JP2012199621A - Compound-eye imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compound-eye imaging apparatus capable of obtaining a high-quality image in both a tele-side and a wide side, with reduced overall power consumption.SOLUTION: The compound-eye imaging apparatus includes: a zoom lens optical system 1; installed in the periphery thereof, a plurality of fixed focus lens optical systems 2R, 2L; trapezoid processors 5R, 5L; an image composer 6; and a controller 9. When an input zoom position is nearer to the tele-side than a predetermined zoom position, the input zoom position is set to be a zoom position of the zoom lens optical system 1, and from the image imaged by the zoom lens optical system 1, an image having a view angle based on the set zoom position is generated. When an input zoom position is nearer to the wide side than the predetermined zoom position, the zoom position of the zoom lens optical system 1 is set to be a wide end. The image imaged by the zoom lens optical system 1 is composed with an image on which keystone correction is made by the trapezoid processors 5R, 5L, so that an image having the view angle based on the set zoom position is generated from the composite image.

Description

  The present invention relates to a compound eye imaging device having a zoom function.

  Conventionally, in order to obtain a wide-angle image in a digital camera or a digital video camera, it is common to take a picture using a wide-angle lens. However, the wide-angle lens is expensive and has a problem that the image quality of the peripheral portion is deteriorated due to large distortion. In view of this, there is known a method for realizing wide-angle imaging with low distortion at low cost by photographing a wide-angle subject area divided into a plurality of imaging systems and correcting and synthesizing the captured images. (Patent Documents 1 and 2) In this method, by making the viewpoints of a plurality of optical systems substantially coincide with each other, it is possible to easily synthesize the captured images only by performing trapezoidal correction and overlap processing blending.

  Digital cameras and digital video cameras are often equipped with a zoom function. In particular, in the case of digital video cameras, it is required to change seamlessly during shooting from the tele side to the wide side. As a method for realizing the zoom function, there are known an optical zoom that changes a focal length by physically moving a lens, and a digital zoom that is realized by enlarging and reducing an image signal using a fixed focus lens. Since the digital zoom is enlarged and reduced by signal processing, the image quality is deteriorated. Therefore, the optical zoom is generally higher in image quality.

JP 2007-288568 A JP 2007-295113 A

  However, since the compound-eye imaging devices described in Patent Documents 1 and 2 use a fixed focus lens, a digital zoom must be used to realize the zoom function. In this case, there is a problem that the image quality is deteriorated because the enlargement ratio increases especially toward the telephoto side.

    In addition, the compound-eye imaging apparatus operates a plurality of imaging elements and signal processing systems, and thus has a problem that power consumption is larger than that of a monocular imaging apparatus. In view of such a problem, an object of the present invention is to provide a compound eye imaging apparatus that can obtain high-quality images on both the tele side and the wide side and reduce the overall power consumption.

  One aspect of the present invention is a compound-eye imaging device, which includes a zoom lens optical system (1), and a plurality of fixed focus lens optical systems (2R, 2L) installed around the zoom lens optical system (1). A trapezoid processing unit (5R, 5L) that corrects each keystone (SL, SR) photographed by the plurality of fixed focus lens optical systems (2R, 2L), and an input zoom position is more telescopic than a predetermined zoom position. If the input zoom position is on the wide side of the predetermined zoom position, the input zoom position is set to the zoom position of the zoom lens optical system (1). The control unit (9) for setting the zoom position of 1) to the wide end, and when the set zoom position is on the tele side with respect to the predetermined zoom position, the zoom lens optical system (1) takes a picture. An image of a viewing angle based on the set zoom position is created from the image, and when the set zoom position is on the wide side with respect to the predetermined zoom position, the image was taken by the zoom lens optical system (1) An image composition unit (6) that composes an image and an image that has been trapezoidally corrected by the trapezoid processing unit (5R, 5L), and creates an image with a viewing angle based on a zoom position set from the composite image; The gist is that the field of view of the plurality of fixed focus lens optical systems (2R, 2L) overlaps with part of the field of view at the wide end in the zoom lens optical system (1).

  The focal length at the wide end of the zoom lens optical system (1) is preferably equal to the focal length of each of the plurality of fixed focus lens optical systems (2R, 2L).

  When the input zoom position is on the tele side with respect to the predetermined zoom position, the control unit (9) preferably stops imaging using the plurality of fixed focus lens optical systems (2R, 2L). .

  According to the compound eye imaging apparatus of the present invention, a high-quality image using an optical zoom can be obtained on the telephoto side, and a wide-angle and high-quality image using a compound eye can be obtained on the wide side. Further, the power consumption of the entire compound-eye imaging device can be reduced by stopping the imaging using the fixed-focus lens optical system during telephoto shooting.

It is a block diagram of the compound eye imaging device which concerns on one Embodiment of this invention. It is explanatory drawing of the viewing angle of the to-be-photographed object in the compound eye imaging device of this embodiment. It is a flowchart which shows the process in the compound eye imaging device of this embodiment. It is a block diagram which shows the example of the optical system in other embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a configuration diagram of a compound eye imaging apparatus according to the present embodiment. FIG. 2 is an explanatory diagram of the viewing angle of the subject in the compound-eye imaging device of the present embodiment, (a) is a diagram showing the relationship between viewing angles on a plane including optical axes in different directions, and (b) It is an example of the result of having combined the image image | photographed with each below-mentioned optical system 1, 2R, 2L.

  As shown in FIG. 1, the compound-eye imaging device 20 of this embodiment is installed behind the zoom lens optical system 1, the two fixed focus lens optical systems 2R, 2L, and the optical systems 1, 2R, 2L. The image sensors 3C, 3R, and 3L are provided, and configured to acquire at least one of a still image and a moving image.

  A zoom lens optical system (hereinafter referred to as a main eye) 1 is provided in the center between the fixed focus lens optical systems 2R and 2L. The main eye 1 is in charge of the imaging area of the viewing angle AC at the wide end (see FIG. 2A). An optical zoom mechanism (not shown) that varies the zoom position (focal length) by physical movement of the lens is provided. This optical zoom mechanism is controlled by the control unit 9.

  The zoom position of the main eye 1 depends on the zoom position (input zoom position) input from the zoom input means 10. That is, when the input zoom position is on the tele side with respect to the predetermined zoom position, the zoom position of the main eye 1 is set to the input zoom position. In this case, the image composition unit 6 operates in a tele processing mode (described later). On the other hand, when the input zoom position is on the wide side with respect to the predetermined zoom position, the zoom position of the main eye 1 is set to the wide end. In this case, the image composition unit 6 operates in a wide processing mode (described later).

  The fixed-focus lens optical systems 2R and 2L are provided on the left and right sides of the main eye 1 as the center. The fixed focus lens optical systems 2R and 2L are in charge of the imaging areas of the viewing angles AR and LR, respectively. Unlike the main eye 1, the focal lengths of the fixed focus lens optical systems 2R and 2L are fixed.

  As shown in FIG. 2A, the optical axes OR and OL of the fixed focus lens optical systems 2R and 2L are inclined in directions opposite to the optical axis OC of the main eye 1. For image synthesis, the field of view of each lens 2 </ b> R, 2 </ b> L overlaps with a part of the field of view at the wide end of the main eye 1. For example, as shown in FIG. 2B, when the zoom position of the main eye 1 is at the wide end, a part of the image SC and the images SR and SL of the lens optical systems 2R and 2L overlap with each other, and the overlapping region (Blend region) BR and BL are formed.

  From the viewpoint of facilitating the composition processing of the captured images by the optical systems 1, 2R, and 2L, the focal length of the wide end of the main eye 1 and the focal length of the fixed focus lens optical systems 2R and 2L are equal to each other. desirable. Further, it is preferable that the viewpoints of all the optical systems 1, 2R, and 2L are installed so as to substantially coincide. Specifically, the matching of viewpoints means that the positions of the entrance pupils of the imaging optical systems (zoom lens optical system and fixed focus lens optical system) are substantially matched.

  Image sensors 3C, 3R, and 3L such as CCDs are provided behind the main eye 1 and fixed focus lens optical systems 2R and 2L, respectively, and convert optical information from each lens into image signals. As the image sensors 3C, 3R, 3L, known ones are applied.

  The electronic signals converted by the image sensors 3C, 3R, and 3L are sent to the signal processing units 4C, 4R, and 4L, respectively, and perform signal processing such as Bayer processing, noise removal, white balance adjustment, and gamma processing. The image signal processed by the signal processing unit 4C is sent to the image synthesis unit 6. On the other hand, the image signals processed by the signal processing units 4R and 4L are sent to the keystone correction units 5R and 5L, respectively.

  The trapezoid correction units 5R and 5L perform keystone correction on the image signals from the signal processing units 4R and 4L. The image signals output from the signal processing units 4C, 4R, and 4L are obtained by the optical systems 1, 2R, and 2L having different optical axis directions. Therefore, even if it is originally the same distance, it appears to be contracted as it is away from the optical axis OC on each image. In the trapezoidal correction according to the present embodiment, a process for correcting the distance between pixels is performed on an image captured by the fixed focus lens optical systems 2R and 2L before performing a synthesis process for joining the images.

  The trapezoidal correction unit 5R performs keystone correction on each image signal (image SR) obtained by the signal processing unit 4R so that the image is on the same plane as the image SC of the main eye 1. Similarly, the trapezoidal correction unit 5L also performs keystone correction on each image signal (image SL) obtained by the signal processing unit 4L so as to be an image on the same plane as the image SC of the main eye 1. As a result, the overall shape of the images SR and SL is a trapezoid shown in FIG.

  Image signals from the trapezoid correction units 5R and 5L and the signal processing unit 4C are input to the image synthesis unit 6. The image processing of the image composition unit 6 has two modes of wide processing and tele processing. These modes are switched according to a control signal from the control unit 9 (that is, the zoom position of the main eye 1).

  The wide processing mode is a mode in which a wide-angle image is generated using images obtained by the optical systems 1, 2R, and 2L. In this mode, the image composition unit 6 performs the blending process of the image SC and the image SR in the overlapping area BR and the blending process of the image SC and the image SL in the overlapping area BL to synthesize the images SC, SR, and SL. Thereafter, the image composition unit 6 performs a process of cutting out an image having a viewing angle corresponding to the zoom position (input zoom position) input from the zoom input unit from the composite image. That is, a composite image is once created under the viewing angle at the wide end, and an image with a viewing angle corresponding to the input zoom position is cut out from the composite image. Further, the image composition unit 6 appropriately enlarges / reduces the clipped image and outputs an image with a predetermined resolution.

  The tele processing mode is a mode for generating a telephoto image using only the image SC obtained by the main eye 1. In this mode, since the zoom position of the main eye 1 continuously changes according to the input zoom position, the image composition unit 6 outputs the obtained image SC as it is. In addition, when an input zoom position that is insufficient for the optical zoom is input, the obtained image SC may be cut out according to the input zoom position and subjected to enlargement / reduction processing to output an image with a predetermined resolution.

  For the image processing in the trapezoid correction units 5R and 5L and the image composition unit 6, for example, a known processing method such as the image processing described in Patent Document 1 can be applied.

  In any of the above modes, the image signal output from the image composition unit 6 is input to the display unit 7 and the storage unit 8. The display unit 7 displays an image based on the input image signal. The storage unit 8 stores the input image signal as image data. The storage unit 8 stores programs and parameters for executing various controls performed by the control unit 9. In addition, a predetermined zoom position (to be described later) for determining the above-described image processing mode is also stored.

  The zoom input means 10 is a terminal device that inputs a zoom position desired by the user, and outputs a signal corresponding to the input zoom position to the control unit 9. As this zoom input means 10, a known one is applied.

  Based on the input zoom position set by the zoom input means 10, the control unit 9 performs processing related to the above-described image processing mode on the main eye 1, the image composition unit 6, and the like. This process will be described with reference to the flowchart of FIG.

  First, when a zoom position is input from the zoom input means 10 by a user's operation (step S1), the control unit 9 performs the input zoom position and a predetermined zoom stored in the storage unit 8 in advance. The position is compared (step S2). In this comparison, when the input zoom position is on the tele side with respect to the predetermined zoom position (YES in step S2), the process proceeds to step S3, and the tele processing mode is executed. On the other hand, when the input zoom position is on the wide side with respect to the predetermined zoom position (NO in step S2), the process proceeds to step S6, and the wide processing mode is executed.

  As described above, the tele processing mode is executed from step S3. First, in step S <b> 3, the control unit 9 sets the zoom position of the main eye 1 to the zoom position input from the zoom input unit 10. Next, the control unit 9 stops the operations of the image sensors 3R and 3L, the signal processing units 4R and 4L, and the trapezoid correction units 5R and 5L (step S4). Here, it is assumed that the image pickup devices 3R and 3L, the signal processing units 4R and 4L, and the trapezoid correction units 5R and 5L have a mechanism for controlling whether or not to operate according to a control signal from the control unit 9. For example, a mechanism capable of turning on / off the drive power supply or the operation clock by the control unit 9 may be used, or an operation mode switching mechanism may be provided.

  Next, in step S5, the control unit 9 sends a control signal to the image composition unit 6 so as to perform image processing in the tele processing mode. In response to this, the image synthesizing unit 6 outputs an image having a desired resolution using only the image signal from the signal processing unit 4C, and ends the series of processes.

  On the other hand, the wide processing mode is executed from step S6. First, in step S6, the control unit 9 sets the zoom position of the main eye 1 to the wide end. Next, the control unit 9 operates the image pickup devices 3R and 3L, the signal processing units 4R and 4L, and the trapezoid correction units 5R and 5L to obtain images from the optical systems 1, 2R, and 2L, and the fixed focus lens optical system. The above trapezoidal correction is performed on each image obtained by 2R and 2L (step S7).

  In step S8, the control unit 9 sends a control signal to the image composition unit 6 so as to perform image processing in the wide processing mode. At the same time, the control unit 9 also sends to the image composition unit 6 a cutout signal for instructing a region to be cut out in the generated composite image based on the zoom position input from the zoom input means 10. The image synthesis unit 6 synthesizes the images from the trapezoid correction units 5R and 5L and the signal processing unit 4C, and cuts out a region having a position and a viewing angle corresponding to the cut-out signal from the synthesized image so as to obtain a desired resolution. The image is output after being enlarged or reduced.

  According to the compound eye imaging device of the present embodiment, a high-quality image using optical zoom can be obtained on the telephoto side, and a wide-angle and high-quality image using compound eyes can be obtained on the wide side.

  Further, the power consumption of the entire compound-eye imaging device can be reduced by stopping the imaging using the fixed-focus lens optical system during telephoto shooting.

  Note that the compound eye imaging device of the present embodiment is not limited to three eyes. For example, as shown in FIG. 4, it may be composed of a five-lens optical system in which fixed focus lenses 2a, 2b, 2c, and 2d are arranged at the upper left, upper right, lower left, and lower right so as to surround the main eye 1C. May be the number.

  In addition, when each optical system 1, 2R, 2L has distortion, the signal processing units 4C, 4R, 4L may correct the distortion before performing trapezoidal correction and image synthesis.

  Furthermore, in the above description, the focal lengths of the wide end of the main eye 1 and the fixed focus lens optical system are equal, but these focal lengths may be different. Even in this case, the keystone correction units 5R and 5L or the image synthesis unit 6 can synthesize the single wide-angle image.

  According to the present invention, a compound-eye imaging device such as a digital still camera or a digital video camera with a zoom function that is inexpensive, has high image quality, and consumes low power can be realized.

  DESCRIPTION OF SYMBOLS 1 ... Zoom lens optical system, 2R, 2L, 2a, 2b, 2c, 2d ... Fixed focus lens optical system, 3C, 3R, 3L ... Imaging element, 4C, 4R, 4L ... Signal processing , 5R, 5L ... trapezoid correction unit, 6 ... image composition unit, 7 ... display unit, 8 ... storage unit, 9 ... control unit, 10 ... zoom input means, AC AR, AL: Viewing angle of field of lens optical system, SC, SL, SR: Captured image, BL, BR: Blend area (blend area)

Claims (3)

Zoom lens optics,
A plurality of fixed focus lens optical systems installed around the zoom lens optical system;
A trapezoid processing unit that corrects a keystone of each image captured by the plurality of fixed focus lens optical systems;
If the input zoom position is on the tele side of the predetermined zoom position, the input zoom position is set to the zoom position of the zoom lens optical system, and the input zoom position is wider than the predetermined zoom position. A control unit for setting the zoom position of the zoom lens optical system to the wide end;
When the set zoom position is on the tele side with respect to the predetermined zoom position, an image with a viewing angle based on the set zoom position is created from the image photographed by the zoom lens optical system and set. When the zoom position is wider than the predetermined zoom position, the image captured by the zoom lens optical system and the image corrected by the trapezoid processing unit are combined and set from the combined image. An image composition unit that creates an image of a viewing angle based on the zoom position,
The compound-eye imaging apparatus, wherein a field of view of the plurality of fixed focus lens optical systems overlaps a part of the field of view at the wide end in the zoom lens optical system.
2. The compound eye imaging apparatus according to claim 1, wherein a focal length at the wide end of the zoom lens optical system is equal to each focal length of the plurality of fixed focus lens optical systems.
  3. The control unit according to claim 1, wherein when the input zoom position is on a tele side with respect to the predetermined zoom position, the control unit stops imaging using the plurality of fixed focus lens optical systems. The compound eye imaging device described.

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