JP2013044827A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve an imaging apparatus capable of zoom-adjusting a subject in stereo-photographing and highly accurately obtaining the three-dimensional position information of the subject from a photographed stereo image.SOLUTION: The imaging apparatus includes first imaging means imaging the subject from a first direction and second imaging means imaging the subject from a second direction different from the first direction, and obtains the three-dimensional position information of the subject by using a first image imaged by the first imaging means and a second image imaged by the second imaging means. The imaging apparatus includes a zoom optical system zoom-adjusting the first image and the second image, to form an image and the zoom optical system includes focal distance detection means detecting a focal distance.

Description

  The present invention relates to an imaging apparatus capable of performing stereo photography by adjusting a zoom of a subject and acquiring highly accurate three-dimensional position information of the subject from the taken stereo image.

  As a conventional stereoscopic imaging device, a stereoscopic camera device (Patent Document 1) that generates a stereo image of a remote subject using a zoom lens, or two types of imaging lenses with fixed focal lengths are switched to three-dimensional the subject. A stereo camera device (Patent Document 2) that acquires position information has been proposed.

  FIG. 4 is a configuration diagram of the stereoscopic camera device of Patent Document 1. The stereoscopic camera device disclosed in Patent Document 1 includes an optical system 331 and 333 that captures polarized light on at least one of a set of optical paths for viewing an observation target, and a set in which at least one is polarized by the optical systems 331 and 333. An optical path synthesizing unit 332 for synthesizing the optical path related to the optical signal with the same optical axis, a lens system 309 for performing focus adjustment and zoom adjustment of output light from the optical path synthesizing unit 332, and an optical signal from the lens system 309 An optical path separation unit 334 that separates the optical path into two optical paths according to the two types of polarization, a set of imaging units 311 and 313 that capture images according to the separated optical signals, and the imaging And image signal processing means 335 provided on the output side of the means 311 and 313.

  According to the stereoscopic camera device of Patent Document 1, since the two left and right images are combined on one optical axis and the zoom operation is performed by one lens system 309, no deviation occurs between the two images, and the stereoscopic effect is eliminated. Is obtained. Further, it is possible to realize a simple and low-cost stereoscopic camera device as compared with the case where two sets of TV cameras are provided as in the prior art.

  FIG. 5 is a configuration diagram of the stereo camera device disclosed in Patent Document 2. The stereo camera device 201 of Patent Document 2 calculates the distance to the subject in a wide range from a short distance to a long distance by the principle of triangulation, and acquires the three-dimensional position information of the subject. As shown in FIG. 5, the first imaging unit 202 and the second imaging unit 203 that are arranged at a predetermined distance apart from each other include long-distance imaging lenses 221 and 231, a short-distance imaging lens 222, 234 is arranged.

  According to the stereo camera device 201 of Patent Literature 2, by acquiring images from the four imaging lenses 221, 222, 231, and 232 having fixed focal lengths, it is possible to acquire three-dimensional position information of a subject in a wide range. It is possible.

JP-A-3-163993 (published July 15, 1991) JP 2010-261877 A (published November 18, 2008)

  When measuring the distance to the subject using the principle of triangulation, there are the following problems.

  FIG. 6 is a schematic diagram illustrating the principle of triangulation. The principle of triangulation is to measure the distance D to the subject, the focal length value f of the imaging device, the baseline length A of the two imaging units for stereo shooting, and the parallax amount n = (nl + nr) in the stereo shooting image. And obtained from the equation D = f × A / n. For example, the base line length A of the imaging unit can be fixed in the imaging apparatus, and the distance D to the subject can be accurately determined by accurately measuring the focal length value f of the imaging apparatus and the parallax amount n of the stereo image. Can be acquired.

  FIGS. 7A and 7B are schematic diagrams showing left and right images IMG1 and IMG2 taken in stereo. FIG. 7A shows an image taken on the wide-angle side, and FIG. 7B shows an image taken on the telephoto side. For example, when shooting two subjects, a flower and a person in the distance, on the wide angle side, as shown in FIG. 7A, the parallax amounts n1 and n2 of each subject are small, so the ranging accuracy is not good. On the telephoto side, the subject is greatly enlarged as shown in FIG. 7B, and the parallax amounts n1 and n2 are also increased, so that the ranging accuracy is improved, and the context information is also acquired from the difference between the parallax amounts n1 and n2. be able to.

  However, since the focal length value f of the lens system 309 fluctuates with zoom adjustment, the stereoscopic camera device of Patent Document 1 is triangulated unless information on the focal length value f with respect to the zoom magnification is acquired in advance. In this case, it is difficult to acquire the information of the focal length value f in detail, so that there is a problem that the accuracy of the triangulation is lowered.

  In Patent Document 2, the magnification of the first imaging unit 202 and the second imaging unit 203 is fixed to two types, that is, the wide-angle side and the telephoto side, and depending on the shooting conditions such as the size and distance of the subject, Cannot be taken with a moderate magnification. For this reason, the captured image is too small on the wide-angle side and the resolution is lowered, and the telephoto side is too large and deviates from the imaging region, so that the amount of parallax cannot be accurately measured, and the three-dimensional position information is high. There was a problem that it could not be acquired with accuracy.

  The present invention has been made in view of such a problem, and an object of the present invention is to perform stereo shooting by adjusting a subject to zoom, detect a focal length value f and a parallax amount at the time of zoom shooting, and detect 3 of the subject. An object of the present invention is to realize an imaging apparatus capable of acquiring dimension position information with high accuracy.

  A first imaging unit that images the subject from a first direction; and a second imaging unit that images the subject from a second direction different from the first direction. An imaging apparatus that acquires three-dimensional position information of a subject using a first image and a second image captured by a second imaging unit, the imaging apparatus including the first image and the second image The zoom optical system includes a zoom optical system that forms an image by performing zoom adjustment, and the zoom optical system includes a focal length detection unit that detects a focal length.

  According to the present invention, the subject can be zoomed to ensure a sufficient amount of parallax for measurement, the focal length value at the time of zoom shooting can be detected, and the three-dimensional position information of the subject can be obtained with high accuracy.

1 is a configuration diagram of an imaging apparatus according to Embodiment 1. FIG. It is the graph and schematic diagram explaining the structure of the detection part of a focal distance. FIG. 6 is a configuration diagram of an imaging apparatus according to a second embodiment. It is a block diagram of the stereo camera apparatus of patent document 1 which is a prior art. It is a block diagram of the stereoscopic camera apparatus of patent document 2 which is a prior art. It is a schematic diagram explaining the principle of triangulation. It is a schematic diagram which shows the image data image | photographed by the stereo at the wide angle side and the telephoto side.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts.

  FIG. 1 is a configuration diagram of an imaging apparatus 50 according to the present invention. The imaging apparatus 50 includes a first imaging unit that images a subject from a first direction, and a second imaging unit that images the subject from a second direction different from the first direction. Using the first image captured by the means and the second image captured by the second imaging means, the three-dimensional position information of the subject is acquired.

  The first imaging unit includes a light incident unit 1a that captures the image A1 of the subject O, a zoom optical system 2a that performs zoom adjustment of the image A1, and an imaging sensor 6a that captures the zoom-adjusted image A1. Similarly to the configuration of the first imaging unit, the second imaging unit also includes a light incident unit 1b that captures an image A2 of the subject O, a zoom optical system 2b, and an imaging sensor 6b.

  Also, an image processing unit 7 that calculates the three-dimensional position information of the subject using a stereo image composed of the images A1 and A2 captured by the imaging sensors 6a and 6b, an input unit 8 for operating the imaging device 50, A display unit 9 that displays a stereo image and three-dimensional position information of the subject, and a control unit 10 that controls each unit of the imaging device 50 are provided.

  The image pickup apparatus 50 of the present invention is characterized in that, in the above configuration, the focal length detection means 5a and 5b for detecting the focal length when the zoom optical systems 2a and 2b are adjusted for zooming are provided. The imaging device 50 of the present invention secures a sufficient amount of parallax for measuring the three-dimensional position information by adjusting the magnifications of the images A1 and A2 from different directions of the subject O by the zoom optical systems 2a and 2b. At the same time, by detecting the focal length value during zoom adjustment of the zoom optical systems 2a and 2b, the distance to the subject can be measured with high accuracy using the principle of triangulation.

  Each configuration of the imaging device 50 of the present invention will be described with reference to FIG. The light incident portions 1a and 1b are optical members such as lenses, which are arranged on the front surface of the imaging apparatus 100 at a predetermined interval, and capture the subject O as images A1 and A2 from different directions. The interval between the light incident portions 1a and 1b is set to about 20 mm, for example, and is used as the base line length A in the triangulation measurement.

  The zoom optical systems 2a and 2b are configured by a lens group including zoom lenses 3a and 3b and focus lenses 4a and 4b, so that the images A1 and A2 captured by the light incident portions 1a and 1b are zoomed at the same magnification. In addition, the two zoom optical systems 2a and 2b are driven in conjunction with each other.

  The zoom optical systems 2a and 2b are provided with focal length detection means 5a and 5b in order to detect a focal length value f that fluctuates due to zoom adjustment. The configuration and operation of the focal length detection means 5a and 5b will be described later.

  The image sensors 6a and 6b are image sensors such as a CCD image sensor and a CMOS image sensor. The images A1 and A2 zoom-adjusted by the zoom optical systems 2a and 2b are A / D converted, and each of them is used as image data. Output to the processing unit 7.

  The image processing unit 7 includes a CPU, a memory, and the like. The image processing unit 7 corrects the image data A1 and A2, generates a stereo image, measures the three-dimensional position information of the subject from the stereo image, and outputs these processing results. It outputs to the display means 9. Note that the image data, the three-dimensional position information of the subject, and the like can be stored in a storage unit such as a memory card or a hard disk.

  The input unit 8 includes buttons, dials, and the like for operating the imaging device 50, and performs shooting operations such as various settings of the imaging device 50 and zoom adjustment.

  The display unit 9 includes a display device such as a liquid crystal panel, and displays a stereo image of the subject or three-dimensional position information of the subject. The display means 9 can also be used as the input means 8 in combination with a touch panel.

  The control unit 10 controls the zoom optical systems 2 a and 2 b, the image processing unit 7, and the display unit 9 in accordance with the operation instruction input to the input unit 8. For example, when the user operates the zoom button of the input unit 8, the control unit 10 interlocks the zoom lenses 3a and 3b, the focus lenses 4a and 4b, and the zoom optical systems 2a and 2b are zoom-adjusted at the same magnification. To drive.

  Next, the focal length detection means 5a and 5b, which are features in the image pickup apparatus 50 of the present invention, will be described.

  FIG. 2A is a schematic diagram showing a configuration of the focal length detection means 5a, 5b, and FIG. 2B is a graph showing a focal length value calculation method by the focal length detection means 5a, 5b.

  As shown in FIG. 2A, the zoom lenses 3a and 3b are step-driven by the stepping motor 22 along the drive shaft 21 provided between the WIDE end and the TELE end of the zoom optical systems 2a and 2b. .

  The focal length detection means 5a and 5b include a position sensor 23 provided as a reference position at the WIDE end, a light shielding unit 24 provided in the zoom lenses 3a and 3b, and a CPU 25 that counts the number of steps of the stepping motor 22. .

  The position sensor 23 has, for example, a light emitting unit and a light receiving unit that face each other, and the light receiving unit detects the presence or position of the object by detecting that the object blocks the light from the light emitting unit. It is. Then, when the light receiving unit is blocked by the light blocking unit 24 of the zoom lenses 3a and 3b, it is detected that the zoom lenses 3a and 3b are at the reference position.

  In the focal length detection means 5a and 5b, when the zoom lenses 3a and 3b are at the reference position, the CPU 25 resets the step number p of the stepping motor 21 to 0, and the zoom lenses 3a and 3b move from the reference position to the zoom position. The zoom position is calculated as a relative position from the reference position by counting the number of steps p required for the above.

  As shown in FIG. 2B, it is known in advance that the focal length value f of the zoom optical systems 2a and 2b is proportional to the position of the zoom lenses 3a and 3b. Since the zoom position can be calculated from the step number p of the stepping motor 21, the focal length value f can be obtained as a function g (p) of the step number p. Note that the function g (p) varies depending on the configuration of the lens group.

  The imaging device 50 of the present invention includes zoom optical systems 2a and 2b that enable zoom adjustment of the subject, and as shown in FIG. 7B, the subject images A1 and A2 are placed on the telephoto side. The parallax amount n sufficient for the measurement of the three-dimensional position information can be detected by performing zoom adjustment and performing large imaging within a range that falls within the imaging area of the imaging sensors 6a and 6b.

  Further, it includes focal length detection means 5a and 5b for calculating the focal length value f of the zoom optical systems 2a and 2b, detects an accurate focal length value f at the time of zoom adjustment, and detects the detected parallax amount n and the focal length. Using the value f, the distance D to the subject can be measured with high accuracy from the formula D = f × A / n by the principle of triangulation.

  In the imaging apparatus 50 of the first embodiment, the focal length detection units 5a and 5b have been described with the reference position of the zoom optical systems 2a and 2b set to the WIDE end, but the reference position may be set to the TELE end. Further, although the focal length value f is obtained from the position where the zoom lenses 3a and 3b are moved, the focal length value f may be obtained by detecting the positions of the focus lenses 4a and 4b. Further, since the zoom optical systems 2a and 2b are driven so as to have the same magnification in conjunction with each other, the focal length value f may be obtained from one of the focal length detection means 5a and 5b.

  FIG. 3 is a configuration diagram of the imaging device 60 according to the second embodiment of the present invention. The imaging apparatus 60 according to the second embodiment has a configuration in which the first image A1 and the second image A2 are zoom-adjusted using the single zoom optical system 2c with respect to the imaging apparatus 50 illustrated in the first embodiment. Different. Since other configurations are the same as those of the imaging device 50 of the first embodiment, detailed description thereof is omitted.

  The imaging device 60 according to the second embodiment has two light incident portions 1a and 1b that capture the subject O from different directions as images A1 and A2, respectively, and the captured images A1 and A2 that have different polarizations and have the same optical axis. Using the difference in polarization between the polarized light combining unit 11 to be combined with the zoom, the zoom optical system 2c for zoom adjusting the image A1 and the image A2 combined with the polarized light combining unit 11, and the image A1 and the image A2 through which the zoom adjustment has been performed. Three-dimensional position information of the subject from the polarization separation unit 12 that separates the light again, the two imaging sensors 6a and 6b that respectively form the separated images A1 and A2, and the stereo images of the imaging sensors 6a and 6b. The zoom optical system 2c is provided with focal length detection means 5c for detecting the focal length during zoom adjustment.

  In addition, an input unit 8 for operating the imaging device 60, a display unit 9 for displaying a stereo image and three-dimensional position information of the subject, and a control unit 10 for controlling each unit of the imaging device 60 are provided.

  The image pickup apparatus 60 according to the second embodiment has a three-dimensional structure while preventing the displacement of the magnification between the image A1 and the image A2 by zooming the images A1 and A2 of the subject O with the single zoom optical system 2c. A sufficient amount of parallax for measuring position information can be secured, and an accurate focal length value at the time of zoom adjustment of the zoom optical system 2c is detected, and the distance to the subject is determined with high accuracy using the principle of triangulation. It is possible to measure.

  Each configuration of the imaging device 60 according to the second embodiment will be described with reference to FIG.

  The light incident portions 1a and 1b are optical members such as lenses, which are arranged on the front surface of the imaging apparatus 100 at a predetermined interval, and capture the subject O as images A1 and A2 from different directions. The interval between the light incident portions 1a and 1b is set to about 20 mm, for example, and is used as the base line length A in the triangulation measurement.

  The polarization combining unit 11 includes a polarizing film that transmits S-polarized light or P-polarized light from the images A1 and A2 captured by the light incident units 1a and 1b, and a prism that converts the optical paths of the images A1 and A2. The polarization combiner 11 converts the images A1 and A2 into S-polarized light and P-polarized light so that their polarizations are different from each other, and combines the images A1 and A2 converted into S-polarized light and P-polarized light on the same optical axis, The light is emitted to the zoom optical system unit 2c.

  The zoom optical system 2c is composed of a plurality of lens groups including a zoom lens 3c and a focus lens 4c so as to have the same optical axis as the combined images A1 and A2. The zoom optical system 2c can adjust the images A1 and A2 combined by the polarization combining unit 11 to a desired magnification using the zoom lens 3c and adjust the focus using the focus lens 4c.

  The zoom optical system 2c according to the second embodiment is shared by one system, thereby facilitating the control of the zoom lens 3c and the focus lens 4c, and preventing the magnification difference between the image A1 and the image A2. Further, it is possible to reduce the size of the zoom optical system 2c and reduce the component cost.

  The focal length detection means 5c detects the focal length value f after zoom adjustment of the zoom optical system 2c. The configuration and operation of the focal length detection means 5c are the same as those shown in the first embodiment.

  The polarization separation unit 12 is composed of a polarizing film and a prism. The combined light of the image A1 and the image A2 adjusted to a desired magnification by the zoom optical system 2c is zoom-adjusted 2 using the difference in polarization. The images are separated into two images A1 and A2.

  The image pickup means 6a and 6b are image pickup devices such as a CCD image sensor and a CMOS image sensor, which perform A / D conversion on the zoom-adjusted images A1 and A2, and use the respective images A1 and A2 as image data. Output to the processing unit 7. The configurations and operations of other input means 8, display means 9, and control unit 10 are the same as those shown in the first embodiment.

  The image pickup apparatus 60 according to the second embodiment prevents the displacement of the magnification between the image A1 and the image A2 during zoom adjustment by performing zoom adjustment on the images A1 and A2 of the subject O using the single zoom optical system 2c. However, it is possible to secure a sufficient amount of parallax for measurement of three-dimensional position information, and to detect an accurate focal length value at the time of zoom adjustment of the zoom optical system 2c, and to use the principle of triangulation to determine the distance to the subject. Can be measured with high accuracy.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the scope of the present invention is indicated by the scope of claims, and the meaning and scope equivalent to the scope of claims. All changes within are intended to be included.

O Subject A1, A2 Image 1a, 1b Light incident part 2a, 2b, 2c Zoom optical system 3a, 3b, 3c Zoom lens 4a, 4b, 4c Focus lens 5a, 5b, 5c Focal length detection means 6a, 6b Imaging sensor 7 Image Processing unit 8 Input unit 9 Display unit 10 Control unit 11 Polarization combining unit 12 Polarization separation unit 21 Stepping motor 22 Position sensor 23 Light shielding unit 50, 60 Imaging device

Claims (5)

First imaging means for imaging a subject from a first direction;
Second imaging means for imaging the subject from a second direction different from the first direction;
A first image captured by the first imaging means;
An imaging apparatus that acquires three-dimensional position information of the subject using a second image captured by the second imaging means,
The imaging apparatus includes a zoom optical system that forms an image by performing zoom adjustment on the first image and the second image,
The zoom optical system includes an focal length detection unit that detects a focal length.   The imaging apparatus according to claim 1, wherein the focal length is associated with a zoom position of a lens of the zoom optical system.   The imaging apparatus according to claim 2, wherein the zoom position of the lens is calculated by the number of steps of a stepping motor of the zoom optical system.   The imaging apparatus according to claim 3, wherein the number of steps is a number of steps required to move the lens from a reference position to the zoom position.   The image pickup apparatus according to claim 4, wherein a photo interrupter is provided at the reference position, and a light shielding portion is provided on the lens.