WO2020255232A1 - Data encoding device, data decoding device, data communication system, data communication method, and computer-readable recording medium - Google Patents

Abstract

When encoding or decoding data that indicates an in-plane displacement extracted from an image, the present invention reduces the cost required for transmission and accumulation, while maintaining a sufficient spatial resolution. This data encoding device 20 is provided with: a reference signal generation unit 21 which generates a reference signal, the level of which varies in accordance with stress generated on a specific surface of an object, from a whole surface displacement on the specific surface of the object, which is measured from time series images of the object, and an in-plane displacement in the specific surface of the object, which is measured from the whole surface displacement and the time series images; a regression coefficient calculation unit 22 which calculates, by using the reference signal and the in-plane displacement, regression coefficients that indicate an interlocking degree between time series variations at a level of the reference signal and time series variations in the in-plane displacement; and a data output unit 23 which outputs the reference signal and the regression coefficient as data indicating the in-plane displacement.

Description

Data encoders, data decoders, data communication systems, data communication methods, and computer-readable recording media

The present invention relates to a data encoding device, a data decoding device, a data communication system, and a data communication method for encoding or decoding in-plane displacement data obtained from an image of an object, and further, these. It relates to a computer-readable recording medium on which a program for realizing the program is recorded.

Conventionally, a technique for determining the state of a structure such as a bridge by non-contact has been proposed (see, for example, Patent Document 1). According to such a determination technique, the inspector can inspect the structure without touching the structure. Such a determination technique is particularly useful for structures that are grounded in places that inspectors cannot easily approach.

Patent Document 1 derives an in-plane displacement component of a portion to be determined from an image of a structure such as a bridge as a subject, and determines the state of the structure based on the derived in-plane displacement component. The device is disclosed.

Specifically, the device disclosed in Patent Document 1 first acquires a plurality of images from a visible camera in chronological order. Then, the apparatus disclosed in Patent Document 1 subtracts a component due to the displacement of the entire surface to be determined from the optical flow of the acquired image or the displacement vector field obtained by the image correlation method to obtain the surface. Derivation of the internal displacement component.

Next, the apparatus disclosed in Patent Document 1 obtains the in-plane displacement distribution from the derived in-plane displacement component, and compares the obtained in-plane displacement distribution with the reference in-plane displacement distribution. At this time, if damage such as an opening due to cracks occurs, there will be a difference between the two in-plane distributions. Therefore, the apparatus disclosed in Patent Document 1 detects defects such as cracks from the comparison result.

International Publication No. 2016/152075

By the way, the data of the in-plane displacement component derived by the apparatus disclosed in Patent Document 1 is transmitted to a data server or the like via a network for recording, and is accumulated there. However, the data of the in-plane displacement component thus obtained has a characteristic that the amount of data is very large, and there is a problem that a large cost is required for transmission and storage via the network.

For example, it is assumed that the conditions of the moving image data obtained by photographing the structure are 2048 × 2048 pixels, a frame rate of 80 fps, and a time of 10 seconds. In this case, assuming that displacements in the X and Y directions (32-bit floating point numbers each) are obtained for each pixel coordinate, the amount of in-plane displacement component data is about 26 GB.

Further, conventionally, MPEG has been known as a compression format for moving image data, and it is considered that the cost can be reduced by compressing the in-plane displacement component data using such a compression format. Be done. However, while MPEG is a compression method for efficiently compressing two-dimensional data in time series, the in-plane displacement component data is composed of a floating-point format input signal. Therefore, even if the cost can be reduced, the distortion generated when compressed at a high compression rate may significantly reduce the accuracy in determining the state by damage detection.

It is also possible to reduce the size of the data by using methods such as thinning out (reducing) the resolution, but to a practical level where cost can be reduced while maintaining sufficient spatial resolution when detecting damage. It is difficult to reduce the size of the data.

An example of an object of the present invention can solve the above problem and reduce the cost of transmission and storage while maintaining sufficient spatial resolution in coding or decoding of data indicating in-plane displacement extracted from an image. , A data encoding device, a data decoding device, a data communication system, a data communication method, and a computer-readable recording medium.

In order to achieve the above object, the data encoding device in one aspect of the present invention is
From the total surface displacement of the object on the specific surface measured from the time-series image of the object, and the in-plane displacement of the object on the specific surface measured from the total surface displacement and the time-series image. A reference signal generator that generates a reference signal and whose level changes according to the stress generated on the specific surface of the object.
A regression coefficient calculation unit that calculates a regression coefficient that indicates the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement using the reference signal and the in-plane displacement.
A data output unit that outputs the reference signal and the regression coefficient as data indicating the in-plane displacement.
It is characterized by having.

In order to achieve the above object, the data decoding device in one aspect of the present invention is
It shows the degree of interlocking between the reference signal whose level changes according to the stress generated on the specific surface of the object and the time-series change of the level of the reference signal and the time-series change of the in-plane displacement on the specific surface of the object. Regression coefficient, data acquisition unit and
A data decoding unit that restores the in-plane displacement of the object on a specific surface by using the acquired reference signal and the regression coefficient.
Is equipped with
It is characterized by that.

In order to achieve the above object, the data communication system in one aspect of the present invention includes a data encoding device and a data decoding device.
The data encoding device is
From the total surface displacement of the object on the specific surface measured from the time-series image of the object, and the in-plane displacement of the object on the specific surface measured from the total surface displacement and the time-series image. A reference signal generator that generates a reference signal and whose level changes according to the stress generated on the specific surface of the object.
A regression coefficient calculation unit that calculates a regression coefficient that indicates the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement using the reference signal and the in-plane displacement.
A data output unit that outputs the reference signal and the regression coefficient as data indicating the in-plane displacement is provided.
The data decoding device
It shows the degree of interlocking between the reference signal whose level changes according to the stress generated on the specific surface of the object and the time-series change of the level of the reference signal and the time-series change of the in-plane displacement on the specific surface of the object. Regression coefficient, data acquisition unit and
It includes a data decoding unit that restores the in-plane displacement of the object on a specific surface by using the acquired reference signal and the regression coefficient.
It is characterized by that.

Further, in order to achieve the above object, the data communication method in one aspect of the present invention is a data communication method using a data coding device and a data decoding device.
(A) The entire surface displacement of the object on a specific surface measured from the time-series image of the object by the data encoding device, and the entire surface displacement and the object measured from the time-series image. From the in-plane displacement on the specific surface of the object, the level changes according to the stress generated on the specific surface of the object, the step of generating a reference signal, and
(B) Regression coefficient indicating the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement by the data coding device using the reference signal and the in-plane displacement. To calculate, steps and
(C) A step in which the reference signal and the regression coefficient are output as data indicating the in-plane displacement by the data encoding device.
(D) A reference signal whose level changes according to the stress generated on the specific surface of the object by the data decoding device, and a time-series change in the level of the reference signal and an in-plane displacement of the object on the specific surface. To get the regression coefficient, which indicates the degree of interlocking with the time series change, the step and
(E) A step of restoring the in-plane displacement of the object on a specific surface using the reference signal and the regression coefficient acquired by the data decoding device.
It is characterized by having.

Further, in order to achieve the above object, the first computer-readable recording medium in one aspect of the present invention is
On the computer
(A) Overall surface displacement of the object on a specific surface measured from a time-series image of the object, and in-plane displacement of the object on a specific surface measured from the entire surface displacement and the time-series image. From, to the step of generating a reference signal, the level changes according to the stress generated on the specific surface of the object.
(B) Using the reference signal and the in-plane displacement, a step of calculating a regression coefficient indicating the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement, and
(C) A step of outputting the reference signal and the regression coefficient as data indicating the in-plane displacement.
It is characterized by recording a program including an instruction to execute.

Further, in order to achieve the above object, the second computer-readable recording medium in one aspect of the present invention is
On the computer
(A) A reference signal whose level changes according to the stress generated on the specific surface of the object, and a time-series change in the level of the reference signal and a time-series change in the in-plane displacement on the specific surface of the object. To get the regression coefficient, which indicates the degree, step and
(B) A step of restoring the in-plane displacement of the object on a specific surface using the acquired reference signal and the regression coefficient.
It is characterized by recording a program including an instruction to execute.

As described above, according to the present invention, in coding or decoding of data indicating in-plane displacement extracted from an image, it is possible to reduce the cost of transmission and storage while maintaining sufficient spatial resolution.

FIG. 1 is a block diagram showing a configuration of a data communication system according to an embodiment of the present invention. FIG. 2 is a block diagram showing more specifically the configuration of the data communication system according to the embodiment of the present invention. FIG. 3 is a diagram illustrating a component included in the displacement observed on the image pickup surface of the image pickup apparatus at a certain point when the measurement target area of the object is photographed. FIG. 4 is a diagram simulating the state of the two-dimensional spatial distribution of the displacements (δx _ij , δy _ij ) observed in a specific area on the image of the measurement target area. 5 (a) to 5 (c) are diagrams for explaining the processing performed by the regression coefficient calculation unit in the embodiment of the present invention, respectively. FIG. 6 is a flow chart showing the operation of the data encoding device according to the embodiment of the present invention. FIG. 7 is a flow chart showing the operation of the data decoding device according to the embodiment of the present invention. FIG. 8 is a block diagram showing an example of a computer that realizes the data encoding device or the data decoding device according to the embodiment of the present invention.

(Embodiment)
Hereinafter, the data encoding device, the data decoding device, the data communication system, the data communication method, and the program according to the embodiment of the present invention will be described with reference to FIGS. 1 to 8.

[System configuration]
First, the configuration of the data coding device, the data decoding device, and the data communication system in the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a data communication system according to an embodiment of the present invention.

The data communication system 10 in the present embodiment shown in FIG. 1 is a system for data communication of in-plane displacement data obtained from an image of an object. As shown in FIG. 1, the data communication system 10 includes a data coding device 20 and a data decoding device 30. Further, the data coding device 20 and the data decoding device 30 are connected to each other via a network 40 such as the Internet.

Further, the data coding device 20 shown in FIG. 1 is a device that encodes in-plane displacement data obtained from an image of an object. As shown in FIG. 1, the data coding device 20 includes a reference signal generation unit 21, a regression coefficient calculation unit 22, and a data output unit 23.

Of these, the reference signal generation unit 21 generates a reference signal whose level changes according to the stress generated on the specific surface of the object from the displacement of the entire surface and the displacement in the surface.

Further, the regression coefficient calculation unit 22 calculates the regression coefficient, which indicates the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement, using the reference signal and the in-plane displacement. The data output unit 23 outputs the reference signal and the regression coefficient to the data decoding device 30 as data indicating the in-plane displacement.

Further, the data decoding device 30 shown in FIG. 2 is a device that decodes the data indicating the in-plane displacement output from the data coding device 20. The data decoding device 30 shown in FIG. 2 includes a data acquisition unit 31 and a data decoding unit 32.

The data acquisition unit 31 acquires the reference signal and the regression coefficient output by the data encoding device 20. The data decoding unit 32 restores the in-plane displacement on the specific surface of the object by using the reference signal and the regression coefficient.

As described above, in the present embodiment, the data indicating the in-plane displacement is transmitted after being converted into a reference signal and a regression coefficient, instead of reducing the size of itself. Therefore, according to the present embodiment, it is possible to reduce the cost of transmission and storage while maintaining sufficient spatial resolution in coding or decoding of data indicating in-plane displacement extracted from an image. ..

Next, the configurations and functions of the data encoding device 20, the data decoding device 30, and the data communication system 10 in the present embodiment will be described in more detail with reference to FIGS. 2 to 5. FIG. 2 is a block diagram showing more specifically the configuration of the data communication system according to the embodiment of the present invention.

As shown in FIG. 2, in the present embodiment, the object whose in-plane displacement is measured is the bridge 60, and when the bridge 60 is bent by the load of the vehicle 61 passing through the bridge 60, the bridge The in-plane displacement in the measurement target area set to 60 is measured. Examples of the measurement target area include bridge girders and plate slabs.

Further, as shown in FIG. 2, an imaging device 50 is connected to the data coding device 20. The image pickup device 50 is a camera capable of shooting a moving image, and outputs a time-series image for each frame. Specifically, the image pickup apparatus 50 takes pictures at set intervals and continuously outputs image data of the taken images. In the present embodiment, as shown in FIG. 2, the image pickup apparatus 50 is arranged so that the floor slab (bottom surface), which is the measurement target area of the bridge 60, can be photographed.

Further, as shown in FIG. 2, in the present embodiment, the data coding device 20 is an image data acquisition unit in addition to the reference signal generation unit 21, the regression coefficient calculation unit 22, and the data output unit 23 described above. 24, an overall surface displacement measuring unit 25, an in-plane displacement measuring unit 26, and a storage unit 27 are provided.

When the image data is output from the imaging device 50, the image data acquisition unit 24 acquires the output image data, and transfers the acquired image data to the entire surface displacement measurement unit 25 and the in-plane displacement measurement unit 26. Output.

The entire surface displacement measuring unit 25 measures the displacement of the entire surface on the specific surface of the object from the time-series image of the object. In the present embodiment, the entire surface displacement measuring unit 25 acquires a time-series image output by the imaging device 50, uses an image captured at an arbitrary time as a reference image, and uses the other images as processed images. Then, the entire surface displacement measuring unit 25 describes each point of the region corresponding to the measurement target region on the specific surface in the reference image (hereinafter referred to as “specific region”) in the processed image for each processed image. The displacement is calculated by searching for each corresponding position. The displacement with respect to the specific region for each processed image calculated in this way is the displacement distribution.

Specifically, the entire surface displacement measuring unit 25 searches for a location (coordinate) in the processed image that is most similar to a location (coordinate) in the specific region, and calculates the displacement of the specified location (coordinate). To do. As a method for identifying similar parts, for example, SAD (Sum of Squared Difference), SSD (Sum of Absolute Difference), and NCC (Normalized) are used by using the brightness values of a certain place (coordinates) and the coordinates around it. A method of searching for the position (coordinates) having the highest correlation by using a similarity correlation function such as Cross-Correlation) or ZNCC (Zero-means Normalized Cross-Correlation) can be mentioned.

By repeatedly performing such a calculation process for each coordinate in the specific area, the distribution of displacement with respect to the specific area in the processed image can be obtained. Further, by performing the same processing for each processed image, it is possible to obtain a displacement distribution with respect to a specific region for each processed image. Here, the specific coordinates of the measurement target area are defined as (i, j)), and the calculated displacement is expressed as (δ x _ij , δ y _ij ).

Subsequently, the entire surface displacement measuring unit 25 uses the calculated displacement (δx _ij , δy _ij ) and the imaging information to determine the amount of movement (Δx, Δy) in the surface direction and the amount of movement in the normal direction (Δx, Δy) of the measurement target area. Δz) and is calculated. Further, in the entire surface displacement measuring unit 25, the calculated displacement (δx _ij , δy _ij ) and the amount of movement (Δx, Δy, Δz) are the total surface displacement. Further, the entire surface displacement measuring unit 25 stores the calculated displacement (δx _ij , δy _ij ) and the movement amount (Δx, Δy, Δz) in the storage unit 27 as the entire surface displacement information. Examples of the photographing information include the size of one pixel of the solid-state image sensor in the image pickup device 50, the focal length of the lens, the image pickup distance from the image pickup device 50 to the measurement target area, the shooting frame rate, and the like.

The in-plane displacement measuring unit 26 measures the in-plane displacement of the bridge 60 on a specific surface from the movement amount (Δx, Δy, Δz) calculated by the overall surface displacement measuring unit 25 and the time series image. Here, the in-plane displacement is expressed as (δδx _ij , δδy _ij ).

Subsequently, with reference to FIGS. 3 and 4, the processing in the entire surface displacement measuring unit 25 and the in-plane displacement measuring unit 26 will be specifically described. FIG. 3 is a diagram illustrating a component included in the displacement observed on the image pickup surface of the image pickup apparatus at a certain point when the measurement target area of the object is photographed. Further, in FIG. 3, the bridge 60, which is an object, is loaded by the passing vehicle 61, and as a result, the measurement target area is moved by the amount of movement (Δx, Δy, Δz) in the three-dimensional direction. Shown.

Here, consider a coordinate system having the center of the imaging surface of the imaging device 50, that is, the point corresponding to the imaging center at the intersection of the optical axis of the lens and the imaging surface as the origin. In this coordinate system, consider the displacements (δ x _ij , δ y _ij ) observed at the point A of the coordinates (i, j) on the image pickup surface of the image pickup apparatus 50. The coordinates (i, j) on the imaging surface of the imaging device 50 can be replaced with the coordinates on the captured image.

In the state of FIG. 3, the measurement target area of the bridge 60 has a movement amount (Δx, Δy, Δz) in the horizontal and vertical directions (X, Y directions) and the normal direction (Z direction) on the screen. It has occurred. The measurement target area moves parallel to the image pickup surface of the image pickup apparatus 50 by the amount (Δx, Δy) moved in the horizontal direction and the vertical direction (X, Y direction) in the screen. Further, the image pickup device 50 is approached by the amount (Δz) of the movement in the normal direction (Z direction). Therefore, the imaging distance is shortened by the movement amount Δz.

As a result, as shown in FIG. 3, a displacement δzx _ij due to the movement amount Δz is generated in addition to the displacement δx caused by the movement amount Δx of the measurement target region in the horizontal direction (X direction) with respect to the imaging surface of the imaging device 50. .. Similarly, on the imaging surface of the imaging device 50, in addition to the displacement δy caused by the moving amount Δy of the imaging device 50 in the direction perpendicular to the screen (Y direction), the displacement δzy _ij due to the moving amount Δz also occurs.

Further, when the surface of the measurement target area is deformed due to the load on the bridge 60 (ΔΔX _ij , ΔΔY _ij ), the in-plane displacement (δδx _ij , δδy _ij ) is changed on the imaging surface of the imaging device 50 accordingly. Are also superimposed.

Here, the in-plane displacement (δδ x _ij , δδy _ij ) due to the surface deformation of the measurement target region is such that the surface displacement changes continuously in a healthy region without defects such as cracks. In the region that straddles the cracks, the surface displacement does not change continuously but changes discontinuously. As described above, the surface displacement distribution is different between the healthy region without defects and the region with some defects.

Then, in the measurement target region, all the generated displacements are added up and observed as a composite vector. That is, the displacements (δ x _ij , δ y _ij ) observed at the point A (i, j) can be represented by the following equations 1 and 2 as shown in FIG. 4 described later.

Here, assuming that the imaging distance from the principal point of the lens to the measurement target region is L, the lens focal length of the imaging device 50 is f, and the coordinates from the imaging center are (i, j), the movement of the object 60 in the plane direction. The displacement (δx, δy) associated with (Δx, Δy) and the displacement (δzx _ij , δzy _ij ) associated with the movement in the normal direction (Δz) are represented by the following equations 3 and 4, respectively.

Assuming that all the measurement target regions have the same three-dimensional movement, the displacement (δx, δy) accompanying the movement (Δx, Δy) in the plane direction indicated by the above equations 3 and 4 is the displacement (δx, δy) at the point A. It can be seen that it is constant regardless of the coordinates. It can also be seen that the displacement (δz x _ij , δzy _ij ) accompanying the movement in the normal direction (Δz) increases as the coordinates of the point A move away from the origin. On the other hand, the in-plane displacement (δδ x _ij , δδy _ij ) of the measurement target area shows the distribution of continuous and discontinuous displacement according to the position of defects such as cracks on the surface, regardless of the coordinates of the coordinates of point A. ..

FIG. 4 is a diagram simulating the state of the two-dimensional spatial distribution (hereinafter referred to as the displacement distribution) of the displacements (δx _ij , δy _ij ) observed in a specific area on the image of the measurement target area. is there. As shown in FIG. 4, the displacement (δx _ij , δy _ij ) of each coordinate of the specific region calculated by the entire surface displacement measuring unit 25 is expressed as a displacement vector. In this case, the displacement vector is the displacement (δx, δy) accompanying the movement (Δx, Δy) in the plane direction observed in a uniform direction and magnitude over the entire screen, and the vector group radial from the imaging center of the screen. displacement caused by the movement in the normal direction (Delta] z) observed (δzx _ij, δzy _ij) denoted the deformation plane displacement due to the surface of the measurement target region (δδx _ij, δδy _ij) as a synthesis component for the ..

Next, a method of calculating the displacement (δx, δy) accompanying the movement in the plane direction (Δx, Δy) will be described. As shown in FIG. 4, the displacement (δx, δy) accompanying the movement in the plane direction (Δx, Δy) is basically observed in a uniform direction and size over the entire screen. Therefore, the displacement (δ x _ij , δ y _ij ) calculated by the entire surface displacement measuring unit 25 at each coordinate of the specific region centered on the imaging center is added with plus or minus depending on the direction of displacement, and this is used as the displacement vector. To do. Then, by adding all the displacement vectors at the target coordinates and calculating the average, the displacement (δx, δy) accompanying the movement in the plane direction (Δx, Δy) is calculated.

Next, the method of calculating the displacement vector (δz x _ij , δzy _ij ) accompanying the movement in the normal direction (Δz) will be described. First, consider a state in which only the displacement vectors (δz x _ij , δzy _ij ) that accompany the movement in the normal direction (Δz) occur. If the movement amount Δz of the specific region is constant within the specific region, the magnitude R (i, j) of the vector becomes a value proportional to the distance from the imaging center as shown in Equation 5 below. Further, if the proportionality constant is set as k as shown in the following equation 6, the equation 5 is also expressed as the equation 7.

On the other hand, the displacements (δ x _ij , δ y _ij ) first calculated by the entire surface displacement measuring unit 25 are actually composed of composite vectors (Fig. 4: ultra-thick solid line arrows) as shown in FIG. There is. Then, this combined vector (δx _ij, δy _ij), as can be seen from Figure 4, the displacement vector associated with movement in the normal direction _{(Δz) (δzx ij, δzy} ij) ( 3, 4: Medium solid line (Arrow), displacement vector (δx, δy) due to in-plane movement (Δx, Δy) (Fig. 3, Fig. 4: thick solid line arrow), and in-plane due to surface deformation and displacement of the measurement target area. The displacement (δδ x _ij , δδy _ij ) (Fig. 3, Fig. 4: Fine solid line arrow) is included.

Therefore, the vector obtained by subtracting the displacement vector (δx, δy) accompanying the in-plane movement (Δx, Δy) from this composite vector (δx _ij , δy _ij ) is the movement in the normal direction (Δz). ) Corresponds to the composite vector of the displacement vector (δ z x _ij , δ zy _ij ) and the in-plane displacement (δ δ x _ij , δ δ y _ij ).

Therefore, the composite vector of the displacement vector (δz x _ij , δzy _ijj ) and the in-plane displacement (δδx _ij , δδy _ij ) accompanying the movement (Δz) in the normal direction at a certain coordinate (i, j) is R _mes (i, i, Then, if j), these can be represented by the following equation 8.

Incidentally, the in-plane displacement (δδx _ij, δδy _ij), the displacement vector associated with movement of the plane direction (Δx, Δy) (δx, δy) , and the normal direction displacement vector associated with movement (Delta] z) of (δzx _ij, Compared to δzy _ij ), it can be regarded as sufficiently small. Therefore, when focusing on the displacement vector (δx, δy) associated with the in-plane movement (Δx, Δy) and the displacement vector (δzx _ij , δzy _ij ) associated with the normal movement (Δz), which are the dominant components. , The above number 8 can be expressed as the following number 9.

In this case, R _mes (i, j) at the coordinates (i, j) can be treated as being substantially equal to the displacement vector component (δz x _ij , δzy _ij ) accompanying the movement in the normal direction (Δz). At this time, the displacement vector when the movement amount Δz in the normal direction is given is represented by R (i, j) shown in Equations 6 to 8.

Therefore, the entire surface displacement measuring unit 25 uses the displacement vector magnitude R _mes (i, j) obtained by Eq. 9, and the displacement vector (δz x _ij , δzy _ij ) accompanying the movement in the normal direction (Δz). ) Estimates the rate of enlargement / reduction of the magnitude R (i, j) of the displacement vector. Specifically, the entire surface displacement measuring unit 25 estimates the magnification of R (i, j) by obtaining the proportionality constant k that minimizes the evaluation function E (k) shown in Equation 10 below.

Therefore, the entire surface displacement measuring unit 25 applies the least squares method to the above equation 10 to calculate the proportionality constant k. As the evaluation function E (k), in addition to the sum of squares of the difference between R _mes (i, j) and R (i, j) shown in the above equation 10, the sum of absolute values and the sum of other powers Etc. may be used.

Then, the entire surface displacement measuring unit 25 applies the calculated proportionality constant k to the above equation 7 as a constant indicating the ratio of enlargement / reduction to calculate the movement amount Δz. Then, the entire surface displacement measuring unit applies the calculated Δz, the displacement (δx, δy) accompanying the movement in the surface direction (Δx, Δy), and the imaging information to the above equation 3, thereby increasing the amount of movement Δx. And Δy are also calculated.

Further, the entire surface displacement measuring unit 25 determines the amount of movement of the measurement target area in the surface direction and the amount of movement of the measurement target area in the normal direction for each image taken by the imaging device 50, that is, for each frame of the time series image. Is calculated. Then, the entire surface displacement measuring unit 25 stores the movement amount calculated for each frame of the time-series image in the storage unit 27 as the entire surface displacement information. Further, in this case, the displacement information of the entire surface can be treated as a time-series signal with the time interval of photographing as the sampling interval.

The in-plane displacement measuring unit 26 measures the in-plane displacement on a specific surface of the object from the displacement of the entire surface and the time-series image of the object. In the present embodiment, the in-plane displacement measuring unit 26 moves the measurement target area in the plane direction (Δx, Δy) calculated by the entire surface displacement measuring unit 25, and the movement amount in the normal direction of the measurement target area. Using (Δz), the in-plane displacement (δδx _ij , δδy _ij ) of the measurement target area is calculated from the first calculated displacement (displacement vector (δx _ij , δy _ij )), and the in-plane displacement is calculated. Is performed frame by frame of the time-series image.

According to FIG. 4, the in-plane displacement (δδx _ij, δδy _ij) in order to calculate the the displacement vector calculated by the in-plane displacement measuring unit 26 (δx _ij, δy _ij) from the amount of movement of the measurement target area ( It can be seen that the displacement component generated by (Δx, Δy, Δz) should be subtracted. That is, the in-plane displacement measuring unit 26 calculates the in-plane displacement (δδ x _ij , δδy _ij ) by using the following equations 11 and 12.

Further, the in-plane displacement measuring unit 26 calculates the in-plane displacement (δδx _ij , δδy _ij ) each time the image pickup apparatus 50 takes an image, that is, in chronological order. Then, the in-plane displacement measuring unit 26 stores the in-plane displacement calculated for each frame of the time-series image in the storage unit 27 as the in-plane displacement information. Further, in this case, the in-plane displacement information can be treated as a time-series signal with the shooting time interval as the sampling interval. In addition, in this specification, in-plane displacement information is also referred to as "in-plane displacement signal".

In the present embodiment, the reference signal generation unit 21 calculates the time-series change ε (t) of the strain in the specific direction of the point of interest from the in-plane displacement of the point of interest on the specific surface of the object in the specific direction. A signal indicating the time-series change ε (t) of the calculated distortion is generated as a reference signal.

Specifically, a point of interest is specified in advance in a measurement target area on a specific surface by an operator or the like of the data communication system 10. As shown in FIG. 2, when the object is a bridge 60 and the measurement target area is a floor slab, a point on the floor slab is designated as a point of interest.

When a point of interest is specified, the reference signal generation unit 21 determines a plurality of points (for example, four points) surrounding the point of interest. Here, the area surrounded by each point is referred to as a "local area". Next, the reference signal generation unit 21 acquires in-plane displacement information at each of the determined points from the storage unit 27.

Then, as in the case of the point of interest, the reference signal generation unit 21 uses the acquired in-plane displacement information of each point to determine the length of the local region in the specific direction, as in the case of the point of interest. The rate of change is obtained, and the obtained rate of change is defined as the time-series change ε (t) of the strain.

On the other hand, when the specific direction is not specified in advance, the reference signal generation unit 21 performs singular value decomposition using the acquired in-plane displacement information of each point, thereby performing the singular value decomposition in the direction in which the local region has the largest change. To identify. Then, the reference signal generation unit 21 obtains the rate of change of the length of the local region in the specified direction, and sets the obtained rate of change as the time-series change ε (t) of the strain.

After that, the reference signal generation unit 21 stores the reference signal obtained from the calculated time-series change in distortion in the storage unit 27 as reference signal information.

In the present embodiment, the regression coefficient calculation unit 22 calculates the regression coefficient for each point (i, j) in the measurement target region on the specific surface. The regression coefficient calculation unit 22 first identifies the time-series change of the in-plane displacement from the in-plane displacement information stored in the storage unit 27, and from the reference signal information stored in the storage unit 27, the reference signal Identify time-series changes in levels. Then, the regression coefficient calculation unit 22 is based on the time-series change in the level of the specified reference signal and the time-series change in the in-plane displacement also specified for each point (i, j) in the measurement target region on the specific surface. , Calculate the regression coefficient indicating the degree of interlocking between the two.

Here, the processing by the regression coefficient calculation unit 22 will be described with reference to FIG. 5 (a) to 5 (c) are diagrams for explaining the processing performed by the regression coefficient calculation unit in the embodiment of the present invention, respectively.

Specifically, first, as shown in FIG. 5A, the regression coefficient calculation unit 22 first performs a time-series change in the level of the reference signal and an in-plane displacement (δδ x _ij ,) at a specific point (i, j). δ δ y _ij ) is identified as a time series change. The in-plane displacement is identified at this time, may be either one of the in-plane displacement Derutaderutawai _ij in the in-plane displacement Derutaderutax _ij and y directions in the x-direction may be both. In the former case, one of the in-plane displacements includes, for example, in-plane displacement of the bridge 60 in the longitudinal direction when the object is the bridge 60. In the latter case, the average in-plane displacement of the in-plane displacement Derutaderutawai _ij in the in-plane displacement Derutaderutax _ij and y direction in the x direction may be specified.

Next, as shown in FIG. 5B, the regression coefficient calculation unit 22 performs a reference signal and in-plane displacement for each point (i, j), along the time series, that is, for each frame of the time series image. Compare with. Then, as shown in FIG. 5 (c), the regression coefficient calculation unit 22 shows the relationship between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement for each point (i, j). A straight line is obtained, and the slope is calculated as a regression coefficient. Further, the calculation of the regression line and the calculation of the regression coefficient are performed in each of the x direction and the y direction, and in reality, the regression coefficient in the x direction and the regression coefficient in the y direction are calculated.

In the present embodiment, the data output unit 23 uses the reference signal information stored in the storage unit 27 and the regression coefficient calculated for each point (i, j) as data indicating the in-plane displacement as a network. It is output to the data decoding device 30 via the 40.

In the present embodiment, the data decoding device 30 is constructed by a program on the operating system of a terminal device such as a PC (Personal Computer), a smartphone, or a tablet terminal. The data decoding device 30 is connected to the display device 33 of the terminal device.

In the data decoding device 30, the data acquisition unit 31 acquires the reference signal information output from the data output unit 23 of the data coding device 20 and the regression coefficient calculated for each point (i, j). ..

In the present embodiment, the data decoding unit 32 multiplies the level of the reference signal specified by the reference signal information by the regression coefficient for each point (i, j) along the time series, thereby multiplying the bridge 60. Restore the in-plane displacement in the measurement target area of. Further, the data decoding unit 32 generates image data for displaying the restored in-plane displacement, outputs the generated image data to the display device 33, and displays the in-plane displacement on the screen.

[Device operation]
Next, the operation of the data communication system 10 according to the embodiment of the present invention will be described with reference to FIGS. 6 and 7. In the following, the operations of the data coding device 20 and the data decoding device 30 will be described with reference to FIGS. 1 to 5 as appropriate. Further, in the first embodiment, the data communication method is implemented by operating the data communication system 10, that is, the data coding device 20 and the data decoding device 30. Therefore, the description of the data communication method in the present embodiment will be replaced with the following description of the operation of the data coding device 20 and the data decoding device 30.

First, the operation of the data encoding device 20 will be described with reference to FIG. FIG. 6 is a flow chart showing the operation of the data encoding device according to the embodiment of the present invention.

As shown in FIG. 6, first, when the image data of the time-series image is output from the image pickup apparatus 50, the image data acquisition unit 24 acquires the output image data, and obtains the acquired image data for each frame. The data is output to the entire surface displacement measuring unit 25 and the in-plane displacement measuring unit 26 (step A1).

Next, when the image data of the time-series image is output in step A1, the entire surface displacement measuring unit 25 measures the displacement of the entire surface of the measurement target area of the bridge 60, which is an object, for each frame (step). A2). Further, the entire surface displacement measuring unit 25 stores the measurement result as the entire surface displacement information in the storage unit 27.

Next, the in-plane displacement measuring unit 26 uses the image data of the time-series image output in step A1 and the entire surface displacement measured in step A2, and the bridge 60, which is an object, is used for each frame. The in-plane displacement in the measurement target area of is measured (step A3). Further, the in-plane displacement measuring unit 26 stores the measurement result in the storage unit 27 as in-plane displacement information.

Next, the reference signal generation unit 21 changes its level according to the stress generated on the specific surface of the object from the total surface displacement measured in step A2 and the in-plane displacement measured in step A3. A reference signal is generated (step A4). Further, the reference signal generation unit 21 stores the generated reference signal as reference signal information in the storage unit 27.

Next, the regression coefficient calculation unit 22 uses the reference signal generated in step A4 and the in-plane displacement measured in step A3 for each point (i, j) in the measurement target region on the specific surface. , Calculate a regression coefficient indicating the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement (step A5).

Next, the data output unit 23 uses the reference signal generated in step A4 and the regression coefficient for each point (i, j) calculated in step A5 as data indicating in-plane displacement via the network 40. Then, the data is transmitted to the data decoding device 30 (step A6). By executing step A6, the processing in the data encoding device 20 is completed.

Subsequently, the operation of the data decoding device 30 will be described with reference to FIG. 7. FIG. 7 is a flow chart showing the operation of the data decoding device according to the embodiment of the present invention.

As shown in FIG. 7, first, in the data decoding device 30, the data acquisition unit 31 receives data indicating in-plane displacement transmitted from the data coding device 20, that is, a reference signal and a point (i, j). ) Acquire the regression coefficient for each (step B1).

Next, the data decoding unit 32 restores the in-plane displacement on the specific surface of the object by using the reference signal acquired in step B1 and the regression coefficient for each point (i, j) (step B2).

After that, the data decoding unit 32 generates image data for displaying the restored in-plane displacement, outputs the generated image data to the display device 33, and displays the in-plane displacement on the screen (step B3). ). By executing step B3, the process in the data decoding device 30 is completed.

(Effect in embodiment)
As described above, according to the first embodiment, the amount of data can be reduced without reducing the data itself indicating the in-plane displacement. According to the present embodiment, in coding or decoding of data indicating in-plane displacement extracted from an image, it is possible to reduce the cost of transmission and storage while maintaining sufficient spatial resolution.

Further, in the present embodiment, the regression coefficient for each point (i, j) transmitted as data indicating the in-plane displacement uses an image compression method (JPEC-XR or the like) corresponding to floating-point pixel representation. It can be compressed. In this case, the data indicating the in-plane displacement can be further compressed.

In addition, the reference signal transmitted as data indicating in-plane displacement can be compressed using an audio compression method (MPEG4-ALS, etc.) that supports floating point numbers. In this case as well, the data indicating the in-plane displacement can be further compressed.

[Modification 1]
Next, Modifications 1 to 4 of the embodiment of the present invention will be described. First, in the present modification 1, it is a condition that the entire surface displacement measuring unit 25 measures the displacement of the entire surface in the in-plane direction of the specific surface of the object and the direction of applying the external force applied to the object. .. In the above-described embodiment, the object is the bridge 60, and the external force is applied in the normal direction, so that the above conditions are satisfied.

Then, in the present modification 1, the reference signal generation unit 21 calculates the time-series change D (t) of the total surface displacement in the external force application direction, and refers to the signal indicating the calculated time-series change of the total surface displacement. Generate as a signal. Specifically, the signal generation unit 13 specifies the time-series change of the movement amount (Δz) in the normal direction measured by the whole surface displacement measurement unit 25 from the whole surface displacement information, and the specified movement amount. Let the time-series change D (t) of (Δz) be the reference signal.

According to the first modification, unlike the above-described embodiment, it is not necessary to specify the point of interest and the specific direction, so that the burden on the inspector of the bridge 60 is reduced. In the first modification, the imaging device 50 is sufficiently fixed in a place that is not easily affected by an external force, and the stress fluctuation due to the external force and the displacement of the entire surface in the application direction of the external force are linked. Useful in some cases.

[Modification 2]
In the present modification 2, the reference signal generation unit 21 first calculates the local strain on the specific surface of the object by using the in-plane displacement, and further integrates the local strain on the entire specific surface to integrate the local strain on the entire specific surface of the object. Calculate the time-series change of strain over a specific surface. Then, the reference signal generation unit 21 generates a signal indicating the time-series change of the calculated distortion as a reference signal.

Specifically, the reference signal generation unit 21 obtains the local strain ε (t, i, j) from the local deformation state at the coordinates (i, j) of the measurement target region for each frame of the image data. First, a plurality of points (for example, 4 points) surrounding the coordinates (i, j) are determined. The area surrounded by each point here is also referred to as a "local area".

Next, the reference signal generation unit 21 acquires in-plane displacement information at each of the determined points from the storage unit 17, and performs local singular value decomposition using the in-plane displacement information of each acquired point. Identify the direction of greatest change in the region. Then, the reference signal generation unit 21 obtains the rate of change of the length of the local region in the specified direction, and sets the obtained rate of change as the local strain s (t, i, j).

Subsequently, the reference signal generation unit 21 integrates the local strain s (t, i, j) over the entire measurement target region, calculates the distortion amount S (t) over the entire measurement target region, and calculates it. Let the distorted amount S (t) be the reference signal. In the present modification 2, the reference signal is obtained from the local strain. Therefore, in the present modification 2, when the imaging device 50 is not sufficiently fixed, the stress fluctuation due to the external force and the displacement of the entire surface in the application direction of the external force are linked. It is also useful when the sex is low.

[Modification 3]
In the present modification 3, as in the modification 2, the reference signal generation unit 21 determines a plurality of points (for example, four points) surrounding the coordinates (i, j), and the storage unit 17 determines each of the determined points. Acquire in-plane displacement information. However, in the present modification 3, unlike the modification 2, the reference signal generation unit 21 uses the acquired in-plane displacement information of each point to indicate the singular values σ ₁ and σ ₂ (σ) indicating the local deformation in the local region. ₁ ≧ σ ₂ ) and the singular vector v ₁ are obtained. The singular vector v ₁ here is a left singular vector corresponding to the singular value σ ₁ , but in the present modification 3, it may be determined that other singular vectors are selected.

Next, the reference signal generation unit 21 calculates the local aperture vector v _op (t, i, j) representing the local aperture direction and magnitude in the local region using the equation 13.

Next, the reference signal generation unit 21 performs principal component analysis of the calculated local aperture vector to specify the first principal component. Specifically, the reference signal generation unit 21 takes the distribution of the point cloud by v _op (t, i, j) at time t as an input, and derives the maximum spread direction of the point cloud by principal component analysis. Further, the reference signal generation unit 21 uses S (t) as the standard deviation of the first principal component axis obtained by the principal component analysis, and uses this as the reference signal. In the present modification 3, by using the principal component analysis, a more robust reference signal can be obtained for the noise included in the in-plane displacement.

[Modification example 4]
In the present modification 4, the reference signal generation unit 21 first calculates the local strain s (t, i, j) for each coordinate (i, j), as in the modification 2. Further, the reference signal generation unit 21 also calculates the time-series change D (t) of the displacement of the entire surface in the external force application direction, as in the modification 1. Subsequently, the reference signal generation unit 21 calculates the regression coefficient w (i, j) of the local strain s (t, i, j) and the time series change D (t) for each coordinate (i, j). ..

Subsequently, the reference signal generation unit 21 uses the above equation 1 to represent the local aperture direction and size in the local region, as in the modification 3, the local aperture vector v _op (t, i, j). Is calculated.

Next, the reference signal generation unit 21 multiplies each of the local aperture vectors v _op (t, i, j), which is the first principal component, by the regression coefficient w (i, j) as a weight. Further, the reference signal generation unit 21 performs the same principal component analysis as the modification 3 for the local aperture vector v _op (t, i, j) after the weight multiplication at the time t. Let S (t) be the standard deviation of the first principal component axis obtained by principal component analysis, and use this as the reference signal. In this modification 4, it is possible to obtain a more robust reference signal for noise included in the in-plane displacement by reducing the contribution of the local aperture vector to the principal component analysis at a point where the degree of interlocking with the external force is low. it can.

[program]
The first program in the present embodiment may be any program that causes a computer to execute steps A1 to A6 shown in FIG. By installing this program on a computer and executing it, the data encoding device 20 according to the present embodiment can be realized. In this case, the computer processor functions and processes as a reference signal generation unit 21, a regression coefficient calculation unit 22, a data output unit 23, an image data acquisition unit 24, an overall surface displacement measurement unit 25, and an in-plane displacement measurement unit 26. To do.

Further, the first program in the present embodiment may be executed by a computer system constructed by a plurality of computers. In this case, for example, each computer has a reference signal generation unit 21, a regression coefficient calculation unit 22, a data output unit 23, an image data acquisition unit 24, an overall surface displacement measurement unit 25, and an in-plane displacement measurement unit 26, respectively. It may function as either.

The second program in the present embodiment may be any program that causes the computer to execute steps B1 to B3 shown in FIG. By installing this program on a computer and executing it, the data decoding device 30 according to the present embodiment can be realized. In this case, the computer processor functions as a data acquisition unit 31 and a data decoding unit 32 to perform processing.

Further, the second program in the present embodiment may be executed by a computer system constructed by a plurality of computers. In this case, for example, each computer may function as either a data acquisition unit 31 or a data decoding unit 32, respectively.

Here, the computer that realizes the data encoding device 20 by executing the first program in the present embodiment and the data decoding device 30 by executing the second program in the present embodiment. The computer to be realized will be described with reference to FIG.

FIG. 8 is a block diagram showing an example of a computer that realizes a data encoding device or a data decoding device according to the embodiment of the present invention. As shown in FIG. 8, the computer 110 includes a CPU (CentralProcessingUnit) 111, a main memory 112, a storage device 113, an input interface 114, a display controller 115, a data reader / writer 116, and a communication interface 117. To be equipped with. Each of these parts is connected to each other via a bus 121 so as to be capable of data communication. Further, the computer 110 may include a GPU (Graphics Processing Unit) or an FPGA (Field-Programmable Gate Array) in addition to the CPU 111 or in place of the CPU 111.

The CPU 111 expands the programs (codes) of the present embodiment stored in the storage device 113 into the main memory 112 and executes them in a predetermined order to perform various operations. The main memory 112 is typically a volatile storage device such as a DRAM (Dynamic Random Access Memory). Further, the program according to the present embodiment is provided in a state of being stored in a computer-readable recording medium 120. The program in the present embodiment may be distributed on the Internet connected via the communication interface 117.

Further, specific examples of the storage device 113 include a semiconductor storage device such as a flash memory in addition to a hard disk drive. The input interface 114 mediates data transmission between the CPU 111 and an input device 118 such as a keyboard and mouse. The display controller 115 is connected to the display device 119 and controls the display on the display device 119.

The data reader / writer 116 mediates the data transmission between the CPU 111 and the recording medium 120, reads the program from the recording medium 120, and writes the processing result in the computer 110 to the recording medium 120. The communication interface 117 mediates data transmission between the CPU 111 and another computer.

Specific examples of the recording medium 120 include a general-purpose semiconductor storage device such as CF (CompactFlash (registered trademark)) and SD (SecureDigital), a magnetic recording medium such as a flexible disk, or a CD-. Examples include optical recording media such as ROM (CompactDiskReadOnlyMemory).

The data coding device 20 and the data decoding device 30 in the present embodiment can also be realized by using hardware corresponding to each part instead of the computer in which the program is installed. Further, the data encoding device 20 and the data decoding device 30 may be partially realized by a program and the rest may be realized by hardware.

A part or all of the above-described embodiments can be expressed by the following (Appendix 1) to (Appendix 21), but the present invention is not limited to the following description.

(Appendix 1)
From the total surface displacement of the object on the specific surface measured from the time-series image of the object, and the in-plane displacement of the object on the specific surface measured from the total surface displacement and the time-series image. A reference signal generator that generates a reference signal and whose level changes according to the stress generated on the specific surface of the object.
A regression coefficient calculation unit that calculates a regression coefficient that indicates the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement using the reference signal and the in-plane displacement.
A data output unit that outputs the reference signal and the regression coefficient as data indicating the in-plane displacement.
A data encoding device, characterized in that it comprises.

(Appendix 2)
The data encoding device according to Appendix 1.
An overall surface displacement measuring unit that measures the displacement of the entire surface from the time-series image of the object.
An in-plane displacement measuring unit that measures the in-plane displacement from the entire surface displacement and the time-series image.
Is further equipped,
A data encoding device characterized in that.

(Appendix 3)
The data coding apparatus according to Appendix 1 or 2.
When the in-plane displacement is measured for each point on the specific surface of the object,
The regression coefficient calculation unit calculates the regression coefficient for each point by using the reference signal and the in-plane displacement at the point.
The data output unit outputs the reference signal and the regression coefficient at the point for each point.
A data encoding device characterized in that.

(Appendix 4)
The data encoding device according to any one of Supplementary note 1 to 3.
The reference signal generation unit calculates the time-series change of the strain of the attention point in the specific direction from the in-plane displacement of the point of interest on the specific surface in the specific direction, and calculates the time-series change of the strain. The indicated signal is generated as the reference signal.
A data encoding device characterized in that.

(Appendix 5)
The data encoding device according to any one of Supplementary note 1 to 3.
When the total surface displacement is measured in the in-plane direction of the specific surface of the object and in the direction of applying an external force applied to the object.
The reference signal generation unit calculates the time-series change of the displacement of the entire surface in the application direction, and generates a signal indicating the calculated time-series change of the displacement of the entire surface as the reference signal.
A data encoding device characterized in that.

(Appendix 6)
The data encoding device according to any one of Supplementary note 1 to 3.
The reference signal generation unit calculates the local strain on the specific surface of the object by using the in-plane displacement, and further integrates the local strain on the entire specific surface to integrate the local strain on the entire specific surface of the object. The time-series change of the strain in the above is calculated, and a signal indicating the calculated time-series change of the distortion is generated as the reference signal.
A data encoding device characterized in that.

(Appendix 7)
It shows the degree of interlocking between the reference signal whose level changes according to the stress generated on the specific surface of the object and the time-series change of the level of the reference signal and the time-series change of the in-plane displacement on the specific surface of the object. Regression coefficient, data acquisition unit and
A data decoding unit that restores the in-plane displacement of the object on a specific surface by using the acquired reference signal and the regression coefficient.
Is equipped with
A data decoding device characterized in that.

(Appendix 8)
Equipped with a data encoding device and a data decoding device
The data encoding device is
From the total surface displacement of the object on the specific surface measured from the time-series image of the object, and the in-plane displacement of the object on the specific surface measured from the total surface displacement and the time-series image. A reference signal generator that generates a reference signal and whose level changes according to the stress generated on the specific surface of the object.
A regression coefficient calculation unit that calculates a regression coefficient that indicates the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement using the reference signal and the in-plane displacement.
A data output unit that outputs the reference signal and the regression coefficient as data indicating the in-plane displacement is provided.
The data decoding device
It shows the degree of interlocking between the reference signal whose level changes according to the stress generated on the specific surface of the object and the time-series change of the level of the reference signal and the time-series change of the in-plane displacement on the specific surface of the object. Regression coefficient, data acquisition unit and
It includes a data decoding unit that restores the in-plane displacement of the object on a specific surface by using the acquired reference signal and the regression coefficient.
A data communication system characterized by that.

(Appendix 9)
A data communication method using a data encoding device and a data decoding device.
(A) The entire surface displacement of the object on a specific surface measured from the time-series image of the object by the data encoding device, and the entire surface displacement and the object measured from the time-series image. From the in-plane displacement on the specific surface of the object, the level changes according to the stress generated on the specific surface of the object, the step of generating a reference signal, and
(B) Regression coefficient indicating the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement by the data coding device using the reference signal and the in-plane displacement. To calculate, steps and
(C) A step in which the reference signal and the regression coefficient are output as data indicating the in-plane displacement by the data encoding device.
(D) A reference signal whose level changes according to the stress generated on the specific surface of the object by the data decoding device, and a time-series change in the level of the reference signal and an in-plane displacement of the object on the specific surface. To get the regression coefficient, which indicates the degree of interlocking with the time series change, the step and
(E) A step of restoring the in-plane displacement of the object on a specific surface using the reference signal and the regression coefficient acquired by the data decoding device.
A data communication method characterized by having.

(Appendix 10)
The data communication method described in Appendix 9
(F) A step of measuring the displacement of the entire surface from the time-series image of the object by the data encoding device.
(G) A step of measuring the in-plane displacement from the entire surface displacement and the time-series image by the data encoding device.
Further have,
A data communication method characterized by that.

(Appendix 11)
The data communication method according to Appendix 9 or 10.
When the in-plane displacement is measured for each point on the specific surface of the object,
In the step (b), the regression coefficient is calculated for each point by using the reference signal and the in-plane displacement at the point.
In the step (c), the reference signal and the regression coefficient at the point are output for each point.
A data communication method characterized by that.

(Appendix 12)
The data communication method according to any one of Appendix 9 to 11.
In the step (a), the time-series change of the strain of the attention point in the specific direction is calculated from the in-plane displacement of the point of interest on the specific surface in the specific direction, and the calculated time-series change of the strain is calculated. Is generated as the reference signal.
A data communication method characterized by that.

(Appendix 13)
The data communication method according to any one of Appendix 9 to 11.
When the total surface displacement is measured in the in-plane direction of the specific surface of the object and in the direction of applying an external force applied to the object.
In the step (a), the time-series change of the displacement of the entire surface in the application direction is calculated, and a signal indicating the calculated time-series change of the displacement of the entire surface is generated as the reference signal.
A data communication method characterized by that.

(Appendix 14)
The data communication method according to any one of Appendix 9 to 11.
In the step (a), the local strain on the specific surface of the object is calculated by using the in-plane displacement, and the local strain is integrated over the entire specific surface to calculate the local strain on the specific surface of the object. The time-series change of the distortion in the whole is calculated, and the signal indicating the calculated time-series change of the distortion is generated as the reference signal.
A data communication method characterized by that.

(Appendix 15)
On the computer
(A) Overall surface displacement of the object on a specific surface measured from a time-series image of the object, and in-plane displacement of the object on a specific surface measured from the entire surface displacement and the time-series image. From, to the step of generating a reference signal, the level changes according to the stress generated on the specific surface of the object.
(B) Using the reference signal and the in-plane displacement, a step of calculating a regression coefficient indicating the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement, and
(C) A step of outputting the reference signal and the regression coefficient as data indicating the in-plane displacement, and
A computer-readable recording medium on which the program is recorded, including instructions to execute.

(Appendix 16)
The computer-readable recording medium according to Appendix 15.
The program is on the computer
(D) A step of measuring the displacement of the entire surface from the time-series image of the object, and
(E) A step of measuring the in-plane displacement from the entire surface displacement and the time-series image.
Including further instructions to execute,
A computer-readable recording medium characterized by that.

(Appendix 17)
A computer-readable recording medium according to Appendix 15 or 16.
When the in-plane displacement is measured for each point on the specific surface of the object,
In the step (b), the regression coefficient is calculated for each point by using the reference signal and the in-plane displacement at the point.
In the step (c), the reference signal and the regression coefficient at the point are output for each point.
A computer-readable recording medium characterized by that.

(Appendix 18)
A computer-readable recording medium according to any one of Appendix 15 to 17.
In the step (a), the time-series change of the strain of the attention point in the specific direction is calculated from the in-plane displacement of the point of interest on the specific surface in the specific direction, and the calculated time-series change of the strain is calculated. Is generated as the reference signal.
A computer-readable recording medium characterized by that.

(Appendix 19)
A computer-readable recording medium according to any one of Appendix 15 to 17.
When the total surface displacement is measured in the in-plane direction of the specific surface of the object and in the direction of applying an external force applied to the object.
In the step (a), the time-series change of the total surface displacement in the application direction is calculated, and a signal indicating the calculated time-series change of the total surface displacement is generated as the reference signal.
A computer-readable recording medium characterized by that.

(Appendix 20)
A computer-readable recording medium according to any one of Appendix 15 to 17.
In the step (a), the local strain on the specific surface of the object is calculated by using the in-plane displacement, and the local strain is integrated over the entire specific surface to calculate the local strain on the specific surface of the object. The time-series change of the distortion in the whole is calculated, and the signal indicating the calculated time-series change of the distortion is generated as the reference signal.
A computer-readable recording medium characterized by that.

(Appendix 21)
On the computer
(A) A reference signal whose level changes according to the stress generated on the specific surface of the object, and a time-series change in the level of the reference signal and a time-series change in the in-plane displacement on the specific surface of the object. To get the regression coefficient, which indicates the degree, step and
(B) A step of restoring the in-plane displacement of the object on a specific surface using the acquired reference signal and the regression coefficient.
A computer-readable recording medium on which the program is recorded, including instructions to execute.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made within the scope of the present invention in terms of the structure and details of the present invention.

As described above, according to the present invention, in coding or decoding of data indicating in-plane displacement extracted from an image, it is possible to reduce the cost of transmission and storage while maintaining sufficient spatial resolution. The present invention is useful for a system for determining the state of a structure such as a bridge from an image.

10 Data communication system 20 Data coding device 21 Reference signal generation unit 22 Regression coefficient calculation unit 23 Data output unit 24 Image data acquisition unit 25 Overall plane displacement measurement unit 26 In-plane displacement measurement unit 27 Storage unit 30 Data decoding device 31 Data acquisition Part 32 Data decoding part 33 Display device 40 Network 50 Imaging device 60 Bridge 110 Computer 111 CPU
112 Main memory 113 Storage device 114 Input interface 115 Display controller 116 Data reader / writer 117 Communication interface 118 Input device 119 Display device 120 Recording medium 121 Bus

Claims (21)

1. From the total surface displacement of the object on the specific surface measured from the time-series image of the object, and the in-plane displacement of the object on the specific surface measured from the total surface displacement and the time-series image. A reference signal generating means that generates a reference signal whose level changes according to the stress generated on the specific surface of the object.
   A regression coefficient calculating means for calculating a regression coefficient, which indicates the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement using the reference signal and the in-plane displacement.
   A data output means that outputs the reference signal and the regression coefficient as data indicating the in-plane displacement.
   A data encoding device, characterized in that it comprises.
2. The data encoding device according to claim 1.
   An overall surface displacement measuring means that measures the displacement of the entire surface from the time-series image of the object.
   An in-plane displacement measuring means that measures the in-plane displacement from the entire surface displacement and the time-series image.
   Is further equipped,
   A data encoding device characterized in that.
3. The data encoding device according to claim 1 or 2.
   When the in-plane displacement is measured for each point on the specific surface of the object,
   The regression coefficient calculating means calculates the regression coefficient for each point by using the reference signal and the in-plane displacement at the point.
   The data output means outputs the reference signal and the regression coefficient at the point for each point.
   A data encoding device characterized in that.
4. The data encoding device according to any one of claims 1 to 3.
   The reference signal generating means calculates the time-series change of the strain of the attention point in the specific direction from the in-plane displacement of the point of interest on the specific surface in the specific direction, and calculates the time-series change of the strain. The indicated signal is generated as the reference signal.
   A data encoding device characterized in that.
5. The data encoding device according to any one of claims 1 to 3.
   When the total surface displacement is measured in the in-plane direction of the specific surface of the object and in the direction of applying an external force applied to the object.
   The reference signal generating means calculates the time-series change of the displacement of the entire surface in the application direction, and generates a signal indicating the calculated time-series change of the displacement of the entire surface as the reference signal.
   A data encoding device characterized in that.
6. The data encoding device according to any one of claims 1 to 3.
   The reference signal generating means calculates the local strain on the specific surface of the object by using the in-plane displacement, and further integrates the local strain on the entire specific surface to integrate the local strain on the entire specific surface of the object. The time-series change of the strain in the above is calculated, and a signal indicating the calculated time-series change of the distortion is generated as the reference signal.
   A data encoding device characterized in that.
7. It shows the degree of interlocking between the reference signal whose level changes according to the stress generated on the specific surface of the object and the time-series change of the level of the reference signal and the time-series change of the in-plane displacement on the specific surface of the object. Regression coefficient, data acquisition means, and
   A data decoding means that restores the in-plane displacement of the object on a specific surface using the acquired reference signal and the regression coefficient.
   Is equipped with
   A data decoding device characterized in that.
8. Equipped with a data encoding device and a data decoding device
   The data encoding device is
   From the total surface displacement of the object on the specific surface measured from the time-series image of the object, and the in-plane displacement of the object on the specific surface measured from the total surface displacement and the time-series image. A reference signal generating means that generates a reference signal whose level changes according to the stress generated on the specific surface of the object.
   A regression coefficient calculating means for calculating a regression coefficient, which indicates the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement using the reference signal and the in-plane displacement.
   A data output means for outputting the reference signal and the regression coefficient as data indicating the in-plane displacement is provided.
   The data decoding device
   It shows the degree of interlocking between the reference signal whose level changes according to the stress generated on the specific surface of the object and the time-series change of the level of the reference signal and the time-series change of the in-plane displacement on the specific surface of the object. Regression coefficient, data acquisition means, and
   A data decoding means that restores an in-plane displacement on a specific surface of the object by using the acquired reference signal and the regression coefficient is provided.
   A data communication system characterized by that.
9. A data communication method using a data encoding device and a data decoding device.
   (A) The entire surface displacement of the object on a specific surface measured from the time-series image of the object by the data encoding device, and the entire surface displacement and the object measured from the time-series image. From the in-plane displacement on the specific surface of the object, generate a reference signal whose level changes according to the stress generated on the specific surface of the object.
   (B) Regression coefficient indicating the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement by the data coding device using the reference signal and the in-plane displacement. Is calculated and
   (C) The data encoding device outputs the reference signal and the regression coefficient as data indicating the in-plane displacement.
   (D) A reference signal whose level changes according to the stress generated on the specific surface of the object by the data decoding device, and a time-series change in the level of the reference signal and an in-plane displacement of the object on the specific surface. Obtain the regression coefficient, which indicates the degree of interlocking with the time series change,
   (E) Using the reference signal and the regression coefficient acquired by the data decoding device, the in-plane displacement of the object on a specific surface is restored.
   A data communication method characterized by that.
10. The data communication method according to claim 9, further.
    (F) The data coding device measures the displacement of the entire surface from the time-series image of the object.
    (G) The data coding device measures the in-plane displacement from the entire surface displacement and the time-series image.
    A data communication method characterized by that.
11. The data communication method according to claim 9 or 10.
    When the in-plane displacement is measured for each point on the specific surface of the object,
    In (b), the regression coefficient is calculated for each of the points by using the reference signal and the in-plane displacement at the point.
    In the above (c), the reference signal and the regression coefficient at the point are output for each point.
    A data communication method characterized by that.
12. The data communication method according to any one of claims 9 to 11.
    In (a), the time-series change of the strain of the attention point in the specific direction is calculated from the in-plane displacement of the point of interest on the specific surface in the specific direction, and the calculated time-series change of the strain is shown. Generate a signal as the reference signal,
    A data communication method characterized by that.
13. The data communication method according to any one of claims 9 to 11.
    When the total surface displacement is measured in the in-plane direction of the specific surface of the object and in the direction of applying an external force applied to the object.
    In (a), the time-series change of the total surface displacement in the application direction is calculated, and a signal indicating the calculated time-series change of the total surface displacement is generated as the reference signal.
    A data communication method characterized by that.
14. The data communication method according to any one of claims 9 to 11.
    In (a), the in-plane displacement is used to calculate the local strain on the specific surface of the object, and the local strain is integrated for the entire specific surface to be integrated on the entire specific surface of the object. A time-series change in strain is calculated, and a signal indicating the calculated time-series change in distortion is generated as the reference signal.
    A data communication method characterized by that.
15. On the computer
    (A) Overall surface displacement of the object on a specific surface measured from a time-series image of the object, and in-plane displacement of the object on a specific surface measured from the entire surface displacement and the time-series image. From, to the step of generating a reference signal, the level changes according to the stress generated on the specific surface of the object.
    (B) Using the reference signal and the in-plane displacement, a step of calculating a regression coefficient indicating the degree of interlocking between the time-series change in the level of the reference signal and the time-series change in the in-plane displacement, and
    (C) A step of outputting the reference signal and the regression coefficient as data indicating the in-plane displacement, and
    A computer-readable recording medium on which the program is recorded, including instructions to execute.
16. The computer-readable recording medium according to claim 15.
    The program is on the computer
    (D) A step of measuring the displacement of the entire surface from the time-series image of the object, and
    (E) A step of measuring the in-plane displacement from the entire surface displacement and the time-series image.
    Including further instructions to execute,
    A computer-readable recording medium characterized by that.
17. A computer-readable recording medium according to claim 15 or 16.
    When the in-plane displacement is measured for each point on the specific surface of the object,
    In the step (b), the regression coefficient is calculated for each point by using the reference signal and the in-plane displacement at the point.
    In the step (c), the reference signal and the regression coefficient at the point are output for each point.
    A computer-readable recording medium characterized by that.
18. A computer-readable recording medium according to any one of claims 15 to 17.
    In the step (a), the time-series change of the strain of the attention point in the specific direction is calculated from the in-plane displacement of the point of interest on the specific surface in the specific direction, and the calculated time-series change of the strain is calculated. Is generated as the reference signal.
    A computer-readable recording medium characterized by that.
19. A computer-readable recording medium according to any one of claims 15 to 17.
    When the total surface displacement is measured in the in-plane direction of the specific surface of the object and in the direction of applying an external force applied to the object.
    In the step (a), the time-series change of the total surface displacement in the application direction is calculated, and a signal indicating the calculated time-series change of the total surface displacement is generated as the reference signal.
    A computer-readable recording medium characterized by that.
20. A computer-readable recording medium according to any one of claims 15 to 17.
    In the step (a), the local strain on the specific surface of the object is calculated by using the in-plane displacement, and the local strain is integrated over the entire specific surface to calculate the local strain on the specific surface of the object. The time-series change of the distortion in the whole is calculated, and the signal indicating the calculated time-series change of the distortion is generated as the reference signal.
    A computer-readable recording medium characterized by that.
21. On the computer
    (A) A reference signal whose level changes according to the stress generated on the specific surface of the object, and a time-series change in the level of the reference signal and a time-series change in the in-plane displacement on the specific surface of the object. To get the regression coefficient, which indicates the degree, step and
    (B) A step of restoring the in-plane displacement of the object on a specific surface using the acquired reference signal and the regression coefficient.
    A computer-readable recording medium on which the program is recorded, including instructions to execute.

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