JP2017079392A - Radio photographing system and photographing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a user to take video from various angles and store it regardless of the position of the user.SOLUTION: A radio photographing system comprises a photographing device for taking video, and a recording device physically separated from the photographing device and recording the video taken by the photographing device. The photographing device transmits video data taken with a lens unit to the recording device by stream transmission (S16). The recording device wirelessly receives the video data transmitted by the photographing device (S23), and displays the received video data (S25). When recording instructions from a user are input in the state of the video being displayed, the recording device stores video data desired by the user from the received video data according to the input timing (S26 and S27).SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wireless photographing system and a photographing apparatus.

  A general camera (including a video camera) integrally includes a photographing unit and a recording unit.

  On the other hand, as disclosed in Japanese Patent Application Laid-Open No. 2013-168839 (Patent Document 1), an imaging system in which a lens unit and a main unit can communicate wirelessly has been proposed. In this imaging system, it is disclosed that a monitoring image of a lens unit is displayed on an image display unit of a main unit and an imaging operation is transmitted to the lens unit by operating an operation unit of the main unit. It is disclosed that an image picked up by a lens unit is transferred to a main unit and recorded in a recording device connected to the main unit.

  Japanese Unexamined Patent Application Publication No. 2007-67456 (Patent Document 2) discloses a video photographing device that distributes a video photographed by a normal camera to a user terminal. It is disclosed that a video can be taken with a favorite shutter chance while watching the video.

JP 2013-168839 A JP 2007-67456 A

  As described above, Patent Document 1 proposes an imaging system that can be used by physically separating the lens unit and the main unit. However, in the system of Patent Document 1, when the release switch of the main unit is pressed, an image (still image) taken by the lens unit is transferred to the main unit. Also in the system of Patent Document 2, an image captured by a camera is distributed in response to a captured signal from a user terminal.

  As described above, in a system that receives a photographing signal from a user terminal and transmits a photographed image, the device (main body unit) operated by the user and the photographing device (lens unit) are arranged far apart. In such a case, since the timing at which the user inputs the shooting instruction and the timing at which the shooting signal is received on the shooting device side are shifted, complicated delay processing or the like is required on the shooting device side. Moreover, even if the delay process or the like is performed, the user cannot always acquire a desired image.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a wireless shooting system capable of shooting and storing videos of various angles regardless of the position of the user. It is to provide a photographing apparatus.

  A wireless imaging system according to an aspect of the present invention includes an imaging device that captures an image, and a recording device that is physically separated from the imaging device and records an image captured by the imaging device. The imaging device includes a lens unit and wireless transmission means for streaming transmission of video data captured by the lens unit to a recording device. The recording apparatus includes: a wireless receiving unit that wirelessly receives the video data transmitted from the wireless transmitting unit; a display unit that displays the video data received by the wireless receiving unit; and a video displayed on the display unit by a user. Operating means for receiving the recording instruction, and storage means for storing user-desired video data from the video data received by the wireless receiving means in accordance with the input timing of the recording instruction.

  Preferably, the imaging device includes a determination unit that analyzes the communication environment and determines a communication condition with the recording device according to the analysis result, and a notification unit that notifies the recording device of the communication condition determined by the determination unit. In addition. Accordingly, the wireless reception unit of the recording apparatus receives the video data transmitted from the wireless transmission unit based on the communication condition notified by the notification unit.

  Preferably, the communication condition includes at least one of a bandwidth used for wireless communication, a type of carrier wave modulation method used for wireless communication, and a coding rate. In this case, the wireless transmission means wirelessly transmits the video data to the recording apparatus using the orthogonal frequency division multiplexing method under the communication conditions determined by the determination means.

  It is desirable that each of the photographing apparatus and the recording apparatus includes a plurality of communication antennas. In this case, it is desirable that the wireless transmission unit transmits video data by the MIMO method, and the determination unit determines the number of antennas used for wireless communication among a plurality of communication antennas as one of the communication conditions.

  The recording device may receive video data from a plurality of photographing devices. In this case, it is desirable that the storage unit of the recording apparatus stores the video data in association with the index data including the identification information of the photographing apparatus.

  The index data may further include at least one of an installation location and a category of the imaging device.

  Preferably, the connection between the photographing apparatus and the recording apparatus is established by transmitting and receiving the respective identification information.

  An imaging apparatus according to another aspect of the present invention is an imaging apparatus capable of wireless communication with a recording apparatus, analyzes a lens unit for capturing an image and a communication environment, and according to the analysis result A determination unit configured to determine a communication condition with the recording apparatus; and a notification unit configured to notify the recording apparatus of the communication condition determined by the determination unit. In addition, wireless transmission means is provided that streams the video data captured by the lens unit to the recording device based on the communication conditions determined by the determination means.

  According to the present invention, videos of various angles can be taken and stored regardless of the position of the user.

It is a figure which shows typically the structure of the radio | wireless imaging system which concerns on embodiment of this invention. It is a block diagram which shows the structure of the imaging device in embodiment of this invention. It is a functional block diagram which shows the function structure of the communication control part of the imaging device in embodiment of this invention. 1 is a block diagram illustrating a configuration of a recording apparatus according to an embodiment of the present invention. It is a flowchart which shows the outline | summary of the radio | wireless imaging process performed in the radio | wireless imaging system in embodiment of this invention. It is a flowchart which shows a communication condition determination process. It is a flowchart which shows the congestion condition analysis process included in the communication condition determination process of FIG. It is a flowchart which shows the usage condition detection process of each zone | band included in the congestion condition analysis process of FIG. It is a flowchart which shows the bandwidth determination process included in the communication condition determination process of FIG. It is a figure which shows the structural example of the data table which matched the congestion level and the bandwidth to be used. It is a flowchart which shows the communication distance analysis process included in the communication condition determination process of FIG. It is a flowchart which shows the radio wave intensity detection process included in the communication distance analysis process of FIG. It is a flowchart which shows the antenna number determination process included in the communication condition determination process of FIG. It is a figure which shows the structural example of the data table which matched distance level and the number of antennas to be used. It is a flowchart which shows the noise level analysis process included in the communication condition determination process of FIG. It is a flowchart which shows the signal distortion detection process included in the noise level analysis process of FIG. It is a flowchart which shows the modulation system determination process contained in the communication condition determination process of FIG. It is a figure which shows the structural example of the data table which matched the noise level, the kind of modulation system to be used, and a code rate. It is a flowchart which shows the compression system determination process of FIG. It is a figure which shows notionally the form which distributes and transmits the divided | segmented video data to each usable band group. It is a figure which shows typically the structure of the radio | wireless imaging system which concerns on the modification 1 of embodiment of this invention. It is a figure which shows typically the structure of the radio | wireless imaging system which concerns on the modification 2 of embodiment of this invention. FIG. 10 is a diagram schematically showing an example of a screen displayed on the touch panel of the recording device in Modification 2 of the embodiment of the present invention. 10 is a flowchart showing video data storage processing executed by a recording apparatus in Modification 2 of the embodiment of the present invention. FIG. 16 is a diagram illustrating an example of a data structure of index data stored in association with each saved data in Modification 2 of the embodiment of the present invention. 10 is a flowchart illustrating target device setting processing executed by the recording apparatus in Modification 2 of the embodiment of the present invention.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  An imaging system according to an embodiment of the present invention will be described.

<About configuration>
FIG. 1 is a diagram showing a schematic configuration of a wireless photographing system 1 according to the present embodiment. Referring to FIG. 1, the wireless photographing system 1 includes a photographing device 10 that photographs a video, and a recording device 20 that can wirelessly communicate with the photographing device 10. Unlike a general camera (including a video camera), the photographing apparatus 10 does not include a nonvolatile storage unit for storing video (still images or moving images). The video captured by the imaging device 10 is wirelessly streamed to the recording device 20, and a part of the video (still image or moving image) is stored in the recording device 20. The recording device 20 may be a device dedicated to video recording used for communication with the imaging device 10 or may be realized by an information processing terminal (for example, a tablet terminal or a mobile phone) that can be carried by the user.

  The radio imaging system 1 employs an orthogonal frequency division multiplexing (OFDM) as a video radio communication system. As a result, high-quality video can be communicated at high speed. Configuration examples of the photographing apparatus 10 and the recording apparatus 20 will be described below.

(Configuration of the photographing device)
FIG. 2 is a block diagram illustrating a configuration example of the photographing apparatus 10. The photographing apparatus 10 includes a lens unit 11, a control unit 12, and a wireless transmission unit 13. In FIG. 2, the flow of the video signal is indicated by a solid arrow, and the flow of information other than the video or the control signal is indicated by a dashed arrow.

  The lens unit 11 includes, for example, a lens as an optical system element, and an image sensor as an electronic system element. The optical system element may include a diaphragm mechanism.

  The control unit 12 controls each unit of the photographing apparatus 10 and performs various arithmetic processes. The control unit 12 is realized by a processor including the memory 19, for example. Various programs and data are stored in the memory 19.

  In the photographing apparatus 10, video (moving image) data photographed by the lens unit 11 is sent to the wireless transmission unit 13 as it is. That is, unlike a normal camera or video camera, the photographing apparatus 10 does not have an operation button for acquiring a still image and an image storage unit for storing a still image or a moving image. Note that the photographing apparatus 10 may include an operation unit for adjusting the diaphragm mechanism and the like, a display unit for displaying an image for confirming the photographing range, and the like.

  The wireless transmission unit 13 includes a compression unit 14, a MIMO (Multiple-Input and Multiple-Output) wireless unit 15, a communication control unit 17, and a storage unit 18.

  The compression unit 14 compresses the video data and outputs it to the MIMO radio unit 15. The compression unit 14 has a function of performing both lossless compression (lossless) and lossy compression (lossy). The compression unit 14 compresses the video data using any one of these compression methods.

  For example, eight communication antennas 16a, 16b,..., 16h are provided in the MIMO wireless unit 15. The MIMO radio unit 15 employs an orthogonal frequency division multiplexing (OFDM) as described above. As a carrier wave modulation method, a quadrature amplitude modulation method is adopted, and for example, it is possible to select from four types of 256QAM, 64QAM, 16QAM, and QPSK. As the amount of data that can be transmitted simultaneously increases in the order of QPSK, 16QAM, 64QAM, and 256QAM, the possibility of transmission errors increases. Note that the types of modulation schemes are not limited to these.

  The communication control unit 17 controls the compression unit 14 and the MIMO radio unit 15 for communication with the recording device 20. The storage unit 18 stores various programs and data. The communication control unit 17 is realized by a computer such as a microcomputer, for example, and performs various types of information processing based on a program stored in the storage unit 18. The functional configuration of the communication control unit 17 is shown in FIG.

  Referring to FIG. 3, communication control unit 17 includes, as its functional configuration, environment analysis unit 31, communication condition determination unit 32, video analysis unit 33, compression method determination unit 34, and notification processing unit 35. Including.

  The environment analysis unit 31 analyzes the communication environment at least at the start of video transmission. Specifically, the other wireless communication congestion status, communication distance, and noise level are analyzed. The congestion status of other wireless communication is analyzed by detecting whether or not each band (for example, all 8 bands) used for video data communication is used in other wireless communication. The communication distance with the recording apparatus 20 that is the communication partner is analyzed by detecting the radio wave intensity during communication with the recording apparatus 20. The noise level generated in the wireless communication environment is analyzed by detecting the degree of signal distortion during communication with the recording device 20.

  Note that the communication antennas 16a, 16b,..., 16h may be used for measurement of the communication environment, or a measurement antenna 16m (FIG. 2) may be separately provided for communication environment measurement.

  Based on the analysis result of the environment analysis unit 31, the communication condition determination unit 32 determines a communication condition with the recording device 20, that is, a condition to be ensured when transmitting video data to the recording device 20. Specifically, the bandwidth used for wireless communication is determined based on the congestion status of other wireless communication. Further, the number of antennas used for wireless communication among the communication antennas 16 a to 16 h is determined based on the communication distance, that is, the radio wave intensity with the recording device 20. Furthermore, based on the noise level generated in the wireless communication environment, the type of carrier wave modulation method used for wireless communication and the coding rate are determined. In the present specification, a combination of a modulation scheme type and a coding rate may be simply referred to as a “modulation scheme”.

  The video analysis unit 33 inputs video data sent from the lens unit 11 and analyzes the video to be transmitted. Specifically, the video resolution, color information, and frame rate are analyzed. These analyzes can be realized by a known method. Note that if the resolution, color information, and frame rate of the captured video are determined by the settings on the lens unit 11 side, the video analysis unit 33 is not necessary.

  The compression method determination unit 34 determines the video compression method (lossless or lossy) in the compression unit 14 based on the analysis result of the video analysis unit 33 and the determination result of the communication condition determination unit 32. Specifically, the required transmission rate is calculated from the video analysis result, and the compression method is determined by comparing the calculated transmission rate with the transmission capacity obtained from the communication condition determined by the communication condition determining unit 32. judge.

  Note that the analysis result of the video analysis unit 33 may also be used for the determination of the communication condition in the communication condition determination unit 32 (imaginary line in FIG. 3).

  The notification processing unit 35 performs processing for notifying the recording device 20 of the determination result of the communication condition determination unit 32 and the determination result of the compression method determination unit 34.

  In the present embodiment, the functions of the environment analysis unit 31, the communication condition determination unit 32, the video analysis unit 33, the compression method determination unit 34, and the notification processing unit 35 illustrated in FIG. For example, the computer is realized by executing software stored in the storage unit 18. However, at least one of these functional units may be realized by hardware.

(Configuration of recording device)
FIG. 4 is a block diagram illustrating a configuration of the recording apparatus 20. The recording device 20 includes a wireless reception unit 21, a control unit 22, an operation unit 24, a display unit 25, a timer unit 26, a drive device 27, and an image storage unit 28. Also in FIG. 4, the flow of the video signal is indicated by a solid arrow, and the flow of information other than the video or the control signal is indicated by a dashed arrow.

  The wireless reception unit 21 includes a MIMO wireless unit 43, an expansion unit 45, a communication control unit 46, and a storage unit 47.

  The MIMO radio unit 43 has a function similar to that of the MIMO radio unit 15 of the photographing apparatus 10, and is provided with, for example, eight communication antennas 44a, 44b,. That is, the number of communication antennas of the imaging device 10 and the number of communication antennas of the recording device 20 are the same. The MIMO radio unit 43 may also be provided with a measurement antenna 44m separately for measuring the communication environment.

  The decompression unit 45 decompresses the video signal received by the MIMO wireless unit 43 and outputs it to the control unit 22. The decompression unit 45 has a function of decompressing both video data compressed by the lossless compression method and video data compressed by the lossy compression method.

  The communication control unit 46 controls the MIMO wireless unit 43 and the expansion unit 45 for communication with the imaging apparatus 10. The storage unit 47 stores various programs and data. The communication control unit 46 performs various information processing based on programs stored in the storage unit 47. The communication control unit 46 operates the MIMO wireless unit 43 according to the communication conditions notified from the imaging device 10. In addition, the decompression unit 45 is operated according to the compression method notified from the photographing apparatus 10.

  The control unit 22 controls each unit of the recording apparatus 20 and performs various arithmetic processes. The control unit 22 is realized by a processor including the memory 29, for example. Various programs and data are stored in the memory 29. The operation unit 24 receives an instruction from the user. The display unit 25 displays various information such as video. The operation unit 24 and the display unit 25 may be configured as an integrated touch panel 23. The clock unit 26 is a clock that clocks time. The drive device 27 reads and writes data and programs from a removable recording medium (not shown). The image storage unit 28 stores only video data desired by the user among the video data received by the wireless reception unit 21. The image storage unit 28 is a nonvolatile storage device.

<About operation>
FIG. 5 is a flowchart showing an outline of wireless imaging processing executed in the wireless imaging system 1 according to the present embodiment. The video transmission process performed by the photographing apparatus 10 is realized by the control unit 12 reading and executing a program stored in the memory 19. The video recording process performed by the recording device 20 is realized by the control unit 22 reading and executing a program stored in the memory 29. When the recording device 20 is not a device dedicated to video recording, the video recording process is started when the wireless shooting mode is selected in the recording device 20. It is assumed that the photographing apparatus 10 is in a standby state at the start of the wireless photographing mode.

  Referring to FIG. 5, first, in the recording device 20, setting processing of a device to be connected (hereinafter referred to as “target device”) is performed based on an instruction from the user (step S (hereinafter abbreviated as “S”)). 20). As in the present embodiment, when the relationship between the imaging device 10 and the recording device 20 is 1: 1, the imaging device 10 is selected as the target device. At this time, identification information (ID) of the selected photographing apparatus 10 is temporarily stored in the internal memory 29. When the target device is set, the control unit 22 notifies its identification information (ID) to the device (S21).

  When receiving the identification information, the imaging device 10 determines that the recording device 20 specified by the identification information is the target device (S11). Thereby, a connection is established between the imaging device 10 and the recording device 20.

  When the connection is established, the photographing apparatus 10 performs communication condition determination processing and compression method determination processing (S12). These determination processes will be described later with a subroutine.

  When the determination of the communication condition and the compression method ends, the notification processing unit 35 notifies the recording device 20 of the determination result (S13). In addition, the communication control unit 17 sends a command signal for instructing the compression method to the compression unit 14 and sends a command signal for instructing the communication method to the MIMO wireless unit 15.

  When the communication method and the compression method are determined, the photographing apparatus 10 starts photographing (S14). As a result, video data captured by the lens unit 11 is output to the wireless transmission unit 13. Accordingly, the compression unit 14 compresses the video data by the compression method determined in S12 (S15), and the MIMO wireless unit 15 performs stream transmission of the compressed video data according to the communication conditions determined in S12. (S16).

  In the recording device 20, the MIMO wireless unit 43 receives the notification of the communication condition and the compression method notified from the imaging device 10 in S13 (S22). The communication control unit 46 instructs the decompression unit 45 on the decompression method corresponding to the compression method, and instructs the MIMO radio unit 43 on the communication method.

  After the communication method and the expansion method are determined in the recording device 20, the MIMO wireless unit 43 wirelessly receives the video data transmitted from the MIMO wireless unit 15 of the imaging device 10 in accordance with the communication condition notified in S22 ( S23). Further, the received video data is decompressed by the decompression method corresponding to the compression method notified in S22 (S24). The expanded video data is temporarily recorded in the internal memory 29 and displayed on the touch panel 23 (display unit 25) (S25). Thereby, the user can check the video (monitoring image) captured by the physically separated imaging device 10 on the touch panel 23 of the recording device 20.

  With the captured video displayed on the touch panel 23, the control unit 22 determines whether or not a recording instruction is input from the user (S26). If there is no recording instruction, the display of the captured video on touch panel 23 is continued (NO in S26). When a recording instruction is input from the user while the captured video is displayed (YES in S26), the image (still image or moving image) displayed when the recording instruction is input is stored in the image storage unit 28. Save (S27). Specifically, the control unit 22 extracts video data corresponding to the input timing of the recording instruction from the video data temporarily recorded in the internal memory 29 and outputs the video data to the image storage unit 28.

  The video data (image) stored in the image storage unit 28 is preferably stored in association with the index data. The index data includes, for example, the ID of the photographing apparatus 10, the photographing date and time, and the storage location (address) of the video data. The shooting date and time is obtained based on a signal from the time measuring unit 26 provided in the recording device 20.

  Note that the recording device 20 continues to receive and display video data until the user gives an instruction to end the wireless shooting mode. Therefore, during the wireless shooting mode, the user can take any number of photos at any time. When an instruction to end the wireless shooting mode is input from the user, a shooting end signal is transmitted from the recording device 20 to the shooting device 10. When receiving the shooting end signal, the shooting device 10 ends the shooting process.

  According to this embodiment, since the stream video is wirelessly received by the recording device 20, the user can take a picture or a video while viewing the video. That is, the user can save a desired still image or moving image in his / her own device (the image storage unit 28) in the recording device 20 at hand even if the photograph is at a distant place. Therefore, a complicated delay process is not required as compared with a system that obtains video data by transmitting a photographing instruction signal to the photographing device 10 far from the recording device 20. As a result, the video desired by the user can be reliably stored.

  When recording a moving image in the recording device 20, a recording stop instruction may be received from the user after the recording instruction, or video data for a preset time may be stored.

  As described above, in order to enable wireless transmission of high-quality video data from the imaging device 10 even when the imaging device 10 and the recording device 20 are far apart, as described above, the communication conditions in the imaging device 10 Then, a compression method determination process (S12) is performed. These processes will be described in detail below.

(Communication condition judgment processing)
FIG. 6 is a flowchart showing an outline of the communication condition determination process.

  In the communication condition determination process, the environment analysis unit 31 performs a congestion state analysis process (S101), a communication distance analysis process (S103), and a noise level analysis process (S105). These are preferably performed in parallel. The communication condition determination unit 32 executes a bandwidth determination process (S102) based on the congestion state analysis process, executes an antenna number determination process (S104) based on the communication distance analysis process, and based on the noise level analysis process. A modulation system determination process (S106) is executed.

  FIG. 7 is a flowchart showing the congestion situation analysis process. The environment analysis unit 31 determines the congestion level by executing the usage status detection process for each band (S111) (S112). The detection process of S111 is shown in FIG.

  Referring to FIG. 8, first, MIMO radio section 15 is set to the reception mode (S121), and the signal usage status is detected for each band. That is, the reception mode of a specific band is set (S122), and the presence / absence of a signal in that band, that is, the presence / absence of a collision is confirmed (S123). If there is a signal, the environment analysis unit 31 determines that the band is used, and if there is no signal, determines that the band is not used (S124). Such processing is repeated for the target band, and the congestion status of all the target bands is analyzed. Note that it is desirable to notify the recording device 20 of the determined usage status of each band.

  The congestion level is determined, for example, in eight stages according to the amount of other wireless communication. For example, if there is a collision in 7 out of 8 bands and only one band is unused, the congestion level is 8. If there is no signal in all bands and all 8 bands are unused, the congestion level is 1. Such level determination can be realized, for example, by using a predetermined data table (not shown). Here, for ease of understanding, it is assumed that the congestion level is determined according to the number of continuously unused bands. Specifically, when channel 1, channels 3 and 4, and channels 6 to 8 are unused, channels 6 to 8 have the largest number. In this case, it is determined that the three consecutive bands are unused and the congestion level is 6.

  When the congestion situation analysis process ends, a bandwidth determination process (S102) is performed.

  FIG. 9 is a flowchart showing the bandwidth determination process. First, the communication condition determination unit 32 reads table information stored in advance in the storage unit 18 (S131). An example of the table information is shown in FIG. FIG. 10 is a diagram illustrating a structure example of a data table in which a congestion level is associated with a bandwidth to be used. In FIG. 10, the number of channels corresponding to the bandwidth is also shown for reference. In this embodiment, an example in which the bandwidth of one channel is 20 MHz is shown, but the present invention is not limited to this. That is, the bandwidth determination process can be applied to a standard in which the bandwidth of one channel is 40 MHz or 80 MHz, for example.

  Based on the table information, the communication condition determination unit 32 determines the bandwidth to be used (S132). For example, when the congestion level is 1 and all 8 bands are usable, the bandwidth to be used is determined as the maximum value (for example, 160 MHz). When the congestion level is 6 and three consecutive bands are unused, the bandwidth to be used is determined as 60 MHz.

  It should be noted that it is desirable to select a channel that can reduce interference with other wireless communications except when the congestion level is 1 and all 8 bands are usable.

  When the bandwidth is determined and the channel to be used is determined, it is preferable that the communication condition determination unit 32 confirms whether the determined channel (bandwidth) and bandwidth are appropriate. Specifically, after the determined channel and bandwidth are notified to the recording apparatus 20, pilot data is transmitted to the recording apparatus 20 using the determined channel (S133). At this time, an amount of pilot data corresponding to the determined bandwidth is transmitted. The pilot data is known data. The recording device 20 calculates a BER (Bit Error Rate) of the received pilot data and returns it to the imaging device 10.

  The communication condition determination unit 32 determines the communication status by comparing the received BER with a predetermined reference value (S134). Thereby, the validity of the determined channel and bandwidth is determined. Note that one antenna such as an antenna for environment measurement may be used for transmission / reception of pilot data at the time of determining validity. Also, the pilot data modulation method may be fixed. In this case, a combination of QPSK and coding rate 1/2, which has the highest noise tolerance, can be adopted as a modulation method at the time of transmitting pilot data.

  If the BER exceeds the reference value (“NG” in S134), it is desirable to return to S132 and change the bandwidth to be used or the channel to be used. Note that it is desirable to change the bandwidth or channel to be used even when a collision with other wireless communication occurs in the band that is in use after the start of communication.

  Specifically, if there are other usable band groups, the band may be changed to another band group regardless of whether or not the bandwidth is the same. For example, when channels 1, 5, and 8 are used in other wireless communication, usually three bands of channels 2 to 4 are used. However, when a collision occurs in channel 3, the band to be used is set to the channel. Change to 6-7.

  Alternatively, the bandwidth may be narrowed so that the channel adjacent to the channel in use is not used. For example, when channels 1 and 6 are used in other wireless communication, usually four bands of channels 2 to 5 are used. However, in order to reduce interference with other wireless communication, the bandwidth is narrowed. The channel 3 to 4 may be changed to two bands.

  FIG. 11 is a flowchart showing the communication distance analysis process. The environment analysis unit 31 determines the distance level to the recording device 20 by executing a radio wave intensity detection process (S141) (S142). The detection process of S141 is shown in FIG.

  Referring to FIG. 12, first, the environment analysis unit 31 requests the recording device 20 to transmit pilot data (S151). When the recording device 20 transmits pilot data in response to the request, the MIMO radio unit 15 receives the pilot data (S152). The environment analysis unit 31 measures the radio field intensity at that time as a voltage level (S153). Note that the number of antennas (one), modulation scheme (QPSK), and bandwidth (1ch) used for transmission / reception of pilot data in the environment analysis are all fixed. Note that the band used at this time is selected from the bands determined to be usable in S124 of FIG.

  The distance level to the recording device 20 is determined, for example, in four stages according to the magnitude of the radio wave intensity. The level determination here can also be realized by using a predetermined data table (not shown), for example.

  When the communication distance analysis process ends, an antenna number determination process (S104) is performed.

  FIG. 13 is a flowchart showing the antenna number determination process. First, the communication condition determination unit 32 reads table information stored in advance in the storage unit 18 (S161). An example of the table information is shown in FIG. FIG. 14 is a diagram illustrating a structure example of a data table in which a distance level is associated with the number of antennas to be used.

  Based on the table information, the communication condition determination unit 32 determines the number of antennas to be used (S162). For example, if the radio wave intensity is relatively high and the distance level is 1 (close), the number of antennas to be used is 8 (all), and if the radio wave intensity is relatively low and the distance level is 4 (far), it is used. The number of antennas is one. Thus, the reason why the number of antennas used is reduced as the communication distance is longer is that the output per antenna is reduced as the number of antennas used is increased. In other words, in this embodiment, the number of antennas to be used is determined according to the radio field intensity, so that the output is ensured and the video data can be reliably transmitted.

  When the number of antennas is determined, it is desirable that the communication condition determination unit 32 again confirms whether the determined number of antennas is appropriate. Specifically, after notifying the recording device 20 of the determined number of antennas, pilot data is transmitted to the recording device 20 with an antenna output corresponding to the determined number (S163). The recording device 20 calculates the BER of the received pilot data and returns it to the imaging device 10.

  Even when the validity of the number of antennas is confirmed, one antenna such as an environment measurement antenna is used for transmission and reception of pilot data, and the output power of the antenna corresponds to the determined number of antennas in a pseudo manner. It is desirable to set the power level. The modulation scheme and bandwidth used for transmission / reception of pilot data are fixed. The bandwidth may be 20 MHz for 1ch, for example.

  The communication condition determination unit 32 determines the communication status by comparing the BER received from the recording device 20 with a predetermined reference value (S164). Thereby, the validity of the determined number of antennas is determined. If the BER received from the recording device 20 exceeds the reference value (“NG” in S164), it is desirable to return to S162 and change the number of antennas to be used.

  FIG. 15 is a flowchart showing the noise level analysis process. The environment analysis unit 31 determines a noise level by executing a signal distortion detection process (S171) (S172). The detection process of S171 is shown in FIG.

  Referring to FIG. 16, first, the environment analysis unit 31 requests the recording device 20 to transmit pilot data (S181). When the recording device 20 transmits pilot data in response to the request, the MIMO wireless unit 15 receives the pilot data (S182). The environment analysis unit 31 measures the distortion of the pilot data by a known method (S183).

  The noise level is determined, for example, in 8 stages according to the amount of distortion. The level determination here can also be realized by using a predetermined data table (not shown), for example.

  When the noise level analysis process is completed, a modulation scheme determination process (S106) is performed.

  FIG. 17 is a flowchart showing the modulation scheme determination processing. The communication condition determination unit 32 first reads table information stored in advance in the storage unit 18 (S191). An example of the table information is shown in FIG. FIG. 18 is a diagram illustrating a structure example of a data table in which a noise level is associated with a modulation scheme type and a coding rate.

  Based on the table information, the communication condition determination unit 32 determines the type of modulation scheme to be used and the coding rate (S192). For example, if the signal distortion is small and the noise level is 2, the modulation method is 256QAM and the coding rate is 2/3. If the signal distortion is large and the noise level is 8, the modulation method is QPSK and the coding rate is ½.

  Once the modulation scheme type and coding rate are determined, it is desirable that the communication condition determination unit 32 confirms whether or not the determined modulation scheme is appropriate. Specifically, after notifying the recording apparatus 20 of the determined modulation scheme, the pilot data modulated by the determined modulation scheme is transmitted to the recording apparatus 20 (S193). The recording device 20 calculates the BER of the received pilot data and returns it to the imaging device 10. Also at this time, the antenna used for transmission / reception of pilot data is one antenna such as an antenna for environment measurement, and the bandwidth used for transmission / reception of pilot data is fixed.

  The communication condition determination unit 32 determines the communication status by comparing the BER received from the recording device 20 with a predetermined reference value (S194). Thus, the validity of the determined modulation scheme type and coding rate is determined. If the BER received from the recording device 20 exceeds the reference value (“NG” in S194), it is desirable to return to S192 and change the type and coding rate of the modulation scheme to be used.

  In the above description, when the validity of each condition is detected, pilot data is transmitted and received for each condition. However, the validity of a plurality of conditions may be detected by transmitting and receiving pilot data once. .

  Also, when analyzing the communication environment, the measurement of radio wave intensity (FIG. 12) and the measurement of noise level (FIG. 16) may be realized by transmitting and receiving pilot data once.

  Moreover, as shown in FIG. 6, although the determination process of multiple conditions was performed in parallel, these may be performed in series. In this case, it is desirable to preferentially determine the bandwidth.

(Compression condition judgment processing)
FIG. 19 is a flowchart showing compression method determination processing.

  In the compression method determination process, first, the video analysis unit 33 analyzes the input video (S201). Based on the analysis result, the compression method determination unit 34 calculates a necessary transmission rate (S202). Specifically, the necessary transmission rate is calculated as “horizontal resolution × vertical resolution × color information × frame rate”.

  Next, the compression method determination unit 34 calculates a transmission capacity (S203). Specifically, the transmission capacity is calculated as “number of antennas × number of channels × number of bits per carrier × number of bits per symbol × coding rate / symbol length”.

  Thereafter, the compression method determination unit 34 determines whether or not the transmission capacity calculated in S203 is equal to or higher than the transmission rate calculated in S202 (S204). If the transmission capacity is equal to or higher than the transmission speed (YES in S204), the compression method is determined to be “lossless” (S205). On the other hand, if the transmission capacity is less than the transmission speed (NO in S204), the compression method is determined to be “lossy” (S206).

  As described above, according to the wireless photographing system 1 of the present embodiment, the communication conditions are determined according to the communication environment, so that even large-capacity video data can be stably wirelessly transmitted.

  When transmitting video data using a plurality of communication antennas, for example, the video data may be distributed to the plurality of antennas in line units (0.5 lines, 1 line, etc.).

  As described above, in the present embodiment, when the transmission capacity is equal to or higher than the necessary transmission speed, the lossless compression method in which data is not deteriorated is used. At least one of the communication conditions determined in S12 of FIG. 5 (number of antennas, bandwidth, modulation scheme) may be changed. Specifically, when the difference between the transmission capacity and the transmission speed is a predetermined value or more, the number of antennas to be used or the modulation method (including coding rate) may be changed to the safe side to narrow the transmission capacity. . Thereby, radio wave intensity or noise tolerance can be improved.

  In this case, since each condition determined by the communication condition determination unit 32 is a provisional condition, the communication control unit 17 further has a function of determining (redetermining) the communication condition. Specifically, the communication control unit 17 further includes a re-determination unit (not shown) that re-determines the communication condition according to the comparison result between the transmission capacity and the transmission rate.

  For example, the re-determination unit may determine the priority order of the conditions to be changed according to each communication situation when the number of antennas and the modulation scheme provisionally determined by the communication condition determination unit 32 are employed. For example, when the BER (S164 in FIG. 13) calculated in the antenna number determination process (FIG. 13) is higher than the BER (S194 in FIG. 17) calculated in the modulation scheme determination process (FIG. 17), 1 Determine the number of antennas to be used as the number of antennas actually used.

  When the number of antennas to be used is reduced in this way, the communication distance between the imaging device 10 and the recording device 20 can be extended. For example, when the recording device 20 is realized by a portable terminal as will be described later, even if the communication distance between the adapters 10 and 20 is somewhat increased due to the movement of the recording device 20, the recording device 20 is used. It is possible to prevent the video data restoration rate from decreasing.

  In this embodiment, the communication condition is determined at the start of wireless shooting. However, even during communication, the communication environment (congestion status, communication distance, noise level) is monitored at a predetermined timing. It is desirable to appropriately reset (bandwidth, number of antennas, type of modulation scheme, and coding rate) as appropriate.

  In the present embodiment, in the bandwidth determination process, the maximum bandwidth of the continuously usable bandwidth group is determined. However, all the bandwidths that can be used regardless of whether they are continuous or discontinuous. May be determined. Specifically, for example, as shown in FIG. 20, in the case where channel 4 and channel 7 are used in other wireless communication, 120 MHz for 6 channels can be determined as an available bandwidth. .

  In this case, the video data may be divided according to the number of usable bands, and the video data may be transmitted using all six channels. That is, in the case of FIG. 20, 3/6 video data is transmitted using channels 1 to 3, 2/6 video data is transmitted using channels 5 and 6, and 1 / 6 video data is transmitted. By doing so, the available bandwidth can be effectively utilized. The data division may be performed, for example, for each line.

<Modification 1>
The relationship between the imaging device 10 and the recording device 20 may be a one-to-multiple relationship.

  FIG. 21 is a diagram schematically illustrating a wireless imaging system 1A according to the first modification of the present embodiment. In the wireless imaging system 1 </ b> A, a captured image of one imaging apparatus 10 is transmitted to two recording apparatuses 20. Even in such a case, basically, the same processing as the wireless photographing processing in the wireless photographing system 1 described above is performed. Only differences from the wireless imaging system 1 will be described below.

  It is desirable that the communication control unit 17 (FIG. 2) of the imaging device 10 determines the communication condition for each recording device 20. That is, in this modification, a condition determination unit (not shown) corresponding to the communication condition determination unit 32 illustrated in FIG. 3 determines the communication condition for each recording device 20 according to the analysis result of the environment analysis unit 31. It is desirable. 2 transmits (transfers) the captured video data to the two recording devices 20 under the determined communication conditions.

  Note that since the bandwidth does not depend on the reception side (recording device 20), the same determination method may be used as in the case of one-to-one transmission side and reception side. Since the video data transmitted from the imaging device 10 to the two recording devices 20 is the same, all of the available bandwidth can be used.

  When video data is transmitted to a plurality of recording devices 20, the communication conditions that need to be determined for each recording device 20 are the number of antennas and the modulation method.

  When the distance level, that is, the radio wave intensity is different in each of the recording devices 20, the number of antennas that can be used is determined in accordance with the far distance level. For example, when the number of antennas determined for one recording device 20 is eight and the number of antennas determined for the other recording device 20 is four, it can be used for communication with both recording devices 20. The maximum number of antennas is determined to be 4.

  Similarly, when the recording device 20 has a different noise level, the type and coding rate of the modulation scheme to be used are determined according to the higher noise level. For example, the type and coding rate of the modulation scheme determined for one recording apparatus 20 are 256QAM and 3/4, respectively, and the type and coding rate of the modulation scheme determined for the other recording apparatus 20 are, respectively. Are 64QAM and 2/3, respectively, the type and coding rate of the modulation scheme used for communication with both recording apparatuses 20 are determined to be 64QAM and 2/3.

  If the bands to be used are the same, the noise level generated in the wireless communication environment is considered to be roughly the same for both recording apparatuses 20. Therefore, when transmitting the same video data to a plurality of recording devices 20, the imaging device 10 only determines the modulation method using the pilot data with one of the two recording devices 20. May be.

  Also in this modification, the user of each recording device 20 can input a recording instruction at his / her favorite timing. Therefore, it is possible to take a favorite photograph in each recording device 20 only by having one photographing device 10 in the family. Or the tourist (user) can take a favorite photograph in each recording device 20 by installing the photographing device 10 in a popular spot in a sightseeing spot in advance.

  Note that the number of recording devices 20 may be three or more.

<Modification 2>
The relationship between the imaging device 10 and the recording device 20 may be a multiple-to-one relationship.

  FIG. 22 is a diagram schematically showing a wireless imaging system 1B according to the second modification of the present embodiment. In the wireless imaging system 1B, the captured images of the two imaging devices 10 are transmitted to one recording device 20. Even in such a case, basically, the same processing as the wireless photographing processing in the wireless photographing system 1 described above is performed. Only differences from the wireless imaging system 1 will be described below.

  In the present modification, both or one of the two imaging devices 10 can be set as target devices in the recording device 20 (S20 in FIG. 5). Here, it is assumed that two imaging devices 10 are set as target devices. That is, the IDs of the two imaging devices 10 (10a, 10b) are temporarily stored in the internal memory 29.

  In this case, when high-resolution video data is wirelessly transmitted from the two imaging devices 10 in the recording device 20, there is a possibility that a delay or data loss occurs. Therefore, the main video and the sub video may be displayed on the recording device 20, and the video data transmitted from the imaging device 10 that captures the sub video may have a low resolution.

  Specifically, immediately after the wireless shooting mode is set, the touch panel 23 of the recording device 20 displays low resolution videos (sub-videos) shot by the two shooting apparatuses 10a and 10b on two screens. A screen example of the touch panel 23 at this time is shown in FIG. In FIG. 23A, the video data of the imaging devices 10a and 10b are displayed in two relatively small display areas AR1 and AR2, respectively. For example, one band is used for transmission / reception of low-resolution video data.

  Thereafter, it is assumed that the video of one of the imaging devices 10a is selected by the user. In this case, the recording device 20 requests high-resolution video data from the photographing device 10a. Upon receiving this request, the imaging device 10a increases the bandwidth to be used. In the present modification, it is desirable that usable bandwidths are allocated in advance to the imaging device 10a and the imaging device 10b. For example, channels 1 to 3 for high resolution data transmission and channels 4 for low resolution data transmission are allocated to the imaging device 10a, and channels 5 to 7 for low resolution data transmission are allocated to the imaging device 10b. Channel 8 is assigned for resolution data transmission. This enables wireless communication between one recording device 20 and the plurality of photographing devices 10a and 10b.

  When the recording device 20 receives high-resolution video data from the imaging device 10a, the high-resolution video (main video) is displayed on the touch panel 23 in a relatively large display area AR3 as shown in FIG. Is done. In addition, a recording button BT1 is displayed in the vicinity of the display area AR3.

  In this state, when the recording button BT1 is pressed (selected), the data of the main video displayed at the time of pressing is saved in the image storage unit 28. During the wireless shooting mode, the main video can be switched, for example, by switching the selection states of the sub video display areas AR1 and AR2.

  In order to shoot a desired video using a general camera, the user needs to move his / her camera and adjust its angle and orientation. Therefore, for example, in sports watching, the angle of the video that the spectator can shoot is limited. However, according to this modification, it is possible to shoot images at various angles with one recording device 20.

  As described above, particularly when storing the images of the plurality of imaging devices 10, additional information may be added to the index data in order to facilitate later search in the recording device 20. In this case, additional information may be set every time video data is saved. That is, additional information may be set in the video data storage process shown in S27 of FIG. The flow of the video data storing process in this case is shown in FIG.

  Referring to FIG. 24, when a recording instruction is input, the control unit 22 of the recording apparatus 20 reads information on the photographing apparatus 10 side from the internal memory 29 (S41). The information on the photographing apparatus 10 side is, for example, information for specifying a place where the photographing apparatus 10 is installed (hereinafter referred to as “location specifying information”), and includes at least one of a photographing place (installation place) and a category. The category may include major classifications such as sports and sightseeing spots, and minor classifications such as baseball / soccer and sky tree / Mt. Fuji.

  Such location specifying information is received from each imaging device 10 at the time of establishing a communication connection, and is temporarily stored in the internal memory 29. Further, it is assumed that location specifying information is registered in advance in each photographing apparatus 10 from, for example, a communication terminal (which may be the recording apparatus 20). In each photographing apparatus 10, the location specifying information is stored in a nonvolatile manner in a storage unit such as the memory 19. Note that the location specifying information of the image capturing device 10 that has captured the image data to be stored may be displayed on the touch panel 23 and a change by the user may be accepted.

  Alternatively, the location specifying information may not be registered in the imaging device 10 in advance. In that case, an input field for inputting a shooting location and a category may be displayed on the touch panel 23, and the user may input characters and symbols in each field via the operation unit 24. Such setting of the location specifying information by the user may be performed only when saving the video data for the first time (may be omitted in the second and subsequent saving processes).

  Next, the control unit 22 of the recording apparatus 20 accepts setting of user-specific information (S42). Specifically, a comment field for inputting a keyword is displayed on the touch panel 23, and the user inputs characters and symbols into each field via the operation unit 24. Alternatively, when the recording device 20 has a voice input unit (not shown), the keyword may be registered by voice.

  The control unit 22 of the recording device 20 adds the read information on the photographing device 10 side and the set user-specific information to the index data as additional information, and stores the video data (S43). An example of the data structure of the index data is shown in FIG. As shown in FIG. 25, each index data includes a shooting location, a category, and a keyword as additional information in addition to the ID of the shooting device 10a, the shooting date and time, and the video data address. Note that the shooting location may include the installation status (front / right side, etc.) of the shooting device 10.

  By storing such index data in association with each stored captured image, it is possible to easily select desired video data from a large number of recorded images.

  Note that the number of the imaging devices 10 may be three or more.

  In the embodiment and the first and second modifications described above, when the user selects the wireless shooting mode in the recording device 20, the connection is established by the image capturing device 10 and the recording device 20 transmitting and receiving identification information. It was decided to. Such a connection establishment method is effective when the photographing apparatus 10 and the recording apparatus 20 are registered in advance as target devices. However, when the photographing apparatus 10 is not owned by the user but owned by a company (for example, a sightseeing spot or a sponsor of a sports stadium), it is desirable to perform an authentication process separately. An example of the target device setting process (S20 in FIG. 5) in such a case is shown in FIG.

  Referring to FIG. 26, the control unit 22 of the recording device 20 searches for a communicable imaging device 10 (S31). Specifically, information (for example, position information) of the surrounding imaging device 10 is acquired and displayed on the touch panel 23. If it is assumed that the user is at a sports stadium, for example, it is possible to search for a communication apparatus 10 that can communicate with the web page of the stadium.

  Based on the information of each photographing device 10 displayed on the touch panel 23, the user selects one or a plurality of photographing devices 10 to be connected, and the target device setting process is executed (S32). Specifically, in the recording device 20, the target device is set by inputting an authentication ID or password notified to the user in advance.

  When such target device setting is performed, a plurality of imaging devices 10 and recording devices 20 may be provided. That is, a plurality of photographing devices 10 may be installed in an event place such as a stadium, and a visiting user may be able to acquire videos from the plurality of photographing devices 10 in each recording device 20.

  In this way, when the photographing apparatus 10 is a property of a company, location specifying information that can be included in the index data is registered in each photographing apparatus 10 from the server operated by the company via the Internet. May be.

  In the embodiment described above, the compression method of the video data can be changed according to the comparison result between the transmission capacity and the transmission speed. However, the compression method is predetermined as one of lossless compression and lossy compression. It may be done. That is, the communication control unit 17 may not include the compression method determination unit 34.

  Further, the communication condition determined by the communication condition determination unit 32 includes the number of antennas used for wireless communication, the bandwidth, the type of modulation scheme of the carrier wave, and the coding rate. At least one of these is included. As long as one is included. In this case, it is desirable that the communication conditions determined by the communication condition determination unit 32 include at least the bandwidth to be used.

  In the present embodiment, the example in which the number of communication antennas on the transmission side and the reception side is 8 has been shown, but the number is not limited, and may be 16 or 32, for example.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1, 1A, 1B wireless imaging system, 10, 10a, 10b imaging device, 11 lens unit, 12, 22 control unit, 13 wireless transmission unit, 14 compression unit, 15, 43 MIMO radio unit, 16a-16h, 44a-44h Communication antenna, 16m, 44m Measurement antenna, 17, 46 Communication control unit, 18, 23, 47 Storage unit, 19, 29 Memory, 20 Recording device, 21 Wireless reception unit, 23 Touch panel, 24 Operation unit, 25 Display unit, 26 timing unit, 27 drive device, 28 image storage unit, 31 environment analysis unit, 32 communication condition determination unit, 33 video analysis unit, 34 compression method determination unit, 35 notification processing unit, 45 decompression unit.

Claims (8)

A photographing device for photographing images;
A recording device that is physically separated from the imaging device and records the video captured by the imaging device;
The imaging device
A lens unit;
Wireless transmission means for streaming transmission of video data captured by the lens unit to the recording device;
The recording device comprises:
Wireless receiving means for wirelessly receiving video data transmitted from the wireless transmitting means;
Display means for displaying video data received by the wireless receiving means;
An operation means for receiving a recording instruction from a user in a state in which a video is displayed on the display means;
A wireless photographing system comprising: storage means for storing user-desired video data from video data received by the wireless reception means in accordance with the input timing of the recording instruction. The photographing apparatus analyzes a communication environment and determines a communication condition with the recording apparatus according to the analysis result, and a notification means that notifies the recording apparatus of the communication condition determined by the determination means Further including
The wireless imaging system according to claim 1, wherein the wireless reception unit of the recording apparatus receives video data transmitted from the wireless transmission unit based on a communication condition notified by the notification unit. The communication conditions include at least one of a bandwidth used for wireless communication, a type of carrier wave modulation method used for wireless communication, and a coding rate,
The wireless imaging system according to claim 2, wherein the wireless transmission unit wirelessly transmits video data to the recording apparatus using the orthogonal frequency division multiplexing method under the communication condition determined by the determination unit. The imaging device and the recording device each include a plurality of communication antennas,
The wireless transmission means transmits video data by a MIMO method,
The wireless photographing system according to claim 2, wherein the determination unit determines the number of antennas used for wireless communication among the plurality of communication antennas as one of the communication conditions. The recording device receives video data from a plurality of the photographing devices,
5. The wireless imaging system according to claim 1, wherein the storage unit of the recording apparatus stores the video data in association with index data including identification information of the imaging apparatus.   The wireless imaging system according to claim 5, wherein the index data further includes at least one of an installation location and a category of the imaging device.   The wireless imaging system according to claim 1, wherein the connection between the imaging apparatus and the recording apparatus is established by transmitting and receiving identification information. An imaging device capable of wireless communication with a recording device,
A lens unit for taking images,
Analyzing means for analyzing a communication environment, and determining a communication condition with the recording device according to the analysis result;
Notification means for notifying the recording apparatus of the communication conditions determined by the determination means;
An imaging apparatus comprising: a wireless transmission unit configured to stream-transmit video data captured by the lens unit to the recording device based on the communication condition determined by the determination unit.

Images