JPH05307608A - Image processing method and image processor - Google Patents

Abstract

PURPOSE:To remove noises from an image including the noises and to rapidly and highly precisely detect the centroid coordinate position of a specific mark. CONSTITUTION:An image and a blur image are picked up by using an image pickup device and a blur image pickup device. An area having a large difference of luminance values between the image 11 and the blur image is binarized and extracted to obtain an image 12. Thickening processing is applied to the image 12 n times through the 1st logical filter to obtain an image 13 and then thinning processing is applied to the image 13 m times through the 2nd logical filter to obtain an image 14. All noises are removed from the image 14 by said processing. Finally the centroid coordinates of a signal area 25 remaining in the image 14 are detected to end image processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to image processing, and more particularly to a method and apparatus for position detection of concentric circle marks used to indicate a specific position.

[0002]

2. Description of the Related Art Automation of journalizing or monitoring in a physical distribution process is realized by attaching information necessary for automation and extracting information by image processing.

When performing such image processing, it is preferable if the position where the information is written in the captured image can be accurately identified, but if it cannot be identified, a specific mark is added to this information. By marking and detecting this mark in the image, the position where the information is written is known. This detection is
This is performed by overlapping a specific mark and a pattern of the specific mark with a specific mark printed at a position where information is written in a captured image.

As described above, in order to detect a specific mark, for example, a concentric circle mark, in the picked-up image, the superimposing method described below is performed. FIG. 9 is a conceptual diagram showing a captured image. In the image 1, the concentric circle mark 2 and the noises 3, 3, ... Are mixed, and the barycentric coordinate position of the concentric circle mark 2 is detected from among these. FIG. 10 is a conceptual diagram showing a method of detecting the barycentric position of the mark. is there. The reference concentric circle pattern 4 having the same size as the concentric circle mark 2 is superimposed on the entire surface of the image 1 as indicated by the arrow, thereby detecting the barycentric coordinate position of the concentric circle mark. The position of the necessary information in the image can be found from this center coordinate position.

[0005]

However, when the mark 2 is detected from the image 1 in which a large number of noises 3, 3, ... Of various patterns are mixed as shown in FIG. The probability of false detection of a similar shape increases. To reduce the probability of false detection,
It is possible to make the mark 2 difficult to appear in general. For example, the mark 2 may be complicated or the mark 2 may be enlarged.

However, in the former method of making the mark 2 complicated, when the required information is rotated at an arbitrary angle on the captured image 1, the mark 2 is also rotated at various rotation angles. Since they are overlapped with each other, it takes a long time to detect them. Further, the latter method of enlarging the mark 2 has a problem that it takes a long time to judge whether or not the superimposed marks are the same because the mark is large.

The present invention has been made in view of the above circumstances, and removes noise from an image in which noise is mixed,
An object of the present invention is to provide an image processing method and an image processing device for detecting the barycentric coordinate position of a concentric circle mark at high speed and with high accuracy.

[0008]

According to a first aspect of the present invention, there is provided an image processing method for detecting a barycentric coordinate position of a concentric circle mark in an image, wherein the image is taken to obtain a first image, A process of obtaining a second image by providing the image with a blur amount determined by the line width of the concentric circle marks and the distance between the lines, and binarizing the difference image between the first image and the second image. To obtain a binarized image, the binarized image is subjected to a thickening process once or a plurality of times, and then 1
The method is characterized by including a step of performing the thinning processing once or a plurality of times and a step of detecting the barycentric coordinate position of the image remaining as a result.

An image processing method according to a second aspect of the present invention is an image processing method for detecting the barycentric coordinate position of a concentric circle mark in an image, the process of capturing the image to obtain a first image, and smoothing the image. A process of obtaining a second image having a blur amount depending on the line width and the distance between the concentric circle marks, and a binarized image by binarizing the difference image between the first image and the second image. A step of obtaining, a step of performing a thickening process once or a plurality of times on the binarized image, a step of performing a thinning process once or a plurality of times, and a step of detecting the barycentric coordinate position of the image remaining as a result. And are included.

An image processing apparatus according to a third aspect of the present invention is an image processing apparatus for detecting the barycentric coordinate position of a concentric circle mark in an image, and an image pickup device for picking up the image to obtain a first image; An image pickup device that obtains a second image by providing a blur amount that depends on the line width and the distance between the concentric circle marks, and a difference processor that obtains a difference image between the first image and the second image. , A binarization processor for binarizing the difference image to obtain a binarized image, a first logical filter for thickening the binarized image once or a plurality of times, and the thickening process Then, a second logical filter that performs one or more thinning processes and a detector that detects the barycentric coordinate position of the image remaining as a result are provided.

An image processing apparatus according to a fourth aspect of the present invention is an image processing apparatus for detecting a barycentric coordinate position of a concentric circle mark in an image, and an image pickup device for picking up the image to obtain a first image, and smoothing the image. A spatial filter that obtains a second image having a blur amount depending on the line width and the distance between the concentric circle marks, a difference processor that obtains a difference image between the first image and the second image, and the difference A binarization processor for binarizing the image to obtain a binarized image, a first logical filter for thickening the binarized image once or a plurality of times, and following the thickening process Second to apply thinning process once or multiple times
It is characterized by comprising a logic filter and a detector for detecting the barycentric coordinate position of the image remaining as a result.

[0012]

In the image processing method and image processing apparatus of the present invention,
The difference binarization processing is performed on the image marked with the concentric circle mark and the blurred image of the image. This removes most of the noise. Further, the image obtained by the difference binarization process is subjected to the thickening process once or a plurality of times, and then the thinning process is performed only the number of times when all the noise is removed. In the image obtained as a result, only the black circle centering on the center of gravity of the concentric circle mark remains, and the center of gravity coordinate position is detected by obtaining the center coordinates of the black circle.

[0013]

EXAMPLES The present invention will be specifically described below based on examples thereof. Prior to detailed description, the basic principle of the present invention will be described.

In the present invention, a concentric circle mark is marked on required information and detected. This is because the shape of the concentric circle mark does not change even when the necessary information is rotated at an arbitrary angle on the captured image, and the size of the mark is adjusted by the number of circles. This is because it is possible.

FIG. 1 is an enlarged view of a triple concentric circle mark used in the present invention. Figure 1 (a) shows a concentric circle image that was normally taken.
21 is a blur mark 22 having a blur amount with respect to the concentric circle mark 21. The blur amount of the blur mark 22 is the line width A and the line distance B of the concentric circle mark 21.
Depends on. The concentric circle mark 23 shown in FIG. 1C is extracted by binarizing only the area where the difference in brightness (brightness value) between the concentric circle mark 21 and the blurred mark 22 is large.

Such blurring processing can be obtained by, for example, capturing an image in a state where the lens is out of focus when capturing an image with a television camera, or smoothing the image by image processing. ..

FIG. 2 is an explanatory diagram showing a method for detecting the barycentric coordinate position of a concentric circle mark from a captured image in which concentric circle marks and noise are mixed. FIG. 2A shows an imaged image, which will be referred to as a first image. In the image 11 which is the first image, the concentric circle mark 21 and the noises 31, 31, ... Are mixed. The blurring process described above is applied to the image 11 shown in FIG. 2A to generate a second image. Then, between the second image subjected to the blurring process and the original image 11, only the region having a large difference in brightness (luminance value) is extracted by the binarization process. Figure 2 (b)
Shows the binarized image generated in this way. By this extraction, in the image 12 that is a binarized image, noise 31,
31 ... is greatly reduced, and noise 32, 32 ... is slightly left.

In order to remove the remaining noises 32, 32, ..., the image 12 shown in FIG. 2B is logically subjected to the thickening process of the number of times until the circles forming the concentric circle mark 23 come into contact with each other. Use a filter. FIG. 2C shows an image generated by subjecting the image 12 to a thickening process. In this image 13, the concentric circle marks 24 are black circles, and the noises 33, 33 ... Are bolded. Next, the image 13 shown in FIG. 2 (c) is subjected to the thinning processing by the number of times the noises 33, 33 are erased by using the logical filter. FIG. 2D shows an image generated by subjecting the image 13 to thinning processing. In the image 14 processed in this way, all the noise is removed, and the black circle 25 is displayed at the position of the concentric circle mark 2. The barycentric coordinate position of this black circle 25 is calculated, and the barycentric coordinate position of the concentric circle mark 2 is obtained. And

Next, based on the above basic principle,
The detailed contents of the present invention will be explained based on the drawings showing the first embodiment.

FIG. 3 is a block diagram showing the constituent functions of the image processing apparatus of the present invention. A difference processor 53 and 2 which include an image pickup device 51 for picking up an image including the concentric circle mark 2 to be detected and a blurred image pickup device 52 for picking up a blurred image thereof and which performs a differential process on the analog signal of each picked-up image. A binarization processor 63 for performing a binarization process is provided. This image pickup device 51
FIG. 4 shows a specific example of the blurred image pickup device 52. Figure 4
It is explanatory drawing which shows the optical system which images an image and its blurred image simultaneously. An image is simultaneously transmitted and reflected by using the half mirror 41. These images are captured by the TV camera 42 and the TV camera 43 as an image and a blurred image, respectively. At this time, the blurred image is captured with the above-described blur amount.

The respective images thus captured are shown in FIG.
The difference processing unit 53 shown in FIG. 3 performs difference processing, and the binarization processing unit 63 extracts this as a binary image and digitizes it. This image is stored in the frame memory 60 by any method. Further, in this image processing apparatus, a thickening processor 57, which is a first logical filter, for thickening the stored image, and a thinning processor 58, which is a second logical filter, for performing subsequent thinning processing. And a barycentric coordinate position detector 59 for determining the position of the image. The image stored in the frame memory 60 is thickened by the thickening processor 57 and thinned by the thinning processor 58, and is stored in the frame memory 60 as an image from which noise is removed. Then, the barycentric coordinate position detector 59 detects the barycentric coordinate position of the residual signal area. Also, these devices are controlled by the controller 50, and the detection result is registered.
Stored in 61.

Next, the procedure of implementation by the image processing apparatus thus configured will be described. FIG. 5 is a flow chart for explaining a method of implementing the image processing method described in FIG. In step S01, the image 11 (FIG. 2) is obtained by using the image pickup device 51 and the blurred image pickup device 52 of the optical system shown in FIG.
And capturing a blurred image. Here, the line width A and the inter-line distance B of the triple concentric circle marks 21 marked on the image 11 are set according to the types of noise mixed in the image 11. In step S02, an area having a large difference in luminance value between the image 11 and the blurred image is binarized and extracted to obtain an image 12 (FIG. 2).
In step S03, the image is thickened by the first logical filter n times to obtain the image 13 (FIG. 2), and in step S04, the image is thinned by the second logical filter m times and the image 14 (FIG. 2) is obtained. To get By this processing, all the noise in the image 14 is removed. Finally, in step S05, the image
The barycentric coordinates of the remaining signal area in 14 are detected, and the image processing ends.

Next, the present invention will be described with reference to the drawings showing a second embodiment thereof. FIG. 6 is a block diagram showing the constituent functions of the image processing apparatus of the present invention. An image pickup device 51 for picking up an image including the concentric circle mark 2 to be detected and a blurred image pick-up device 52 for picking up a blurred image thereof are provided, and an analog signal of each picked-up image is converted into a digital signal A /
The D converter 62 is provided. Further, this image processing apparatus includes a difference processor 55 for performing a difference process between a digitized and stored image and a blurred image thereof, and a binarization processor 56 for binarizing the extracted image. A thickening processor 57 that is a first logical filter that performs a thickening process on the value image, and a thinning processor 58 that is a second logical filter that subsequently performs a thinning process.
And the barycentric coordinate position detector 59 for obtaining the position of the remaining image
It has and.

An image and a blurred image thereof are picked up by the optical system shown in FIG. 4, digitized and stored in the frame memory 60 by an arbitrary method. The image stored in the frame memory 60 is the same as that of the first embodiment except that the difference process and the binarization process are performed after being digitized. Omit it. Furthermore, the procedure performed by the image processing apparatus thus configured is the same as that in the first embodiment described above, and a description thereof will be omitted.

Next, the present invention will be described with reference to the drawings showing a third embodiment. FIG. 7 is a block diagram showing the constituent functions of the image processing apparatus of the present invention. An image pickup device 51 for picking up an image including the concentric circle mark 2 to be detected is provided, and an A / D converter 62 for converting an analog signal of the picked-up image into a digital signal is provided. Further, this image processing device generates a blurred image of a digitized and stored image, and a smoothing processor 54 that is a spatial filter, and performs a difference process between the smoothing processor 54 and the blurred image. A processor 55 and a binarization processor 56 that binarizes the extracted image.
And a thickening processor 57 which is a first logical filter for thickening the binary image, a thinning processor 58 which is a second logical filter for thinning the binary image, and a position of the remaining image. The center-of-gravity coordinate position detector 59 is provided.

In the present embodiment, a pseudo blurred image can be generated by smoothing the image using the spatial filter 54 instead of capturing the blurred image by the optical system. This blurred image is subjected to smoothing processing several times so that the binarized and extracted mark becomes the above-mentioned concentric circle mark 23.

With such a device, the image is captured by the image pickup device.
The image is picked up by 51, digitized, and stored in the frame memory 60 by an arbitrary method. A blurred image obtained by smoothing the image by the spatial filter 54 is also stored in the frame memory 60 by an arbitrary method. The device is the same as the second embodiment except that the blurred image is obtained by the spatial filter 54, and the same reference numerals are given to the same devices and the description thereof will be omitted.

Next, the procedure of implementation by the image processing apparatus thus configured will be described. FIG. 8 is a flowchart for explaining a method of implementing the image processing method described in FIG. In step S11, the image 11 (FIG. 2) is captured using the image capturing device 51 of the optical system. Here, the line width A and the inter-line distance B of the triple concentric circle marks 21 marked on the image 11 are set according to the types of noise mixed in the image 11. In step S12, the spatial filter 54 performs blurring processing k times to generate a blurred image. In step S13, the area where the difference in brightness value between the image 11 and the blurred image is large is set to 2
Extract as a value image to obtain image 12 (FIG. 2). In step S14, the thickening process is performed on the image by the first logical filter.
The image 13 (FIG. 2) is obtained by repeating the image processing. In step S14, the image is subjected to the thinning processing m times by the second logical filter to obtain the image 14
(Fig. 2) is obtained. By this processing, all the noise in the image 14 is removed. Finally, in step S15, the barycentric coordinates of the remaining signal area in the image 14 are detected, and the image processing ends.

[0029]

As described above, in the image processing method and the image processing apparatus of the present invention, noise is generated by binarizing the difference image between the image which is the first image and the blurred image which is the second image. Is removed and the barycentric coordinate position of the concentric circle mark is
The present invention has excellent effects such as high-speed and high-precision detection.

[Brief description of drawings]

FIG. 1 is an enlarged view of a triple concentric circle mark used in the present invention.

FIG. 2 is an explanatory diagram showing a method of detecting the barycentric coordinate position of a concentric circle mark according to the present invention.

FIG. 3 is a block diagram showing constituent functions of an image processing apparatus of the present invention.

FIG. 4 is an explanatory diagram showing an optical system for simultaneously capturing an image and a blurred image thereof according to the present invention.

FIG. 5 is a flowchart illustrating an implementation procedure method of the image processing method of the present invention.

FIG. 6 is a block diagram showing constituent functions of the image processing apparatus of the present invention.

FIG. 7 is a block diagram showing constituent functions of the image processing apparatus of the present invention.

FIG. 8 is a flowchart illustrating an implementation procedure method of the image processing method of the present invention.

FIG. 9 is a conceptual diagram showing a captured image including a mark.

FIG. 10 is a conceptual diagram showing a conventional method of detecting the barycentric position of a mark.

[Explanation of symbols]

 11 First image 12 Difference image 21 Concentric circle mark 41 Half mirror 51 Image pickup device 52 Blurred image pickup device 53, 55 Difference processor 55, 63 Binarization processor 54 Spatial filter 57 First logical filter 58 Second logical filter 59 Center of gravity coordinate position detector 60 Frame memory 61 Register A Line width of concentric circle mark B Distance between lines of concentric circle mark

Claims (4)

[Claims] 1. An image processing method for detecting a barycentric coordinate position of a concentric circle mark in an image, the step of capturing the image to obtain a first image, and the line width and the distance between the concentric circle marks in the image. A step of obtaining a second image by providing an image with a more definite blur amount; a step of binarizing the difference image between the first image and the second image to obtain a binarized image; The processed image is thickened one or more times,
Next, an image processing method comprising: a process of performing a thinning process once or a plurality of times; and a process of detecting a barycentric coordinate position of an image that remains as a result. 2. An image processing method for detecting the barycentric coordinate position of a concentric circle mark in an image, the process of capturing the image to obtain a first image, and smoothing the image to obtain a line width and a line of the concentric circle mark. A step of obtaining a second image having a blur amount depending on an inter-distance, a step of binarizing a difference image between the first image and the second image to obtain a binarized image, and the binarization The image is thickened one or more times,
Next, an image processing method comprising: a process of performing a thinning process once or a plurality of times; and a process of detecting a barycentric coordinate position of an image that remains as a result. 3. An image processing apparatus for detecting the barycentric coordinate position of a concentric circle mark in an image, comprising: an image pickup device for picking up the image to obtain a first image; and a line width and a line of the concentric circle mark in the image. An image pickup device that obtains a second image by imaging with a blur amount that depends on the inter-distance, a difference processor that obtains a difference image between the first image and the second image, and the difference image is binarized A binarization processor for obtaining a binarized image by processing, a first logical filter for thickening the binarized image once or a plurality of times, and one or a plurality of times following the thickening process An image processing apparatus comprising: a second logical filter that performs the thinning processing of 1. and a detector that detects the barycentric coordinate position of the image that remains as a result. 4. An image processing apparatus for detecting the barycentric coordinate position of a concentric circle mark in an image, comprising: an image pickup device for picking up the image to obtain a first image; and a line width of the concentric circle mark for smoothing the image. And a spatial filter that obtains a second image having a blur amount that depends on the distance between lines, a difference processor that obtains a difference image between the first image and the second image, and binarize the difference image. A binarization processor that obtains a binarized image, a first logical filter that performs a thickening process on the binarized image once or a plurality of times, and a thinning process that is performed once or a plurality of times after the thickening process. An image processing apparatus, comprising: a second logical filter that applies the above; and a detector that detects the barycentric coordinate position of the image that remains as a result.