JPS6111890A - Forming method of reference pattern in picture recognition - Google Patents

Abstract

PURPOSE:To form exactly a reference pattern in an extremely short period by forming previously a temporary reference pattern then forming automatically a real reference pattern on the basis of the temporary reference pattern. CONSTITUTION:A binary pattern is formed around the center of a pattern 12 obtained from a designed value and inputted to a dictionary pattern memory as a temporary reference pattern 15. An arithmetic processing part executes the picture recognition of a pattern 13 separated from a picture memory and the temporary reference pattern 12 stored in the dictionary pattern memory on the basis of a pattern matching method. When the highest correlation between both the data is obtained, the identification of the temporary reference pattern 12 with the pattern 13 is obtained. Then, the pattern 12 is registered in a dictionary pattern memory as a real reference pattern 17.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image recognition method, and particularly to a method for creating a reference pattern in an image recognition method.

[Technical background of the invention and its problems]

2. Description of the Related Art Conventionally, there has been a pattern matching method as an image recognition method for correlating and matching a target pattern obtained from a photoelectric conversion device with a reference pattern.

Normally, the reference pattern detected by this image recognition method is
For example, an ITV camera images a target member, the resulting image information is reproduced on a monitor TV screen, and the target member or IVT camera is moved to first create an appropriate pattern corresponding to the target member or a specific portion of the target member. Select. After that, a pixel area of a predetermined size was cut out based on this pattern, and this was imported into a memory or the like and registered.

However, this method for producing a reference pattern has disadvantages in that it takes a long time to select the pattern and finely position the selected pattern, and it also causes variations due to individual differences among operators.

One way to solve this problem is to create a reference pattern by calculation from design dimensions obtained from drawings, etc., but this method usually involves errors in the optical magnification of the photoelectric conversion device and its mounting position. , it is not possible to easily create an accurate reference pattern.

[Purpose of the invention]

An object of the present invention is to provide a method for automatically and accurately creating and registering a reference pattern by absorbing errors in the optical magnification of a photoelectric conversion device and its mounting position.

[Summary of the invention]

First, a temporary reference pattern is created by calculation based on the design dimensions of the object and the optical magnification of the photoelectric conversion device. Thereafter, the target pattern obtained from this temporary reference pattern is identified and the position of the target pattern is recognized. Then, a true reference pattern was created from the identified and position-recognized target pattern, and this was registered.

[Embodiments of the Invention] The present invention will be described below based on embodiments with reference to the drawings.

First, the image recognition device will be described. As shown in Fig. 2, this image recognition device consists of a photoelectric conversion device consisting of an ITV camera (2) installed in front of the target member (1) so as to keep it in its field of view, and a photoelectric conversion device that transmits signals from the ITV camera (1). an image recognition circuit (3) that processes an image information signal to be processed;
It has a monitor television (4) that reproduces images captured by the TV camera (1). The image recognition circuit (3) includes a binarization circuit (5) that binarizes the image information sent from the ITV camera (2), and a binarization circuit (5) as shown in FIG. An image memory (6) that temporarily stores binarized image information, a dictionary pattern memory (7) that stores reference patterns, and these memories (6), (7)
), and a determination circuit (9) that determines the result of the calculation in the calculation processing unit (8).

Now, it is assumed that among the specific parts (lla), (llb), and (lie) of the target member (1), a specific part (lla) is detected as a target using this image recognition device. For clarity of explanation, the design specific part (lla) is a circle with a diameter of 2 mm, and the image recognition device is designed so that the optical magnification of the ITV camera (2) is set for the target member (1) in the correct position. Assume that the upper value is 0.05 mm/pixel. In addition, the actual optical magnification is assumed to be 0.052 mm/pixel due to manufacturing errors and positional deviations of the ITV camera (2), based on the above design values as shown in Figure 1A. Pattern of specific part (lla) obtained (12)
According to the calculation, should be a circular shape with a diameter of 40 pixels. However, as shown in Figure 1B, which is a screen image of the target member (1) taken with the IT, V camera (2),
The pattern (13) of the specific portion (lla) obtained from the V camera (2) has a circular shape with a diameter of 38 pixels. Moreover, if there is any processing unevenness in the actual specific portion (lla), its shape will be distorted compared to the pattern (12) obtained from the design values.

Therefore, in the reference pattern manufacturing method of the present invention, first, as shown in FIG. (12)
A binarized pattern with a diameter of 40 pixels is prepared, and this is imported into the dictionary pattern memory (7) shown in FIG. 3 as a temporary reference pattern (15). The ITV camera (2) then passes the image memory (6) through the binarization circuit (5).
) Image information of the same size as the temporary reference pattern (I2) (64 pixels x 64 pixels) is sequentially cut out from the image information of the target member (1) stored for one hour in the image memory (6). The image information cut out from the image information and the temporary reference pattern (12) imported into the dictionary pattern memory (7) are
An arithmetic processing unit (8) performs image recognition using a pattern matching method. Thus, the detection (identification) of the pattern (13) of the specific portion (lla) shown in FIG. It is obtained by calculating the number of matching bits of both data and finding the highest correlation. The position of the pattern (13) detected in this way is the pattern (13) that matches the orthogonal axes X and Y passing through the center of the temporary reference pattern (12) when both data have the highest correlation. Orthogonal axes Xa, Y
Indicated by a. Therefore, using the orthogonal axes Xa and Ya as a reference, a reference pattern area of 64 pixels and 4 pixels of Xa is cut out as shown by the broken line (16) in the figure, and this is used as the true reference pattern (17) as shown in Figure 1c. It is registered in the dictionary pattern memory (7) as follows.

In addition, in FIG. 1B, (18) and (19) are the specific parts (llb) and (l) of the target member (1), respectively.
lc) pattern.

In addition, in actual image recognition, after determining the true reference pattern (17) as described above, the reference pattern (17) of the board is determined.
This is performed using the same method as the method of detecting the specific portion (lla) based on 2).

When the reference pattern is produced as described above, the required reference/standard pattern can be produced accurately in a short time. That is, in the conventional method, the operator selects a pattern and creates a reference pattern from the selected pattern, which takes time and causes variations in the reference pattern due to individual differences among operators.
A temporary reference pattern is created in advance based on the design values, and then a true reference pattern is automatically created based on this temporary reference pattern, which completely eliminates the drawbacks of the conventional method and is extremely short. A required reference pattern can be produced accurately in a timely manner.

Furthermore, since the reference pattern is accurate, image recognition can be performed accurately.

In addition, since the reference pattern can be created extremely easily and in a short time, it is easy to update the reference pattern, and errors in image recognition are prevented by always using a reference pattern that matches the pattern obtained from the photoelectric conversion device. can do.

Next, other embodiments will be described.

In the above embodiment, a circular object was selected to create the reference pattern, but the object may be any object that can be clearly distinguished from other patterns, and is not limited to a circular shape.

In addition, in the above embodiment, the pattern matching method was applied to the reference pattern4, but other methods such as a method of calculating from the center of gravity and area may also be used as long as the shape and position of the pattern are compared with the reference pattern. good. In short, if the target pattern actually obtained from the photoelectric conversion device is slightly different from a pre-intended reference pattern, such as a pattern obtained from design values, the method is to replace it with the pattern actually obtained from the photoelectric conversion device. If so, it can be applied to all.

〔Effect of the invention〕

(1) A temporary reference pattern is created through predetermined calculations, and then a true reference pattern is automatically created based on this temporary reference pattern, so the required reference pattern can be created in an extremely short time. And it can be manufactured accurately.

(2) Since the reference pattern is accurate, image recognition can be performed appropriately.

(3) Since the reference pattern can be easily created, it is easy to update it, and the reference pattern that always matches the pattern obtained from the photoelectric conversion device is created.
Mistakes in image recognition can be prevented.

[Brief explanation of the drawing]

FIGS. 1(A) to 1(d) are 8 explanatory diagrams of the reference pattern manufacturing method according to the present invention, in which (A) is a diagram of a temporary reference pattern, and (B) is an image of a target member obtained from a photoelectric conversion device. , (C) is a diagram of a true reference pattern, FIG. 2 is a diagram of an image recognition device, and FIG. 3 is a diagram showing the configuration of an image recognition circuit of the image recognition device.

Claims (1)

[Claims] A method for creating a temporary reference pattern by calculation based on the design dimensions of the object and the designed optical magnification of the photoelectric conversion device; A method for identifying the temporary reference pattern and the target pattern and recognizing the position of the target pattern by calculating the correlation with the reference pattern; 1. A method for creating a reference pattern in image recognition, comprising the steps of: creating a pattern and registering the pattern.