JP2013046125A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate an automatic stop mode of stopping recording automatically upon elapsing a prescribed time after start of shooting, and such an inconvenience as that a reproduction time is not fixed in an environment where the frame rate is fixed during reproduction.SOLUTION: A control unit (107) shortens a recording time of automatic stop mode as the frame rate increases when the frame rate of an imaging unit (101) is less than a predetermined value, otherwise fixes the recording time regardless of the frame rate. When reproducing a moving image recorded in the automatic stop mode with a frame rate higher than the predetermined value at the time of recording, the control unit (107) controls a signal processing unit (104) to thin the frames so that the reproduction time of a moving image in the automatic stop mode, when the frame rate is less than the predetermined value at the time of recording, is attained.

Description

  The present invention relates to an imaging apparatus.

  2. Description of the Related Art Conventionally, a video camera that captures a moving image and records it on a memory card or a disk medium is known. In a video camera, usually, shooting (recording) of a moving image is started according to an instruction to start shooting by a photographer, and recording is stopped according to an instruction to stop shooting.

  In addition to such a normal shooting function, there is also known a camera having a function of automatically stopping shooting when a predetermined time elapses from a shooting start instruction (see Patent Document 1). In recent years, video cameras capable of changing the frame rate of moving images to be recorded have also appeared. For example, a slow motion effect can be easily obtained by reproducing (displaying) a moving image shot (recorded) at a high frame rate at a low frame rate.

JP 2005-020484 A

  In order to obtain a slow motion effect, when a moving image recorded at a high frame rate is reproduced at a low frame rate, the reproduction time is longer than the recording time. In other words, when rate conversion playback is applied to a recorded image in the automatic stop mode in which recording is automatically stopped after a lapse of a certain time from the start of shooting, the playback time depends on the frame rate at the time of shooting and is not constant.

  When rate conversion playback is scheduled, it is conceivable to automatically adjust the frame rate to be calculated backward from a predetermined playback time. However, the higher the frame rate at the time of shooting, the shorter the shooting time and the lower the usability.

  An object of this invention is to show the imaging device which eliminates such an inconvenience.

  An imaging apparatus according to the present invention includes an imaging unit that outputs a moving image signal, a setting unit that sets a frame rate of the moving image signal output by the imaging unit, and a moving image signal obtained by the imaging unit is recorded on a recording medium. Recording means for starting the recording of the moving image signal in response to an instruction to start recording, and stopping the recording of the moving image signal according to the elapse of a set time after the recording of the moving image signal is started. Control means for controlling, when the frame rate set by the setting means is smaller than a predetermined value, the set time according to the frame rate so that the reproduction time of the moving image signal becomes a predetermined time And control means for determining the same value as the set time when the frame rate is equal to or higher than the predetermined value.

  According to the present invention, it is possible to provide an easy-to-use apparatus even when shooting is performed by changing the frame rate.

It is a schematic block diagram of one Example of this invention. It is a flowchart which shows the imaging | photography process of a present Example. It is a flowchart which shows the recording time setting process of a present Example. It is a table | surface which shows a response | compatibility with the frame rate and recording time of a present Example. It is a flowchart which shows the frame rate setting process of a present Example. It is a flowchart which shows the switching process to the 2nd imaging | photography mode of a present Example. It is a flowchart which shows the reproduction | regeneration processing of a present Example. It is a schematic diagram explaining frame thinning out of a moving image to be reproduced.

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

  FIG. 1 is a schematic block diagram of a video camera which is an embodiment of an imaging apparatus according to the present invention. The video camera 100 records a moving image signal according to a predetermined recording format. The moving image signal and other information recorded on the recording medium are managed as files according to a FAT (File Allocation Table) file system. The video camera 100 can change the frame rate (number of frames per unit time) of a moving image to be taken to any one of a plurality of predetermined frame rates.

  The configuration and basic operation of the video camera 100 will be described. The imaging unit 101 captures a subject, generates moving image data indicating the subject, and outputs it. The imaging unit 101 includes an imaging optical system, an imaging device, and a processing circuit that generates moving image data in a predetermined format from an output image signal of the imaging device. The photographing optical system includes a zoom lens, a focus lens, and a diaphragm. The audio input unit 102 includes a microphone, an amplifier, an AD converter, and the like, acquires ambient audio including a subject, and outputs audio data.

  The memory 103 stores moving image data output from the imaging unit 101, audio data from the audio input unit 102, display image signals, compressed moving image data, and other information.

  At the time of recording, the signal processing unit 104 subjects the captured moving image data to an encoding process according to a known encoding method such as MPEG, compresses the amount of information, and stores the compressed moving image data in the memory 103. The signal processing unit 104 reproduces the moving image data read from the recording medium during reproduction. That is, the compressed data is decompressed.

  The display control unit 105 displays moving images and various types of information on the display unit 106 in accordance with instructions from the control unit 107. The display unit 106 includes a known display device such as a liquid crystal panel.

  The control unit 107 includes a microcomputer and necessary memory. The control unit 107 controls the operation of each unit of the video camera 100 according to an instruction from the operation unit 108 according to a program stored in a non-illustrated nonvolatile memory. The operation unit 108 includes various switches such as a power switch operable by the user, a trigger switch for instructing start / stop of moving image shooting, a playback switch, and a menu switch. The control unit 107 receives a user instruction from the operation unit 108. Further, the control unit 107 displays a menu screen on the display unit 106 according to the user's operation of the menu switch. The user can change the operation mode and settings of the video camera 100 using this menu screen.

  The recording / playback unit 109 records moving image data, audio data, and various types of information on the recording medium 110 and plays back from the recording medium 110 in accordance with instructions from the control unit 107. The recording medium 110 is a randomly accessible recording medium such as a memory card or a hard disk (HDD). In this embodiment, the recording medium 110 is composed of a replaceable memory card with a built-in flash memory. Further, the recording medium 110 can be easily mounted on and discharged from the video camera 100 by a mounting / discharging mechanism (not shown).

  The output unit 111 outputs moving image data at the time of shooting or moving image data at the time of reproduction to an external device of the video camera 100. The internal bus 112 is used to transfer various data and commands between the units of the video camera 100.

  A recording process at the time of photographing according to the present embodiment will be described. The video camera 100 has a first shooting mode or a manual stop shooting mode in which recording of a moving image is started in response to a recording start instruction from a user, and recording of a moving image is stopped when a recording stop instruction is issued. The video camera 100 also starts the recording of a moving image in response to an instruction to start recording, and the second shooting mode in which the recording of the moving image is automatically stopped when a predetermined period, that is, a set time elapses after the recording starts. Has automatic stop shooting mode. The user can set any of these two shooting modes by operating the operation unit 108, and the video camera 100 operates in the set shooting mode.

  FIG. 2 is a flowchart showing processing in the photographing mode. When the user turns on the power of the video camera 100 or switches to the shooting mode by the operation unit 108, the imaging unit 101 outputs a moving image signal, and the display unit 106 displays an image of the photographed subject. In this state, when an instruction to start shooting is given by the operation unit 108, the flow shown in FIG. 2 starts. 2 is executed by the control unit 107 controlling each unit.

  The control unit 107 determines which of the first and second shooting modes is set (S201). If the first shooting mode is set, the control unit 107 starts recording moving images and sounds (S202). More specifically, the control unit 107 instructs the signal processing unit 104 to start video and audio encoding processing. In addition, the control unit 107 instructs the recording / reproducing unit 109 to multiplex the encoded moving image signal and audio signal according to the recording format of the recording medium 110 and record them on the recording medium 110.

  After starting recording in this way, the control unit 107 detects whether or not there is an instruction to stop recording by the user (S203). When there is an instruction to stop recording, the control unit 107 stops the encoding process of the moving image signal and the audio signal by the signal processing unit 104, and stops the recording of the moving image and the audio on the recording medium 110 (S204). In this embodiment, a series of scenes of moving images and audio from the start of recording to the stop of recording are recorded on the recording medium 110 as files. Then, the control unit 107 generates management information including shooting mode information indicating a shooting mode of the recorded moving image file, a frame rate, and a recording time (length) of the recorded moving image file, and outputs the management information to the recording / reproducing unit 109. . Here, the shooting mode information indicates the first shooting mode. Then, the recording / playback unit 109 records this management information on the recording medium 110 in association with the moving image file (S205).

  If the second shooting mode is set in S201, the control unit 107 determines and sets the shooting time (set time) based on the current frame rate as described later (S206). Then, similarly to S202, the control unit 107 controls each unit and starts recording moving images and audio (S207). Along with the start of recording, the control unit 107 starts measuring the elapsed time from the start of recording using a built-in counter.

  When the set time elapses after the recording is started (S208), the control unit 107 controls each unit to automatically stop the recording of the moving image and the sound (S204). Then, the control unit 107 controls the recording / reproducing unit 109 to record management information on the recording medium 110 (S205). However, the shooting mode information in the management information indicates the second shooting mode.

  The recording time setting process in step S206 will be described. In this embodiment, the recording time (set time) in the second shooting mode is set according to the frame rate of the moving image shot by the imaging unit 101. That is, in this embodiment, when a moving image is reproduced and displayed at a predetermined frame rate (here, 60 frames per second (fps)), the second time is set so that the reproduction time becomes a predetermined time (here, 12 seconds). Determine and set the recording time for the shooting mode.

  FIG. 3 is a flowchart showing the recording time setting process. The control unit 107 reads information on the currently set frame rate from the memory 103, and detects the current frame rate Fn (fps) (S301). Then, the control unit 107 detects the recording time T corresponding to the frame rate Fn based on the table stored in the memory 103 (S302), and sets the detected value as the recording time (set time) (S303).

  FIG. 4 is a table showing a correspondence example between the frame rate Fn and the recording time T. As is clear from FIG. 4, in the range of the frame rate from 12 fps to 120 fps, the recording time is determined according to the frame rate so that the reproduction time becomes 12 seconds when the captured moving image is reproduced at 60 fps. . For frame rates higher than 240 fps, the recording time is 3 seconds. This prevents an extremely short photographing time even when the frame rate is higher than 240 fps.

In this embodiment, the frame rate during reproduction is fixed at 60 fps, but this may be arbitrarily set by the user. The frame rate at the time of reproduction set by the user is Ft, and the shooting time is appropriately changed according to the frame rate Fn so that the reproduction time becomes T seconds when the moving image is reproduced at the frame rate Ft. Also good. In this case, the recording time is
Recording time = T × Ft / Fn
It can be calculated by However, when the calculated recording time is shorter than a threshold (for example, 3 seconds), the recording time is set as the threshold.

  Next, the frame rate setting process will be described. The user can set the frame rate of a moving image to be shot and recorded by the imaging unit 101 in the recording standby state in both the first shooting mode and the second shooting mode. In this embodiment, in the normal recording mode, any one of 12 fps, 15 fps, 24 fps, 30 fps, 60 fps, 120 fps, 240 fps, 480 fps and 960 fps can be set.

  FIG. 5 is a flowchart showing a frame rate setting process. In FIG. 5, when the user operates the operation unit 108 and a frame rate is designated, the control unit 107 sets the designated frame rate Fn as a new frame rate (S501). Then, the control unit 107 stores information on the currently set frame rate Fn in the memory 103.

  The control unit 107 determines whether or not the second shooting mode is currently set (S502). When the second shooting mode is set, the control unit 107 determines whether or not the newly set frame rate Fn is equal to or greater than a predetermined value (S503). In the numerical example described above, it is determined whether Fn is 240 fps or more. When Fn is equal to or larger than the predetermined value, the control unit 107 displays warning information indicating that the recording time in the second shooting mode is fixed to T seconds (here, 3 seconds) on the display unit 106 (S504). ).

  When the second shooting mode is not set or when the frame rate Fn is smaller than a predetermined value, the control unit 107 ends the process as it is.

  FIG. 6 shows a flowchart of the switching process to the second photographing mode. With reference to FIG. 6, the process at the time of switching to the second photographing mode will be described.

  When the control unit 107 receives an instruction to switch to the second shooting mode from the user, the control unit 107 reads the information of the frame rate Fn from the memory 103 and detects the currently set frame rate Fn (S601). The control unit 107 determines whether or not Fn is equal to or greater than a predetermined value (240 fps in the above numerical example) (S602). If Fn is equal to or greater than a predetermined value, the control unit 107 displays warning information indicating that the recording time in the second shooting mode is fixed to T seconds (here, 3 seconds) on the display unit 106. (S603). If Fn is not equal to or greater than the predetermined value, the control unit 107 ends the process as it is.

  FIG. 7 shows a flowchart of the reproduction process. The reproduction process will be described with reference to FIG.

  When the playback unit is instructed by the operation unit 108, the control unit 107 causes the recording / playback unit 109 to play back the top portion of the moving image data included in the moving image data file (moving image file) recorded on the recording medium 110. To control. The signal processing unit 104 decodes the head portion of the reproduced moving image signal and sends it to the display control unit 105. The display control unit 105 reduces the size of the decoded top screen, generates a representative image, and displays it on the display unit 106. At this time, information for identifying whether the image was taken in the first shooting mode or the second shooting mode may be displayed on the display unit 106. The user operates the operation unit 108 to select a desired representative image to be reproduced from the representative images of each moving image file displayed on the display unit 106 and to instruct reproduction.

  In accordance with the reproduction instruction, the control unit 107 controls the recording / reproducing unit 109 to reproduce the moving image file corresponding to the selected representative image. The recording / playback unit 109 reads the designated moving image file from the recording medium 110 and stores it in the memory 103. The signal processing unit 104 reads out the moving image data from the memory 103, decodes it, and stores it in the memory 103 again. The display control unit 105 reads the decoded moving image data from the memory 103 and displays the playback moving image on the display unit 106. Further, the signal processing unit 104 reads out the audio data from the memory 103, decodes it, and stores it again in the memory 103. The decoded audio data is output from a speaker (not shown).

  When there is an instruction to stop reproduction, the control unit 107 stops reproduction of the moving image file and causes the display unit 106 to display the representative image again.

  In this embodiment, the moving image is played back at 60 fps. Therefore, the playback time varies depending on the frame rate at the time of shooting. For example, when a moving image shot at 120 fps is reproduced, it is reproduced and displayed as a slow-motion moving image at 1/2 times speed. When a moving image shot at 30 fps is reproduced, it is reproduced and displayed as a double-speed fast motion moving image. In this embodiment, when the frame rate of a moving image to be reproduced is other than 60 fps, decoding of audio data is stopped and output of audio is stopped.

  When playing back a moving image recorded in the second shooting mode, the playback process differs depending on the frame rate at the time of recording. In this embodiment, in the second shooting mode, when the frame rate Fn is 240 fps or more, the recording time is fixed to 3 seconds. Therefore, for a moving image with a frame rate Fn of 240 fps or more, the playback time becomes longer than 12 seconds.

  Therefore, for a moving image having a frame rate Fn of a predetermined value or more, a reproduction time is made to coincide with a predetermined value (here, 12 seconds) by thinning and displaying a part of the frame. That is, for a moving image with frame rates of 480 fps and 960 fps, a part of the frame is thinned out and displayed so that the reproduction time is 12 seconds. If the frame rate of the moving image is other than 480 fps or 960 fps, all frames are displayed.

  FIG. 7 is a flowchart showing processing at the time of reproduction of a moving image recorded in the second shooting mode. The control unit 107 detects the frame rate of the designated moving image based on the management information recorded on the recording medium 110, and determines whether or not the frame rate Fn is a predetermined value (S701). Here, it is determined whether or not the frame rate Fn of the moving image is 480 fps or more.

  When the frame rate Fn is equal to or greater than the predetermined value, the control unit 107 determines whether or not thinning reproduction is set by the user (S702). When the thinning reproduction is set, the control unit 107 controls the recording / reproducing unit 109 and the signal processing unit 104 to reproduce the designated moving image file by thinning out the frames so that the reproduction time becomes 12 seconds. (S703). That is, the recording / playback unit 109 reads the designated moving image file from the recording medium 110. Further, the signal processing unit 104 decodes the read moving image file, and the display control unit 105 displays a part of the decoded moving image data by thinning out the frames. For example, when the frame rate is 480 fps, the display control unit 105 displays one frame by thinning out one frame. When the frame rate is 960 fps, the display control unit 105 selects and displays one frame every four frames.

  When the reproduction of the designated moving image ends (S704), the control unit 107 stops the reproduction (S705).

  When the frame rate Fn is equal to or higher than the predetermined value (S701) or when thinning reproduction is not designated (S702), the control unit 107 displays the decoded moving image without thinning out. Instruct. The display control unit 105 displays all frames of the decoded moving image data at 60 fps without thinning out (S706). When the reproduction of the designated moving image is completed (S704), the reproduction is stopped (S705).

  FIG. 8 is a schematic diagram illustrating a state of a frame output when a moving image recorded in the second shooting mode is reproduced. FIG. 8A shows an output frame sequence when thinning reproduction is not instructed. FIG. 8B shows an output frame sequence when thinning reproduction is instructed.

  As is clear from FIG. 8B, when thinning reproduction is instructed, a 480 fps moving image is thinned out for each frame and output. A moving image of 960 fps is output by thinning out one frame every four frames.

  When a moving image recorded in the second shooting mode is played back, a plurality of adjacent frames may be synthesized and output instead of being output by thinning out the frames. FIG. 8C shows an example in which the first frame and the second frame are combined for a 480 fps moving image to generate the first frame, and the first to fourth frames are combined for a 960 fps moving image. An example of generating a frame eye is shown.

  As described above, in this embodiment, the recording time in the second shooting mode is automatically set so that the reproduction time becomes a predetermined time when the moving image is reproduced and displayed at a frame rate different from that at the time of recording. Further, when the recording frame rate is equal to or higher than a predetermined value, the recording time is fixed, and during reproduction, thinning is performed to make the reproduction time constant. By these processes, even if the frame rate at the time of shooting can be changed, the recording time is not extremely shortened, and the reproduction time is reduced to a certain value, so that a good reproduction state can be ensured.

Claims (3)

Imaging means for outputting a video signal;
Setting means for setting a frame rate of the moving image signal output by the imaging means;
Recording means for recording the moving image signal obtained by the imaging means on a recording medium;
Control means for controlling the recording means to start recording the moving image signal in response to an instruction to start recording, and to stop recording the moving image signal in accordance with the elapse of a set time after the recording of the moving image signal starts. When the frame rate set by the setting means is smaller than a predetermined value, the set time is determined according to the frame rate so that the playback time of the video signal is determined, An image pickup apparatus comprising: control means for determining the same value as the set time when the frame rate is equal to or higher than the predetermined value.   The control means determines the set time so that when one moving image signal recorded on the recording medium is reproduced at a predetermined frame rate, the reproduction time becomes the predetermined time. The imaging apparatus according to claim 1. The control means warns that the setting time is set to the same value when the frame rate is changed to the predetermined value or more by the setting means. The imaging device described in 1.

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