JP2010028198A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of imaging an image without any slope, even if the image is photographed by a device in a hand-held position such as a digital camera. <P>SOLUTION: An imaging apparatus includes an imaging lens, an imaging element, a detection unit, an image memory, a slope angle memory, and a decision unit. The imaging element images an object image formed on a light receiving plane by the imaging lens. The detection unit detects a slope angle of the image sensor in an optional direction on a plane perpendicular to the optical axis of the imaging lens. The image memory records an image of the object image imaged by the imaging element. The slope angle memory associates the slope angle detected by the detection unit with the image and memorizes it. The decision unit decides the quality of the image based on the slope angle. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an imaging apparatus that can capture an image without inclination.

  Conventionally, when a photographer holds a picture with a digital camera or the like, the photographed image may be tilted even though the photographer intends to keep the digital camera or the like horizontal. So far, various technologies have been developed to keep a digital camera or the like horizontal.

  Patent Document 1 discloses a technique for displaying an auxiliary line image indicating that an image is tilted together with a through image of a subject image on a display unit when a sensor that detects the tilt angle of the digital camera detects the tilt of the digital camera. is doing.

Patent Document 2 discloses a technique for processing a captured image and correcting the tilt when a sensor that detects the tilt angle of the digital camera detects the tilt of the digital camera.
JP 2008-28728 A JP 2004-104213 A

  However, in Patent Document 1, the photographer puts the auxiliary line of the auxiliary line image on the subject image of the through image so that the digital camera is in a horizontal state, but the unstable place or the auxiliary line image is difficult to see. Etc. were difficult.

  Further, in Patent Document 2, since a correction process is performed in which a captured image is rotated by an inclination angle and then trimmed, the peripheral portion of the image is cut off, resulting in an image different from the photographer's intention. was there.

  SUMMARY OF THE INVENTION In view of the above-described problems of the prior art, an object of the present invention is to provide a technique that can capture an image without inclination even when handheld shooting such as a digital camera is performed.

  An image pickup apparatus according to the present invention includes an image pickup lens, an image pickup element that picks up a subject image formed on a light receiving surface by the image pickup lens, and an inclination angle of the image pickup element with respect to an arbitrary direction on a plane orthogonal to the optical axis of the image pickup lens. A detection unit for detecting the image, an image storage unit for recording an image of the subject image captured by the image sensor, an inclination angle storage unit for storing the inclination angle detected by the detection unit in association with the image, and an inclination angle And a determination unit that determines whether the image is acceptable or not.

  In the present invention, the image storage unit records a plurality of images continuously captured by the image sensor.

  In this invention, an image memory | storage part memorize | stores the several image imaged with the image pick-up element in the predetermined time interval.

  In this invention, the determination unit further includes a selection unit that selects only one image from the plurality of images based on the quality determination, and the image storage unit stores only one image selected by the selection unit.

  In this invention, the image storage unit sorts and stores one image based on a predetermined threshold.

  In the present invention, the pass / fail determination is performed by determining the smallest angle among the tilt angles as the best.

  In this invention, the image storage unit sorts and stores images based on a predetermined threshold.

  In the present invention, the arbitrary direction is any direction of 0 degree, 90 degrees, 180 degrees, or 270 degrees with respect to the direction of gravity.

  According to the present invention, an image having no inclination can be captured even when handheld shooting such as a digital camera is performed.

<< One Embodiment >>
FIG. 1 is a configuration diagram of a digital camera 100 according to an embodiment of the present invention.

  The digital camera 100 includes an imaging lens 1, an imaging device 2, an A / D conversion unit 3, a buffer memory 4, a CPU 5, a tilt detection sensor 6, a card interface (card I / F) 7, a card memory 8, an operation member 9, and storage. The unit 10 includes a display unit 11 and an image processing unit 12. The buffer memory 4, the CPU 5, the tilt detection sensor 6, the card I / F 7, the operation member 9, the storage unit 10, the display unit 11, and the image processing unit 12 are connected via a bus 13 so that information can be transmitted. FIG. 1 shows only the main part of the digital camera 100. For example, in FIG. 1, a timing generator that emits timing pulses for imaging instructions to the image sensor 2 and the A / D conversion unit 3 in accordance with instructions from the CPU 5 is omitted.

  The imaging lens 1 is composed of a plurality of optical lenses, and forms a subject image on the light receiving surface of the imaging element 2.

  The imaging device 2 operates based on timing pulses generated by a timing generator (not shown) that receives a command from the CPU 5 and acquires a subject image formed by the imaging lens 1 provided in front. As the image sensor 2, a CCD or CMOS semiconductor image sensor or the like can be appropriately selected and used.

  The image signal output from the image sensor 2 is converted into a digital signal by the A / D converter 3. The converted digital image signal is temporarily recorded in a frame memory (not shown) and then recorded in the buffer memory 4. As the buffer memory 4, a nonvolatile memory or the like that is a semiconductor memory can be appropriately selected and used.

  When the power of the digital camera 100 is turned on by the user operating the power button on the operation member 9, the CPU 5 reads the control program stored in the storage unit 10 and initializes the digital camera 100. Thereafter, the CPU 5 outputs a subject imaging command to a timing generator (not shown) according to an instruction from the user via the operation member 9, causes the image processing unit 12 to perform image processing of the captured image, or the card memory. 8 and the display unit 11 are controlled. As the CPU 5, a CPU of a general computer can be used.

  The tilt detection sensor 6 detects an angle formed by the reference direction and the horizontal scanning direction or the vertical scanning direction of the image sensor 2 as a tilt angle of the digital camera 100 on a plane orthogonal to the optical axis of the imaging lens 1. . In the present embodiment, when the digital camera 100 is imaged in the normal position (the optical axis of the imaging lens 1 is horizontal and the lower surface of the digital camera 100 is held downward) as the reference direction, gravity is used. The direction. Further, when the digital camera 100 is rotated 90 degrees, 180 degrees, or 270 degrees around the optical axis of the imaging lens 1 from the normal position of the digital camera 100, 90 degrees, 180 degrees, or 270 degrees with respect to the direction of gravity. Each direction is a reference direction. The CPU 5 determines which of the four states of the digital camera 100 is based on the tilt angle detected by the tilt detection sensor 6 before shooting, and sets a reference direction. As the tilt detection sensor 6, a general acceleration sensor, an electronic gyro, or the like can be appropriately selected and used. Note that the tilt detection sensor 6 has detection accuracy that can detect the quality of an image based on the tilt angle, for example, the tilt angle can be detected in units of 1 degree or 5 degrees. The image quality determination based on the tilt angle will be described in detail later.

  A card memory 8 is detachably attached to the card I / F 7. The image recorded in the buffer memory 4 is subjected to image processing by the image processing unit 12 based on an instruction from the CPU 5 and then recorded in the card memory 8 as a file in the Exif format or the like.

  The operation member 9 outputs an operation signal corresponding to the content of the member operation by the user to the CPU 5. The operation member 9 includes, for example, a power button, a mode setting button such as a shooting mode, and a release button. The operation member 9 may be a touch panel button displayed on the display unit 11 described later.

  The storage unit 10 records image data captured by the digital camera 100 and stores a control program for the CPU 5 to control the digital camera 100. These programs and data stored in the storage unit 10 can be appropriately referred to by the CPU 5 via the bus 13. A storage device such as a general hard disk device or a magneto-optical disk device can be appropriately selected and used for the storage unit 10.

  The display unit 11 displays a through image, a captured image, a mode setting screen, or the like. A liquid crystal monitor or the like can be appropriately selected and used for the display unit 11.

  The image processing unit 12 is a digital front-end circuit that performs image processing such as contour enhancement processing and white balance correction based on an instruction for image processing of the CPU 5.

  Next, the digital camera 100 according to the present embodiment will be described with reference to the flowchart of FIG.

  When the user presses the power button on the operation member 9, the CPU 5 reads the control program stored in the storage unit 10 of the digital camera 100 and initializes the digital camera 100. The CPU 5 reads the tilt angle of the digital camera 100 detected by the tilt detection sensor 6 and sets a reference direction based on which of the four states of the digital camera 100 is. The CPU 5 stands by until an instruction for photographing the subject is issued from the user (step S10). In the following description, the user uses the mode setting button of the operation member 9 to set in advance a mode for taking a subject image by continuous shooting, and is detected by the tilt detection sensor 6 in the continuously shot images. It is assumed that an image with the smallest inclination angle is set to a mode for selecting and holding the best image. In the present embodiment, the reference direction is the direction of gravity. That is, a case where the digital camera 100 is imaged at the normal position will be described. The processing procedure is the same when imaging the digital camera 100 in another state.

  Step S10: The CPU 5 stands by until it accepts a subject imaging instruction from the user (NO side). When the user presses the release button of the operation member 9, the CPU 5 determines that an imaging instruction has been issued and proceeds to step S11 (YES side).

  Step S11: The CPU 5 causes the tilt detection sensor 6 to detect the tilt angle of the image sensor 2, and simultaneously issues an imaging command to a timing generator (not shown). A timing generator (not shown) emits a timing pulse to the image sensor 2 to cause the image sensor 2 to capture a subject image formed by the imaging lens 1. The CPU 5 causes the image sensor 2 to output the pixel value of each pixel as an analog signal of the subject image via a timing generator (not shown). The output analog signal is converted into a digital signal by the A / D converter 3 and recorded as image data in the buffer memory 4. At the same time, the CPU 5 records the tilt angle value detected by the tilt detection sensor 6 in the buffer memory 4 in association with the captured image data.

  Step S12: The CPU 5 determines whether or not to end the imaging by the continuous shooting depending on whether or not the release button of the operation member 9 is kept pressed. If the release button has not been pressed, the CPU 5 determines that the imaging is to end and proceeds to step S13 (YES side). On the other hand, when the release button is pressed, the CPU 5 proceeds to step S11 (NO side). The CPU 5 performs next imaging by continuous shooting and detection of the tilt angle, and records the image data and the value of the tilt angle in the buffer memory 4.

  Step S <b> 13: The CPU 5 reads from the buffer memory 4 the value of the inclination angle corresponding to each of the plurality of image data captured by the continuous shooting in steps S <b> 10 to S <b> 12. The CPU 5 performs pass / fail judgment that the image of the image data indicating the smallest of the inclination angles is an image captured in a state closest to the horizontal in the imaging at the normal position of the digital camera 100. The CPU 5 transfers the image data selected based on the pass / fail judgment to the image processing unit 12 via the bus 13. Note that the CPU 5 may delete the other plurality of image data that have not been selected and the value of the inclination angle.

  Step S14: The image processing unit 12 performs image processing such as white balance processing, Bayer interpolation processing, saturation enhancement, contour enhancement, and noise removal on the transferred image data. The image processing unit 12 transfers the image data to the buffer memory 4 and records it.

  Step S15: The CPU 5 records the image data processed in step S14 in the buffer memory 4 into a file such as an Exif format to which the value of the inclination angle corresponding to the image is added, and records it in the card memory 8 for a series of operations. Exit.

  As described above, in this embodiment, a plurality of images are captured by continuous shooting, and the tilt detection sensor 6 detects the tilt angle of the digital camera 100 at the time of capturing each image, and the image when the tilt angle is the smallest is obtained. In the hand-held imaging at the normal position of the digital camera 100, it is possible to obtain an image without an inclination by performing the pass / fail determination that the image is captured in the most horizontal state.

In addition, since the image with the smallest tilt angle value is selected from a plurality of images captured by continuous shooting of the image sensor 2, it is possible to capture images in a dark place or in an unstable situation such as a ship or a train. It is also easy to obtain an image captured in a horizontal state even in imaging or the like in situations where it is difficult to confirm a through image on the display unit 11 such as when imaging or the body must be bent or twisted. Can do.
<< Other Embodiments >>
A digital camera according to another embodiment of the present invention will be described using a digital camera 100 shown in FIG. 1 as a modification of the embodiment with reference to the flowchart of FIG.

  As in the case of the first embodiment, when the user presses the power button on the operation member 9, the CPU 5 reads the control program stored in the storage unit 10 of the digital camera 100 and initializes the digital camera 100. The CPU 5 reads the tilt angle of the digital camera 100 detected by the tilt detection sensor 6 and sets a reference direction based on which of the four states of the digital camera 100 is. The CPU 5 stands by until an instruction for photographing the subject is issued from the user (step S20). As in the case of the first embodiment, the user sets in advance a mode for capturing a subject image by continuous shooting using the mode setting button of the operation member 9, and the tilt detection sensor 6 among the continuously shot images. It is assumed that the mode in which the image having the smallest inclination angle detected by (1) is selected and held as the best image is set. Also in this embodiment, the reference direction is the gravity direction. That is, a case where the digital camera 100 is imaged at the normal position will be described. Further, the user inputs a predetermined inclination angle value α (± 5 degrees in the present embodiment), which is a threshold for distributing the captured image, via the operation member 9, and distributes it to the card memory 8. Two storage areas (for example, folders) are created.

  Step S20: The CPU 5 stands by until it accepts a subject imaging instruction from the user (NO side). When the release button of the operation member 9 is pressed by the user, the CPU 5 determines that an imaging instruction has been issued, and proceeds to step S21 (YES side).

  Step S21: The CPU 5 causes the tilt detection sensor 6 to detect the tilt angle of the image sensor 2 and issues an imaging command to a timing generator (not shown). A timing generator (not shown) emits a timing pulse to the image sensor 2 and images a subject image formed by the imaging lens 1. The CPU 5 causes the image sensor 2 to output the pixel value of each pixel as an analog signal of the subject image via a timing generator (not shown). The analog signal of the image is converted into a digital signal by the A / D converter 3 and recorded as image data in the buffer memory 4. At the same time, the CPU 5 records the value of the inclination angle detected by the inclination detection sensor 6 in the buffer memory 4 in association with the captured image data.

  Step S22: The CPU 5 determines whether or not to end the imaging by continuous shooting based on whether or not the release button of the operation member 9 is kept pressed. If the release button has not been pressed, the CPU 5 determines that the imaging is to end and proceeds to step S23 (YES side). On the other hand, when the release button is pressed, the CPU 5 proceeds to step S21 (NO side). The CPU 5 performs next imaging by continuous shooting and detection of the tilt angle, and records the image data and the value of the tilt angle in the buffer memory 4.

  Step S23: The CPU 5 reads from the buffer memory 4 the values of the tilt angles corresponding to the plurality of image data captured by the continuous shooting in steps S20 to S22. The CPU 5 performs pass / fail judgment that the image of the image data indicating the smallest of the inclination angles is an image captured in a state closest to the horizontal in the imaging at the normal position of the digital camera 100. The CPU 5 transfers the image data selected based on the pass / fail judgment to the image processing unit 12 via the bus 13. Note that the CPU 5 may delete the other plurality of image data that have not been selected and the value of the inclination angle.

  Step S24: The image processing unit 12 performs image processing such as white balance processing, Bayer interpolation processing, saturation enhancement, contour enhancement, and noise removal on the transferred image data. The image processing unit 12 transfers the image data to the buffer memory 4 and records it.

  Step S25: The CPU 5 determines whether or not the inclination angle of the image data processed in step S24 is smaller than a predetermined inclination angle value α input by the user, and distributes the images according to the determination. That is, when the inclination angle of the image is smaller than α, the CPU 5 proceeds to step S26 (YES side). On the other hand, when the inclination angle of the image is as large as α or more, the CPU 5 proceeds to step S27 (NO side).

  Step S <b> 26: The CPU 5 converts the image data processed in step S <b> 24 in the buffer memory 4 into a file such as an Exif format to which the inclination angle value corresponding to the image is added, and stores it in one storage area of the card memory 8. Record and finish a series of work.

  Step S27: The CPU 5 converts the image data processed in step S24 in the buffer memory 4 into a file such as an Exif format to which the value of the inclination angle corresponding to the image is added, and stores it in the other storage area of the card memory 8. Record and finish a series of work.

  As described above, in this embodiment, a plurality of images are captured by continuous shooting, and the tilt detection sensor 6 detects the tilt angle of the digital camera 100 at the time of capturing each image, and the image when the tilt angle is the smallest is obtained. In the hand-held imaging at the normal position of the digital camera 100, it is possible to obtain an image without an inclination by performing the pass / fail determination that the image is captured in the most horizontal state.

  In addition, since the image with the smallest tilt angle value is selected from a plurality of images captured by continuous shooting of the image sensor 2, it is possible to capture images in a dark place or in an unstable situation such as a ship or a train. It is also easy to obtain an image captured in a horizontal state even in imaging or the like in situations where it is difficult to confirm a through image on the display unit 11 such as when imaging or the body must be bent or twisted. Can do.

Further, since the captured images are sorted and recorded in accordance with a predetermined inclination angle value α set by the user, it is easy to process and organize after shooting.
≪Supplementary items for the embodiment≫
In one embodiment and another embodiment, while image capturing by continuous shooting is being performed, the captured image data and the value of the tilt angle are all recorded in the buffer memory 4, but the present invention is not limited to this. For example, as shown in the flowchart of FIG. 4 in which steps S11a and S11b are added to FIG. 2 and the flowchart of FIG. 5 in which steps S21a and S11b are added to FIG. The tilt angle of the image that has been recorded is compared with the tilt angle of the image data recorded in the buffer memory 4, image data having a smaller tilt angle is selected, and the image data and the tilt angle value are recorded. You may do it. Then, the image data and the value of the tilt angle recorded in the buffer memory 4 at the time when imaging by continuous shooting is completed should be selected in step S13 or step S23. By doing so, it is not necessary to secure an area for recording unnecessary image data in the buffer memory 4, and the circuit scale of the digital camera 100 can be reduced.

  In one embodiment and other embodiments, one image is selected from a plurality of images captured by continuous shooting, but the present invention is not limited to this. For example, the image with the smallest inclination angle may be selected from a plurality of images captured in a single shot during a certain time interval (for example, 1 minute or 5 minutes).

  In one embodiment and other embodiments, the quality of the image is determined based only on the value of the inclination angle. However, it is combined with other conditions such as obtaining the blurring state of the image from the compression ratio of the image. Therefore, it is preferable to perform a more accurate image quality determination.

  In one embodiment and other embodiments, when the digital camera 100 is fixed to a tripod or the like, the variation in the value of the inclination angle detected by the inclination detection sensor 6 is reduced. Therefore, if the variation in the value of the inclination angle is equal to or less than the predetermined value, the CPU 5 determines that the digital camera 100 is fixed to a tripod or the like, and cancels the quality determination mode based on the inclination angle. good. On the other hand, even when the digital camera 100 is fixed to a tripod or the like, in the case of an unstable situation such as a ship, variation in the value of the tilt angle detected by the tilt detection sensor 6 becomes large. Therefore, when the variation in the value of the inclination angle becomes equal to or greater than a predetermined value, the CPU 5 may forcibly set the CPU even if the quality determination mode based on the inclination angle is cancelled.

  Note that, in one embodiment and another embodiment, the digital camera 100 is imaged in a state where the digital camera 100 is rotated at 90 degrees or the like around the normal position or the optical axis of the imaging lens 1, but the present invention is not limited to this. . The digital camera 100 can be tilted and imaged in a state other than the four states such as the normal position. In this case, it is preferable that the CPU 5 determines which of the four states such as the normal position is close based on the value of the inclination angle by the inclination detection sensor 6 and sets a reference direction. In particular, in another embodiment, when capturing an image in an arbitrary state, the CPU 5 creates a new storage area in the card memory 8 or the like, and sorts and records the captured image in the new storage area. Is preferred.

  In one embodiment and other embodiments, the reference direction is any direction that is 0 degree, 90 degrees, 180 degrees, or 270 degrees with respect to the direction of gravity. However, the present invention is not limited to this. Not. For example, if a gyro or the like is used as the tilt detection sensor 6, the direction referred to by the gyro or the like may be used as a reference direction, or a direction determined by GPS (Global Positioning System) or the like may be used as a reference direction.

  In other embodiments, the captured images are sorted and recorded in one of the two storage areas of the card memory 8 based on the magnitude of the predetermined inclination angle value α. It is not limited. For example, two storage areas may be created in the storage unit 10 and images may be sorted and recorded, or two card I / Fs 7 and a card memory 8 may be used to store an image using one card memory 8 as a storage area. It may be recorded separately.

  In another embodiment, the captured images are sorted and recorded according to one predetermined inclination angle value α. However, the present invention is not limited to this, and two or more predetermined inclination angle values are used. It is also possible to distribute and record in two or more storage areas.

  In other embodiments, in step S23, only the image data having the smallest inclination angle and the value of the inclination angle are selected and recorded from among a plurality of images taken by continuous shooting. However, the present invention is not limited to this. Each of a plurality of images captured by continuous shooting may be sorted and recorded according to the magnitude of a predetermined inclination angle value α.

  In another embodiment, the predetermined inclination angle value α is input by the user using the operation member 9, but the present invention is not limited to this. For example, when the user selects a shooting mode such as landscape, portrait, and sports through the operation of the mode selection button of the operation member 9, a predetermined inclination angle value α is set according to the set shooting mode. May be set. That is, for example, when the landscape mode is set, the predetermined inclination angle value α is set to ± 5 degrees, and when the portrait mode is set, the predetermined inclination angle value α is set to ± 10 degrees. Alternatively, when the sports shooting mode is set, the value α of the predetermined inclination angle is not particularly set, and the quality determination according to the inclination angle may be canceled.

1 is a block diagram showing a configuration of a digital camera 100 according to the present invention. The flowchart of the process in the digital camera 100 in one embodiment. Flowchart of processing in digital camera 100 according to another embodiment Another flowchart of processing in digital camera 100 in one embodiment Another flowchart of processing in the digital camera 100 according to another embodiment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image pickup lens, 2 Image pick-up element, 3 A / D conversion part, 4 Buffer memory, 5 CPU, 6 Inclination detection sensor, 7 Card I / F, 8 card memory, 9 Operation member, 10 Storage part, 11 Display part, 12 Image processing unit, 13 buses, 100 digital camera

Claims (8)

An imaging lens;
An image sensor for imaging a subject image formed on a light receiving surface by the imaging lens;
A detection unit that detects an inclination angle of the imaging element with respect to an arbitrary direction on a plane orthogonal to the optical axis of the imaging lens;
An image storage unit for recording an image of the subject image captured by the image sensor;
An inclination angle storage unit for storing the inclination angle detected by the detection unit in association with the image;
An image pickup apparatus comprising: a determination unit configured to determine quality of the image based on the tilt angle. The imaging device according to claim 1,
The image storage unit records a plurality of images continuously captured by the image sensor. The imaging device according to claim 1,
The image storage unit stores a plurality of images captured by the image sensor at predetermined time intervals. In the imaging device according to claim 2 or 3,
The determination unit
A selection unit that selects only one of the plurality of images based on the quality determination;
The image storage unit stores only the one image selected by the selection unit. The imaging apparatus according to claim 4,
The imaging apparatus according to claim 1, wherein the image storage unit sorts and stores the one image based on a predetermined threshold. The imaging device according to any one of claims 1 to 5,
In the image quality determination apparatus, the pass / fail determination determines that the smallest angle among the tilt angles is the best. The imaging apparatus according to any one of claims 1 to 3,
The image storage unit distributes and stores the image based on a predetermined threshold value, and stores the image. The imaging device according to any one of claims 1 to 7,
2. The imaging apparatus according to claim 1, wherein the arbitrary direction is any one of 0 degree, 90 degrees, 180 degrees, and 270 degrees with respect to the direction of gravity.

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