JP5350943B2 - Color code target, color code discrimination device, and color code discrimination method - Google Patents

Abstract

Disclosed is a color code target that facilitates measurement of a reference position of the target, mark detection, and color code identification when an opening is formed at the center of the target. Specifically disclosed is a color code target (TA1) which comprises position mark portions including position marks (P1) for indicating measurement positions, reference color portions including reference color marks (P2) used as chromatic references, color code portions including color code marks (P3) for identifying the color code target (TA1), and mark separation portions including separation marks that separates the marks disposed in a plane. The position marks (P1), the reference color marks (P2), and the color code marks (P3) are annularly disposed along a circumference of a circle having a center at a reference position (C0). An opening (H) is formed at the reference position (C0). The separation marks are disposed so as to have a first predetermined number of the reference color marks (P2) interposed therebetween and so as to have a second predetermined number of the color code marks (P3) interposed therebetween.

Description

  The present invention relates to a color code target, a color code discrimination device, and a color code discrimination method. More specifically, the present invention relates to a color code target in which color code marks that can be identified by each other are arranged in a ring shape, a color code determination device and a color code determination method for the color code target.

  A color code target is a target proposed by the inventors for three-dimensional measurement, and a position code for indicating a measurement position and a color code mark for identifying a target are provided in a plane. With. Targets used for three-dimensional measurement can be individually identified, thereby contributing to full automation of processes from imaging to three-dimensional measurement (see Patent Document 1). The inventors have also proposed an apparatus and method for discriminating a color code of a color code target (see Patent Document 2). These color code targets, color code discriminating apparatuses and color code discriminating methods have been used for three-dimensional measurement of various objects, taking advantage of the feature that the targets can be individually identified. In particular, three-dimensional measurement that requires a large number of targets, such as a vast object or a complex object, is suitable for automatic processing by a computer and enables efficient measurement.

JP 2007-101277 A (paragraphs 0024 to 0076, FIGS. 1 to 20) Japanese Patent Laying-Open No. 2007-101276 (paragraphs 0027 to 0132, FIGS. 1 to 30)

  However, in the scientific and medical fields, there are cases where it is desired to measure the probe position. A large number of attachments are used to measure the EEG response to various stimuli and the activity distribution of brain function. In this case, in order to measure the positions of a large number of probes with high accuracy, it is desired to use a color code target that can identify individual targets. However, it is necessary to arrange the targets while avoiding the positions of the probes. Therefore, it is conceivable to provide an opening into which the probe can be inserted at the center of the target, and to arrange a position mark and a color code mark around the hole. How to measure, how to arrange the position mark and color code mark, how to detect, etc. have not been solved yet.

  The present invention provides a color code target in which when a hole is provided in the center of the color code target, it is easy to measure the reference position of the target, and the position mark and color code mark can be easily detected and the color code can be distinguished The purpose is to do. Another object of the present invention is to provide a color code discriminating apparatus and a color code discriminating method suitable for discriminating the color code of such a color code target.

  In order to solve the above-described problem, the color code targets TA1 to TA3 according to the first aspect of the present invention are, as shown in FIGS. 1 to 3, for example, a position mark portion including a position mark P1 for indicating a measurement position. A reference color portion including a reference color mark P2 to which a color used as a color reference is applied, and a color code portion including a color code mark P3 to which the color code targets TA1 to TA3 are identified. And a mark delimiter section including delimiters for delimiting between the reference color mark P1 and the color code mark P2, between the reference color marks P2 or between the color code marks P3, and the position mark P1 and the reference color The mark P2 and the color code mark P3 are annularly arranged along a circumference centered on the reference position C0 or an outer periphery of a regular polygon, and the reference position C Openings H are provided in, separated marks sandwiching a first predetermined number of the reference color mark P2, are arranged so as to sandwich the second color code marks P3 of a predetermined number.

  Here, the position mark P1, the reference color mark P2, and the color code mark P3 included in the color code targets TA1 to TA3 may be singular or plural. The position mark P1 may also be used as a delimiter mark. Further, a mark including a retro target is typically used as the position mark P1, but other marks such as a template mark may be used as long as the position (point) can be specified. Typically, three primary colors of red (R), green (G), and blue (B) are used for the reference color mark P2, but other colors may be used as long as the hue difference is equal. Each of the color code marks P3 has a color, and the color code portion has a distinctiveness due to a difference in color arrangement (including arrangement) of one or a plurality of color code marks P3 constituting the color code mark P3. It is preferable to include the color of the reference color mark P2 in the color of the color code mark P3 because it is easy and reliable to distinguish, but only other colors may be used. Further, it is preferable to select the hue difference of colors used for the color code mark P3 so as to be uniform in order to clarify the difference between the colors used. Also, if the circumferential width of each mark is the same, the scanning time for mark detection is the same, which is convenient for detecting the position of the mark. For example, if the separation between marks can be clarified, the width of the separation mark May be reduced. In addition, the mark is arranged in an annular shape as long as the mark is arranged around the reference position C0 in the circumferential direction, the mark is not limited to an annular shape and may be arranged in a polygonal shape. In addition, a ring formed by connecting marks arranged in a ring shape along the circumference or the outer periphery of a regular polygon is referred to as a mark ring. The hole H is typically arranged inscribed in the mark ring, but the color code target may have an inner frame region between the mark ring and the hole H. You may have an outer frame area | region on the outer side.

  With this configuration, since the position mark P1 is annularly arranged along the circumference around the reference position C0, the reference position C0 can be easily obtained as the center of a circle connecting the position marks P1. Can do. Further, the position mark P1 can be easily detected by arranging a mark including a retro target as the position mark P1 in a predetermined position on a circular ring or the like. Further, it is possible to accurately and easily determine the color of the color code mark P3 using the reference color mark P2. In addition, the reference color mark P2 and the color code mark P3 can be easily detected by separating the reference color mark P2 and the color code mark P3 using the separation marks and arranging them at fixed positions on a ring or the like. Therefore, when the hole H is provided at the center of the color code targets TA1 to TA3, the measurement of the reference position C0 of the target is easy, and the detection of the position mark P1 and the color code mark P3 and the discrimination of the color code are easy. A color code target can be provided.

Further, in the color code targets TA1 to TA3 according to the second aspect, in the first aspect, for example, as shown in FIGS. 1 to 3, the position mark P1 also serves as a delimiter mark.
With this configuration, it is not necessary to newly provide a delimiter mark, and the position mark P1, the reference color mark P2, and the color code mark P3 can be enlarged correspondingly, and these marks can be easily detected.

The color code targets TA1 to TA3 according to the third aspect are the first predetermined number is 1 and the second predetermined number as shown in FIGS. 1 to 3 in the first or second aspect, for example. The number is a constant of 2 or more.
With this configuration, the reference color mark P2 and the color code mark P3 can be easily distinguished by making the number of reference color marks and the number of color code marks sandwiched between the division marks different.

Further, the color code targets TA1 to TA3 according to the fourth aspect are the same as in any of the first to third aspects, for example, as shown in FIGS. The number of colors used matches, and the colors of the color code marks P3 constituting the color code portion are all different.
With this configuration, since all the code colors are used for the color code mark P3, not only the comparison with the reference color mark P2, but also the relative comparison of the colors between the color code marks P3, The identification code can be determined by confirming the color, and the reliability of the color code discrimination can be improved.

Further, the color code targets TA1 to TA3 according to the fifth aspect are the reference color mark P2 and the color code mark P3 in the first to fourth aspects, for example, as shown in FIGS. It is arranged in a predetermined positional relationship with respect to the position C0.
Here, the predetermined positional relationship typically means that the distance and direction from the reference position C0 are in a certain distance and in a certain direction. If configured in this manner, the reference color mark P2 and the color code mark P3 are arranged at fixed positions on an annular ring or the like, so that they can be easily detected.

The color code targets TA1 to TA3 according to the sixth aspect are any one of the first to fifth aspects. For example, as shown in FIGS. 1 to 3, the position mark P1 is composed of at least six pieces. Arranged so that two congruent or inverted symmetrical triangles can be extracted from the triangles formed by connecting the centers of the position marks P1.
Here, even if the position mark is 7 or more, it is sufficient if two triangles can be extracted. If configured in this manner, two triangles that are congruent or inversion symmetric can be extracted by connecting the center of the position mark P1 (the position of the retro target), so that a triangle was formed in the color code targets TA1 to TA3 being measured. It can be easily determined whether or not the point is a retro target of the position mark P1 to be obtained.

In addition, the color code targets TA1 to TA3 according to the seventh aspect are arranged along the circumference or the outer circumference of a regular polygon in any of the first to sixth aspects as shown in FIGS. The ring of marks arranged in a ring is singular.
With this configuration, when the number of measurement points is relatively small (for example, 720 points or less), a color code target with a simple configuration can be used, and the mark detection and code determination processing is simplified, which is appropriate.

Further, the color code targets TA4 to TA7 according to the eighth aspect are arranged along a circumference or an outer periphery of a regular polygon as shown in FIGS. 12 to 15 in any one of the first to sixth aspects. There are a plurality of mark rings arranged in a ring, and each mark ring is centered on the reference position C0.
With this configuration, when the number of measurement points is relatively large (for example, more than 720 points), the number of identifiable codes can be increased by multiplication (in the case of a double ring, the number of codes in the first ring is A, When the number of codes in the second ring is B, the total number of codes is A × B, and in the case of a triple ring, the total number of codes is further increased).

Further, the color code targets TA1 to TA3 according to the ninth aspect are the position marks P1 arranged on the ring of one mark in the seventh or eighth aspect, for example, as shown in FIGS. The reference color mark P2 and the color code mark P3 are unified with the same shape and size.
If comprised in this way, since the shape and dimension of each mark arrange | positioned on a ring etc. are equal, detection of each mark will become easy and reliable.

The set of color code targets according to the tenth aspect is a set of color code targets configured by combining a plurality of color code targets TA according to any of the first to ninth aspects, and each color code target In the code target TA, the position mark P1, the reference color mark P2, and the color code mark P3 are arranged at the same position on the mark ring, the arrangement of the colors of the reference color mark P2 is the same, and the color of the color code mark P3 is the same. All arrangements are different.
With this configuration, each color code target TA that constitutes a set of color code targets differs only in the color arrangement of the color code mark P3, so that the color code can be determined by the same processing procedure. Suitable for automating code discrimination processing. The symbol TA is used to generically indicate the color code target according to the present invention.

  Moreover, the color code discrimination device 1 according to the eleventh aspect, for example, as shown in FIG. 6, a target image acquisition unit 31 that acquires images of the color code targets TA1 to TA3 according to the first aspect from at least two different directions. The position mark detection unit 51 that sequentially detects the position marks P1 from the images of the color code targets TA1 to TA3 acquired from at least two different directions by the target image acquisition unit 31, and the position mark detection unit 51 sequentially detects them. A reference position calculation unit 63 for obtaining the reference position C0 of the color code targets TA1 to TA3 from the arrangement of the position mark P1, and a circumference or a regular polygon outer periphery centered on the reference position C0 obtained by the reference position calculation unit 63 A mark arrangement detector 72 for sequentially detecting marks arranged in a ring shape along the line, and mark arrangement A reference color mark extraction unit 73 that sequentially extracts the reference color mark P2 from the ring of marks detected by the output unit 72, and a color code that sequentially extracts the color code mark P3 from the ring of marks detected by the mark arrangement detection unit 72 The color code mark P3 is compared with the color of each reference color mark P2 extracted by the mark extraction unit 74 and the reference color mark extraction unit 73 and the color of each color code mark P3 extracted by the color code mark extraction unit 74. A color code discriminating unit 75 that discriminates a color code from the arrangement of the colors, a color code that stores the reference position C0 obtained by the reference position calculating unit 63 and the color code discriminated by the color code discriminating unit 75 in association with each other. A storage unit 85.

  Here, the sequential extraction from the mark ring means that the mark ring is extracted in the order of arrangement from the designated or designed position. The color comparison is typically made by comparing the intensity ratios of the detection light of the three primary colors, but the spectra may be compared. With this configuration, the position mark detection unit 51 detects the position mark P1 arranged in an annular shape along the circumference around the reference position C0, and the reference position calculation unit 63 detects the position mark P1. Therefore, the reference position C0 can be easily obtained using the reference position C0 as the center of a circle or the like connecting the position marks P1. Further, the reference color mark P2 and the color code mark P3 arranged in an annular shape are extracted by the reference color mark extraction unit 73 and the color code mark extraction unit 74, and the colors of these marks are compared by the color code determination unit 75. Since the color code is discriminated, the color code can be discriminated accurately and easily. Therefore, it is possible to provide a color code determination apparatus suitable for determining the color code of the color code target TA according to the present invention.

Further, the color code discrimination device 1 according to the twelfth aspect detects the mark arrangement based on the arrangement of the position marks P1 sequentially detected by the position mark detection unit 51 in the eleventh aspect, for example, as shown in FIG. The unit 72 includes a starting point calculation unit 71 for obtaining a starting point for detecting a mark arranged in a ring shape, and the mark placement detecting unit 72 sequentially detects the mark from the starting point obtained by the starting point calculation unit 71.
If comprised in this way, the starting point and order of mark detection can be determined easily, and efficient mark detection can be performed. This starting point can also be used as a starting point for the arrangement of color code marks.

  Further, the color code determination method according to the thirteenth aspect includes, for example, a target image acquisition step (S100) for acquiring an image of the color code target according to the first aspect from at least two different directions, as shown in FIG. A position mark detection step (S110) for sequentially detecting the position marks P1 from the images of the color code targets TA1 to TA3 acquired from at least two different directions in the target image acquisition step (S100), and a position mark detection step (S110). A reference position calculation step (S120) for obtaining the reference position C0 of the color code targets TA1 to TA3 from the respective positions of the detected position marks P1 and the reference position C0 obtained in the reference position calculation step (S120). Marks arranged in a circle along the circumference of a circle or regular polygon A mark arrangement detecting step (S140) to detect, a reference color mark extracting step (S150) for sequentially extracting each reference color mark P2 from the ring of marks detected in the mark arrangement detecting step (S140), and a mark arrangement detecting step ( A color code mark extraction step (S160) for sequentially extracting the color code mark P3 from the ring of marks detected in S140), and the color and color code of each reference color mark P2 extracted in the reference color mark extraction step (S150) A color code determination step (S170) for comparing the colors of the color code marks P3 extracted in the mark extraction step (S160) to determine a color code from the color arrangement of the color code mark P3, and a reference position calculation step ( The reference position C0 obtained in S120) and the color code determined in the color code determining step (S170). In association with each other and de and a color code storage step (S180).

  If comprised like this aspect, the position mark P1 arrange | positioned cyclically | annularly along the circumference etc. centering on the reference position C0 in the position mark detection process (S110) will be detected, and a reference position calculation process (S120) will be carried out. Since the reference position C0 is obtained from the position mark, the reference position C0 can be easily obtained as the center of a circle or the like connecting the position marks P1. Further, the reference color mark P2 and the color code mark P3 arranged in the annular shape are extracted in the reference color mark extraction step (S150) and the color code mark extraction step (S160), and these are extracted in the color code discrimination step (S170). Since the color code is determined by comparing the colors of the marks, the color code can be determined accurately and easily. Therefore, it is possible to provide a color code determination method suitable for determining the color code of the color code target TA according to the present invention.

In addition, in the thirteenth aspect, for example, as shown in FIG. 7, the color code determination method according to the fourteenth aspect is based on the arrangement of the position marks P1 sequentially detected in the position mark detection process. A starting point calculating step (S130) for obtaining a starting point for detecting the circularly arranged marks in S140) is provided, and the mark placement detecting step (S140) sequentially detects the marks from the starting points obtained in the starting point calculating step (S130).
If comprised in this way, the starting point and order of mark detection can be determined easily, and efficient mark detection can be performed.

  According to the present invention, when a hole is provided in the center of the color code target, it is easy to measure the reference position of the target, and it is easy to detect the position mark and the color code mark and to distinguish the color code. Can provide. In addition, a color code determination apparatus and a color code determination method suitable for determining the color code of the color code target can be provided.

3 is a diagram illustrating an example of a color code target TA1 in Embodiment 1. FIG. FIG. 3 is a diagram illustrating an example of a color code target TA2 in the first embodiment. 6 is a diagram illustrating an example of a color code target TA3 in Embodiment 1. FIG. It is a figure which shows the relationship between the reference position of a color code target, and a position mark. It is a figure which shows the positional relationship between each position mark. It is a figure which shows the structural example of a color code discrimination device. It is a figure which shows the example of a processing flow of a color code discrimination method. It is explanatory drawing of the gravity center position detection using a retro target. It is a figure which shows the example of a processing flow mainly having the mark arrangement | positioning detection of a color code target. It is a figure for demonstrating confirmation of the position mark by DLT method. It is a figure for demonstrating mutual orientation. 6 is a diagram illustrating an example of a color code target TA4 in Embodiment 2. FIG. 6 is a diagram illustrating an example of a color code target TA5 in Example 3. FIG. It is a figure which shows the example of the color code target TA6 in Example 4. FIG. It is a figure which shows the example of the color code target TA7 in Example 5. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

[Color code target]
1 to 3 show examples of color code targets TA1 to TA3 in the first embodiment. In this embodiment, the target is a circular shape, and a circular hole H centered on the reference position C0 is formed at the center, which is the reference position C0, and is positioned along the circumference centered on the reference position C0. An example in which the mark P1, the reference color mark P2, and the color code mark P3 are annularly arranged will be described. 1 to 3 differ in the radial width of marks arranged in an annular shape along the circumference, but the arrangement of the marks is the same. The width of the ring (ring) is small in FIG. 1, medium in FIG. 2, and large in FIG. Further, the position mark P1, the reference color mark P2, and the color code mark P3 are arranged in an annular shape (ring shape) along the circumference centered on the reference position C0. A ring formed by connecting marks arranged in a ring along the circumference is called a mark ring (also simply called a ring). Further, the color code targets TA1 to TA3 in which the marks are arranged in an annular shape are referred to as ring color targets. The position mark P1 is a mark indicating the measurement position, the reference color mark P2 is a mark provided with a color used as a color reference, and the color code mark P3 is a mark provided with a color for identifying a target. The delimiter mark is a mark that delimits between the reference color mark and the color code mark, between the reference color marks, or between the color code marks. In this example, the position mark P1 also serves as a delimiter mark. In this example, the first predetermined number is 1 and the second predetermined number is 2.

  The inner diameter of the mark ring is determined by the outer diameter of a probe or the like inserted into the hole, and varies depending on the probe. Also, the outer diameter of the mark ring varies depending on the inner diameter. As for the ring, it is preferable to take the width of the mark ring so that each mark arranged along the circumference can be sufficiently recognized, for example, the width is set to 1 to 100 mm. For example, in the example of FIG. 1, the outer diameter of the ring is 50 mm and the inner diameter is 45 mm, in the example of FIG. 2, the outer diameter of the ring is 60 mm, the inner diameter is 40 mm, and in the example of FIG. Can be mentioned. In FIG. 2 and FIG. 3, a plurality of line segment marks or cross marks (which may not be present) toward the center of the circle are seen in the vicinity of the ring, but this is for making it easy to find the center.

  The position mark portion is composed of one or a plurality of position marks P1. The position mark P1 is a mark for indicating a measurement position. In this embodiment, the circular opening H is arranged at the center of the circle at the reference position C0, and the position mark P1, the reference color mark P2, and the color code mark P3 are annular along the circumference centered on the reference position C0. It is arranged in a (ring shape). The position mark P1 has a small and circular retroreflective function at the center of the black mark (indicated by BL in the figure) (on the symmetry line in the circumferential direction and between the inner and outer diameters in the radial direction). (Retro target) is provided. In order to enable position detection, a small retro target preferably has a certain size or more. For example, the outer diameter is about half of the radial width of the mark ring. In this embodiment, the position mark P1 also serves as a delimiter mark. The reason for the black background is to clarify the difference from the retro target to facilitate position detection, and to clarify the separation between one or more marks as the separation marks. There are six position marks P1, which are arranged in the first, third, fifth, eighth, tenth and thirteenth positions, counting clockwise from the position mark P10 located above the opening H as the first position mark. In the present embodiment, an example in which the position mark P1 includes a retro target will be described. However, instead of the retro target, a small and circular white mark formed by white coating on a black background may be used.

  FIG. 4 shows the relationship between the reference position C0 and the position mark P1 of the color code targets TA1 to TA3. The position mark P1, the reference color mark P2, and the color code mark P3 are arranged in an annular shape (ring shape) along the circumference centered on the reference position C0. There is an opening H at the center of the circle. The reference position C0 is located at the center of the circle on the plane including these marks.

  FIG. 5 shows the positional relationship between the position marks P1. The position mark P10 positioned above the opening H is counted as the first, and the first triangle T1 connecting the centers of the retro targets of the first, third and thirteenth marks is positioned above the opening H. A second triangle T2 connecting the centers of the retro targets of the fifth, eighth and tenth marks is formed counting clockwise from the position mark P10 as the first. The shapes of the first triangle T1 and the second triangle T2 are congruent, and the longest side of the first triangle T1 and the longest side of the second triangle T2 are straight lines (in the horizontal direction) that divide the mark ring into upper and lower halves. (Diameter). Therefore, when the position mark P1 is detected, detection is facilitated by finding the two triangles T1 and T2 having such a relationship. Note that an inverted symmetrical triangle may be used instead of the congruent triangle. Each position mark P1 is arranged in a predetermined positional relationship (a fixed distance, a fixed direction) with respect to the reference position C0. Therefore, the positional relationship (distance and direction) between the first triangle T1 (vertex, side) and the second triangle T2 (vertex, side) is also constant.

  Six position marks P1 are arranged on the ring. Thus, using a single photo orientation or DLT (Direct Linear Transformation) method, or a combination of the DLT method and bundle adjustment, 6 points on the ring (position mark) from a large number of candidate points on the photographed image. The center point of P1) can be detected with high accuracy. Of these six points, the upper three points form the first triangle T1, the lower three points form the second triangle T2, and the shapes of the first triangle T1 and the second triangle T2 are congruent. The longest side of the first triangle T1 and the longest side of the second triangle T2 are arranged to face each other. For this reason, if the search is divided into the upper three points and the lower three points rather than searching for six points at once, it is only necessary to search for one triangle, and an efficient search can be performed. For example, if there are 10 candidate points, if 6 points are collectively searched, 2 triangles will be searched from a maximum of 100,000 ways, but if divided into 3 points and 3 points, the search will be 1 from a maximum of 100 ways. One triangle may be searched, and then the corresponding triangle may be searched. Corresponding triangle shapes are congruent, and the longest sides of both faces each other, so the candidate points for the search are considerably narrowed down and can be searched efficiently. The orientation and DLT method will be described later.

  The reference color portion is composed of one or a plurality of reference color marks P2. The reference color mark P2 is a mark provided with a color to be used as a color reference. In this embodiment, red (indicated by R in the figure), green (indicated by G in the figure), and blue (indicated by B in the figure). Three colors are used. In addition, here, both sides are sandwiched between position marks (separation marks) P1, and the position mark P10 located above the opening H is first, and the second, fourth, and ninth positions are counted clockwise. Yes. The reference color mark P2 is used for reference during a relative comparison and for color calibration for correcting the color misregistration in order to cope with color misregistration due to photographing conditions such as illumination and a camera. Furthermore, the reference color mark P2 can be used for color correction of a color code target created by a simple method. For example, when using a color code target printed by a color printer (inkjet, laser, sublimation type printer, etc.) that is not color-controlled, individual differences appear in the color of the printer used, but the reference color mark P2 By comparing and correcting the color of the color code mark P3, the influence of individual differences can be suppressed. As described above, the color of the reference color mark P2 can be used for correcting the color of the measurement object 2 in addition to correcting the color of the color code mark P3.

The color code portion is composed of one or a plurality of color code marks P3. The color code mark P3 is a mark provided with a color for identifying the target. In this embodiment, red (indicated by R in the figure), green (indicated by G in the figure), blue (indicated by B in the figure). ), Yellow (indicated by Y in the figure), cyan (indicated by C in the figure), and magenta (indicated by M in the figure). Each of the two color code marks P3 is sandwiched between position marks (separation marks) P1 on both sides, and the position mark P10 located above the opening H is counted first in the clockwise direction. , 11, 12th, 14th, 15th. The color code mark portion expresses a code by a combination of color schemes of the color code marks constituting the color code mark portion. The number of codes that can be expressed varies depending on the number of code colors used for the code. For example, when the number of code colors is n, the color code target TA can represent n ⁿ codes when the number of color code marks P3 is n. In order to increase the reliability, even if the condition that the colors used for other unit marks are not used redundantly, n! Express street code. If the number of code colors is increased, the number of codes can be increased. Furthermore, if the condition that the number of color code marks P3 is equal to the number of code colors is imposed, all the code colors are used for the color code mark P3. Therefore, not only the comparison with the reference color mark P2, but also the color code mark By relatively comparing the colors between P3, the color of each color code mark P3 can be confirmed to determine the identification code, and the reliability can be improved. Furthermore, adding a condition for making the areas of the respective color code marks P3 the same is also useful when the color code target TA is detected from the image. This is because the area occupied by each color is the same even between color code targets having different identification codes, so that almost the same dispersion value is obtained from the detection light from the entire color code target TA. Further, since the boundary between the color code marks P3 is repeated at equal intervals and a clear color difference is detected, it is possible to detect the color code target TA from the image by repeating such detection light. .

  The mark delimiter is composed of a plurality of delimiter marks. The delimiter mark is a mark that delimits between the reference color mark P2 and the color code mark P3, between the reference color marks P2 or between the color code marks P3. In this embodiment, the delimiter mark also serves as the position mark P1. It has a retro target in the center and is black (indicated by BL in the figure). In addition, each reference color mark P2 is sandwiched between the separator marks P1 on both sides, and two color code marks P3 are sandwiched between the separator marks P1 on both sides, resulting in the first predetermined number. Is 1, and the second predetermined number is 2. The delimiter mark P1 is arranged in the first, third, fifth, eighth, tenth, and thirteenth positions when the position mark P10 located above the opening H is counted first and counted clockwise. The first, fifth, eighth and tenth division marks counting clockwise from the position mark P10 positioned above the opening H as the first division mark between the reference color mark P2 and the color code mark P3 are 3 The th delimiter mark is a mark that delimits the reference color marks P2, and the thirteenth delimiter mark is a mark that delimits the color code marks P3.

  When one set of color code targets is constituted by the color code targets TA1 to TA3, targets having the same shape and dimensions are used for the color code targets TA1 to TA3. In addition, an opening H is provided at the center, and the position mark P1, the reference color mark P2, and the color code mark P3 are arranged at the same position on the ring of marks arranged in a ring shape along the circumference. Further, the color arrangement of the reference color mark P2 is the same, and the combinations of the color arrangements of the color code mark P3 are all different. For n = 6, one set has 720 different color code targets TA. This makes it possible to efficiently perform measurement that is suitable for automatic processing by a computer in a three-dimensional measurement that requires a large number of targets with a target that has an aperture that allows insertion of a probe, etc., taking advantage of the feature that the target can be identified. It becomes.

[Color code discrimination device]
FIG. 6 shows a configuration example of the color code discrimination device 1. The color code discriminating apparatus 1 includes, for example, an imaging unit 3 that captures an image of the measurement object 2, an input / output unit 4 that displays captured images and processed images, and an input / output operation. A feature extraction unit 5 that extracts feature points, a three-dimensional position measurement unit 6 that measures the three-dimensional position and shape of the measurement object 2, an image processing unit 7 that performs various image processing on the captured image, a captured image, a mark, and a measurement A storage unit 8 that stores a position and the like, a color code determination device 1 and a control unit 9 that controls the respective units and functions as the color code determination device 1 are configured. Among these, the feature extraction unit 5, the three-dimensional position measurement unit 6, the image processing unit 7, and the control unit 9 can be realized using the functions of the personal computer PC 10 and are configured in the PC 10.

  The imaging unit 3 includes a stereo camera or a single camera for imaging the measurement object 2, and includes a target image acquisition unit 31 that acquires images of the color code targets TA1 to TA3 from the captured image. In this embodiment, the target image acquisition unit 31 acquires images from at least two different directions. The input / output unit 4 includes a display unit 41 that displays images and operation screens, an output unit 42 that includes a printer, a speaker, and the like, and an input unit 43 that includes a mouse, a keyboard, and the like. The feature extraction unit 5 sequentially detects the position mark P1 from the images of the color code targets TA1 to TA3 acquired by the target image acquisition unit 31, and extracts feature points for three-dimensional measurement from the captured image. A feature point extraction unit 52. In the present embodiment, the position mark detection unit 51 sequentially detects the position mark P1 from images acquired from at least two different directions. The feature points include, for example, the center position and corner position of the measurement object 2, positions having different characteristics from others, targets attached to or projected on the measurement object 2, and the like. Therefore, the position mark P1 can also be handled as one of the feature points, but here, the position mark detection unit 51 is distinguished as performing a specific process. Therefore, the feature point extraction unit 52 extracts features other than the color code target, for example, feature points for three-dimensional measurement in the measurement object 2. The three-dimensional measuring unit 6 searches for a corresponding point corresponding to a feature point in one image (reference image) from a captured image that forms a stereo pair in the other image (search image) (in the case of a color code target, identification is performed). A corresponding point search unit 61 that searches for the same corresponding point (such as a retro target of the position mark P1) based on the color code that has been recorded, an orientation unit 62 that obtains the position and inclination of the camera in the stereo image, and a position mark detection The reference point calculation unit 63 for obtaining the three-dimensional coordinates of the reference position C0 of the color code targets TA1 to TA3 from the arrangement of the position marks P1 sequentially detected by the unit 51, and the feature points (corresponding to the correspondence points search unit 61) A three-dimensional coordinate calculation unit 64 for obtaining three-dimensional coordinates of the point) and the camera position. Although the position mark can also be handled by including it as a feature point (measurement point), here, the reference position calculation unit 63 is distinguished as obtaining three-dimensional coordinates of the reference position C0.

  The image processing unit 7 sequentially detects marks arranged in a ring shape along the circumference centered on the reference position C0 obtained by the reference position calculation unit 63 and a starting point calculation unit 71 for obtaining a starting point for detecting the mark. An arrangement detection unit 72, a reference color mark extraction unit 73 for sequentially extracting each reference color mark P2 from the mark ring detected by the mark arrangement detection unit 72, and a color code mark from the mark ring detected by the mark arrangement detection unit 72 The color code mark extraction unit 74 that sequentially extracts P3 and the color of each reference color mark P2 extracted by the reference color mark extraction unit 73 are compared with the color of each color code mark P3 extracted by the color code mark extraction unit 74. And a color code determining unit 75 for determining a color code from the color arrangement of the color code mark P3. The storage unit 8 stores a captured image storage unit 81 that stores captured images, a reference position C0, and a three-dimensional position storage unit 82 that stores three-dimensional position coordinates of measurement points (including the center of the retro target of the position mark P1). A reference color mark storage unit 83 that stores the color data of each reference color mark P2 sequentially extracted by the color mark extraction unit 73, and the color data of each color code mark P3 that is sequentially extracted by the color code mark extraction unit 74 are stored. The color code mark storage unit 84 includes a color code storage unit 85 that stores the reference position C0 obtained by the reference position calculation unit 63 and the color code P3 determined by the color code determination unit 75 in association with each other. The color code discriminating unit 75 has a color-code correspondence table that records the correspondence between the color data, each reference color, and each color code color, and a plurality of types of color code targets that are planned to be used. For TA, the type code number indicating the type of the color code target TA is recorded, and for each color code target TA, the correspondence between the mark arrangement (color arrangement, that is, single color code arrangement) and the target code number is shown. It has a color code target correspondence table to be recorded, and is used for color code discrimination.

[Color code discrimination processing flow]
FIG. 7 shows a processing flow example (outline) of the color code discrimination method for the color code targets TA1 to TA3. First, the target image acquisition unit 31 acquires images of the color code targets TA1 to TA3 (target image acquisition step: S100). In this embodiment, images from at least two different directions are acquired. Next, the position mark detection unit 51 sequentially detects the position mark P1 from the images of the color code targets TA1 to TA3 acquired in the target image acquisition step (S100) (position mark detection step: S110). In this embodiment, the position mark P1 is sequentially detected from images acquired from at least two different directions. Next, the reference position calculation unit 63 obtains the reference position C0 of the color code targets TA1 to TA3 from the arrangement of the position marks P1 sequentially detected in the position mark detection process (S110) (reference position calculation process: S120). . Next, the starting point calculation unit 71 obtains a starting point for detecting the mark from the arrangement of the position marks P1 (starting point calculating step: S130). Next, the mark arrangement detection unit 72 sequentially detects marks arranged in an annular shape along the circumference centered on the reference position C0 obtained in the reference position calculation step (S120) (mark arrangement detection). Step: S140). Next, the reference color mark extraction unit 73 sequentially extracts the reference color mark P2 from the mark ring detected in the mark arrangement detection step (S140) (reference color mark extraction step: S150), and the reference color mark storage unit. At 83, the color data of each reference color mark P2 extracted sequentially is stored (reference color mark storage step: S155). Next, the color code mark extraction unit 74 sequentially extracts the color code mark P3 from the mark ring detected in the mark arrangement detection step (S140) (color code mark extraction step: S160), and the color code mark storage unit. At 84, the color data of each color code mark P3 extracted sequentially is stored (color code mark storage step: S165). Next, the color code discriminating unit 75 calculates the color of the reference color mark P2 extracted in the reference color mark extraction step (S150) and the color of the color code mark P3 sequentially extracted in the color code mark extraction step (S160). In comparison, the color code is determined from the color arrangement of the color code mark P3 (color code determination step: S170). Next, the color code storage unit 85 stores the reference position C0 obtained in the reference position calculation step (S120) and the color code determined in the color code determination step (S170) in association with each other (color code storage). Step: S180).

  Details of the flow will be described below. In the position mark detection step (S110), six position marks P1 arranged on the ring are searched and detected. A retro target or a white target is used at the center of the position mark P1. Since the color code portion P3 of the color code target TA has a feature that a large number of code colors are used and the color dispersion value is large, a portion having a large dispersion value of the color code portion P3 is found from the image. Thus, the color code target TA can be detected. Thereafter, the retro target of the position mark P1 may be detected within the range of the color code target TA. In the reference position mark calculation step (S120), the reference position C0 of the color code targets TA1 to TA3 is obtained from the arrangement of the position marks sequentially detected in the position mark detection step (S110).

  FIG. 8 is an explanatory diagram of center-of-gravity position detection using a retro target. However, the process is the same for a white circular target formed with white paint on a black background instead of a retro target. In this embodiment, the retro target is formed by two concentric circles, but the outer side is not necessarily a circle. In FIG. 8A1, the brightness of the inner circle portion 204 that is the inner side of the small circle among the concentric circles is bright, and the brightness of the outer circle portion 206 that is an annular portion formed between the small circle and the great circle is dark. The retro target 200, FIG. 8 (A2) is a brightness distribution diagram in the diameter direction of the retro target 200 of (A1), and FIG. 8 (B1) is a retro target in which the brightness of the inner circle portion 204 is dark and the brightness of the outer circle portion 206 is bright. 200 and FIG. 8 (B2) show the brightness distribution diagram in the diameter direction of the retro target 200 of (B1). When the retro target is bright as shown in FIG. 8 (A1), the light intensity distribution of the image is high because the reflected light at the center of gravity is large and bright in the captured image of the measurement object 2. As shown in FIG. 8A2, it is possible to determine the inner circle portion 204 and the center position of the retro target from the threshold value To of the light amount distribution. In addition, since the small circle which shows a center position is provided in the center of two concentric circles, the small dip has arisen in the center of a brightness distribution map. When a retro target is used, there is an advantage that the amount of reflected light is large and easy to detect. The white circular target is easy to manufacture.

When the target existence range is determined, the barycentric position is calculated by, for example, the moment method. For example, the plane coordinates of the retro target 200 shown in FIG. 8A1 are (x, y). Then, (Expression 1) and (Expression 2) are calculated for points in the x and y directions where the brightness of the retro target 200 is greater than or equal to the threshold value To (* is a multiplication operator).
xg = {Σx * f (x, y)} / Σf (x, y) ---- (Equation 1)
yg = {Σy * f (x, y)} / Σf (x, y) ---- (Formula 2)
(Xg, yg): coordinates of the center of gravity position, f (x, y): density value on (x, y) coordinates In the case of the retro target 200 shown in FIG. 8 (B1), the brightness is the threshold. (Expression 1) and (Expression 2) are calculated for points in the x and y directions that are less than or equal to the value To. Thereby, the position of the center of gravity of the retro target 200 is obtained .

  In order to obtain three-dimensional position coordinates, feature points are extracted by the feature extraction unit 5 (here, the position mark P1 is detected) using images taken from at least two directions as a stereo pair, and are determined by the color code determination unit 75. Using the result, the corresponding point of the code identified by the corresponding point search unit 61 (such as a retro target of the position mark P1) is obtained, the orientation unit 62 obtains the position and inclination of the camera by orientation, and the 3D position computation unit 64 (Here, the reference position calculation unit 63) obtains the three-dimensional position coordinates. A stereo method is typically used to calculate the three-dimensional position coordinates. In order to obtain the three-dimensional position coordinates of feature points that are not color codes, feature points are extracted by the feature extraction unit 5 using images taken with a stereo camera or images taken from at least two directions as stereo pairs. The search unit 61 searches for corresponding points, the orientation unit 62 obtains the position and tilt of the camera by orientation, and the 3D position computation unit 64 obtains 3D position coordinates.

  FIG. 9 shows an example of a processing flow mainly for detecting the color code target mark arrangement. Refer to FIG. 5 for the mark arrangement detection. Please refer to FIG. 7 in a timely manner. First, all the candidate position marks P1 of the color code targets TA1 to TA3 are detected (S210). The coordinates of the position mark P1 are detected by a small circular retro target at the center. However, in this embodiment, the range is not limited to one color code target TA, and all measured ranges are detected. This step corresponds to the position mark detection step (S110). Details of this step are as described in FIG. Next, all triangles (candidates for the first triangle T1 and the second triangle T2) are detected from the position mark candidates detected in (S210) (S220). At this time, from the lengths of the sides of the triangle formed by connecting the detected position mark candidates and the angle formed by the two sides, the candidates for the triangles to be obtained (first triangle T1 and second triangle T2) are determined. Exclude those that do not. If it can be regarded as a candidate of the triangle (first triangle T1 or second triangle T2) to be obtained from the length of the sides of the triangle and the angle formed by the two sides, the candidate of the first triangle T1 or the second triangle T2 And decide. Subsequently, from the triangles (candidates T1 and T2) detected in (S220), the corresponding triangles (the shapes are congruent and have the longest sides facing each other) are detected, and the color code target (ring color code) is detected. Target) Six candidates of position marks P1 of TA1 to TA3 are detected (S230). These steps correspond to the previous stage of the reference position calculation step (S120). That is, an arbitrary triangle is selected from the determined candidates for the triangle (T1, T2) to be a temporary triangle T1, and then any other one of the determined candidates for the triangle (T1, T2) is selected. If two triangles are selected as a temporary triangle T2, the shape is congruent from the positional relationship (distance and direction (direction) from the triangle T1) with the temporary triangle T1, and the longest sides of each other are facing each other Check whether or not. Each position mark P1 is arranged in a predetermined positional relationship (a fixed distance, a fixed direction) with respect to the reference position C0. Therefore, the positional relationship between the first triangle T1 (vertex, side) and the second triangle T2 (vertex, side) is also a fixed relationship (distance and direction (direction)). If it can be regarded as the first triangle T1 and the corresponding second triangle T2 to be obtained from this relationship, 6 as the center of the position mark P1 located at the apex of the formed first triangle T1 and second triangle T2. Detect points.

  Next, the positions of the six points at the center of the position mark P1 are confirmed using the single photo orientation or the DLT method or by combining the DLT method and the bundle adjustment (S240). This step corresponds to the latter stage of the reference position calculation step (S120). It is confirmed whether or not the six points detected as the center of the position mark P1 of the color code target TA are arranged at the designed position of the color code target (ring color code target) TA, and whether or not the triangle is to be obtained. Confirm. The calculation of the DLT method and the bundle adjustment is performed by, for example, the three-dimensional position calculation unit 64, and the reference position calculation unit 63 obtains the calculation result.

（式３−１）に対し、分母を消去すると、次の線形式を導き出せる。

（式３−３）を直接、最小二乗法を用いて解くと、写真座標と対象点座標との関係を決定するＬ_１〜Ｌ_１１の１１個の未知変量を取得できる。 [DLT calculation formula]
The three-dimensional DLT (Direct Linear Transformation) method is a method of reconstructing the positions of marks measured from various directions into three-dimensional coordinates using two or more cameras based on the principle of triangulation.
The DLT method approximates the relationship between the photograph coordinates and the three-dimensional coordinates (target point coordinates) of the subject by a cubic projective transformation equation.
The basic expression of the DLT method is (Expression 3-1).

If the denominator is deleted from (Equation 3-1), the following linear form can be derived.

If (Expression 3-3) is solved directly using the least square method, 11 unknown variables L _{1 to} L ₁₁ that determine the relationship between the photographic coordinates and the target point coordinates can be acquired.

FIG. 10 is a diagram for explaining confirmation of the position mark P1 by the DLT method. When eleven unknown variables L _{1 to} L ₁₁ are known, the relationship between the photographic coordinates (x, y) (CCD plane) and the target point coordinates (X, Y, Z) is known, and the photographic coordinates (x, The position and direction (0, 0, 0, κ, φ, ω) of the camera on the line connecting y) and the target point coordinates (X, Y, Z) are obtained. As a result, the position mark P1 is known from the design data (there are six points on the ring), so the color code target TA (ring color code target) obtained for the six points detected as the position mark P1. ) Can be determined.

[orientation]
Next, a method for obtaining the camera position and tilt by the relative orientation method will be described. The orientation is performed by the orientation unit 62.
A model image refers to a three-dimensional image obtained when a subject is reproduced from two or more three-dimensional photographs. Forming relatively similar model images is called relative orientation. That is, the relative orientation determines the position and inclination of the projection center of each of the left and right cameras so that two corresponding light beams of the stereoscopic photograph meet.

FIG. 11 is a diagram for explaining relative orientation. Next, the details of the orientation calculation of each model image will be described. By this calculation, the positions of the left and right cameras (three-dimensional coordinates and three-axis tilt) are obtained.
The parameters relating to the positions of these cameras are obtained by the following coplanar conditional expression.

The origin of the model coordinate system is taken as the left projection center, and the line connecting the right projection centers is taken as the X axis. For the scale, the base line length is taken as the unit length. The parameters to be obtained at this time are the rotation angle κ ₁ of the left camera, the rotation angle φ _{1 of} the Y axis, the rotation angle κ _{2 of the} right camera, the rotation angle φ ₂ of the Y axis, and the rotation of the X axis. the five of the rotation angle of the corner ω _2. In this case, since the rotation angle ω ₁ of the X axis of the left camera is 0, it is not necessary to consider.

Under such conditions, the coplanar conditional expression of (Equation 4) becomes (Equation 5), and each parameter can be obtained by solving this expression.

Here, between the model coordinate system XYZ and the camera coordinate system xyz, the following coordinate transformation relational expressions (Expression 6) and (Expression 7) hold.

Using these equations, unknown parameters are obtained by the following procedure.
(A) The initial approximate value of the unknown parameter is normally 0.
(B) The coplanar conditional expression (Expression 5) is Taylor-expanded around the approximate value, and the value of the differential coefficient when linearized is obtained by (Expression 6) and (Expression 7), and the observation equation is established.
(C) A least square method is applied to obtain a correction amount for the approximate value.
(D) Correct the approximate value.
(E) Using the corrected approximate value, the operations (b) to (d) are repeated until convergence.
By obtaining unknown parameters (κ ₁ , φ ₁ , κ ₂ , φ ₂ , ω ₂ ), the position and tilt of the camera can be obtained.

バンドル調整を用いることにより、ＤＬＴ法単独を用いるよりもさらに高精度の確認ができる。 [Bundle adjustment]
The bundle adjustment is performed in order to appropriately match the position coordinates of the measurement points between the plurality of captured images. The collinear conditional expression that is a basic expression for bundle adjustment that the projection center, the photographic image, and the measurement object are in a straight line is as follows.

By using bundle adjustment, it is possible to confirm with higher accuracy than using the DLT method alone.

  Returning now to FIG. 9 (see FIG. 7). In the starting point calculating step (S130), the starting point calculating unit 71 determines a starting point for detecting the mark from the arrangement of the position marks P1. For example, the position mark P10 that belongs to the first triangle T1 connecting the position marks P1 and is located above the opening H can be determined as the detection starting point. Note that the starting point is not limited to the position mark P10 located above the opening H. For example, the position mark P10 located above the opening H, which is located to the right of the reference position C0, is counted 4 in the clockwise direction. The second reference color mark may be used as the starting point. Next, it is determined whether or not the color code target (ring color code target) TA1 to TA3 is to be obtained from the detected color arrangement of the ring, and the reference color and the color code color are compared (S250). This process extends from the mark arrangement detection process (S140) to the color code mark storage process (S165). In the mark arrangement detection step (S140), marks arranged in an annular shape along the circumference centered on the reference position C0 are sequentially detected. For example, the position mark P10 located above the aperture H is scanned as a detection starting point, and the color data of the reference color mark P2, the color code mark P3, and the position mark P1 arranged on the ring is collected. To do. At this time, based on the detected coordinates of the six position marks P1, the position coordinates of the reference color mark P2 and the color code mark P3 are converted according to the design values of the color code targets TA1 to TA3 (for example, affine conversion). And ask. Then, it is checked whether or not the obtained positions of the reference color mark P2 and the color code mark P3 are colored as designed. By design, the reference color mark P2 is the position mark P10 located above the opening H, and the position mark P10 is counted as the first, and the second, fourth, and ninth marks are red, green, and blue as position marks. The color code mark P3 is sandwiched between P1, and the color code mark P3 is counted in the sixth, seventh, eleventh, twelfth, fourteenth, fifteenth, six colors, counting clockwise from the position mark P10 positioned above the opening H. Two marks are arranged so as to be sandwiched between position marks P1 as separation marks. The arrangement of the colors (six colors) of the color code mark P3 changes variously. Therefore, in the reference color mark extraction step (S150), the position mark P10 located above the aperture H is counted as the first from the color data collected by scanning the ring, and the second, fourth, and ninth positions are counted clockwise. Are sequentially extracted. In the reference color mark storage step (S155), the color data of each reference color mark P2 extracted sequentially is stored in the reference color mark storage unit 83. Further, in the color code mark extraction step (S160), the position mark P10 located above the aperture H is counted first from the color data collected by scanning the ring and counted 6, 7, 11, The 12th, 14th, and 15th color data are sequentially extracted. In the color code mark storage step (S165), the color data of each color code mark P3 extracted sequentially is stored in the color code mark storage unit 84. The scan route is collated with the converted position data (for example, affine transformation). If the color data collected by scanning on the ring matches the design data, the collected color data is the color of the reference color mark P2, color code mark P3, and position mark P1 of the color code targets TA1 to TA3. It can be determined that the data. The determination is made, for example, after the color code is extracted in the color code mark extraction step (S160). Further, the hue distance of the reference color of the reference color mark P2 is compared and checked. Further, the hue distances of the six colors of the color code mark P3 are compared and checked. In this way, it is checked whether or not the color code targets TA1 to TA3 (ring color code targets) to be obtained from these color schemes. If they are different, the process returns to (S230) to check another triangle. If it is determined that the color code targets TA1 to TA3 are to be obtained, the process proceeds.

  Next, the color code is determined (S260). This step corresponds to the color code discrimination step (S170). A code is read from the color scheme of the color code mark P3 to determine the color code. The color code discriminating unit 75 counts the color data (hue, hue) of the sixth, seventh, eleventh, twelfth, fourteenth and fifteenth color code marks P3 counting clockwise from the position mark P10 positioned above the opening H as the first. Saturation, lightness) is counted clockwise with the position mark P10 positioned above the aperture H as the first color data (hue, saturation, lightness) of the second, fourth, and ninth reference color marks P2. In comparison, it is determined whether the color of each color code mark P3 is red, yellow, green, cyan, blue, or magenta. At this time, if the condition that the number of color code marks P3 is equal to the number of code colors is imposed, all code colors are used for the color code mark P3. Therefore, not only the comparison with the reference color mark P2, but also the color code. Reliability can be improved by relatively comparing colors between the marks P3. The color of the reference color mark P2 can be used for correcting the color of the measurement object 2 in addition to correcting the color of the color code mark P3. Also, the color code determination unit 75 converts the color data into a color code using the color-code correspondence table and the color code target correspondence table. That is, the color mark data of the sixth, seventh, eleventh, twelfth, fourteenth and fifteenth color code mark P3 counted clockwise from the position mark P10 positioned above the opening H as the first color arrangement data in this arrangement order. The color array data is converted into a color code. Next, labeling is performed (S270). This step corresponds to the color code storing step (S180). That is, the determined color code is stored in the color code storage unit 85 in association with the reference position (center) C0 of the color code targets TA1 to TA3 (S270). Thereby, the color code is attached to the reference position of the color code targets TA1 to TA3 as a label. If other triangle combinations (candidates for T1 and T2) to be searched remain, the process returns to (S230), and these combinations are similarly processed. This substantially searches for the other color code targets TA1 to TA3. If not, complete the process.

  As described above, according to the present embodiment, when the hole is provided at the center of the color code target, it is easy to measure the reference position of the target, and the color code mark can be easily detected and the color code can be easily distinguished. Can provide a target. In addition, a color code determination apparatus and a color code determination method suitable for determining the color code of the color code target can be provided.

FIG. 12 shows an example of the color code target TA4 in the second embodiment. In Example 1, there was one ring (ring), but Example 2 shows an example in which the ring is double. The inner ring is the same as in Example 1, but another ring is provided on the outer side. In the outer ring, the arrangement of the reference color mark P2 and the color code mark P3 in the circumferential direction is the same as that of the inner ring, and the color arrangement order of the color code mark P3 is changed. Further, the position mark P1 is changed to a black separation mark P4. Since the circular ring is double, and the number of color code marks P3 is doubled (n = 12 units), the number of possible identification codes is increased with 6 ^12. In addition, the reference position C0 and the opening H are the same as those in the first embodiment, and when the opening is provided at the center of the color code target, it is easy to measure the reference position of the target. It is possible to provide a color code target that can be easily discriminated.

  FIG. 13 shows an example of the color code target TA5 in the third embodiment. In the second embodiment, the position mark P1 is provided on the inner ring, but in the third embodiment, the position mark P1 is provided across the inner and outer rings. As a result, the position mark P1 can be enlarged and easily detected. In addition, the arrangement of the position mark P1, the reference color mark P2, and the color code mark P3 is the same as in Example 2, and when the hole is provided at the center of the color code target, the measurement of the reference position of the target is easy. A color code target that can easily detect a color code mark and determine a color code can be provided.

  FIG. 14 shows an example of the color code target TA6 in the fourth embodiment. Compared to the second embodiment, two circular rings are separated by a black region. Thereby, two circular rings can be clearly distinguished. Therefore, it is possible to reduce errors in the circular scan. In addition, the arrangement of the position mark P1, the reference color mark P2, the color code mark P3, and the delimiter mark P4 is the same as that in the second embodiment, and when the hole is provided at the center of the color code target, the reference position of the target is measured. It is easy to provide a color code target that can easily detect a color code mark and distinguish a color code.

  FIG. 15 shows an example of the color code target TA7 in the fifth embodiment. In the fourth embodiment, the position mark P1 is provided on the inner ring, but in the fifth embodiment, the position mark P1 is provided across the inner and outer rings. As a result, the position mark P1 can be enlarged and easily detected. In addition, the arrangement of the position mark P1, the reference color mark P2, and the color code mark P3 is the same as in Example 2, and when the hole is provided at the center of the color code target, the measurement of the reference position of the target is easy. A color code target that can easily detect a color code mark and determine a color code can be provided.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it is obvious that various modifications can be made to the embodiments without departing from the spirit of the present invention. .

  For example, in the above embodiments, the example in which the marks are annularly arranged along the circumference centered on the reference position has been described. However, the marks may be annularly arranged along the outer periphery of the regular polygon. Further, an example in which the reference color is 3 colors and the color code color is 6 has been described, but it is sufficient that the reference color is 1 color or more and the color code color is 2 colors or more, and the number of reference color marks is 1 or more. The number of color code marks may be one or more. When the number of color code marks is 1, the reference color mark and the color code mark can be distinguished from each other by changing the circumferential or radial width. The greater the number of color code colors, the greater the number of codes that can be used. The smaller the number of color code colors, the easier it is to discriminate color differences, and the processing can be simplified. The reference number of colors typically uses three primary colors of light, but can be changed according to the number of color code colors. In the above embodiment, an example in which the number of mark rings is single or double has been described, but it may be triple or more. The greater the number of rings, the greater the number of codes that can be used, and the smaller the number, the simpler the configuration and the easier the processing. Further, when the mark ring is double, the reference color mark may be arranged in the inner ring and the color code mark may be arranged in the outer ring for distinction. In the above embodiment, the opening H is described as being inscribed in the mark ring. However, the color code target may have an inner frame region between the mark ring and the opening. The outer frame region may be provided outside the mark ring. In the above embodiments, the center of the opening is the reference position and coincides with the center of the color code target. However, it may be decentered to some extent from the center of the color code target. In the above embodiment, an example in which two triangles with congruent arrangement of position marks can be extracted has been described. However, two inverted symmetrical triangles may be extracted. Further, although an example in which two triangles corresponding to a plurality of color code targets in the measurement range are extracted has been described, two triangles corresponding to each target may be extracted. In addition, the color code identification device may have a simplified configuration by omitting, for example, the input unit, the output unit, the starting point calculation unit, the corresponding point search unit, the orientation unit, and the like. As for the color code identification method, the order of the steps can be changed. For example, the collection of color data from the mark ring may be performed before the calculation of the starting point. After the mark arrangement detection step, the mark extraction step You may collect again. In the above embodiment, the example in which the determination whether the color data collected by scanning on the ring matches the design data is performed in the color code mark extraction process, but in the mark arrangement detection process. Color data may be collected and performed. Either the reference color mark extraction step or the color code mark extraction step may be performed first. In addition, the outer shape of the mark (4, 6, octagonal shape, etc.), the number of marks sandwiched between the separator marks, the number of color code colors, the number of color code marks, and the like can be appropriately changed.

  The present invention is used for various three-dimensional measurements. In particular, it is used for three-dimensional measurement in which multi-point measurement is performed by providing an aperture through which a prober or the like is passed.

DESCRIPTION OF SYMBOLS 1 Color code discrimination | determination apparatus 2 Measuring object 3 Image pick-up part 4 Input / output part 5 Feature extraction part 6 Three-dimensional position measurement part 7 Image processing part 8 Storage part 9 Control part 10 PC
31 Target image acquisition unit 41 Display unit 42 Output unit 43 Input unit 51 Position mark detection unit 52 Feature point extraction unit 61 Corresponding point search unit 62 Orientation unit 63 Reference position calculation unit 64 Three-dimensional position calculation unit 71 Origin calculation unit 72 Mark arrangement Detection unit 73 Reference color mark extraction unit 74 Color code mark extraction unit 75 Color code discrimination unit 81 Captured image storage unit 82 Three-dimensional position storage unit 83 Reference color mark storage unit 84 Color code mark storage unit 85 Color code storage unit 200 Retro target 204 Inner circle portion 206 Outer circle portion C0 Reference position H Opening hole P0 Reference position marks P1, P10 Position marks (separation marks)
P2 Standard color mark P3 Color code mark P4 Separation mark To Threshold value T1 First triangle T2 Second triangle TA, TA1-7 Color code target

Claims (14)

A position mark portion comprising a position mark for indicating a measurement position;
A reference color portion comprising reference color marks with colors used as color references;
A color code portion composed of a color code mark provided with a color for identifying the color code target;
Provided in-plane with a mark delimiter part comprising delimitation marks for delimiting between the reference color mark and the color code mark, between the reference color marks or between the color code marks;
The position mark, the reference color mark, and the color code mark are arranged in an annular shape along a circumference or a regular polygonal periphery centered on the reference position;
The reference position is provided with an aperture;
The delimiter marks are arranged to sandwich a first predetermined number of the reference color marks and a second predetermined number of the color code marks;
Color code target. The position mark also serves as the separator;
The color code target according to claim 1. The first predetermined number is 1 and the second predetermined number is a constant greater than or equal to 2;
The color code target according to claim 1 or 2. The number of marks of the color code mark matches the number of colors used for the color code, and the colors of the color code marks constituting the color code portion are all different;
The color code target according to any one of claims 1 to 3. The reference color mark and the color code mark are arranged in a predetermined positional relationship with respect to the reference position;
The color code target according to any one of claims 1 to 4. The position marks are composed of at least six pieces, and are arranged so that two congruent or inverted symmetrical triangles can be extracted from triangles formed by connecting the centers of the position marks;
The color code target according to any one of claims 1 to 5. A single ring of marks arranged in an annular shape along the circumference of the circumference or regular polygon;
The color code target according to any one of claims 1 to 6. A plurality of mark rings arranged annularly along the circumference or the outer periphery of the regular polygon, each of the mark rings being centered on the reference position;
The color code target according to any one of claims 1 to 6. The position mark, the reference color mark and the color code mark arranged on one ring of the marks are unified in the same shape and size;
The color code target according to claim 7 or 8. A set of color code targets configured by combining a plurality of color code targets according to any one of claims 1 to 9;
In each color code target, the position mark, the reference color mark, and the color code mark are arranged at the same position on the ring of the mark, the color arrangement of the reference color mark is the same, and the color code mark Configured to have all different color arrangements;
A set of color code targets. A target image acquisition unit that acquires an image of the color code target according to claim 1 from at least two different directions;
A position mark detection unit that sequentially detects the position marks from images of color code targets acquired from at least two different directions by the target image acquisition unit;
A reference position calculation unit for obtaining the reference position of the color code target from the arrangement of position marks sequentially detected by the position mark detection unit;
A mark arrangement detection unit that sequentially detects marks arranged in an annular shape along the circumference or the outer periphery of a regular polygon centered on the reference position obtained by the reference position calculation unit;
A reference color mark extraction unit that sequentially extracts the reference color marks from a ring of marks detected by the mark arrangement detection unit;
A color code mark extraction unit that sequentially extracts the color code marks from a ring of marks detected by the mark arrangement detection unit;
The color of each reference color mark extracted by the reference color mark extraction unit is compared with the color of each color code mark extracted by the color code mark extraction unit, and the color code is determined from the color arrangement of the color code mark. A color code discrimination unit for discrimination;
A color code storage unit that stores the reference position calculated by the reference position calculation unit and the color code determined by the color code determination unit in association with each other;
Color code discrimination device. A starting point calculation unit for obtaining a starting point for detecting the annularly arranged marks by the mark arrangement detecting unit based on the arrangement of the position marks sequentially detected by the position mark detecting unit;
The mark arrangement detecting unit sequentially detects the marks from the starting points obtained by the starting point calculating unit;
The color code discrimination device according to claim 11. A target image acquisition step of acquiring an image of the color code target according to claim 1 from at least two different directions;
A position mark detection step of sequentially detecting the position marks from images of color code targets acquired from at least two different directions in the target image acquisition step;
A reference position calculation step for obtaining the reference position of the color code target from the position mark arrangement sequentially detected in the position mark detection step;
A mark arrangement detecting step of sequentially detecting marks arranged in a ring shape along a circumference or a regular polygon outer periphery centered on the reference position obtained in the reference position calculating step;
A reference color mark extraction step of sequentially extracting each of the reference color marks from the ring of marks detected in the mark arrangement detection step;
A color code mark extraction step of sequentially extracting the color code marks from a ring of marks detected in the mark arrangement detection step;
The color of each reference color mark extracted in the reference color mark extraction step is compared with the color of each color code mark extracted in the color code mark extraction step, and the color code is determined based on the color arrangement of the color code mark. A color code discrimination process for discrimination;
A color code storage step for storing the reference position obtained in the reference position calculation step and the color code determined in the color code determination step in association with each other;
Color code discrimination method. A starting point calculating step for obtaining a starting point for detecting the annularly arranged marks in the mark arrangement detecting step based on the arrangement of the position marks sequentially detected in the position mark detecting step;
The mark arrangement detecting step sequentially detects the marks from the starting point obtained in the starting point calculating step;
The color code discrimination method according to claim 13.

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