Imaging device

Abstract

To provide an imaging device that can prevent a time in which a time of an imaging time code coincides with a time of a reference time code from being shortened, regardless of update timing of the time codes.SOLUTION: The present invention is characterized in that an imaging device having a function of adding an imaging time code to a moving image includes: generating means for generating a reference time code using as a reference; setting means for adjusting a time of the imaging time code with a time of the reference time code; first acquisition means for acquiring an updated time of the reference time code; and second acquisition means for acquiring an updated time of the imaging time code, wherein the setting means adjusts the time of the imaging time code to the time of the reference time code at timing corresponding to a time difference between the updated time of the reference time code and the updated time of the imaging time code.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an imaging device that uses a time code. [Background technology]

[0002] In order to identify the position of an image captured by an imaging device, a time code may be recorded along with the captured image. The time code consists of the time (hour, minute, second) and the frame number (for example, a number from 0 to 24 for 25 frames per second).

[0003] When shooting using multiple imaging devices, if the time codes of the images shot by each imaging device are synchronized, subsequent video editing using editing software etc. will be easier, so it is desirable that the time codes of those imaging devices are synchronized.

[0004] One method for setting time codes is to synchronize the times of multiple image capture devices, generate a time code from the synchronized time and the frame rate of the image capture devices, and set that time code as the time code of the image capture devices (Non-Patent Document 1). This allows the time codes of multiple image capture devices to be aligned.

[0005] Because an imaging device starts capturing images when it is started up in imaging mode, the update timing of the imaging time code depends on the start-up timing of the imaging device. The update timing of the reference time code generated from the time of an external device also depends on the generation timing of the reference time code. As a result, the update timing of the imaging time code and the reference time code may differ.

[0006] Patent Document 1 discloses a technique for correcting the generation timing of a video synchronization signal so that the update timing of an input time code coincides with a predetermined timing. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-67463 [Non-patent literature]

[0008] [Non-Patent Document 1] SMPTE ST2059-1 Summary of the Invention [Problem to be solved by the invention]

[0009] However, when generating a reference time code using software, the processing speed of software processing is generally slower than the processing speed of hardware processing, so it is often impossible to update the time code with the accuracy required by the imaging device. This makes it difficult to correct the imaging timing of the imaging device. Therefore, it is necessary to synchronize the time code while keeping the update timing of the imaging time code and the update timing of the reference time code different.

[0010] If the reference time code is set to the shooting time code while the update timing of each time code is different, the time (period) during which the shooting time code and the reference time code match may become shorter depending on the timing, which may cause problems when editing the video using editing software.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to prevent the time during which the time of the imaging time code and the time of the reference time code coincide from becoming shorter, regardless of the timing of updating the time code. [Means for solving the problem]

[0012] The present invention is an imaging device having the function of adding an imaging time code to a moving image, which comprises a generating means for generating a reference time code that serves as a reference, a setting means for adjusting the time of the imaging time code to the time of the reference time code, a first acquiring means for acquiring the update time of the reference time code, and a second acquiring means for acquiring the update time of the imaging time code, and is characterized in that the setting means adjusts the time of the imaging time code to the time of the reference time code at a timing corresponding to the time difference between the update time of the reference time code and the update time of the imaging time code. [Effects of the Invention]

[0013] According to the present invention, regardless of the timing of updating the time code, it is possible to prevent the time during which the time of the imaging time code and the time of the reference time code coincide from becoming shorter. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a block diagram showing a configuration of an imaging apparatus according to an embodiment of the present invention. [Figure 2] Network connection example of an imaging device that can implement the present invention [Figure 3] A flowchart for setting the reference time code to the imaging time code when the time difference is the time obtained by subtracting the update time of the reference time code from the update time of the imaging time code. [Figure 4] A flowchart for setting the reference time code to the imaging time code when the time difference is the time obtained by subtracting the update time of the imaging time code from the update time of the reference time code. [Figure 5] A flowchart for setting the reference time code to the shooting time code, adding a case where the time difference between the reference time code and the updated time code is half the time code update interval. [Figure 6] Relationship between time code and time DETAILED DESCRIPTION OF THE INVENTION

[0015] (Embodiment 1) The time code that an imaging device has and that is assigned to each captured frame is called the imaging time code. The imaging time code is a code that is assigned to each image (each frame) of a recorded video when the video is recorded in order to identify that image. In addition, the time code generated based on the time obtained from an external server is called the reference time code. The time code is usually composed of time information such as hours, minutes, and seconds, as well as a frame number.

[0016] Since the reference time code and the imaging time code have the same frame rate, in principle the update intervals for both the reference time code and the imaging time code are the same. However, depending on the form and configuration of the imaging device, it is also possible to make the update intervals for the reference time code and the imaging time code different, for example by making the update interval for one time code an integer multiple of the update interval for the other time code.

[0017] 1 shows an example of the configuration of an image capture device 101 according to this embodiment. The image capture device 101 has a CPU 102, a ROM 103, a DRAM 104, a file system 105, a bus 106, and a communication I / F (interface) unit 110. The CPU 102 stands for Central Processing Unit. The ROM 103 stands for Read Only Memory. The DRAM 104 stands for Dynamic Random Access Memory. The communication I / F unit 110 is a MAC that controls Ethernet (registered trademark). MAC stands for Media Access Control.

[0018] 1 is realized by the CPU 102 reading and executing a computer program stored in the DRAM 104. Alternatively, it may be realized by a dedicated hardware circuit.

[0019] Reference numeral 108 denotes a time synchronization unit that communicates with an external time server 201 via a network and synchronizes the time of a clock unit 109 with that of the external time server 201. Reference numeral 107 denotes a reference time code generation / acquisition unit. The reference time code generation unit 107 reads the time of the clock unit 109 and generates a reference time code based on the time.

[0020] Reference numeral 113 denotes an imaging time code counter which holds an imaging time code to be added to a frame of a captured moving image. The imaging time code counter 113 is configured to increment by one each time the imaging unit 117 captures one frame. Reference numeral 117 denotes the imaging unit which captures the image. Reference numeral 114 denotes an imaging time code adding unit which adds an imaging time code to the video data captured by the imaging unit. The imaging time code counter 113 is connected to the imaging unit 117 and is configured to receive an imaging timing signal for the frame from the imaging unit 117. Reference numeral 116 denotes a moving image recording unit which records the moving image data to which the imaging time code has been added.

[0021] Reference numeral 111 denotes a frame rate acquisition unit which acquires the current imaging frame rate of the imaging unit. Reference numeral 112 denotes an imaging time code setting and acquisition unit which can set an arbitrary value in an imaging time code counter 113 and can also acquire the value of the imaging time code counter 113. A program executed by the CPU 102 can acquire the current value of the imaging time code counter 113 from the imaging time code setting and acquisition unit 112. The imaging time code counter 113, whose imaging time code has been changed, is configured to increment by 1 when it receives an imaging start signal for the next frame from the imaging unit 117.

[0022] Reference numeral 118 denotes an imaging time code update notification unit, and 115 denotes an imaging time code update acquisition unit. When the imaging time code update notification unit 118 detects an update of the imaging time code, it notifies the imaging time code update acquisition unit 115. The computer program executed by the CPU 102 can know the time when the imaging time code was updated by reading the time on the clock unit 109 when the imaging time code update notification unit 118 notifies the time code update.

[0023] Reference numeral 119 denotes a reference time code update time acquisition unit, which can obtain, by calculation, the time at which the reference time code was updated at that time and the time at which the reference time code will be updated next at that time.

[0024] 2 shows an example of a network configuration in which two image capture devices 101 and a time server 201 are connected via a hub 202. 201 is a time server that distributes time. Image capture device 1 (101-1) and image capture device 2 (101-2) communicate with the time server 201 to synchronize the time in their respective clock units 109. 202 is a hub that is used to connect the time server 201, image capture device 1 (101-1), and image capture device 2 (101-2) via the network. Image capture device 1 (101-1) and image capture device 2 (101-2) synchronize with the time distributed by the time server 201, and set a reference time code generated from that time in the image capture time code counter 113. This allows the image capture time codes of image capture device 1 (101-1) and image capture device 2 (101-2) to be synchronized.

[0025] 3 is a flowchart of the time code setting in this embodiment. Each process in the flowchart of FIG. 3 is performed by each component in FIG.

[0026] Fig. 6 is a relationship diagram between time codes and time, showing on a time axis the relationship between the time from which the reference time code is generated, the reference time code generated from that time, the captured frame image, and the capture time code of the imaging device 101. In Fig. 6, 601 is the reference time code generated by the reference time code generation unit 107, 602 is the value (time) of the capture time code counter 113, 603 is the time from which the reference time code is generated, and 604 is the captured frame image. Fig. 6(A) shows the case where the time from when the reference time code is updated to when the capture time code is updated ("m" in Fig. 6(A)) is short, and Fig. 6(B) shows the case where "m" is long.

[0027] In this embodiment, the time at which the reference time code and the shooting time code match is set to the range indicated by "s" rather than the range indicated by "d" in Figures 6(A) and (B).

[0028] The detailed processing of this embodiment will be described below with reference to FIGS.

[0029] First, the computer program executed by the CPU 102 acquires the frame rate of the imaging device 101 from the frame rate acquisition unit 111 (step 302). Next, the time code update interval is acquired (step 303). The frame update interval calculated from the frame rate is the same as the update interval of the imaging time code. For example, if the frame rate is 25 fps (frame / sec), there are 25 frames per second, so the time code update interval is calculated to be 0.04 seconds.

[0030] Next, the CPU 104 waits for an imaging time code update notification from the imaging time code update notification unit 118 (step 304). When the imaging time code update notification unit 118 notifies the CPU 104 of an imaging time code update (step 305), the CPU 104 acquires the current time from the clock unit 109 (step 306). Then, the CPU 104 generates a reference time code from the time when the imaging time code update notification was received (step 307). Then, the CPU 104 acquires the update time of the generated reference time code (step 308).

[0031] For example, in (A) of FIG. 6, suppose an update to the shooting time code of (a) is notified and the time is 14:47:23.73 (14:47:23.73 seconds). If shooting at 25 fps, 0.73 seconds have passed since 14:47:23, and one frame is 0.04 seconds long, so 0.73 ÷ 0.04 = 18.25. Since there are no fractions in the frame count, we can see that this is the 18th frame from 14:47:23. Therefore, the time code is 14:47:23;18. Furthermore, since 18 × 0.04 = 0.72, the time code start time of 14:47:23;18 is 14:47:23.72 seconds. Similarly, if the time of image capture time code update in FIG. 6B(b) is 14:47:23.75, the reference time code value is 14:47:23;18, and the time code start time is 14:47:23.72.

[0032] Then, the time difference between the update time of the imaging time code and the update time of the reference time code (update time of the imaging time code - update time of the reference time code) is calculated (step 309) and compared with half the value of the time code update interval (step 310).

[0033] 6A, the time difference "m" between the update time of the imaging time code and the update time of the reference time code is 14:47:23.73-14:47:23.72=0.01 seconds, and half the time code update interval is 0.04÷2=0.02 seconds. Since the time difference (0.01 seconds) is smaller than half the time code update interval (0.02 seconds), the process proceeds from step 310 to step 311 (step 310-Y).

[0034] In step 311, the process waits until the imaging time code is updated by the imaging time code update notification unit (118). Then, the imaging time code update notification unit (118) notifies the update of the imaging time code (step 312). Next, the time is acquired from the clock unit 109 (step 315), and a reference time code is generated from the acquired time (step 316). The generated reference time code is then set as the imaging time code (step 317). Specifically, as shown in FIG. 6(A), the time of the imaging time code is adjusted to the time of the reference time code.

[0035] In Figure 6(A), the imaging time code update notification unit 118 notifies the update of the imaging time code at position "a'" in the figure. The time at "a'" is 14:47 minutes and 23.77 seconds, and the time code value at that time is 14:47:23:19. Then, after "a'", the reference time code is set at the timing shown as "t1" in Figure 6(A). Then, the period during which the time code times are the same will be the time shown as "s" in Figure 6(A), and the period during which the time code times match can be set to be longer.

[0036] As described above, when the time difference between the update time of the reference time code and the update time of the imaging time code is less than half the time code update interval ("m" in FIG. 6(A)), the reference time code is set between after the imaging time code is updated and before the reference time code is updated. By doing so, the period during which the reference time code time and the imaging time code time match can be set to be longer.

[0037] Return to step 310. The imaging time code update time at time point (b) in Figure 6(B) is 14:47:23.75. The start time of the reference time code 14:47:23;18 at that time is 14:47:23.72. The time difference "m" between the reference time code update time and the imaging time code update time is 14:47:23.75 - 14:47:23.72 = 0.03 seconds. Half the time code update interval is 0.02 seconds. Therefore, the time difference (0.03 seconds) is greater than half the time code update interval (0.02 seconds), so proceed from step 310 to step 313 (step 310-N).

[0038] In step 313, the next update time of the generated reference time code (the end time of the current reference time code) is obtained. The next update time of the reference time code is calculated as follows: When shooting at 25 fps, 0.75 seconds have passed since 14:47:23. Also, since the length of one frame is 0.04 seconds, 0.75 ÷ 0.04 = 18.75. From this, it can be seen that the next frame is 14:47:23:19. The next update time of the reference time code is 19 × 0.04 = 0.76, which is 14:47:23.76.

[0039] Once the next update time of the reference time code is found, the process waits until that time (step 314).Then, the process from step 315 onwards is the same as described above.

[0040] In step 314, wait until (b') in Figure 6(B). The time code value starting from that point is 14:47:23:19. Now, let's assume that the reference time code is set at the timing shown as "t1" in Figure 6(B). Then, the period during which the time code times match will be the range shown as "s" in Figure 6(B), and the period during which the time code times match can be extended.

[0041] As described above, if the time difference between the update time of the reference time code and the update time of the imaging time code is greater than half the time code update interval ("m" in Figure 6(B)), the reference time code is set between the update of the reference time code and the update of the imaging time code. By doing so, the period during which the time of the reference time code and the time of the imaging time code match can be set to be longer.

[0042] With this configuration, when the reference time code is set as the imaging time code, the period during which the reference time code and the imaging time code coincide can be made to be more than half the frame time, thereby preventing problems with subsequent video editing processes.

[0043] (Embodiment 2) In the first embodiment, the start time of the reference time code when the imaging time code is updated is calculated in step 308. However, the start time of the next reference time code may also be calculated. A flowchart for this case is shown in FIG. 4. Only the differences from FIG. 3 will be explained. In the flowchart of FIG. 3, the start time of the generated time code is calculated in step 308, but in FIG. 4, the end time of the reference time code is calculated (step 408). Then, the time difference between the reference time code and the imaging time code is calculated by subtracting the update time of the imaging time code from the update time of the reference time code (step 409). In this embodiment, the time difference between the update time of the reference time code and the update time of the imaging time code is "n" in FIGS. 6A and 6B. If the time difference is greater than half the time code update interval in step 410, proceed to step 311 (step 410-Y). Otherwise, proceed to step 314 (step 410-N). The processing from step 315 onwards is the same as described above.

[0044] In this way, the time difference between the image capture time code and the reference time code update timing may be calculated as the time from the next update timing of the reference time code. In this example, the next update time of the reference time code has already been calculated in step 408, so there is no need to perform step 313 in Figure 3.

[0045] (Embodiment 3) FIG. 5 is a flowchart of the third embodiment.

[0046] In the first and second embodiments, if the difference in update times is half the time code update interval, the system waits until the next reference time code update time before setting the reference time code as the imaging time code. When the update times of the two time codes are half the update interval, this means that the overlap between the imaging time code and the reference time code is exactly halfway (in FIGS. 6A and 6B, "m" and "n" are equal). In this case, regardless of the timing of setting, the period during which the reference time code and the imaging time code match is half the time code update interval.

[0047] Figure 5 is the flowchart of Figure 3 with the addition of step 511. In step 511, if the time difference between the update times of the two time codes is half the time code update interval, the time codes can be set immediately.

[0048] This allows the next reference time code or the next update timing of the imaging time code to be set without waiting.

[0049] (Other embodiments) The present invention can also be realized by executing the following process: software (programs) that realize the functions of the above-described embodiments are supplied to a system or device via a network or various storage media, and the computer (or CPU, MPU, etc.) of the system or device reads and executes the programs. [Explanation of symbols]

[0050] 101 Imaging device 107 Reference time code generation and acquisition section 108 Time Synchronization Unit 109 Clock Section 111 Frame rate acquisition unit 112 Imaging time code setting / acquisition section 115 Imaging time code update acquisition unit 118 Timecode update notification section 119 Reference time code update time acquisition section

Claims

1. In an imaging device having a function of adding an imaging time code to a moving image, a generation means for generating a reference time code; a setting means for adjusting the time of the imaging time code to the time of the reference time code; a first acquisition means for acquiring an update time of the reference time code; a second acquisition means for acquiring an update time of the imaging time code; The imaging device is characterized in that the setting means adjusts the time of the imaging time code to the time of the reference time code at a timing corresponding to the time difference between the update time of the reference time code and the update time of the imaging time code.

2. 2. The imaging device according to claim 1, wherein the update interval of the reference time code is the same as the update interval of the imaging time code.

3. The setting means If the time difference between the update time of the reference time code and the next update time of the imaging time code is smaller than half the update interval, 3. The imaging device according to claim 2, wherein the time of the imaging time code is adjusted to the time of the reference time code after the imaging time code has been updated and before the reference time code is next updated.

4. The setting means If the time difference between the update time of the reference time code and the next update time of the imaging time code is greater than half the update interval, 3. The imaging device according to claim 2, wherein the time of the imaging time code is adjusted to the time of the reference time code after the reference time code has been updated and before the imaging time code is next updated.

5. The setting means The imaging device according to claim 2, characterized in that, when the time difference between the update time of the reference time code and the update time of the next imaging time code is half the update interval, the time of the reference time code is adjusted to the time of the imaging time code regardless of the update timing.

6. a third acquisition means for acquiring time information from an external server; 2. The imaging device according to claim 1, wherein the generating means generates the reference time code based on time information acquired from the external server.

7. 1. A method for controlling an imaging device having a function of adding an imaging time code to a moving image, comprising: a generating step in which a generating means generates a reference time code; a setting step in which a setting means adjusts the time of the imaging time code to the time of the reference time code; a first acquisition step in which a first acquisition means acquires an update time of the reference time code; a second acquisition step in which a second acquisition means acquires an update time of the imaging time code; A control method characterized in that in the setting process, the time of the imaging time code is adjusted to the time of the reference time code at a timing corresponding to the time difference between the update time of the reference time code and the update time of the imaging time code.

8. Computer, In an imaging device having a function of adding an imaging time code to a moving image, a generation means for generating a reference time code; a setting means for adjusting the time of the imaging time code to the time of the reference time code; a first acquisition means for acquiring an update time of the reference time code; a second acquisition means for acquiring an update time of the imaging time code; The setting means is a computer program that causes the computer to function as an imaging device, characterized in that it aligns the time of the imaging time code with the time of the reference time code at a timing corresponding to the time difference between the update time of the reference time code and the update time of the imaging time code.

Images