JP2011114363A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus providing images of different light projection states without changing the state of an object to be a photographing object. <P>SOLUTION: The imaging apparatus includes a light projection means 5 for projecting an object X, an imaging means 3 for photographing the object X and acquiring image data, a timing control means 6 for controlling the light projection timing of the light projection means 5 and the photographing timing of the imaging means 3, an image data storage means 7 for storing the acquired image data, and an interface 12 for transferring the image data stored in the image data storage means 7 to a computer 11. The timing control means 6 causes the imaging means 3 to perform continuous photographing, and switches the light projection state by the light projection means 5 in synchronism with continuous photographing. The image data storage means 7 stores continuously photographed image data, and when the continuous photographing is ended, the image data stored in the image data storage means 7 are transferred through the interface 12 to the computer 11. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus for suitably acquiring an image used for measurement and recognition of a three-dimensional object.

  Conventionally, as a method for obtaining the three-dimensional shape of an object, for example, a method of measuring a distance to each point by projecting a laser beam onto a measurement object and measuring the reflected light is used. There are active methods such as a method of measuring a three-dimensional shape of a measurement object by projecting pattern light and measuring the shape of the pattern projected onto the measurement object.

  In addition, the corresponding reference image is specified by identifying corresponding pixels among a plurality of images obtained by photographing the measurement object with two or more cameras of a reference camera and a reference camera provided at different positions. Stereo that measures the distance from the reference camera to the point on the measurement object corresponding to the pixel by applying triangulation limitation to the difference in position (parallax) between the upper pixel and the pixel on the reference image There are things called laws. In these methods, a stereo camera (see, for example, Patent Document 1) is generally used in which two cameras having the same performance are arranged side by side at the same interval as both eyes and the same subject is simultaneously photographed.

JP 2001-091245 A

  However, in a stereo camera, in order to make an object to be measured stand out and be easy to detect, there are cases where acquisition of an image with a different illumination state for projecting the object is required. In stereo cameras, when shooting images with different lighting conditions, it is necessary to switch the lighting state each time and press the shutter, so there is a problem that the state changes as the object moves. May occur.

  The present invention has been made in view of the problems as described above, and provides an imaging apparatus capable of acquiring images with different projection states without changing the state of a subject to be photographed. With the goal.

  In order to achieve the above object, the imaging apparatus according to claim 1, a light projecting unit that projects light onto a subject to be imaged, an image capturing unit that captures image data by capturing the subject, Timing control means for controlling the light projection timing by the light projecting means and the photographing timing by the imaging means, image data storage means for storing image data acquired by the imaging means, and the image data stored in the image data storage means An interface for transferring image data to a computer, and the timing control unit causes the imaging unit to continuously shoot, and switches a light projection state by the light projecting unit in synchronization with continuous shooting by the imaging unit, The image data accumulating unit accumulates image data continuously photographed in different light projection states, and is connected by the image capturing unit. When the picture is taken, the image data stored in said image data storage means is characterized in that is transferred to the computer via the interface.

  The imaging apparatus according to claim 2, wherein the light projecting unit projects a plurality of illumination devices that project illumination light onto the subject, and the timing control unit causes the image capturing unit to continuously shoot, and The illumination state by the illumination device is switched in synchronism with the continuous photographing by the imaging means.

  The imaging apparatus according to claim 3, wherein the light projecting unit is a pattern projector that projects pattern light onto the subject or a strobe that projects flash light onto the subject, and the timing control unit includes the imaging unit. The pattern projector or the strobe is switched between light projection and non-light projection in synchronism with the continuous photographing by the image pickup means.

  The imaging apparatus according to claim 4 uses Gigabit Ethernet (registered trademark) as an interface for transferring the image data stored in the image data storage means to the computer, and supplies the power to the Gigabit Ethernet (registered trademark). The PoE (Power over Ethernet) performed by the communication cable used in (1) is used.

  According to the imaging apparatus of the first aspect, by controlling not only the imaging unit but also the light projecting unit and changing the light projection state to continuously capture images, it is possible to obtain images with different image capture methods, so a difference is taken. In this way, the subject to be measured can be made to stand out, and processing such as contour extraction can be facilitated. In addition, the subject is continuously shot, and the continuously shot images are stored in the image data storage means. After the continuous shooting is completed, the image data is transferred to the computer. Since the time for transferring image data to the computer can be saved, the time between continuous shooting can be shortened. As a result, it is possible to prevent a change in the state due to the influence of the movement of the subject to be imaged and so on, so that an image suitable for measurement and recognition of a three-dimensional object can be acquired.

  According to the imaging device of the second aspect, since the plurality of illumination devices that project the illumination light to the subject are provided, the illumination state of the plurality of illumination devices is switched in synchronization with the continuous shooting by the imaging unit. Images with different illumination states can be suitably acquired.

  According to the imaging apparatus of the third aspect, since the pattern projector is switched between projection and non-projection in synchronization with the continuous shooting by the imaging means, the image of the subject onto which the pattern light is projected and the pattern light are An image of a subject that is not projected can be quickly acquired. Also, by switching between light projection and non-light projection in synchronism with continuous shooting by the imaging means, it is possible to quickly acquire an image of a subject to which a flash is projected and an image of a non-projection subject. Therefore, it is efficient to obtain these difference images.

  According to the imaging device of the fourth aspect, since the Gigabit Ethernet (registered trademark) is used as an interface for transferring image data to the computer, the positional relationship between the imaging device and the computer can be set in various variations. In addition, since PoE can be used to supply power, it is highly convenient.

It is a schematic diagram showing an example of the appearance of the imaging device concerning a 1st embodiment of the present invention. It is a schematic block diagram which shows an example of a structure of the imaging device which concerns on 1st Embodiment. It is explanatory drawing for demonstrating an example of the light projection timing and imaging | photography timing of the imaging device which concerns on 1st Embodiment. It is explanatory drawing for demonstrating the light projection timing and imaging | photography timing of an imaging device. It is a schematic block diagram which shows an example of a structure of the imaging device which concerns on 2nd Embodiment. It is explanatory drawing for demonstrating an example of the light projection timing and imaging | photography timing of the imaging device which concerns on 2nd Embodiment. It is a schematic diagram which shows an example of the external appearance of the imaging device which concerns on 3rd Embodiment. It is a schematic block diagram which shows an example of a structure of the imaging device which concerns on 3rd Embodiment.

  Hereinafter, an imaging device 1 according to a first embodiment of the present invention will be described with reference to the drawings. This imaging device 1 is a so-called stereo camera for acquiring an image suitable for measurement and recognition of a three-dimensional object, and as shown in FIG. 1, the appearance thereof is a housing containing functions necessary for three-dimensional measurement. Two imaging units 3 (3a, 3b) are integrally provided on the body 2 while maintaining a positional relationship necessary for stereo measurement, and the illumination device 5 is provided outside the housing 2 via two signal cables 4. (5a, 5b) are provided.

  As shown in FIG. 2, the imaging device 1 includes an illumination device 5 (5a, 5b) that projects illumination light onto a subject X to be imaged, and an imaging unit 3 that captures the subject X and acquires image data. 3a, 3b), a timing control unit 6 for controlling the imaging timing of the imaging unit 3 and the illumination light projection timing in the illumination device 5, and the image data storage unit 7 for storing the image data acquired by the imaging unit 3. A control unit 8 that controls processing operations according to settings of each unit, an operation unit 9 for performing various settings, a display unit 10 that displays image data acquired by the imaging unit 3, and an external unit An interface 12 for performing data communication or the like with the computer 11 or the like is provided.

  The illumination devices 5a and 5b use, for example, LED illumination as a light source, and are arranged so that illumination light can be projected onto the subject X from different angles. The imaging units 3a and 3b are provided with imaging elements such as CCD and CMOS having the same performance function, and the subject X is simultaneously photographed from the imaging units 3a and 3b to obtain image data.

  The timing control unit 6 controls the photographing timing of the imaging unit 3, the illumination light projection timing of the illumination device 5, and the like. Further, the shooting timing, exposure time by the imaging unit 3, and the light projection timing, light projection time, etc. by the illumination device 5 are set in advance by commands sent from the external computer 11, for example, and according to the settings. The timing control unit controls the imaging unit 3 and the illumination device 5. Therefore, if these settings are made in advance, the processing is automatically performed only after a trigger is given by a shutter command from the computer 11 or the operation unit 9.

  The image data storage unit 7 is for storing the image data of the subject photographed by the imaging unit 3, and a set of four pieces of image data continuously photographed by the imaging units 3a and 3b with their photographing timings synchronized with each other. Is to accumulate. The control unit 8 is a camera control unit such as gain setting, white balance, luminance conversion, and contrast conversion, and transfer that controls transfer of image data stored in the image data storage unit 7 by an operation from the operation unit 9 or the like. It functions as a control means.

  The operation unit 9 includes an operation button, a shutter button, and the like for setting each unit as described above. The display unit 10 includes, for example, a liquid crystal display or the like, and displays an image acquired by the imaging unit 3 or displays setting information of each other unit. The interface 12 is used for communication with an external computer 11, and the image data stored in the image data storage unit 7 is transferred to the computer 11 via the interface 12. As this interface 12, for example, a GigE (Gigabit Ethernet) interface is used, and PoE (Power over Ethernet) is used to supply power to the imaging apparatus 1 with a communication cable used in the Gigabit Ethernet (registered trademark). To do. The interface 12 is not limited to this, and a known interface such as a wired interface such as RS-232C or USB, or a wireless interface that transmits and receives an infrared signal can also be applied. The computer 11 stores in advance a program for performing three-dimensional measurement, three-dimensional recognition, and the like, and these processes are performed by using the image data stored in the image data storage unit 7.

  Next, the processing operation of the imaging apparatus 1 will be described. In the imaging device 1, the shooting timing and exposure time by the imaging unit 3 and the light projection timing and light projection time by the illumination device 5 are set in advance by a command from the computer 11, and based on this setting, the timing control unit 7 The continuous shooting of the imaging unit 3 and the light projection of the illumination device 5 are controlled. FIG. 3 shows an example of the processing of the imaging apparatus 1. Photographing A shows the first half of the photographing timing in continuous photographing, and the length in the horizontal direction is for photographing including the exposure time of the photographing 3a and 3b. It represents the time interval required. Similarly, shooting B shows the shooting timing in the latter half of the continuous shooting.

  As shown in FIG. 3, the imaging apparatus 1 automatically performs a series of processing operations when a trigger is given by a shutter command from the computer 11 or the operation unit 9. In FIG. 3, the illumination control signal S <b> 1 is In the first half of shooting A, a low level is output to project illumination light, and the illumination control signal S2 shows an example of outputting the low level to project illumination light in the second half of shooting B. ing. Specifically, the shooting timing and operation timing of the imaging units 3a and 3b are completely synchronized, and the illumination control signal S1 is at a low level so as to synchronize with the first shooting A of the continuous shooting of the imaging units 3a and 3b. During shooting A, the subject X is projected by the lighting device 5a, and the shooting A is terminated and the projection by the lighting device 5a is terminated. Then, the illumination control signal S2 outputs a low level so as to synchronize with the second half of the continuous shooting of the continuous shooting of the imaging units 3a and 3b. At the same time, the lighting device 5b switches so as to end the light projection. That is, the timing control unit 6 controls to output the illumination control signals S1 and S2 so as to switch the states of the illumination devices 5a and 5b at the timing of each set of image capturing.

  In this way, a set of four pieces of image data continuously shot under different illumination conditions is stored in the image data storage means 7. Then, after the continuous shooting is completed, these image data are transferred to the computer 11 via the interface 12. Therefore, the image data is not transferred to the computer 11 for each shooting, but a set of four image data is temporarily stored in the image data storage device 7 and transferred to the computer 11 after the continuous shooting is completed. The time interval between continuous shooting can be shortened. As a result, the possibility that the state changes due to the influence of the movement of the subject X and the like can be reduced, so that an image suitable for measurement and recognition of a three-dimensional object can be acquired. In addition, by continuously capturing images with different illumination states, image data with different ways of capturing can be acquired, so that an object to be measured can be made to stand out and easily detected, and thus contour extraction and the like are facilitated.

  3 shows an example in which illumination light is projected from the illumination devices 5a and 5b when the signal levels of the illumination control signals S1 and S2 are low, respectively, the signals of the illumination control signals S1 and S2 are shown. You may comprise so that illumination light may be projected from illuminating device 5a, 5b, respectively, when a level is a high level. Further, in the present embodiment, an example in which two illumination devices 5a and 5b are arranged is shown. However, in the present invention, it is only necessary to continuously shoot images with different illumination states of the illumination light on the subject X. A set of four pieces of image data may be acquired by performing continuous shooting using an illumination device. For example, when three illumination devices 5 are used, the subject X in which illumination light is projected from the two illumination devices 5 is photographed in the first shooting A, and the remaining one illumination device 5 is photographed in the second shooting B. It is of course possible to adopt a configuration in which the illumination state is switched by the illumination control signals S1 and S2 so that the subject X projected with the illumination light is photographed.

Further, in the present embodiment, an example in which one illumination device 3a is projected by the illumination control signal S1 at the time of shooting A, and another illumination device 3b is projected by the illumination control signal S2 at the time of shooting B. However, the example of the light projection timing is not limited to this, and as shown in FIG. 4, the ON / OFF switching of the light projection by the illumination control signal S1 and the illumination control signal S2 and the light projection timing thereof Depending on the change, 16 (2 ⁴ ) patterns can be considered.

  Next, an imaging apparatus 1a according to the second embodiment will be described with reference to FIGS. The imaging device 1a according to the second embodiment is provided with a strobe 13 instead of the illumination devices 3a and 3b of the imaging device 1, and the other components similar to those of the imaging device 1 according to the first embodiment. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  The strobe 13 is a photographic artificial light source using an electronic flash mounted on a general camera. In the imaging device 1a, the image data when the flash by the strobe 13 is projected and the image data when the flash is not projected are acquired by the imaging means 3a and 3b. In the imaging apparatus 1a, the shooting timing by the imaging unit 3, the exposure time, and the projection timing and projection time by the strobe 13 are set in advance by a command from the computer 11, and the timing control unit 6 performs imaging based on these settings. The continuous shooting by the unit 3 and the light projection by the strobe 13 are controlled.

  FIG. 6 shows an example of processing of the image pickup apparatus 1a. Like FIG. 3, the shooting A shows the first half shooting timing in the continuous shooting, and the horizontal length is the exposure of the shooting 3a and 3b. The time interval required for shooting including time is shown, and shooting B indicates the shooting timing in the latter half of the continuous shooting. As shown in FIG. 6, when a trigger is given by a shutter command from the computer 11 or the operation unit 9, the imaging device 1 a has an illumination control signal S <b> 1 so as to synchronize with the first shooting A of the continuous shooting of the imaging units 3 a and 3 b. Outputs a low level and projects the subject X with the flash 13 during shooting A, and switches to finish shooting A and end the projection with the flash 13. Then, in shooting B in the latter half of the continuous shooting by the imaging units 3a and 3b, the subject X is shot by the imaging units 3a and 3b in a state where the flash by the strobe 13 is not projected. As a result, a set of four pieces of image data in a state where the flash by the strobe 13 is projected and image data in a state where the flash by the strobe 13 is not projected can be acquired. The set of four pieces of image data is stored in the image data storage unit 7 and is transferred to the computer 11 via the interface 12 after the continuous shooting is completed.

  FIG. 6 shows an example in which the strobe 13 projects the subject X in synchronization with the shooting A in the first half of the continuous shooting by the imaging units 3a and 3b by the illumination control signal S1. Of course, it is also possible to configure the strobe 13 not to emit light during the first half of shooting A, but to project the flash 13 during shooting B in the second half of the continuous shooting by the imaging units 3a and 3b.

  The imaging apparatus 1b according to the third embodiment replaces the strobe of the imaging apparatus 1a with a pattern projector 14 that projects pattern light onto the subject X between the imaging units 3a and 3b as shown in FIGS. Are integrated. The pattern projector 14 applies a special pattern having a projector function to the subject X as illumination. For example, a non-periodic random pattern is projected as pattern light.

  Also in the imaging apparatus 1b, the shooting timing and exposure time by the imaging unit 3 and the projection timing and projection time by the pattern projector 14 are set in advance by a command from the computer 11, and the timing is set based on this setting. The control unit 6 controls continuous shooting by the imaging unit 3 and light projection by the pattern projector 14.

  Similar to the imaging device 1a, the imaging device 1b is synchronized with the first shooting A of the continuous shooting of the imaging units 3a and 3b when a trigger is given from the computer 11 or the operation unit 9 as shown in FIG. As described above, the illumination control signal S1 outputs a low level so that the subject X is projected by the pattern projector 14 during the photographing A, and the photographing by the pattern projector 14 is finished while the photographing A is finished. Switch. Then, in shooting B in the latter half of the continuous shooting of the imaging units 3a and 3b, the subject X is shot by the imaging units 3a and 3b in a state where pattern light from the pattern projector 14 is not projected. Thereby, it is possible to acquire a set of four pieces of image data in a state where the pattern light is projected and image data in a state where the pattern light is not projected. Similarly, in the image pickup apparatus 1b, the acquired set of four pieces of image data is stored in the image data storage unit 7, and after continuous shooting is completed, the image data is transferred to the computer 11 via the interface 12. . Also in the present embodiment, the pattern light is not projected during the first half of the continuous shooting, but the pattern light is projected during the second half of the continuous shooting B by the imaging units 3a and 3b. Of course, it is also possible to make such a configuration. Further, a projector for projecting a line laser or the like may be provided instead of the pattern light.

  Note that the embodiment of the present invention is not limited to the above-described embodiment, and it is needless to say that the embodiment can be appropriately changed without departing from the scope of the idea of the present invention.

  The imaging apparatus according to the present invention can be effectively used as an imaging apparatus for suitably acquiring an image used for measuring or recognizing a three-dimensional object.

1, 1a, 1b Imaging device 3, 3a, 3b Imaging unit 5, 5a, 5b Illumination device (light projection means)
6 Timing control unit 7 Image data storage unit 11 Computer 12 Interface 13 Strobe (light projection means)
14 Pattern projector (light projection means)

Claims (4)

A light projecting means for projecting light onto a subject to be imaged;
Imaging means for capturing the subject and acquiring image data;
Timing control means for controlling the light projection timing by the light projection means and the photographing timing by the imaging means;
Image data storage means for storing image data acquired by the imaging means;
An interface for transferring the image data stored in the image data storage means to a computer,
The timing control unit causes the imaging unit to continuously shoot and switches the light projection state by the light projecting unit in synchronization with the continuous shooting by the imaging unit, and the image data storage unit continuously shoots in different light projection states. The image data stored is stored, and when the continuous shooting by the imaging unit is completed, the image data stored in the image data storage unit is transferred to the computer via the interface. An imaging device. The light projecting means is a plurality of illumination devices that project illumination light onto the subject,
2. The imaging apparatus according to claim 1, wherein the timing control unit causes the imaging unit to continuously shoot and switches the illumination state of the plurality of lighting devices in synchronization with continuous shooting by the imaging unit. The light projecting means is a pattern projector that projects pattern light onto the subject or a strobe that projects flash onto the subject,
The timing control unit causes the imaging unit to continuously shoot, and performs switching between projection and non-projection of the pattern projector or the strobe in synchronization with continuous shooting by the imaging unit. Item 2. The imaging device according to Item 1.   As an interface for transferring the image data stored in the image data storage means to the computer, a Gigabit Ethernet (registered trademark) is used, and as a power supply, PoE is performed using a communication cable used in the Gigabit Ethernet (registered trademark). The imaging apparatus according to claim 1, wherein (Power over Ethernet) is used.

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