JP4381952B2 - Recording / playback device - Google Patents

Description

  The present invention relates to a recording / reproducing apparatus capable of storing and reproducing image data from a plurality of imaging devices such as a monitoring system.

In recent years, image data (for example, digital data) output one after another from a plurality of imaging devices (cameras) such as a monitoring system is stored (almost) simultaneously without switching, and the stored image data is read out for each camera. There is a recording / reproducing apparatus capable of simultaneously displaying image data.
For example, when such a recording / reproducing device is applied to a security vehicle, a camera is mounted so that image data in a plurality of directions such as the front and rear of the vehicle can be obtained, and image data in a plurality of directions is obtained while traveling. It can be used as various evidence by memorizing it and reproducing it as necessary.

In the prior art described in Patent Document 1, a plurality of cameras are used, and a synchronization shift is generated while switching a video signal from each camera with a video switcher without wiring a synchronization signal cable between the cameras. There has been proposed a video signal switching device capable of displaying on a plurality of monitors and recording video signals from a plurality of cameras on one VTR. In this video signal switching device, the video signal is separated into an image signal and a synchronization signal, and the video signal is switched using the synchronization signal.
Further, in the conventional technique described in Patent Document 2, a video processing system capable of processing video signals from a plurality of cameras controlled synchronously without causing a phase shift due to a difference in camera cable length. Has been proposed. In this video processing system, a synchronization control signal to be output to another camera is generated so that the synchronization signal of the video signal from one camera matches the phase of the synchronization signal of the video signal from the other camera. .
Note that the video signals described in Patent Documents 1 and 2 are analog signals.
JP-A-8-9313 JP-A-9-37141

When image data from a plurality of cameras is stored and then played back, and when no synchronization control signal is output to the cameras, each camera has a predetermined time interval (for example, 1 / Image data is output at intervals of 30 seconds. In this case, it is unlikely that a plurality of cameras start outputting image data at the same time. For example, output of image data is started at various time differences of about several ms. In addition, it is unlikely that each camera will have the exact same time. For example, if one camera measures 1 hour, it takes 59 minutes 59 seconds, and another camera takes 60 minutes 01 seconds. To do.
Accordingly, the time difference between the image data from each camera constantly fluctuates not only at the start of storage but also during the storage.
In this case, when the image data stored for security is reproduced and the image data taken by a plurality of cameras at a certain point in time is displayed simultaneously and used as evidence, the time difference between the image data may be important. Conceivable.

In the conventional technique described in Patent Document 1, since recording is performed on a VTR, an image signal separated from a video signal is converted into digital data by an A / D converter and temporarily stored in a memory. It is converted into analog data by the A converter and stored in the VTR. However, since the time difference of the video signal between the cameras is not particularly described, it is estimated that the time difference of the image signal between the cameras cannot be known or very difficult during reproduction.
In the prior art described in Patent Document 2, since the synchronization control signal is generated so that the phases of the synchronization signals of the video signals from the plurality of cameras coincide with each other, the time difference between the image signals between the cameras is different from the generated synchronization. It can be estimated by the time difference of the control signal. However, it is necessary to connect a cable for inputting a synchronization control signal to each camera, and a circuit for generating the synchronization control signal is required (the camera also needs a camera that supports synchronization control), which complicates the system.

  The present invention was devised in view of such points, and sequentially stores image data output one after another from a plurality of imaging devices with a simpler configuration, and the time difference of the image data between the imaging devices. It is an object of the present invention to provide a recording / reproducing apparatus capable of confirming information related to reproduction at the time of reproduction.

As means for solving the above-mentioned problems, the first invention of the present invention is a recording / reproducing apparatus as described in claim 1.
The recording / reproducing apparatus according to claim 1 is a recording / reproducing apparatus including a plurality of imaging devices that output image data at predetermined time intervals with reference to each timer, a storage unit, and a control unit.
In the recording mode in which the image data input from each imaging device is sequentially stored in the storage unit, the control unit captures the input image data based on the imaging device identification information, the frame number, and the input time of the image data. When the time is given and stored in the storage means, the predetermined time measured by each of the imaging devices using its own timer has a slight deviation in each imaging device, and each imaging device The output timing deviation of the image data output from A is accumulated over time, from another imaging device b to the image data [n] a that is the n-th image data from the imaging device a. The image data [n] b that is the n-th image data of the image data [n] a is equal to or longer than the period Ta that is the output period of the image data from the imaging device a. Is delayed, the n + m-th image data [n + m] b after the n-th image data [n] b from the imaging device b is assigned a frame number n + m + 1 without being assigned a frame number n + m. Then, the deviation of the output timing of the image data between the imaging device a and the imaging device b is corrected.
In the playback mode in which the image data stored in the storage means is read out and displayed for output , the control means reads out the image data to which different imaging device identification information is assigned and the same frame number is simultaneously read. In addition to being capable of display output, at least one of the capture time given to the image data or the time difference based on the capture time can be displayed and output simultaneously with the image data being displayed and output.

A second aspect of the present invention is a recording / reproducing apparatus as set forth in the second aspect.
The recording / reproducing apparatus according to claim 2 is a recording / reproducing apparatus including a plurality of imaging devices that output image data at predetermined time intervals with reference to each timer, a storage unit, a display unit, and a control unit. is there.
In the recording mode in which the image data input from each imaging device is sequentially stored in the storage unit, the control unit captures the input image data based on the imaging device identification information, the frame number, and the input time of the image data. When the time is given and stored in the storage means, the predetermined time measured by each of the imaging devices using its own timer has a slight deviation in each imaging device, and each imaging device The output timing deviation of the image data output from A is accumulated over time, from another imaging device b to the image data [n] a that is the n-th image data from the imaging device a. The image data [n] b that is the n-th image data of the image data [n] a is equal to or longer than the period Ta that is the output period of the image data from the imaging device a Is delayed, the n + m-th image data [n + m] b after the n-th image data [n] b from the imaging device b is assigned a frame number n + m + 1 without being assigned a frame number n + m. Then, the deviation of the output timing of the image data between the imaging device a and the imaging device b is corrected.
Further, the control means reads out the image data to which different imaging device identification information is given and the same frame number is given in the reproduction mode in which the image data stored in the storage means is read and displayed on the display means. Can be displayed simultaneously on the display means, and at least one of the capture time given to the image data or the time difference based on the capture time can be displayed simultaneously with the image data displayed on the display means. .

If the recording / reproducing apparatus according to claim 1 is used, it is possible to simultaneously display and output image data having different imaging device identification information and the same frame number, and to each image data. It is possible to display and output at the same time as the image data displaying and outputting at least one of the current capture time or the time difference based on the capture time. For this reason, when a monitor or the like reproduces the stored image data, information regarding the time difference of the image data between the imaging devices can be clearly confirmed at the time of reproduction.
In addition, a synchronization control signal is not required for the imaging apparatus, and a simpler configuration can be achieved.

  Further, the recording / reproducing apparatus according to claim 2 is provided with display means for the recording / reproducing apparatus according to claim 1. For this reason, for example, the stored image data can be confirmed in the reproduction mode on the spot where the image data is recorded, which is convenient. In the recording mode, for example, it is possible to store the image data while confirming the stored image data, which is convenient.

The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration and operation of a recording / reproducing apparatus 1 of the present invention.
● [Configuration and operation of recording and playback device (Fig. 1)]
The recording / reproducing apparatus 1 includes a plurality of imaging devices 10a and 10b (for example, CCD cameras, hereinafter referred to as cameras 10a and 10b), a control unit 30 (hereinafter referred to as CPU 30), and a storage unit 40 (for example, Hard Disk Drive) and display means 50 (for example, an LCD monitor). In addition, although the example shown in FIG. 1 has shown the example comprised with two imaging devices, you may comprise with three or more imaging devices. In the following description, an example using two imaging devices (camera 10a and camera 10b) will be described.
A compression unit (for example, a compression IC) that compresses image data may be provided between each camera (10a and 10b) and the CPU 30.

The recording / reproducing apparatus 1 in the present embodiment can be operated in at least one of a recording mode and a reproduction mode (the operation in either one mode can be performed simultaneously in both modes). It is also possible).
In the recording mode, the cameras 10a and 20b output image data one after another at a predetermined time interval (for example, 1/30 second). In this embodiment, the unit of the image data output from the camera may be a frame unit or a field unit. However, in the following, “frame (frame)” is referred to as a unit of image data (frame = image data). ).
In the present embodiment, the camera 10a and the camera 10b are asynchronous with each other, that is, each is asynchronous with each other. The camera 10a has image data (Da [i], Da at predetermined time intervals with reference to the internal timer of the camera 10a). [I + 1], Da [i + 2]... Are output to the CPU 30, and the camera 10b receives image data (Db [i], Db [i + 1], Db [i + 2] at predetermined time intervals with reference to the internal timer of the camera 10b. ..) is output to the CPU 30.
Then, the CPU 30 sequentially stores the input image data in the storage unit 40.

In the playback mode, the CPU 30 reads the image data from the storage unit 40 and simultaneously displays the image data for each camera on the display unit 50. In the example shown in FIG. 1, in the display means 50, the image data from the camera 10a is displayed on the 50a part of the display means 50, and the image data from the camera 10b is displayed on the 50b part of the display means 50.
In the present embodiment, when the CPU 30 stores each image data in the storage means 40 in the recording mode, the capture time for each image data is also stored, so that between the image data displayed on the display means in the playback mode. The display is performed so that the time difference between the image data on the camera 10a side and the image data on the camera 10b side can be discriminated. The details will be described below.

● [Image data input state in ideal state (Fig. 2)]
Next, the input state of image data in the ideal state will be described with reference to FIG. The “ideal state” means that the internal timers of the camera 10a and the camera 10b are ticking at exactly the same interval (the output cycle Ta of the image data from the camera 10a = the output cycle of the image data from the camera 10b). Tb), and the time difference between the image data output from the two cameras (TD in FIG. 2) is always the same time difference. Hereinafter, “image data” is referred to as “frame”.

Further, in the present embodiment described below, the capture time based on the input time of each frame is described as being set when the input of the frame is completed, but the capture time may be set at the start of frame input. The CPU 30 determines the capture time.
In the present embodiment, the camera 10a, the camera 10b, and the CPU 30 use the time by the CPU 30 as a reference in a state where each of the cameras 10 has its own time based on each timer. In the present embodiment, it is not necessary to store the absolute time, but it is only necessary to store information regarding the relative time difference between frames (between frames having the same frame number) for each camera. There is no particular problem with respect to the time.
In the example shown in FIG. 2, the camera 10a and the camera 10b output a frame every 1/30 seconds in the ideal state. The numbers (1, 2, 3,...) Described above each frame are frame numbers assigned by the CPU 30 to each frame.
Further, the period of the frame output from the camera is referred to as a frame period Ta (frame period Tb).

In the ideal state (frame period Ta = frame period Tb), the relative time difference (TD in FIG. 2) between the frames output from the two cameras is constant. For this reason, when the frame having the same frame number for each camera is simultaneously displayed on the display means 50 during the reproduction of the stored data, the time difference is TD (constant).
However, even when a plurality of cameras are used asynchronously and the frame period is set to the same output period, the internal timer of each camera often has a subtle “deviation” in practice. Also, the timing for starting the output of the frame is often not the same, and there is often a “deviation” even when the output of the frame is started. Therefore, there is a high possibility that the time difference varies for each frame number.
Therefore, by storing and reproducing by the method described below, it is possible to clearly recognize the time difference for each frame number at the time of reproduction.

[Storage method when frame period Ta <frame period Tb (FIG. 3)]
Next, the case where the frame period Ta of the camera 10a is shorter than the frame period Tb of the camera 10b will be described with reference to FIG.
For example, the reference camera is set to the camera 10a. In this case, since the frame period Ta is shorter than the frame period Tb, the frame output timing from the camera 10b is gradually delayed with respect to the frame output timing from the camera 10a, and the time difference between frames for each camera is different. Gradually grows.

Therefore, a frame number is assigned based on a frame output from the camera set as a reference (in this case, the camera 10a), and imaging apparatus identification information (information indicating which camera the frame is from, hereinafter “camera number”). ”), A frame number, and a capture time based on the input time of the frame (in this example, the time when the input is completed) are stored in the storage unit 40.
FIG. 5A shows an example of frames stored in the storage unit 40. The frames stored in the storage means 40 are stored by adding header information to the frames (image data) input from the camera. The header information includes the above camera number, frame number, and capture time.

In the example shown in FIG. 3, since the frame period Tb is longer than the frame period Ta, if the frame numbers are assigned to the cameras in the order of 1, 2, 3,. Is a time difference delayed by one cycle or more with respect to the frame from the camera 10a. In the example of FIG. 3, frame number 11 (before correction) from the camera 10b corresponds to the time point.
In this case, the frame number 11 (before correction) of the camera 10b is corrected to the frame number 12 (after correction) of the camera 10b.
Therefore, in this case, there is no frame corresponding to the frame number 11 from the camera 10b, but there is no particular problem because the frame itself does not disappear.

In the state shown in FIG. 3, when the above header information is added and each frame is stored, when the contents of the header information are listed, a frame list 40a shown in FIG. 5B is obtained. The frame list 40a is not particularly required to be stored in the storage means 40 (of course, may be stored), and is shown for explanation.
In the capture time in the frame list 40a, for example, the top capture time indicates a time of 13h (hours) 45m (minutes) 12s (seconds) 034ms (msec).
In the example of the frame list 40a shown in FIG. 5B, the time difference is also shown for each frame. For example, the time difference is “camera 10b side capture time” − “camera 10a side capture time” at the same frame number. Can be obtained.

[Storage method when frame period Ta> frame period Tb (FIG. 4)]
Next, the case where the frame period Ta of the camera 10a is longer than the frame period Tb of the camera 10b will be described with reference to FIG.
For example, the reference camera is set to the camera 10a. In this case, since the frame period Ta is longer than the frame period Tb, the frame output timing from the camera 10b gradually advances with respect to the frame output timing from the camera 10a, and the time difference between frames for each camera is increased. Gradually grows.

Therefore, first, frame numbers are allocated based on frames output from the camera set as a reference (in this case, the camera 10a at the start of frame number allocation).
Similarly to the description of FIG. 3, the storage unit 40 stores a frame to which a camera number, a frame number, and a capture time based on the input time of the frame (in this example, the time when input is completed). The form of the frame memorize | stored in the memory | storage means 40 is a form shown to FIG. 5 (A).

In the example shown in FIG. 4, since the frame period Tb is shorter than the frame period Ta, if the frame numbers are assigned as 1, 2, 3,. There may occur a case where there are two frames from the camera 10b (the timing of capturing two frames (timing when input is completed)) in one frame period of the camera 10a. In the example of FIG. 4, frame numbers 5 and 6 from the camera 10b correspond to the time point.
Here, the camera to be set as the reference is corrected from the camera 10a to the camera 10b at the capturing time timing (input completion timing) of the frame number 6 of the camera 10b ("reference (two-dot chain line in FIG. 4)". ) "). Accordingly, the camera 10a is set as a reference for frame numbers 1 to 5, and each frame number 5 corresponds to one frame.
After frame number 6, the reference is corrected so that the camera 10b becomes the reference.

Further, in the portion of frame number 14 (before correction) of the camera 10a, the same phenomenon (time difference is 1 frame period or more) as that of the frame number 11 of the camera 10b in the example of FIG. 3 occurs.
In this case, the frame number 14 (before correction) of the camera 10a is corrected to the frame number 15 (after correction) of the camera 10a.
Therefore, in this case, there is no frame corresponding to the frame number 14 from the camera 10a, but there is no particular problem because the frame itself does not disappear.

In the state shown in FIG. 4, when the header information is added and each frame is stored, when the contents of the header information are listed, a frame list 40b shown in FIG. 5C is obtained. The frame list 40b does not need to be stored in the storage means 40 in particular (may be stored as a matter of course), and is shown for explanation.
It should be noted that the time difference in the frame list 40b shown in FIG. 5C is that the time difference = “camera 10b side capture time” − “camera 10a side capture time” even if the reference camera is changed. Absent. Therefore, after frame number 6, the time difference is-(minus).
The other points are the same as those described in the frame list 40a, and thus the description thereof is omitted.

● [Example of display on display means (Fig. 6)]
Next, FIG. 6 shows an example of display on the display means 50 in the reproduction mode.
In the reproduction mode, the CPU 30 can read the image data stored in the storage means 40 and display the image data assigned with different camera numbers and assigned the same frame number on the display means 50 at the same time. In addition, at least one of the capture time given to the image data or the time difference based on the capture time can be displayed simultaneously with the image data displayed on the display unit 50.

For example, in the state shown in the example of FIG. 3, a camera number, a frame number, and a capture time are assigned to each frame and stored in the storage unit 40, and the user operates the playback mode to obtain “(time) 13h45m12s190ms”. specify.
Then, the recording / reproducing apparatus 1 reads out the frame corresponding to “frame number 6” which is after the designated time and is closest to the designated time from the storage unit 40 and displays it simultaneously (side by side) on the display unit 50. It is possible. In this case, a frame of the camera 10a to which the frame number 6 is assigned (frame of capture time: 13h45m12s199ms) and a frame of the camera 10b to which the frame number 6 is assigned (frame of capture time: 13h45m12s219ms) are displayed. .

The CPU 30 can display the above two frames on the display means 50 and simultaneously display at least one of the capture time of each frame or the time difference between frames. The example shown in FIG. 6 shows an example in which both the capture time of each frame and the time difference between frames are displayed simultaneously.
For example, in the example shown in FIG. 6, a decisive moment is captured in the frame of the camera 10a that captures the front side of the security vehicle and the frame of the camera 10b that captures the rear side of the vehicle, and the time difference between the two frames. Is clearly +20 ms. As a result, it is possible to compensate for the shortcomings in the evidence ability as a frame in which the decisive moment is copied.
As described above, when the recording / reproducing apparatus 1 of the present invention is used, image data sequentially output from a plurality of imaging devices is sequentially stored with a simpler configuration, and the time difference of the image data between the imaging devices It is also possible to confirm information regarding the playback.
In the above description, an example in which the “capture time” is designated and displayed on the display unit 50 has been described. However, it is also possible to designate the “frame number” and cause the display unit 50 to display the frame.

In the recording / reproducing apparatus 1 described above, the example in which the display unit 50 is provided has been described, but the display unit 50 may not be provided. Even if the display means 50 is not provided, the recording / reproducing apparatus 1 can store the image data as described above in the recording mode.
Even if the display unit 50 is not provided, the recording / reproducing apparatus 1 reads out the image data stored in the storage unit 40 in the reproduction mode, is assigned a different camera number, and is assigned the same frame number. Image data can be displayed and output at the same time, and at least one of the capture time given to the image data or the time difference based on the capture time can be displayed and output simultaneously with the image data being displayed and output . At this time, if an arbitrary display means 50 is connected, the display content being displayed and output can be confirmed, and the degree of freedom for selecting the display means 50 is improved.

The recording / reproducing apparatus 1 of the present invention is not limited to the configuration, operation, processing, and the like described in the present embodiment, and various changes, additions, and deletions can be made without changing the gist of the present invention.
For example, when the recording / reproducing apparatus 1 is mounted on a plurality of security vehicles, the identification data (identification information unique to the recording / reproducing apparatus 1 in this case, which corresponds to an ID unique to the vehicle) May be stored, and when the recorded image is reproduced, the identification data may be displayed on the display means 50 so that the recorded image on the recording / reproducing apparatus 1 can be known. . As a result, when the storage means 40 storing the image data is removed by the recording / reproducing apparatus 1 and reproduced by a different recording / reproducing apparatus 1 (for example, the storage means 40 stored in the recording / reproducing apparatus 1 installed in the security vehicle is removed. When the data is reproduced by connecting to the recording / reproducing apparatus 1 of the headquarters), it can be clearly seen which recording / reproducing apparatus 1 stores the image data.
In this embodiment, the example using two cameras (camera 10a and camera 10b asynchronous to each other) has been described, but the present invention can also be applied to the case of using three or more cameras (asynchronous to each other). .
The frame lists 40a and 40b are not limited to the examples shown in FIGS.
Further, the numerical values and the like used in the description of the present embodiment are examples, and are not limited to these numerical values and the like.

  The recording / reproducing apparatus 1 of the present invention can be applied to various recording apparatuses that store image data from a plurality of imaging apparatuses such as a monitoring apparatus.

It is a figure explaining the example of a structure and operation | movement of the recording / reproducing apparatus 1 of this invention. It is a figure explaining the input state of the image data in an ideal state. It is a figure explaining the memory | storage method in case of frame period Ta <frame period Tb in this Embodiment. It is a figure explaining the memory | storage method in case of frame period Ta> frame period Tb in this Embodiment. It is a figure explaining the example of the frame lists 40a and 40b. It is a figure explaining the example which displays simultaneously the information regarding the time difference between frames with the flame | frame for every camera in reproduction | regeneration mode.

1 Recording / reproducing apparatus 10a, 10b Camera (imaging apparatus)
30 CPU (control means)
40 storage means 50 display means

Claims (2)

A recording / reproducing apparatus comprising a plurality of imaging devices that output image data at predetermined time intervals with each timer as a reference, storage means, and control means,
The control means
In the recording mode in which the image data input from each imaging device is sequentially stored in the storage unit , the input image data is given imaging device identification information, a frame number, and a capture time based on the input time of the image data. And when storing it in the storage means ,
The predetermined time that each of the imaging devices measures using its own timer has a slight deviation in each imaging device, and the deviation in the output timing of the image data output from each imaging device is time. Image data [n] as n-th image data from another imaging device b with respect to image data [n] a as n-th image data from a certain imaging device a. When b is delayed from the image data [n] a by a period Ta or more, which is an output period of the image data from the imaging device a,
The n + m-th image data [n + m] b after the n-th image data [n] b from the imaging device b is assigned with a frame number n + m + 1 without being assigned a frame number n + m, and is stored. a shift in output timing of image data between a and the imaging device b is corrected,
In the playback mode in which the image data stored in the storage means is read out and displayed for output, the image data to which different imaging device identification information is assigned and the same frame number is read out and can be simultaneously displayed and output. In addition, at least one of the capture time given to the image data or the time difference based on the capture time can be displayed and output simultaneously with the image data being displayed and output.
And a recording / reproducing apparatus. A recording / reproducing apparatus comprising a plurality of imaging devices that output image data at predetermined time intervals with reference to each timer, storage means, display means, and control means,
The control means
In the recording mode in which the image data input from each imaging device is sequentially stored in the storage unit , the input image data is given imaging device identification information, a frame number, and a capture time based on the input time of the image data. And when storing it in the storage means ,
The predetermined time that each of the imaging devices measures using its own timer has a slight deviation in each imaging device, and the deviation in the output timing of the image data output from each imaging device is time. Image data [n] as n-th image data from another imaging device b with respect to image data [n] a as n-th image data from a certain imaging device a. When b is delayed from the image data [n] a by a period Ta or more, which is an output period of the image data from the imaging device a,
The n + m-th image data [n + m] b after the n-th image data [n] b from the imaging device b is assigned with a frame number n + m + 1 without being assigned a frame number n + m, and is stored. a shift in output timing of image data between a and the imaging device b is corrected,
In the reproduction mode in which the image data stored in the storage means is read out and displayed on the display means, the image data to which different imaging device identification information is assigned and the same frame number is read out and displayed on the display means simultaneously. And at least one of the capture time given to the image data or the time difference based on the capture time can be displayed simultaneously with the image data displayed on the display means.
And a recording / reproducing apparatus.

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