JP2006251683A - Stereoscopic image photographing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stereoscopic image photographing system capable of accurately matching the sizes of the images of the same subject in right and left parallax images, i.e. the magnifications of the right and left parallax images, without requiring the time and labor in generating correct data by correcting the right and left parallax images forming stereoscopic images by an electron zoom. <P>SOLUTION: Right and left video signals outputted from right and left video cameras 10A, 10B are inputted to an image processor 20. The video signal on the right side is subjected to electron zoom processing by an electronic zoom circuit 72 in the image processor 20. The electronic zoom magnification in the electronic zoom circuit 72 is set on the basis of the images of the right and left video signals in an image processing section 70. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stereoscopic image capturing system, and more particularly to a stereoscopic image capturing system that captures a stereoscopic image by capturing parallax images for the right eye and the left eye using two cameras.

  For example, a stereoscopic camera that shoots a stereoscopic image (stereoscopic image) for binocular stereoscopic viewing by arranging two right and left television cameras in parallel and capturing parallax images for the right eye (right side) and left eye (left side). It has been known.

  In a stereoscopic camera, in order to capture a stereoscopic image without a sense of incongruity, photographing lenses of the same type (same performance) are used as the optical systems of the left and right cameras. In addition, since the shooting conditions such as zoom (focal length) and focus (focal position) must always be matched on the left and right for the control of the shooting lens, for example, shooting of the main shooting lens with one as the main and the other as the slave. When the condition is changed, the photographing condition of the slave photographing lens is changed accordingly.

  By the way, even if the photographing lenses are of the same type, there are individual differences due to manufacturing errors, and there are also individual differences in sensors used for control, for example, position sensors that detect the zoom position. Therefore, even if the left and right cameras use the same type of photographic lens and the left and right photographic lenses are controlled to have the same photographic condition based on the signal value from the sensor, it is difficult to completely match the photographic conditions. In particular, when using a photographic lens with a zoom function (zoom lens), if there is a difference in the focal length of the left and right photographic lenses, the photographic magnifications of the left and right cameras do not match, and the right and left parallaxes The size of the subject in the image (the size of the image of the same subject) is different. If the size of the subject in the left and right parallax images is different, the image becomes very difficult for the viewer to see, and there is a problem that fatigue increases when viewing for a long time.

  In order to solve such a problem, for example, in Patent Document 1, the output of the position sensor that detects the zoom position of the left and right photographing lenses (zoom lenses) is corrected by a look-up table to correct the zoom position by the position sensor. It has been proposed to make the detection characteristics coincide with each other.

In Patent Document 2, in the control of the zoom lens group (variable lens group) in the left and right photographing lenses (zoom lens), the right and left photographing is corrected by correcting the relative positional relationship of the left and right variable magnification lenses. It has been proposed to match the zoom ratio (focal length) of the lenses.
Japanese Patent No. 3303255 Japanese Patent No. 3117303

  However, in the methods of Patent Document 1 and Patent Document 2, it is determined how much the output distance of the sensor and the position of the zoom lens group can be corrected so that the focal lengths of the left and right photographing lenses can be matched with high accuracy. For example, it is necessary to measure each product and store it in the lens control device as correction data. There has been a problem that the creation of correction data for each product requires a lot of time and labor. In addition, there is a problem that it is difficult to cope with changes in characteristics of the taking lens and sensor over time.

  The present invention has been made in view of such circumstances, and the size of the subject in the left and right parallax images forming the stereoscopic image, that is, the right and left parallax images, is not required to create correction data. An object of the present invention is to provide a three-dimensional image photographing system that can accurately match the photographing magnifications of the two.

  In order to achieve the above object, the stereoscopic image capturing system according to claim 1 includes a right imaging unit that captures a right parallax image for forming a stereoscopic image, and a left parallax image for forming a stereoscopic image. Electronically at least one of a left parallax image captured by the left radiographing means and a left parallax image captured by the left radiographing means at a predetermined electronic zoom magnification. An electronic zoom means for enlarging or reducing the image, a right parallax image taken by the right photographing means, and a left parallax image obtained from the left photographing means, and based on the obtained parallax images on both sides Electronic zoom magnification changing means for changing the electronic zoom magnification in the electronic zoom means so that the sizes of the same subject in the parallax images on both sides coincide with each other. Stereoscopic imaging system according to claim.

  According to the present invention, the left and right parallax images photographed by the left and right photographing means are electronically enlarged / reduced by electronic zoom, and the electronic zoom magnification is set based on the actually obtained parallax image. Therefore, the size of the subject (the size of the image of the same subject) in the left and right parallax images can be accurately matched without considering the difference in the characteristics of the left and right optical systems and sensors. That is, it is possible to accurately match the shooting magnifications of the left and right shooting means when the electronic zoom is considered.

  The stereoscopic image capturing system according to a second aspect is the invention according to the first aspect, wherein the electronic zoom magnification changing unit includes a right parallax image acquired from the right imaging unit and a left parallax image acquired from the left imaging unit. Among the parallax images, for the parallax image that is enlarged or reduced by the electronic zoom unit, the parallax image that has been enlarged or reduced by the electronic zoom unit is acquired, and the acquired right-side parallax image and left-side parallax image are acquired. An error amount calculation means for extracting a difference image based on the difference between the right parallax image and the left parallax image based on the difference image; While changing the electronic zoom magnification in the zoom means, the error amount calculated by the error amount calculation means is acquired, and when the acquired error amount shows a minimum value It is characterized by comprising, a best electronic zoom magnification detecting means for setting the electronic zoom magnification in the electronic zoom means children zoom magnification.

  The present invention shows a specific mode for setting the electronic zoom magnification based on the left and right parallax images so that the size of the subject in the left and right parallax images matches. In particular, in the present invention, left and right parallax images after electronic enlargement / reduction by electronic zoom (when one parallax image of left and right parallax images is not electronically enlarged / reduction by electronic zoom, The electronic zoom magnification can be set using the parallax image obtained by the photographing means so that the size of the subject in the left and right parallax images actually matches.

  A stereoscopic image photographing system according to a third aspect is the invention according to the first or second aspect, wherein the right photographing unit includes a right optical system that forms an image on an imaging surface, and the left photographing unit includes: A left optical system that forms an image on an imaging surface, and the right optical system and the left optical system are optical systems in which a focal length is changed depending on a position of a zoom lens group that can move back and forth in the optical axis direction. The zoom lens group is controlled so that the focal lengths of the right optical system and the left optical system always coincide with each other.

  In the present invention, when the optical systems of the left and right photographing means can change the focal length by the variable power lens group, the focal lengths of the left and right optical systems are matched in the control of the variable power lens group. The case where it is performed is shown. That is, it shows a case where the focal lengths of the left and right optical systems are controlled to coincide with each other when the imaging magnification of the left and right imaging means can be changed by the focal length (optical zoom) of the optical system. Even if the focal length of the optical system is controlled in this way, it is difficult to completely match the photographing magnification (focal length) due to the individual difference between the left and right optical systems and the individual difference between the sensors. It is effective to correct the error by electronic zoom as in (2).

  The stereoscopic image capturing system according to claim 4, a right imaging unit that captures a right parallax image for forming a stereoscopic image, a left imaging unit that captures a left parallax image for forming a stereoscopic image, An optical system that forms an image on an imaging surface in the right imaging unit, a right optical system in which a focal length is changed depending on a position of a zoom lens group that is movable back and forth in the optical axis direction; and the left imaging unit An optical system that forms an image on the imaging surface, the left optical system in which the focal length is changed by the position of the variable power lens group that can move back and forth in the optical axis direction, and the right side photographed by the right imaging means A parallax image and a left-side parallax image captured by the left-side imaging unit are acquired, and based on the acquired parallax images on both sides, the size of the same subject image in the parallax images on both sides matches. light It is characterized by comprising a system with a the focal length changing means for changing the focal length by controlling the variable power lens unit of at least one of the optical system of the left optical system.

  According to the present invention, since the focal length of the optical system is changed based on the left and right parallax images actually obtained by the left and right photographing means, the difference in the characteristics of the left and right optical systems and sensors is completely taken into consideration. And the size of the subject in the left and right parallax images can be matched with high accuracy.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the focal length changing unit includes a right parallax image acquired from the right imaging unit and a left parallax acquired from the left imaging unit. An error amount calculating means for extracting a difference image based on a difference between the images and calculating an error amount representing a difference in size of the image of the same subject between the right parallax image and the left parallax image based on the difference image; The error amount calculated by the error amount calculation means was acquired while displacing the zoom lens group in at least one of the optical system and the left optical system, and the acquired error amount showed a minimum value. And a variable power lens group control means for setting the variable power lens group at the position at that time.

  The present invention shows a specific mode for changing the focal length of the optical system based on the left and right parallax images so that the size of the subject in the left and right parallax images matches. In the present invention, the zoom lens group of the optical system is moved to optically enlarge or reduce the parallax image to detect the position of the zoom lens group in which the size of the subject in the left and right parallax images matches. ing.

  According to a sixth aspect of the present invention, in the stereoscopic image photographing system according to the fourth aspect, the focal length changing unit includes a right parallax image acquired from the right photographing unit and a left parallax acquired from the left photographing unit. At least one parallax image among the images is electronically enlarged or reduced at a predetermined electronic zoom magnification, and a difference image is extracted based on a difference between the right parallax image and the left parallax image, and the right side image is extracted based on the difference image. An error amount calculating means for calculating an error amount indicating a difference in size between the parallax image and the left parallax image, and an error amount calculated by the error amount calculating means while changing the electronic zoom magnification A zoom lens group of at least one of the right optical system and the left optical system based on an electronic zoom magnification when the acquired error amount indicates a minimum value. It is characterized by comprising a variable power lens group control means for changing the focal length and control.

  The present invention shows a specific mode for changing the focal length of the optical system based on the left and right parallax images so that the size of the subject in the left and right parallax images matches. In the present invention, the parallax image is electronically enlarged or reduced by electronic zoom to obtain an electronic zoom magnification that matches the size of the subject in the left and right parallax images, and a variable magnification lens of the optical system based on the electronic zoom magnification The position of the group is controlled.

  According to the stereoscopic image capturing system according to the present invention, the size of the subject in the left and right parallax images forming the stereoscopic image, that is, the shooting of the left and right parallax images, is not required to create correction data. The magnification can be matched with high accuracy.

  Hereinafter, preferred embodiments of a stereoscopic image capturing system according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram showing an overall configuration of a stereoscopic image capturing system according to the present invention. The stereoscopic image shooting system shown in the figure includes two video cameras (TV cameras) 10A and 10B arranged in parallel in the left-right direction, and the video cameras 10A and 10B respectively have shooting lenses 12A and 12B constituting an optical system. In addition, the photographic lenses 12A and 12B are mounted by mounts, and the camera main bodies (camera heads) 14A and 14B constituting the imaging system are configured.

  In addition, the system shown in the figure includes a microprocessing unit (MPU) 16, a zoom operation unit 18, and the like as left and right lens control systems for controlling the optical systems (shooting lenses 12 A and 12 B) of the video cameras 10 A and 10 B. A constituent portion (described later) that is not surrounded by the alternate long and short dash line is provided. Furthermore, an image processing apparatus 20 is provided as part of the imaging system.

  In addition to the case where each component of the left and right lens control systems is configured as one or a plurality of devices separate from the photographing lenses 12A and 12B and the camera bodies 14A and 14B, a part or all of them are photographed. It may be incorporated in either the lens 12A, 12B or the camera body 14A, 14B as an integrated device.

  The optical system (photographing lens 12A), imaging system, and lens control system of the video camera 10A, and the optical system (photographing lens 12A), imaging system, and lens control system of the video camera 10B have corresponding components. In the following description, components related to the left video camera 10A are mainly described with the video camera 10A on the left side and the video camera 10B on the right side. Note that the configuration of the left and right video cameras 10A and 10B can be changed.

  The optical system (shooting lens 12A) of the left video camera 10A includes, for example, a fixed lens (group) 30A, a variable power lens (group) 32A, a focus lens (group) 34A, and the like. The focal length (optical zoom magnification) of the photographing lens 12A is changed by moving back and forth in the axial direction, and the focal position is adjusted by moving the focus lens 34A back and forth in the optical axis direction.

  The lens control system of the video camera 10A has a zoom control system that drives and controls the zoom lens 32A and a focus control system that drives and controls the focus lens 34A. The zoom control system includes a motor 40A that drives the zoom lens 32A, a motor drive circuit (motor driver) 42A that operates the motor 40A, and a position detector 44A that detects the position of the zoom lens 32A. The motor driver 42A is controlled by a control signal from the MPU 16, and drives the motor 40A based on the control signal.

  For example, the zoom operation unit 18 is provided with a zoom seesaw lever 46 that indicates a zooming direction (tele direction or wide direction) according to the operation direction and also indicates a zooming speed (speed) according to the operation amount. A voltage signal corresponding to the operation of the zoom seesaw 46 is supplied from the zoom operation unit 18 to the MPU 16 via the A / D converter 48 as a zooming command signal. A control signal indicating a zooming direction and a zooming speed is given from the MPU 16 to the motor driver 42A according to a zooming command signal given from the zoom operation unit 18, and the motor driver 42A drives the motor 40A according to the control signal. As a result, the zoom lens 32A is driven in a zooming direction corresponding to the operation direction of the zoom seesaw lever 46, and is driven at a zooming speed corresponding to the operation amount of the zoom seesaw lever 46, and the focal length of the left taking lens 12A is increased. Be changed.

  The position detector 44A is composed of, for example, a potentiometer, and detects the position of the zoom lens 32A between the tele end and the wide end as the zoom position voltage Va. This zoom position voltage Va is used as information indicating the focal length (optical zoom magnification) of the left photographic lens 12A. The zoom position voltage Va is given to the MPU 16 via an A / D converter (not shown).

  The focus control system of the video camera 10A includes a motor 50A that drives the focus lens 34A, a motor drive circuit (motor driver) 52A that operates the motor 50A, and a position detector 54A that detects the position of the focus lens 34A. Yes. A control signal is output from the MPU 16 to the motor driver 52A based on auto focus (AF) means (not shown), and the motor 50A is driven by the motor driver 52A according to the control signal. As a result, the focus lens 34A is driven to the in-focus position. The position detector 54A is composed of, for example, a potentiometer, detects the position of the focus lens 34A as a focus position voltage, and supplies the focus position voltage to the MPU 16 via an A / D converter (not shown).

  The imaging system of the video camera 10A is mainly mounted on the camera body 14A, and includes a CCD 60A, a CCD drive circuit (driver) 62A, a CDS circuit 64A, a reference signal generator (SSG) 66A, a signal processing circuit 68A, and the like. ing. The subject light that has passed through the photographing lens 12A is imaged on the light receiving surface (imaging surface) of the CCD 60A and converted into R, G, and B signal charges in amounts corresponding to the intensity of the light. The R, G, and B charges are read by a read pulse applied from the driver 62A, separated by the CDS circuit 64A, digitized by the signal processing circuit 68A, and subjected to known signal processing. As a result, the image signal (video signal) obtained by the signal processing circuit 68A is sent from the camera body 14A to the image processing apparatus 20 described later. Timing signals from the SSG 66A are respectively added to the driver 62A, the CDS circuit 64A, and the signal processing circuit 68A, and the circuits are synchronized.

  On the other hand, for the video camera 10B on the right side, the optical system (shooting lens 12B) includes a fixed lens (group) 30B, a variable power lens (group) 32B, a focus lens (group) 34B, etc., and the lens control system is And a zoom control system for driving and controlling the zoom lens 32B and a focus control system for driving and controlling the focus lens 34B. The zoom control system includes a motor 40B that drives the zoom lens 32B, a motor drive circuit (motor driver) 42B that operates the motor 40B, and a position detector 44B that detects the position of the zoom lens 32B. The focus control system includes a motor 50B that drives the focus lens 34B, a motor drive circuit (motor driver) 52B that operates the motor 50B, and a position detector 54B that detects the position of the focus lens 34B. The imaging system is mainly composed of a CCD 60B, a CCD drive circuit (driver) 62B, a CDS circuit 64B, a reference signal generator (SSG) 66B, a signal processing circuit 68B and the like mounted on the camera body 14B. The configuration of the optical system, lens control system (zoom control system and zoom control system), and imaging system in the right video camera 10B is the same as that of the left video camera 10A described above. The imaging process in the imaging system is the same as that of the video camera 10A.

  On the other hand, zoom control in the zoom control system of the right video camera 10B is different from that of the video camera 10A. The motor driver 42B is driven and controlled based on the error in the left and right zoom positions. The motor driver 42B changes the left optical system (photographing lens 10A) driven in advance by operation of the zoom seesaw lever 46 of the zoom operation unit 18. The variable magnification lens 32B is driven so as to reduce the error in the focal length (optical zoom magnification) of the left and right optical systems caused by the movement of the magnification lens 32A. In other words, the left side optical system (photographing lens 10A) is the master side and the right side optical system (photographing lens 10B) is the slave side, and the slave side variable power lens 32B follows the movement of the master side variable power lens 32A. Thus, an error in the focal length of the left and right optical systems is prevented. However, in reality, an error in focal length occurs in the left and right optical systems due to individual differences between the left and right optical systems and individual differences between the position detectors 44A and 44B.

  Specifically, the position detector 44B detects the position of the zoom lens 32B and outputs it as a zoom position voltage Vb. The zoom position voltage Vb is the focal length (optical zoom magnification) of the right taking lens 10B. ) Is given to the MPU 16 via an A / D converter (not shown). The MPU 16 outputs a control signal to the motor driver 42B based on the difference between the zoom position voltage Va obtained from the left position detector 44A and the zoom position voltage Vb obtained from the right position detector 44B. . The control signal moves the zoom lens 32A in the zooming direction where the difference between the zoom position voltage Va and the zoom position voltage Vb is small, and the motor driver 42B issues a command to increase the zooming speed as the difference increases. To give. As a result, the zoom lens 32B of the right optical system moves following the zoom lens 32A of the left optical system.

  When the zoom operation unit 18 outputs a zooming command signal for instructing a target zoom position, the zoom lens 32B of the right optical system is moved to the movement of the zoom lens 32A of the left optical system as described above. Instead of tracking, the zoom lenses 32A and 32B of the left and right optical systems may be controlled separately so that the zoom position commanded by the zooming command signal is obtained. In addition, as described above, even when the zoom operation unit 18 outputs a zooming command signal for commanding the target zoom speed (zooming direction and zooming speed (speed)), the zoom speed commanded by the zooming command signal is used. The variable power lenses 32A and 32B of the left and right optical systems may be controlled separately so that In this case, there may be a relatively large difference in the focal length (optical zoom magnification) of the optical system, but the difference can be corrected by electronic zoom as will be described later.

  Next, the image processing apparatus 20 will be described. The image processing apparatus 20 mainly includes an image processing unit 70 and an electronic zoom circuit 72. As described above, the image signal (video signal) obtained by the imaging system of the left video camera 10A is sent from the left camera body 14A to the image processing device 20 and input to the image processing device 20 as the input signal A. Similarly, an image signal (video signal) obtained by the imaging system of the right video camera 10B is sent from the right camera body 14B to the image processing device 20 and input to the image processing device 20 as an input signal B.

  In the image processing apparatus 20, the left video signal captured as the input signal A is output from the image processing apparatus 20 as the output signal A as it is and is captured by the image processing unit 70. On the other hand, the right video signal input as the input signal B is input to the electronic zoom circuit 72, and the image of each frame (each field) of the video signal is enlarged or reduced by the electronic zoom processing. Yes. As will be described later, the magnification of the electronic zoom (electronic zoom magnification) in the electronic zoom circuit 72 is determined by the image processing unit 70 and is set by an instruction signal from the image processing unit 70. The video signal subjected to the electronic zoom processing by the electronic zoom circuit 72 is output from the image processing apparatus 20 as an output signal B and is taken into the image processing unit 70.

  The left video signal and the right video signal output as the output signal A and the output signal B from the image processing device 20 are respectively the left (left-eye) parallax images that the system forms a stereoscopic image (stereoscopic image). And the right side (right eye) parallax image are finally output as video signals, and the left and right parallax images taken by this system have the same shooting magnification as that of the left optical system (shooting lens 10A). It is changed depending on the optical zoom magnification according to the focal length of the right optical system (photographing lens 10B) and the electronic zoom magnification of the image processing device 20. In this system, shooting is performed with this system by correcting the error in the shooting magnification between the left and right parallax images according to the optical zoom magnification of the optical system with the electronic zoom magnification of the electronic zoom performed on the right parallax image. The left and right parallax images are made to have the same shooting magnification. That is, the size of the image of the same subject in each of the left parallax image and the right parallax image (the length on the image with respect to the length of the subject in real space) is matched with high accuracy.

  As will be described in detail later, the image processing unit 70 captures an image (parallax image) for one frame (one screen) from the left video signal output as the output signal A, and outputs the image (parallax image) as the output signal B. An image (parallax image) for one frame is captured from the video signal on the right side, and the images are compared so that the subject size (the size of the same subject image) in the parallax images is equal. The electronic zoom magnification in the zoom circuit 72 is changed.

  Note that the image processing unit 70 provides synchronization signals to the SSGs 66A and 66B in the left and right camera bodies 14A and 14B, and synchronizes the timings of the timing signals output from the SSGs 66A and 66B, so that the left video signal and the right video signal are synchronized. We are trying to synchronize.

  FIG. 2 is a principal block diagram showing an example of a specific configuration of the electronic zoom circuit 72. The electronic zoom circuit 72 mainly includes a reference signal generator (SSG) 100, a write buffer 102, a frame memory 104, a read buffer 106, a write address generation circuit 108, a read address generation circuit 110, and the like.

  In FIG. 1, the data of the right video signal input from the right video camera 10 </ b> B (camera body 14 </ b> B) to the electronic zoom circuit 72 is sequentially input to the write buffer 102. The data temporarily stored in the write buffer 102 is addressed by the write address generation circuit 108 and written into the frame memory 104 based on a write timing signal from the SSG 100. The image data written in the frame memory 104 is read according to the read address specified by the read address generation circuit 110 and is output via the read buffer 106. The SSG 100 adjusts the timing so that the write operation and the read operation are alternately repeated. Further, when the SSG 100 adds the read address to the frame memory 104, the SSG 100 adjusts the read start address, the read timing, and the like based on the electronic zoom magnification instructed from the image processing unit 70, so that the instructed electronic zoom magnification is obtained. The input image is enlarged or reduced. The configuration of the electronic zoom circuit 72 shown in FIG. 2 is an example, and other configurations may be used.

  Next, processing in the image processing unit 70 will be described with reference to the flowchart of FIG. The image processing unit 70 captures an image (luminance data) for one screen of the video signal input from the left video camera 10A as the input signal A (step S10). Note that the image captured in step S10 is referred to as an image A. Subsequently, the electronic zoom magnification of the electronic zoom circuit 72 is set to 0.95 (step S12), and the variable n is set to 0 (step S14).

  Next, the image processing unit 72 takes in an image (luminance data) for one screen of a video signal input from the right video camera 10B as the input signal B and subjected to electronic zoom processing by the electronic zoom circuit 72 (step S16). Note that the image captured in step S16 is referred to as an image B. Then, the difference image C is obtained by extracting the difference between the image A and the image B (step S18). That is, the absolute value (| A−B |) of the difference between the pixel values (luminance values) of the corresponding pixels of the image A and the image B is obtained, and the image obtained thereby is defined as a difference image C. Next, the difference image C is binarized as 1 if the pixel value of each pixel of the difference image C is equal to or greater than a predetermined threshold value, and 0 if it is less than the threshold value (step S20). And the area of the pixel which shows 1 in the binarized difference image C is calculated | required, and the value of the area is set to Area (n) (step S22). The area Area (n) is an error amount that represents a difference in image size between the same subject in the image A and the image B.

Next, 1 is added to the variable n. That is, n = n + 1 is set (step S24). Subsequently, the electronic zoom magnification in the electronic zoom circuit 72 is
0.95+ (0.01 × n)
(Step S26). Then, it is determined whether or not the electronic zoom magnification is less than 1.05, that is, whether or not n is less than 10 (step S28).

  If YES is determined in step S28, the process returns to step S16, and the area of the difference image C when 1 is added to n is obtained. That is, by changing n from 0 to 9 and changing the electronic zoom magnification by 0.95 by 0.01, the area Area (n) of the difference image C at each electronic zoom magnification is calculated.

  If NO is determined in step S28, that is, if the electronic zoom magnification is 1.05, then the area Area (n) when n is 0 to 9 is the minimum value. A thing is detected (step S30). Then, the electronic zoom magnification when the area Area (n) becomes the minimum value is set as the electronic zoom magnification of the electronic zoom circuit 72 (step S32).

  By appropriately repeating the above processing, the electronic zoom magnification in the electronic zoom circuit 72 is changed so that the size of the image of the same subject in the left parallax image and the right parallax image always matches.

  In the flowchart shown in FIG. 3, when the electronic zoom magnification is changed, the initial value of the electronic zoom magnification is set to 0.95 in step S12. However, it is not always necessary to set it to 0.95. For example, the area Area (n) is obtained by setting the electronic zoom magnification set in step S32 when the process of the present flowchart was executed as the initial value as it is as the initial value, and increasing or decreasing the electronic zoom magnification in the electronic zoom circuit 72 with respect to the initial value. The electronic zoom magnification in the electronic zoom circuit 72 may be changed to the electronic zoom magnification when the minimum value is obtained. In addition, the electronic zoom magnification is changed in the direction in which the area Area (n) decreases with respect to the initial value, and the electronic zoom magnification in the electronic zoom circuit 72 is changed to the electronic zoom magnification when the area Area (n) is minimized. May be set.

  Also, the processing of the flowchart shown in FIG. 3 may be performed at an arbitrary timing (continuous or at a predetermined time interval), or when the focal length (optical zoom magnification) of the left and right optical systems changes. You may make it carry out.

  As described above, in the above-described embodiment, the electronic zoom process is performed on the right video signal, but by performing the electronic zoom process on the left video signal instead of the right video signal, or Alternatively, the size of the subject in the parallax images on both sides may be matched by performing electronic zoom processing on the left and right video signals.

  In the above-described embodiment, the image processing unit 70 of the image processing apparatus 20 captures an image of the video signal (right video signal) that has been electronically zoomed by the electronic zoom circuit 72, and the electronic zoom circuit is based on the image. Although the electronic zoom magnification of 72 is set, the present invention is not limited to this. An image of the left and right video signals before electronic zoom processing by the electronic zoom circuit 72 may be captured, and an appropriate electronic zoom magnification may be obtained based on the image to set the electronic zoom magnification in the electronic zoom circuit 72.

  In the above embodiment, the electronic zoom is used to match the size of the subject in the left and right parallax images with high accuracy. However, the focal length (optical zoom) of at least one of the left and right optical systems is set. Correction may be made so that the size of the subject in the left and right parallax images matches with high accuracy. For example, when the left optical system (photographing lens 10A) is controlled as the master side and the right optical system (photographing lens 10B) is controlled as the slave side, the position of the zoom lens 32A of the left optical system changes and the focal length changes. Is changed, the zoom lens 32B of the right optical system is moved to a position corresponding to the position of the zoom lens 32A. Subsequently, images of the video signals (left and right parallax images) output from the left camera body 14A and the right camera body 14B are acquired by a processing unit corresponding to the image processing unit 70, and the left and right images are the same as in the above embodiment. The difference between these parallax images is extracted to determine the area Area (error amount) of the difference image. Then, the zoom lens 32B is set at a position where the area Area is the minimum value. Here, the position of the variable magnification lens 32B where the area Area is the minimum value is the position where the area Area of the difference image is obtained while actually moving the variable magnification lens 32B, and the area Area becomes the minimum value (minimum value). Can be detected as Alternatively, at least one parallax image, for example, the right parallax image is electronically enlarged / reduced by electronic zoom in the processing unit that has acquired the left and right parallax images, and the subject in the left and right parallax images is the same as in the above embodiment. It is also possible to obtain an electronic zoom magnification with the same size and to displace the zoom lens 32B so as to change the focal length (optical zoom magnification) of the left optical system by an amount corresponding to the electronic zoom magnification. it can.

  Further, the present invention is applicable even when the characteristics (types) of the left and right optical systems are different, and when correcting the size of the subject in the left and right parallax images using the electronic zoom. Can be effectively applied even when the focal length of the optical system is not variable.

  In addition, as shown in FIG. 1, the variable magnification lenses 32A and 32B of the left and right optical systems are not driven separately by the individual motors 40A and 40B, but are linked to one motor 120 as shown in FIG. Even in the configuration in which the zoom lenses 32A and 32B are driven, a mode in which the size of the subject in the left and right parallax images captured by the left and right video cameras 10A and 10B is corrected by electronic zoom as in the above embodiment. Can be applied. 4, components having the same or similar functions as those in FIG. 1 are denoted by the same reference numerals. The difference from FIG. 1 is that the left and right variable magnification lenses 32A and 32B are connected to one motor 120 (not shown). The motor 120 is connected by a mechanism, and the operation of the motor 120 is controlled by a single motor driver 122. The motor 120 and the driver 122 are connected to the motor 40A of the left video camera 10A shown in FIG. It is controlled by the MPU 16 similarly to the driver 42A.

FIG. 1 is a diagram showing an overall configuration of a stereoscopic image capturing system according to the present invention. FIG. 2 is a principal block diagram showing an example of a specific configuration of the electronic zoom circuit. FIG. 3 is a flowchart showing a processing procedure in the image processing unit. FIG. 4 is a diagram showing an overall configuration of another embodiment of the stereoscopic image capturing system according to the present invention.

Explanation of symbols

10A, 10B ... Video camera, 12A, 12B ... Shooting lens, 14A, 14B ... Camera body, 16 ... Microprocessing device, 18 ... Zoom operation unit, 20 ... Image processing device, 32A, 32B ... Variable magnification lens (group), 40A, 40B ... Motor, 42A, 42B ... Motor drive circuit (motor driver), 44A, 44B ... Position detector, 60A, 60B ... CCD, 62A, 62B ... CCD drive circuit (driver), 64A, 64B ... CDS circuit, 66A, 66B ... reference signal generator (SSG), 68A, 68B ... signal processing circuit, 70 ... image processing unit, 72 ... electronic zoom circuit

Claims (6)

A right side photographing means for photographing a right side parallax image for forming a stereoscopic image;
A left-side photographing means for capturing a left-side parallax image for forming a stereoscopic image;
Electronic zoom means for electronically enlarging or reducing at least one of the right parallax image photographed by the right photographing means and the left parallax image photographed by the left photographing means at a predetermined electronic zoom magnification When,
The right-side parallax image captured by the right-side imaging unit and the left-side parallax image obtained from the left-side imaging unit are acquired, and the size of the same subject in the parallax images on both sides is acquired based on the acquired parallax images on both sides. Electronic zoom magnification changing means for changing the electronic zoom magnification in the electronic zoom means so as to match,
A stereoscopic image shooting system comprising: The electronic zoom magnification changing means includes:
Of the right-side parallax image acquired from the right-side imaging unit and the left-side parallax image acquired from the left-side imaging unit, a parallax image that is enlarged or reduced by the electronic zoom unit is enlarged or reduced by the electronic zoom unit. A difference image is extracted based on the difference between the acquired right parallax image and the left parallax image, and based on the difference image, the same parallax image and the left parallax image are obtained. An error amount calculating means for calculating an error amount representing a difference in image size;
While changing the electronic zoom magnification in the electronic zoom means, the error amount calculated by the error amount calculation means is acquired, and the electronic zoom magnification when the acquired error amount shows the minimum value is obtained in the electronic zoom means. The best electronic zoom magnification detection means to set as the electronic zoom magnification;
The stereoscopic image capturing system according to claim 1, comprising: The right imaging unit includes a right optical system that forms an image on the imaging surface, and the left imaging unit includes a left optical system that forms an image on the imaging surface,
The right optical system and the left optical system are optical systems in which a focal length is changed depending on a position of a variable power lens group that can move back and forth in the optical axis direction, and the focal length of the right optical system and the left optical system The three-dimensional image capturing system according to claim 1 or 2, wherein the variable power lens group is controlled so as to always match. A right side photographing means for photographing a right side parallax image for forming a stereoscopic image;
A left-side photographing means for capturing a left-side parallax image for forming a stereoscopic image;
An optical system that forms an image on the imaging surface in the right imaging means, the right optical system in which the focal length is changed according to the position of the variable power lens group that can be moved back and forth in the optical axis direction;
An optical system that forms an image on an imaging surface in the left imaging unit, the left optical system in which a focal length is changed depending on a position of a zoom lens group that is movable back and forth in the optical axis direction;
The right-side parallax image captured by the right-side imaging unit and the left-side parallax image captured by the left-side imaging unit are acquired, and based on the acquired parallax images on both sides, the same subject image in the parallax images on both sides A focal length changing means for changing a focal length by controlling a variable power lens group of at least one of the right optical system and the left optical system so that the sizes of the right optical system and the left optical system match.
A stereoscopic image shooting system comprising: The focal length changing means is
A difference image is extracted based on a difference between the right parallax image acquired from the right imaging unit and the left parallax image acquired from the left imaging unit, and the same subject in the right parallax image and the left parallax image is extracted based on the difference image. An error amount calculating means for calculating an error amount representing a difference in image size;
While displacing the variable power lens group in at least one of the right optical system and the left optical system, the error amount calculated by the error amount calculation unit is acquired, and the acquired error amount has a minimum value. A zoom lens group control means for setting the zoom lens group at the position shown,
The stereoscopic image capturing system according to claim 4, further comprising: The focal length changing means is
At least one of the right parallax image acquired from the right imaging unit and the left parallax image acquired from the left imaging unit is electronically enlarged or reduced at a predetermined electronic zoom magnification, and the right parallax image is displayed. An error amount calculating means for extracting a difference image based on a difference between the left parallax image and the left parallax image and calculating an error amount representing a difference in size between the right parallax image and the left parallax image based on the difference image When,
While changing the electronic zoom magnification, the error amount calculated by the error amount calculation means is acquired, and the right optical system and the left side are based on the electronic zoom magnification when the acquired error amount indicates a minimum value. A variable power lens group control means for controlling the variable power lens group of at least one of the optical systems to change the focal length;
The stereoscopic image capturing system according to claim 4, further comprising:

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