JP2017183983A - Imaging apparatus, control method and control program of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily adjust an angle-of-view of even a subject which needs imaging with long second exposure and high magnification like a celestial body.SOLUTION: A camera 300 consecutively displays, on a display part 311, images obtained by imaging a subject such as a celestial body. At this time, a motion detection part 316 detects a motion of the camera and when the motion detection part detects the motion of the camera, an entire control arithmetic part 309 displays on the display part the image obtained on the basis of a frame before a frame where the motion is detected.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an imaging apparatus, a control method thereof, and a control program, and more particularly, to driving of an imaging element provided in the imaging apparatus.

  In recent years, in an imaging apparatus such as a digital camera, high ISO sensitivity and long exposure (long-second exposure) can be set by increasing sensitivity and reducing noise of an image sensor. For this reason, even if the user's photography technique is not high, it is possible to relatively easily perform shooting in a scene that requires high-sensitivity and long-second exposure such as a night view or night sky.

  For example, when a panning operation is performed to change the angle of view, there is an imaging device that increases sensitivity, increases the frame rate, and shortens the exposure time (see Patent Document 1). As a result, in this imaging apparatus, image blur is reduced to obtain a continuous image in which the influence of the blur is suppressed.

JP 2008-92047 A

  However, even if the frame rate is lowered, it is extremely difficult to capture the subject itself at a desired angle of view when photographing a very small and dark subject such as an astronomical object in a dark scene.

  Usually, when taking a picture, the angle of view is adjusted while viewing an optical viewfinder or a display monitor provided in the camera. When the subject brightness is low, such as a celestial body, and its size is small, the celestial body cannot be captured by the optical viewfinder unless the brightness is visible to the naked eye.

  When the display monitor unit is used, it is possible to display the celestial body as a live view if the exposure time is increased. However, when a camera panning operation for adjusting the angle of view is performed, the exposure time is long, and the position of the celestial body that is the subject moves, so that the exposure amount is insufficient. As a result, the celestial body cannot be displayed as an image, making it difficult to adjust the angle of view.

  In other words, image blurring can be suppressed by increasing the sensitivity and shortening the exposure time. On the other hand, in a scene such as a night view or night sky, the sensitivity is already increased and the exposure time is long. For this reason, when shooting with higher sensitivity, the image is noisy and difficult to use as a live view image. In particular, the image quality becomes extremely worse for a point-like subject such as a celestial body.

  Accordingly, an object of the present invention is to provide an imaging apparatus capable of easily adjusting the angle of view even for a subject that needs to be photographed at a high magnification with a long exposure such as an astronomical object, a control method thereof, and a control program. There is to do.

  In order to achieve the above object, an imaging apparatus according to the present invention is an imaging apparatus that continuously displays images obtained by imaging a subject on a display unit, and detects a change in the angle of view of the imaging apparatus. When a change in the angle of view is detected by the detection means and the detection means when imaging the subject, an image of a frame before the frame in which the change in the angle of view is detected is displayed on the display unit. And a control means.

  According to the present invention, it is possible to easily perform angle-of-view adjustment even on a subject such as a celestial body that needs to be photographed at a high magnification with long exposure.

1 is a block diagram illustrating a configuration of an example of an imaging apparatus according to a first embodiment of the present invention. 4 is a flowchart for explaining an example of live view display performed by the camera shown in FIG. 1. FIG. 3 is a flowchart for explaining processing in display mode 1 shown in FIG. 2. FIG. 3 is a flowchart for explaining processing in display mode 2 shown in FIG. 2. It is a flowchart for demonstrating the process which concerns on the motion detection shown in FIG. It is a figure which shows an example of the display image when panning operation | movement is performed in the camera shown in FIG. It is a figure which shows an example of the display image obtained by the division | segmentation exposure when panning operation | movement is performed. It is a figure which shows the relationship between the panning operation | movement at the time of obtaining the display image shown in FIG. 7, and exposure timing. It is a flowchart for demonstrating an example of the process which concerns on the display mode 1 performed in the 2nd Embodiment of this invention. FIG. 10 is a flowchart for explaining an addition synthesis process shown in FIG. 9. FIG. It is a figure for demonstrating the addition number of the image area | region performed with the camera by the 2nd Embodiment of this invention, (a) is a figure which shows the setting of an image area, (b) is a figure which shows a region number addition map It is. It is a figure which shows an example of the live view display of the image obtained with the camera by the 2nd Embodiment of this invention. It is a figure which shows the relationship between a to-be-photographed object and an angle of view at the time of performing the panning operation | movement of a camera. It is a figure which shows the relationship between the panning operation | movement of a camera, and exposure timing.

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

  First, before describing the imaging apparatus according to the embodiment of the present invention, the relationship between the subject and the angle of view and the exposure timing when the panning operation is performed will be described.

  FIG. 13 is a diagram illustrating the relationship between the subject and the angle of view when the panning operation of the camera is performed.

  In the image 800, an angle of view when a starry sky is captured as a subject is shown. Assume that the photographer changes the angle of view from the angle of view 801 to the angle of view 802. In the illustrated example, an angle of view common to both the angle of view 801 and the angle of view 802 is an angle of view 803. When the camera is at rest with the angle of view 801, a celestial body indicated by an image 811 is displayed on the display monitor as a live view.

  Assume that the photographer performs a panning operation of the camera at this angle of view 802 from this state. As described above, when a celestial body is displayed in live view, a sufficient exposure time is required to obtain one image. For this reason, when the display image when the camera is stationary at the final angle of view 802 is the image 814, the image 812 and the image 813 that are images during the panning operation cannot obtain a sufficient exposure amount. As a result, it becomes difficult to display the celestial body as an image. In other words, although the panning operation is originally intended to adjust the angle of view, the photographer cannot see the essential subject, and as a result, it becomes difficult to adjust the angle of view.

  FIG. 14 is a diagram illustrating the relationship between the panning operation of the camera and the exposure timing.

  In FIG. 14, the horizontal axis indicates the passage of time, and times T901 to 905 indicate the exposure start timing for live view. The exposure periods of the frames are indicated by exposures 911 to 914. Furthermore, timings T901 'to 904' indicate the timing at which an image generated according to the image obtained as a result of exposure in exposures 911 to 914 is displayed as a live view.

  Images taken in the exposures 911 to 914 are images 811 to 814 shown in FIG. In FIG. 14, a curve 910 indicates the amount of camera movement, and a panning operation for adjusting the angle of view is performed in a section where the amount of camera movement is large. In other words, the panning operation of the camera is performed in a period immediately before time T <b> 902 and immediately after time T <b> 904. As can be easily seen from the curve 910 indicating the camera movement amount, in the exposure 911 and the exposure 914, the movement amount of the camera is zero and the camera is stationary.

  Therefore, the image 811 and the image 814 shown in FIG. 13 are celestial images without blurring in a stationary state. On the other hand, in exposure 912 and exposure 913, exposure is performed during a period in which the amount of camera movement is large and the panning operation is performed. As a result, as shown in the image 812 and the image 813 even when the exposure time is the same, it is not possible to obtain a celestial image without blurring in a stationary state.

[First Embodiment]
FIG. 1 is a block diagram showing the configuration of an example of an imaging apparatus according to the first embodiment of the present invention. In the following description, a live view display (continuous display) when the photographer performs a panning operation to change the angle of view when shooting a low-light starry sky scene will be described as an example.

  The illustrated imaging device is, for example, a digital camera (hereinafter simply referred to as a camera), and includes a lens unit (hereinafter simply referred to as a lens). The amount of light of the subject image (optical image) that has passed through the lens 301 is adjusted by a diaphragm 304 via a mechanical shutter (mechanical shutter) 303. The optical image is formed on the imaging surface of the image sensor 306.

  The image sensor 306 includes a plurality of photodiodes (PD) arranged in a two-dimensional matrix. The image sensor 306 generates an electrical signal (analog signal) corresponding to the optical image by photoelectric conversion. Further, the image sensor 306 adjusts the gain of the analog signal, converts the analog signal into a digital signal by A / D conversion, and sends it to the image signal processing circuit 307 as R, Gr, Gb, and B signals.

  The imaging signal processing circuit 307 performs image signal processing such as low-pass filter processing, shading processing, and WB processing for reducing noise on a digital signal (image data), and also performs image correction, image composition, compression, and the like. .

  The overall control calculation unit 309 controls the entire camera. For example, the overall control calculation unit 309 performs zoom and focus control by driving the lens 301 by the lens driving unit 302. Further, the overall control calculation unit 309 controls driving of the mechanical shutter 303 and the diaphragm 304 by the shutter / diaphragm driving unit 305.

  In the first memory unit (memory unit I) 308, an imaging signal that is an output of the imaging signal processing circuit 307 is temporarily stored as image data. The overall control calculation unit 309 records image data on the recording medium 312 by the recording medium control interface unit (recording medium control I / F unit) 310 and reads out the image data recorded on the recording medium 312. As the recording medium 312, for example, a detachable semiconductor memory is used. The display unit 311 displays an image corresponding to the image data.

  An external interface unit (external I / F unit) 313 is an interface for communicating with an external device such as an external computer. The second memory unit (memory unit II) 314 stores the calculation results by the overall control calculation unit 309 and various parameters. When the photographer sets conditions (shooting conditions) regarding shooting using the operation unit 315, the overall control calculation unit 309 controls the camera 300 based on the shooting conditions.

  The motion detection unit 316 detects or detects the motion of the camera 300, detects the movement direction and the movement amount when the camera 300 moves, and sends motion data indicating the movement direction and the movement amount to the overall control calculation unit 309. The overall control calculation unit 309 calculates the change amount of the subject angle of view based on the motion data as described later.

  FIG. 2 is a flowchart for explaining an example of live view display performed by the camera shown in FIG.

  When the live view mode is started, the overall control calculation unit 309 initializes various parameters based on setting information (that is, shooting conditions) input from the operation unit 315 by the photographer (step S201). Then, the overall control calculation unit 309 records the initialized parameters in the memory unit II 314.

  Subsequently, when the setting information is changed in the operation unit 315, the overall control calculation unit 309 acquires the change in the setting information and reflects the change in various parameters (step S202). For example, when the setting of the lens 301 and the aperture 304 is changed, the overall control calculation unit 309 changes the lens position and the aperture value according to the setting change by the lens driving unit 302 and the shutter / aperture driving unit 305. Then, the overall control calculation unit 309 records the parameter reflecting the change of the lens position and the aperture value in the memory unit II 314.

  Next, based on the parameters recorded in the memory unit II 314, the overall control calculation unit 309 determines whether or not it is long-second shooting (step S203). Here, the overall control calculation unit 309 determines whether or not the exposure time Tv set by the photographer is Tv ≧ Tvth (Tvth: constant (threshold)). That is, the overall control calculation unit 309 determines whether or not the exposure time is greater than or equal to a predetermined threshold value.

  If Tv ≧ Tvth, that is, if long-time shooting has been performed (YES in step S203), the overall control calculation unit 309 executes a first display mode (display mode 1) described later (step S204). On the other hand, if Tv <Tvth, that is, it is less than the threshold value and the long-second shooting is not performed (NO in step S203), the overall control calculation unit 309 executes a second display mode (display mode 2) described later. (Step S205).

  After the process of step S204 or S205, the overall control calculation unit 309 determines whether there is an instruction to end the live view display (step S206). When there is an end instruction (YES in step S206), overall control calculation unit 309 ends the live view mode. On the other hand, if there is no termination instruction (NO in step S206), overall control operation unit 309 returns to the process in step S202. In step S206, for example, when the power is turned off by the operation unit 315, the overall control calculation unit 309 is instructed to end.

  FIG. 3 is a flowchart for explaining processing in the display mode 1 shown in FIG.

  When the display mode 1 is started, the overall control calculation unit 309 acquires imaging conditions such as the exposure time Tv, the aperture value Av, and the gain G recorded in the memory unit II 314, and parameters relating to the image sensor driving mode and the like. The overall control calculation unit 309 starts shooting by driving the image sensor 306 by live view mode driving based on the parameter (step S101).

  Subsequently, the overall control calculation unit 309 performs motion detection for determining whether or not the camera 300 has moved based on the parameters recorded in the memory unit II 314 and the motion data obtained by the motion detection unit 316 (step S102). ). Although the motion detection will be described later, in this motion detection, the overall control calculation unit 309 obtains a motion determination flag M. Here, it is assumed that the camera 300 has moved when the motion determination flag M = 1. If the motion determination flag M = 0, it is assumed that the camera 300 has not moved.

  Next, the overall control calculation unit 309 determines whether or not the motion determination flag M obtained by motion detection is M = 1 (step S103). If motion determination flag M = 1 (YES in step S103), overall control calculation unit 309 resets the imaging operation (step S104). Here, if shooting is in progress, the overall control calculation unit 309 stops driving the image sensor 306 and initializes the image sensor 306. When shooting is completed, the overall control calculation unit 309 discards the image shot when motion is detected.

  Thereafter, the overall control calculation unit 309 cuts out the image and changes the display area (step S105). Here, the overall control calculation unit 309 first obtains the raw image data Rb used for the display image in the frame before the motion is detected. Then, the overall control calculation unit 309 generates Raw image data Rd to be used as the display image Id based on the view angle movement amounts Δx and Δy from the previous frame and the Raw image data Rb. In addition, Δx and Δy represent the amount of movement in the horizontal direction and the vertical direction by the number of pixels (unit: pixel), and further indicate the direction of movement by + or −.

  For example, the overall control calculation unit 309 moves the angle of view with respect to the raw data image Rb by Δx in the horizontal direction and Δy in the vertical direction. Then, for an area where no data exists on the image, the overall control calculation unit 309 generates the raw image data Rd by supplementing the pixel value with 0 or any other value. Thereafter, the overall control calculation unit 309 performs signal processing on the raw image data Rd by the imaging signal processing circuit 307 to obtain a display image Id.

  If the motion determination flag M is not 1 (NO in step S103), that is, if the motion determination flag is 0, the overall control calculation unit 309 determines whether or not the photographing operation has ended (step S106). If the shooting operation is not completed (NO in step S106), overall control calculation unit 309 waits. On the other hand, when the photographing operation ends (YES in step S106), the overall control calculation unit 309 generates Raw image data Rd based on the image signal read from the image sensor 306. Then, the overall control calculation unit 309 performs signal processing on the raw image data Rd by the imaging signal processing circuit 307 to obtain a display image Id (step S107).

  After the process of step S105 or S107, the overall control calculation unit 309 displays the display image Id as the image Xi on the display unit 311 (step S108). Then, the overall control calculation unit 309 ends the display mode 1.

  FIG. 4 is a flowchart for explaining processing in the display mode 2 shown in FIG.

  When the display mode 2 is started, the overall control calculation unit 309 acquires imaging conditions such as the exposure time Tv, the aperture value Av, and the gain G recorded in the memory unit II 314, and parameters relating to the image sensor driving mode. The overall control calculation unit 309 starts shooting by driving the image sensor 306 by live view mode driving based on the parameter (step S401).

  Subsequently, the overall control calculation unit 309 generates Raw image data Rd based on the image signal read from the image sensor 306. Then, the overall control calculation unit 309 performs signal processing on the raw image data Rd by the imaging signal processing circuit 307 to obtain a display image Id. The overall control calculation unit 3092 displays the display image Id as the image Xi on the display unit 311 (step S202). Thereafter, the overall control calculation unit 309 ends the display mode 2.

  FIG. 5 is a flowchart for explaining processing related to motion detection shown in FIG.

  When motion detection is started, the overall control calculation unit 309 acquires motion data from the motion detection unit 316 (step S501). Then, the overall control calculation unit 309 reads the movement direction φ and the movement amount θ, which are parameters related to the movement of the camera 300 stored in the memory unit II 314.

  Subsequently, the overall control calculation unit 309 obtains the view angle movement amounts Δx and Δy as follows (step S502). Here, the overall control calculation unit 309 first reads the sensor pixel pitch P from the memory unit II 314 (the sensor pixel pitch P refers to the pitch of the pixels provided in the image sensor 306). Then, the overall control calculation unit 309 calculates the field angle movement amounts Δx and Δy based on the sensor pixel pitch P, the exposure time Tv and the focal length f, the movement direction φ, and the movement amount θ, which are the above-described photographing conditions.

  Next, the overall control calculation unit 309 determines “no motion” if the field angle movement amounts Δx and Δy satisfy the following expression (1) with respect to the motion determination threshold Мth, and “no motion” otherwise. Motion determination is performed (step S503).

Мth ≧ (Δx ² , Δy ² ) ^1/2 (1)
Note that the motion determination threshold Мth is Мth = 1 (pixel) considering that the subject appears to be blurred when the angle of view moves even on one pixel on the image. Actually, in the live view mode, image signals are not read out from all the pixels of the image sensor 306 but are read out every several pixels. Therefore, the motion determination threshold Мth may be set to several pixels.

  Next, the overall control calculation unit 309 determines whether or not the determination result in step S503 is “with motion” (step S504). If it is “with motion” (YES in step S504), overall control calculation unit 309 sets motion determination flag M = 1 (step S505). Then, the overall control calculation unit 309 ends the motion detection. On the other hand, if “no motion” (NO in step S504), the overall control calculation unit 309 sets the motion determination flag M = 0 (step S506). Thereafter, the overall control calculation unit 309 ends the motion detection.

  6 is a diagram showing an example of a display image when a panning operation is performed in the camera shown in FIG.

  Now, as described with reference to FIG. 13, it is assumed that the angle of view is changed from the angle of view 801 to the angle of view 802 as a result of the panning operation performed by the photographer. In this case, in the camera 300 shown in FIG. 1, the image shown in FIG. 6 is displayed as a live view on the display unit 311 as a result of the above-described processing.

  Images 1011 to 1014 indicate display images displayed on the display unit 311 from time T901 'to T904' (see FIG. 14), respectively. In FIG. 6, as a matter of course, there is no fluctuation in the angle of view for the images 1011 and 1014 which are live view display images immediately after the exposure period in which there is no change in the angle of view. Further, there is no blurring in the image 1012 and the image 1013 that are displayed in live view at times T902 'and T903' that are during or immediately after the panning operation.

  As described above, in the first embodiment of the present invention, when it is necessary to shoot with a long second exposure like an astronomical object, a blur-free image is displayed as a live view even during or immediately after the panning operation. can do. As a result, the photographer can easily adjust the angle of view.

[Second Embodiment]
Subsequently, an example of a camera according to the second embodiment of the present invention will be described. The configuration of the camera according to the second embodiment is the same as that of the camera shown in FIG.

  As a technique for ensuring the output of a necessary image signal when photographing a low-illuminance subject, for example, there is a technique (first technique) for sufficiently increasing the exposure time when photographing. Furthermore, there is a technique (second technique) of adding a plurality of images obtained by photographing the same photographing scene with a predetermined exposure time, that is, a technique of performing divided exposure.

  In the first embodiment described above, an image for one frame to be displayed as a live view is generated from one image obtained by long-second exposure using the first technique. On the other hand, in the second embodiment, an image to be displayed as a live view is generated using the second method.

  First, problems in performing divided exposure will be described.

  FIG. 7 is a diagram illustrating an example of a display image obtained by the divided exposure when the panning operation is performed. FIG. 8 is a diagram showing the relationship between the panning operation and the exposure timing when the display image shown in FIG. 7 is obtained.

  In the example illustrated in FIG. 7, as described in FIG. 13, it is assumed that the photographer performs a panning operation and changes the angle of view from the angle of view 801 to the angle of view 802.

  In FIG. 8, the horizontal axis indicates the passage of time, and times T1101 to T1107 indicate the exposure start timing for live view. The exposure periods of the frames are indicated by exposures 1111 to 1117. Furthermore, timings at which display of images generated according to the images obtained as a result of exposure in exposures 1111 to 1117 as live views are started are indicated by T1101 'to 1107'.

  Live view images displayed at times T1101 'to T1107' are images obtained by adding and synthesizing three frames of images up to immediately before the start of display. For example, the display image displayed at T1103 'is obtained by adding and combining frames whose exposure periods are exposure 1111 to exposure 1113. Display images displayed on the display unit 311 at timings T1101 'to T1107' are images 1201 to 1207 shown in FIG.

  In FIG. 8, the curve indicates a change in the amount of motion of the camera 300, and a section where the amount of motion of the camera 300 is large is a section where a panning operation for adjusting the angle of view is performed. In the example illustrated in FIG. 8, the panning operation is performed in a period just before time T1104 to immediately before time T1105.

  As can be easily understood from the camera movement amount 1110, the exposure 1114 has a large movement amount of the camera 300 and is exposed during the panning operation. For this reason, an image taken in the exposure 1114 has a large image blur. For this reason, when divided exposure is performed, that is, when image synthesis is performed, it is not possible to obtain a blur-free image for the images 1204 to 1206 used for the display image.

  In the second embodiment of the present invention, when divided exposure is used when shooting an object with low illuminance, an image without blurring is obtained as a live view even if a panning operation is performed.

  In the second embodiment as well, panning operation from the angle of view 801 to the angle of view 802 is performed because the photographer changes the angle of view when shooting a low-light starry sky scene like the image 800 shown in FIG. The case will be described. Further, here, for convenience of explanation, a description will be given of a change in the angle of view that can be expressed by a horizontal movement and a vertical movement with respect to the angle of view when the camera 300 is activated.

  The live view display described in FIG. 2 is also performed in the camera according to the second embodiment. And in 2nd Embodiment, the process which concerns on the display mode 1 differs from 1st Embodiment.

  FIG. 9 is a flowchart for explaining an example of processing according to the display mode 1 performed in the second embodiment of the present invention. In FIG. 9, the same steps as those in the flowchart shown in FIG. 3 are denoted by the same reference numerals, and description thereof is omitted.

  When the display mode 1 is started, the overall control calculation unit 309 performs the process of step S101 described in FIG. However, here, the total exposure time of the plurality of images may be the exposure time Tv. Therefore, assuming that the exposure time when shooting one image is Tvs and the number of images to be added is N, the exposure time Tvs is expressed by the following equation (2).

Tvs = Tv / N (2)
Subsequently, the overall control calculation unit 309 performs the processing of steps S102 and S103 described in FIG. If the motion determination threshold value M = 1 (YES in step S103), the overall control calculation unit 309 performs the process of step S105 described in FIG.

  On the other hand, if the motion determination threshold value M = 0 (NO in step S103), the overall control calculation unit 309 performs an addition synthesis process for synthesizing a plurality of images as will be described later, and performs a synthesized image (Raw). Image data Rd) is obtained (step S601). Then, the overall control calculation unit 309 performs the process of step S107 described in FIG.

  After the process of step S105 or S107, the overall control calculation unit 309 updates the area addition number map as described later (step S602). After that, the overall control calculation unit 309 performs the process of step S108 described with reference to FIG.

  FIG. 10 is a flowchart for explaining the addition synthesis process shown in FIG.

  Here, a display image to be displayed on the display unit 311 is generated by combining a plurality of images. At this time, the overall control calculation unit 309 generates a display image by sequentially adding and combining images until the number of combined images reaches N (N is an integer of 2 or more). When the number of combined images exceeds N, the overall control calculation unit 309 increases the weight of the latest image and performs an averaging process to generate a display image.

  If the angle of view is not changed, the overall control calculation unit 309 may record the number of combined images in the memory unit II 314 and perform addition / synthesis processing based on the number of images, but if the angle of view is changed, Therefore, the number of synthesized images differs for each image area (image area). Therefore, when the angle of view is changed, the overall control calculation unit 309 records the number of combined images for each region in the memory unit II 314, and varies the addition / combination processing for each region according to the recording.

  Referring to FIG. 10, when the addition synthesis process is started, overall control operation unit 309 first sets variable i = ir0 and variable j = jr0 (step S701). Variables i and j indicate the horizontal and vertical positions of the image, and specify the region when the image is divided into a plurality of regions. Further, ir0 and jr0 indicate the positions in the absolute coordinates of the area located at the upper left corner of the image at the time of shooting by changing the angle of view. The variable i is called a horizontal area address, and the variable j is called a vertical area address.

  FIG. 11 is a diagram for explaining the addition number of image areas performed by the camera according to the second embodiment of the present invention. FIG. 11A is a diagram showing the setting of image regions, and FIG. 11B is a diagram showing a region number addition map.

  As shown in FIG. 11A, the overall control calculation unit 309 sets an absolute coordinate system having the origin at the upper left corner of the angle of view captured by the lens 301 at the time of the first shooting. The overall control calculation unit 309 sets an image area having a predetermined size in contact with the origin as the area (0, 0). Then, the overall control calculation unit 309 divides the image with a predetermined size and sets a plurality of image areas. In the illustrated example, the area (0, 0) to the area (4, 4) are set.

  Assuming that the angle of view captured by the lens 301 at a certain time is a frame surrounded by a thick black line in FIG. 11A, the region (ir0, jr0) at that time is the region (1, 1). Become. That is, the overall control calculation unit 309 sets i = 1 and j = 1.

  Referring to FIG. 10 again, after the process of step S701, overall control operation unit 309 moves to process area (i, j), which is an area to be processed (step S702). Then, the overall control calculation unit 309 determines whether or not the processing area (i, j) is a new view angle area (view angle area) (step S703). Note that the new field angle area refers to an area captured at the field angle at the time of the first shooting after switching from the other display mode to the display mode 1.

  If it is not a new field angle area (NO in step S703), that is, if it is an area obtained (captured) in a previous frame, the overall control calculation unit 309 adds 1 to the image addition number k (step S704). ). Then, the overall control calculation unit 309 determines whether or not the pixel addition number k ≦ the combined number N (step S705).

  If it is a new field angle area (YES in step S703), that is, if it is an area that has never been obtained (has not been photographed) in the previous frame, the overall control calculation unit 309 has the image addition number k. = 1 (step S706). Then, the overall control calculation unit 309 sets the image data Xij obtained in step S101 as partial image data Xij for a display image (step S707). Thereafter, the overall control calculation unit 309 proceeds to the process of step S710 described later.

  When the pixel addition number k ≦ the composite number N (YES in step S705), the overall control calculation unit 309 adds the partial image data Xij and the partial image data Xij-1 of the previous frame, and displays the display image. Partial image data is set (step S708).

  When the pixel addition number k> the composite number N (NO in step S705), the overall control calculation unit 309 uses the partial image data Xij and the partial image data Xij-1 of the previous frame, and uses the following equation (3 ) To obtain partial image data of the display image (step S709).

Xij = Xij-1 * N / (N + 1) + Xij * 1 / (N + 1) (3)
Subsequently, the overall control calculation unit 309 determines whether or not the horizontal area address i = the maximum value imax for the area included in the angle of view captured by the lens 301 (step S710). If i = imax (YES in step S710), overall control calculation unit 309 determines whether vertical area address j = maximum value jmax is satisfied (step S711). In the example shown in FIG. 11A, since there are three regions in the horizontal direction and three regions in the vertical direction and region (ir0, jr0) = region (1, 1), imax = 3 and jmax = 3. It becomes.

  If i is not imax (NO in step S710), overall control operation unit 309 adds 1 to horizontal area address i (step S712). Then, the overall control calculation unit 309 returns to the process of step S702.

  If vertical area address j = not maximum value jmax (NO in step S711), overall control operation unit 309 adds 1 to vertical area address j (step S713). Then, the overall control calculation unit 309 sets the horizontal area address i to the initial value i0 (step S714). Thereafter, the overall control calculation unit 309 returns to the process of step S702.

  If vertical area address j = maximum value jmax (YES in step S711), overall control calculation unit 309 joins the partial image data to generate Raw image Rd (step S715). Then, the overall control calculation unit 309 ends the addition synthesis process.

  Here, the region number addition map will be described with reference to FIG. As shown in FIG. 11B, the area number addition map is a map in which a subject (here, a space, that is, an image) is divided into a plurality of areas, and the addition number k is recorded for each area.

  The image shown in FIG. 11A is divided into 20 areas (0, 0) to (4, 4), and the areas (0, 0) to (4, 4) are respectively shown in FIG. 20 areas shown in FIG. In the example shown in the figure, the region (0, 0) addition number k is 0, and the region (1, 1) addition number k is N + 1.

  FIG. 12 is a diagram illustrating an example of a live view display of an image obtained by the camera according to the second embodiment of the present invention.

  Now, as described with reference to FIG. 13, it is assumed that the photographer performs the panning operation of the camera 300 and changes the angle of view from the angle of view 801 to the angle of view 802. At this time, the relationship between the panning operation and the exposure timing is as described with reference to FIG. 8, and the display images displayed on the display unit 311 at the timings T1101 ′ to T1107 ′ are images 1401 to 1407 shown in FIG. .

  An image 1401 to an image 1403 and an image 1407 are the same as the image 1201 to the image 1203 and the image 1207 shown in FIG. The overall control calculation unit 309 generates a live view display image based on three frames of images obtained immediately before the start of live view.

  On the other hand, the overall control calculation unit 309 generates the image 1404 based on the Raw image Rd used for generating the image 1403. The overall control calculation unit 309 generates the image 1405 based on the raw image Rd used for generating the image 1404 and the image obtained by the exposure 1115. Further, the overall control calculation unit 309 generates the image 1406 based on the raw image Rd used for generating the image 1405 and the image obtained by the exposure 1116.

  As illustrated in FIG. 8, when the panning operation is performed from slightly before time T1104 to immediately after time T1105, in the example illustrated in FIG. 7, the images 1204 to 1206 are blurred. On the other hand, in the example illustrated in FIG. 12, no blurring occurs in the images 1404 to 1406.

  As described above, in the second embodiment of the present invention, when a subject that needs to be shot with long-second exposure is shot with divided exposure, an image without blurring is displayed even during or immediately after the panning operation. Can be displayed. As a result, the photographer can easily adjust the angle of view.

  In the above-described second embodiment, the example in which the number of additions for each image area is recorded as the area number addition map has been described. However, the number of additions for each pixel may be recorded, and other methods may be used. May be.

  In the above-described embodiment, the exposure time Tv when the photographer shoots in the live view mode is specified in advance. However, the exposure mode is selected by selecting a mode specialized for camera long-time shooting as the camera shooting mode. You may make it designate time indirectly. Further, the exposure time Tv may be determined by AE (automatic exposure adjustment) or the like.

  As is clear from the above description, in the example shown in FIG. 1, the overall control calculation unit 309 and the motion detection unit 316 function as detection means, and the overall control calculation unit 309 functions as control means. Further, the overall control calculation unit 309 and the imaging signal processing circuit 307 function as a synthesis unit.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to these embodiment, Various forms of the range which does not deviate from the summary of this invention are also contained in this invention. .

  For example, the function of the above embodiment may be used as a control method, and this control method may be executed by the imaging apparatus. Further, a program having the functions of the above-described embodiments may be used as a control program, and the control program may be executed by a computer included in the imaging apparatus. The control program is recorded on a computer-readable recording medium, for example.

[Other Embodiments]
A program that realizes one or more functions of the above-described embodiments is supplied to a system or apparatus via a network or a storage medium. The present invention can also be realized by a process in which one or more processors in the computer of the system or apparatus read and execute the program. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

DESCRIPTION OF SYMBOLS 301 Lens 302 Lens drive part 303 Mechanical shutter 304 Diaphragm 305 Shutter / aperture drive part 306 Imaging element 307 Imaging signal processing circuit 309 Overall control calculation part 311 Display part 316 Motion detection part

Claims (9)

An imaging device that continuously displays images obtained by imaging a subject on a display unit,
Detecting means for detecting a change in the angle of view of the imaging device;
Control means for displaying an image of a frame before the frame in which the change in the angle of view is detected on the display unit when the change in the angle of view is detected by the detection means when the subject is imaged; ,
An imaging device comprising:   The control means detects the change in the angle of view when the change in the angle of view is detected by the detection means when the exposure time when the subject is imaged is equal to or greater than a predetermined threshold. The image pickup apparatus according to claim 1, wherein an image of a frame prior to the frame is displayed on the display unit.   The control unit displays each image of a frame on the display unit when the exposure time is less than the threshold value or when the change of the angle of view is not detected by the detection unit. The imaging device described in 1.   The imaging device according to any one of claims 1 to 3, wherein the detection unit moves the imaging device when the change in the angle of view does not satisfy a predetermined condition. .   The control means displays an image on the display unit according to the change in the angle of view when displaying an image of a frame before the frame in which the change in the angle of view is detected on the display unit. The imaging apparatus according to claim 1, wherein the imaging apparatus is characterized. Comprising a combining means for combining a plurality of frames to obtain a combined image;
The imaging apparatus according to claim 2, wherein the control unit displays a synthesized image obtained by the synthesizing unit on the display unit when a change in the angle of view is not detected by the detecting unit.   The imaging apparatus according to claim 6, wherein the control unit does not use a frame when the change of the angle of view is detected by the detection unit for image synthesis by the synthesis unit. A method for controlling an imaging apparatus that continuously displays images obtained by imaging a subject on a display unit,
A detection step of detecting a change in the angle of view of the imaging device;
A control step of displaying an image of a frame before the frame in which the change in the angle of view is detected on the display unit when the change in the angle of view is detected in the detection step when the subject is imaged; ,
A control method characterized by comprising: A control program used in an imaging apparatus that continuously displays images obtained by imaging a subject on a display unit,
In the computer provided in the imaging device,
A detection step of detecting a change in the angle of view of the imaging device;
A control step of displaying an image of a frame before the frame in which the change in the angle of view is detected on the display unit when the change in the angle of view is detected in the detection step when the subject is imaged; ,
A control program characterized by causing