JP2002010297A - Stereo imaging system - Google Patents

Abstract

(57) [Summary] [Problem] To easily obtain a stable, highly reliable, and accurate stereo image when performing three-dimensional measurement with a normal camera. SOLUTION: A photographing unit 10 has a camera for photographing an image and a prism. Furthermore, the imaging unit 10 can be made movable by a driving unit. As the measuring unit 100, a total station or the like as a surveying instrument is used.
The position data (measured value) is measured with the entire circumference prism 2 on 0 as a collimation. The signal forming unit 20 includes the photographing unit 10
A timing signal indicating a position measurement command is output to the measurement unit 100 in accordance with the photographing timing from. The image data storage unit 30 stores the image data photographed by the camera of the photographing unit 10 and the position data measured by the measuring unit 100 in association with each other. In addition, the signal processing unit 200 performs three-dimensional measurement and analysis based on image data and position data obtained by stereo shooting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stereo image photographing system, and more particularly to a stereo image photographing system capable of easily obtaining information and measurement data necessary for obtaining three-dimensional data from a stereo image. is there.

[0002]

2. Description of the Related Art In recent years, a line drawing drawing of a measurement site has been created by a combination of a surveying instrument typified by an electronic flat plate and a portable computer. In such a conventional electronic flat plate, drawing is performed by drawing a line drawing on a portable computer using a surveying instrument such as a total station or a GPS. When plotting the measurement site, the user plots while observing the current situation at the site, or photographs separately, and plots at the office while watching them. Further, in aerial photography and the like, plotting is performed using an analytical plotter or the like from an image that has been photographed in stereo. In ground photogrammetry, when performing three-dimensional measurement from stereo images, conventionally, shooting, analysis, and measurement have been performed using a stereo camera in which the base line length and the direction of the camera are strictly fixed.

[0003]

However, in the prior art, the stereo camera has a fixed base line length and the like, and the photographing range and accuracy (object) are limited. Conventionally, when performing measurement without fixing a base line or the like, when performing stereo photography and performing three-dimensional analysis, even if two images are overlapped and photographed, the image can be subjected to stereo analysis. It was difficult. That is, in most cases, the image cannot be analyzed, or even if the image can be analyzed, the image is unstable, has low accuracy, is extremely low in reliability. In particular, when a camera is mounted on a balloon, a car, or another moving body for photographing, it is very difficult to obtain a highly reliable and analyzable image.

[0004]

According to the present invention, there is provided a movable photographing section on which a photographing camera and a reflection member are mounted, and a photographing section which is photographed when photographed by the camera of the photographing section. A signal forming unit for forming a timing signal indicating timing, and a signal forming unit that is placed at a position distant from the photographing unit and emits measurement light toward a reflecting member of the photographing unit in accordance with the timing signal from the signal forming unit. And a measuring unit for measuring the position of the photographing unit based on the reflected light reflected from the reflecting member.

[0005]

Embodiments of the present invention will be described below. FIG. 1 shows a configuration diagram of a first embodiment of a stereo image capturing system. In this embodiment, an image capturing unit 10, a signal forming unit 20, a measuring unit 100, an image data storage unit 30, and a signal processing unit 200 are provided.

[0006] The photographing unit 10 has a camera for photographing an image and a prism. Furthermore, the imaging unit 10 can be made movable by a driving unit. As the measuring unit 100, a total station or the like as a surveying instrument is used.
The position data (measurement value) is measured using the upper circumferential prism 2 as a collimation. The signal forming unit 20 outputs a timing signal indicating a position measurement command to the measuring unit 100 in accordance with the photographing timing from the photographing unit 10. The image data storage unit 30 stores the image data photographed by the camera of the photographing unit 10 and the position data measured by the measuring unit 100 in association with each other. In addition, the signal processing unit 200 performs three-dimensional measurement and analysis based on image data and position data obtained by stereo shooting.

FIG. 2 shows a configuration diagram of the photographing unit 10. As the camera 1, a commercially available film camera, digital camera, measurement camera, or the like is used. A large number of prisms are mounted in each direction so that the position can be measured by the measuring unit 100 from anywhere.

FIG. 3 shows a configuration diagram of the drive unit. For example, as shown in FIG. 3A, the driving unit 90 is attached to a car, a caterpillar-like thing, a balloon shown in FIG. can do. Further, the camera 1 of the photographing unit 10 may be provided with a photographing posture position correcting unit as described later, and the obtained acceleration and angular velocity may be cumulatively calculated using a gyro sensor or an inclinometer used there.

[0009] At least a photographing unit 10 is mounted on a platform for photographing.
An image data storage unit 30, a signal processing unit 200, and the like can be mounted. Signals such as a position for a measurement command and measurement data are transmitted and received between the platform and the measurement unit 100 by transceivers provided respectively. These transceivers are attached to the imaging unit 10, the signal forming unit 20, the image data storage unit 30, and other appropriate positions. The transmitter / receiver can use an appropriate wireless or wired transmission method in addition to transmission by optical communication using an optical transmitter / receiver.

As an example of mounting each component, for example, when a component other than the measuring unit 100 is mounted on a platform, a timing signal and measured position data are transmitted and received between the platform and the measuring unit 100 by a transceiver. Transmitted. Further, as another example, the imaging unit 10, the driving unit 90, the movement control unit 80, the image data storage unit 30, and the signal processing unit 200 are mounted on the platform, and the imaging control unit 5
0, the photographing position calculating unit 40 and the condition setting unit 70
It may be mounted on the 0 side. In this case, a timing signal, measured position data, and a control signal of the movement control unit 80 are transmitted between the platform and the measurement unit by the transceiver. Further, as another example, an appropriate component may be mounted as a block other than the platform and the measuring unit 100 side. In this case, for example, the imaging unit 10, the driving unit 90, and the movement control unit 80 are provided on the platform, and the imaging control unit 50 and the imaging position calculation unit 4 are provided on other blocks.
0, a condition setting unit 70, an image data storage unit 30, and a signal processing unit 200 can also be mounted.

FIG. 4 is an explanatory view showing the state of measurement.
As shown in this figure, the photographing unit 10 performs photographing from at least two places to perform stereo photographing. And
Each of the photographing positions is measured by the surveying instrument of the measuring unit 100 by using the full-circumferential prism 2 mounted on the photographing unit 10. In addition, if at least one reference point is arranged on the measurement target, the positional relationship between the camera position and the imaging unit 10 and the measurement unit 100 up to the target can be accurately measured.

Next, the operation of manual measurement will be described with reference to a flowchart. FIG. 5 is a flowchart of the basic measurement. First, as shown in FIG. 4, for example, the imaging unit 10 is placed at a predetermined position with respect to the measurement target 5 (S10). This position is roughly determined in advance from necessary accuracy and various conditions of the photographing camera (lens, pixel size, etc.). The measuring unit 100 is connected to the entire circumference prism 2 of the photographing unit 10.
Is installed at a position where collimation is possible (S20). In this case, since the imaging unit 10 moves to a plurality of positions (two or more positions),
These are the places where you can collimate. For example, in FIG. 4, the position is the position of the imaging units 10 and 10 ′. Next, the user presses the shutter to take a picture (S30). At this time, in response to the photographing from the photographing unit 10, the signal forming unit 20 forms a timing signal indicating the photographing timing. The position of the photographing unit 10 is determined in accordance with the timing signal from the signal forming unit 20 by the measuring unit 100.
(S40). To the next shooting position the shooting unit 10
Is moved (S50). Here, the next shooting position is shown in FIG.
As shown in the figure, a position 10 'at which captured images capable of performing stereo imaging are overlapped is set. When the platform is moved, an image is taken (S60). At this time, the signal forming unit 20 forms a timing signal indicating a shooting timing. The position of the photographing unit 10 'is measured by the measuring unit 100 according to the timing signal from the signal forming unit 20 (S70). If the photographing is to be performed further, the camera moves to the next photographing position (S80). The subsequent processing is from S50 to S80.
Is the same as

If the photographing is completed, the photographed image data and the photographing position data are transferred to the signal processing unit 200, and the signal processing unit 200 performs three-dimensional coordinate measurement based on these data (S90). Note that the three-dimensional coordinate measurement can be accurately calculated if the orientation and posture of the camera are in an ideal state.
Even if the image is not in the ideal state, the photographing position data for these images becomes the initial value at the time of mutual orientation, and by using this data, the subsequent analysis can be performed stably.

FIG. 6 shows a detailed flow chart of the position measurement of the photographing unit 10 in steps S40 and S70 in the flow chart of the basic measurement. When the photographing is performed in step S30 or S60 in FIG. 5, a timing signal is transmitted from the platform to the measuring unit 100 in synchronization with the photographing timing (S41). Next, the photographing unit 10
Is measured by the measuring unit 100 (S45). That is, the measuring unit 100 that has received the position measurement command signal,
The collimating prism 2 of the photographing unit 10 is automatically collimated and the position is measured. After performing the position measurement, the measurement unit 100 sends the measurement position data to the platform side (S46). The image data storage unit 30 receives the measurement position data and stores it in association with the photographed image data (S48).

FIG. 7 is a configuration diagram of a second embodiment of the stereo image photographing system. In this embodiment, a photographing unit 10, a signal forming unit 20, an image data storage unit 30, a signal processing unit 200, a measuring unit 100, a condition setting unit 70, a photographing position calculating unit 40, a photographing control unit 50, a movement control unit 80 , A driving unit 90.

The signal forming section 20 has a measuring section 100 and a photographing control section 50 in accordance with the photographing timing from the photographing section 10.
And outputs a timing signal. The condition setting unit 70 sets shooting conditions such as a shooting range, accuracy, and a camera standard value. The shooting position calculation unit 40 calculates an appropriate shooting position based on the shooting target range and the required accuracy set by the condition setting unit 70 and shooting conditions such as a camera and a lens. Also, based on the preliminary measurement result of the measurement unit 100, the planned shooting position is calculated,
decide. The photographing control unit 50 moves so that the position data (measured value) indicating the position of the photographing unit 10 measured by the measuring unit 100 and the photographing position data calculated by the photographing position calculating unit 40 match or substantially match. Control unit 80 and drive unit 9
The photographing unit 10 is moved by 0. When the measured position data and the calculated photographing position data match or substantially coincide with each other, an audible or visible display is provided to the operator of the photographing unit 10. The audible or visible display can be performed by an appropriate display device with a platform such as the imaging control unit 50 and the imaging unit 10, for example. Further, the imaging control unit 50 receives a timing signal from the signal forming unit 20 at an imaging timing, and thereby provides position data (measured value) to the image data storage unit 30. At this time, the image data captured from the image capturing unit 10 to the image data storage unit 30 is stored. The movement control unit 80 gives the driving unit 90 the amount of movement of the imaging unit 10. The drive unit 90 enables the imaging unit 10 to move. Other components are the same as those in FIG.

Next, the operation of automatic measurement will be described with reference to a flowchart. FIG. 8 is a flowchart of the semi-automatic measurement. FIG. 9 is an explanatory diagram of a photographing position by semi-automatic measurement. First, the measurement unit 100 and the platform (imaging unit 10) are installed (S100). The measurement unit 100 is installed at a position where the imaging position of the imaging unit 10 can be seen with respect to the measurement target and is not in the way. For example,
The position is indicated by the measuring unit 100 in FIG. In addition, it is more efficient if it is located at the approximate shooting start position. Next, a measurement range (reference position) of an object to be measured, for example, positions a and b in FIG. 9 are measured by the measurement unit 100 (S11).
0). Further, the position of the all-round prism 2 of the photographing unit 10 is measured by the measuring unit 100 (S110). Then, the measurement unit 100 transfers these measurement data to the imaging control unit 50. The condition setting unit 70 sets shooting condition data related to the shooting target in the shooting position calculation unit 40 (S120). The parameters set here are the angle of view θ of the lens, the focal length f, the pixel pitch δp of the digital camera, and the required precision δx in the plane direction.
y, depth direction required accuracy δz, and the like. The shooting position calculation unit 40 calculates shooting position data based on these conditions (S130). Here, the calculation of the shooting position data will be described. For simplicity, it is assumed that the digital camera is parallel to the measurement object. The photographing position calculating unit 40 calculates the photographing position based on the pixel size δp of the digital camera attached to the photographing unit 10, the focal length f of the lens, the angle of view θ, and the required accuracy set in step S120.

For example, assuming that the required accuracy in the plane direction of the object to be measured is δxy, the photographing distance H is: H = δxy × f / δp If the depth direction is δz, the base line length B is: B = H × H × δp / ( f × δz) The photographing range R is calculated by R = 2Htan (θ / 2). The overlap range O is O = RB.

From these, the number of photographed images is n + 1 if n = area / O remainder 0. Therefore, the entire shooting range is: if remainder = 0, all area = O × n + 2B if remainder ≠ 0, all area = O × (n + 1) + 2B The measurement positions a and b are all set as overlapping areas so that I can decide. When the remainder is ≠ 0, the expression is not limited. Also, the overlapping method is not limited to this. Note that in steps S120 and S130, if the shooting range is known in advance, conditions may be set in advance in steps before this step and roughly calculated. In addition, when it is desired to select a lens or a camera based on necessary accuracy, on-site conditions, and the like, optimum conditions are determined and determined from these conditions before the on-site work.

Returning to the flowchart, the description will be continued. When the photographing position data is calculated in step S130, the photographing control unit 50 compares the previously measured position data of the platform (photographing unit 10) with the photographing position data calculated by the photographing position calculating unit 40 (S140). The photographing control unit 50 may display the position data and the photographing position data, and furthermore, if they coincide or substantially coincide with each other, may display that effect. If they match or substantially match, the photographing signal is determined to be appropriate (OK), and step S1 is performed.
Go to 80. If not, the process proceeds to the next step S145. In step S145, the imaging control unit 50 calculates the displacement amount (movement amount) between the measured position data (measured value) of the platform including the imaging unit 10 and the planned imaging position calculated by the imaging position calculation unit 40. Next, the imaging control unit 50 sends the movement amount to the movement control unit 80. The movement control unit 80 moves the photographing unit 10 to the photographing position by the driving unit 90 based on the instruction from the photographing control unit 50 (S15).
0). When the movement ends, the movement control unit 80 sends a movement end signal to the imaging control unit 50 as necessary. Next, the measurement unit 100 measures the position of the platform (the imaging unit 10) (S160). The photographing control unit 50 compares the received position data (measured value) of the platform (photographing unit 10) with the photographing position data (computed value) calculated by the photographing position calculating unit 40 (S170). The photographing control unit 50 displays the position data and the photographing position data,
Further, if they match or substantially match, a message to that effect may be displayed. If they match or nearly match,
It is determined that the photographing signal is appropriate (OK), and step S180
Proceed to. If not, the process proceeds to step S145. If the photographing position is OK in step S140 or S170, the shutter is operated and photographing is performed by the photographing unit 10 (S180). At this time, if the image data storage unit 30 has a system configuration, the captured image data and the position data (measured value) are simultaneously written into the image data storage unit 30. Next, if the number of shots satisfies the condition, the shooting ends, and if the next shooting is necessary, the process proceeds to step S145 (S190). When the photographing is completed, the signal processing unit 20
Zero means three-dimensional measurement. As described above, it is possible to automatically capture a stereo image.

Here, in the flowchart of the semi-automatic measurement in FIG. 8, the detailed flowchart of the position measurement of the photographing unit 10 in steps S110 and S160 is the same as that in FIG.

Here, the basic principle of three-dimensional measurement by the stereo method will be described. FIG. 10 shows an explanatory diagram of the stereo method. Here, for the sake of simplicity, two identical CCD cameras are used.
Use one. The respective optical axes are parallel and the distance a from the principal point of the camera lens to the CCD surface is equal. Further, it is assumed that the CCD is placed at right angles to the optical axis.
The principle of the stereo method will be described below using these conditions.

Let L be the distance between the two optical axes (base line length).
Point P on object₁(X₁, Y₁), P ₂(X₂, Y₂)of
The following relationship exists between the coordinates. x₁= Ax / z (1) y₁= Y₂= Ay / z (2) x₂-X₁= A × L / z (3) where the origin of the entire coordinate system (x, y, z) is
It shall be taken as the lens principal point. Find z from equation (3)
You. From these results, x and y are obtained from equations (1) and (2).
Can be

When performing stereo shooting, the shooting must be such that a stereo model can be formed from the two acquired images (overlap image). In order to further improve the measurement accuracy, it is necessary to shoot under appropriate conditions as much as possible. For this purpose, the camera 1 on the photographing unit 10 is controlled in three directions of x, y, and z, and can be moved up and down, and the photographing posture position correcting unit 6 having a variable lens magnification is used as the camera of the photographing unit 10. 1 can be provided.

FIG. 11 shows a configuration diagram of a photographing section having a photographing posture position correcting section. This configuration includes a camera 1 and a photographing posture position correcting unit 6. The photographing posture position correction unit 6 measures the posture and orientation of the camera 1 by using a sensor (such as a gyro) and corrects the posture and orientation. As a result, highly reliable measurement can be performed with the data of the photographing data position maintained so that the stereo measurement can be easily performed on the measurement target. Further, the photographing posture position correcting unit 6 includes 3
There are a sensor unit for measuring the axial direction (azimuth and inclination angle), a movable unit that is variable in three axes and a vertical direction, and the magnification of the camera lens can be controlled.

The measurement in three axial directions is performed by using various attitude sensors such as an inclinometer and a direction meter. Alternatively, the three-axis direction may be corrected by placing the camera 1 of the photographing unit 10 on a leveling table. Up and down direction and magnification correction, by using the measurement value of the measurement unit 100,
Correction can be performed with higher accuracy.

These will be described below. FIG. 12 is a diagram illustrating the correction in the vertical direction. As shown in FIG. 12A, when there is a difference in elevation between two photographing positions, the upper and lower ranges to be photographed are different, resulting in an image that is not suitable for measurement. When the position of the imaging unit 10 is measured by the measurement unit 100, a difference in elevation is recognized. Photographing posture position correction unit 6
Moves the camera 1 of the photographing unit 10 up and down to an appropriate height as shown in FIG. 12B based on the three-dimensional data.

FIG. 13 is a diagram for explaining the correction in the horizontal (left / right) direction. As shown in FIG. 13A, the overlapped portion decreases as the object moves in the horizontal direction. It suffices if the photographing unit 10 can be properly controlled at a predetermined position. However, if the photographing unit 10 cannot be brought to an appropriate position for some reason, the camera 1 is directed to the direction of the predetermined measurement range and photographing is performed (FIG. 13B). Since the direction can be known by the gyro of the photographing position correcting unit 6, an appropriate direction is calculated based on the gyro and the photographing position measured by the measuring unit 100, and the camera 1 of the photographing unit 10 is directed in that direction.

FIG. 14 is a diagram for explaining the correction of the swing direction (inclination). If the traveling direction is inclined up and down or left and right, the photographed images are shown in FIGS.
become that way. The vertical direction is, for example, a case where the imaging unit 10 is in a state as illustrated in FIG. In order to avoid these, the vertical position of the photographing posture position correction unit 6-
The inclination of the camera 1 is measured by the left and right inclinometer,
Correct and shoot.

FIG. 15 is a diagram for explaining the magnification correction. As shown in FIG. 15A, a problem occurs when the magnification is different between the two images. For example, when the second image has to be photographed at the positions of the photographing unit 10 and the photographing unit 10 'in FIG.
May not be taken at the position of, and may come to the position of the photographing unit 10 ″. In this case, the measuring unit 100 uses the photographing unit 10
Since the distance to the object to be measured is known, the photographing posture position correction unit 6 adjusts the magnification of the lens of the camera 1. Thus, the difference in magnification between the two images is corrected, and the image is captured with the measurement range being set appropriately.

As described above, by providing the photographing posture correcting unit 6 in the camera 1 of the photographing unit 10 and using the measured values of the various posture sensors and the measuring unit, it is possible to set the photographing conditions suitable for stereo photographing. .

[0032]

According to the present invention, as described above, when performing three-dimensional measurement with an ordinary camera, a stable, highly reliable, and accurate stereo image can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of manual measurement.

FIG. 2 is a configuration diagram of a photographing unit.

FIG. 3 is a configuration diagram of a driving unit.

FIG. 4 is an explanatory diagram of a state of measurement.

FIG. 5 is a flowchart of basic measurement.

FIG. 6 is a flowchart of position measurement.

FIG. 7 is an overall configuration diagram of a second embodiment of the manual measurement.

FIG. 8 is a flowchart of semi-automatic measurement.

FIG. 9 is an explanatory diagram of a photographing position.

FIG. 10 is an explanatory diagram of a stereo method.

FIG. 11 is a configuration diagram of a camera of a photographing unit.

FIG. 12 is an explanatory diagram of vertical correction.

FIG. 13 is an explanatory diagram of left-right direction correction.

FIG. 14 is an explanatory diagram of a swing direction (tilt) correction.

FIG. 15 is an explanatory diagram of magnification correction.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 imaging unit 20 signal forming unit 30 image data storage unit 40 imaging position calculation unit 50 imaging control unit 70 condition setting unit 80 movement control unit 90 driving unit 100 measuring unit 200 signal processing unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Mitsuharu Yamada 75-1 Hasunumacho, Itabashi-ku, Tokyo F-term in Topcon Co., Ltd. (reference) 2F112 AC06 BA06 CA02 CA08 CA12 FA21 FA31 FA35 FA38 5C061 AA20 AB04 AB08

Claims (10)

[Claims] 1. A movable photographing unit on which a photographing camera and a reflecting member are mounted, and a signal forming unit which forms a timing signal indicating a photographing timing when photographed by the camera of the photographing unit. , Is placed at a position distant from the imaging unit, emits measurement light toward a reflecting member of the imaging unit in response to a timing signal from the signal forming unit, and based on reflected light reflected from the reflecting member. A stereo image capturing system comprising: a measuring unit configured to measure a position of the capturing unit. 2. The stereo image photographing system according to claim 1, wherein the camera of the photographing section performs stereo photographing in at least two places, and the measuring section measures the positions of the photographed at least two places. A stereo image capturing system. 3. The stereo image photographing system according to claim 1, wherein the measuring section is further configured to send position data of the measured photographing position to the photographing section. Stereo imaging system. 4. The stereo image photographing system according to claim 1, wherein the position data measured by said measuring section and the photographed image data photographed by a camera of said photographing section are stored in association with each other. Image photographing system further provided with an image storage unit for the. 5. The stereo image photographing system according to claim 1, wherein a three-dimensional object to be photographed is obtained from position data measured by said measuring unit and photographed image data photographed by a camera of said photographing unit. A stereo image capturing system further comprising a signal processing unit for obtaining coordinates. 6. The stereoscopic image capturing system according to claim 1, further comprising: a driving unit for moving the photographing unit; and a movement control unit for controlling the driving unit. Imaging system. 7. An image capturing system according to claim 1, wherein the position data of the image capturing section measured by the measuring section and the image capturing condition data related to the image capturing target are calculated. A stereo image photographing system further comprising: a photographing control unit that performs control for moving the photographing unit based on the position data. 8. The image photographing system according to claim 1, wherein the position data measured by said measuring unit and the image photographed by said photographing unit are taken in response to a timing signal from said signal forming unit. Stereo image capturing system further comprising a capturing control unit for storing the captured image data. 9. The image photographing system according to claim 1, wherein position data indicating a position of said photographing unit measured by said measuring unit, and photographing position data calculated by said photographing position calculating unit. The stereo image photographing system further includes a photographing control unit for displaying that the image data matches or substantially coincides with the image data. 10. The image photographing system according to claim 1, wherein at least the photographing unit is mounted on a platform for photographing, and data is transmitted between the platform and the measuring unit. Stereo imaging system further comprising a transceiver for the camera.