JP2014155139A - Camera device and image record system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption of a camera device.SOLUTION: An image data generation unit 12 performs data storage processing 12B of storing image data 22 of each frame in a temporary storage memory 13, and data supply processing 12C of supplying the image data 22 in the temporary storage memory 13 to a CODEC 14. The image data generation unit 12 supplies only part of all frames output from an imaging unit 11 to the CODEC 14 by thinning out frames in at least one of the data storage processing 12B and data supply processing 12C. When M (M is a natural number of one or larger) sets of the image data 22 have been accumulated as an encoding target in the temporary storage memory 13, the image data generation unit 12 supplies the M sets of the image data to the CODEC 14. The image data generation unit 12 makes the CODEC 14 pause until M sets of the image data have been accumulated in the temporary storage memory 13.

Description

  The present invention relates to a camera device and an image recording system.

  In the surveillance camera system, a camera device captures a moving image by capturing an image at a predetermined frame rate. The camera device compresses the captured moving image and transmits the compressed data to the image recording device. In a general surveillance camera system, the image recording device is installed at a location different from the camera device, and therefore the camera device and the image recording device are connected via a communication network. There may be a case where a plurality of camera devices are provided for one image recording apparatus.

JP-A-9-270985 JP 2007-74128 A

  Generally, in order to obtain a moving image, the camera device always performs imaging. The frame rate is, for example, 30 fps (frames per second). However, image recording apparatuses are often operated with intermittent recording such as 10 fps. This is because the amount of recording data is suppressed by not recording data with low necessity for recording.

  In such a conventional configuration, the camera device performs processing such as imaging, compression, transmission, etc., even for frames that are not recorded. In other words, useless power is consumed in processing a frame that is not recorded.

  Note that Patent Document 1 discloses a video recording apparatus such as a video camera or a still camera. In this apparatus, the video signal output from the camera signal processing circuit is compressed for each predetermined section by an encoder / decoder and stored in a buffer memory. The HDD is put into a recording operation state only for a period necessary for recording the compressed data for each predetermined section stored in the buffer memory in the hard disk device (HDD). During other periods, the recording operation is suspended. According to this, it is stated that since the recording operation period in which the power consumption of the HDD is large is shortened, the power consumption and temperature rise caused by the HDD can be reduced.

  Patent Document 2 discloses a moving image data processing apparatus applied to a portable terminal such as a mobile phone or a digital camera. In this apparatus, the capture circuit captures moving image data for each frame, and the moving image data for one frame that has been captured by the capture circuit is encoded by the MPEG4 engine. The MPEG4 engine operates with an operation clock supplied from a clock control circuit. Here, the encoding processing time of moving image data for one frame by the MPEG4 engine is shorter than the processing time of moving image data for one frame by the capture circuit. The clock control circuit supplies the operation clock to the MPEG4 engine between the end of encoding of moving image data for one frame and the completion of capturing of moving image data for the next frame by the capture circuit. Stop. Thus, it is stated that low power consumption can be achieved.

  An object of this invention is to provide the technique which can reduce power consumption by the approach different from the technique of patent document 1,2. In view of the fact that the above problem is not limited to the surveillance camera system, the present invention also aims to provide a technique that can be applied to uses other than surveillance.

  The camera device according to the first aspect of the present invention performs an image capturing unit that captures an image at a predetermined frame rate and outputs an image signal, and a data generation process that generates image data of each frame from the image signal in a predetermined format. The image data generation unit, the temporary storage memory for storing the image data, and the image data for N frames (N is a natural number of 2 or more) are encoded as one set, and each generated set of encoded data is encoded And an encoder for outputting image data. The image data generation unit further performs data storage processing for storing the image data of each frame in the temporary storage memory, and data supply processing for supplying the image data in the temporary storage memory to the encoder. The image data generation unit supplies only a part of all frames output from the imaging unit to the encoder by thinning out the frame in at least one of the data storage process and the data supply process. To do. If the image data for M sets (M is a natural number of 1 or more) is stored as an encoding target in the temporary storage memory, the image data generation unit supplies the M sets of image data to the encoder. . The image data generation unit pauses the encoder until the M sets of image data are accumulated in the temporary storage memory.

  The camera device according to a second aspect of the present invention is the camera device according to the first aspect described above, wherein the M sets of image data are two or more sets of image data.

  A camera device according to a third aspect of the present invention is the camera device according to the first or second aspect described above, wherein the encoder has a processing speed faster than the predetermined frame rate of the imaging unit. Encode.

  A camera device according to a fourth aspect of the present invention is the camera device according to any one of the first to third aspects, wherein the image data generation unit is configured to store the image data of each frame. In addition, the time when the frame is acquired from the imaging unit is added as a time stamp.

  A camera device according to a fifth aspect of the present invention is the camera device according to any one of the first to fourth aspects described above, and further includes a processing unit that acquires the encoded image data. The image data generation unit pauses the processing unit together with the encoder.

  A camera device according to a sixth aspect of the present invention is the camera device according to any one of the first to fifth aspects, wherein the image data generation unit The frame is thinned out in the data supply process without thinning out the frame.

  An image recording system according to a seventh aspect of the present invention is a camera apparatus according to any one of the first to sixth aspects described above, and the encoded image data is acquired and recorded from the camera apparatus. An image recording apparatus.

  An image recording system according to an eighth aspect of the present invention is the image recording system according to the seventh aspect, wherein the camera device operates based on setting information given from the image recording device, The setting information includes at least one of a setting related to the frame decimation, the M setting value, and the N setting value.

  According to the first aspect described above, only a part of all the frames output from the imaging unit is supplied to the encoder by thinning out the frames. For this reason, a period in which image data is not supplied to the encoder occurs. Power consumption can be reduced by pausing the encoder during such a period. In particular, in the first aspect, M sets of image data are accumulated in the temporary storage memory, and then the M sets of image data are collected (in other words, the M sets of image data are set as one unit. ) By supplying to the encoder, the encoder is paused until the M sets of image data are accumulated in the temporary storage memory. For this reason, unlike the case where the temporary storage memory is not used, that is, when the image data is supplied to the encoder in real time while thinning out the frames, it is possible to avoid the pause period of the encoder from occurring. Considering the number of times and time spent on the overhead associated with starting and pausing the encoder, the intensive pause period can pause the encoder longer than the shredded pause period. As a result, a high power consumption reduction effect can be obtained.

  According to the second aspect described above, when the number of times and the time spent for the overhead associated with the start and stop of the encoder are taken into account, the pause period of the encoder is made longer than when image data is supplied to the encoder for each set. can do. For this reason, a higher power consumption reduction effect can be obtained.

  According to said 3rd aspect, compared with the case where encoding is performed with the same frame rate as imaging, encoding time can be shortened and, as a result, the rest period of an encoder can be lengthened more. For this reason, a higher power consumption reduction effect can be obtained.

  According to said 4th aspect, time information closer to imaging time can be added compared with the case where encoding time is employ | adopted as a time stamp, for example. In particular, considering that the encoder pauses until M sets of image data are accumulated, when the encoding time is employed as the time stamp, the deviation from the imaging time becomes large. Further, the amount of deviation also differs among the M sets of image data. If so, the usefulness as a recording is lowered. On the other hand, according to the 4th aspect, useful time information can be provided.

  According to said 5th aspect, the power consumption of a process part can also be reduced.

  According to said 6th aspect, even if it is a case where the change which increases the said setting value of N arises, it can respond quickly.

  According to the seventh aspect, since frame thinning is performed by the camera device, frame thinning can be omitted in the image recording device. Therefore, the processing load on the image recording apparatus can be reduced, and as a result, the power consumption of the image recording apparatus can be reduced. It is not prohibited to perform further frame thinning in the image recording apparatus.

  According to said 8th aspect, the setting (a setting change is also included) of a camera apparatus can be performed easily. For example, it is not necessary to manually set the camera device already installed. For example, it is particularly effective when the camera device is installed in a place where it is difficult to reach, when the camera device is installed at a location far from the image recording device, or when the number of camera devices is large. .

  The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

1 is a block diagram illustrating a configuration example of an image recording system according to Embodiment 1. FIG. 1 is a block diagram illustrating a configuration example of a camera device according to Embodiment 1. FIG. 6 is a diagram illustrating an operation example of a camera apparatus according to Embodiment 1. FIG. 6 is a block diagram illustrating another configuration example of the camera apparatus according to Embodiment 1. FIG. 6 is a diagram illustrating an operation example of a camera apparatus according to Embodiment 2. FIG. 10 is a diagram illustrating an operation example of a camera apparatus according to Embodiment 3. FIG. FIG. 10 is a diagram illustrating an operation example of a camera apparatus according to a fourth embodiment.

<Embodiment 1>
<Configuration of image recording system>
FIG. 1 shows a block diagram of an image recording system 1 according to the first embodiment. The image recording system 1 can be used for a surveillance camera system, for example. However, the use of the image recording system 1 is not limited to this.

  According to the example of FIG. 1, the image recording system 1 includes a camera device 2 and an image recording device 3. The number of camera devices 2 and image recording devices 3 is not limited to the example of FIG. That is, it is only necessary that one or more camera devices 2 and one or more image recording devices 3 are provided.

  In the image recording system 1, an image captured by the camera device 2 (here, a moving image) is transmitted to the image recording device 3 and recorded on a recording medium on the image recording device 3 side. The recording medium is, for example, a hard disk, and the image recording apparatus 3 is a recording apparatus having a built-in hard disk device (HDD), for example. The image recording device 3 may have a reproduction function.

  The camera device 2 and the image recording device 3 may be provided so as to communicate with each other, and the connection form is not limited to the example of FIG. Communication between the camera device 2 and the image recording device 3 can be realized by wired communication, wireless communication, or a combination thereof. The camera device 2 and the image recording device 3 may be connected via a public line, or may be connected via a dedicated communication line.

<Configuration of camera device>
FIG. 2 shows a block diagram of the camera device 2. According to the example of FIG. 2, the camera device 2 includes an optical system 10, an imaging unit 11, an image data generation unit 12, a temporary storage memory 13, a CODEC 14, a processing unit 15, a storage unit 16, and a communication. A unit 17, a recording medium 18, and a real-time output unit 19 are included.

  The optical system 10 includes a lens or the like, and guides light coming from the imaging range to the imaging unit 11.

  The imaging unit 11 includes, for example, a CCD type image sensor. The image sensor may be another type such as a CMOS type. The image sensor photoelectrically converts the light guided by the optical system 10 and outputs the obtained electrical signal.

  Here, a case where the imaging unit 11 includes an analog front end for digitally converting an analog signal output from the image sensor is illustrated. However, the analog front end may be included in the image data generation unit 12. The analog front end includes, for example, a CDS (correlated double sampling) circuit, an AGC (automatic gain adjustment) circuit, and an A / D converter, but is not limited to this example.

  A moving image is acquired by the imaging unit 11 continuously capturing images. The imaging frame rate is set in advance, and the set value may be fixed or variable. The imaging unit 11 outputs an imaging signal 21 related to the imaging result. The imaging signal 21 is digitized by an analog front end. In general, it is assumed that the output signal of the image sensor is an RGB signal, and the imaging signal 21 output from the imaging unit 11 is also an RGB signal.

  The image data generation unit 12 acquires the imaging signal 21 from the imaging unit 11, and performs data generation processing 12 </ b> A that generates image data 22 of each frame from the imaging signal 21. The data generation process 12 </ b> A includes a format conversion process for converting the imaging signal 21 into a format suitable for processing by the CODEC 14. For example, the imaging signal 21 composed of RGB components is converted into image data 22 composed of YUV components. Such component conversion can be performed by a known method. It is also possible to adopt a format other than YUV. The data generation process 12A may include various correction processes.

  The image data generation unit 12 further performs a data storage process 12B for storing the image data 22 of each frame in the temporary storage memory 13 and a data supply process 12C for supplying the image data 22 in the temporary storage memory 13 to the CODEC 14. . These processes 12B and 12C will be described in detail later.

  The image data generation unit 12 can be configured by a so-called DSP (Digital Signal Processor).

  The temporary storage memory 13 is composed of a RAM (Random Access Memory), and temporarily stores the image data 22 generated by the image data generation unit 12.

  In the example of FIG. 2, the CODEC 14 includes an encoder 14CO and a decoder 14DEC. The encoder 14CO encodes the image data 22 generated by the image data generation unit 12 by a predetermined method, and outputs encoded image data 24. At this time, the image data 22 for N frames (N is a natural number of 2 or more) is encoded as one set. In general, data is compressed by encoding. Contrary to the encoder 14CO, the decoder 14DEC decodes the encoded image data 24 according to the same method as the encoding.

  For example, the MPEG system can be used as the CODEC system for moving images. According to the MPEG system, the encoded image data 24 is one of an I picture, a P picture, and a B picture. However, the first frame of N frames is an I picture. In the MPEG system, a set of encoded image data 24 (here, N frames) obtained from a set of image data 22 (here, N frames) is called GOP (Group Of Picture). That is, 1 GOP is composed of N encoded frames.

  Here, in the camera apparatus 2, the decoder 14DEC is used as a local decoder when generating a B picture. Therefore, when the B picture is not used, in other words, when the GOP is composed of the I picture and the P picture, the decoder 14DEC may be omitted. In this case, the CODEC 14 may be referred to as an encoder 14CO.

  In the example of FIG. 2, the image data 22 in the temporary storage memory 13 is supplied to the CODEC 14 via the image data generation unit 12. On the other hand, it is also possible to adopt a configuration in which the image data 22 is directly transmitted from the temporary storage memory 13 to the CODEC 14 under the control of the image data generation unit 12.

  The processing unit 15 performs various processes in the camera device 2. For this reason, the processing unit 15 may be referred to as the overall processing unit 14 or the main processing unit 15. For example, the processing unit 15 acquires encoded image data 24 from the CODEC 14 and converts the image data 24 into communication data according to a communication protocol adopted by the communication unit 17. Further, the processing unit 15 performs a process for recording the encoded image data 24 on the recording medium 18, for example. Further, the processing unit 15 controls the camera device 2 in accordance with, for example, an instruction transmitted from the image recording device 3 (see FIG. 1).

  Here, the case where the process part 15 is comprised with a microcomputer is illustrated. In this case, the microcomputer executes each processing step (in other words, a procedure) described in the program. Thereby, the microcomputer functions as various means corresponding to the processing step, or various functions corresponding to the processing step are realized by the microcomputer. Note that some or all of the various means or various functions realized by the processing unit 15 can be realized by hardware.

  The storage unit 16 is provided so that the processing unit 15 is accessible, and stores programs and data used by the processing unit 15. The storage unit 16 provides a work area when the processing unit 15 executes the program. The storage unit 16 can be configured by using one or more storage devices such as a RAM, a ROM (Read Only Memory), and a rewritable and nonvolatile semiconductor memory.

  The communication unit 17 is an interface for the camera device 2 to communicate with the image recording device 3 (see FIG. 1), and is a so-called physical layer. The communication unit 17 is connected to the processing unit 15.

  The recording medium 18 is a removable medium such as an SD memory card. The recording medium 18 is accessible to the processing unit 15 by being attached to an I / O interface (not shown). Here, a case where the recording medium 18 is used for storing the encoded image data 24 is illustrated, but the present invention is not limited to this example. For example, the program executed by the processing unit 15 may be supplied by the recording medium 18. The recording medium 18 may be provided as necessary.

  Here, a case where the CODEC 14, the processing unit 15, and the I / O interface (not shown) for the recording medium 18 are integrated by SoC (System on a Chip) is illustrated. Further, the case where the integrated circuit has a power management function will be exemplified. According to the power management function, the CODEC 14, the processing unit 15, and the I / O interface for the recording medium 18 can be set together or independently, and a sleep mode (also referred to as a power saving mode) can be set. In the sleep mode, the circuit operation is suspended, or the power supply is further suspended, thereby reducing power consumption. In addition, when the I / O interface for the recording medium 18 is inactive, the operation of the recording medium 18 is also inactive, whereby the power consumption by the recording medium 18 can be reduced.

  The real-time output unit 19 generates a moving image signal for displaying the captured moving image in real time. The real-time output unit 19 can be realized by an NTSC (National Television System Committee) encoder, for example. In the example of FIG. 2, the image data 22 is input to the real-time output unit 19, but the image data 21 may be modified to be input. The real-time output unit 19 may be provided as necessary.

<Operation of camera device>
Hereinafter, more specific operations of the camera device 2 will be described. In order to make the description easier to understand, some non-limiting specific examples are assumed.

  The frame rate of imaging by the imaging unit 11 is 30 fps. In the image data generation unit 12, a series of processes of the data generation process 12A and the data storage process 12B are also executed at 30 fps. According to this, each frame acquired by the imaging unit 11 can be converted into image data 22 and stored in real time. However, the processing speed of the series of processes 12A and 12B may be higher than 30 fps. The encoding processing speed by the CODEC 14 is 30 fps. However, the encoding processing speed may be higher than 30 fps.

  One GOP is assumed to be composed of 15 frames. That is, the CODEC 14 encodes 15 frames of image data 22 as a set (N = 15).

  FIG. 3 shows an operation example of the camera device 2. In FIG. 3, the flow of processing is shown in the vertical direction, and the flow of time is shown in the horizontal direction. However, their illustration is schematic, and for example, illustration of a delay time caused by data transfer is omitted. Further, for the sake of explanation, an arbitrary frame among frames that are continuously captured is selected as the first frame, and consecutive frames are numbered in ascending order. The nth frame (n is a natural number of 1 or more) is denoted as “#n” in the drawing.

  In the example of FIG. 3, imaging is performed at 30 fps, and image data 22 is sequentially generated for all captured frames by the data generation process 12A. Then, the image data 22 generated by the data storage process 12B is sequentially stored in the temporary storage memory 13 (see FIG. 2).

  If 29 frames are accumulated in the temporary storage memory 13, only the odd-numbered frames are supplied to the CODEC 14 (see FIG. 2) as encoding targets by the data supply processing 12C. As a result, the CODEC 14 encodes the image data 22 for 15 frames, which are odd-numbered frames, as one set (corresponding to GOP in MPEG).

  When the data supply to the CODEC 14 is completed, the storage area where the image data 22 before the supply end frame is stored in the temporary storage memory 13 is released. The released storage area is used for storing newly generated image data 22. Thereby, the storage capacity of the temporary storage memory 13 can be suppressed. The storage area can be released after all 15 frames have been supplied to the CODEC 14. Alternatively, each time each frame is supplied to the CODEC 14, the storage area of the supply end frame and the even-numbered frame immediately before it may be released. According to the latter method, the storage capacity of the temporary storage memory 13 can be further suppressed.

  As described above, the image data generation unit 12 thins out the frames in the data supply process 12C, so that only a part of all the captured frames is supplied to the CODEC 14. For this reason, a period in which the image data 22 is not supplied to the CODEC 14 occurs. By suspending the CODEC 14 during such a period, power consumption can be reduced.

  In particular, a set of image data 22 to be encoded (here, image data 22 of 15 frames including odd-numbered frames) is accumulated in the temporary storage memory 13 and then the set of image data 22 is stored. (In other words, the M sets of image data as one unit) are supplied to the CODEC 14. Thereby, the CODEC 14 is suspended until the one set of image data 22 is accumulated in the temporary storage memory 13.

  Here, without using the temporary storage memory 13, it is also possible to supply the image data 22 to the CODEC 14 in real time while thinning out the frames. However, with this method, the pause period of the CODEC 14 occurs in small portions.

  On the other hand, according to the method illustrated in FIG. 3, the sum of the image data 22 for 15 frames is set as one unit, and switching between operation and suspension of the CODEC 14 is controlled in this unit. For this reason, it is possible to avoid a short break period that occurs when the operation and pause of the CODEC 14 are switched in units of one frame as described above. Considering the number of times and time spent on the overhead associated with the activation and deactivation of the CODEC 14, the CODEC 14 can be suspended longer in the intensive suspension period than in the chopped suspension period. As a result, a high power consumption reduction effect can be obtained.

  Further, since frame thinning is performed by the camera device 2, frame thinning can be omitted in the image recording device 3. For this reason, the processing load in the image recording apparatus 3 can be reduced, and as a result, the power consumption of the image recording apparatus 3 can be reduced. Note that it is not prohibited to perform further frame thinning in the image recording apparatus 3.

  The pause of the CODEC 14 can be realized, for example, by using the sleep mode of the CODEC 14. Specifically, the power management function of the CODEC 14 is set in advance so as to shift to the sleep mode when the encoding of the given image data 22 (here, the image data 22 for 15 frames) is completed. Then, the image data generation unit 12 cancels the sleep mode of the CODEC 14 by giving an interrupt control instruction 32 (see FIG. 2) to the CODEC 14 in the data supply process 12C. As a result, the CODEC 14 is activated and encoding is started. In this case, the control instruction 32 can be interpreted as a sleep release instruction, in other words, an activation instruction.

  Alternatively, for example, the pause and activation of the CODEC 14 may be controlled by the image data generation unit 12 controlling the supply of a clock, power, and the like to the CODEC 14. Specifically, the image data generation unit 12 determines whether or not the CODEC 14 is executing encoding, and gives a control instruction 32 to a clock circuit, a power circuit, a power supply path, and the like according to the determination result. In this case, the control instruction 32 can be interpreted as a supply ON instruction and a supply OFF instruction.

  Here, as illustrated in FIG. 4, the control instruction 32 may be given not only to the CODEC 14 but also to the processing unit 15. That is, the processing unit 15 may be suspended together with the CODEC 14. According to this, the power consumption of the processing unit 15 can also be reduced. As the pause control of the processing unit 15, the above-described various methods exemplified for the CODEC 14 can be applied. It is more preferable that the processing unit 15 can be activated by an interrupt from the communication unit 17 in order to ensure communication with the image recording apparatus 2.

  Although the case where the imaging frame is thinned out to ½ is illustrated above, the thinning amount (in other words, the thinning rate) is not limited to this. For example, a thinning amount such as 1/3 or 1/10 may be adopted. Although it is possible to thin out at unequal intervals, continuity in the entire moving image becomes better when thinned out at equal intervals as in the example of FIG.

  Settings relating to frame decimation (thinning amount, decimation interval, etc.) can be performed by directly operating a switch of the camera apparatus 2 or the like, but may be performed from the image recording apparatus 3. Specifically, setting information is transmitted from the image recording apparatus 3, and the processing unit 15 receives the setting information via the communication unit 17. Then, the processing unit 15 gives a setting instruction 35 (see FIG. 3) based on the setting information to the image data generation unit 12. For example, the processing unit 15 can write the received setting information to a register for that purpose, and the image data generation unit 12 can read the contents of the register to give the setting instruction 35 to the image data generation unit 12. is there.

  By providing the camera recorder 2 with settings relating to frame thinning (including setting changes) from the image recording device 3, the settings can be easily performed. For example, it is not necessary to manually set the camera device 2 that has already been installed. For example, when the camera device 2 is installed in a place where it is difficult to reach, when the camera device 2 is installed at a location far from the image recording device 3, or when the number of camera devices 2 is large, It is effective.

  Note that settings such as the number N of frames included in one set to be encoded may be given from the image recording apparatus 3.

  Here, it is more preferable to add a time stamp to the image data 22 of each frame in the data generation process 12A. In particular, in the camera device 2, the time when the image data generation unit 12 acquires a frame from the imaging unit 11 is used as the time stamp of the frame.

  According to this, time information closer to the imaging time can be added as compared with the case where, for example, the encoding time is adopted as the time stamp. In particular, considering that the CODEC 14 is suspended until a predetermined number of image data 22 is accumulated, when the encoding time is adopted as the time stamp, the deviation from the imaging time becomes large. The amount of deviation also differs between the image data 22 for one set of encoding targets (15 frames in the example of FIG. 3). If so, the usefulness as a recording is lowered. In contrast, useful time information can be provided by adopting the time when the image data generation unit 12 acquires the frame from the imaging unit 11 as a time stamp.

<Embodiment 2>
FIG. 5 shows an operation example of the camera apparatus 2 according to the second embodiment. FIG. 3 according to the first embodiment exemplifies a case in which one set of image data 22 is supplied to the CODEC 14 when one set (15 frames) of image data 22 to be encoded is accumulated.

  On the other hand, in the example of FIG. 5, when two sets (30 frames in this case) of image data 22 are accumulated as encoding targets in the temporary storage memory 13, the two sets of image data 22 are stored in the CODEC 14. To supply. Therefore, the CODEC 14 pauses until two sets of image data 22 are accumulated in the temporary storage memory 13. Therefore, in consideration of the number of times and time spent for the overhead associated with the activation and suspension of the CODEC 14, the pause period of the CODEC 14 is made longer than when the image data 22 is supplied to the CODEC 14 for each set as shown in FIG. Can do. As a result, a higher power consumption reduction effect can be obtained.

  Three or more frames may be accumulated in the temporary storage memory 13. Further, the number of sets M can be given to the camera device 2 in the same manner as the setting related to frame thinning.

<Embodiment 3>
FIG. 6 shows an operation example of the camera device 2 according to the third embodiment. In FIG. 3 according to the first embodiment, the case where the encoding processing speed by the CODEC 14 is the same as the frame rate of the imaging by the imaging unit 11 is illustrated.

  On the other hand, in the example of FIG. 6, the encoding by the CODEC 14 is processed at a speed twice as high as the imaging frame rate. For this reason, the encoding time can be shortened, and as a result, the pause period of the CODEC 14 can be lengthened. Thereby, a higher power consumption reduction effect can be obtained. Such an effect is not limited to the example of FIG. 6, and can be obtained if the processing speed of the CODEC 14 is faster than the imaging frame rate.

  Note that Embodiment 3 may be combined with Embodiment 2.

<Embodiment 4>
FIG. 7 shows an operation example according to Embodiment 4 of the camera device 2. In FIG. 3 according to the first embodiment, a case where frames are thinned out at the stage of supplying the image data 22 to the CODEC 14 is illustrated.

  On the other hand, in the example of FIG. 7, frames are thinned out at the stage where the image data 22 is stored in the temporary storage memory 13. When one set of image data 22 (15 frames in this case) is stored as an encoding target in the temporary storage memory 13, the one set of image data 22 is supplied to the CODEC 14. The effect similar to that of the first embodiment can be obtained by such frame thinning. Further, according to the fourth embodiment, the storage capacity of the temporary storage memory 13 can be suppressed.

  The fourth embodiment may be combined with one or both of the second and third embodiments.

  Here, as in the first embodiment, when thinning out frames in the data supply processing 12C without thinning out frames in the data storage processing 12B, the following effects are obtained. That is, since all the captured frames are stored in the temporary storage memory 13, it is possible to quickly cope with a change that increases the setting value of the number N of frames included in one set to be encoded.

<Modification 1>
In Embodiments 1 to 4, the case where the camera device 2 and the image recording device 3 are installed in different places and connected by a communication function has been illustrated. On the other hand, the camera device 2 and the image recording device 3 may be integrated. In this case, for example, the communication unit 17 (see FIG. 2) can be omitted.

  Further, the camera device 2 can be used alone. In this case, for example, the encoded image 24 may be stored in the recording medium 18. Even when the camera device 2 is used alone, for example, the communication unit 17 (see FIG. 2) can be omitted.

<Modification 2>
Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Image recording system 2 Camera apparatus 3 Image recording apparatus 11 Imaging part 12 Image data generation part 12A Data generation process 12B Data storage process 12C Data supply process 13 Temporary storage memory 14 CODEC
14 CO encoder 14 DEC decoder 15 processing unit 21 imaging signal 22 image data 24 encoded image data

Claims (8)

An imaging unit for imaging at a predetermined frame rate and outputting an imaging signal;
An image data generation unit that performs data generation processing for generating image data of each frame in a predetermined format from the imaging signal;
A temporary storage memory for storing the image data;
An encoder that encodes the image data of N frames (N is a natural number of 2 or more) as a set, and outputs the generated encoded image data of each set;
The image data generation unit
A data storage process for storing the image data of each frame in the temporary storage memory;
Further performing a data supply process for supplying the image data in the temporary storage memory to the encoder,
The image data generation unit supplies only a part of all frames output from the imaging unit to the encoder by thinning out the frame in at least one of the data storage process and the data supply process. And
If the image data for M sets (M is a natural number of 1 or more) is stored as an encoding target in the temporary storage memory, the image data generation unit supplies the M sets of image data to the encoder. ,
The image data generation unit pauses the encoder until the M sets of image data are accumulated in the temporary storage memory.
Camera device. The camera device according to claim 1,
The camera device, wherein the M sets of image data are two or more sets of image data. The camera device according to claim 1 or 2,
The encoder device performs the encoding at a processing speed higher than the predetermined frame rate of the imaging unit. The camera device according to any one of claims 1 to 3,
The image data generation unit is a camera device that adds, to the image data of each frame, a time stamp when the frame is acquired from the imaging unit. The camera device according to any one of claims 1 to 4, wherein:
A processing unit for acquiring the encoded image data;
The image data generation unit pauses the processing unit together with the encoder,
Camera device. The camera device according to any one of claims 1 to 5,
The image data generation unit is a camera device that thins out the frame in the data supply process without thinning out the frame in the data storage process. The camera device according to any one of claims 1 to 6,
An image recording system comprising: an image recording device that acquires and records the encoded image data from the camera device. The image recording system according to claim 7, wherein
The camera device operates based on setting information given from the image recording device,
The setting information includes
A setting for thinning out the frame;
The set value of M;
An image recording system including at least one of the N set values.

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