JP2004187018A - Method and device for photographing moving picture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for photographing moving pictures which allow a recording frame rate to be always changed and set at a proper timing. <P>SOLUTION: In moving picture recording of consecutively picking up images of a subject and making picked-up images into frame pictures, a preceding image is kept undeleted after the second or following image is picked up (YES in SA2), and a current image and the preceding image stored in a buffer memory are compared with each other, and recording operation is skipped to delete the current image in the case of a small difference between them (SA3 to SA6). In the case that the preceding image has been deleted or a difference between the current image and the preceding image is large (NO in SA3 or SA5), the current image is recorded in a preservation memory (SA7). As a result, the recording frame rate can be changed on the basis of variation images in the same time interval, and the proper recording frame rate is always set. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a moving image photographing apparatus and a moving image photographing method suitable for use in an electronic still camera or the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a digital camera having a moving image shooting function, a motion-jpeg method for compressing a moving image in units of still images is often used. When shooting a moving image, images are recorded at a fixed frame rate, for example, 15 frames per second. Have been.
[0003]
In addition, Japanese Patent Application Laid-Open No. H11-163873 discloses an image (hereinafter, referred to as a frame image) that is continuously imaged in accordance with the speed of the object and the brightness of the image for the purpose of always accurately imaging the object irrespective of the state of the object. A digital camera that changes the imaging interval (frame rate) is described.
[0004]
[Patent Document 1]
JP 2001-358984 A (see paragraph "0050")
[0005]
[Problems to be solved by the invention]
However, in order to efficiently shoot a moving image with a smaller number of images, as described above, the frame rate of the image to be captured (imaging frame) according to a change in the subject speed or brightness of the image, that is, a change in the subject (image). In the case where it is attempted to save the number of images by changing the recording interval (recording frame rate) by changing the rate), the following problem arises.
[0006]
That is, since the imaging interval of the frame image is different between when the imaging frame rate is normal and when the imaging frame rate is high, even if the degree of change of the subject imaged immediately before and after is exactly the same, the standard frame rate and the high frame rate And the result of the comparison by the image comparison changes. For this reason, a blurring occurs in the determination result, so that it is not possible to perform an appropriate switching of the recording frame rate during shooting, and as a result, a change between successive frame images is different from that at other times. It becomes large (small), and the recorded moving image itself becomes unnatural. In addition, there is a problem that natural moving images cannot be reproduced even if the reproduction frame rate for displaying each image continuously during reproduction is adjusted.
[0007]
The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a moving image photographing apparatus and a moving image photographing method that can always change and set a recording frame rate at appropriate timing.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is directed to a moving image photographing apparatus that continuously captures an image of a subject by an imaging unit and records a moving image having the captured image as a frame image in a recording unit. Detecting a degree of change of an image within the same time interval in an image continuously captured by the imaging unit, and controlling an imaging time interval of each image to be recorded in the recording unit as a frame image based on the detection result. And control means for performing the control.
[0009]
In such a configuration, during moving image shooting, the imaging time interval of each image recorded as a frame image is controlled based on the degree of change of the image within the same time interval at each time point, that is, the degree of change based on the same time reference. Therefore, when the recording frame rate is changed in accordance with the change of the subject, the recording frame rate can always be changed and set at an appropriate timing.
[0010]
Further, in the invention according to claim 2, the control unit compares a previous image and a current image of a subject captured by an imaging operation at the same time interval by the imaging unit, and compares the two images. Detecting means for detecting the degree of change; determining means for determining whether or not the current image can be recorded on the recording means based on the detection result of the detecting means; Recording control means for causing the recording means to record only the image as a frame image.
[0011]
In such a configuration, the interval of the imaging operation, that is, the imaging frame rate is made constant (fixed), the degree of change between successive frame images obtained sequentially is detected, and whether or not each frame image can be recorded is determined according to the detection result. It is determined. That is, the recording of the captured image is thinned out based on the degree of change of the image within the same time interval, and as a result, the recording frame rate is changed. Therefore, when the recording frame rate is changed according to the change of the subject, the recording frame rate can always be changed and set at an appropriate timing.
[0012]
Further, in the invention according to claim 3, the recording control unit, when the previous image is not recorded in the recording unit, regardless of the determination result of the determination unit, the current image is a frame image Is stored in the recording means.
[0013]
With such a configuration, it is possible to prevent the recorded images from being thinned out more than necessary in a state where the degree of change between the frame images sequentially detected during photographing is continuously small.
[0014]
In the invention according to claim 4, the control unit compares a previous image captured by the imaging unit with a current image, and detects a degree of change between the two images, Determining means for determining whether or not the imaging interval of the image can be changed by the imaging means based on the detection result of the detection means; and determining that the imaging interval should be changed by the determination means, An imaging interval changing unit that changes an imaging interval, and a criterion changing unit that changes a criterion for determining whether or not the imaging interval can be changed in the determining unit to a criterion corresponding to the changed imaging interval by the imaging interval changing unit. Was included.
[0015]
In such a configuration, the recording frame rate is changed by changing the interval of the imaging operation, that is, the imaging frame rate in accordance with the degree of change between the previous image and the current image, and at the same time, the imaging frame rate is changed. The criterion for determining whether or not the criterion is changed to a criterion corresponding to the imaging frame rate at each time point. As a result, the recording frame rate is changed based on the degree of change of the image within the same time interval at each time point, that is, the degree of change based on the same time reference. Therefore, when the recording frame rate is changed according to the change of the subject, the recording frame rate can always be changed and set at an appropriate timing.
[0016]
In the invention according to claim 5, the control unit compares the current image captured by the image capturing unit with a past image captured before the current image, and determines a degree of change between the two images. Detecting means for detecting, based on a detection result of the detecting means, determining means for determining whether or not the imaging interval of the image by the imaging means can be changed, and when it is determined by the determining means to change the imaging interval, An imaging interval changing unit that changes an imaging interval of an image in the imaging unit; and a past image that is compared with a current image when the detecting unit detects a degree of change between the two images. And a comparison image changing means for changing to an image picked up by the image pickup means at a predetermined time according to the image pickup interval after the change by the means.
[0017]
In such a configuration, the recording frame rate is changed by changing the interval of the imaging operation, that is, the imaging frame rate, according to the degree of change between the current image and the previous image captured earlier. Is changed to an image captured at a predetermined time according to the changed recording frame rate. As a result, the recording frame rate is changed based on the degree of change of the image within the same time interval at each time point, that is, the degree of change based on the same time reference. Therefore, when the recording frame rate is changed according to the change of the subject, the recording frame rate can always be changed and set at an appropriate timing.
[0018]
According to a sixth aspect of the present invention, in the moving image photographing method of continuously recording an image of a subject by an imaging unit and recording a moving image in which the captured image is a frame image, Detecting a degree of change of the image within the same time interval in the captured image, and controlling an imaging time interval of each image to be recorded in the recording unit as a frame image based on the detection result. And
[0019]
According to this method, when the recording frame rate is changed according to the change of the subject, the recording frame rate can always be changed and set at an appropriate timing.
[0020]
Further, in the invention according to claim 7, the computer having a moving image photographing apparatus that continuously captures an image of a subject by an imaging unit and records a moving image having the captured image as a frame image in a recording unit, A control for detecting a degree of change of an image within the same time interval in an image continuously captured by the imaging unit, and controlling an imaging time interval of each image recorded in the recording unit as a frame image based on the detection result. It was a program to function as a means.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
[0022]
(First Embodiment)
FIG. 1 is a block diagram showing a schematic configuration of an electronic still camera 1 common to each embodiment of the present invention. The electronic still camera 1 has a moving image photographing function by a motion-jpeg method in addition to a normal still image photographing function, and has a CCD 2 and a DSP / CPU 3 as image pickup means. The DSP / CPU 3 is a one-chip microcomputer that has various digital signal processing functions including compression / expansion processing of image data by the jpeg method and controls each unit of the electronic still camera 1.
[0023]
The DSP / CPU 3 is connected to a TG (Timing Generator) 4 for driving the CCD 2, and the TG 4 is connected to a unit circuit 5 for inputting an analog imaging signal corresponding to an optical image of a subject output from the CCD 2. Have been. The unit circuit 5 includes a CDS (Correlated Double Sampling) circuit that correlatively double-samples and holds an image signal output from the CCD 2 through photoelectric conversion, a gain adjustment amplifier (AGC) that amplifies the image signal, and an amplified image signal. It is composed of an A / D converter (AD) for converting to a digital signal, and the output signal of the CCD 2 is sent to the DSP / CPU 3 as a digital signal via the unit circuit 5.
[0024]
The DSP / CPU 3 is connected to a display device 6 and a key input unit 7, and also connected to a DRAM 9, a built-in flash memory 10 and a card interface 11 via an address / data bus 8. Is connected to a removable memory card 12 mounted on a throttle (not shown) of the main body of the electronic still camera 1.
[0025]
The DRAM 9 is a buffer memory for temporarily storing image data of a subject, which is digitized after being picked up by the CCD 2, and is also used as a working memory of the DSP / CPU 3. In particular, the DRAM 9 is provided with a storage area for storing image data of two images that have been captured by the CCD 2 one after another at the time of capturing a moving image to be described later.
[0026]
The built-in flash memory 10 stores an operation program of the DSP / CPU 3 and various data used for controlling each unit. The DSP / CPU 3 operates according to the operation program to execute the detection means, the judgment means, Functions as recording control means. The memory card 12 is a storage memory (recording means) for recording a file of a still image compressed by the JPEG method and a moving image file by the motion-jpeg method.
[0027]
The display device 6 includes a color LCD and its driving circuit, displays a subject image picked up by the CCD 2 as a through image when in a shooting standby state, and is read from the memory card 12 and expanded when a recorded image is reproduced. Display the recorded image. The key input unit 7 includes a plurality of operation keys such as a shutter button, a power key, and a MENU key, and outputs a key input signal corresponding to a key operation by a user to the DSP / CPU 3.
[0028]
Next, the operation of the electronic still camera 1 having the above configuration at the time of shooting a moving image will be described. FIG. 2 is a flowchart illustrating a procedure of the moving image shooting process of the DSP / CPU 3 when the user presses the shutter button after the moving image shooting mode is set.
[0029]
The DSP / CPU 3 starts processing when the shutter button is pressed, and first transfers an image captured by the CCD 2 to the DRAM 9 and temporarily stores the image (step SA1). Next, if the image stored here is not the second or subsequent image as when the shutter button was pressed (NO in step SA2), the image (frame image) captured this time is stored in the memory card 12 (Step SA7).
[0030]
Subsequently, if the shutter button is pressed (YES in step SA8), the process returns to step SA1 to perform the second imaging. After the second or subsequent imaging is performed (YES in step SA2), first, it is determined whether or not the previously captured image has not been skipped, that is, whether or not the recording of the previously captured image has been skipped. (Step SA3). This determination is made by checking the state of a flag described later. If the images have been thinned out (NO in step SA3), the frame image captured this time is transferred to the memory card 12 and recorded (step SA7).
[0031]
If the previously captured image is not thinned out (YES in step SA3), the previously captured frame image is compared with the currently captured frame image (step SA4). Such a comparison process calculates, for example, overall or partial brightness or luminance distribution for both images by a predetermined procedure, and quantifies the degree of change between both images as a change amount based on both calculation results. This is the acquisition process. If the difference between the current frame image and the previous frame image is large, that is, if the amount of change exceeds a predetermined threshold value (NO in step SA5), the process directly proceeds to step SA7, and the current frame image is taken. Is transferred to the memory card 12 and recorded.
[0032]
On the other hand, when the difference between the current frame image and the previous frame image is small, that is, when the change amount is equal to or smaller than the threshold (YES in step SA5), a flag indicating that the current frame image has been thinned is set ( Step SA6), proceed to step SA8 without recording the current frame image. Therefore, immediately after this, if the shutter button is still pressed (YES in step SA8), the result of the determination in step SA3 is NO, and the next captured image is unconditionally transferred to the memory card 12. Record. Then, while the shutter button is kept pressed, the above-described processing is repeated. When the shutter button is released (NO in step SA8), the moving image shooting processing ends at that point.
[0033]
As described above, in the present embodiment, the imaging frame rate (interval of the imaging operation) is fixed (fixed), and the frame image is thinned out only when the degree of change between the current frame image and the previous frame image is small ( As a result, the recording frame rate can be changed based on the degree of change of the image within the same time interval. Therefore, since an appropriate recording frame rate can always be set, a change between arbitrary consecutive frame images does not become large (small) as compared with other time points, and a moving image that can be reproduced in a natural state. Can be shot with a smaller number of images.
[0034]
In addition, in the present embodiment, when the previous frame image is thinned out, the current frame image is always recorded, so that the degree of change between the frame images sequentially detected during shooting is small. In the case where a small number of states continues continuously, that is, while the movement of the subject is small, it is possible to prevent the recording image from being thinned out more than necessary. Therefore, even in such a case, a moving image that can be reproduced in a more natural state can be captured.
[0035]
In the present embodiment, the frame image is recorded once every two frames when the state in which the change of the frame image is small continues, but the frequency of recording the frame image regardless of the change of the frame image is described. Can be set arbitrarily. For example, a frame image may be recorded once in three frames and twice in three frames.
[0036]
(Second embodiment)
Next, a second embodiment of the present invention will be described. In the present embodiment, unlike the first embodiment, the image capturing frame rate of the image captured by the CCD 2 is set to a high frame rate (20 frames per second) and a low frame rate (20 (10 pictures per second).
[0037]
The hardware configuration of the electronic still camera according to the present embodiment is the same as that shown in FIG. 1, but the built-in flash memory 10 includes the DSP / CPU 3 including the detection unit, the judgment unit, Means and a program for causing it to function as a judgment criterion changing means are stored. Also in the present embodiment, a storage area for storing two pieces of image data taken in succession by the CCD 2 is secured in the DRAM 9 at the time of capturing a moving image.
[0038]
Hereinafter, the operation of the electronic still camera according to the present embodiment will be described with reference to the flowcharts of FIGS. 3 and 4 showing the procedure of the moving image shooting process executed by the DSP / CPU 3 when the user presses the shutter button in the moving image shooting mode. .
[0039]
The DSP / CPU 3 starts processing when the shutter button is pressed, first sets a high frame rate shooting mode (step SB1), and further sets a threshold value of a change amount serving as a criterion for a switching operation of an imaging frame rate described later. The first threshold for the high frame rate shooting mode is set in advance (step SB2). Subsequently, an image pickup process is performed by the CCD 2 (step SB3). When the temporary storage of the frame image output from the CCD 2 in the DRAM 9 is completed (YES in step SB4), the previous frame image stored in the DRAM 9 and the current frame image are stored. Compare with the image (step SB5). Such comparison processing is the same as the processing of step SA4 of the first embodiment, and finally obtains a change amount indicating the degree of change between both images. Next, it is determined whether or not the obtained change amount exceeds a currently set threshold value (first threshold value at the start of moving image shooting), that is, whether or not the change amount is large (step S1). SB6) The following processing is performed according to the determination result.
[0040]
That is, if the amount of change does not exceed the threshold value at that time (NO in step SB6), the shooting mode set at that time is not the high frame rate shooting mode (NO in step SB7). The current frame image captured in step SB3 is transferred to the memory card 12 and recorded (step SB13). Conversely, if the high frame rate shooting mode is set at that time (YES in step SB7), the shooting mode is switched to the low frame rate shooting mode (step SB8), and the low frame rate predetermined as a threshold is further set. After setting the second threshold value for the photographing mode (step SB9), the current frame image is transferred to the memory card 12 and recorded (step SB13). Here, the second threshold value is a value (change amount) larger than the first threshold value, and in the present embodiment, the ratio of the imaging time interval between the high frame rate and the low frame rate is 1: 2. Therefore, a value that is approximately twice the first threshold value is determined accordingly.
[0041]
On the other hand, if the result of the determination in step SB6 is YES and the change amount exceeds the threshold at that time, the shooting mode set at that time must be the low frame rate shooting mode. If it is (NO in step SB10), the current frame image is transferred to the memory card 12 and recorded (step SB13). Conversely, if the low frame rate shooting mode is set at that time (YES in step SB10), the shooting mode is switched to the high frame rate shooting mode (step SB11), and the threshold for the high frame rate shooting mode is set as the threshold. After setting the threshold value of 1 (step SB12), the current frame image is transferred to the memory card 12 and recorded (step SB13).
[0042]
After recording the captured frame image, while the shutter button is kept pressed (YES in step SB14), the next imaging cycle set according to the currently set imaging frame rate arrives. At this point (YES in step SB15), the process returns to step SB3 to perform new imaging, temporarily stores the captured image, and then repeats the above-described processing up to step SB13. Then, when the shutter button is released (NO in step SB14), the moving image photographing process ends at that point.
[0043]
As described above, in the present embodiment, the recording frame rate is changed by changing the imaging frame rate between the high frame rate and the low frame rate in accordance with the degree of change between the previous image and the current image. At the same time, by switching the threshold of the amount of change, which is the criterion for the switching operation of the imaging frame rate, to the first threshold and the second threshold in accordance with the imaging frame rate, as a result, the degree of change based on the same time reference The recording frame rate is changed based on this. Therefore, also in the present embodiment, since an appropriate recording frame rate can always be set, a change between arbitrary consecutive frame images does not become large (small) as compared with other points in time, and natural A video that can be reproduced in a proper state can be shot with a smaller number of images.
[0044]
(Third embodiment)
Next, a third embodiment of the present invention will be described. In the present embodiment, similarly to the second embodiment, the image capturing frame rate of the image captured by the CCD 2 is changed to a high frame rate (20 frames per second) and a low frame rate (20 (10 pictures per second).
[0045]
The hardware configuration of the electronic still camera according to the present embodiment is the same as that shown in FIG. 1, but the built-in flash memory 10 includes the DSP / CPU 3 including the detecting unit, the determining unit, and the imaging unit according to the present invention. A program for functioning as an interval changing unit and a comparison image changing unit is stored. Also, unlike the first and second embodiments, when a moving image is shot, images are sequentially taken by the CCD 2 in the DRAM 2. A storage area for storing three pieces of image data is secured.
[0046]
Hereinafter, the operation of the electronic still camera according to the present embodiment will be described with reference to the flowcharts of FIGS. 5 and 6 showing the procedure of the moving image shooting process executed by the DSP / CPU 3 when the user presses the shutter button in the moving image shooting mode. .
[0047]
The DSP / CPU 3 starts processing when the shutter button is pressed, first sets a high frame rate photographing mode (step SC1), and then performs image pickup processing by the CCD 2 (step SC2). Next, after the temporary storage of the frame image output from the CCD 2 in the DRAM 9 is completed (YES in step SC3), the stored image is replaced with the third and subsequent images as when the shutter button was initially pressed. If not (NO in step SC4), the frame image captured this time is transferred to the memory card 12 and recorded (step SC13). If the shutter button has been pressed (YES in step SC14), when the next imaging cycle has arrived (YES in step SC15), the process returns to step SC2 to perform the second imaging.
[0048]
Thereafter, the third imaging is performed by the same processing, and when the temporary storage of the third frame image in the DRAM 9 is completed (YES in step SC4), first, whether the high frame rate imaging mode is set at that time is determined. Is confirmed (step SC5). When the result of the determination is YES, such as immediately after the third imaging, the frame image of the previous frame stored in the DRAM 9 is compared with the current frame image (step SC6). If the frame rate shooting mode has not been set (NO in step SC5), the previous frame image stored in the DRAM 9 is compared with the current frame image (step SC7). The comparison processing in steps SC6 and SC7 is the same as the processing in step SA4 in the first embodiment, and finally obtains a change amount indicating the degree of change between the two images.
[0049]
Subsequently, it is determined whether or not the amount of change obtained in step SC6 or SC7 exceeds a predetermined threshold (step SC8), and the following processing is performed according to the determination result.
[0050]
That is, if the amount of change does not exceed the predetermined threshold, that is, if the amount of change is small (NO in step SC8), the shooting mode set at that time is not a high frame rate shooting mode. (NO in Step SC9), the current frame image captured in Step SC2 is transferred to the memory card 12 and recorded (Step SC13). Conversely, if the high frame rate shooting mode is set at that time (YES in step SC9), the shooting mode is switched to the low frame rate shooting mode (step SC10), and the current frame image is stored in the memory card 12. The data is transferred and recorded (step SC13).
[0051]
On the other hand, if the result of the determination in step SC8 is YES and the amount of change exceeds a predetermined threshold, that is, if the amount of change is large, the shooting mode set at that time is If the mode is not the low frame rate shooting mode (NO in step SC11), the current frame image is transferred to the memory card 12 and recorded (step SC13). Conversely, if the low frame rate shooting mode is set at that time (YES in step SC11), the shooting mode is switched to the high frame rate shooting mode (step SC12), and the current frame image is stored in the memory card 12 (step SC12). (Step SC13).
[0052]
After the captured frame image is recorded, while the shutter button is kept pressed (YES in step SC14), the next imaging cycle set according to the currently set imaging frame rate arrives. At this point (YES in step SC15), the process returns to step SC2, performs new imaging, temporarily stores the captured image, and repeats the above-described processing up to step SC13. Then, when the shutter button is released (NO in step SC14), the moving image photographing process ends at that point.
[0053]
As described above, in the present embodiment, the imaging frame rate is changed between the high frame rate and the low frame rate in accordance with the degree of change between the current image and the previous or last-last image (past image). Change the recording frame rate. At the same time, the image to be compared with the current image is switched between the previous image and the image two times before according to the changed imaging frame rate (recording frame rate), and as a result, the degree of change based on the same time reference is obtained. The recording frame rate is changed based on. As a result, the recording frame rate is changed based on the degree of change of the image within the same time interval at each time point, that is, the degree of change based on the same time reference. Therefore, also in the present embodiment, since an appropriate recording frame rate can always be set, a change between arbitrary consecutive frame images does not become large (small) as compared with other points in time, and natural A video that can be reproduced in a proper state can be shot with a smaller number of images.
[0054]
On the other hand, FIG. 7 illustrates two frame images fg1 to dg9 captured during the above-described moving image capturing, which are compared with each other when the low frame rate capturing mode and the high frame rate capturing mode are set. It is a figure showing a relation. In this embodiment, there is no problem when the shooting mode is switched from the high frame rate shooting mode to the low frame rate shooting mode, but when the shooting mode is switched from the low frame rate shooting mode to the high frame rate shooting mode, immediately after the switching. In this case, the interval of the imaging time between the current frame image fg4 and the frame image fg2 just before the comparison is different from the other cases. Therefore, in a case where strict processing is required, a method of switching a threshold value used as a criterion of a change amount, as described in the second embodiment, only at a time immediately after the above-described switching. Therefore, it is necessary to take measures to make the interval of the imaging time between both frame images to be compared coincide with another time point.
[0055]
By the way, in the first to third embodiments described above, moving image data (a plurality of frame images) recorded in the storage memory (memory card 12) and having a non-constant recording frame rate is converted into a fixed reproduction frame. When the playback is performed at the rate (reading speed), the shooting timing and the playback timing are naturally shifted, and a portion appears as if slow playback or fast-forward playback is performed. In this regard, when it is desired to match the shooting timing with the playback timing, for example, the change information of the shooting (playback) frame rate is embedded in the moving image file, and at the time of playback, the playback time of a predetermined frame image is determined based on the change information. By changing the reproduction frame rate (reproduction time) in, it is possible to reproduce a natural moving image in which the shooting timing and the reproduction timing match.
[0056]
In the first to third embodiments, the frame image is transferred and recorded from the buffer memory to the storage memory every time one image is shot. Is stored in a predetermined area of the buffer memory as an image to be saved for each shooting without transferring and recording to the storage memory for each shooting, and at the time when the shooting of the moving image is completed, all the images stored in the buffer memory are used for the moving image. A file may be created, and the moving image file may be transferred and recorded in the storage memory.
[0057]
In the above description, the case where the present invention is applied to an electronic still camera with a moving image shooting function has been described. However, the present invention relates to a movie camera with a still image shooting function, a mobile phone with a camera, a PDA with a camera, and a PDA with a camera. It can also be used for devices such as personal computers. In short, the present invention can be applied to any device having a moving image shooting function.
[0058]
【The invention's effect】
As described above, in the moving image photographing apparatus and the moving image photographing method of the present invention, when the recording frame rate is changed according to the change of the subject, the recording frame rate can always be changed and set at an appropriate timing. did. Therefore, a moving image that can be reproduced in a natural state can be shot with a smaller number of images.
[0059]
In the moving image photographing apparatus according to the third aspect, it is possible to prevent the recorded images from being thinned out more than necessary in a case where the degree of change between the frame images sequentially detected during photographing is continuously small. I made it. Therefore, even when large changes occur continuously in the subject, it is possible to capture a moving image that can be reproduced in a more natural state.
[0060]
Further, by using the program of the present invention, the present invention can be implemented in an existing moving image photographing apparatus.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electronic still camera showing each embodiment of the present invention.
FIG. 2 is a flowchart illustrating an operation at the time of capturing a moving image according to the first embodiment.
FIG. 3 is a flowchart illustrating an operation at the time of capturing a moving image according to a second embodiment.
FIG. 4 is a flowchart following FIG. 3;
FIG. 5 is a flowchart illustrating an operation at the time of capturing a moving image according to the third embodiment.
FIG. 6 is a flowchart following FIG. 5;
FIG. 7 is a diagram showing a relationship between a frame image captured during moving image shooting and two frame images to be compared in the embodiment.
[Explanation of symbols]
1 electronic still camera
2 CCD
3 DSP / CPU
4 TG
5 Unit circuit
6 Display device
7 Key input section
8 Data bus
9 DRAM
10 Built-in flash memory
11 Interface
12 Memory card

Claims (7)

In a moving image photographing apparatus that continuously captures an image of a subject by an imaging unit and records a moving image with the captured image as a frame image in a recording unit,
The degree of change of an image within the same time interval in an image continuously imaged by the imaging means is detected, and the imaging time interval of each image recorded in the recording means as a frame image is controlled based on the detection result. A moving image photographing apparatus comprising a control unit. The control means includes:
Detecting means for comparing the previous image and the current image of the subject imaged in the imaging operation at the same time interval by the imaging means, and detecting the degree of change between the two images;
Determining means for determining whether or not the current image can be recorded on the recording means based on a detection result of the detecting means;
2. The moving image photographing apparatus according to claim 1, further comprising: a recording control unit that causes the recording unit to record only a current image determined to be recorded by the determination unit as a frame image. The recording control unit, when the previous image is not recorded in the recording unit, stores the current image as a frame image in the recording unit irrespective of the determination result of the determination unit. The moving image photographing device according to claim 2. The control means includes:
Detecting means for comparing the previous image captured by the image capturing means with the current image, and detecting the degree of change between the two images;
Judging means for judging whether or not the imaging interval of the image by the imaging means can be changed based on the detection result of the detection means;
An imaging interval changing unit that changes an imaging interval of an image in the imaging unit when it is determined that the imaging interval should be changed by the determination unit;
2. The image forming apparatus according to claim 1, further comprising: a criterion changing unit configured to change a criterion for determining whether the imaging interval can be changed by the determining unit to a criterion corresponding to the changed imaging interval by the imaging interval changing unit. Video shooting device. The control means includes:
Detecting means for comparing the current image captured by the image capturing means with a past image captured before the current image, and detecting a degree of change between the two images;
Judging means for judging whether or not the imaging interval of the image by the imaging means can be changed based on the detection result of the detection means;
An imaging interval changing unit that changes an imaging interval of an image in the imaging unit when it is determined that the imaging interval should be changed by the determination unit;
When detecting the degree of change between the two images in the detecting means, a past image to be compared with the present image is compared with the image by the imaging means at a predetermined time according to the changed imaging interval by the imaging interval changing means. 2. The moving image photographing apparatus according to claim 1, further comprising: a comparison image changing unit that changes the image to an image captured by the method. In a moving image capturing method of continuously capturing an image of a subject by an imaging unit and recording a moving image having the captured image as a frame image,
A step of detecting a degree of change of an image within the same time interval in an image continuously captured by the imaging unit;
Controlling the image capturing time interval of each image to be recorded in the recording means as a frame image based on the detection result. A computer having a moving image photographing apparatus that continuously captures an image of a subject by an imaging unit and records a moving image with the captured image as a frame image in a recording unit,
The degree of change of an image within the same time interval in an image continuously imaged by the imaging means is detected, and the imaging time interval of each image recorded in the recording means as a frame image is controlled based on the detection result. A program for functioning as control means.

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