under the address control of the address control section 2. 4 is a circular symbol area cutting circuit, which is connected to the address control unit 2.
A symbol area including a circular symbol is cut out from the image data in the image memory 3 under address control.

The details are detailed in the patent application filed in 1983, which has already been proposed by the present applicant.
See the disclosure in No. 103,875.

Reference numeral 5 denotes a circular symbol identification circuit, which identifies circular symbols within the symbol area cut out as described above, and its details are described in Japanese Patent Application No. 166642, which was already proposed by the applicant. Please refer to the disclosure.

Reference numeral 6 denotes a symbol position deviation correction circuit, which, when identification is unsuccessful in the circular symbol identification circuit 5, adjusts the address of the address control unit 2 to the circular symbol in the circular symbol area where the identification was unsuccessful. The amount of positional deviation is detected by operating a positional deviation detection window.

The symbol extraction aspect of the present invention configured as described above will be explained below.

Initial extraction of image data containing circular symbols stored in the image memory 3 from the image input device 1 is performed in the circular symbol area extraction circuit 4 under the address control of the address control section 2 (81 in FIG. 2). Identification of the circular symbol ε in the symbol area is performed by the circular symbol identification circuit 5 (82 in FIG. 2), and as long as the identification is successfully performed, the function of the present invention will not be activated (see FIG. 2). No. 83). 4 Such an initial cut,! Suppose that while the lk classification is being performed, the initial extraction becomes as shown in Figure 3, and the symbol identification ends in failure (YES in 83 in Figure 2).
).

Then, the symbol position deviation correction circuit 6 comes into operation. This circuit 6 performs the following processing.

It is determined whether the number of failures is the first time (
84 in Figure 2), the result is negative (No. 84 in Figure 2)
), the process is to make the identification ultimately unsuccessful; however, if it is affirmative (YE of 84 in Figure 2)
S), perform the following symbol position shift correction process (
35 in Figure 2).

The positional deviation detection window as shown in FIG.
1, II) or vertically (m, IV) with a width of d (tolerable positional deviation) from the outside of the area to the inside to detect a position completely filled with black pixels. Then, the horizontal direction (window area I and ■) or the vertical direction (window area
Find the deviation (positional deviation amount) from the center position of (
(See Figure 5).

Using this positional shift amount, the circular symbol area extraction circuit 4
This causes another symbol extraction process. Then, the symbol area to be cut out is corrected and the 6th r!
! As shown in J, this makes it possible to identify objects in the correct state, thereby reducing the identification error rate. The causes of failure in circular symbol identification are: 1. Misalignment of the symbol.

Most of the image defects (fading, paper smearing, etc.) are due to the positional deviation of the symbols, so it can be expected that the identification error rate will be reduced by correcting the positional deviation.

In the above embodiment, the case where a rod-shaped window is used has been described, but other shapes such as those that are the same as or partially coincide with a circular symbol may also be used. Furthermore, depending on the shape of the symbol and/or the window, the number of times of cutting may be set to a plurality of times in order to use the one with the minimum amount of positional deviation.

[Effects of the Invention] - As explained above, according to the present invention, it is possible to: 1) provide a means for cutting out a symbol area in a position where an identification symbol can be successfully identified; and 2) reduce the identification error rate. Effects such as "obtain" can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a first embodiment of the present invention.
l A flowchart for explaining the embodiment, FIG. 3 is a diagram showing an example of initial extraction, FIG. 4 is a diagram showing a positional deviation detection window, and FIG. 5 is a symbol area extracted with a horizontal deviation. FIG. 6 is a diagram showing the symbol area in a state where the positional shift in FIG. 5 has been corrected. In the figure, 1 is an image input device, 2 is an address control unit,
3 is an image memory, 4 is a circular symbol area extraction circuit, and 5 is a circular symbol area extraction circuit.
6 is a circular symbol identification circuit, and 6 is a symbol position deviation correction circuit. Figure 1 #j 2 Figure 31! Figure 4 Figure 6 #j 5 Figure fu

Claims (2)

[Claims] (1) In a method of cutting out a symbol area when identifying a symbol in a pattern including symbols, in response to failure of identification by the symbol identification means, a position shift detection window is applied to the symbol in the symbol area used for the identification. and a means for cutting out a symbol area corrected by the amount of positional deviation from the pattern storage means and making it available for identification by the identification means. Symbol area extraction method. (2) The symbol is a circular symbol, and the positional deviation detection window can include at least a predetermined amount of symbol pixels when acting on the circular symbol. The symbol area extraction method described in Section 1.