JP2006293484A - Information processing method, information processor, computer program and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for facilitating the input of marker information. <P>SOLUTION: This information processing method is characterized to comprise a display step for displaying an interface to input the vertex coordinates of an index and a derivation step for deriving index information to be used for plotting a CG image based on the vertex coordinates inputted by the interface. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for inputting the position and orientation of a marker in a three-dimensional coordinate space.

  Conventionally, MR (Mixed Reality), AR (Augmented Reality), Augmented Reality, Augmented Reality, Augmented Reality, etc., aiming to seamlessly merge the real world and the virtual world in real time Technology is known. In an image processing system that provides MR or the like, for example, a process of superimposing and displaying a virtual space CG (Computer Graphics) image on a real space image taken by an imaging device such as a video camera is performed.

  In such a system, it is required to perform alignment between the real space and the virtual space in order to draw a CG image at an appropriate position. Therefore, an index having a regular polygon shape (hereinafter referred to as a marker) is installed in the real space, and the position of the imaging device is measured from the position and orientation of the marker included in the image captured by the imaging device. The system is known.

In a system that measures the position of an imaging device from the position and orientation of a marker included in a captured image, it is necessary to input marker information relating to the position and orientation of the marker in advance to the system. Here, the marker information that needs to be input to the system in advance is as follows.
(A) The world coordinate position of the center of gravity of the marker (p _x , p _y , p _z )
(B) Angle of rotation of marker relative to reference direction (θ)
(C) Marker rotation axis vector R (r _x , r _y , r _z )
(D) Length (size) of one side of the marker (sz)
In the above, (a) is a parameter for determining the position of the marker, and (b) and (c) are parameters for determining the posture of the marker. The marker information is not limited to this, and any parameter that describes the position and orientation of the marker may be used. In the image processing system, the marker information is used for appropriate drawing of the CG image.

  FIG. 1 is a diagram exemplarily showing a marker having an equilateral triangle shape. In FIG. 1, reference numeral 101 denotes a marker having an equilateral triangle shape, and its outer edge is filled with a predetermined color (for example, black). Reference numeral 102 denotes a point indicating the center (center of gravity) of the marker 101, which is colored with a predetermined color (for example, black) so that the position of the center of gravity 102 can be seen from the appearance. As shown in FIG. 1, the length of one side of the marker is the size sz.

In the measurement system using the marker, a world coordinate system 201 is defined as illustrated in FIG. The world coordinate system 201 is a three-dimensional coordinate system configured with a predetermined position as an origin. The marker position is determined by the coordinates (p _x , p _y , p _z ) of the center of gravity 102 in the world coordinate system 201.

  The posture of the marker 101 is described as a marker parallel to the xy plane rotated by a rotation angle θ along the rotation axis vector R203.

In the conventional system, the user has to specify the marker information such as the world coordinates of the center of the marker, the rotation axis and rotation angle indicating the orientation, the size of the index, etc. for each of the markers installed in the measurement system. This applies not only to triangular markers as illustrated in FIGS. 1 and 2 but also to n (≧ 4) square markers such as quadrangular markers, pentagonal markers, and the like.
D. Kotake, S. Uchiyama, and H. Yamamoto: "A marker calibration method utilizing a priori knowledge on marker arrangement," Proc. 3rd IEEE / ACM Int'l Symp. On Mixed and Augmented Reality (ISMAR 2004), pp. 89-98, November 2004.

  However, manual determination of marker information such as the world coordinate position of the center of gravity of the marker, the rotation angle with respect to the reference direction, the rotation axis vector, etc. is cumbersome and inconvenient. For example, as shown in FIG. 3, it is complicated to manually obtain the marker information of the marker 302 stretched on the oblique plane 301 that is parallel or not orthogonal to any of the xy plane, yz plane, and zx plane. Takes time and effort.

  The present invention has been made in view of the above problems, and an object thereof is to provide a technique that facilitates the input of marker information.

  According to the present invention, a display process for displaying an interface for inputting vertex coordinates of an index on a display device, and derivation for deriving index information used for drawing a CG image based on the vertex coordinates input from the interface. There is provided an information processing method comprising the steps.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which makes easy the input of marker information can be provided.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. However, the constituent elements described in this embodiment are merely examples, and are not intended to limit the scope of the present invention only to them.

  In the present embodiment, a configuration in which it is easy to input marker information (information on the position and orientation of the marker) of a square marker (index) installed in the world coordinate system will be described. In the image processing system, the marker information is used for appropriate drawing of the CG image.

  The configuration of the present embodiment is a marker information derivation tool (hereinafter referred to as a tool) that derives marker information based on information input by a user and generates a marker file for a system that detects a square marker from an image. Provided). This tool is realized as software operating on an information processing apparatus (computer) such as a personal computer (PC), a workstation (WS), or a personal digital assistant (PDA). In this embodiment, a configuration using a square marker is described, but this can be easily extended to a predetermined polygonal marker. The tool in the present embodiment may be realized by hardware having equivalent functions.

[Configuration of information processing device]
First, an outline of an information processing apparatus corresponding to the present embodiment will be described. FIG. 15 is a block diagram illustrating a device configuration of the information processing apparatus corresponding to the present embodiment.

  In FIG. 15, reference numeral 1600 denotes a CPU which executes an application program, an operating system (OS), a control program, and the like stored in a hard disk device (hereinafter referred to as HD) 1605 which will be described later, and is necessary for executing the program in the RAM 1602 Control to temporarily store information, files, etc.

  Reference numeral 1601 denotes a ROM that stores therein various data such as a program such as a basic I / O program, font data used in document processing, and template data. A RAM 1602 temporarily stores various data, and functions as a main memory, a work area, and the like of the CPU 1600.

  Reference numeral 1603 denotes an external storage drive for realizing access to a recording medium, and a program or the like stored in a medium (recording medium) 1604 can be loaded into the computer system. The medium 1604 is arbitrary, for example, a flexible disk (FD), a CD-ROM, a CD-R, a CD-RW, a PC card, a DVD, an IC memory card, an MO, a memory stick, and the like.

  Reference numeral 1605 denotes an external storage device, which uses an HD that functions as a large-capacity memory in this embodiment. The HD 1605 stores application programs, OS, control programs, related programs, and the like.

  Reference numeral 1606 denotes an instruction input device, which corresponds to a keyboard, a pointing device (such as a mouse), a touch panel, or the like. Using the instruction input device 1606, the user instructs the information processing device to input a command or the like for controlling the device.

  Reference numeral 1607 denotes a display for displaying a command input from the instruction input device 1606, a response output of the information processing device for the command, and the like.

  Reference numeral 1609 denotes a system bus, which controls the flow of data in the information processing apparatus. Reference numeral 1608 denotes an interface (hereinafter referred to as I / F), which exchanges data with an external device via the I / F 1608.

  In addition, it can also be comprised as an alternative of a hardware apparatus with the software which implement | achieves a function equivalent to the above each apparatus.

  In this embodiment, an example is shown in which the program and related data according to this embodiment are directly loaded from the medium 1604 into the RAM 1602 and executed. However, every time the program according to this embodiment is operated, the program is already executed. May be loaded into the RAM 1602 from the HD 1605 installed. It is also possible to record the program according to the present embodiment in the ROM 1601, configure it as a part of the memory map, and execute it directly by the CPU 1600.

  In the information processing apparatus according to the present embodiment, Windows (registered trademark) is installed as an operating system, and Windows (registered trademark) executes basic control. Note that an information processing apparatus in which an operating system other than Windows (registered trademark) is installed may be used.

[Marker configuration]
A quadrangular marker (hereinafter referred to as a square marker) used in the present embodiment is illustrated in FIG. As shown in FIG. 4, the square marker is configured such that a reference point 402 of a predetermined color (for example, black) is in a square of an edge 401 of a predetermined color (for example, black).

  The tool in the present embodiment has a position and orientation of the square marker, that is, a posture obtained by rotating the square marker parallel to the xy plane with respect to which axis and how much the square marker in the world coordinate system of the square marker. The purpose is to obtain information such as the length of one side of the square marker.

FIGS. 5A and 5B are diagrams exemplarily showing square markers installed in the world coordinate system. In the square marker 501 shown in FIGS. 5A and 5B, the length of one side is sz, and the barycentric coordinates are (p _x , p _y , p _z ). Further, as shown in FIG. 5B, the posture of the marker is obtained by rotating a marker parallel to the xy plane by a rotation angle θ with respect to the rotation axis vector R = (r _x , r _y , r _z ) 502. Is described as

FIG. 6 illustrates a marker file describing the position and orientation of the square marker. In the marker file, one marker is described in the following format.
SquareMarker <identifier> {
Position (p _x , p _y , p _z )
Orientation (r _x , r _y , r _z ) θ
Size sz
}
Therefore, for example, 601 in FIG. 6 is a description of the marker with the identifier sq1, the barycentric coordinates are (0, 100, 200), the rotation axis vector R is (1, 0, 0), and the rotation axis vector R It shows that the rotation angle is 90 ° and the length of one side is 50. The tool in this embodiment outputs such a marker file.

  Thus, in this embodiment, position information and posture information are set as marker information.

[Marker information derivation process]
Next, marker information derivation processing executed by the tool will be described. FIG. 16 is a flowchart showing the overall flow of the marker information derivation process.

  In step S301, the tool displays a marker setting screen (square index setting screen) on the display 1607. FIG. 7 is a diagram exemplarily showing the marker setting screen.

  In FIG. 7, reference numeral 701 denotes a user interface of a tool that executes processing for a square index, that is, marker information of a square marker, and accepts an instruction input such as calling a marker file or inputting marker information. Reference numeral 702 denotes an input area for receiving an input of an index name, that is, a marker name. Reference numeral 703 denotes an input area for inputting a marker position, that is, a barycentric coordinate of the marker. 704 is an input area for the rotation axis vector of the marker, 705 is an input area for the rotation angle, and 706 is an input area for the size (length of one side) of the marker.

  Reference numeral 707 denotes a vertex designation button that is selected when the marker information of 703 to 706 is derived by inputting the coordinates of each vertex of the marker. Reference numeral 708 denotes a plane designation button 708 that is selected when deriving the marker information 703 to 706 by inputting information about the plane on which the marker is installed.

  Reference numeral 709 denotes a file button which is selected when reading, writing, saving, etc. of a marker file to be edited. Processing such as reading and writing of the marker file is executed based on the control of the operating system. Reference numeral 710 denotes an edit button, which is selected when an editing process such as addition or deletion of a marker to the marker file is executed.

  FIG. 7 shows a screen immediately after an instruction to add marker information from the edit menu, that is, to add marker information to the marker file to be edited. As shown in FIG. 7, when an instruction to add marker information is input, the tool calls the specified marker information, sets the marker information of the marker specified in 702 to 706, and displays it. In the example of FIG. 7, the initial value of the marker name is “NewMarker”, and the marker information of the added square marker is created with the name “NewMarker” on the tree view on the left side of the window.

  The tool in this embodiment can directly input information 703 to 706, that is, marker information such as the position of the center of gravity of the marker, the rotation axis vector, and the rotation angle. However, in view of the derivation thereof. Then, a process of deriving marker information based on input of coordinates of each vertex of the marker or input of information on a plane on which the marker is installed is performed.

  If the vertex designation button 707 is selected in FIG. 7, that is, if the input by vertex designation is selected in step S302 (YES in step S302), the process proceeds to step S304. In step S304, a derivation process by vertex designation described later is executed, and the process ends.

  If the plane designation button 708 is selected in FIG. 7, that is, if the input by plane designation is selected in step S303 (YES in step S303), the process proceeds to step S304. In step S304, a derivation process based on plane designation described later is executed, and the process ends.

[Derivation processing by vertex specification]
Next, the derivation process by apex designation will be described. In this process, each vertex of the marker is received as input, and marker information is derived. FIG. 10 is a flowchart showing the flow of derivation processing by apex designation.

  First, in step S101, the vertex designation input screen is displayed on the display 1607. FIG. 8 is a diagram showing an example of the apex designation input screen. In FIG. 8, reference numeral 801 denotes an example of a vertex designation input screen. Reference numeral 803 denotes a coordinate input area for receiving coordinate input of each vertex of the marker. Reference numeral 802 denotes a display area that displays a schematic diagram including the positional relationship of each vertex of the marker together with the serial number of each vertex based on the coordinates of each vertex of the marker input to the coordinate input area 803.

  In this embodiment, the vertex of the index having a planar rectangular shape is used as the feature point of the marker (index).

  The tool in the present embodiment assumes that the coordinates of each vertex of the marker 501 are input clockwise or counterclockwise. Therefore, the tool displays a schematic diagram of the marker 501 in which the number is assigned to each vertex in the display area. However, it is assumed that the serial numbers attached to the vertices of the markers 501 in the schematic diagram are assigned clockwise or counterclockwise. The user inputs the coordinates of the vertices to the coordinate input area 803 in the order of the serial numbers assigned to the vertices of the markers displayed in the display area 802. Thus, the user can input the coordinates of each vertex in association with the serial number of each vertex, and the operation is easy.

  In the present embodiment, in the setting of the square marker, the apex is designated counterclockwise from the opposite corner of the reference point 402. According to the present embodiment, the direction of the square marker can also be used as marker information by designating from the opposite side of the reference point 402.

  Thus, in the present embodiment, the positions of the four feature points are identified (specified) from the feature points whose positions are determined based on the reference points 402 (the corners on the opposite side of the reference points 402).

  The schematic diagram of the marker 501 is visually presented to the user so that the user can easily recognize the position of the feature point. Furthermore, since the normal vector is added on the schematic diagram, the orientation of the marker 501 is visually presented to the user.

  According to this embodiment, it is possible to reduce the user's mistaken input of feature points.

  Reference numeral 804 denotes an OK button, which is selected by the user when the coordinate input is completed. A cancel button 805 is selected by the user when canceling the coordinate input. When the OK button 804 is selected, the tool determines that the coordinates of the input vertices have been determined, and proceeds to step S102. In the processing after S102, the tool calculates the position of the center of gravity of the marker, the rotation axis vector indicating the posture of the marker, the rotation angle, and the size of the marker from the input information of the four vertices. Assign a value to a field.

The coordinates of the four vertices input by the user in step S101 must satisfy the following conditions.
(A) The four vertices are on the same plane. (B) The four vertices form a square on the above plane. However, since there is a measurement error in actual operation, the tool should be adjusted to meet these conditions. Calculate the value.

In step S102, the tool obtains the barycentric coordinates P _m of the markers from the four vertices of coordinates inputted. If the coordinates of the four input vertices are P _i (0 ≦ i <4),
P _m = (P ₀ + P ₁ + P ₂ + P ₃ ) / 4
In it can be determined barycentric coordinates P _m of the markers. Here, the addition / subtraction / multiplication / division of the vertex coordinates P _i means the addition / subtraction / multiplication / division of each coordinate component. The same shall apply hereinafter unless otherwise specified.

  Next, in step S103, a normal vector of a plane passing through the four vertices is obtained. In order to round the measurement error, the tool in the present embodiment obtains a vector orthogonal to four vectors connecting four vertices, and sets the average as the normal vector of the marker.

The coordinates of the four vertices are P _i (0 ≦ i <4), and a vector V created therefrom is defined as follows.

V _i = P _{i + 1} −P _i (when 0 ≦ i <3)
V ₃ = P ₀ −P ₃
At this time, a vector N _i orthogonal to V _i and V _{i + 1} is given by the following equation.

N _i = V _{i + 1} × V _i (when 0 ≦ i <3, x indicates an outer product)
N ₃ = V ₀ × V ₃
FIG. 11 is a diagram schematically showing the positional relationship between P _i , V _i , and N _i . In the present embodiment, an average of N _{0 to} N ₃ is used as a marker normal vector N _m . That is,
N _m = (N ₀ + N ₁ + N ₂ + N ₃ ) / 4
It is.

  In this embodiment, since the vertex coordinates of the marker are input counterclockwise, the normal line can be determined as illustrated in 802 by the calculation described above. If the vertex of the marker is input in the clockwise direction, the normal vector must be obtained by inverting the vector obtained by the calculation described above.

Next, in step S104, a rotation axis vector and a rotation angle are obtained. The reference marker posture is an orientation that stands upright parallel to the xy plane and has a reference point 402 on the upper right. Considering the correspondence between the marker in the reference posture and the side of the marker indicated by the input coordinates, (sz, 0, 0) and V ₀ correspond to (0, sz, 0) and −V ₃ . However, V ₀ and −V ₃ are not necessarily orthogonal to each other. Therefore, the outer product of V ₀ and −V ₃ is obtained once, and the outer product of the result and V ₀ is obtained to find −V ₃ ′ orthogonal to V ₀ .

When (sz, 0, 0), (0, sz, 0), V ₀ , and −V ₃ ′ are normalized to unit matrices, the x-axis and y-axis unit matrices are expressed as V ₀ / | V ₀ |, It can be seen that it corresponds to −V ₃ ′ / | −V ₃ ′ |. x-axis, the matrix of the _{y-axis, V 0 / | V 0 |} , -V 3 '/ | -V 3' | a rotation matrix R _M for converting the determined rotation axis vector from the rotation matrix R _M, the rotation If the angle is obtained, the posture of the marker from the reference posture can be obtained. And obtaining the rotation matrix R _M, the rotation axis vector from a rotation matrix R _M, Determination of the rotation angles are not described here as being known.

Next, in step S105, the marker size sz is obtained. This can be obtained by taking the average of the lengths of V _i obtained previously.

sz = (| V ₀ | + | V ₁ | + | V ₂ | + | V ₃ |) / 4
After the above processing, the tool controls the display of the marker information derived in steps S102 to S105 on 702 to 706 of the user interface 701 illustrated in FIG. 7, and ends the processing.

Through the above processing, the user inputs the coordinates of each vertex of the marker that can be easily measured, whereby the barycentric coordinates P _{m of} the marker, the rotation axis vector R and the rotation angle θ for indicating the posture of the marker, and the marker size sz. Can be requested. In addition, since the tool performs the process of averaging the measured values as appropriate when calculating the barycentric coordinates, normal vector, and size, even if the measured values include errors, the errors are corrected and A high value can be obtained. Moreover, since the tool inputs the coordinates of the vertexes in order along the outer edge of the marker, it is easy to input the vertex coordinates.

  Note that the above method can be applied regardless of the regular polygon of the marker. That is, in step S102, the center-of-gravity coordinates can be obtained by obtaining the average of the coordinates of each vertex of the marker. In step S103, the normal vector of the marker can be obtained by obtaining the average value of the outer products of the vectors of adjacent sides. In step S104, the rotation angle and the rotation axis vector can be obtained from the reference direction vector and the normal vector in the same manner as described above. In step S105, the size can be obtained by obtaining the average length of each knitting. In addition, the tool averages the measured values as appropriate when calculating the barycentric coordinates, normal vector, and size, so that even if the measured values contain errors, a highly reliable value is obtained. The same is true for the point that

[Derivation process by plane specification]
Next, the derivation process by plane designation will be described. In this process, the coordinates of three points on the plane including the marker and the coordinates of the marker in the coordinate system on the plane are received as inputs, and the marker information is derived. FIG. 12 is a flowchart showing a flow of derivation processing by plane designation.

  First, in step S201, display control of the plane designation input screen is performed on the display 1607. FIG. 9 shows an example of the plane designation input screen. In FIG. 9, reference numeral 901 is an example of a plane designation input screen.

  Reference numeral 903 denotes a coordinate input area for receiving coordinate input of three points (vertices 1, 2 and 3) on the plane including the marker. Reference numeral 902 denotes a display area that schematically displays the positional relationship of each point together with a serial number based on the coordinates of the three points input to the coordinate input area 903. The three vertices (vertices 1, 2, and 3) have the following meanings.

First vertex: Origin of the plane containing the marker Second vertex: Vertex on the x-axis of the plane containing the marker Third vertex: Vertex on the plane containing the marker That is, the first and second vertices In the coordinate system on the plane including the marker, the origin and the x axis are defined, and the y axis is defined from the third vertex. Here, the positive / negative direction of the y-axis is defined as positive when the plane including the marker is divided by the x-axis, for example. Hereinafter, for simplification of description, when the plane including the marker is divided by the x-axis, the direction including the third vertex is defined as the positive y-axis. The user can input the vertex coordinates associated with the serial number of each vertex displayed in the display area 902, and the operation is easy.

  Reference numeral 905 denotes a coordinate input area in which the coordinates of the two vertices of the marker are input in a coordinate system defined from values input to the coordinate input area 903. It is assumed that the coordinates of two points adjacent to each other are input.

  Reference numeral 904 denotes a display area that schematically displays the positional relationship between the vertices of the marker. Here, in order to facilitate the input of coordinates, for example, a vertex for inputting coordinates may be designated based on the position of the reference point 402. In the example of FIG. 9, the vertex farthest from the reference point (vertex A) and the vertex (vertex B) adjacent to the vertex A in the counterclockwise direction are designated.

  Reference numeral 906 denotes an OK button which is selected by the user when the coordinate input is completed. A cancel button 907 is selected by the user when canceling the coordinate input. When the OK button 906 is selected, the tool determines that the coordinates of the input vertices have been determined, and proceeds to step S202. In the processing after S202, the tool calculates the position of the center of gravity of the marker, the rotation axis vector indicating the posture of the marker, the rotation angle, and the size of the marker from the input information, and sets values in the fields of FIG. substitute.

In step S202, the tool obtains a normal vector of a plane including the marker from the coordinates of the vertices 1 to 3 input to the coordinate input area 903. If the positions of vertices 1, 2, and 3 that specify a plane are P ₀ , P ₁ , and P ₂ , respectively, the normal line N _p of the plane is
_{N p = (P 1 -P 0} ) × (P 2 -P 0)
Can be obtained.

Next, in step S203, the barycentric coordinates of the marker on the plane base determined from the vertices 1, 2, and 3 are obtained. As described above, the coordinates of the vertices A and B adjacent in the counterclockwise direction are input to the coordinate input area 905. Therefore, as shown in FIG. 13, we obtain the coordinates of the vertices Q adjacent in the counterclockwise direction of the vertex B, obtains the coordinates of the marker of the center of gravity M _f by calculating the coordinates of the midpoint of AQ. The coordinates of Q are obtained by adding a vector obtained by rotating a vector AB (represented as B-A) by 90 ° to the coordinates of B. For this reason, the coordinates of Q and _Mf are given by the following equations.

When the marker is a regular n-gon, the Q coordinate is obtained by adding a vector obtained by rotating the vector AB (represented as B-A) by (360 / n) ° to the B coordinate. Therefore, in the case of a regular n-gon, 90 ° in Equation 1 is (360 / n) °. Further, for example, the coordinates of M _f may be obtained as the intersection of the AB perpendicular bisector and the BQ perpendicular bisector.

Next, in step S204, a process of converting the barycentric coordinates of the marker in the plane coordinate system obtained in step S203 into coordinates in the world coordinate system is performed. Therefore, first, the unit vectors E _x and E _y in the world coordinate system of the direction vectors of the x axis and the y axis in the plane coordinate system are obtained. Obviously, E _x is given by:

E _x = P ₁ −P ₀ / | P ₁ −P ₀ |
Further, when the plane including the marker is divided by the x-axis, the direction including the third vertex (P ₂ ) is defined as the positive y-axis, so that E _y is a modulus as shown in FIG. perpendicular to the line vector N _p.

Therefore, E _y is given by the following equation obtained by the unit vector of the cross product of N _p and E _x.

E _y = N _p × E _x / | N _p × E _x |
The tool determines E _x and E _y as described above. In this case, determined at step S204, the barycentric coordinates M _f of the marker in the plane coordinate system (m _x, m _y) When, the coordinates P _m of the markers in the world coordinates,
P _m = mx _x E _x + my _y E _y + P ₀
It becomes. The marker size sz is sz = | AB | as apparent from FIG.
It is.

Next, in step S205, the rotation axis vector and rotation angle of the marker are obtained. The reference marker posture is an orientation that stands upright parallel to the xy plane and has a reference point 402 on the upper right. Considering the correspondence between the marker in the reference posture and the side of the marker indicated by the input coordinates, (sz, 0, 0) and the vector AB in FIG. 13 correspond to (0, sz, 0) and the vector BQ. To do.
Vector AB, to fix the vector BQ world coordinate system, each of x, may be multiplied by the y component E _x, the E _y. Vector AB in the so obtained world coordinate system, BQ each M _x, and M _y.

(Sz, 0,0), (0 , sz, 0), M x, when normalized to the respective unit matrix of M _y, x-axis, the matrix of the _{y-axis, M x / | M x |} , M y It can be seen that it corresponds to / | M _y |. x-axis, the matrix of the _{y-axis, M x / | M x |} , M y / | M y | determine the rotation matrix R _M which converts the rotation axis vector from the rotation matrix R _M, by obtaining the rotation angle The posture of the marker from the reference posture can be obtained. And obtaining the rotation matrix R _M, the rotation axis vector from a rotation matrix R _M, Determination of the rotation angles are not described here as being known.

Through the above processing, the center-of-gravity coordinates P _{m of} the marker, the rotation axis vector R and the rotation angle θ for indicating the posture of the marker, and the marker size sz can be obtained.

  After the above processing, the tool controls the display of the marker information derived in steps S202 to S205 on 702 to 706 of the user interface 701 illustrated in FIG. 7, and ends the processing.

  By the above processing, the user sets the plane coordinate system in the direction in which measurement is easy, and inputs the marker information by inputting the coordinates of the three points on the plane and the coordinates of the vertex of the marker in the plane coordinate system. Can do. For this reason, the user can easily input marker information.

  Note that the above method can be applied regardless of the regular polygon of the marker. That is, the rotation axis vector, the rotation angle, the barycentric coordinates, and the size can be obtained by the same processing as in steps S202, S203, S204, and S205.

[Other Embodiments]
As described above, the exemplary embodiments of the present invention have been described in detail. However, the present invention can take an embodiment as, for example, a system, an apparatus, a method, a program, or a storage medium. You may apply to the system comprised from an apparatus, and may apply to the apparatus which consists of one apparatus.

  The present invention can also be achieved by supplying a program that realizes the functions of the above-described embodiment directly or remotely to a system or apparatus, and the computer of the system or apparatus reads and executes the supplied program code. Including the case where it is achieved.

  Therefore, since the functions of the present invention are implemented by a computer, the program code installed in the computer is also included in the technical scope of the present invention. That is, the present invention includes a computer program itself for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, or the like.

  As a recording medium for supplying the program, for example, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, a client computer browser is used to connect to an Internet homepage, and the computer program of the present invention itself or a compressed file including an automatic installation function is downloaded from the homepage to a recording medium such as a hard disk. Can also be supplied. It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  In addition, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and key information for decryption is downloaded from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to execute the encrypted program by using the key information and install the program on a computer. In addition to the functions of the above-described embodiments being realized by the computer executing the read program, the OS running on the computer based on an instruction of the program is a part of the actual processing. Alternatively, the functions of the above-described embodiment can be realized by performing all of them and performing the processing.

  Furthermore, after the program read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion board or The CPU or the like provided in the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.

It is the figure which showed the marker which has an equilateral triangle shape exemplarily. It is the figure which showed the marker in a world coordinate system exemplarily. It is the figure which showed the marker hung on the diagonal plane exemplarily. It is the figure which showed the marker which has a shape of a regular tetragon. It is the figure which showed the square marker installed in the world coordinate system exemplarily. It is the figure which showed the marker file used in this embodiment exemplarily. It is the figure which showed the marker setting screen exemplarily. It is the figure which showed an example of the vertex designation | designated input screen. It is the figure which showed an example of the plane designation | designated input screen. It is a flowchart which shows the flow of the derivation process by vertex specification. P _i, V _i, the positional relationship of N _i is a diagram schematically showing. It is a flowchart which shows the flow of the derivation | leading-out process by plane designation | designated. It is the figure which showed typically a mode that the coordinate of vertex Q and _Mf was calculated _| required from the coordinate of vertex A and B. FIG. E _x, E _y, is a diagram schematically showing the positional relationship of the N _p. It is a block diagram which shows the apparatus structure of information processing apparatus. It is the flowchart which showed the whole flow of marker information derivation processing.

Claims (16)

A display step of displaying an interface for inputting the vertex coordinates of the index on the display device;
And a deriving step of deriving index information used for drawing a CG image based on the vertex coordinates input from the interface.   The information processing method according to claim 1, wherein the derivation step corrects a measurement error of the vertex coordinates by averaging a plurality of pieces of index information obtained based on the vertex coordinates. The display step displays a schematic diagram of the indicator on the interface,
The information according to claim 1, wherein the interface includes a display that allows the user to know which vertex of the schematic diagram corresponds to the vertex coordinates input by the user. Processing method. A display step for displaying on the display device an interface for inputting coordinates of three or more points on a plane including the index and two or more vertex coordinates of the index in a coordinate system set on the plane; ,
And a derivation step of deriving index information used for appropriate rendering of a CG image from the coordinates of the three or more points and the two or more vertex coordinates input from the interface. Method. The display step displays a schematic diagram of the three or more points and the two or more vertices on the interface,
5. The information processing method according to claim 4, wherein the interface includes a display that allows the user to know which point or vertex of the schematic diagram corresponds to coordinates input by the user. .   6. The information processing method according to claim 1, wherein the display step further causes the interface to display the index information derived by the derivation step.   The information processing method according to claim 1, wherein the index information is at least one of a barycentric coordinate, a rotation axis vector, a rotation angle, and a size of the index. An information processing method for setting index information having position information and posture information,
In response to a user instruction, position information regarding a plurality of feature points of the index is set,
From the position information regarding the set feature points, the position information and posture information of the index are obtained,
The information processing method characterized by registering the obtained position information and posture information as index information of the index. The shape of the indicator is a flat rectangle,
The information processing method according to claim 8, wherein the feature point is a vertex of the rectangle.   9. The information processing according to claim 8, wherein the index includes information indicating a reference point, and the plurality of feature points are identified on the basis of a feature point whose position is specified based on the reference point. Method.   9. The information processing method according to claim 8, wherein the shape of the index and the position of the feature point with respect to the shape of the index are visually presented to the user.   The information processing method according to claim 11, wherein information related to posture information of the index is visually presented to a user. An information processing method for setting index information having position information and posture information,
Set the plane information of the plane where the index is arranged according to the user's instruction,
According to the user's instruction, set the position information of the feature point of the index,
Based on the plane information and the position information of the feature points, obtain the position information and posture information of the index,
The information processing method characterized by registering the obtained position information and posture information as index information of the index.   A computer program for causing a computer to execute the information processing method according to claim 1.   A computer-readable storage medium storing the computer program according to claim 14. Input means as an interface for inputting the vertex coordinates of the marker;
An information processing apparatus comprising: derivation means for deriving marker information used for drawing a CG image based on the vertex coordinates input from the input means.

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