WO2018135701A1

WO2018135701A1 - Device and method for correcting position of reference position marker

Info

Publication number: WO2018135701A1
Application number: PCT/KR2017/003752
Authority: WO
Inventors: 김민재; 장수민; 최명진; 김태영
Original assignee: 인스페이스
Priority date: 2017-01-20
Filing date: 2017-04-06
Publication date: 2018-07-26
Also published as: KR20180085981A

Abstract

The present invention relates to a device for correcting the position of a reference position marker. An example of the device for correcting the position of a reference position marker comprises: an image acquisition portion for imaging an object having a reference position marker and generating an acquired image regarding the object; an operation control portion connected to the image acquisition portion, the operation control portion selecting a group of effective preliminary reference position marker candidates, for the reference position marker, from the acquired image applied from the image acquisition portion, the operation control portion selecting a group of final reference position marker candidates, which includes the final reference position marker candidate, from the selected group of effective preliminary reference position marker candidates, the operation control portion comparing information regarding the final reference position marker candidate of the group of final reference position marker candidates with information regarding the reference position marker, thereby determining the final reference position marker, and the operation control portion comparing the current position of the determined final reference position marker and the reference position of the reference position marker and thereby adjusting the current position of the final reference position marker to the reference position; and a storage portion storing information regarding the reference position marker, including values of the distance between two reference position markers and the angle between the two reference position markers.

Description

Apparatus and method for correcting the position of the reference position marker

The present invention relates to an apparatus and method for correcting the position of a reference position marker.

Most image processing systems acquire an image of a target object by using a photographing device such as a camera, and then process the acquired image in a desired manner to determine a correction operation or desired information on the obtained image.

As such, when processing the acquired image, accurate position information of the acquired image is required.

As a method of obtaining position information in the image processing system, various methods are used according to whether the position of the photographing apparatus is changed and whether the position of the target object is changed.

For example, when acquiring an image through aviation or satellite equipment, the object to be photographed is fixed, but the position of the photographing apparatus for acquiring the image changes with time.

As such, when the position of the photographing apparatus changes with time, the position information of the photographing apparatus is required when the image is acquired in order to calculate the position information of the image acquired through the photographing operation of the photographing apparatus.

On the other hand, in the imaging device, such as CCTV or MRI, the position of the imaging device is fixed, but the position of the target object to be photographed is not constant but variable.

As described above, in order to calculate the position information of the target object whose position is not fixed, the photographing operation is performed after adjusting the position of the target object to a known reference position.

For example, when a DNA chip containing thousands to hundreds of thousands of DNA is attached to a glass plate or silicon plate of a predetermined size to acquire an image, a user may position the DNA chip at a reference position. After the adjustment, the DNA chip is photographed.

As such, since the user must manually adjust the position of the DNA chip to the reference position every time the image is taken, it takes a lot of time and money.

In order to reduce such economical waste of cost, a method of calculating a location information of a target object using a reference position marker after photographing a predetermined reference position marker with a predetermined target object has been used.

However, according to the accuracy of the photographed image with respect to the reference position marker, a problem arises in that the reference position marker is not recognized correctly or a wrong position is recognized as the reference position marker.

Accordingly, the technical problem to be achieved by the present invention is to accurately recognize the reference position marker so that accurate image processing on the captured image can be performed.

According to an aspect of the present invention, an apparatus for correcting a position of a reference position marker includes an image acquisition unit configured to photograph an object having a reference position marker to generate a captured image of the object, and is connected to the image acquisition unit. Selecting the effective preliminary reference position marker candidate group for the reference position marker from the photographed image applied from the negative, selecting the final reference position marker candidate group having the final reference position marker candidate from the selected effective preliminary reference position marker candidate group, and The final reference position marker is determined by comparing the information about the final reference position marker candidate of the last reference position marker candidate group with the information about the reference position marker, and comparing the current position of the determined final reference position marker with the reference position of the reference position marker. To adjust the current position of the last reference position marker to the reference position. And a storage unit for storing information about the reference position marker having a value between the reference position marker and a distance between the two reference position markers, wherein the operation control unit is configured in the photographed image. Determining the pixel group made up of a plurality of pixels arranged in a row direction and a column direction seamlessly with gray scale values, and determining the determined pixel group as a plurality of preliminary reference position marker candidates, calculating each preliminary distance, and calculating Comparing the distances associated with each of the preliminary reference position marker candidates with the distances associated with the reference position markers corresponding to the respective preliminary reference position marker candidates, and each of the distances associated with the reference position markers corresponding to the respective preliminary reference position marker candidates; A distance with the same value is present in the relative distance between each of the calculated preliminary reference position marker candidates And, each of the preliminary reference position marker candidates is determined as a valid preliminary reference position marker candidate that is a candidate of the corresponding reference position marker, and determines a valid preliminary reference position marker candidate from a plurality of preliminary reference position marker candidates. The effective preliminary reference position marker candidate group is determined by combining the candidate candidates of the effective preliminary reference position marker candidate, and the operation control unit determines that the plurality of the final reference position marker candidate groups do not exist in the selected effective preliminary reference position marker candidate group. In the preliminary reference position marker candidate, it is determined that there is no candidate of one reference position marker, and using the plurality of preliminary reference position marker candidates, New valid preliminary criteria for determining whether a candidate It provides an operation for determining a marker value candidate.

The operation control unit may determine the final reference position marker candidate group by deleting the effective reserve reference position marker candidate group in which the same effective reserve reference position marker is selected as a candidate of different reference position markers from the selected effective reserve reference position marker candidate group.

The operation control unit may determine a value of the distance between the assumed reference position markers and the angle between the two vectors in the final reference position marker candidates of the final reference position marker candidate group, which is information about the assumed reference position markers for each final reference position marker candidate. May be calculated and the final reference position marker candidate belonging to the final reference position marker candidate group having the same information as the information about the reference position marker may be determined as the final reference position marker.

In the method of correcting the position of the reference position marker, the process of increasing the brightness value of the obtained reference image is performed, the process of increasing the brightness value is performed, and then a Hough transform is performed to detect a circle. Searching for an optimal circle among the detected circles and selecting the pixel group; removing noise existing outside the pixel group based on the detected pixel group; Determining a pixel group consisting of a plurality of pixels arranged seamlessly in a row direction and a column direction, and determining the determined pixel group as a plurality of preliminary reference position marker candidates;

Calculating a distance between each preliminary reference position marker candidate and each remaining preliminary reference position marker candidate to calculate a distance related to each of the preliminary reference position marker candidates; Comparing the distances associated with the reference position markers corresponding to the preliminary reference position marker candidates,

If a distance having a value equal to each of the distances associated with the reference position markers corresponding to each of the preliminary reference position marker candidates exists at a distance related to each of the calculated preliminary reference position marker candidates, the respective preliminary reference position marker candidates correspond to each of the preliminary reference position marker candidates. Determining an effective preliminary reference position marker candidate from the plurality of preliminary reference position marker candidates by determining the effective preliminary reference position marker candidate as a candidate of the reference position marker, and combining the effective preliminary reference position marker candidate that is a candidate of the reference position marker Determining a valid preliminary reference position marker candidate group by selecting a valid preliminary reference position marker candidate group for the reference position marker, and a final reference position marker candidate group having a final reference position marker candidate from the selected effective preliminary reference position marker candidate group Selecting the final reference position marker candidate group; Comparing the information about the species reference position marker candidate with the information about the reference position marker, determining whether there is a final reference position marker candidate group having the same information as the information about the reference position marker, and in the reference position marker If there is a final reference position marker candidate group having the same information as the information about, determining a final reference position marker from the hypothesized reference position marker belonging to the last reference position marker candidate group that exists; Comparing a reference position of a position and a reference position marker to adjust the current position of the final reference position marker to the reference position, if there is no final reference position marker candidate group having the same information as the information on the reference position marker , One of the plurality of preliminary reference position marker candidates Determining that a candidate of the quasi-position marker does not exist, and using the plurality of preliminary reference position marker candidates, to determine whether the candidate of the remaining reference position marker except for one reference position marker that is assumed to not exist is present. And determining the new valid preliminary reference position marker candidate.

The selecting of the final reference position marker candidate group includes deleting the effective reference reference position marker candidate group in which the same effective preliminary reference position marker is selected as a candidate of different reference position markers from the selected effective preliminary reference position marker candidate group. The candidate group can be determined.

The determining of the last reference position marker may include: a distance between the assumed reference position markers, which is information about an assumed reference position marker for each final reference position marker candidate, in the last reference position marker candidate of the last reference position marker candidate group; Calculating a value of an angle between two vectors, comparing whether information about a reference position marker and information about the calculated assumed reference position marker are the same, and calculating the information about the reference position marker and the calculated reference position And determining a final reference position marker candidate belonging to the final reference position marker candidate group as the final reference position marker when there is a final reference position marker candidate group having the same information on the position marker.

Comparing whether the information about the reference position marker and the calculated assumed reference position marker are the same, obtaining a center line between the markers, finding the center line, and then using the reference point vector and the starting point of the optimal center line, the angle between the two markers. The method may further include: rotating the image by the obtained angle.

According to this aspect, the position marker corresponding to the reference position marker in the captured image is determined, and the position of the determined reference position marker is moved to the reference position of the reference position marker.

Therefore, since the position adjustment operation to the reference position which is manually performed is automatically performed, cost and time are saved.

Also, even though the number of the determined reference position markers does not match the number of the reference position markers and a part of the determined reference position markers is not detected, the final reference corresponding to the corresponding reference position marker using the remaining final reference position marker candidates. Detect location markers. This improves the accuracy of the position detection operation of the reference position marker.

1 is a schematic block diagram of an apparatus for correcting a position of a reference position marker according to an embodiment of the present invention.

2 is a flowchart illustrating an operation of an apparatus for correcting a position of a reference position marker according to an exemplary embodiment of the present invention.

FIG. 3 is a flowchart illustrating a method of calculating information about an existing position marker in FIG. 2.

FIG. 4 is a flowchart illustrating a method of generating a valid preliminary reference position marker candidate group in FIG. 2.

FIG. 5 is a diagram illustrating a position of a reference position marker used in a position correcting apparatus of a reference position marker according to an embodiment of the present invention.

FIG. 6 is a diagram illustrating a vector formed by the reference position marker shown in FIG. 5.

7 (a) and 7 (b) show values of angles formed by two vectors, respectively.

8 is a diagram illustrating an example of a captured image of an inspection train according to an exemplary embodiment of the present invention.

9 is a view showing an example of a vector formed by the final reference position marker candidate group in an embodiment of the present invention, (a) is a view showing a vector formed in the first final reference position marker candidate group, 2 is a diagram illustrating a vector formed in the final reference position marker candidate group.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

When a component is referred to as being "connected" or "connected" to another component, it is to be understood that the component may be directly connected or connected to the other component, but there may be other components in between. do. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Next, a reference position marker position correction apparatus and method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, a reference position marker position correction device according to an embodiment of the present invention will be described in detail with reference to FIG. 1.

An apparatus for correcting a position of a reference position marker according to an exemplary embodiment of the present invention shown in FIG. 1 includes an image acquisition unit 10, an operation control unit 20 connected to the image acquisition unit 10, and a storage connection connected to the operation control unit 20. The unit 30 and the display unit 40 connected to the operation control unit 20 are provided.

The image acquisition unit 10 includes a camera such as a charge coupled device (CCD) camera and the like, and photographs an object having a predetermined reference position marker to generate a corresponding image, and then generates an image. )

The operation control unit 20 includes a controller 21 connected to the image acquisition unit 10 and a storage unit 22 connected to the controller 21.

The controller 21 is referred to as a candidate group of preliminary reference position markers for the reference position markers in the captured image input from the image acquisition unit 10 (hereinafter, referred to as 'photographed images') (hereinafter, referred to as 'preliminary reference position marker candidate groups'). Selects a final reference position marker candidate group having a final reference position marker candidate from the selected preliminary reference position marker candidate group, the information about the final reference position marker candidate and the reference position marker of the final reference position marker candidate group Compares the information about to determine a final reference position marker, determines a final reference position marker corresponding to the reference position marker, and determines the current position of the determined final reference position marker and the position of the reference position marker (hereinafter referred to as' reference position marker). Image position is adjusted to the reference position by adjusting the current position of the final reference position marker to the reference position.

By the operation of the controller 21 of the operation control unit 20, the position of the reference position marker is not manually positioned to the reference position before photographing the object.

The storage unit 22 is for storing data generated during the control operation of the controller 21.

The storage unit 30 stores information about each reference position marker, that is, a distance between two reference position markers calculated using two vectors of two reference position markers, and an angle formed by the two reference position markers (ie, The magnitude of the angle between the two vectors) and the direction of each reference position marker (that is, the sign of the magnitude of the angle).

In this example, the storage unit 22 stores data generated during the control operation of the controller 21 and the storage unit 30 storing information on the position of the reference position marker, respectively, but one storage unit is provided. Only the

part

22 or 30 can be used.

The display unit 40 is connected to the control unit 21 of the operation control unit 20 and may be formed of a liquid crystal display (LCD) or an organic light emitting display (OLED).

The corresponding image according to the control operation of the controller 21 of the display unit 40 is output so that the user can visually check the position adjustment process for the captured image.

Next, with reference to FIG. 2, the control operation | movement with respect to the position correction apparatus of the reference position marker which has such a structure is demonstrated.

In this example, the image taken by the image acquisition unit 10 is an image for confirming the reaction result after applying the reaction material to the test sample, such as blood or DNA, to the image acquisition unit 10 according to the reaction The color (i.e., gradation value) of the captured image is changed, and the reference position marker is already positioned at a predetermined position of the test tray containing these test samples.

However, the present invention is applicable not only to test samples such as blood and DNA, but also to other objects on which test trays or reference position markers are located for determining whether or not a semiconductor device or electronic component is defective or the like. ) Is applied to all devices that adjust the position of the captured image taken by the reference position to the reference position using the reference position marker.

When the power necessary for the operation is supplied and the operation of the position correcting apparatus of the reference position marker is started, the controller 21 of the operation control unit 20 starts the operation (S10).

The controller 21 in which the operation is started calculates and stores information on the reference position markers P1-Pn (n = 1, 2, 3, 4, ...) in the storage unit 30 (S20), and the image acquisition unit. An operation of discriminating the preliminary reference position marker candidate groups C1-Cm (m = 1, 2, 3, 4, ...) for the reference position markers P1-Pn is performed from the captured image photographed by (10). (S30).

Next, the controller 21 determines the final reference position marker corresponding to the reference position markers P1-Pn among the determined preliminary reference position marker candidate groups C1-Cm (S40), and the reference position markers P1-Pn. An operation of correcting the position of the final reference position marker to the reference position by rearranging the position of the photographed image by using the reference position and the position of the final reference position marker (S50).

First, referring to FIG. 3, an operation of the controller 21 that calculates information about the reference position markers P1-Pn and stores the information in the storage unit 30 will be described.

The operation of calculating and storing the information about the reference position markers P1-Pn may change at least one of the position and the number of the reference position markers P1-Pn to change the information of the reference position markers P1-Pn. Is carried out every time.

As shown in FIG. 5, the test tray T11 is provided with a plurality of grooves H11 and H12 in which a desired test sample is contained, and the grooves H11 function as reference position markers P1-Pn. The other groove H12 is a groove containing a test sample.

In the case of Fig. 5, the number of reference position markers P1-P4 (n = 4) is four, but the number and positions of these reference position markers P1-P4 are changed as necessary.

The groove H11 serving as the reference position markers P1-P4 is expressed in the same color (eg, white) as when the corresponding test feed reacts according to the test result when the image is acquired by the image acquisition unit 10. When the position markers P1-P4 are in a normal state, portions corresponding to the reference position markers P1-P4 in the image captured by the image acquisition unit 10 have a predetermined color (eg, white).

In this embodiment, as an example, the case where the reference position markers P1-P4 are located at the corresponding positions of the inspection tray T11 as shown in FIG. 5 will be described as an example.

First, the controller 21 of the operation control unit 20 uses the image acquisition unit 10 to inspect the test tray T11 in which only the reference position markers P1-P4 located in the corresponding grooves H11 are expressed in the set color. By photographing (refer to FIG. 5), only the reference position markers P1-P4 acquire a reference image having a set color (that is, a set gray scale value) (S21).

A process of increasing the brightness value of the obtained reference image is performed. By performing such a process, the feature points of the marker and the pixel group are better represented, and high accuracy can be obtained in the pixel group search and marker detection to be performed later.

After the process of increasing the brightness value is performed, a Hough transform is performed to detect a circle. The optimal circle among the detected circles is searched and selected as the pixel group.

By performing such a process, since there is a lot of noise outside the pixel group and the marker detection rate is significantly lowered when the marker is detected, the error can be eliminated in advance.

A process of removing noise existing outside the pixel group based on the searched pixel group is performed (S00).

Then, in the reference image having a plurality of pixels, pixels having a set gray level value (for example, 255) are determined for each pixel group consisting of pixels arranged in a row direction and a column direction without interruption. It is determined that each reference position marker P1-P4 is located at a portion where each pixel group is located, and the image of the reference position markers P1-P4 is determined from the reference image to determine the reference position marker P1-P4. (S22).

Next, the center position of the corresponding pixel group with respect to each of the determined reference position markers P1-P4 (that is, the position (x _n ) of the pixel located among the pixels arranged in the row direction) and the center of the pixels arranged in the column direction. Position (y _n ) of the located pixel] is calculated, and the calculated position (x _n , y _n ) is determined as a position with respect to each reference position marker (P1-P4) and stored in the storage unit 22 (S23). .

As such, when the position for each reference position marker P-P4 is determined, the controller 21 defines a vector generated by the reference position markers P1-P4 (S24), and then uses the defined vectors to define two references. The distance between the position markers P1-P4 and the angle formed by two different vectors are calculated and stored in the storage unit 30 as information on each reference position marker P1-Pn (S25).

As shown in FIG. 6, the vector formed based on the first reference position marker P1 is a vector V (P1-P2) formed by the first reference position marker P1 and the second reference position marker P2. )), The vector V (P1-P3) formed by the first reference position marker P1 and the third reference position marker P3, and the first reference position marker P1 and the fourth reference position marker P4. Is a vector (V (P1-P4)) formed by.

The vector formed based on the second reference position marker P2 is a vector V (P2-P1) formed by the second reference position marker P2 and the first reference position marker P1, and the second reference position. The vector V formed by the marker P2 and the third reference position marker P3, and the vector V formed by the second reference position marker P2 and the fourth reference position marker P4. P2-P4)).

Further, the vector formed based on the third reference position marker P3 is a vector V (P3-P1) formed by the third reference position marker P3 and the first reference position marker P1, and the third. A vector formed by the reference position marker P3 and the second reference position marker P2 (V (P3-P2)) and a vector formed by the third reference position marker P2 and the fourth reference position marker P4 ( V (P3-P4)).

The vector formed based on the fourth reference position marker P4 is a vector V (P4-P1) formed by the fourth reference position marker P4 and the first reference position marker P1, and the fourth reference position. A vector V formed by the marker P4 and the second reference position marker P2 and a vector V formed by the fourth reference position marker P4 and the third reference position marker P3. P4-P3)).

At this time, two vectors (eg, V (P1-P2) and V (P2-P1)) having opposite directions to each other are regarded as the same vector and define only one vector (eg, V (P1-P2)).

Therefore, when four reference position markers P1-P4 as shown in FIG. 6 are determined, the vectors for the two reference position markers defined by the operation of the controller 21 are V (P1-P2) = V1, V ( P1-P3) = V2, V (P1-P4) = V3, V (P2-P3) = V4, V (P2-P4) = V5 and V (P3-P4) = V6.

As such, when the vectors for the reference position markers P1-P4 are defined, the control unit 22 controls each vector V (P1-P2), V (P1-P3), and V (P1-P1) as shown in [Table 1]. P4), the distance between the corresponding two reference position markers at V (P2-P3), V (P2-P4), V (P3-P4) (ie, the absolute value of the distance between the center positions of the two reference position markers) (| P1-P2 |, | P1-P3 |, | P1-P4 |, | P2-P3 |, | P2-P4 |, | P3-P4 |) are calculated and stored in the storage unit 30 ( S25).

Table 1

Types of two reference position markers forming a vector	Skirter vector	Skirtkergan distance
1-P2	P1-P2) = V1	1-P2 \|
1-P3	P1-P3) = V2	1-P3 \|
1-P4	P1-P4) = V3	1-P4 \|
2-P3	P2-P3) = V4	2-P3 \|
2-P4	P2-P4) = V5	2-P4 \|
3-P4	P3-P4) = V6	2-P4 \|

Next, the controller 21 uses vectors [V (P1-P2), V (P1-P3), V (P1-P4), V (P2-P3), and V ( P2-P4) and V (P3-P4)], the angle θ formed between the two vectors and the direction (clockwise or counterclockwise) of the vector are calculated.

Equation 1

Where θ is the angle between the line vector and the post vector when another vector is formed based on the vector (hereinafter referred to as the 'line vector'), and x _q and y _q is a component of the line vector, respectively, the position in the row direction and the column direction relative to the two reference position markers forming the line vector, that is, the reference position marker corresponding to the end point at the start and end points of the line vector, x _r and y _r is the position of the row direction and the column direction with respect to the reference position marker corresponding to the end point forming the after vector as the components of the after vector, respectively, the V _{line vector is a} hidden line vector, and the V _{after vector is a} posterior vector.)

In Equation 1, when the viewpoint of the line vector and the post vector is not the same, the position of the post vector is moved in the horizontal or vertical direction based on the position of the line vector to match the viewpoint of the line vector and the post vector. Calculate the components of the back line vector and the back vector (x _q , y _q , x _r , y _r ).

Therefore, using Equation 1, an angle θ formed by two different vectors (that is, a line vector and a post vector) is calculated. In this case, the angle of two vectors (for example, the angle between V (P1-P2) and V (P1-P3) and the angle between V (P1-P2) and V (P2-P3)) located in the same row or column. θ) becomes '0 °'.

The calculated angle θ has a positive value or a negative value, and if it is a positive value, the direction indicated by the back vector becomes a counterclockwise direction based on the line vector. If the angle θ is a negative value, the direction indicated by the vector after the line vector becomes clockwise.

For example, as illustrated in FIG. 7A, the value of the angle θ between the vectors V (P1-P2) and the vectors V (P1-P3) becomes' 0 °. In the case of FIG. 7B, the value of the angle θ between the vector V (P1-P2) and the vector V (P2-P4) becomes' −60 °, wherein the calculated angle θ Since the value of is a negative value, the direction indicated by the vector V (P2-P4) (e.g., the vector afterward) based on the vector V (P1-P2) (line vector) becomes clockwise.

In this way, the values of the angles between the vectors calculated from all the vectors V1, V2, V2, V4, V5, and V6 are calculated as shown in [Table 2] and stored in the storage unit 30 (S26).

TABLE 2

Type of two vectors forming an angle θ	The value of the released angle (θ)
V1-V2	PA1
V1-V3	PA2
V1-V4	PA3
V1-V5	PA4
V1-V6	PA5
V2-V3	PA6
V2-V4	PA7
V2-V5	PA8
V2-V6	PA9
V3-V4	PA10
V3-V5	PA11
V3-V6	PA12
V4-V5	PA13
V4-V6	PA14
V5-V6	PA15

By the operation of the controller 21 of the operation control unit 20, the value of the angle between the two reference position markers, which is information on the reference position markers P1-P4, and the vector formed by the reference position marker, When the size and the direction of the vector) are calculated and stored in the storage unit 30, the controller 21 captures a corresponding test tray T12 to be examined and captures a captured image that is an image of the test tray T12. After the acquisition, the operation of correcting the position of the acquired captured image to the reference position is performed.

To this end, the controller 21 of the operation control unit 20 first selects a valid reserve reference position marker from the preliminary reference position markers, and generates an effective reserve reference position marker candidate group using the selected effective reserve reference position markers. It is carried out (S30).

When the operation state of the operation control unit 20 passes to an operation routine for selecting an effective preliminary reference position marker candidate group, as shown in FIG. 4, the controller 21 of the operation control unit 20 firstly obtains an image acquisition unit. The operation 10 is performed to photograph the test tray T12 to acquire a captured image of the test tray T12 (S31).

In the present example, an example of the captured image of the test tray T12 acquired by the image acquisition unit 10 is as shown in FIG. 8, in which the portion expressing the same color as the reference position markers P1-P4 is S1. To the same as S9.

Next, the controller 21 determines a preliminary reference position marker candidate using a pixel having the same gray value as the image of the reference position markers P1-P4 in the obtained captured image (S32). That is, the preliminary reference position marker candidate includes at least one of the reference position markers.

To this end, as described above, the controller 21 uses the grayscale values of the plurality of pixels constituting the photographed image to sequentially rotate pixels having a grayscale value representing a corresponding color (eg, white) in a row direction and a column direction. Each group of pixels consisting of pixels arranged as follows is determined to determine a candidate of the preliminary reference position marker, that is, the preliminary reference position marker candidates S1-Sp (p = 1, 2, 3, ...).

At this time, the number of pixels arranged in succession in each row direction and column direction is added or subtracted by a predetermined number based on the number of adjacent pixels in the row direction and the column direction of the pixel group corresponding to the reference position marker. The margin of determination of the position marker can be varied.

That is, the controller 21 determines that the preliminary reference position marker candidates S1-Sp are located at the portion where each pixel group is located, and the center of the pixels among the pixels arranged in the row direction which is the center position of each corresponding pixel group is determined. The position ys _p of the pixel located among the pixels arranged in the position xs _p and the column direction is calculated and stored in the storage unit 22 as the position of each preset preliminary reference position marker candidate S1-Sp ( S32).

For this reason, the number of the preliminary reference position marker candidates S1-Sp detected in the drawing shown in FIG. 8 is nine (p = 9) in total, and the first to ninth preliminary reference positions for the captured image of FIG. It becomes the marker candidates S1-S9.

Next, the controller 21 performs an operation of determining an effective preliminary reference position marker candidate in which each preliminary reference position marker candidate S1-S9 becomes a candidate of any reference position marker among the reference position markers P1-P4 ( S33).

Thus, the controller 21 first determines the distance between each one of the first preliminary reference position marker candidates S1 and the remaining preliminary reference position marker candidates S2-S9 (ie, the distance related to the first preliminary reference position marker candidate). Is calculated and stored in the storage unit 22.

At this time, the distance calculation operation is the position of the first preliminary reference position marker candidate S1 different from the position of the other preliminary reference position marker candidate S1 as described with reference to step S25 of FIG. 3. The distance between them is calculated to calculate the distance related to the first preliminary reference position marker candidate S1.

The controller 21 checks whether the first preliminary reference position marker candidate S1 is a candidate of the first reference position marker P1 and the calculated first preliminary reference position marker candidate S1 and the remaining preliminary reference positions. The distances (| S1-S2 |, | S1-S3 |, | S1-S4 |, | S1-S5 |, | relevant to the first preliminary reference position marker candidate (S1), which are the distances between the marker candidates (S2-S9). S1-S6 |, | S1-S7 |, | S1-S8 |, | S1-S9 |) and the distances associated with the first reference position marker P1 (| P1-P2 |, | P1-P3 |, | P1 -P4 |), and the distances (| S1-S2 |, | S1-S3 |, | S1-S4 |, | S1-S5 |, | S1 related to the calculated first preliminary reference position marker candidate S1) are compared. -S6 |, | S1-S7 |, | S1-S8 |, | S1-S9 |, the distances associated with the first reference position marker P1 (| P1-P2 |, | P1-P3 |, | P1- It is determined whether there are four or more distances having the same value as each of P4 |).

Thus, the calculated distances (| S1-S2 |, | S1-S3 |, | S1-S4 |, | S1-S5 |, | S1-S6 |, | S1-S7 |, | S1-S8 |, | S1 -S9 |), if there are four or more distances having the same value as each of the distances (| P1-P2 |, | P1-P3 |, | P1-P4 |) associated with the first reference position marker P1, the controller 21 selects the first preliminary reference position marker candidate S1 as an effective preliminary reference position marker candidate that is a candidate of the first reference position marker P1.

At this time, the distances (| P1-P2 |, | P1-P3 |, | P1-P4 |) associated with the first reference position marker P1 are stored as information of each of the reference position markers P1-P4 as described above. It is stored at 30.

In the same way, in order to check again whether the first preliminary reference position marker candidate S1 is a candidate of the second reference position marker P2, the controller 21 checks with the calculated first preliminary reference position marker candidate S1. The distance (| S1-S2 |, | S1-S3 |, | S1-S4 |, related to the first preliminary reference position marker candidate S1, which is the distance between each one of the remaining preliminary reference position marker candidates S2-S9), | S1-S5 |, | S1-S6 |, | S1-S7 |, | S1-S8 |, | S1-S9 |, the distance associated with the second reference position marker P2 (| P1-P2 |, | P2-P3 |, | P2-P4 |) are compared to see if the same distance exists.

The distance (| S1-S2 |, | S1-S3 |, | S1-S4 |, | S1-S5 |, | S1-S6 |, | S1-S7 related to the calculated first preliminary reference position marker candidate S1) |, | S1-S8 |, | S1-S9 |, the same value as each of the distances (| P1-P2 |, | P2-P3 |, | P2-P4 |) associated with the second reference position marker P2. If there is a distance, the controller 21 determines the first preliminary reference position marker candidate S1 as the candidate of the second reference position marker P2. In this case, the first preliminary reference position marker candidate S1 is an effective preliminary reference position marker candidate that is simultaneously the first and second reference position markers P1 and P2 candidates.

Thus, in this manner, it is determined whether the first preliminary reference position marker candidate S1 is a candidate for each of the first to fourth reference position markers P1-P4.

In the same manner, the second preliminary reference position marker candidate S2 to determine which of the first to fourth reference position markers P1-P4 is the candidate of the reference position marker candidate S2. ) And the distance (| S2-S3 |, | S3-S4 |, | S2-S5) related to the second preliminary reference position marker candidate S2, which is a distance between the remaining preliminary reference position marker candidates S1 and S3-S9. |, | S2-S6 |, | S2-S7 |, | S2-S8 |, | S2-S9 |) are calculated. At this time, the distance between the second preliminary reference position marker candidate S2 and the first preliminary reference position marker candidate S1 | S2-S1 | is already the first preliminary reference position marker candidate S1 (| S1). -S2 |), so it is omitted.

Then, the distances (| S2-S3 |, | S3-S4 |, | S2-S5 |, | S2-S6 |, | S2-S7 |, | regarding the calculated second preliminary reference position marker candidate S2) | S2-S8 |, | S2-S9 |) and the distances (| P1-P2 |, | P1-P3 |, | P1-P4 |, | P2 related to each of the first to fourth reference position markers P1-P4). -P3 |, | P2-P4 |, and | P3-P4 |), respectively, so that the second preliminary reference position marker candidate S2 is any one of the first to second reference position markers P1-P4. It is determined whether or not is a candidate.

This operation is applied to each of the remaining preliminary reference position markers S3-S9 to determine which reference position markers P1-P4 are candidates for the preliminary reference position markers P1-P4. From P9), an effective preliminary reference position marker which is a candidate of at least one reference position marker P1-P4 is determined.

Therefore, when the first to ninth preliminary reference position marker candidates S1-S9 are determined as the preliminary reference position marker candidates as shown in FIG. 8, the effective preliminary reference position marker candidates are S1, S2, S3, S4, S7, and S9. Becomes

In this case, the first valid preliminary reference position marker candidate S1 is a candidate of the first reference position marker P1, and the second and fourth valid preliminary reference position marker candidates S2 and S4 are the second reference position marker P2. ) And the third and seventh valid preliminary reference position marker candidates S3 and S7 are candidates of the third reference position marker P3 and the ninth valid preliminary reference position marker candidate S9 is the fourth reference position marker. It is a candidate of (P4).

Next, the controller 21 generates all possible combinations using the corresponding valid preliminary reference position marker candidates S1, S2, S3, S4, S7, and S9 determined as candidates of the respective reference position markers P1-P4. An effective preliminary reference position marker candidate group C1-Cm is generated (S34).

In the case of this example, there are four valid preliminary reference position marker candidate groups C1-Cm (C1-C4), as shown in Table 3 below.

TABLE 3

	P1	P2	P3	P4
C1	S1	S2	S3	S9
C2	S1	S2	S7	S9
C3	S1	S4	S3	S9
C4	S1	S4	S7	S9

Next, the controller 21 selects the final reference position marker candidate group by deleting the candidate group that is not practically possible from the calculated plurality of valid preliminary reference position marker candidate groups C1-C4 (S35). In this case, the effective preliminary reference position marker candidate included in the final reference position marker candidate group becomes the final reference position marker candidate.

That is, in the same effective preliminary reference position marker candidate group C1-C4, the same effective preliminary reference position marker candidate cannot be a candidate of different reference position markers P1-P4. Therefore, the controller 21 removes the same valid preliminary reference position marker candidate among the valid preliminary reference position marker candidate groups C1-C4 when there are candidates of different reference position markers.

The final reference position marker candidates belonging to the last reference position marker candidate group C1 are S1, S2, S3, and S9, wherein the final reference position marker candidate S1 is a candidate of the first reference position marker P1, and the final reference The position marker candidate S2 is a candidate of the second reference position marker P2, the final reference position marker candidate S3 is a candidate of the third reference position marker P3, and the final reference position marker candidate S9 is the first candidate. It is a candidate of the 4 reference position markers P4.

Then, the controller 21 uses each of the last reference position marker candidate groups C1-C4 selected from each of the last reference position markers in the same manner as the method of calculating the information on the respective reference position markers P1-P4. Assume that the candidate is the corresponding reference position marker, and the distance between the hypothesized reference position marker, which is information about each final reference position marker (hereinafter, referred to as the 'preferred reference position marker'), assumed as the corresponding reference position marker, The value of the angle between the vectors (that is, the magnitude of the angle and the vector direction) is calculated (S36).

Then, the controller 21 compares whether the information about the assumed reference position marker and the information about the reference position marker are the same (S37), and thus the final reference position marker candidate group having the same information as the information about the reference position marker. It is determined whether there exists (S38).

If there is a final reference position marker candidate group having the same information as the reference position marker information, the controller 21 determines the assumed reference position marker belonging to the final reference position marker group as the final reference position marker (S39). . That is, each of the hypothesized reference position markers belonging to the final reference position marker candidate group is a reference position marker positioned at the current position instead of the reference position which is the initial position of the reference position marker.

In Table 3, for example, the candidate group C1-C4 selected as the final reference position marker candidate group will be described in more detail.

First, the assumed reference position markers S1, S2, S3, and S9 belonging to the final reference position marker candidate group C1 are respectively referred to the reference position markers P1, P2, P3, and P4. Assuming that the distance between the two assumed reference position markers and the two assumed reference position markers calculated using two vectors for the two assumed reference position markers is calculated, the following [Table 4] and [Table 5]. In the case of the first final reference position marker candidate group C1, the vector formed becomes (a) of FIG. 9.

Table 4

Types of two assumed reference position markers forming a vector	Distance between assumed base position markers	Equal	Distance between anchor point markers
S1-S2	\| S1-S2 \|	same	\| P1-P2 \|
S1-S3	\| S1-S3 \|	same	\| P1-P3 \|
S1-S9	\| S1-S9 \|	same	\| P1-P4 \|
S2-S3	\| S2-S3 \|	same	\| P2-P3 \|
S2-S9	\| S2-S9 \|	same	\| P2-P4 \|
S3-S9	\| S3-S9 \|	same	\| P3-P9 \|

Table 5

Value of angle (θ) between hypothesized reference position markers	Equal	Value of angle (θ) between reference position markers
SA1	same	PA1
SA2	same	PA2
SA3	same	PA3
SA4	same	PA4
SA5	same	PA5
SA6	same	PA6
SA7	same	PA7
SA8	same	PA8
SA9	same	PA9
SA10	same	PA10
SA11	same	PA11
SA12	same	PA12
SA13	same	PA13
SA14	same	PA14
SA15	same	PA15

In the case of the final reference position marker candidate group C1, the value of the distance between the two assumed reference position markers and the angle between the two assumed reference position markers is equal to the values of the reference position markers, respectively.

Accordingly, the hypothesized reference position markers S1, S2, S3, and S9 belonging to the final reference position marker candidate group C1 are each finally referred to as final reference position markers P1, P2, P3, and P4, that is, reference position markers P1. -P4) but becomes a reference position marker located at the current position instead of the reference position which is the initial position of the reference position markers P1-P4.

In the case of the final reference position marker candidate group C2, the assumed reference position markers calculated by assuming the assumed reference position markers S1, S2, S7, and S9 respectively as the reference position markers P1, P2, P3, and P4. Related information is shown in [Table 6] and [Table 7]. In this case, the vector formed in the second final reference position marker candidate group C2 is as shown in FIG. 9B.

Table 6

Types of two assumed reference position markers forming a vector	Distance between assumed base position markers	Equal	Distance between anchor point markers
S1-S2	\| S1-S2 \|	same	\| P1-P2 \|
S1-S7	\| S1-S7 \|	same	\| P1-P3 \|
S1-S9	\| S1-S9 \|	same	\| P1-P4 \|
S2-S7	\| S2-S7 \|	disparity	\| P2-P3 \|
S2-S9	\| S2-S9 \|	same	\| P2-P4 \|
S7-S9	\| S7-S9 \|	same	\| P3-P9 \|

TABLE 7

Value of angle (θ) between hypothesized reference position markers	Equal	Value of angle (θ) between reference position markers
SA1	disparity	PA1
SA2	same	PA2
SA3	disparity	PA3
SA4	same	PA4
SA5	disparity	PA5
SA6	disparity	PA6
SA7	disparity	PA7
SA8	disparity	PA8
SA9	disparity	PA9
SA10	disparity	PA10
SA11	same	PA11
SA12	disparity	PA12
SA13	disparity	PA13
SA14	disparity	PA14
SA15	disparity	PA15

As shown in [Table 6] and [Table 7], since the information about the two assumed reference position markers and the information about the reference position markers are not the same, it is assumed that they belong to the corresponding final reference position marker candidate group C2. Reference position markers S1, S2, S7, S9 are not final reference position markers.

In this way, information about the assumed reference position markers belonging to each final reference position marker candidate group C1-C4 is calculated, until a final reference position marker candidate group having the same information as the information about the reference position markers is retrieved. Perform the comparison operation.

However, when there is no final reference position marker candidate group having the same information as the information about the reference position marker in all the final reference position marker candidate groups C1-C4 (S38), the controller 21 of the operation controller 20 It is determined that the image of the portion corresponding to one of the reference position markers P1-P4 has not been accurately obtained and thus cannot be detected as a candidate reference position marker.

Accordingly, the controller 21 determines that in each final reference position marker candidate group C1-C4, the reference position markers corresponding to the assumed reference position markers are lost one by one (S310), and the process proceeds to step S33. The operation of determining a new valid preliminary reference position marker candidate using the determined preliminary reference position marker candidate is performed.

For example, first, it is assumed that there is no candidate of the first reference position marker P1 among the preliminary reference position marker candidates S1-S9 determined in step S33.

Therefore, the controller 21 reads the distance related to the first preliminary reference position marker candidate S1 stored in the storage unit 22 and the distances (| P2-P3 |, | P2 related to the second reference position marker P2). Compared with -P4 |, it is determined whether the first preliminary reference position marker candidate S1 is a candidate of the second reference position marker P2.

In a similar manner, the controller 21 compares the distance related to the first preliminary reference position marker candidate S1 with the distance related to the third reference position marker P3, so that the first preliminary reference position marker candidate S1 is removed. It is determined whether or not it is a candidate of the third reference position marker P3, and again, the distance related to the first preliminary reference position marker candidate S1 and the distance related to the fourth reference position marker P4 are compared to each other to determine the first preliminary reference position marker candidate. It is determined whether S1 is a candidate of the fourth reference position marker P4.

In this manner, since there are no candidates of the first reference position marker P1 among the plurality of preliminary reference position marker candidates S1 -S9, each expected reference position marker candidate ( The operation of determining whether or not S1-S9 is a candidate of the first reference position marker P1 is omitted.

In this way, the remaining preliminary reference position marker candidates S2-S9 are determined from which of the second to fourth reference position markers P2-P4 are candidates for the reference position markers P2-P4. An effective preliminary reference position marker candidate that is at least one candidate of the reference position markers P2-P4 is calculated.

The controller 21 then combines all of the calculated valid reserve reference position marker candidates to generate a new valid reserve reference position marker candidate group.

At this time, the candidate candidates of the first reference position marker P1 do not exist in each of the generated effective reserved position marker candidate groups C1-Cm (for example, refer to [Table 8]).

Table 8

Effective Reserve Position Marker Candidates	P1	P2	P3	P4
C1	Loss	S2	S3	S9

In this way, a plurality of effective reserve position marker candidate groups C1-Cm in which no candidate of the first reference position marker P1 is present are generated, and as described above, the same effective reserve position marker candidate group C1-Cm is available. It is determined whether there is a valid reserve position marker candidate group C1-Cm in which the reserve position marker candidates are candidates of two or more reference position markers P2-P4 at the same time, and the same effective reserve position marker candidate is simultaneously two or more criteria. When there is a valid preliminary position marker candidate group C1-Cm that is a candidate for the position markers P2-P4, the final reference position marker candidate group is selected by deleting the effective preliminary position marker candidate group.

Next, the same operation as in operation S36 is performed, and information about each assumed reference position marker belonging to each final reference position marker candidate group is calculated, so that the information about the calculated assumed reference position marker and the reference position marker are calculated. When there is a final reference position marker candidate group having the same information (that is, information about the reference position marker from which the information about the first reference position marker is deleted), the assumed reference position marker belonging to the candidate group becomes the final reference position marker.

However, in this process, the final reference position marker having the same calculated information about the reference position marker and the reference position marker (that is, the information about the reference position marker from which the information about the first reference position marker has been deleted) are the same. When there is no candidate group, the controller 21 again determines that there is no candidate of the second reference position marker P2 among the plurality of preliminary reference position marker candidates S1-S9.

Therefore, in the same manner as the operation described above, on the assumption that there is no candidate of the second reference position marker P2 among the plurality of preliminary reference position marker candidates S1-S9, the valid preliminary reference position marker candidate is again judged. A new effective preliminary reference position marker candidate group is generated, and the final reference position marker candidate group is selected from the generated effective preliminary reference position marker candidate groups to determine the final reference position marker.

If the final reference position marker cannot be determined even through this process, the controller 21 determines that there is no candidate of the third reference position marker P3 among the plurality of preliminary reference position marker candidates S1-S9. , Repeat the above operation.

This operation is repeated until the hypothesized reference position marker of the final reference position marker candidate group is finally determined to correspond to the corresponding reference position marker.

Thus, even if the reference position marker is lost in the captured image, the final reference position marker may be selected from among the plurality of assumed reference position markers using other detected assumed reference position markers.

In the case of this example, the case where there is no candidate of one reference position marker P1-P4 among the plurality of preliminary reference position marker candidates S1-Sp is described, but the number of reference position markers lost can be changed. .

As such, when a final reference position marker corresponding to the reference position marker is selected among the plurality of final reference position marker candidates, the controller 21 of the operation control unit 20 determines the current position of the last reference position marker and the reference position of the reference position marker. An operation of repositioning the captured image is performed by using the method (S50).

At this time, the storage unit 22 and the storage unit 30 stores the information on the last reference position marker and the information on the reference position marker, respectively.

Therefore, since the controller 21 can know the positions of the last reference position markers and the reference position markers corresponding to each other by using the stored contents of the

storage units

22 and 30, the controller 21 can determine the final position based on [Equation 2]. The movement amount and the rotation angle are calculated in the row direction and the column direction using the position difference between the reference position marker and the reference position marker, and the position of the photographed image is moved using the calculated movement amount and the rotation angle.

Therefore, by moving the position of the captured image, the position of the final reference position marker is moved to the reference position of the reference position marker, so that the position of the captured image is aligned with the reference position before processing the captured image.

Equation 2

In Equation 2, x _t is a distance between the reference position in the row direction of the corresponding reference position marker and the current position in the row direction of the last reference position marker to be moved corresponding to the reference position, and y _t is the corresponding reference. The distance between the reference position in the column direction of the position marker and the current position in the column direction of the last reference position marker to be moved corresponding to the reference position, x is the final reference position to be moved corresponding to the reference position marker in the captured image. The current position in the row direction of the marker, and y is the current position in the column direction of the last reference position marker to be moved corresponding to the corresponding reference position marker in the captured image.

Further, β is the angle between one of the vectors associated with the last reference position marker and the vector associated with the reference position marker corresponding to the vector. For example, when the last reference position marker is S1, if one of the plurality of vectors related to the last reference position marker is V (S1-S4), the vector of the corresponding reference position marker is V (P1-P4). do.

After the series of processes is completed, a step of precisely correcting once more is performed to accurately correct the positions of the markers.

The calibrating step first finds the centerline between the markers. At this time, the method of calculating the center line between markers uses Equation 3 to obtain the coefficient of and in the linear equation of.

Equation 3

only,

At this time

Is Y ,

Is A ,

Is defined as C. (Ie Y = AC )

Here, in [a, b], a is the coefficient of the straight line x to be obtained, and b is the intercept of y.

x is the current position in the row direction of the last reference position marker to be moved corresponding to the corresponding reference position marker in the captured image, and y is the direction of the column of the final reference position marker to be moved corresponding to the reference position marker in the captured image. Your current location.

To obtain C , it can be expressed as [Equation 4] using Pseudo inverse formula.

Equation 4

Calculate Equation 4, and find the geometric error r to minimize the error of the algebraic error. The formula of the error r is shown in [Equation 5].

Equation 5

The partial differentiation of [Equation 5] is the same as [Equation 6].

Equation 6

The equations [4] to [Equation 6] are calculated to use the a and b values of the C matrix as initial estimates, and the optimal centerline between the markers is obtained by repeating the Gauss-Newton elimination method 10 times in [Equation 6]. Find the straight line equation.

After the optimal center line is obtained, an angle θ of two straight lines is obtained by using a reference line vector and a starting point of the optimal center line.

The equation for obtaining the angle θ is obtained using Equation 7.

Equation 7

After the angle θ is obtained by using Equation 7, the image is rotated by the obtained angle θ.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims

In the position correction device of the reference position marker,

An image acquisition unit for photographing an object having a reference position marker and generating a captured image of the object;

A valid preliminary reference position marker candidate group for the reference position marker in the photographed image applied from the image acquisition unit, connected to the image acquisition unit, and selecting a final reference position marker candidate from the selected effective preliminary reference position marker candidate group Selecting the final reference position marker candidate group provided, and comparing the information about the final reference position marker candidate of the final reference position marker candidate group with the information about the reference position marker to determine the final reference position marker, and the determined final reference position marker An operation control unit for adjusting the current position of the final reference position marker to the reference position by comparing the current position of the reference position marker with the reference position;

A storage unit storing information about the reference position marker having a distance between two reference position markers and an angle formed by the two reference position markers

Including,

The operation control unit,

Determining the pixel group determined by a plurality of preliminary reference position marker candidates by determining a pixel group composed of a plurality of pixels arranged in the row direction and the column direction without a predetermined gray scale value in the photographed image,

Calculating the respective preliminary distances, comparing the distances associated with the calculated preliminary reference position marker candidates with the distances associated with the reference position markers corresponding to the preliminary reference position marker candidates,

If a distance having a value equal to each of the distances associated with the reference position markers corresponding to each of the preliminary reference position marker candidates exists at a distance related to each of the calculated preliminary reference position marker candidates, the respective preliminary reference position marker candidates correspond to each of the preliminary reference position marker candidates. Determining a valid preliminary reference position marker candidate as a candidate of the reference position marker, and determining a valid preliminary reference position marker candidate from the plurality of preliminary reference position marker candidates,

A valid preliminary reference position marker candidate group is determined by combining the effective preliminary reference position marker candidates which are candidates of the reference position marker,

The operation control unit,

If the final reference position marker candidate group does not exist in the selected effective preliminary reference position marker candidate group, it is determined that a candidate of one reference position marker does not exist among the plurality of preliminary reference position marker candidates, and the plurality of preliminary reference positions A device for correcting the position of the reference position marker which performs an operation of determining a new valid preliminary reference position marker candidate to determine whether the candidate is a reference position marker except for one reference position marker that is assumed not to exist using the marker candidate. .
In claim 1,

The operation control unit deletes the valid preliminary reference position marker candidate group in which the same effective preliminary reference position marker is selected as a candidate of different reference position markers from the selected effective preliminary reference position marker candidate group to determine the final reference position marker candidate group. Position correction device.
In claim 1,

The operation control unit may determine a value of the distance between the assumed reference position markers and the angle between the two vectors in the final reference position marker candidates of the final reference position marker candidate group, which is information about the assumed reference position markers for each final reference position marker candidate. And calculating the final reference position marker candidate belonging to the final reference position marker candidate group having the same information as the reference position marker as the final reference position marker.
In the method of correcting the position of the reference position marker,

Performing a process of increasing the brightness value of the acquired reference image;

After the process of increasing the brightness value is performed, a Hough transform is performed to detect a circle. Selecting an optimal circle among the detected circles and selecting the pixel group;

Performing a process of removing noise existing outside the pixel group based on the found pixel group;

Determining the pixel group including a plurality of pixels that are already arranged in the row direction and the column direction from the image acquisition unit and arranged in the row direction and the column direction as the plurality of preliminary reference position marker candidates;

Calculating a distance associated with each preliminary reference position marker candidate by calculating a distance between each preliminary reference position marker candidate and each remaining preliminary reference position marker candidate;

Comparing the distance associated with each of the calculated preliminary reference position marker candidates with the distance associated with the reference position marker corresponding to each preliminary reference position marker candidate,

If a distance having a value equal to each of the distances associated with the reference position markers corresponding to each of the preliminary reference position marker candidates exists at a distance related to each of the calculated preliminary reference position marker candidates, the respective preliminary reference position marker candidates correspond to each of the preliminary reference position marker candidates. Determining a valid preliminary reference position marker candidate as a candidate of the reference position marker, and determining an effective preliminary reference position marker candidate from the plurality of preliminary reference position marker candidates;

Determining a valid preliminary reference position marker candidate group by combining the effective preliminary reference position marker candidates which are candidates of the reference position marker,

Selecting an effective preliminary reference position marker candidate group for the reference position marker,

Selecting a final reference position marker candidate group having a final reference position marker candidate from the selected effective preliminary reference position marker candidate group,

Comparing the information about the last reference position marker candidate of the last reference position marker candidate group with the information about the reference position marker,

Determining whether there is a final reference position marker candidate group having the same information as the information about the reference position marker;

If there is a final reference position marker candidate group having the same information as the reference position marker information, determining a final reference position marker from the hypothesized reference position marker belonging to the existing reference position marker candidate group present;

Comparing the current position of the determined final reference position marker with the reference position of the reference position marker to adjust the current position of the final reference position marker to the reference position,

Determining that there is no candidate of one reference position marker among the plurality of preliminary reference position marker candidates when there is no final reference position marker candidate group having the same information as the information about the reference position marker, and

Using the plurality of preliminary reference position marker candidates, performing an operation of determining a new valid preliminary reference position marker candidate to determine whether it is a candidate of the remaining reference position markers except for one reference position marker that is assumed not to exist. Step; correcting the position of the reference position marker comprising a.
In claim 4,

The selecting of the final reference position marker candidate group includes deleting the effective reference reference position marker candidate group in which the same effective preliminary reference position marker is selected as a candidate of different reference position markers from the selected effective preliminary reference position marker candidate group. A position correction method of a reference position marker for determining a candidate group.
In claim 4,

Determining the final reference position marker,

Calculating a value of an angle between an assumed reference position marker and an angle between two vectors, which is information about an assumed reference position marker for each final reference position marker candidate in the final reference position marker candidate of the final reference position marker candidate group;

Comparing whether the information about the reference position marker and the calculated assumed reference position marker are the same, and

Determining that the last reference position marker candidate belongs to the last reference position marker candidate group as the final reference position marker when there is a final reference position marker candidate group having the same information about the reference position marker and the calculated reference position marker information. Position correction method of the reference position marker comprising a.
In claim 6,

Obtaining a centerline between the markers in the step of comparing whether the information about the reference position marker and the calculated assumed reference position marker are the same;

Obtaining a centerline and obtaining an angle between the two markers using the reference line vector and the starting point of the optimal centerline;

And rotating the image by the obtained angle.