JP6103481B2 - Imaging apparatus, and control method and program thereof - Google Patents

Description

The present invention relates to an imaging apparatus, a control method therefor, and a program, and more particularly to a technique for improving the quality of a moving image during moving image shooting.

  2. Description of the Related Art Conventionally, some imaging devices can change the frame rate during moving image shooting. In such an imaging device, for example, while shooting at a low frame rate, only a specific shooting scene in which the subject moves fast can be shot at a high frame rate, and moving image data to be recorded Only a specific shooting scene can be slowly played back after shooting without increasing the amount.

  Further, in Patent Document 1 below, when changing the frame rate during moving image shooting, for example, the aperture value is determined with priority over the shutter speed and gain, and then the shutter speed and gain are set according to the determined aperture value. The technology is described. According to such a technique, it is possible to reduce a change in image brightness between frames that occurs before and after the frame rate is changed.

JP 2009-141834 A

  By the way, when switching the frame rate during moving image shooting, a time lag occurs in switching of the driving speed of the image sensor, and an image in the meantime is lost. In order to avoid this, when switching to a high frame rate is possible during movie shooting, the image sensor is always driven at a high frame rate, and during shooting at a low frame rate. In this case, only the image of the frame corresponding to the frame rate may be extracted and recorded.

  However, when the image sensor is always driven at a high frame rate, the maximum exposure time due to the adjustment of the shutter speed is limited. Therefore, in order to obtain an appropriate exposure, the imaging sensitivity, that is, the gain of the output signal of the image sensor is required. There is a problem that the noise of the recorded image increases because it is necessary to always raise it.

The present invention has been made in view of such conventional problems, and an object thereof is to provide an imaging apparatus capable of improving the quality of a moving image during moving image shooting, and a control method and program thereof. .

In order to solve the above-described problem, in the present invention, an imaging frame rate that can be set in the imaging unit is a first frame rate, and an image captured by the imaging unit at an imaging frame rate of the first frame rate is When the imaging sensitivity in the imaging operation of the imaging unit when recording at the same recording frame rate as the first frame rate is the first sensitivity, the image captured by the imaging unit at the first frame rate The number of combined frames when combining and recording at a second frame rate that is slower than the first frame rate and the imaging sensitivity in the imaging operation of the imaging means are: frame combined number = first frame rate / second frame rate. Control means for controlling: imaging sensitivity = first sensitivity / number of frames combined;

According to the present invention, it is possible to improve the quality of a moving image during moving image shooting.

It is a block diagram of a digital camera exemplified as an imaging apparatus of the present invention. It is a figure which shows the operation | movement content of the digital camera 1 in the case of using a recording frame rate switching function. It is a schematic diagram which shows the sequential synthesis | combination of a frame image in case an imaging frame rate is 120 fps. It is a schematic diagram which shows the overlapping synthesis | combination of a frame image in case an imaging frame rate is 60 fps. It is a flowchart which shows the processing content in the moving image shooting mode using a recording frame rate switching function.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a block diagram showing a schematic configuration of a digital camera 1 exemplified as an imaging apparatus of the present invention. The digital camera 1 has a still image shooting mode and a moving image shooting mode as shooting modes.

  The digital camera 1 has a lens block 2 and an image sensor 3. The lens block 2 includes a lens group including a focus lens, an aperture, a lens motor that drives the lens group, and an actuator that drives the aperture to open and close. The lens motor and the actuator are driven by the optical system drive unit 4 based on a command from a CPU (Central Processing Unit) 8, thereby adjusting the focal position and the amount of light received by the image sensor 3.

  The image pickup device 3 is a CCD (Charge Coupled Device) or CMOS (Complementary Meta 10xide Semiconductor) sensor, and is driven by a drive circuit 5 to photoelectrically convert an optical image of a subject, and an electric signal corresponding to the converted optical image, that is, The imaging signal is output to an AFE (Analog Front End) 6.

  The drive circuit 5 can drive the image sensor 3 in a plurality of drive modes based on a command from the CPU 8, and more specifically, a frame rate when driving the image sensor 3 (hereinafter referred to as an image capture frame rate). Can be driven in three drive modes: a high speed mode of 120 fps, a medium speed mode of 60 fps, and a low speed mode of 30 fps. The low speed mode is used in a shooting standby state in the still image shooting mode and the moving image shooting mode, and the medium speed mode and the high speed mode are modes used in moving image shooting in the moving image shooting mode.

  The AFE 6 includes a CDS (Correlated Double Sampling) circuit, a PGA (Programmable Gain Amp), an ADC (Analog-to-Digital Converter), and the like. The AFE 6 performs predetermined analog processing including gain adjustment of the imaging signal output from the imaging device 3, converts the imaging signal after analog processing into a digital signal, and then outputs the converted image data to the image processing unit 7. .

  The gain adjustment of the imaging signal in the AFE 6 is performed based on a command from the CPU 8 in accordance with the ISO sensitivity (imaging sensitivity) set at the time of shooting.

  The image processing unit 7 includes a memory 7 a that temporarily records pixel data after gain adjustment input from the AFE 6. The memory 7a has a memory capacity capable of storing pixel data for a plurality of frames.

  The image processing unit 7 performs various image processes for image recording on the image data temporarily stored in the memory 7a. Image processing performed by the image processing unit 7 includes gamma correction, white balance adjustment, generation of R, G, and B color component data for each pixel, YUV conversion that generates YUV data from the generated RGB data, and the like. Then, the image processing unit 7 supplies the generated YUV data for one frame to the CPU 8 while in the shooting standby state, and supplies it to the CODEC (Coder & Decoder) 9 during shooting. .

  Further, at the time of moving image shooting, the image processing unit 7 also performs a process of synthesizing (adding) image data for a plurality of frames temporarily stored in the memory 7a as described later.

  The YUV data supplied to the CPU 8 in the shooting standby state is supplied to the display unit 10 and displayed as a live view image on the display unit 10. The display unit 10 includes a liquid crystal display that displays a live view image and the like, a drive circuit that drives the liquid crystal display, and the like.

  The CODEC 9 encodes image data (YUV data) supplied from the image processing unit 7 at the time of shooting, and decodes any encoded image data. Although not shown, the CODEC 9 is an orthogonal transformation circuit, a quantization circuit, a motion detection circuit, a forward prediction circuit, an encoding circuit, a decoding circuit, an inverse orthogonal transformation circuit, for encoding and decoding image data, It consists of a frame memory.

  YUV data output from the image processing unit 7 to the CODEC 9 at the time of shooting is compressed and encoded by a JPEG (Joint Photographic Expert Group) method or the like at the time of shooting in the still image mode, and then recorded in the image memory 11 as a still image file. When shooting in the moving image mode, after being compressed and encoded for each frame by the MPEG (Motion Picture Experts Group) method or the like, it is sequentially sent to the image memory 11 and finally recorded as a moving image file.

  In addition, the CODEC 9 decodes the still image or moving image data (encoded data) read from the image memory 11 by the CPU 8 in the reproduction mode, and outputs it to the CPU 8. The decoded data is reproduced on the display unit 10 as a still image or a moving image. The image memory 11 is, for example, a flash memory built in the camera body or various memory cards that are detachable from the camera body.

  In addition, an operation unit 12, a RAM (Random Access memory) 13, and a program memory 14 are connected to the CPU 8. A RAM 13 is a working memory of the CPU 8.

  The operation unit 12 sets a power switch, a shutter key, a mode switching key for switching between a shooting mode which is a basic operation mode of the digital camera 1 and a playback mode for displaying a recorded image, and setting of a lower mode of the shooting mode. And a plurality of keys (not shown) such as a MENU key and a direction key used for various setting operations. Each key in the operation unit 12 is scanned for an operation state by the CPU 8 at any time.

  The shutter key has a so-called half shutter function capable of two-stage operation including a half-press operation and a full-press operation. The half-press operation of the shutter key is used for an instruction to start an AE (Auto Exposure) operation and an AF (Auto Focus) operation, and the full press of the shutter key is used for an imaging instruction.

  The program memory 14 is a flash memory that is, for example, an EEPROM (Electric Erasable Programmable Read Only Memory) in which stored data can be rewritten. The program memory 14 stores a control program for causing the CPU 8 to control the entire operation of the digital camera 1 and various data.

  The control program includes a program for causing the CPU 8 to perform AE control, AF control, and AWB (Auto white balance) control, and a program for causing the CPU 8 to perform processing described later in the moving image shooting mode.

  The various data includes control data constituting a program diagram showing combinations of aperture values and shutter speeds corresponding to appropriate exposure values at the time of shooting. There are a program diagram used for still image shooting and a plurality of program diagrams for each drive mode of the image sensor 3 (for high speed mode, medium speed mode, and low speed mode).

  In the digital camera 1 having the above-described configuration, a recording frame rate that enables a frame rate of a moving image to be recorded (hereinafter referred to as a recording frame rate) to be appropriately switched in a state where an imaging frame rate is fixed in moving image shooting. A switching function is provided.

  This recording frame rate switching function makes it possible to set the recording frame rate to a high speed for specific shooting scenes where the movement of the subject is fast during video recording, and to set the recording frame rate to a low speed for other scenes. Is. That is, the recording frame rate switching function is intended to enable slow reproduction of only a specific shooting scene with a high-quality moving image after shooting while suppressing the data amount of the moving image to be recorded.

  In the digital camera 1, a frame rate (hereinafter referred to as a reproduction frame rate) when reproducing a recorded moving image is fixed to 30 fps regardless of the recording frame rate.

  FIG. 2 is a diagram showing the operation contents of the digital camera 1 when the recording frame rate switching function is used. As shown in FIG. 2, when the recording frame rate switching function is used, the imaging frame rate is set to either 120 fps or 60 fps.

  The recording frame rate that can be specified by the user is a frame rate within the range of the imaging frame rate. That is, when the imaging frame rate is 120 fps, any of 120 fps, 60 fps, and 30 fps can be specified, and when the imaging frame rate is 60 fps, 60 fps or 30 fps can be specified.

  When the recording frame rate switching function is used, the ISO sensitivity is fixed to a value corresponding to the recording frame rate. That is, the ISO sensitivity when the recording frame rate is 120 fps is fixed to 800, the ISO sensitivity when the recording frame rate is 60 fps is 400, and the ISO sensitivity when the recording frame rate is 30 fps is fixed to 200, respectively.

  When the recording frame rate switching function is used, the images of the frames captured at the above-described imaging frame rate are combined by the number of frames corresponding to the recording frame rate, and the combined images form a moving image. Recorded as a frame image. In the following description, a frame image captured at an imaging frame rate is referred to as a captured frame image, and a frame image constituting a moving image is referred to as a recording frame image to distinguish between them.

  The number of captured frame images (the number of frames combined) is 2 (2 frames) when the recording frame rate is 60 fps, and 4 (4 frames) when the recording frame rate is 30 fps. However, when both the imaging frame rate and the recording frame rate are 120 fps, the imaging frame image is used as it is as the recording frame image.

  Furthermore, there are two types of methods for synthesizing the captured frame image. The synthesis method when the imaging frame rate is 120 fps is sequential synthesis, and the synthesis method when the imaging frame rate is 60 fps is overlap synthesis. The synthesis method will be specifically described as follows.

  FIG. 3 is a schematic diagram showing sequential synthesis when the imaging frame rate is 120 fps. As shown in FIG. 5A, when the recording frame rate is 60 fps, the captured frame image is synthesized every two frames.

  Also, as shown in FIG. 5B, when the recording frame rate is 30 fps, the captured frame image is synthesized every four frames.

  FIG. 4 is a schematic diagram showing overlap synthesis when the imaging frame rate is 60 fps. As shown in FIG. 5A, when the recording frame rate is 60 fps, the captured frame image of the frame and the captured frame image of the previous frame are combined for each frame of the captured frame. That is, a part of the captured frame images is used redundantly for generating successive recording frame images.

  Also, as shown in FIG. 5B, when the recording frame rate is 30 fps, the captured frame image of the frame and the captured frame image for the previous three frames are synthesized for every two frames of the captured frame. That is, in this case as well, some of the captured frame images are used redundantly to generate successive recording frame images.

  The processing contents of the CPU 8 in the moving image shooting mode using the recording frame rate switching function will be described below with reference to the flowchart of FIG.

  That is, the CPU 8 starts the operation together with the setting of the moving image shooting mode, immediately sets the drive mode of the image sensor 3 to the low speed mode (30 fps) and starts imaging (step S1), and displays the live view image on the display unit 10. Is started (step S2). Note that while the live view image is displayed, AE control using the above-described program diagram for the low-speed mode is performed.

  While the live view image is being displayed, the CPU 8 sequentially confirms whether there is an instruction to end the moving image shooting mode (such as an instruction to change to the still image shooting mode) by the user, and if there is an instruction to end the moving image shooting mode (step S3: YES). ), And all processes are terminated at that time.

  Further, the CPU 8 sequentially confirms whether or not there is a shooting start instruction by the user while the live view image is displayed. If there is a shooting start instruction (step S4: YES), the CPU 8 temporarily stores it in the memory 7a of the image processing unit 7 immediately before that. Based on the obtained image data, an LV value indicating the current brightness of the subject is acquired (step S5). Note that this LV value may be acquired based on the output signal of the photometric sensor, for example, when the digital camera 1 is provided with a photometric sensor that detects the amount of light.

  Thereafter, the CPU 8 confirms whether or not the LV value is equal to or greater than a predetermined threshold (step S6). The threshold value is a value with which it is possible to determine that a certain level of brightness can be secured in the captured frame image when the image sensor 3 is driven in the high-speed mode (120 fps).

  If the LV value is equal to or greater than the threshold (step S6: YES), the CPU 8 sets the drive mode of the image sensor 3 in the drive circuit 5 to the high speed mode (120 fps) (step S7). Thereafter, the CPU 8 sets the recording frame rate to the initial setting value of 30 fps, that is, the same as the reproduction frame rate, and starts moving image recording by the above-described sequential synthesis (step S8).

  In step S8, the CPU 8 sets the gain in the AFE 6 to a value corresponding to the ISO sensitivity 200, and performs AE control using the program diagram for the high-speed mode during moving image recording.

  That is, the CPU 8 causes the image processing unit 7 to start a process of generating a recording frame image by synthesizing the captured frame images captured with the ISO sensitivity 200 every four frames as illustrated in FIG. Processing for compressing the generated recording frame image in the CODEC 9 and recording it in the image memory 11 is started.

  If the LV value is less than the threshold value (step S6: NO), the CPU 8 sets the drive mode of the image sensor 3 in the drive circuit 5 to the medium speed mode (60 fps) (step S9). As a result, the brightness of the captured image of each frame can be ensured twice as bright as when the image sensor 3 is driven in the high speed mode. Thereafter, the CPU 8 also sets the recording frame rate to 30 fps, which is the initial setting value, and starts moving image recording by the above-described overlap synthesis (step S10).

  In step S10, the CPU 8 sets the gain in the AFE 6 to a value corresponding to the ISO sensitivity 200, and performs AE control using the program diagram for the medium speed mode during moving image recording.

  That is, as shown in FIG. 4B, the CPU 8 causes the image processing unit 7 to capture the captured frame image of the frame and the captured frames of the immediately preceding three frames for every two frames captured at the ISO sensitivity 200. A process of generating a recording frame image by combining the image is started, and a process of compressing the generated recording frame image in the CODEC 9 and recording it in the image memory 11 is started.

  Thereafter, while the image pickup device 3 is driven in the high-speed mode or the medium-speed mode and the moving image shooting is performed, the CPU 8 does not instruct to change the recording frame rate by the user (step S11: NO) and does not instruct the shooting end. If this is the case (step S13: NO), the moving image recording process with the setting contents described above started in step S8 or step S10 is continued.

  If the user gives an instruction to change the recording frame rate during moving image recording (step S11: YES), the CPU 8 changes the recording frame rate in accordance with the instruction from the user, and changes the ISO sensitivity and the added number of sheets. The value is changed to a predetermined value (see FIG. 2) according to the later recording frame rate and the driving mode of the image sensor 3 at that time, that is, the imaging frame rate (step S12).

  Thus, for example, when the imaging frame rate is 120 fps, when the user changes the recording frame rate from 30 fps to 120 fps, as shown in FIG. 3B, the ISO sensitivity is 800 and the number of added sheets is one. The moving image recording process is continued with the state changed to (= no addition).

  When the user changes the recording frame rate from 30 fps to 60 fps, the moving image recording process is continued with the ISO sensitivity being changed to 400 and the added number being changed to 2 (see FIG. 3A).

  Further, when the recording frame rate is changed from 120 fps or 60 fps to 30 fps at the initial setting, the moving image recording process is continued again with the ISO sensitivity set to 200 and the added number set to 4 (FIG. 3B). )reference).

  On the other hand, unlike the above, for example, when the imaging frame rate is 60 fps, when the user changes the recording frame rate from 30 fps to 60 fps, the ISO sensitivity is 400, as shown in FIG. The moving image recording process is continued with the number of sheets changed to two.

  Furthermore, after the recording frame rate is changed to 60 fps, when the recording frame rate is changed to 30 fps at the initial setting by the user at any time, the ISO sensitivity is changed to 200 and the number of added sheets is changed to 4 again. In this state, the moving image recording process is continued (see FIG. 4B).

  As described above, even when the recording frame rate is changed according to the user's instruction, the CPU 8 generates and records the recording frame image at the recording frame rate according to the user's instruction without changing the imaging frame rate. .

  At the same time, by adjusting the ISO sensitivity and the number of combined frame images, when the shooting frame rate is 120 fps, each recording frame image always has the same brightness as when the recording frame rate is 120 fps and the ISO sensitivity is 800. In addition, when the imaging frame rate is 60 fps, the same brightness as that when the recording frame rate is 60 fps and the ISO sensitivity is 400 is always secured in each recording frame image.

  If the user instructs to end the shooting while the moving image recording process described above is repeated (step S13: YES), the CPU 8 ends the moving image recording at that time (step S14), and then The drive mode is set (changed) to the low speed mode (30 fps) (step S15). That is, the imaging frame rate is reduced to the extent that a live view image can be displayed, thereby preventing unnecessary power consumption.

  Thereafter, the CPU 8 returns to the process of step S3, and repeatedly executes the processes after step S4 described above until the user gives an instruction to end the moving image shooting mode (step S3: NO).

  As described above, in the moving image shooting mode using the recording frame rate switching function, since the imaging frame rate during moving image shooting is fixed to 120 fps or 60 fps regardless of the recording frame rate, the recording frame rate is changed during moving image shooting. However, no time lag occurs in the imaging operation.

  In addition, when the recording frame rate is set to be lower than the imaging frame rate, the recording frame image is generated by synthesizing the imaging frame images corresponding to the number of frames according to the recording frame rate, so that the recording frame rate is substantially fixed. Exposure time can be increased. In addition, random noise present in a plurality of captured frame images to be combined does not increase in the combined image.

  At the same time, by setting the ISO sensitivity to a value corresponding to the recording frame rate and lower than that when the recording frame rate is the same as the imaging frame rate, the noise of the recording frame image can be reduced and the recording frame rate can be reduced. The brightness of the image before and after the change can be kept constant.

  Therefore, even when the recording frame rate can be switched during moving image shooting, a higher quality moving image can be recorded.

  Also, the imaging frame rate during moving image shooting is set according to the brightness (LV value) of the subject at the start of shooting, and when the brightness of the subject is less than the threshold, the fastest possible imaging The frame rate is set to 60 fps, which is lower than 120 fps. That is, the brightness of the captured image of each frame can be ensured twice as bright as when the image sensor 3 is driven in the high speed mode.

  Therefore, it is possible to shoot a darker subject when the recording frame rate switching function is used as compared with the case where the imaging frame rate is always fixed to 120 fps. That is, the use range of the recording frame rate switching function at the time of moving image shooting can be expanded.

  Also, the method for synthesizing the captured frame image while the recording frame rate is set to be lower than the imaging frame rate is the above-described sequential composition when the imaging frame rate is fixed to 120 fps, and the imaging frame rate is fixed to 60 fps. When this is done, the above-described overlap synthesis was adopted.

  Therefore, regardless of the imaging frame rate, when the recording frame rate is the same, the ISO sensitivity can be the same (see FIG. 2), and the imaging frame rate is fixed to a different value according to the brightness of the subject. In addition, the amount of noise corresponding to the ISO sensitivity that inevitably occurs in the recording frame image can be made comparable.

  Therefore, when the recording frame rate is the same, the quality of the moving image to be recorded can be stabilized regardless of the brightness of the subject.

  In the present embodiment, the case where the fastest imaging frame rate that can be set is 120 fps and the recording frame rate that can be changed (set) during moving image shooting is three stages of 120 fps, 60 fps, and 30 fps has been described. .

  However, when the present invention is implemented, the fastest imaging frame rate that can be set may be 120 fps or more. Further, the recording frame rate that can be changed (set) during moving image shooting only needs to be lower than the fastest imaging frame rate, and the recording frame rate may be three or more stages.

  In addition, the recording frame rate that can be changed (set) does not necessarily have to be 1 / n (n is an integer) of the fastest imaging frame rate that can be set. In other cases, the ISO sensitivity can be used as the imaging frame rate. By fixing the value to a predetermined value according to the ratio to the recording frame rate, a higher quality moving image can be recorded.

  In this embodiment, the recording frame rate is switched according to the change instruction from the user during moving image shooting. However, when the present invention is implemented, the recording frame rate is automatically switched at a predetermined timing. You may make it carry out automatically.

  More specifically, for example, the recording frame rate is changed from a recording frame rate (30 fps) that is the same as the playback frame rate at a timing when a predetermined time such as a time set in advance by the user has elapsed after the start of moving image shooting. You may make it switch automatically to a high-speed recording frame rate (the fastest recording frame rate etc. which can be set).

  In this case, for example, it is convenient when the user shoots a golf swing form with the digital camera 1 fixed on a tripod or the like. In other words, if the user sets the required time from the start of shooting operation to the start of the golf swing within the angle of view as the predetermined time, the fastest recording frame can be obtained only during the golf swing. You can shoot at a rate. That is, it is possible to perform slow reproduction with a high-quality moving image only while performing a golf swing while reducing the amount of moving image data recorded until the golf swing is started.

  In addition to the above, the shooting time at the fastest recording frame rate is also set to a predetermined time such as a time preset by the user, and the recording frame rate is automatically switched (returned) to 30 fps when the predetermined time has elapsed. May be. In that case, the amount of moving image data recorded from the end of the golf swing to the end of moving image shooting can also be reduced.

  Also, for example, during moving image shooting, in parallel with recording of moving images, moving object detection is performed to detect a specific movement of the subject using a known image recognition technique based on the captured frame image, and the specific movement is detected. The recording frame rate may be automatically switched to the fastest recording frame rate at the timing.

  Further, after the recording frame rate is switched to the fastest recording frame rate as described above, the recording frame rate is automatically switched (returned) to 30 fps when a specific movement of the subject can be detected. Good.

  In that case, for example, during movie shooting, in parallel with the recording of the moving image, the golf swing start time (for example, the back swing start time) by an arbitrary person based on the captured frame image, and the golf swing end time By detecting (for example, when the follow-through is completed), it is possible to shoot at the fastest recording frame rate only while performing a golf swing accurately.

  In addition to the above example, the switching of the recording frame rate during moving image shooting may be performed automatically at the timing when the angle of view suddenly changes with panning, for example. In this case, in addition to the time when the angle of view starts to change suddenly, the time when the angle of view becomes stable is also detected, and the recording frame rate is automatically switched (returned) to 30 fps at that point. Good.

  The detection of the time when the angle of view suddenly changes or the time when the angle of view is stable can be detected based on the captured frame image using a known image recognition technique, and an acceleration sensor is provided in the camera body. Then, it can be performed by the detection signal of the acceleration sensor.

  In that case, for example, when the main subject starts moving during video recording and the camera is panned accordingly, the recording frame rate can be automatically switched to the fastest recording frame rate. The main subject during panning and the change state of all subjects including the background can be slowly reproduced with a high-quality moving image.

As mentioned above, although embodiment of this invention and its modification were demonstrated, as long as these are in the range with which the effect of this invention is obtained, it can change suitably, and embodiment after change is also in a claim. It is included in the scope of the invention described and equivalent invention. The invention described in the scope of the claims of the present application will be appended below.
[Claim 1]
Imaging means for capturing an image of a subject;
Combining means for combining a plurality of images picked up by the image pickup means at a predetermined image pickup frame rate;
A recording unit that records an image captured by the imaging unit or an image combined by the combining unit at a predetermined recording frame rate;
Imaging control means for causing the imaging means to start an imaging operation in a state in which an imaging frame rate is fixed to the predetermined imaging frame rate;
Changing means for changing the predetermined recording frame rate within a range up to the predetermined imaging frame rate during an imaging operation period at the predetermined imaging frame rate in the imaging means;
When the recording frame rate changed by the changing unit matches the predetermined imaging frame rate, the image stored in the recording unit is changed to an image taken by the imaging unit, and after the change by the changing unit When the recording frame rate is less than the predetermined imaging frame rate, the synthesizing unit starts synthesizing the plurality of images, and the image stored by the recording unit is combined with the synthesizing unit. Recording control means to be changed to,
An imaging apparatus comprising: sensitivity control means for controlling imaging sensitivity in an imaging operation of the imaging means according to the changed recording frame rate in accordance with the change of the recording frame rate by the changing means.
[Claim 2]
When the changed recording frame rate is less than the predetermined imaging frame rate, the recording control unit causes the combining unit to respond to a ratio between the predetermined imaging frame rate and the changed recording frame rate. The imaging apparatus according to claim 1, wherein synthesis of a plurality of images corresponding to a predetermined number is started.
[Claim 3]
The sensitivity control unit fixes the imaging sensitivity to an imaging sensitivity determined according to a ratio between the predetermined imaging frame rate and the changed recording frame rate. The imaging device described.
[Claim 4]
An acquisition unit for acquiring the brightness of the subject at the start of the imaging operation in the imaging unit;
The imaging control unit sets an imaging frame rate according to the brightness of the subject acquired by the acquisition unit as the predetermined imaging frame rate, and the imaging frame rate is fixed to the set imaging frame rate. The image pickup apparatus according to claim 1, wherein the image pickup operation is started by the means.
[Claim 5]
The imaging control unit sets the fastest imaging frame rate that can be set as the predetermined imaging frame rate when the brightness of the subject acquired by the acquisition unit is greater than or equal to a threshold, and the subject acquired by the acquisition unit The imaging apparatus according to claim 4, wherein when the brightness of the camera is equal to or greater than a threshold, an imaging frame rate that is ½ of the fastest imaging frame rate is set as the predetermined imaging frame rate.
[Claim 6]
The recording control means, when the recording frame rate after the change by the changing means is less than the predetermined imaging frame rate, when causing the synthesizing means to start synthesizing the plurality of images,
When the predetermined imaging frame rate set by the imaging control means is the fastest imaging frame rate, the synthesizing unit sequentially combines different images for each recording frame. Start,
When the predetermined imaging frame rate set by the imaging control means is an imaging frame rate that is one half of the fastest imaging frame rate, a plurality of images to be synthesized for each recording frame are sent to the synthesizing means. The imaging apparatus according to claim 4, wherein overlap synthesis is started in which one or a plurality of images used in the previous recording frame is included in the first image.
[Claim 7]
7. The change unit according to claim 1, wherein the changing unit changes the predetermined recording frame rate in response to a user request during an imaging operation period at the predetermined imaging frame rate in the imaging unit. The imaging apparatus of Claim 1.
[Claim 8]
7. The change unit according to claim 1, wherein the changing unit automatically changes the predetermined recording frame rate at a predetermined timing during an imaging operation period at the predetermined imaging frame rate in the imaging unit. The imaging device according to any one of the above.
[Claim 9]
An imaging unit that captures an image of a subject, a combining unit that combines a plurality of images captured by the imaging unit at a predetermined imaging frame rate, and an image captured by the imaging unit or an image that has been combined by the combining unit. A control method for an imaging apparatus comprising recording means for recording at a predetermined recording frame rate,
A step of causing the imaging means to start an imaging operation in a state where an imaging frame rate is fixed to the predetermined imaging frame rate;
Changing the predetermined recording frame rate within a range up to the predetermined imaging frame rate during an imaging operation period at the predetermined imaging frame rate in the imaging means;
When the changed recording frame rate matches the predetermined imaging frame rate, the image stored by the recording unit is changed to an image captured by the imaging unit, and the changed recording frame rate is the predetermined imaging frame rate. When the image capturing frame rate is less than the imaging frame rate, the combining unit starts combining the plurality of images, and the image stored in the recording unit is changed to an image combined by the combining unit;
A method of controlling an imaging sensitivity in an imaging operation of the imaging unit according to the change in the recording frame rate, in accordance with the recording frame rate after the change.
[Claim 10]
An imaging unit that captures an image of a subject, a combining unit that combines a plurality of images captured by the imaging unit at a predetermined imaging frame rate, and an image captured by the imaging unit or an image that has been combined by the combining unit. A computer having an imaging device including a recording unit configured to record at a predetermined recording frame rate;
Imaging control means for causing the imaging means to start an imaging operation in a state in which an imaging frame rate is fixed to the predetermined imaging frame rate;
Changing means for changing the predetermined recording frame rate within a range up to the predetermined imaging frame rate during an imaging operation period at the predetermined imaging frame rate in the imaging means;
When the recording frame rate changed by the changing unit matches the predetermined imaging frame rate, the image stored in the recording unit is changed to an image taken by the imaging unit, and after the change by the changing unit When the recording frame rate is less than the predetermined imaging frame rate, the synthesizing unit starts synthesizing the plurality of images, and the image stored by the recording unit is combined with the synthesizing unit. Recording control means to be changed to,
A program that functions as sensitivity control means for controlling the imaging sensitivity of the imaging operation of the imaging means in accordance with the changed recording frame rate in accordance with the change of the recording frame rate by the changing means.

DESCRIPTION OF SYMBOLS 1 Digital camera 2 Lens block 3 Image pick-up element 4 Optical system drive part 5 Drive circuit 6 AFE
7 Image processing unit 7a Memory 8 CPU
9 CODEC
DESCRIPTION OF SYMBOLS 10 Display part 11 Image memory 12 Operation part 13 RAM
14 Program memory

Claims (7)

The imaging frame rate that can be set in the imaging means is a first frame rate,
The imaging sensitivity in the imaging operation of the imaging unit when the imaging unit records the image captured at the imaging frame rate of the first frame rate at the same recording frame rate as the first frame rate is the first sensitivity. When,
The number of frame synthesis when the image captured by the imaging unit is combined and recorded at a second frame rate lower than the first frame rate and the imaging sensitivity in the imaging operation of the imaging unit.
Frame synthesis number = first frame rate / second frame rate;
Imaging sensitivity = first sensitivity ÷ number of frames combined;
Control means to control as,
An imaging apparatus comprising: The control means includes
When the first frame rate is higher than a predetermined frame rate,
All of the multiple images to be combined for frame synthesis are sequentially combined differently for each recording frame,
When the first frame rate is equal to or lower than a predetermined frame rate,
Performing overlapping composition in which one or a plurality of images used in the previous recording frame are included in a plurality of images to be combined for frame composition;
The imaging apparatus according to claim 1. The imaging apparatus according to claim 1, further comprising a changing unit that changes the second frame rate during an imaging operation period at the first frame rate in the imaging unit. 4. The imaging apparatus according to claim 3 , wherein the changing unit changes the second frame rate according to a user's request during an imaging operation period at the first frame rate in the imaging unit. . The imaging unit according to claim 3 , wherein the changing unit automatically changes the second frame rate at a predetermined timing during an imaging operation period at the first frame rate in the imaging unit. apparatus. A method for controlling an imaging apparatus including an imaging means ,
The fastest imaging frame rate that can be set in the imaging means is the first frame rate,
The imaging sensitivity in the imaging operation of the imaging unit when the imaging unit records the image captured at the imaging frame rate of the first frame rate at the same recording frame rate as the first frame rate is the first sensitivity. When,
The number of frame synthesis when the image captured by the imaging unit is combined and recorded at a second frame rate lower than the first frame rate and the imaging sensitivity in the imaging operation of the imaging unit.
Frame synthesis number = first frame rate / second frame rate;
Imaging sensitivity = first sensitivity ÷ number of frames combined;
As a controlling process,
A method for controlling an imaging apparatus, comprising: A computer included in an imaging apparatus provided with imaging means ,
The fastest imaging frame rate that can be set in the imaging means is the first frame rate,
The imaging sensitivity in the imaging operation of the imaging unit when the imaging unit records the image captured at the imaging frame rate of the first frame rate at the same recording frame rate as the first frame rate is the first sensitivity. When,
The number of frame synthesis when the image captured by the imaging unit is combined and recorded at a second frame rate lower than the first frame rate and the imaging sensitivity in the imaging operation of the imaging unit.
Frame synthesis number = first frame rate / second frame rate;
Imaging sensitivity = first sensitivity ÷ number of frames combined;
Control means to control as,
A program characterized by making it function.

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