JPH05143739A - Image processor - Google Patents

Abstract

PURPOSE:To obtain the image processor for which required memory capacity is reduced. CONSTITUTION:Image data are read by a camera (S1), a matching window is designated to these data (S2), and an internal feature part (projection data, for example,) is extracted (S3). Afterwards, a comparative template is prepared from a model template stored in advance (S4). This model template is constituted as a certain basic shape such as projection data, for example, and the comparative template enabling matching with the feature part of the image data is prepared from the model template. Then, the comparative template is matched with the image data in the window (S5), and the result is preserved (S6). By repeating such a processing (S7), the objective image is recognized from the photographic image of the camera.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus, and more particularly to a target image pattern in the image data by performing a matching process with the pattern data stored in advance for the image data acquired by the image reading means. The present invention relates to an image processing device that recognizes.

[0002]

2. Description of the Related Art Conventionally, in a device such as a chip mounter, positioning of a substrate is performed through image processing of marks on the substrate taken in from a CCD camera or the like.

FIG. 1 shows a structural example in which a printed circuit board 2 conveyed on a conveying path 4 is positioned prior to component mounting. The camera 9 having an image sensor such as a CCD,
The mark 3 serving as a reference for positioning the printed circuit board 2 at a predetermined position is imaged, and the image data thereof is input to the image processing device 18. The image processing device 18 recognizes the position, size, shape, etc. of the mark 3, that is, the printed circuit board 2 based on the pattern matching process of the image data of the camera 9, and controls the drive system of the transport path 4 according to the result. Then, the printed circuit board 2 is positioned.

Further, the monitor 16 can be used to display the image obtained from the camera 9 as it is or display the result of the pattern matching process.

[0005]

Conventionally, the mark 3 having various shapes which makes it easy to recognize the center (or reference) position by the matching process as shown in FIG. 4 has been used. .. These marks 3
Are formed on the printed circuit board 2 (or another member) by etching, printing, or the like.

Conventionally, a data pattern as shown in FIG. 4 is stored in the memory as it is as image data (for example, multivalued digital data) of the same format as the image data acquired by the camera 9, and the data pattern obtained by the camera 9 is obtained. A configuration is adopted in which the obtained image data is compared with each other in the matching process.

Therefore, there is a problem that a large storage area is required for the matching data pattern.

An object of the present invention is to solve the above problems and to provide an image processing apparatus which requires a small storage area for a data pattern for matching.

[0009]

In order to solve the above problems, in the present invention, the image data obtained by the image reading means is subjected to a matching process with the pattern data stored in advance, whereby In an image processing apparatus for recognizing a target image pattern in image data, only characteristic data of pattern data to be compared with the image data is stored in a storage means, and when the matching processing is performed, the characteristic data is converted into the image data. And the pattern data that can be used for matching is adopted.

[0010]

According to the above construction, the storage capacity for the pattern data can be extremely small as compared with the case where the pattern data which can be directly used for the matching with the image data is stored.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 2 shows the structure of the control system of the image processing apparatus adopting the present invention. In FIG. 2, reference numeral 9 is a camera similar to that in FIG. 1, which is composed of a CCD camera and the like.

The output signal of the camera 9 is the image processing device 18
Is input to the A / D converter 10 and is converted into digital image data of a predetermined format. The image data output from the A / D converter 10 is once stored in the image memory 11 and, if necessary (or after predetermined image processing).
It is converted back to analog data via the D / A converter 12 and can be displayed on the monitor 16.

Each unit of the image processing device 18 is controlled by the CPU 13. Connected to the CPU 13 are a ROM 14 storing a program to be described later and a RAM 15 used as a work area of the CPU 13 or the like.

Further, the CPU 13 can control other devices such as a substrate transport system of a chip mounter and a mounter head via an external controller 17 according to the image processing result.

Next, the operation of the above configuration will be described.

Here, as in the case of FIG. 1, the CPU 13 controls the conveyance path 4 through the controller 17 by matching the images of the marks 3 on the printed circuit board 2 obtained by the camera 9 to position the printed circuit board 2. Shall be done.

Pattern data of various marks to be recognized as shown in FIG. 4 is stored in advance in a medium such as the ROM 14, the RAM 15 or an external secondary storage device (not shown).

At this time, however, the pattern data of the mark is not stored by a multi-value digital image of the same format as the output image of the camera 9 as in the conventional case, but only the characteristic thereof is stored.

For example, in the following example, a model template is constructed from projection data of the densities of the graphics forming the template, that is, data consisting of the integration results of the pixel densities on the lines along the predetermined direction of the graphics (detailed later). )But,
In addition, a configuration that stores only the minimum necessary data for specifying the figure, such as the formula for the contour trajectory of the figure that forms the template, density information, shape, and rotation angle, or to specify the figure As a minimum required data format, for example, in the case of a line / point-symmetrical figure, a configuration in which only half of the symmetrical portion is stored as digital data can be considered.

As described above, the template itself is not a template, that is, a template having an output image format of the camera 9 (hereinafter, this is referred to as a comparison template), but only a feature capable of specifying the template. By storing the model of the template (hereinafter referred to as the model template), the storage area for the template can be reduced compared to the conventional case.

The operation of the above configuration will be described in detail below with reference to FIG. FIG. 3 shows the CPU 1 of FIG.
3 shows a control program of No. 3.

In step S1 of FIG. 3, the image of the printed circuit board 2 is captured by the camera 9, and the A / D converter 10 is used.
Is converted into digital data and stored in the image memory 11.

In step S2, as shown in FIG. 5, an area to be subjected to the matching process with respect to the image data in the image memory 11, that is, a matching window w is set. The setting of the matching window w is to roughly detect the position of the mark 3 and the like from a predetermined area on the printed circuit board 2 by searching for density information and specify the matching processing area. So we don't need much precision here.

In step S3, the characteristics of the data in the matching window w are extracted. Here, information such as the density change curve, its inflection point, or the position of these pieces of information in the matching window w is extracted from the image data in the matching window w. here,
Using a comparison template described later, at least a characteristic portion that requires at least a comparison to recognize the target mark 3 is extracted.

In this case, since the comparison template is generated as the projection data as described later, the projection data of the mark 3 is extracted as the characteristic portion. Further, here, since the density correction is required to create the comparison template, the maximum / minimum value of the density information of the mark 3 is extracted.

In the loop of steps S4 to S7, the matching process is performed by comparing the template and the image in the image memory 11.

First, in step S4, the CPU 13, the ROM 14, or the RAM 15 is preliminarily set.
Image memory 1 from the model template prepared in
Play the comparison template to be compared with the image in 1.
That is, a comparison template that can be compared with the feature extraction portion extracted in step S3 from the model template is generated.

FIG. 6 shows an example of a model template to be stored (here, an example of a perfect circle model template). The lower and right waveforms in FIG. 6 form a model template from projective density data which is the integration result of pixel densities on lines along two directions (upper and lower) of a circle. Such data may be stored as data representing the waveform locus shown in the drawing, and storage of such data requires less storage area than storing all pixel data.

The data shown in FIG. 6 is created such that the outside of the mark 3 has a density of 0 and the inside has a uniform maximum density, but in step S4, for example, the image memory 11 is used.
Based on the maximum and minimum densities of the image inside, a comparison template is created by correcting the levels of the bright and dark areas as shown in FIG. Further, when the size of the model template is different from the actual image, the size may be adjusted (reduced in the case of FIG. 7).

In step S5, a matching process for comparing the created comparison template with the characteristic portion of the image data in the matching window of the image memory 11 is performed. In step S5, the result value (for example, correlation value) representing the matching result is stored in the RAM 15 (or 2).
Next storage device).

In step S7, it is determined whether or not the processes of steps S4 to S6 have been performed for all the stored model templates. If step S7 is denied, the address counter and other settings are made in order to perform the above process using the next model template, and then the process returns to step S4.

In step S8, the shape, position, etc. of the mark 3 are recognized from the stored result value, and the image memory 1
Mark 3 in 1 is specified. Then, the result is displayed on the monitor 16, or the controller 17 is used to convey the printed circuit board 2 according to the specific result.
Control.

According to the above embodiment, the comparison template to be directly compared with the photographed image data is not stored as it is, but the model template storing only the characteristic portion is stored. Has an excellent effect that it is possible to save the storage capacity for data transfer and reduce the time required for data transfer.

Considering an 8-bit image per pixel, when a region of 256 × 256 pixels in an 8-bit image memory of 512 × 512 pixels is used as a comparison template, a memory of 64 KB is required for each template. Is. If there are 10 marks for correcting the printed circuit board position and 10 marks for correcting the component mounting position on the printed circuit board 2, 1.28 MB is required as a storage area for the template. . However, in the configuration in which the model template including only the characteristic portion is stored as described above, if projection data is taken in the vertical and horizontal directions as shown in FIG. 6, 20480 bytes will be sufficient under the same conditions.

Although the configuration of the chip mounter is illustrated here, it goes without saying that the present invention is also applicable to image recognition performed for purposes other than component mounting.

[0037]

As is apparent from the above, according to the present invention, the object in the image data can be obtained by performing the matching process on the image data acquired by the image reading means with the pattern data stored in advance. In the image processing device for recognizing the image pattern, only the characteristic data of the pattern data to be compared with the image data is stored in the storage means, and when performing the matching processing, the characteristic data can be used for matching with the image data. Since it employs a configuration that configures various pattern data, the storage capacity for pattern data is extremely small compared to the case of storing pattern data that can be directly used for matching with image data, and data transfer is required. It has an excellent effect that time can be shortened and high-speed image recognition processing can be performed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a basic configuration of a chip mounter.

FIG. 2 is a block diagram of a control system of an image processing apparatus adopting the present invention.

FIG. 3 is a flowchart showing a control procedure of the apparatus of FIG.

FIG. 4 is an explanatory diagram showing a configuration example of marks used in the chip mounter.

5 is an explanatory diagram showing a matching window of the apparatus of FIG.

FIG. 6 is an explanatory diagram showing a model template used for matching in the apparatus of FIG.

FIG. 7 is an explanatory diagram showing a comparison template used for matching of the apparatus of FIG.

[Explanation of symbols]

 2 printed circuit board 3 mark 4 conveyance path 9 camera 10 A / D converter 11 image memory 12 D / A converter 13 CPU 14 ROM 15 RAM 16 monitor

Claims (1)

[Claims] 1. An image processing apparatus for recognizing a target image pattern in the image data by performing a matching process with pattern data stored in advance on the image data acquired by the image reading means, Image processing characterized in that only characteristic data of pattern data to be compared with data is stored in a storage means, and when the matching processing is performed, pattern data usable for matching with the image data is constructed from the characteristic data. apparatus.