JP2014071619A - Subject detection device, subject detection method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly estimate the attitude of a specific subject with respect to an imaging part.SOLUTION: A portable terminal 100 includes a coordinate detection part 6c detecting the coordinates of a plurality of points constituting the image area of the specific subject in an acquired image, a first attitude candidate estimation part 6d estimating at least one of the attitude candidates of the specific subject with respect to an imaging part 3, based on the detected coordinates of the plurality of points, and an attitude specifying part 6f specifying one of the estimated attitude candidates as the optimal solution of the attitude of the specific subject with respect to the imaging part.

Description

  The present invention relates to a subject detection device, a subject detection method, and a program.

Conventionally, as an augmented reality (AR) technique, an image processing apparatus that displays a virtual object (for example, a three-dimensional model) in association with an image of a marker (real object) in a captured image is known. (For example, refer to Patent Document 1).
In this image processing apparatus, based on the result of image analysis of the captured frame image, the inclination of the image of the marker in the frame image (for example, the rotation angle from the normal viewing state in the display screen) is detected, and the marker Is recorded as an initial value. In addition, the image processing apparatus calculates a relative difference between the inclination of the marker in the sequentially captured frame image and the inclination recorded as the initial value, specifically, a difference in coordinate values. Then, the image processing apparatus performs a process of sequentially displaying the virtual object image tilted along a predetermined vector from the calculated coordinate value difference.

JP 2006-72667 A

  However, depending on the environment and various conditions at the time of imaging of the marker, detection errors of the four corner points of the marker in the three-dimensional space occur, and it is possible to appropriately estimate the posture of the marker with respect to the imaging unit. There is a possibility that it cannot be done.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a subject detection apparatus, a subject detection method, and a program capable of appropriately estimating the posture of a specific subject with respect to an imaging unit. Is to provide.

In order to solve the above problems, a subject detection apparatus according to the present invention provides:
Acquisition means for sequentially acquiring an image including a specific subject imaged by the imaging unit; and detection means for detecting coordinates of a plurality of points constituting the image area of the specific subject in the image acquired by the acquisition means; , Candidate estimation means for estimating at least one attitude candidate of the specific subject with respect to the imaging unit based on the coordinates of the plurality of points detected by the detection means; and the attitude estimated by the candidate estimation means And a specifying unit that specifies any one of the candidates as an optimal solution of the posture of the specific subject with respect to the imaging unit.

The subject detection method according to the present invention includes:
A method for detecting an object using an object detection device, comprising: sequentially acquiring an image including a specific object imaged by an imaging unit; and a plurality of points constituting an image area of the specific object in the acquired image A process of detecting the coordinates of the plurality of points, a process of estimating at least one attitude candidate of the specific subject with respect to the imaging unit based on the detected coordinates of the plurality of points, and among the estimated attitude candidates And a process of specifying any one as an optimal solution of the posture of the specific subject with respect to the imaging unit.

The program according to the present invention is
An acquisition unit that sequentially acquires an image including a specific subject imaged by the imaging unit, and coordinates of a plurality of points constituting an image area of the specific subject in the image acquired by the acquisition unit A detection means for detecting the position, a candidate estimation means for estimating at least one posture candidate of the specific subject relative to the imaging unit based on the coordinates of the plurality of points detected by the detection means, and the estimation by the candidate estimation means Any one of the posture candidates is made to function as a specifying unit that specifies an optimal solution of the posture of the specific subject with respect to the imaging unit.

  According to the present invention, it is possible to appropriately estimate the posture of a specific subject with respect to the imaging unit.

It is a block diagram which shows schematic structure of the portable terminal of Embodiment 1 to which this invention is applied. It is a flowchart which shows an example of the operation | movement which concerns on the marker detection process by the portable terminal of FIG. It is a figure which shows typically the positional relationship of the portable terminal of FIG. 1, and a marker. It is a figure for demonstrating the marker detection process of FIG. It is a block diagram which shows schematic structure of the portable terminal of Embodiment 2 to which this invention is applied. It is a flowchart which shows an example of the operation | movement which concerns on the marker detection process by the portable terminal of FIG.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

[Embodiment 1]
FIG. 1 is a block diagram showing a schematic configuration of a mobile terminal 100 according to the first embodiment to which the present invention is applied.
As shown in FIG. 1, the mobile terminal 100 of the present embodiment includes a central control unit 1, a memory 2, an imaging unit 3, an imaging control unit 4, an image data generation unit 5, and a marker detection processing unit 6. A display unit 7, a display control unit 8, a transmission / reception unit 9, a communication control unit 10, an operation input unit 11, and the like.
The mobile terminal 100 includes, for example, an imaging device having a communication function, a mobile station used in a mobile communication network such as a mobile phone or a PHS (Personal Handy-phone System), a PDA (Personal Data Assistants), and the like. Has been.

  The central control unit 1 controls each unit of the mobile terminal 100. Specifically, the central control unit 1 includes a CPU (not shown) that controls each part of the mobile terminal 100, and performs various control operations according to various processing programs (not shown).

  The memory 2 is composed of, for example, a DRAM (Dynamic Random Access Memory) or the like, and is a buffer memory that temporarily records image information, a working memory such as the central control unit 1, and various programs related to the functions of the mobile terminal 100 And a program memory (not shown) in which data is stored.

The imaging unit 3 captures a specific subject (for example, the marker M) and generates an image signal of the frame image F (see FIG. 3).
Here, the specific subject may be a two-dimensional image or a three-dimensional solid. For example, when a specific subject is a two-dimensional image, a substantially frame-shaped (frame-shaped) marker M having a square with a side of 12 mm can be used (see FIG. 3).
The shape and dimensions of the marker M described above are merely examples, and are not limited thereto, and can be arbitrarily changed as appropriate.

The imaging unit 3 includes a lens unit 3a and an electronic imaging unit 3b.
The lens unit 3a includes a plurality of lenses such as a zoom lens and a focus lens.
The electronic imaging unit 3b is composed of, for example, an image sensor such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS), and converts an optical image that has passed through various lenses of the lens unit 3a into a two-dimensional image signal. To do.
In addition, although illustration is abbreviate | omitted, the imaging part 3 may be provided with the aperture_diaphragm | restriction which adjusts the quantity of the light which passes the lens part 3a.

The imaging control unit 4 controls the imaging of the subject by the imaging unit 3. That is, the imaging control unit 4 includes a timing generator, a driver, and the like, although not illustrated. Then, the imaging control unit 4 scans and drives the electronic imaging unit 3b with a timing generator and a driver, converts the optical image into a two-dimensional image signal with the electronic imaging unit 3b at a predetermined period, and the electronic imaging unit 3b. The frame image F is read out from the imaging area for each screen and is output to the image data generation unit 5.
In addition, the imaging control unit 4 performs adjustment control of imaging conditions of the subject such as AF (automatic focusing process), AE (automatic exposure process), AWB (automatic white balance), and the like.

The image data generation unit 5 appropriately adjusts the gain for each RGB color component with respect to the analog value signal of the frame image F transferred from the electronic image pickup unit 3b, and then samples and holds it by a sample hold circuit (not shown). The digital data is converted into digital data by an A / D converter (not shown), color processing including pixel interpolation processing and γ correction processing is performed by a color process circuit (not shown), and then a digital luminance signal Y and color difference signal Cb, Cr (YUV data) is generated.
Further, the image data generation unit 5 reduces the YUV data of the generated frame image F at a predetermined magnification in both horizontal and vertical directions, and generates low-resolution (for example, VGA, QVGA size, etc.) image data for live view display. Is generated. Specifically, the image data generation unit 5 has low resolution image data for live view display from YUV data of the frame image F at a predetermined timing according to a predetermined display frame rate of the live view image by the display unit 7. Is generated.

  Then, the image data generation unit 5 sequentially outputs the generated YUV data of each frame image F to the memory 2 and stores it in the memory 2.

The marker detection processing unit 6 includes a temporary posture designation unit 6a, an image acquisition unit 6b, a coordinate detection unit 6c, a first posture candidate estimation unit 6d, a determination unit 6e, a first posture specification unit 6f, and an image generation 6g.
In addition, although each part of the marker detection process part 6 is comprised from the predetermined | prescribed logic circuit, for example, the said structure is an example and is not restricted to this.

The temporary posture designation unit 6a designates the temporary posture of the marker M with respect to the terminal body in advance.
That is, the provisional posture designation unit (designation unit) 6a designates the provisional posture of the marker (specific subject) M with respect to the terminal body including the imaging unit 3 in advance. Specifically, for example, based on a predetermined operation of the operation input unit 11 by the user, the normal direction of the marker M, which is a two-dimensional image, with respect to the two-dimensional plane (that is, the Z axis in the marker coordinate system in FIG. 3). Direction) (for example, any one of up, down, left, and right directions) is input, the temporary posture designating unit 6a determines the normal direction of the input marker M with respect to the two-dimensional plane with respect to the terminal body. The temporary posture of the marker M is designated.
Note that the provisional posture designation method is an example, and is not limited thereto, and can be arbitrarily changed as appropriate. For example, the temporary posture may be configured so that a preset default posture is automatically specified.

The image acquisition unit 6b sequentially acquires a plurality of frame images F,.
That is, the image acquisition unit (acquisition unit) 6b sequentially acquires a plurality of images in which the marker (specific subject) M is continuously captured. Specifically, the image acquisition unit 6b has a predetermined resolution image data (for example, a plurality of frame images F, which are sequentially generated by the image data generation unit 5 after the marker M is continuously captured by the imaging unit 3). , Luminance data) from the memory 2 sequentially.

The coordinate detection unit 6c detects the coordinates of a plurality of points constituting the marker image region S (see FIG. 3).
That is, the coordinate detection unit (detection unit) 6c detects the coordinates of a plurality of points (for example, four corner points) constituting the marker image region S included in the frame image F acquired by the image acquisition unit 6b. . Specifically, the coordinate detection unit 6c applies to the image data of the binarized image generated by performing a predetermined binarization process on the frame image F acquired by the image acquisition unit 6b. A predetermined feature extraction process is performed to extract a substantially frame-shaped marker image region S. Then, the coordinate detection unit 6c detects the position coordinates of the four corners constituting the marker image region S.
Note that the feature extraction process is a known technique, and thus detailed description thereof is omitted here.

  The first posture candidate estimation unit 6d estimates at least one posture candidate of the marker M with respect to the terminal body. Specifically, the first posture candidate estimation unit 6d includes a first estimation unit d1 and a second estimation unit d2.

The first estimation unit (first estimation unit) d1 estimates the first posture candidate of the marker M with respect to the terminal body based on the coordinates of the plurality of points detected by the coordinate detection unit 6c. Specifically, the first estimation unit d1 refers to a database (not shown) recorded in a predetermined recording unit and the geometric positional relationship from the position coordinates of the four corner points of the marker image region S. A coordinate conversion formula (for example, see formula (1); described later) that defines the correspondence between the coordinates of each point of the marker M in the three-dimensional space and the two-dimensional plane coordinates in the frame image F is used. A first initial value is calculated.
Here, for coordinate conversion of a plurality of points in the marker image region S, for example, a center projection model with relatively high accuracy may be used, or a pseudo center projection model (FIG. 4) with lower accuracy than the center projection model. (Refer to (a)). For example, in the pseudo-central projection model, when a predetermined distance or more away from the mobile terminal 100, it is regarded as parallel projection in a narrow range in the front-rear direction (depth direction) with respect to the terminal body, and the point 1 in FIG. 2 is projected onto the point a of the image.

なお、式（１）の座標変換式は、同次座標変換行列である。また、当該式（１）中、「Ｘ_ｗ」、「Ｙ_ｗ」及び「Ｚ_ｗ」は、互いに直交するＸ軸、Ｙ軸及びＺ軸により規定される三次元空間でのマーカーＭを構成する各点の座標位置を表し、「ｘ_ｉ」及び「ｙ_ｉ」は、Ｘ軸及びＹ軸により規定される二次元平面であるフレーム画像Ｆ内でマーカーＭの各点の対応する座標位置を表している。
また、端末本体に対するマーカーＭの姿勢を表す行列Ｒは、具体的には、ｎ行ｍ列の行列（ｎ、ｍは、それぞれ自然数）で表され、例えば、３×３の回転行列等が挙げられる。また、端末本体に対するマーカーＭの位置関係を表す行列Ｔは、具体的には、ｎ行ｍ列の行列（ｎ、ｍは、それぞれ自然数）で表され、例えば、１×３の並進ベクトル等が挙げられる。
また、式（１）中の「Ｃ」は、撮像部３の焦点距離等の内部パラメータを表し、「ｈ」は、フレーム画像Ｆのスケールを表している。 In addition, the first estimation unit d1 uses the calculated first initial value as an initial value of the matrix R representing the attitude of the marker M with respect to the terminal body, and solves the coordinate transformation expression of the following formula (1), thereby making the marker for the terminal body Matrixes R and T representing the posture and positional relationship of M are estimated by bundle adjustment. And the 1st estimation part d1 specifies the estimated matrix R as a 1st attitude | position candidate of the marker M with respect to a terminal main body.
Here, bundle adjustment is a method for estimating geometric model parameters from an image in order to achieve high estimation accuracy, for example, a method for minimizing the total reprojection error of unknown parameters. Etc. are used.

In addition, the coordinate conversion formula of Formula (1) is a homogeneous coordinate conversion matrix. Moreover, in the said Formula (1), " _Xw ", " _Yw ", and " _Zw " comprise the marker M in the three-dimensional space prescribed | regulated by the mutually orthogonal X-axis, Y-axis, and Z-axis. The coordinate position of each point is represented, and “x _i ” and “y _i ” represent the corresponding coordinate position of each point of the marker M in the frame image F which is a two-dimensional plane defined by the X axis and the Y axis. ing.
Further, the matrix R representing the attitude of the marker M with respect to the terminal body is specifically represented by a matrix of n rows and m columns (n and m are natural numbers, respectively), for example, a 3 × 3 rotation matrix or the like. It is done. Further, the matrix T representing the positional relationship of the marker M with respect to the terminal body is specifically represented by a matrix of n rows and m columns (n and m are natural numbers, respectively), for example, a 1 × 3 translation vector or the like. Can be mentioned.
Further, “C” in Expression (1) represents an internal parameter such as a focal length of the imaging unit 3, and “h” represents a scale of the frame image F.

The second estimation unit (second estimation unit) d2 estimates a second posture candidate different from the first posture candidate of the marker M with respect to the terminal body based on the estimation result by the first estimation unit d1.
Specifically, the second estimation unit d2 estimates the second posture candidate of the marker M with respect to the terminal body when the determination unit 6e determines that the first posture candidate is incorrect (described later in detail). That is, when the determination unit 6e determines that the first posture candidate is not correct, the first posture candidate is considered to be a local solution estimated by bundle adjustment, so the first posture candidate estimation unit 6d The posture estimation candidate (second posture candidate) of the marker M with respect to the terminal body is estimated again by the second estimation unit d2.
For example, the second estimation unit d2 calculates the outer product of a predetermined position of the terminal body (for example, the center of the terminal body through which the optical axis passes), the axis passing through the center of the marker M (center axis), and the normal vector of the marker M on the two-dimensional plane Is calculated. Then, the second estimation unit d2 is opposite to the provisional posture of the marker M (for example, downward; the direction of the marker M represented by the broken line L2 in FIG. 4B) designated by the provisional posture designation unit 6a (for example, The second initial value is calculated by rotating the matrix R, which is the first posture candidate, about the calculated outer product as an axis so as to be upward (the direction of the marker M represented by the solid line L1 in FIG. 4B). . Thereafter, the second estimation unit d2 uses the calculated second initial value as an initial value of a matrix R representing the attitude of the marker M with respect to the terminal body, and thereby solves the coordinate conversion equation of Expression (1), whereby the marker M with respect to the terminal body. Matrixes R and T representing the posture and positional relationship are estimated, and the estimated matrix R is specified as a second posture candidate of the marker M with respect to the terminal body.
Note that the second posture candidate estimation method is an example and is not limited to this, and can be arbitrarily changed as appropriate. For example, the second estimation unit d2 uses the pseudo-center projection model from the coordinates of the four corner points of the marker image region S, similarly to the first estimation unit d1, thereby converting the coordinate conversion formula (for example, formula (1 ))), A second initial value different from the first initial value is calculated, and a matrix R (second attitude candidate) representing the attitude of the marker M with respect to the terminal body is calculated by bundle adjustment using the second initial value. It may be estimated.

  Thus, since the second estimation unit d2 estimates the second posture candidate only when the determination unit 6e determines that the first posture candidate is not correct, the first posture candidate estimation unit 6d (candidate estimation means) Estimates at least one posture candidate of the marker M with respect to the terminal body including the imaging unit 3.

The determination unit 6e determines whether or not the first posture candidate is correct.
That is, the determination unit (determination unit) 6e determines whether the first posture candidate estimated by the first estimation unit d1 is correct according to a predetermined determination criterion. Specifically, the determination unit 6e determines whether or not the first posture candidate of the marker M with respect to the terminal body is correct based on the temporary posture of the marker M designated by the temporary posture designation unit 6a.
For example, when the matrix R representing the first posture candidate of the marker M with respect to the terminal body is represented by a 3 × 3 rotation matrix, each element r ₁₁ , r ₂₁ , r ₃₁ in the first column is the coordinates of the terminal body. Represents the direction of the X axis of the marker coordinate system in the system, and each element r ₁₂ , r ₂₂ , r ₃₂ in the second column represents the direction of the Y axis of the marker coordinate system in the coordinate system of the terminal body. each element r _13, r _23, r ₃₃ represents the direction of Z-axis of the marker coordinate system in the coordinate system of the terminal body. Here, for example, when the orientation of the normal direction with respect to the two-dimensional plane of the marker M is designated in advance by the temporary posture designation unit 6a, the determination unit 6e represents the first posture candidate of the marker M with respect to the terminal body. By confirming the sign of a predetermined element of the matrix R (for example, element r _{23 in the} second row and third column), it is determined whether or not the first posture candidate matches the temporary posture. That is, since the normal direction of the marker M coincides with the Z-axis direction of the marker coordinate system, the determination unit 6e displays the third column indicating the Z-axis direction of the marker coordinate system of the 3 × 3 rotation matrix. By confirming the sign of the element r ₂₃ corresponding to the Y axis of the coordinate system of the terminal body, the normal direction of the marker M faces the positive direction of the Y axis of the coordinate system of the terminal body. It can be determined whether or not.

Note that the determination method of the first posture candidate is an example, and is not limited to this, and can be arbitrarily changed as appropriate.
Specifically, for example, the determination unit 6e determines that the first posture candidate is correct based on the change in posture of the marker M with respect to the terminal body that is sequentially identified as the optimal solution by the first posture identification unit 6f (described later). It may be determined whether or not. For example, when the frame image F is captured and acquired at a predetermined imaging frame rate (for example, 60 fps), predetermined first posture candidates corresponding to a plurality of frame images F,. The ratio of the posture of the marker M in a predetermined direction (for example, upward) is calculated based on the above elements, and when the ratio becomes a predetermined value or more, it is determined that the first posture candidate is correct. good. Further, for example, the determination unit 6e compares the predetermined element of the first posture candidate specified last time with the first posture according to whether or not the predetermined element of the first posture candidate specified this time matches. You may make it determine whether a candidate is correct.
In this case, the mobile terminal 100 does not necessarily need to include the temporary posture specifying unit 6a.

The first posture specifying unit 6f specifies an optimal solution for the posture of the marker M with respect to the terminal body.
That is, the first posture specifying unit (specifying unit) 6f specifies any one of at least one posture candidate estimated by the first posture candidate estimating unit 6d as the optimum solution of the posture of the marker M with respect to the terminal body. . Specifically, the first posture specifying unit 6f specifies one of the first posture candidate and the second posture candidate as the optimal solution.
For example, when the determination unit 6e determines that the first posture candidate is correct, the first posture specifying unit 6f specifies the first posture candidate as the optimal solution, and determines that the first posture candidate is not correct. In such a case, the second posture candidate estimated by the second estimation unit d2 is specified as the optimal solution.
That is, when the determination unit 6e determines that the first posture candidate is correct, only the first posture candidate (first posture candidate) is estimated by the first posture candidate estimation unit 6d. The specifying unit 6f specifies the first posture candidate as a matrix R representing the posture of the marker M with respect to the terminal body. On the other hand, when the determination unit 6e determines that the first posture candidate is not correct, the second estimation unit d2 of the first posture candidate estimation unit 6d re-estimates the second posture candidate, and the first posture The specifying unit 6f specifies the second posture candidate as a matrix R representing the posture of the marker M with respect to the terminal body.

The image generation unit 6g superimposes a virtual object (for example, a three-dimensional model; not shown) corresponding to the marker M on the marker image region S of the frame image F sequentially acquired by the image acquisition unit 6b. (Not shown).
Specifically, for example, every time the frame image F is sequentially acquired, the image generation unit 6g is based on the posture and positional relationship of the marker M with respect to the terminal body identified as the optimal solution by the first posture identification unit 6f. Then, the posture (orientation) and position of the marker image in the frame image F are adjusted, a virtual object corresponding to the marker image is acquired from a predetermined recording means, and image data of the virtual image is generated. Then, the image generation unit 6 g sequentially outputs the generated image data of each virtual image to the memory 2 and stores it in the memory 2.
The image data of the virtual image generated by the image generation unit 6g is encoded in a predetermined compression format (for example, JPEG format, for example), and is a recording medium (not shown) such as a nonvolatile memory (flash memory). May be recorded.

  The display unit 7 is configured by, for example, a liquid crystal display panel, and displays an image (for example, a live view image) captured by the imaging unit 3 based on a video signal from the display control unit 8 on a display screen.

The display control unit 8 performs control to read display image data temporarily stored in the memory 2 and display it on the display unit 7.
Specifically, the display control unit 8 includes a VRAM (Video Random Access Memory), a VRAM controller, a digital video encoder, and the like. The digital video encoder reads the luminance signal Y and the color difference signals Cb and Cr read from the memory 2 and stored in the VRAM (not shown) under the control of the central control unit 1 through the VRAM controller. Are read out at a predetermined playback frame rate (for example, 30 fps), and a video signal is generated based on these data and output to the display unit 7.
For example, the display control unit 8 updates the plurality of frame images F captured by the imaging unit 3 and the imaging control unit 4 and generated by the image data generation unit 5 to the display unit 7 while sequentially updating at a predetermined display frame rate. Display live view. For example, the display control unit 8 sequentially acquires image data of virtual images from the memory 2 and sequentially displays the virtual images on the display unit 7 in live view.

The transmitter / receiver unit 9 performs a call with an external user of an external device connected via the communication network N.
Specifically, the transmission / reception unit 9 includes a microphone 9a, a speaker 9b, a data conversion unit 9c, and the like. The transmission / reception unit 9 performs A / D conversion processing on the user's transmission voice input from the microphone 9a by the data conversion unit 9c and outputs the transmission voice data to the central control unit 1. Under the control, voice data such as received voice data outputted and inputted from the communication control unit 10 is D / A converted by the data conversion unit 9c and outputted from the speaker 9b.

The communication control unit 10 transmits and receives data via the communication network N and the communication antenna 10a.
That is, the communication antenna 10a is connected to a predetermined communication method (for example, W-CDMA (Wideband Code Division Multiple Access) method, GSM (Global System)) used by the mobile terminal 100 for communication with a radio base station (not shown). for Mobile Communications (registered trademark) system, etc.). The communication control unit 10 transmits / receives data to / from the radio base station via the communication antenna 10a using a communication channel set in the communication method according to a communication protocol corresponding to a predetermined communication method.
That is, the communication control unit 10 transmits and receives voice during a call with an external user of the external device to the external device of the communication partner based on the instruction signal output from the central control unit 1 and input, Send and receive e-mail data.
Note that the configuration of the communication control unit 10 is an example and is not limited to this, and can be arbitrarily changed as appropriate. For example, although not illustrated, a wireless LAN module is mounted and an access point (Access Point) is provided. It is good also as a structure which can access the communication network N via this.

  The communication network N is a communication network that connects the mobile terminal 100 via a wireless base station, a gateway server (not shown), or the like. The communication network N is a communication network constructed by using a dedicated line or an existing general public line, and applies various line forms such as a LAN (Local Area Network) and a WAN (Wide Area Network). Is possible. The communication network N includes, for example, various communication network networks such as a telephone line network, ISDN line network, dedicated line, mobile communication network, communication satellite line, CATV line network, IP network, VoIP (Voice over Internet Protocol). ) Gateways, Internet service providers, etc. are included.

The operation input unit 11 is for inputting various instructions to the terminal body.
Specifically, the operation input unit 11 executes a shutter button according to an instruction to shoot a subject, up / down / left / right cursor buttons and a determination button according to a selection instruction of a mode, a function, etc. Various buttons (not shown) such as communication-related buttons related to instructions and numeric buttons and symbol buttons related to text input instructions are provided.
When various buttons are operated by the user, the operation input unit 11 outputs an operation instruction corresponding to the operated button to the central control unit 1. The central control unit 1 causes each unit to execute a predetermined operation (for example, imaging of a subject, incoming / outgoing calls, transmission / reception of an e-mail, etc.) according to an operation instruction output from the operation input unit 11 and input.

  The operation input unit 11 may include a touch panel provided integrally with the display unit 7, and an operation instruction corresponding to the predetermined operation is given to the central control unit based on a predetermined operation of the touch panel by the user. 1 may be output.

Next, marker detection processing by the mobile terminal 100 will be described with reference to FIG.
FIG. 2 is a flowchart illustrating an example of an operation related to the marker detection process.
In addition, the marker M detected by the following marker detection process shall be arrange | positioned in the predetermined position in the pot of the potted houseplant, for example.

As shown in FIG. 2, first, the temporary posture designating unit 6 a sets the normal direction (for example, downward) of the marker M input based on a predetermined operation of the operation input unit 11 by the user with respect to the two-dimensional plane. The temporary posture of the marker M with respect to the terminal body is designated (step S1).
Thereafter, the imaging control unit 4 causes the imaging unit 3 to image the marker M, and the image data generation unit 5 generates image data of a plurality of frame images F,... Transferred from the electronic imaging unit 3b (step S2). . Here, for example, when the focal length of the lens unit is 40 mm (35 mm size conversion) and a substantially frame-shaped marker M having a square with a side of 12 mm is imaged from a location about 40 cm away, the marker image is a frame image F of VGA size. One side of the region S is about 50 pixels. In such a situation, detection errors of the coordinates of the four corner points of the marker image region S described later are likely to occur.
Then, the image data generation unit 5 sequentially outputs the generated YUV data of each frame image F to the memory 2 and stores it in the memory 2.

  Next, the image acquisition unit 6b of the marker detection processing unit 6 acquires image data of any one of the frame images F sequentially generated by the image data generation unit 5 from the memory 2 (step S3). Subsequently, the coordinate detection unit 6c performs a predetermined feature extraction process on the image data of the binarized image of the frame image F acquired by the image acquisition unit 6b to extract a substantially frame-shaped marker image region S. Then, the position coordinates of the four corner points constituting the extracted marker image region S are detected (step S4).

Next, the first estimation unit d1 uses the geometrical positional relationship from the coordinates of the four corner points of the marker image region S to determine the coordinates of each point of the marker M in the three-dimensional space and the frame image F. A first initial value of a coordinate conversion formula (for example, formula (1)) that defines the correspondence relationship with the two-dimensional plane coordinates is calculated (step S5). Subsequently, the first estimation unit d1 uses the calculated first initial value to solve the coordinate transformation formula of the following formula (1), thereby matrixes R and T representing the posture and positional relationship of the marker M with respect to the terminal body. Is estimated by bundle adjustment, and the estimated matrix R is specified as the first posture candidate of the marker M with respect to the terminal body (step S6).

Next, the determination unit 6e determines whether or not the first posture candidate of the marker M with respect to the terminal body is correct based on the temporary posture of the marker M designated by the temporary posture designation unit 6a (step S7). Specifically, the determination unit 6e confirms the sign of a predetermined element (for example, element r _{23 in the} second row and third column) of the matrix R representing the first posture candidate of the marker M with respect to the terminal body. It is determined whether or not the first posture candidate matches the provisional posture, and it is determined whether or not the first posture candidate is correct according to the determination result.

When it is determined in step S7 that the first posture candidate is correct (step S7; YES), the first posture specifying unit 6f uses the first posture candidate as the optimal matrix R that represents the posture of the marker M with respect to the terminal body. It is specified as a solution (step S8).
Then, the image generation unit 6g adjusts the posture and position of the marker image in the frame image F based on the posture (first posture candidate) and the positional relationship of the marker M with respect to the terminal body identified as the optimal solution, and Image data of a virtual image in which a virtual object corresponding to the marker image is superimposed in the frame image F is generated. Then, the display control unit 8 displays the virtual image on the display unit 7 in live view (step S9).
Thereafter, the CPU of the central control unit 1 returns the process to step S3.

On the other hand, when it is determined in step S7 that the first posture candidate is not correct (step S7; NO), the second estimation unit d2 calculates the second initial value of the coordinate transformation equation using the first posture candidate. (Step S10). Specifically, the second estimating unit d2 calculates the outer product of the normal vector of the two-dimensional plane of the marker M and the axis (center axis) passing through the center of the terminal body through which the optical axis passes and the center of the marker M. Then, the second estimation unit d2 uses the calculated outer product as an axis so as to be opposite to the provisional posture (for example, downward) of the designated marker M (for example, upward), as a matrix R that is a first posture candidate. Is rotated to calculate the second initial value.
Subsequently, the second estimation unit d2 uses the calculated second initial value to solve the coordinate conversion equation of Equation (1), thereby obtaining matrices R and T representing the posture and positional relationship of the marker M with respect to the terminal body. The estimation is performed by bundle adjustment, and the estimated matrix R is specified as the second posture candidate of the marker M with respect to the terminal body (step S11).

Thereafter, the first attitude specifying unit 6f specifies the second attitude candidate as an optimal solution of the matrix R representing the attitude of the marker M with respect to the terminal body (step S12). Then, the CPU of the central control unit 1 shifts the process to step S9 and controls the execution of each process thereafter.
That is, in step S9, the image generation unit 6g determines the posture or position of the marker image in the frame image F based on the posture (second posture candidate) and the positional relationship of the marker M with respect to the terminal body identified as the optimal solution. And image data of a virtual image in which a virtual object corresponding to the marker image is superimposed in the frame image F is generated. Then, the display control unit 8 displays the virtual image on the display unit 7 in live view.

  Each of the above processes is repeatedly executed every time the frame image F is acquired in step S3.

As described above, according to the mobile terminal 100 of the first embodiment, the marker for the imaging unit 3 (terminal body) is based on the coordinates of the coordinates of a plurality of points that form the image area S of the marker (specific subject) M. Since at least one of the M posture candidates is estimated, and any one of the estimated posture candidates is specified as the optimum solution of the posture of the marker M with respect to the imaging unit 3, the environment at the time of imaging the marker M and various types Even in an environment where a detection error of a plurality of points constituting the marker image region S occurs depending on conditions or the like and the local solution is easily calculated, the optimal solution can be appropriately specified without falling into the local solution, The posture of the marker M with respect to the imaging unit 3 can be estimated appropriately.
That is, for example, when the distance from the imaging unit 3 of the mobile terminal 100 to the marker M is relatively long, it is regarded as parallel projection, and detection errors of a plurality of points constituting the marker image region S are likely to occur. In addition, the marker image region S cannot be properly specified in an environment with strong sunlight or darkness, and as a result, detection errors of a plurality of points constituting the marker image region S are likely to occur. In addition, the reliability of the detection results of a plurality of points constituting the marker image region S also decreases when the imaging frame rate is relatively high. In such an environment, even if the posture of the marker M with respect to the imaging unit 3 is estimated from the coordinates of a plurality of points in the marker image region S using the central projection model, a local solution is likely to be calculated.
Therefore, in this embodiment, instead of directly estimating one optimal solution of the posture of the marker M with respect to the imaging unit 3, although there may be a local solution, the posture candidate of the marker M with respect to the imaging unit 3 is estimated in advance. In addition, by specifying the optimal solution for the posture of the marker M with respect to the imaging unit 3 from the posture candidates, the local solution for the posture of the marker M with respect to the imaging unit 3 is finally specified. Can be suppressed.
As a result, the posture of the marker M with respect to the imaging unit 3 can be appropriately estimated, and as a result, the virtual object corresponding to the marker M can be properly displayed.

Further, when the first posture candidate of the marker (specific subject) M with respect to the imaging unit 3 is estimated based on the coordinates of a plurality of points in the marker image region S, and the first posture candidate is determined to be incorrect. Since the second posture candidate of the marker M with respect to the imaging unit 3 is estimated based on the estimation result of the first posture candidate, one of the first posture candidate and the second posture candidate can be specified as the optimum solution. . That is, when the first posture candidate is determined to be correct, the first posture candidate can be specified as the optimal solution, while when the first posture candidate is determined to be incorrect, the second posture candidate Can be specified as the optimal solution.
Specifically, for example, when the posture of the marker M with respect to the imaging unit 3 is estimated from the coordinates of a plurality of points in the marker image region S using the pseudo center projection model, the direction of the normal direction of the marker M with respect to the two-dimensional plane Can be estimated. At this time, when it is determined that the first posture candidate is correct, the first posture candidate can be specified as the optimal solution, and when it is determined that the first posture candidate is not correct, the first posture is determined. A second posture candidate different from the first posture candidate can be estimated in consideration of the candidate estimation result, and the second posture candidate can be specified as an optimal solution.

  Further, the first posture candidate is based on the provisional posture of the marker (specific subject) M with respect to the imaging unit 3 designated in advance or the manner of change in the posture of the marker M with respect to the imaging unit 3 that is sequentially identified as the optimal solution. It is possible to appropriately determine whether or not is correct, and it is possible to appropriately identify the optimal solution for the posture of the marker M with respect to the imaging unit 3.

  In the marker detection process of the above-described embodiment, a terminal that is determined by solving a coordinate conversion equation using the first initial value is determined as a determination target of whether or not the provisional posture in step S7 matches. Although the matrix R representing the posture of the marker M with respect to the main body is an example, the present invention is not limited to this. For example, the geometric positional relationship from the coordinates of the four corner points of the marker image region S in step S5. It is also possible to use a matrix R that represents the first initial value calculated using.

[Embodiment 2]
Below, the portable terminal 200 of Embodiment 2 is demonstrated.
The portable terminal 200 according to the second embodiment has substantially the same configuration as the portable terminal 100 according to the first embodiment except for the details described below, and detailed description thereof is omitted.

FIG. 5 is a block diagram illustrating a schematic configuration of the mobile terminal 200 according to the second embodiment to which the present invention is applied.
As illustrated in FIG. 5, the marker detection processing unit 206 of the mobile terminal 200 according to the second embodiment includes a temporary posture designation unit 6a, an image acquisition unit 6b, a coordinate detection unit 6c, a second posture candidate estimation unit 206d, A second posture specifying unit 206f and an image generating unit 6g are provided.
The temporary posture designation unit 6a, the image acquisition unit 6b, the coordinate detection unit 6c, and the image generation unit 6g have substantially the same configuration and processing as those provided in the mobile terminal 100 of the first embodiment, and detailed description thereof will be given here. Omitted.

The second posture candidate estimation unit 206d estimates a plurality of posture candidates for the marker M with respect to the terminal body including the imaging unit 3.
That is, the second posture candidate estimation unit 206d estimates a plurality of posture candidates for the marker M with respect to the terminal body based on the coordinates of the plurality of points detected by the coordinate detection unit 6c. Specifically, the second posture candidate estimation unit 206d refers to a database (not shown) or the like recorded in a predetermined recording unit, and determines the pseudo center projection model from the position coordinates of the four corner points of the marker image region S. Is used to determine the initial value of a coordinate transformation formula (for example, formula (1)) that defines the correspondence between the coordinates of each point of the marker M in the three-dimensional space and the two-dimensional plane coordinates in the frame image F. Calculate multiple. That is, the second posture candidate estimation unit 206d estimates a plurality of initial values of the matrix R representing the posture of the marker M with respect to the terminal body as posture candidates.

The 2nd attitude | position specific | specification part 206f specifies the optimal solution of the attitude | position of the marker M with respect to a terminal main body.
Specifically, the second posture specifying unit 206f optimally selects a plurality of posture candidates estimated by the second posture candidate estimating unit 206d that substantially matches the temporary posture specified by the temporary posture specifying unit 6a. Specify as a solution. For example, in the case where the normal orientation of the marker M with respect to the two-dimensional plane is designated in advance by the temporary orientation specifying unit 6a, the second orientation specifying unit 206f selects each orientation candidate (initial value) of the marker M relative to the terminal body. ) Indicating a predetermined posture (for example, the element r _{23 in the} second row and the third column) of the matrix R is determined to determine whether or not it matches the temporary posture. Then, the second posture specifying unit 206f specifies a posture candidate that substantially matches the temporary posture, and sets it as the final initial value of the coordinate conversion formula (for example, formula (1)).
Thereafter, the second posture identifying unit 206f uses the identified final initial values to solve the coordinate transformation equation of Equation (1), thereby matrixes R and T representing the posture and positional relationship of the marker M with respect to the terminal body. Is estimated by bundle adjustment, and the estimated matrix R is specified as the optimum solution of the posture of the marker M with respect to the terminal body.

The method for specifying the optimal solution is an example and is not limited to this, and can be arbitrarily changed as appropriate.
Specifically, for example, the second posture specifying unit 206f sequentially specifies the posture of the marker M with respect to the terminal body as the optimum solution, and optimizes the posture of the marker M with respect to the terminal body based on the change of the posture. You may make it specify a solution again. For example, when the frame image F is captured and acquired at a predetermined imaging frame rate (for example, 60 fps), a predetermined element having a posture corresponding to the plurality of frame images F,. Based on this, a ratio in which the attitude of the marker M is in a predetermined direction (for example, upward) is calculated, and when the ratio is equal to or greater than a predetermined value, the attitude of the marker M with respect to the terminal body is correct (is an optimal solution). It may be determined. In addition, for example, the second posture specifying unit 206f compares the predetermined element of the posture of the marker M with respect to the terminal body specified this time as compared with the predetermined element of the posture of the marker M with respect to the terminal main body specified as the optimal solution last time. Whether or not the posture of the marker M with respect to the terminal body is correct may be determined according to whether or not the two match.
In this case, the mobile terminal 200 does not necessarily have to include the temporary posture specifying unit 6a.

Next, marker detection processing by the mobile terminal 200 will be described with reference to FIG.
FIG. 6 is a flowchart illustrating an example of an operation related to the marker detection process.
In addition, the marker detection process by the portable terminal 200 is substantially the same as the marker detection process by the portable terminal 100 of the said Embodiment 1 except the point demonstrated in detail below, and detailed description is abbreviate | omitted.

As illustrated in FIG. 6, the mobile terminal 200 according to the second embodiment performs the processes of steps S <b> 1 to S <b> 4 in the same manner as the marker detection process according to the first embodiment.
That is, in step S1, the provisional posture designation unit 6a designates the provisional posture of the marker M with respect to the terminal body, and in step S2, the image data generation unit 5 transmits a plurality of frames transferred from the electronic imaging unit 3b. Image data of images F,... Is generated. In step S3, the image acquisition unit 6b acquires image data of any one of the frame images F sequentially generated by the image data generation unit 5. In step S4, the coordinate detection unit 6c The marker image area S is extracted from F, and the position coordinates of the four corner points constituting the marker image area S are detected.

  Thereafter, the second posture candidate estimation unit 206d estimates a plurality of initial values of the matrix R representing the posture of the marker M with respect to the terminal body as posture candidates (step S25). Specifically, the second posture candidate estimation unit 206d uses the pseudo-center projection model from the position coordinates of the four corner points of the marker image region S, and coordinates and frames of each point of the marker M in the three-dimensional space. A plurality of initial values of a coordinate transformation formula (for example, formula (1)) that defines the correspondence with the two-dimensional plane coordinates in the image F are calculated.

Next, the second posture specifying unit 206f specifies a plurality of posture candidates estimated by the second posture candidate estimating unit 206d that substantially matches the temporary posture specified by the temporary posture specifying unit 6a ( Step S26). Specifically, the second posture identifying unit 206f confirms the sign of a predetermined element (for example, the element r _{23 in the} second row and the third column) of the matrix R representing each posture candidate of the marker M with respect to the terminal body. Thus, it is determined whether or not it matches the temporary posture, and a posture candidate that substantially matches the temporary posture is set as the final initial value of the coordinate conversion equation (for example, equation (1)).
Subsequently, the second posture identifying unit 206f uses the identified final initial value to solve the coordinate transformation formula of the following formula (1), thereby expressing the matrix R representing the posture and positional relationship of the marker M with respect to the terminal body. , T are estimated by bundle adjustment. Then, the second posture specifying unit 206f specifies the estimated matrix R as the optimal solution for the posture of the marker M with respect to the terminal body.

Then, similarly to the marker detection process in the first embodiment, in step S9, the image generation unit 6g generates image data of a virtual image in which a virtual object corresponding to the marker image is superimposed in the frame image F, The display control unit 8 displays the virtual image on the display unit 7 in live view.
Thereafter, the CPU of the central control unit 1 returns the process to step S3.

As described above, according to the mobile terminal 200 of the second embodiment, similar to the mobile terminal 100 of the first embodiment, a plurality of marker image areas S are configured by the environment and various conditions when the marker M is imaged. Even in an environment where a point detection error occurs and the local solution is easily calculated, the optimal solution can be appropriately specified without falling into the local solution, and the posture of the marker M with respect to the imaging unit 3 can be estimated. It can be done properly.
In particular, by estimating a plurality of posture candidates in advance, it is possible to specify an optimum solution from among the plurality of posture candidates by selection, and it is easy to specify the optimum solution of the posture of the marker M with respect to the imaging unit 3. It can be carried out.

  In addition, among the estimated plurality of posture candidates, the one that substantially matches the provisional posture of the marker (specific subject) M with respect to the imaging unit 3 designated in advance is identified as the optimal solution, or the imaging unit 3 is selected as the optimal solution. Since the optimal solution of the marker M with respect to the image pickup unit 3 is sequentially specified and the optimal solution is specified again based on the change of the posture, the optimal solution of the posture of the marker M with respect to the imaging unit 3 can be appropriately specified.

The present invention is not limited to the above-described embodiment, and various improvements and design changes may be made without departing from the spirit of the present invention.
For example, the matrix R representing the posture of the marker M with respect to the terminal body (imaging unit 3) is specified by solving a predetermined coordinate conversion formula, but this is an example of the posture of the marker M with respect to the terminal body. However, the present invention is not limited to this, and can be arbitrarily changed as appropriate.
Further, the matrix T representing the positional relationship of the marker M with respect to the terminal body is specified by solving the coordinate conversion formula, but the positional relationship of the marker M with respect to the terminal body is not necessarily specified.

  Furthermore, the configuration of the mobile terminal 100 (200) is merely an example illustrated in the above embodiment, and is not limited thereto, and may include at least an acquisition unit, a detection unit, a candidate estimation unit, and a specification unit. If necessary, it can be arbitrarily changed. That is, the mobile terminal 100 (200) does not necessarily have to include the imaging unit 3, and performs processing for acquiring an image captured by an external imaging device and detecting a specific subject (marker M). May be.

In addition, in the above embodiment, the functions of the acquisition unit, the detection unit, the candidate estimation unit, and the identification unit are controlled by the central control unit 1 of the mobile terminal 100 (200), the image acquisition unit 6b, The coordinate detecting unit 6c, the first posture candidate estimating unit 6d (second posture candidate estimating unit 206d), and the first posture specifying unit 6f (second posture specifying unit 206f) are driven. However, the present invention is not limited to this, and a configuration realized by executing a predetermined program by the CPU of the central control unit 1 may be adopted.
That is, a program including an acquisition process routine, a detection process routine, a candidate estimation process routine, and a specific process routine is stored in a program memory that stores the program. Then, the CPU of the central control unit 1 may function as means for sequentially acquiring images including a specific subject imaged by the imaging unit 3 by the acquisition processing routine. Further, the CPU of the central control unit 1 may function as a means for detecting the coordinates of a plurality of points constituting the image area of a specific subject in the acquired image by the detection processing routine. Further, the CPU of the central control unit 1 is caused to function as a means for estimating at least one posture candidate of a specific subject with respect to the imaging unit 3 based on the coordinates of the detected plurality of points by the candidate estimation processing routine. Also good. Further, the CPU of the central control unit 1 may function as a means for specifying any one of the estimated posture candidates as an optimum solution of the posture of the specific subject with respect to the imaging unit 3 by the specifying process routine. .

  Similarly, the first estimation unit, the second estimation unit, the determination unit, and the designation unit may be realized by executing a predetermined program or the like by the CPU of the central control unit 1.

  Furthermore, as a computer-readable medium storing a program for executing each of the above processes, a non-volatile memory such as a flash memory or a portable recording medium such as a CD-ROM is applied in addition to a ROM or a hard disk. Is also possible. A carrier wave is also used as a medium for providing program data via a predetermined communication line.

[Appendix]
Although several embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and equivalents thereof.
The invention described in the scope of claims attached to the application of this application will be added below. The item numbers of the claims described in the appendix are as set forth in the claims attached to the application of this application.
<Claim 1>
Acquisition means for sequentially acquiring images including a specific subject imaged by the imaging unit;
Detecting means for detecting coordinates of a plurality of points constituting the image area of the specific subject in the image acquired by the acquiring means;
Candidate estimating means for estimating at least one posture candidate of the specific subject with respect to the imaging unit based on the coordinates of the plurality of points detected by the detecting means;
Specifying means for specifying any one of the posture candidates estimated by the candidate estimating means as an optimum solution of the posture of the specific subject with respect to the imaging unit;
A subject detection apparatus comprising:
<Claim 2>
The candidate estimating means includes
First estimation means for estimating a first posture candidate of the specific subject with respect to the imaging unit based on the coordinates of the plurality of points detected by the detection means;
Second estimation means for estimating a second posture candidate different from the first posture candidate of the specific subject with respect to the imaging unit based on an estimation result by the first estimation means,
The specifying means is:
The subject detection apparatus according to claim 1, wherein one of the first posture candidate and the second posture candidate is specified as the optimal solution.
<Claim 3>
A determination unit for determining whether the first posture candidate estimated by the first estimation unit is correct according to a predetermined determination criterion;
The subject detection apparatus according to claim 2, wherein the second estimation unit estimates the second posture candidate when the determination unit determines that the first posture candidate is not correct.
<Claim 4>
The specifying means is:
When the determination means determines that the first posture candidate is correct, the first posture candidate is specified as the optimal solution, while the first posture candidate is determined to be incorrect, The subject detection apparatus according to claim 3, wherein the second posture candidate estimated by two estimation means is specified as the optimal solution.
<Claim 5>
Further comprising designation means for designating a temporary posture of the specific subject with respect to the imaging unit in advance;
5. The subject detection apparatus according to claim 3, wherein the determination unit determines whether the first posture candidate is correct based on the provisional posture specified by the specification unit.
<Claim 6>
The determination unit determines whether the first posture candidate is correct based on a change in posture of the specific subject with respect to the imaging unit that is sequentially specified as the optimal solution by the specifying unit. The subject detection device according to claim 3, wherein the subject detection device is a feature.
<Claim 7>
Further comprising designation means for designating a temporary posture of the specific subject with respect to the imaging unit in advance;
The said specifying means specifies the thing substantially agree | coinciding with the temporary attitude | position designated by the said designation | designated means among the several said attitude | position candidates estimated by the said candidate estimation means as the said optimal solution. The subject detection device according to 1.
<Claim 8>
2. The specification unit according to claim 1, wherein the specifying unit sequentially specifies the posture of the specific subject with respect to the imaging unit as the optimal solution, and specifies the optimal solution again based on a change of the posture. The subject detection device described.
<Claim 9>
The subject detection apparatus according to claim 1, wherein the specific subject is a marker.
<Claim 10>
A subject detection method using a subject detection device,
A process of sequentially acquiring images including a specific subject imaged by the imaging unit;
Processing for detecting coordinates of a plurality of points constituting the image area of the specific subject in the acquired image;
A process of estimating at least one posture candidate of the specific subject with respect to the imaging unit based on the detected coordinates of the plurality of points;
Processing for specifying any one of the estimated posture candidates as an optimal solution of the posture of the specific subject with respect to the imaging unit;
A method for detecting a subject, comprising:
<Claim 11>
The computer of the subject detection device
Acquisition means for sequentially acquiring images including a specific subject imaged by the imaging unit;
Detecting means for detecting coordinates of a plurality of points constituting the image area of the specific subject in the image acquired by the acquiring means;
Candidate estimating means for estimating at least one posture candidate of the specific subject with respect to the imaging unit based on the coordinates of the plurality of points detected by the detecting means;
A specifying unit that specifies any one of the posture candidates estimated by the candidate estimation unit as an optimal solution of the posture of the specific subject with respect to the imaging unit;
A program characterized by functioning as

100, 200 Mobile terminal 1 Central control unit 3 Imaging unit 6, 206 Marker detection processing unit 6a Temporary posture designation unit 6b Image acquisition unit 6c Coordinate detection unit 6d First posture candidate estimation unit d1 First estimation unit d2 Second estimation unit 206d Second posture candidate estimation unit 6e Determination unit 6f First posture specification unit 206f Second posture specification unit F Frame image M Marker

Claims (11)

Acquisition means for sequentially acquiring images including a specific subject imaged by the imaging unit;
Detecting means for detecting coordinates of a plurality of points constituting the image area of the specific subject in the image acquired by the acquiring means;
Candidate estimating means for estimating at least one posture candidate of the specific subject with respect to the imaging unit based on the coordinates of the plurality of points detected by the detecting means;
Specifying means for specifying any one of the posture candidates estimated by the candidate estimating means as an optimum solution of the posture of the specific subject with respect to the imaging unit;
A subject detection apparatus comprising: The candidate estimating means includes
First estimation means for estimating a first posture candidate of the specific subject with respect to the imaging unit based on the coordinates of the plurality of points detected by the detection means;
Second estimation means for estimating a second posture candidate different from the first posture candidate of the specific subject with respect to the imaging unit based on an estimation result by the first estimation means,
The specifying means is:
The subject detection apparatus according to claim 1, wherein one of the first posture candidate and the second posture candidate is specified as the optimal solution. A determination unit for determining whether the first posture candidate estimated by the first estimation unit is correct according to a predetermined determination criterion;
The subject detection apparatus according to claim 2, wherein the second estimation unit estimates the second posture candidate when the determination unit determines that the first posture candidate is not correct. The specifying means is:
When the determination means determines that the first posture candidate is correct, the first posture candidate is specified as the optimal solution, while the first posture candidate is determined to be incorrect, The subject detection apparatus according to claim 3, wherein the second posture candidate estimated by two estimation means is specified as the optimal solution. Further comprising designation means for designating a temporary posture of the specific subject with respect to the imaging unit in advance;
5. The subject detection apparatus according to claim 3, wherein the determination unit determines whether the first posture candidate is correct based on the provisional posture specified by the specification unit.   The determination unit determines whether the first posture candidate is correct based on a change in posture of the specific subject with respect to the imaging unit that is sequentially specified as the optimal solution by the specifying unit. The subject detection device according to claim 3, wherein the subject detection device is a feature. Further comprising designation means for designating a temporary posture of the specific subject with respect to the imaging unit in advance;
The said specifying means specifies the thing substantially agree | coinciding with the temporary attitude | position designated by the said designation | designated means among the several said attitude | position candidates estimated by the said candidate estimation means as the said optimal solution. The subject detection device according to 1.   2. The specification unit according to claim 1, wherein the specifying unit sequentially specifies the posture of the specific subject with respect to the imaging unit as the optimal solution, and specifies the optimal solution again based on a change of the posture. The subject detection device described.   The subject detection apparatus according to claim 1, wherein the specific subject is a marker. A subject detection method using a subject detection device,
A process of sequentially acquiring images including a specific subject imaged by the imaging unit;
Processing for detecting coordinates of a plurality of points constituting the image area of the specific subject in the acquired image;
A process of estimating at least one posture candidate of the specific subject with respect to the imaging unit based on the detected coordinates of the plurality of points;
Processing for specifying any one of the estimated posture candidates as an optimal solution of the posture of the specific subject with respect to the imaging unit;
A method for detecting a subject, comprising: The computer of the subject detection device
Acquisition means for sequentially acquiring images including a specific subject imaged by the imaging unit;
Detecting means for detecting coordinates of a plurality of points constituting the image area of the specific subject in the image acquired by the acquiring means;
Candidate estimating means for estimating at least one posture candidate of the specific subject with respect to the imaging unit based on the coordinates of the plurality of points detected by the detecting means;
A specifying unit that specifies any one of the posture candidates estimated by the candidate estimation unit as an optimal solution of the posture of the specific subject with respect to the imaging unit;
A program characterized by functioning as

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