JP5094070B2 - Imaging apparatus, imaging method, program, and storage medium - Google Patents

Description

  The present invention relates to an imaging apparatus, an imaging method, a program, and a storage medium, and in particular, a digital device including an optical member such as a focus lens for focusing on a main subject from a plurality of subjects in a shooting area. The present invention relates to an imaging apparatus such as a still camera and a digital video camera, an imaging method, a program, and a storage medium.

  Conventionally, there are digital still cameras, digital video cameras (DVC), and the like that include an image sensor such as a CCD that acquires a still image of a subject. Such an imaging apparatus has a moving image shooting function for recording a plurality of still images (frames) acquired at a predetermined frame rate as a moving image on a predetermined recording medium.

  In addition, in an imaging apparatus, at the time of moving image shooting or still image shooting, an optical member such as a focus lens is used to focus on an arbitrary subject (hereinafter referred to as “main subject”), for example, a person in a shooting region. It is possible to perform the focusing process. Accordingly, it is possible to obtain a clear image that is free from out-of-focus (out-of-focus) of the main subject.

As an image pickup apparatus, an image signal recording apparatus has been proposed in which a plurality of image pickup elements are arranged at different positions on the optical axis (see, for example, Patent Document 1). In such an image signal recording apparatus, by using a plurality of image pickup devices, a plurality of main subjects, for example, a person and a background, which differ greatly in distance from the image signal recording apparatus to the subject (hereinafter referred to as “subject distance”), respectively. It is possible to focus on. Thereby, it is possible to simultaneously acquire an image focused on the person and an image focused on the background. Furthermore, by combining these images, it is possible to acquire a single clear image in which both the person and the background are focused.
Japanese Patent Laid-Open No. 10-257369 (paragraph 0025)

  However, the conventional imaging apparatus as described above cannot focus on a subject (hereinafter referred to as “sub-subject”) having a subject distance different from that of the main subject at the time of shooting regardless of the number of imaging elements. As a result, the conventional imaging apparatus cannot acquire an image obtained by clearly capturing the sub-subject.

  Note that in the image signal recording apparatus described in Patent Document 1 described above, a focus on a main subject close to the sub-subject among a plurality of main subjects is acquired in order to obtain an image obtained by clearly capturing a sub-subject different from the main subject after the end of shooting. You can select images that match. However, since the sub-subject was not completely focused and photographed, it cannot be said that the sub-subject is clear in the selected image.

  Accordingly, there is a need for an imaging device that can acquire an image in which an arbitrary subject is clearly captured regardless of the timing of imaging.

  In addition, during moving image shooting, even if the main subject is focused at the start of shooting, if the subject distance (position) of the main subject changes during the shooting, the focus on the main subject will not follow. As a result, when the acquired moving image is reproduced, the image of the main subject gradually becomes out of focus. Thus, it is difficult for an imaging apparatus having a conventional moving image shooting function to acquire a moving image in which a relatively moving subject is clearly captured.

  Secondly, in the image signal recording apparatus described in Patent Document 1, by arranging a plurality of image pickup elements, the cost of the image pickup apparatus increases by the amount of expensive image pickup elements and accompanying components, and the apparatus is large. Turn into. This has to be contrary to the trend of low cost and miniaturization in recent imaging devices.

  A first object of the present invention is to provide an imaging device, an imaging method, a program, and a storage medium that can acquire an image in which a desired subject is clearly captured.

  A second object of the present invention is to provide an imaging device, an imaging method, a program, and a storage medium capable of acquiring a clear image at low cost without causing an increase in the size of the imaging device.

In order to achieve the above object, an imaging apparatus according to the present invention includes an image signal output unit that outputs an image signal according to light from a subject, a focus lens control unit that moves a focus lens, and the image signal output unit. storage means for storing an image based on the image signal, the focus lens control unit by the focus lens predetermined in focus at different distances by moving in a range of a plurality of images said storage means to get a a storage operation that stores Just repeat periodically, the combined focus from one period of the plurality of images corresponding stored in the image or the second object was in focus to the first object based on the user's selection acquisition means for acquiring an image as a frame, constructed as a moving image by arranging the obtained image as the frame A moving image constructing unit that stores the moving image in the storage unit, and the first subject that is not selected by the user after the moving image constructed by the moving image constructing unit is stored in the storage unit Acquired by the storage operation repeated periodically so that the moving image construction means can construct an image focused on the image or an image focused on the second subject as a moving image. Still image storage means for storing a plurality of images in the storage means as a still image aggregate for each period .

In order to achieve the above object, an imaging method of the present invention includes an image signal output step for outputting an image signal according to light from a subject, a focus lens control step for moving a focus lens, and the image signal output step. And a storage step of storing an image based on the output image signal in a storage unit . The program causes a computer to execute an imaging method for acquiring an image, wherein the imaging method is performed by the focus lens control step. the repeatedly storing operation for storing periodically the predetermined said memory means acquires a plurality of images in focus at different distances by moving the range, one of the plurality of images the storage from cycle to the image or the second object was in focus to the first object based on the user's selection Image and acquiring one frame of the combined Okasu, constructed as a moving image by arranging the acquired image as one frame, and the moving image construction step of storing the moving image in the storage means, the moving After the moving image constructed by the image construction step is stored in the storage means, an image focused on the first subject or an image focused on the second subject not selected by the user A still image storage step of storing a plurality of images acquired by the periodically repeated storage operation in the storage unit as a still image aggregate for each period so that the image can be constructed as a moving image; , characterized by having a.

In order to achieve the above object, the program of the present invention outputs an image signal output step for outputting an image signal in accordance with light from a subject, a focus lens control step for moving a focus lens, and an output from the image signal output step. And a storage step of storing an image based on the image signal stored in a storage unit, the program for causing a computer to execute an imaging method for acquiring an image, wherein the imaging method includes: a storage operation to store in the memory means to repeatedly periodically a plurality of images in focus at different distances by moving in a predetermined range acquired, one cycle of the plurality of images the storage the first image or the combined focus on the subjects second object based know the user's selection An acquisition step of acquiring an image in focus as a frame, constructed as a moving image by arranging the acquired image as one frame, and the moving image construction step of storing the moving image in the storage means, the moving After the moving image constructed by the image construction step is stored in the storage means, an image focused on the first subject or an image focused on the second subject not selected by the user A still image storage step of storing a plurality of images acquired by the periodically repeated storage operation in the storage unit as a still image aggregate for each period so that the image can be constructed as a moving image; , characterized by having a.

  In order to achieve the above object, a storage medium of the present invention stores the above program.

  According to the present invention, a focus scan for acquiring a still image aggregate is executed while moving an optical member for focusing on a desired subject between the first position and the second position. By one focus scan, a still image aggregate composed of a plurality of still images in which the main subject and at least one sub-subject are in focus is acquired. This makes it possible to acquire an image in which a desired subject is clearly captured from the still image aggregate. In addition, regardless of the number of imaging elements constituting the imaging unit that acquires a still image, that is, even if the number of imaging elements is small, an image in which a desired subject is clearly captured can be acquired. The cost can be reduced without increasing the size.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 and FIG. 2 are perspective views schematically showing the appearance of the front side and the back side of the digital still camera as the imaging apparatus according to the first embodiment of the present invention.

  1 and 2, the digital still camera 100 has a housing 10. As shown in FIG. 1, on the front surface of the housing 10, a lens barrel 11 containing an imaging unit 2 in FIG. 3 to be described later, and an optical finder 12 composed of an objective lens and an eyepiece are disposed. . A release button 13 and a strobe 14 are disposed on the upper surface of the housing 10. The lens barrel 11 and the strobe 14 are configured to protrude from the surface of the housing 10. As shown in FIG. 2, a power switch 15, a display 16, a zoom button 18, and three operation buttons 19 a, 19 b, 19 c for performing a predetermined operation on the display 16 are provided on the rear surface of the housing 10. Is arranged. The display 16 also functions as an electronic viewfinder for determining the angle of view.

  The digital still camera 100 has a still image shooting mode for acquiring a still image of a subject and a moving image shooting mode for acquiring a moving image of the subject, and either one is operated by the user operating the operation buttons 19a to 19c. The shooting mode can be selected.

  FIG. 3 is a block diagram schematically showing an internal configuration of the digital still camera 100 of FIGS. 1 and 2.

  In FIG. 3, a digital still camera 100 includes a camera microcomputer 1, an imaging unit 2, a contrast comparison unit 3, a contrast measurement unit 4, a light emitting unit 5, an image display unit 6, a recording unit 7, and data processing. Unit 8 and subject instruction unit 9. The camera microcomputer 1 is connected to the units 2 to 9, and the units 2 to 9 perform, for example, the following operations based on the control of the camera microcomputer 1. The imaging unit 2 includes a photographic lens group described later and one imaging element. The imaging unit 2 and the lens barrel 11 constitute a photographing optical system. The photographing lens group includes a focus lens for focusing on a main subject, which will be described later, and a zoom lens for performing enlargement / reduction of the main subject in accordance with the operation of the zoom button 18.

  The imaging unit 2 moves at least one lens of the lens barrel 11 and the photographing lens group, for example, a focus lens (hereinafter referred to as “lens barrel driving”). When the lens barrel is driven, the focus lens is moved to focus on the main subject selected from a plurality of subjects in the shooting area of the digital still camera 100. The light emitting unit 5 drives the strobe 14. The image display unit 6 displays a predetermined image on the display 16. The recording unit 7 performs image capturing in which an image acquired by one image sensor included in the imaging unit 2 is recorded as image data in the memory of the recording unit 7. The data processing unit 8 can synthesize a plurality of image data. The subject instruction unit 9 inputs information about a subject to be focused (hereinafter referred to as “main subject”) to the camera microcomputer 1 among a plurality of subjects in the shooting area. The main subject is determined by the user setting a partial area (hereinafter referred to as “selected area”) from a shooting area corresponding to the display range of the electronic viewfinder or the optical viewfinder, for example. Instead of setting the selection area, a predetermined focal position selected within a range in which the focal position of the focus lens can be changed may be set. Accordingly, the camera microcomputer 1 can recognize (specify) the main subject, and drives the imaging unit 2 to focus on the specified main subject.

  The selection area and the focus position, that is, the selection of the main subject, is preferably performed on the display 16 while the user operates the operation buttons 19a to 19c. However, the present invention is not limited to this. For example, when the display 16 is a touch panel type, the user may operate the touch panel. Further, when a cross key, a jog dial or the like is provided instead of the operation buttons 19a to 19c, the user may move the cursor on the display 16 using these buttons. In setting the selection area, it is preferable to use a rectangular window whose size can be changed to a size that can surround the main subject, but the present invention is not limited to this.

  Further, the camera microcomputer 1 specifies a predetermined person based on the skin color occupancy ratio in the captured image, the face color of the person registered in advance, or the color of clothes by using a known recognition unit, for example. You can also Furthermore, the camera microcomputer 1 can also track a specified main subject, for example, a predetermined person within the shooting region, whereby the digital still camera 100 continuously acquires an image in which the main subject is in focus. can do.

  Hereinafter, the operation of the digital still camera 100 in the moving image shooting mode will be described.

  The digital still camera 100 is activated when the user operates the power switch 15. After the activation, the camera microcomputer 1 makes the digital still camera 100 ready for photographing by causing the lens barrel 11 and the strobe 14 to protrude from the surface of the housing 10. The user determines the angle of view while viewing the image of the subject displayed on the display 16. At this time, the zoom lens 18 is driven by depressing the zoom button 18 as necessary to change the focal position of the photographing lens group. Thereafter, when the user depresses the release button 13, the digital still camera 100 starts driving the lens barrel and starts shooting a moving image of the subject.

  FIG. 4 is a flowchart of image data processing executed by the digital still camera 100 of FIG. This process is executed according to the control of the camera microcomputer 1 of the digital still camera 100.

  In FIG. 4, when moving image shooting is started in response to the user pressing the release button 13, first, in step S <b> 11, the camera microcomputer 1 captures a large number of still images (frames) constituting the moving image of the subject. Then, the image capturing process described in detail with reference to FIG. 5 is executed.

  FIG. 5 is a flowchart showing details of the image capturing process executed in step S11 of FIG.

  In this image capturing process, the imaging unit 2 performs focus scanning that captures a subject at a plurality of intermittent timings while changing the focal position of the focus lens. By this focus scanning, a still image aggregate of a subject composed of a plurality of still images is acquired as image data. At this time, the recording unit 7 sequentially records image data corresponding to each still image acquired by the imaging unit 2 in the memory of the recording unit 7.

  FIG. 6 is a diagram for explaining the focus scan executed in the process of FIG.

  FIG. 6 shows the relationship between the time t of a plurality of focus scans executed continuously and the subject distance L. Here, the subject distance L indicates the distance between the positions of the digital still camera 100 and the main subject, that is, the distance between the digital still camera 100 and the focus position of the focus lens.

  In multiple focus scans, the focal position of the focus lens varies periodically from the closest focus distance (hereinafter referred to as “closest”) to the infinity focus distance (hereinafter referred to as “infinity”). I am letting. It should be noted that the subject distance L is the shortest at the closest distance, and the subject distance L is the longest at infinity. Since the time required for one focus scan corresponds to a half cycle of fluctuation of the value of the subject distance L as shown in FIG. 6, the first focus scan is performed when the subject distance L is close or infinite. Preferably it begins.

  In addition, each focus / scan is executed so as to be synchronized with a frame rate, for example, 30 fps (frame per second) when a moving image of a subject is captured in the moving image mode. Therefore, one focus scan is executed at a very high speed because it is executed until imaging of each frame is completed.

  In FIG. 5, first, in step S111, it is determined whether or not the focal position is at infinity (infinity focus distance). As a result of the determination, if the focal position is not infinite, the process proceeds to step S114. If the focal position is infinite, in steps S112 to S113, a focus scan corresponding to the half cycle in FIG. 6 is executed once. .

  Specifically, the imaging unit 2 starts high-speed lens barrel driving so that the focal position changes from the infinity side to the close side. As a result, the focal position corresponds to one of a plurality of subject distances L1 to L20 as shown in FIG. Note that the subject distances L1 to L20 are set in advance to stop the lens barrel drive, as will be described later with reference to FIG. As a result, it is determined whether or not each member constituting the photographing optical system has a predetermined optical arrangement (step S112). When each member has a predetermined optical arrangement, the lens barrel drive is stopped for a short time, and image capture is performed by taking a still image (step S113). After the image capturing is completed, the lens barrel driving is started again. The processes in steps S112 to S113 are repeatedly executed, for example, 20 times until the focal position reaches the closest position (the closest focus distance) as a result of the lens barrel drive (YES in step S114). The focus scan ends.

  Therefore, in one focus scan, as shown in FIG. 7, one still image aggregate 700 composed of 20 still images captured at the focal positions corresponding to the subject distances L20 to L1 is acquired. Is done. Here, since one focus scan is synchronized with the frame rate, one image capture (step S113) is performed at a speed 20 times the frame rate, that is, 600 fps.

  Subsequently, it is determined whether or not the release button 13 has been pressed (step S115). When the release button 13 has been pressed, in steps S116 to S117, the focus corresponding to the half cycle of the change in the value of the subject distance L is determined. • Perform a scan once. Specifically, the same focus and scan as the processing in steps S112 to S113 is executed.

  Here, as shown in FIG. 6, in order to smoothly execute the two focus scans that are successively executed, in the lens barrel drive in the focus scans of steps S116 to S117, the focus position is changed from the closest side. Change to infinity side. As a result, a still image aggregate 700 composed of 20 still images captured at the focal positions corresponding to the subject distances L1 to L20 is acquired. If the focus position reaches infinity as a result of the lens barrel drive (YES in step S118), the focus scanning in steps S116 to S117 is terminated, and the process proceeds to step S119.

  In a succeeding step S119, it is determined whether or not the release button 13 is pressed. If the release button 13 is not pressed as a result of the determination, the process returns to step S112 to repeatedly execute the above-described two continuous focus scans. On the other hand, when the release button 13 is pressed, this processing is performed. Exit. Thereafter, the process returns to step S12 in FIG.

  According to the processing of FIG. 5, a plurality of still image aggregates 700 can be acquired by a plurality of focus scans. Each still image aggregate 700 includes at least one still image (hereinafter referred to as “frame”) 800 to be extracted as one frame of a moving image in step S13 described later in FIG. The plurality of still image aggregates 700 acquired in this way are stored in the memory of the recording unit 7. If necessary, moving image data may be compressed in order to reduce the data size.

  As shown in FIG. 6, when the subject distance La corresponding to a preset main subject is set as the subject distance L, a frame corresponding to the subject distance La from a plurality of still image aggregates 700. Is extracted. A moving image is constructed from the plurality of frames thus extracted, and the moving image is stored in the memory of the recording unit 7 as moving image data.

  In the process of FIG. 5, the processes of step S111 and step S119 may be omitted. Further, in the processing of FIG. 5, this processing is configured to end when the release button 13 is pressed in steps S115 and S119, but instead of this, moving image shooting is performed while the release button 13 is pressed. The moving image shooting may be stopped when the release button 13 is released.

  FIG. 8 is a diagram used for explaining the subject distance L set in order to stop the lens barrel drive in steps S112 and S116 of FIG.

  In FIG. 8, the subject distance L10 'indicates the rear depth of field of the subject distance L10 in FIG. 7, and the subject distance L9' indicates the rear depth of field of the subject distance L9. It should be noted that the depth of field at each subject distance L is that there is practically no out-of-focus in the image of other subjects positioned forward and backward on the optical axis of the subject in focus (focused). This represents the range that can be considered, and is represented by the sum of the front depth of field and the rear depth of field. Further, the front depth of field and the rear depth of field are determined by using the diameter of an allowable confusion circle (allowable confusion circle diameter) set according to the image sensor used in the imaging unit 2. For this determination, a numerical value indicating the optical performance of the photographing optical system, for example, a focal length value may be used in addition to the allowable circle of confusion.

  Further, as shown in FIG. 8, the subject distance L10 is set so that the front depth of field coincides with the subject distance L9 'indicating the rear depth of field of the subject distance L9. Similarly, the rear depth of field L10 'of the subject distance L10 is set to coincide with the subject distance L11' indicating the front depth of field of the subject distance L11. Thereby, the depth of field at the subject distance L10 is continuous with the depth of field at the subject distances L9 and L11. Therefore, when shooting is performed at the subject distance L10, the subject located between the rear depth of field at the subject distance L9 and the forward depth of field at the subject distance L11 does not occur.

  As described above with reference to FIG. 8, the subject distances L1 to L20 are substantially equally spaced (incremental intervals) so that the depth of field of each subject distance L is continuous from the closest focus position to infinity. ) Is set as the value of the subject distance L. As a result, in each focus / scan executed in the processing of FIG. 5, moving images of a subject covering substantially all the subject distances L can be obtained simply by capturing an image at a focal position corresponding to the subject distances L1 to L20. It can be performed.

  Returning to the processing of FIG. 4, in step S12, the user selects a desired subject, for example, a subject (sub-subject) that is not in focus. This selection is preferably performed while reproducing on the display 16 a moving image (a plurality of still images corresponding to the black circles shown in FIG. 6) corresponding to the subject distance La acquired in step S11. Here, since the selected sub-subject is located at a subject distance L different from the subject distance La, for example, the subject distance Lb in FIG. 6, it is not in focus. Note that a plurality of still image aggregates 700 may be continuously reproduced instead of the moving image corresponding to the subject distance La.

  Therefore, the subject designating unit 9 uses, for example, the value of the subject distance Lb and area information (focused region information) as the information about the sub-subject in order to perform focusing processing for focusing on the sub-subject. Input to the microcomputer 1. As a result, the setting of the subject distance L is changed from the subject distance La to the subject distance Lb.

  In subsequent step S13, a frame 800 corresponding to the subject distance Lb is extracted from each of the plurality of still image aggregates 700. Specifically, first, the contrast measurement unit 4 includes the sub-subject and the vicinity thereof in each still image area constituting the still image aggregate 700 based on the focus area information selected in step S13. Specify the area (selected area). Next, the contrast measurement unit 4 in FIG. 3 measures the contrast value of a characteristic pixel in the selected area, for example, a pixel corresponding to a person's skin color. Note that the contrast value is higher for a focused pixel.

  FIG. 9 is a diagram illustrating an example of the measurement result of the contrast value by the contrast measurement unit 4.

  In the example illustrated in FIG. 9, the contrast value corresponding to the subject distance L10 among the subject distances L1 to L20 is the maximum for the predetermined pixel measured by the contrast measurement unit 4. In this way, the contrast comparison unit 3 extracts a still image having the maximum contrast value from the still image aggregate 700 as a frame 800. Therefore, in the example shown in FIG. 9, the subject distance L10 corresponds to the subject distance Lb. Note that although the frame 800 having the maximum contrast value is extracted, the frame 800 having the maximum data size or the compressed data size may be extracted.

  At this time, it is preferable to delete the still image that has not been extracted from the memory of the recording unit 7 so as to increase the storable capacity of the memory. Note that, instead of extracting, a copy of the corresponding still image may be created, so that the still image aggregate 700 can be reliably stored.

  As described above, the plurality of frames 800 extracted from the number of still image aggregates 700 corresponding to the number of frames is arranged in time series by the recording unit 7 and recorded in the memory of the recording unit 7 as new moving images. (Step S16). Specifically, as shown in FIG. 10, first, a plurality of frames 800a, 800b, 800c,..., 800n are extracted from a plurality of still image aggregates 700a, 700b, 700c,. Subsequently, these frames 800a to 800n are arranged in chronological order, and a new moving image 1000 is constructed. The moving image 1000 is stored in the memory of the recording unit 7 as moving image data. Thereafter, the digital still camera 100 enters a shooting standby state, and ends this processing.

  4 and 5, the still image aggregate 700 is acquired by performing still image shooting at a high focus position corresponding to a plurality of subject distances L during one focus scan (step S11). And FIG. 5). Therefore, the still image aggregate 700 includes a still image focused on the main subject and a still image focused on at least one sub-subject. As a result, an image in which a desired subject (main subject or sub-subject) is clearly captured can be reliably acquired.

  Further, according to this process, after capturing an image, the user can completely focus on a desired subject within the range of the subject depth in order to extract the frame 800 from the still image aggregate 700 (step S13). It is. This eliminates the need for the user to focus on a desired subject at the start of shooting. Therefore, it is possible to reliably solve the problem of the prior art that the desired subject is out of focus as a result of the failure to select the subject to be focused, and thus the concept of out-of-focus occurring in the desired subject can be eliminated. .

  Further, the digital still camera 100 is configured to be able to execute a focus scan for performing high-speed shooting while changing the focus position of the focus lens, and a still image aggregate 700 including an image in which a desired subject is clearly captured is provided. Can be acquired. As a result, for example, it is not necessary to provide another expensive image pickup device and its accompanying parts in the image pickup unit 2, thereby suppressing an increase in cost of the digital still camera 100 and preventing an increase in size thereof. be able to.

  Further, since only the frame 800 is extracted from the still image aggregate 700 in order to construct a new moving image 1000 (step S13), by changing the frame 800 to be extracted, another new moving image can be obtained. Can be easily created. As a result, the editability of image data by the user can be improved. For example, even when the subject distance indicating the relative position between the main subject and the digital still camera 100 changes every moment, moving image data that easily follows the focus on the main subject is easily created. be able to.

  In the above embodiment, the focus scan is applied when the moving image shooting mode is set. However, the focus scanning may be applied when the still image shooting mode is set, that is, when a still image of the subject is shot. In this case, after the shooting is completed, a still image in which the desired subject is clearly captured can be surely acquired by extracting or selecting an image in which the desired subject is in focus from the still image aggregate 700. be able to. Therefore, it is possible to reliably solve the problem of the prior art that the desired subject is out of focus as a result of the user missing the shooting timing, and thus the concept of out-of-focus occurring in the desired subject can be eliminated.

  In the present embodiment, the number of frames (number of frames) extracted for moving images from the still image aggregate 1000 can be changed or the frames can be edited. These will be described as first and second modifications.

  FIG. 11 is a diagram showing a moving image acquired by the first modification of the present embodiment.

  A moving image 1100 constructed from a plurality of still images shown in FIG. 11 is obtained by increasing the number of frames of the moving image 1000 in FIG. Specifically, frames 810a, 810b, 810c,..., 810n are further extracted from the still image aggregates 700a to 700n. That is, two frames are extracted from each still image aggregate. In this case, the two frames to be extracted and the value of the subject distance L are determined, for example, by the user selecting two subjects, for example, a person and a background on the display 16. Here, three or more frames may be extracted from each still image aggregate.

  Further, the number of frames of the moving image 1100 is twice the number of frames of the moving image 1000 in FIG. Therefore, when the moving image 1100 is played back at the same playback speed as that of the moving image 1000, the still image focused on the person and the still image focused on the background are alternately played back in a short time, that is, at high speed. Is done. As a result, it is possible to acquire a moving image that is visually recognized as if both of the subjects selected by the user are in focus.

  It is also possible to delete unnecessary frames from the moving image 1100, thereby reducing the memory capacity of the recording unit 7 necessary for storing the moving image 1100.

  FIG. 12 is a diagram showing a moving image acquired by the second modification of the present embodiment.

  A moving image 1200 constructed from a plurality of still images shown in FIG. 12 is obtained by extracting frames 800a to 800n and 810a to 810n from still image aggregates 700a to 700n. The moving image 1200 is different from the moving image 1100 in that frames 800a to 800n and 810a to 810n are combined by the data processing unit 8 to form combined frames 820a, 820b, 820c,.

  FIG. 13 is a flowchart of image data processing executed for obtaining the moving image 1200 of FIG. Note that this processing is largely the same as the processing in FIG.

  In FIG. 13, the processes of steps S21, S22, S23, and S26 are the same as the processes of steps S11, S12, S13, and S16 of FIG.

  In step S24, the data processing unit 8 synthesizes two frames extracted from each of the still image aggregates 700a to 700n. In a succeeding step S25, it is determined whether or not the synthesis of the frames extracted from all the still image aggregates has been completed. If the result of determination in step S25 is not complete, the process returns to step S22, and the processes in steps S22 to S24 are repeated. In step S22, another sub-subject may be further selected.

  When frame composition is completed (YES in step S25), the newly constructed moving image 1200 is stored as moving image data in step S26. Then, this process ends.

  According to the process of FIG. 13, two frames extracted from one still image aggregate are combined to construct a combined frame. The moving image 1200 (FIG. 12) constructed from the composite frames 820a to 820n has the same number of frames as the moving image 1000 of FIG. 10, and is half the number of frames of the moving image 1100 of FIG. is there. Therefore, the memory capacity of the recording unit 7 necessary for storing the moving image 1200 can be reduced without deleting a frame from the moving image 1100 in FIG.

  Also, when the moving image 1200 is played back at the same playback speed as the moving image 1100, unlike the moving image 1100, a still image focused on a person and a still image focused on a background are alternately played back. There is nothing. As a result, it is possible to obtain a smooth moving image that is less discomfort during reproduction than the moving image 1100.

  In the second modified example, two frames extracted from one still image aggregate are synthesized. In this case, it is preferable that the plurality of frames to be synthesized are in chronological order. The order is not limited to time series. For example, frames extracted from a plurality of still image aggregates and captured at different focal positions (values of subject distance L), specifically, a frame 800b in FIG. And 810c may be synthesized.

  In the first and second modifications, the moving images 1100 and 1200 can be easily constructed by storing the frames 800a to 800n and 810a to 810n in the memory of the recording unit 7. it can.

  The second embodiment of the present invention will be described below.

  The digital still camera as the imaging apparatus according to the present embodiment is different only in the configuration of the imaging optical system (imaging unit 2) of the imaging apparatus (digital still camera in FIG. 1) according to the first embodiment. Since other configurations and components are the same, the description thereof is omitted. Specifically, the digital still camera according to the present embodiment is different from the imaging unit 2 according to the first embodiment in that the imaging unit includes a plurality of imaging elements.

  FIG. 14 is a block diagram schematically showing a configuration of a photographing optical system of a digital still camera as an image pickup apparatus according to the second embodiment.

  As shown in FIG. 14, the imaging unit 2 'of the digital still camera according to the present embodiment includes a plurality of lenses and constitutes a first optical system and a second optical system.

  The first optical system includes an optical lens group 21, a beam splitter 22, a focus lens 23a, and an image sensor 24a composed of a CCD or the like arranged along the subject optical path shown in FIG. The optical lens group 21 includes three lenses 21a, 21b, and 21c. The beam splitter 22 splits the light from the subject into two, and one light is incident on the image sensor 24a.

  The second optical system includes an optical lens group 21, a beam splitter 22, a focus lens 23b, and an image sensor 24b composed of a CCD or the like. Therefore, the second optical system shares the optical lens group 21 and the beam splitter 22 with the first optical system. The other light split by the beam splitter 22 is incident on the image sensor 24b.

  The image sensor 24a and the image sensor 24b continuously capture images by focus scanning in the moving image shooting mode as described in the first embodiment. For this reason, in the imaging devices 24a and 24b, a range of the subject distance L that can capture an image among all the subject distances L corresponding to the focal position from infinity to the closest distance, that is, a variation range of the focal position is preset. Is done. Thereby, the two image sensors 24a and 24b can capture images at different focal positions (values of the subject distance L) at the same time.

  The setting of the focus position range, that is, the setting of the movement range of the focus lenses 23a and 23b, for example, sets a value of an intermediate subject distance L (hereinafter referred to as “intermediate subject distance Lc”) between infinity and close. Is done. As a result, in the image pickup device 24a and the image pickup device 24b, the area in which the image can be captured is distributed within the shooting range according to the set movement range of the focus lenses 23a and 23b.

  FIG. 15 is a diagram for explaining a range of subject distance values that can be captured by the two image sensors 24a and 24b of FIG.

  In FIG. 15, the vertical axis indicates the subject distance L, that is, the focal position, and the horizontal axis indicates time t. A subject distance La shown in FIG. 15 indicates a focal position set to capture the first main subject within the range of the subject distance that can be captured by the image sensor 24a. As shown in FIG. 15, the image sensor 24 a performs focus scanning within the range of the focal position corresponding to the range from the intermediate subject distance Lc to infinity among the total subject distance L.

  Similarly, the subject distance La ′ indicates the focal position set to image the second main subject within the range of the subject distance that can be captured by the image sensor 24b. As shown in FIG. 15, the image sensor 24 b performs focus scanning within the focal range fluctuation range corresponding to the distance from the closest to the intermediate subject distance Lc of the total subject distance L.

  Therefore, the image pickup devices 24a and 24b are distributed so that the range of focus position variation that can be focused and scanned with the intermediate subject distance Lc as a boundary does not overlap or overlaps only at the focus position corresponding to the intermediate subject distance Lc. Yes.

  The still image captured by the image sensor 24a and the still image captured by the image sensor 24b are stored in a single memory of the recording unit 7 while being synchronized. The stored image is subjected to the same processing as in the first embodiment described above. As a result, as in the first embodiment described above, an image in which a desired subject is clearly captured can be reliably obtained from either the still image aggregate by the image sensor 24a or the still image aggregate by the image sensor 24b. Can be obtained.

  According to the second embodiment, the two image pickup devices 24a and 24b are distributed with a fluctuation range of a focus position that can be focused and scanned. As a result, the time (cycle) required for focus scanning can be halved by halving the image capture time compared to the first embodiment. Alternatively, by making the focus scanning period the same as that of the first embodiment, it is possible to secure twice the image capture time. Moreover, since each image pick-up element 24a, 24b images at each resolution, the resolution of a moving image can be improved.

  In the second embodiment, it is preferable to use, as the imaging devices 24a and 24b, imaging devices with extremely high sensitivity, that is, ultra-high sensitivity. Further, as the lenses 21a, 21b, 21c and the focus lenses 23a, 23b constituting the optical lens group 21, it is preferable to use a bright lens, that is, a highly condensing lens. As a result, the amount of light per time when capturing one image can be increased.

  Hereinafter, a modification of the second embodiment will be described.

  FIG. 16 is a diagram for explaining a range of subject distance values in which two image pickup devices 24a and 24b capture an image in a modification of the second embodiment.

  In the present modification, the image sensor 24a is configured to be able to track a preset first main subject within a predetermined shooting range. It is possible to continue capturing a clear image with respect to the imaging region including the vicinity.

  A subject distance La shown in FIG. 16 indicates a focal position set before the start of photographing so that the image sensor 24a tracks the first main subject within the photographing range. Note that the example shown in FIG. 16 shows a case where the value of the subject distance L does not change greatly, that is, a case where the first subject does not move greatly. Therefore, the focus position of the focus lens 23a is not greatly changed.

  Here, it is preferable that the focal position of the focus lens 23a does not vary greatly. As a result, when an image of a subject in the imaging region captured by the imaging device 24a is displayed on the display 16 in real time, that is, as a moving image, the user performs imaging while confirming the imaging status on the display 16. Can do.

  The subject distance La ′ indicates a focal position set before the start of shooting so that the image pickup device 24b picks up the second subject in a shooting region other than the shooting region of the image pickup device 24a. For example, as illustrated in FIG. 16, the imaging element 24 b performs focus scanning within the range of variation of the focal position corresponding to the distance from the closest to the subject distance La out of the total subject distance L.

  Therefore, in this modification, the focus lenses 23a and 23b of the image pickup devices 24a and 24b are distributed with a focus position variation range that can be focused and scanned with the subject distance La as a boundary.

  Note that the focal ranges of the focus lenses 23a and 23b that can be focused and scanned by the image sensors 24a and 24b may overlap. The reason is that the overlap time in which the focal position fluctuation ranges of the focus lenses 23a and 23b overlap is often very short, and a plurality of frames finally extracted as moving images are captured within the overlap time. This is because there is a low possibility of corresponding to a still image. Therefore, the smoothness of the moving image is hardly impaired during moving image reproduction.

  Finally, the still image captured by the image sensor 24a and the still image captured by the image sensor 24b are stored in a single memory of the recording unit 7 while being synchronized. Thereby, not only can a clear image of the first subject captured by the image sensor 24a be reliably acquired, but also from the still image aggregate by the image sensor 24b, as in the first embodiment described above. An image in which a desired subject is clearly captured can be reliably acquired.

  FIG. 16 shows a case where the subject distance La of the first subject does not vary greatly, but the subject distance La of the first subject may vary greatly. For example, the focus position corresponding to the subject distance of the first subject may change to the infinity side again after changing to the close side. In this case, as described above, the first optical system continues to capture an image at the focal position corresponding to the subject distance of the first main subject by tracking the first main subject. On the other hand, the second optical system continues focus / scan while overlapping with the fluctuation range of the focal position where the image sensor 24a can capture an image.

  In this modification, at least one still image of the still image aggregate acquired by the second optical system may be added to the still image aggregate of the first subject tracked by the first optical system. Alternatively, a frame in which a desired subject is focused from the still image aggregate acquired by the second optical system and at least one still image of the first subject captured by the first optical system are included. You may synthesize.

  In the second embodiment and its modification, the number of image sensors is two, but may be three or more. As a result, it is possible to further shorten the time (scanning time) required to perform focus / scan within the fluctuation range of the focal position corresponding to the total object distance L from infinity to the nearest. When three image sensors are used, each image sensor is associated with a unique color, for example, R (red), G (green), or B (blue). The still images of each color may be combined.

  In the first and second embodiments described above, the digital still camera 100 may have a moving image pan focus function as described below.

  FIG. 17 is a diagram showing a shooting area used to explain the moving image pan focus function of the digital still camera 100 of FIG.

  When the digital still camera 100 is fixed by, for example, a tripod, a shooting area 1700 corresponding to the display area of the display 16 is also fixed as shown in FIG. In the example shown in FIG. 17, the imaging region 1700 is divided into 12 partial regions including partial regions 1720a, 1720b, and 1720c. Plant images 1710a, 1710b, and 1710c are displayed in the partial areas 1720a, 1720b, and 1720c, respectively.

  In FIG. 17, the user designates a partial area on the display 16 when selecting the main subject. As a result, it is possible to obtain an image in which the main subject in the partial area is in focus.

  Specifically, when the user wants to focus on the subject corresponding to the plant image 1710b in the center of the imaging region 1700, that is, the plant, the partial region 1720b is designated. Thereby, a moving image in which the plant corresponding to the plant image 1710b is in focus can be acquired.

  In addition to this, when it is desired to focus on both the short object distance, that is, the front plant (plant image 1710a) and the long object distance, that is, the rear plant (plant image 1710c), the partial region Not only 1720b but also partial areas 1720a and 1720c are designated.

  Furthermore, by specifying all the partial areas, it is possible to acquire a pan-focus-like moving image in which all subjects in the shooting area are in focus (moving image pan-focus function). This moving image pan focus function is automatically set by setting all partial areas in the shooting area 1700.

  Also, as shown in FIG. 17, when a static subject is photographed, when it is desired to focus on a dynamic subject that has jumped into the photographing region 1700, the dynamic recognition is performed by the recognition means described above. The subject may be tracked.

  In the above-described first and second embodiments and their modifications, the lens barrel drive is performed in the process of FIG. 5, but if the focal position can be changed, the lens barrel drive is performed. It does not have to be done.

  In the above embodiment, the frame method has been described. However, the present invention can be similarly applied to the field method. Field systems include the NYSC (National TV Standards Committee) system and the (Phase Alternation Line) system. Further, although the digital still camera 100 performs 20 still image shootings at a high speed by one focus / scan, the number of still image shootings (the number of steps) may not be 20 times. For example, the resolution may be further improved by increasing the number of times of still image shooting more than 20 times. On the other hand, by reducing the number of still image shooting times less than 20, the speed of focus scanning can be further improved and captured. The brightness of each image to be displayed may be improved.

  In the above-described embodiment, the digital still camera 100 includes the strobe 14 and the optical viewfinder 12. However, one or both of the strobe 14 and the optical viewfinder 12 may not be included.

  Moreover, in the said embodiment, the memory of the recording part 7 may be what kind of thing, and plural may be sufficient as it. For example, still image aggregates 700a, 700b, 700c,..., 700n that are likely to be deleted are stored in a volatile storage medium, and moving images 1000, 1100, and 1200 that are likely to be saved are stored in an SD card or CF. It is preferably stored in a portable storage medium such as a (Compact Flash (registered trademark)) card.

  In the above embodiment, the moving image shooting mode of the digital still camera 100 is illustrated, but the present invention may be applied to the still image shooting mode of the digital still camera 100. In addition, the imaging apparatus according to the above embodiment is a digital still camera, but may be a digital video camera (DVC) or the like.

  Also, an object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and a computer (or CPU or MPU) of the system or apparatus. Is also achieved by reading and executing the program code stored in the storage medium.

  In this case, the program code itself read from the storage medium realizes the functions of the above embodiments, and the program code and the storage medium storing the program code constitute the present invention.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, a DVD-RW, and a DVD + RW. Such optical disks, magnetic tapes, nonvolatile memory cards, ROMs, and the like can be used. Alternatively, the program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code Includes a case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

  Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function is determined based on the instruction of the program code. This includes a case where a CPU or the like provided in an expansion board or a function expansion unit performs part or all of actual processing, and the functions of the above-described embodiments are realized by the processing.

1 is a perspective view schematically showing an appearance of a front side of a digital still camera as an imaging apparatus according to a first embodiment of the present invention. It is a perspective view which shows roughly the external appearance of the back side of the digital still camera of FIG. FIG. 2 is a block diagram schematically showing an internal configuration of the digital still camera of FIG. 1. It is a flowchart of the image data process performed by the digital still camera of FIG. It is a flowchart which shows the detail of the image taking-in process performed by FIG.4 S11. It is a figure for demonstrating the focus scan performed by the process of FIG. It is a figure which shows the still image aggregate | assembly comprised by 20 still images image | photographed with the focus position applicable to each object distance acquired by the digital still camera of FIG. FIG. 6 is a diagram used for explaining a subject distance set to stop lens barrel driving in steps S112 and S116 of FIG. It is a figure which shows an example of the measurement result of the contrast value by the contrast measurement part in FIG. It is a figure which shows the new moving image constructed | assembled from the some flame | frame extracted from the some still image aggregate | assembly as shown in FIG. It is a figure which shows the moving image acquired by the 1st modification of 1st Embodiment. It is a figure which shows the moving image acquired by the 2nd modification of 1st Embodiment. It is a flowchart of the image data process performed in order to acquire the moving image of FIG. It is a block diagram which shows roughly the structure of the imaging optical system of the digital still camera as an imaging device which concerns on the 2nd Embodiment of this invention. FIG. 15 is a diagram for describing a range of subject distance values that can be captured by the two image pickup devices of FIG. 14. FIG. 10 is a diagram for explaining a range of subject distance values in which two image pickup devices capture an image in a modification of the second embodiment. It is a figure which shows the imaging | photography area | region used in order to demonstrate the moving image pan focus function of the digital still camera of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Camera microcomputer 2 Image pick-up part 3 Contrast comparison part 4 Contrast measurement part 6 Image display part 7 Recording part 8 Data processing part 9 Subject instruction part 11 Lens barrel 21 Optical lens group 23a, 23b Focus lens 24a, 24b Image pick-up element 100 Digital still camera 700, 700a to 700n
800, 800a to 800n, 810a to 810n Frame 820a to 820n Composite frame 1000, 1100, 1200

Claims (6)

Image signal output means for outputting an image signal in response to light from the subject;
A focus lens control means for moving the focus lens;
Storage means for storing an image based on the image signal from the image signal output means;
The memory operation of the focus lens plurality of images in focus at different distances by moving in a predetermined range to get stored in the storage unit to repeatedly periodically by the focus lens control unit, an acquisition unit configured to acquire a plurality of images in focus focus image or the second object combined with the first object on the basis of the one period to the user's selection of the image corresponding stored as 1 frame,
A moving image constructing unit configured to construct a moving image by arranging the images acquired as the one frame, and storing the moving image in the storage unit;
After the moving image constructed by the moving image constructing unit is stored in the storage unit, the focused image is focused on the first subject or the second subject not selected by the user. In order to allow the moving image construction means to construct an image as a moving image, the storage means as a still image aggregate for a plurality of images acquired by the storage operation repeated periodically. An image pickup apparatus comprising: a still image storage unit that stores the image. The imaging unit according to claim 1, wherein the acquisition unit includes a combination unit that acquires a combined image obtained by combining an image focused on the first subject and an image focused on the second subject. apparatus. The imaging apparatus according to claim 2, further comprising reproduction means for reproducing the moving image. An image signal output step for outputting an image signal according to light from the subject, a focus lens control step for moving the focus lens, and a memory for storing an image based on the image signal output from the image signal output step in a storage means An imaging method for acquiring an image using steps,
Just repeat storage operation of storing and acquiring a plurality of images in focus at different distances by moving in a predetermined range of the focus lens by the focus lens control step in the storage unit periodically, an acquisition step of acquiring a plurality of images in focus focus image or the second object combined with the first object on the basis of the one period to the user's selection of the image corresponding stored as 1 frame,
Constructing a moving image by arranging the images acquired as the one frame, and storing the moving image in the storage unit;
After the moving image constructed in the moving image constructing step is stored in the storage means, the image focused on the first subject that has not been selected by the user or focused on the second subject Still image storage for storing a plurality of images acquired by the periodically repeated storage operation as a still image aggregate in the storage means for each period so that an image can be constructed as a moving image And an imaging method comprising: steps . An image signal output step for outputting an image signal according to light from the subject, a focus lens control step for moving the focus lens, and a memory for storing an image based on the image signal output from the image signal output step in a storage means A program for causing a computer to execute an imaging method for acquiring an image using steps,
The imaging method is:
Just repeat storage operation of storing and acquiring a plurality of images in focus at different distances by moving in a predetermined range of the focus lens by the focus lens control step in the storage unit periodically, an acquisition step of acquiring a plurality of images in focus focus image or the second object combined with the first object on the basis of the one period to the user's selection of the image corresponding stored as 1 frame,
Constructing a moving image by arranging the images acquired as the one frame, and storing the moving image in the storage unit;
After the moving image constructed in the moving image constructing step is stored in the storage means, the image focused on the first subject that has not been selected by the user or focused on the second subject Still image storage for storing a plurality of images acquired by the periodically repeated storage operation as a still image aggregate in the storage means for each period so that an image can be constructed as a moving image program, characterized in that it comprises the steps, a. A computer-readable storage medium storing the program according to claim 5 .

Images