JP4683652B2 - Image data transmission / reception system, image data transmission device, control method therefor, and computer program - Google Patents

Description

  The present invention relates to a technique for transmitting and receiving image data between devices.

  Conventionally, there is a technique for exchanging image data between digital cameras.

  For example, Patent Document 1 discloses a technique in which a digital camera receives image data desired by a user from among image data stored in another digital camera without using a PC. This digital camera transmits thumbnail images to and from a digital camera with which communication has been established, and displays each received thumbnail image. This is because image data associated with the thumbnail image selected by the user from among the displayed thumbnail images is “browse”, “replicated”, and “moved” from the other digital camera. Here, “browsing” records image data in the built-in memory, “duplicate” records image data on an information recording medium, and “move” records image data on the information recording medium, and then transmits image data. The image data is deleted from the original.

  Patent Document 2 discloses a technique for exchanging images with a plurality of imaging devices. Specifically, one imaging device serves as a master and detects an imaging device serving as a slave. When one slave device is selected from a plurality of slave devices displayed on the screen of the master imaging device, thumbnail images stored in the slave device are transmitted to the master and displayed on the screen. When the user further selects a thumbnail image from the displayed images, a target image associated with the thumbnail image can be acquired.

In Patent Document 3, when an electronic still camera is connected to another electronic still camera, the electronic still camera whose shutter is pressed functions as a master, and the other cameras function as slaves. Then, in accordance with an instruction from the master, image transmission from the master to the slave, image transmission from the slave to the master, shooting instruction from the master to the slave, image erasure control, and monitoring of the captured image of the slave are performed.
JP 2003-92719 A JP 2003-234987 A Japanese Patent Laid-Open No. 9-284696

  There is a technique for exchanging image data between digital cameras as in the conventional example. However, easy-to-understand image data for users that combine the browsing function and the image data transmission / reception function to receive image data from the device of the communication partner while maintaining the shareability that devices that transmit and receive image data view the same image The exchange method has not been reached.

  In response to this request, in Patent Document 1 described above, the images browsed by the respective devices at the time of image data exchange are not the common images but the image data of the other party. There is no sharing. In Patent Document 2, a device on the image data receiving side acquires a desired image data after unilaterally acquiring a thumbnail image list from a partner device selected by the user. Processing to display image data is not performed. According to Patent Document 3, the user of the receiving device must confirm the transmission target image data on the transmission-side LCD.

  Accordingly, the present invention is intended to provide a technique that enables intuitive transmission and reception of images while maintaining the sharing property that devices that transmit and receive image data view the same image.

In order to solve this problem, for example, the image communication system of the present invention has the following configuration. That is,
An image data transmission / reception system,
The device sending the image
A reduced image corresponding to the first image stored in the storage unit is displayed on the display unit, and a reduced image corresponding to a second image different from the first image is displayed after the reduced image corresponding to the first image is displayed. A transmission side display means for displaying an image;
A reduced image corresponding to the first image is transmitted to the receiving device when displayed on the transmission side display means, and a corresponding reduced image corresponding to the second image is displayed when the reduced image corresponding to the second image is displayed. Reduced image transmission means for transmitting a reduced image to be transmitted to the receiving device ;
When transmission of a reduced image by the reduced image transmission unit is being executed, if the transmission of an image corresponding to the reduced image transmitted by the reduced image transmission unit is requested from the receiving device, the requested Image transmitting means for transmitting the image to the receiving device ,
The receiving device is
When a reduced image corresponding to the first image transmitted by the reduced image transmission unit is received, the reduced image corresponding to the received first image is displayed, and the reduced image corresponding to the first image is displayed. Receiving side display means for displaying a reduced image corresponding to the received second image when a reduced image corresponding to the second image transmitted by the reduced image transmitting means is received after the image is displayed ; ,
Detecting means for detecting a request by the operation unit of an image corresponding to the reduced image displayed on the receiving side display means;
Request means for requesting the transmission side device to transmit an image corresponding to the reduced image displayed on the reception side display means when a request for an image is detected by the detection means;
Receiving means for receiving the image requested by the requesting means.

According to the present invention, while maintaining the share property that the device for transmitting and receiving an image to view the same image, clarity transmission and reception of image intuitively performed. Further, according to another aspect of the present invention, the transmission side user may stop transmitting an image if the device on the transmitting side does not want to transmit while maintaining the sharing that the device that transmits and receives the image views the same image. Therefore, it is possible to save the trouble of selecting an image to be transmitted in advance.

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

  FIG. 1 is a block diagram showing a schematic configuration of one device constituting the image data transmission / reception system according to the present embodiment. Examples of the image data transmission / reception device include a PDA, a mobile phone, a digital camera, and the like. In this embodiment, a digital camera is taken as an example of the device.

  The digital camera 101 includes a control unit 102, a storage unit 103, a communication unit 104, a display unit 105, an input unit 106, and a photographing unit 107. The memory | storage part 103, the communication part 104, the display part 105, the input part 106, and the imaging | photography part 107 are connected to the control circuit which is the control part 102, and the control part 102 controls these collectively. The control unit 102 also executes digital image processing including compression processing of captured image data from the imaging unit 107, interpretation and execution of data and commands received by the communication unit 104, control for instructions from the input unit 106, and the like.

  The imaging unit 107 includes a lens for imaging, a CCD, and a digital image processing circuit. The CCD converts the optical image projected by the lens into an electrical signal, and the digital image processing circuit digitizes the image signal obtained from the CCD.

  The storage unit 103 includes a ROM that stores a control program executed by the control unit 102 and a RAM that is used as a work area. In addition, the storage unit 103 includes a flash memory that stores device-specific information such as a device ID, a device name, an icon image representing an overview of the device, an application program, and the like, which are device-specific identifiers. The storage unit 103 includes an I / F for accessing a removable memory card for storing image data captured by the imaging unit 107, image data received from another device, and the like. Examples of the memory card include a compact flash card (registered trademark) and an SD card.

  The communication unit 104 transmits and receives image data and control commands between external communication devices. In the case of wireless, an antenna and a wireless communication circuit are provided.

  The display unit 105 includes an LCD and an LCD control circuit that display a finder of a digital camera, a camera setting program, and a GUI (Graphical User Interface) of other application programs.

  The input unit 106 includes a shutter button of a digital camera, a key for instructing camera settings, a button on a GUI displayed on the LCD, a key for instructing GUI parts such as a text field, and a cross key. When various keys are operated by the user, the control unit 102 executes a program corresponding to the keys.

  FIG. 2 shows a state where the image data exchange devices according to the present embodiment are communicating with each other. FIG. 2A shows a one-to-one communication state between devices. FIG. 5B shows a communication state in which communication between devices is one-to-many. In the figure, a digital camera, a PDA, and a mobile phone are in a communication state by wireless connection. A wired connection may be used instead of a wireless connection. One device that transmits image data transmits image data to one device or a plurality of devices that are connected for communication. In the present embodiment, transmission / reception of one-to-one image data will be described.

  The communication means of the device for exchanging image data in this proposal may be either a wireless or wired communication method, but the device in this embodiment has a Bluetooth communication module and communicates with an external device by wireless communication. And

  Bluetooth is a wireless transmission method using a 2.4 GHz frequency band. The maximum communication distance is 10 m to 100 m (depending on the transmission output), and since it has low power consumption, it can be mounted on a small device.

  The device in this embodiment has an image data transmission / reception program in the ROM or flash memory that establishes communication with other devices and exchanges image data by processing such as transmission / reception of commands and image data. And it transfers to communication mode by running this program.

  In the present embodiment, image data stored in the storage unit 103 provided in the device (digital camera in the embodiment) is transmitted to another device. For this reason, it is not essential for the image data transmitting / receiving device to include an image capturing unit such as a digital camera. Therefore, the image data transmitting / receiving device may be a storage unit that records image data, a PDA having a communication unit that communicates with other devices, or a mobile phone. In the present embodiment, a device that transmits image data is referred to as a master device.

  In the following description, it is assumed that the image data transmitting / receiving device is a digital camera.

  Digital cameras store image data on removable media. The stored image data includes large-size image data depending on the imaging resolution of the imaging unit 107 and a small-size thumbnail image for confirmation of the image data.

  FIG. 3 is a device information table stored in the storage unit by the digital camera. FIGS. 2A and 2B are device information tables (stored in a ROM or a flash memory) that are stored in the storage unit in each of the digital cameras A and B appearing in the present embodiment. ing). The device information table is a device ID, a self-device camera name, and icon data for uniquely identifying the self-device. In this embodiment, the device ID is a Bluetooth device address assigned to each device that performs Bluetooth communication, the self-device camera name is the name of the digital camera, and the icon data is image data that represents an overview of the digital camera.

  FIG. 4 shows a display unit and an operation unit on the back of a digital camera which is an image data exchange device according to the present embodiment. The digital camera 401 includes a display screen (LCD) 407 and a shutter 402 that gives an imaging instruction. The digital camera 401 has a “menu” button 403 for switching various settings of the camera and a menu GUI for selecting an application to be activated. The digital camera 401 also has a cross key 406 for instructing an up / down / left / right direction for selecting an object in the menu GUI and switching a display image. The digital camera 401 also includes a “decision” button 404 for executing an object designated by the GUI, and a “cancel” button 405 for canceling the selection of an object on the GUI and stopping the execution of the program.

  In this embodiment, a digital camera that transmits image data is a digital camera A, and a digital camera on the image data receiving side is a digital camera B. First, a process until the digital camera A determines to transmit / receive image data to / from the digital camera B, a process of transmitting / receiving thumbnail image data, and a main image data transmission / reception process will be described.

<Image data exchange device decision processing>
First, the digital camera A executes an application for transmitting image data stored in the storage unit.

  To start this application, the user first presses the “menu” button 403. As a result, the control unit 102 displays an application menu (not shown) on the display unit 105. Next, when the control unit 102 detects that the user operates the cross key 406, moves the selection cursor to “image data communication” in the menu, and presses the “decision” button 404, the image data transmission / reception program Will be executed. By executing the image data communication program, a GUI for proceeding with the process of determining a device that transmits and receives image data is displayed on the LCD. FIG. 5 shows the GUI displayed on the LCD at this time.

  The GUI shown in FIG. 5 is provided with a device search button 502 for executing processing for searching for a communicable device. Further, in this GUI, a search result field 501 for displaying information of the searched device, and a device selection button 503 for selecting a device for transmitting / receiving image data from the devices displayed in the search result field. Is provided. The GUI is also provided with a message field 504 for displaying a message for notifying a processing result, a processing state, and the like. The buttons on the GUI are selected and determined by the cross key 406 and the determination button 404, and processing associated with the button on the GUI selected by the determination instruction is executed.

  A flowchart of FIG. 6 shows a schematic processing flow of the control unit 102 of the digital camera A (master) from when the device search button 502 is pressed until a digital camera for transmitting and receiving image data is determined.

  First, when the image device search button is pressed, the digital camera searches for an external device capable of communication (step S601). The control unit 102 controls the communication unit 104 to perform “inquiry” and “call” processing in the Bluetooth synchronization establishment phase, and searches for a device that exists within the communicable range of the digital camera A. If no device is detected (no acknowledgment is returned), a message “Device not detected.” Is displayed in the message column 504 to notify that no device is detected (step S608).

  On the other hand, if a device is detected, device information (see FIG. 3) is acquired from the device and displayed in the search result field 501 (step S603). Here, it is assumed that digital cameras B to E exist in the vicinity of the digital camera A, and these four digital cameras are detected. In this case, the search result field 501 of the digital camera A displays the search result shown in FIG. A square frame around “camera B” in the illustrated search result field 501 represents a pointing destination indicating the selected object. The position of the pointer can be changed to another object (button or other camera) on another GUI by operating the cross key 406.

A selection of a device to which image data is transmitted from the devices displayed in the search result field 501 by the user is detected (step S604). Selection is performed by using the cross key 406 to move the pointing destination from the four digital cameras to the other device to which image data is to be transmitted. Then, the device indicated by pointing when the determination button 404 is pressed is determined as a device to be transmitted. In this example, the enter button 404 is operated with “Camera B” selected as the illustrated communication device. FIG. 8 shows a display example in the search field 501 when “camera B” is confirmed. As shown in the figure, in order to notify that “Camera B” has been selected, the icon of “Camera B” is displayed with a thick frame for a predetermined time.

  When the transmission destination device is determined in this manner, the control unit 102 controls the communication unit 104 to transmit a “shared device notification” indicating that the digital camera B has been selected as an image data transmission / reception device ( Step S605).

  Upon receiving this shared device notification, the digital camera B makes a response as to whether or not to exchange image data with the digital camera A. For example, the GUI of the digital camera B displays that the shared device notification has been received from the digital camera A and a GUI for selecting whether or not the sharing device notification can be received, and allows the user of the digital camera B to select one of them. . This selection result is transmitted to the digital camera A as response information.

  Receiving the response to the shared device notification, the digital camera A determines whether the response agrees with the transmission / reception of the image data or rejects it (step S606). If the digital camera B refuses to become a device for exchanging image data, a message “No image data exchange partner” is displayed in the message column 504 to that effect (step S608). Conversely, if the digital camera B agrees, the digital camera A displays the device information of the agreed device on the LCD (step S607).

  FIG. 9 shows a display example of the digital camera A when the image data transmission / reception target device is determined as described above. As shown in the figure, the exchange target field 901 displays the name and icon of the digital camera B that is the target of transmission and reception. An exchange start button 902 for starting exchange of image data is also displayed as a GUI.

  Next, the communication procedure for the process of determining the image data transmission / reception partner will be described.

  Communication between devices is performed by packet communication. FIG. 10 shows the data structure of the communication packet. The illustrated communication packet is a Bluetooth payload portion. The packet includes a packet transmission source device ID, a transmission destination device ID command ID indicating the type of command, and parameter data for each command. However, some packets do not have parameter data. A unique device ID assigned to each device is used as the source device ID and destination device ID of the packet. The device ID may be a serial number assigned uniquely to the device when the device is manufactured. However, each device that performs Bluetooth communication is uniquely given an address called a Bluetooth device address. Therefore, in this embodiment, the Bluetooth device address is handled as a device ID. Of course, since the transmission source and the transmission destination need only be determined uniquely, for example, a MAC address may be used.

Device receiving a communication packet, stores information of the communication packet to the RAM, it performs processing corresponding to the command I D.

  Note that the command IDs and parameters of communication packets used in the proposed embodiment are collectively shown in FIG. FIG. 11 shows a communication procedure for determining an image data exchange partner.

  When the device search button 502 is pressed on the digital camera A, the control unit 102 of the digital camera A performs “inquiry” and “call” processing for establishing Bluetooth synchronization (timing 1101). The digital camera A can know the Bluetooth device address of the Bluetooth device in the vicinity of the digital camera A through the “inquiry” and “call” processing. In this example, the Bluetooth device addresses of the digital camera B, digital camera C, digital camera D, and digital camera E in the vicinity are stored in a search device table secured in the storage unit 103.

  FIG. 12 shows this search device table. The search device table is a table that records the Bluetooth device address and device information of the device searched in the “inquiry” and “call” processes.

  In the present embodiment, in order to specify the digital cameras B to E, a Bluetooth device address is handled as a device ID. In the present embodiment, the device IDs are denoted as device ID_B, device ID_C, device ID_D, and device ID_E, respectively.

  If no device is detected, a message “Device not detected.” Is displayed in the message column 504 to notify that the device is not detected.

  Next, device information (camera name, icon) is acquired from the detected device. In order to obtain the information, the digital camera A transmits a device information request communication packet to the detected device (timing 1102 to 1105). The device information request communication packet is a communication packet having “1” as a command ID (see FIG. 27). The device ID_A that is the Bluetooth device address stored as the device ID in the information table is stored in the source device ID of the communication packet. Also, any Bluetooth device address stored in the search device table is stored in the destination device ID of the communication packet. Then, “1” is stored in the command ID of the communication packet. The communication packet generated in this way is transmitted to the device indicated by the transmission destination device ID.

  When each of the digital cameras B to E receives the device information request communication packet with the command ID “1”, the digital camera A sends the device information response communication packet containing its own device information in the parameter portion to the device information request source digital camera A. Send. This is shown by timings 1106 to 1109.

  “2” is stored in the command ID of the device information response communication packet, and the parameter portion includes a device ID, a device name, a data length of icon data, and icon data read from the device information table of the storage unit. Stored. In this way, each device (digital cameras B to E) transmits the generated device information response communication packet to the digital camera A.

  The digital camera A receives a device information response communication packet transmitted from the device that requested the device information. If it is determined that the command ID of the received packet is “2”, the device information stored in the parameter portion of the device information response communication packet is read and stored in the device information table. For example, in the case of a device information response communication packet received from the digital camera B, the parameter ID includes device ID_B as the device ID and “camera B” as the device name. Furthermore, an icon image icon B indicating the icon data length and an overview of the digital camera B is also stored. Therefore, the digital camera A stores “camera B” in the column of the device name (1) for the device ID_B in the device information table and the icon B in the column of the icon (1). Similarly, the information in the parameters of the device information response communication packet received from the digital camera C, digital camera D, and digital camera E is also stored in the device information table.

  When the processing for all received device information response communication packets is completed, the information is displayed in the search result field 501 (FIG. 7).

  When the device information is displayed in the search result field 501, the user uses the cross key 406 and the determination button 404 to select and confirm a device as an image data exchange partner, and presses the device selection button 503 (timing 1116). .

  Then, to the device selected by pressing the device selection button 503, the digital camera A transmits a sharing notification communication packet notifying that the exchange of image data is desired (timing 1110). The sharing notification communication packet is a communication packet that stores the command ID “3” and the device information of the digital camera A that is the transmission source as a parameter. In the present embodiment, an example in which the digital camera A transmits and receives image data to and from the digital camera B is described. Therefore, the digital camera A reads the device name and icon data from the device information table, and generates a sharing notification communication packet stored in the parameter part in the order of the device name, icon data length, and icon data. Then, the digital camera A transmits the generated sharing notification communication packet with the device ID of the digital camera B as the transmission destination ID.

  When the digital camera B that has received the sharing notification communication packet determines that the command ID of the received communication packet is “3”, the digital camera B displays a sharing notification dialog asking whether to exchange image data on the LCD (timing 1112). . FIG. 13 shows a rear external view of the digital camera B and an LCD display example at this timing.

  In the sharing notification dialog 1301, information on a device for transmitting a sharing notification communication packet and a message “Do you want to exchange image data?” Prompting the user to input are displayed. Furthermore, a “Yes” button 1302 and a “No” button 1303 for the user to input whether or not to exchange image data are also displayed. Information on the device that has transmitted the sharing notification communication packet is obtained by reading out the device name and icon data stored in the parameter portion of the packet.

  The user of the digital camera B presses either the “Yes” button or the “No” button on the dialog with the cross key and the enter button (timing 1113). When the button is pressed, a shared response communication packet containing information on whether to transmit / receive image data is transmitted to the digital camera A that is the transmission source of the sharing notification communication packet. The shared response communication packet contains a command ID “4”, and the parameter portion contains information on whether or not to transmit / receive image data to / from the digital camera A. For example, “1” is stored when image data is transmitted and received, and “0” is stored when not. Therefore, when the user selects the “Yes” button 1302 on the sharing notification dialog, the shared response communication packet containing “1” and “0” in the parameter part is digital when the “No” button 1303 is selected. Sent to camera A. When either button is pressed, the dialog is hidden.

  Further, when the “Yes” button is pressed, the digital camera B executes the image data transmission / reception program stored in the storage unit, and the device information of the digital camera A that is the partner of image data transmission / reception is shown in FIG. Store in the shared device table.

  Receiving the shared response communication packet, when the digital camera A determines that the command ID of the received communication packet is “4”, the digital camera A reads information on the parameter portion including information on whether to transmit / receive image data. .

  When the read information is “1”, which means that image data is desired to be shared, the device information of the transmission source of the shared response communication packet is stored in the shared device table of the digital camera A that stores information on the other party to which image data is transmitted and received Fit. At this time, since the device information is not stored in the parameter portion, the device information is copied from the search device table from the transmission source device ID of the shared response communication packet. Then, the exchange target field 901 including the device information is displayed on the LCD (timing 1117).

On the other hand, when the read information is “0” which has the meaning of refusing to share image data, there is no device that transmits / receives image data to / from digital camera A. Therefore, in the case such as this is, "I do not have any image data exchange partner" message is displayed on the message field 504.

<Thumbnail image data transmission / reception processing>
Next, a procedure for transmitting thumbnail image data to the digital camera B determined as the image data transmission partner by the digital camera A will be described.

  Image data of the digital camera is stored in a storage unit of the digital camera, for example, a memory card inserted in a slot. The image data includes an image data ID, image data, and thumbnail image data which is image data reduced image data, as in the image data table shown in FIG.

  The flowchart in FIG. 16 shows the flow of thumbnail image data transmission processing executed by the control unit 102 of the digital camera A on the thumbnail image data transmission side. The digital camera A sequentially transmits the thumbnail image data stored in the storage unit to the digital camera B that is the image data transmission destination. In this example, the thumbnail image data to be transmitted is all thumbnail image data stored in the storage unit of the digital camera. However, as with the slide show function provided in many digital cameras, only thumbnail image data selected in advance by the user may be the transmission target.

Thumbnail image data transmission process begins more pressing the digital camera A data exchange button 902 displayed on the LCD of determined as image data reception device. A program relating to this processing is stored in the storage unit 103 and executed by the control unit 102.

  When the data exchange button 902 is pressed, the number N of thumbnail image data stored in the image data table is counted (step S16011). Next, a variable n for counting the number of image data that has been transmitted is initialized to “0” (step S1602).

  Next, the variable n and the variable N are compared (step S1603). If the variable n is smaller than the variable N, it means that transmission of all thumbnail image data to be transmitted has not been completed. In this case, the nth thumbnail image data in the image data table is read (step S1604). The read thumbnail image data is displayed on the LCD (step S1605) and transmitted to the digital camera B which is the image data transmission destination determined in the previous communication (step S1606).

  In order to display the transmitted thumbnail image data until the next thumbnail image data is read, an appropriate interval time T1 seconds is waited (step S1607). Thereafter, the variable n for counting image data is incremented by one (step S1608), and the process proceeds to the next thumbnail image transmission process.

  When the variable n is smaller than N, the next thumbnail image data is sequentially read and the thumbnail image data is transmitted to the digital camera B.

  When the variable n reaches the variable N, all the transmission target thumbnail image data has been transmitted, so the digital camera B is notified of the end of transmission of the thumbnail image data.

  The digital camera B on the thumbnail image data receiving side displays thumbnail image data on the LCD every time it is received.

  FIG. 17 shows a sequence of thumbnails displayed on the LCD on the back of each of the digital camera A that transmits thumbnail image data and the digital camera B that has received the thumbnail image data.

  The digital camera A displays the read thumbnail image data (A1) and transmits it to the digital camera B. Until the next thumbnail image data is displayed, the previous image data is displayed as it is. After the interval time T1 seconds, the next read thumbnail image data is displayed (A2).

  When receiving the thumbnail image data from the digital camera A, the digital camera B displays the received thumbnail image data on the LCD (B1). The display is continued until the next image data is received, and when the next thumbnail image data is received, the image data is displayed (B2).

  FIG. 18 shows a communication procedure of thumbnail image data transmission / reception processing.

  The digital camera A reads the first thumbnail image data (timing 1801) and displays it on its own LCD (1802). Then, the read thumbnail image data is transmitted to the digital camera B by the thumbnail image data transmission communication packet (timing 1807). The command ID of the thumbnail image data communication packet is “20”, and the parameter stores the image data ID read from the image data table, the thumbnail image data length, and the thumbnail image data.

  When the digital camera B receives the thumbnail image data transmission communication packet and determines that the command ID is “20”, the digital camera B reads the parameter portion information and stores it in the RAM. Then, the thumbnail image data stored in the RAM is read and displayed on the LCD (timing 1811). Thereafter, when a thumbnail image data transmission communication packet is received, the same processing is performed (timing 1812, 1813).

  After the transmission of the thumbnail image data, the digital camera A performs reading, display, and transmission processing of the next thumbnail image data after every interval time T1 seconds. When transmission of the last (N-1) th thumbnail image data is completed, a thumbnail image data transmission end communication packet is finally transmitted (timing 1810). “21” is stored in the command ID of the thumbnail image data transmission end communication packet.

  When the digital camera B receives the thumbnail image data transmission end communication packet and determines that the command ID is “21”, the digital camera B ends the display of the last received image data.

  Here, the thumbnail image data received from the digital camera A is stored in the RAM of the digital camera B, but may be stored in a flash memory or a memory card. By storing in the flash memory, the thumbnail image data can be reproduced by the digital camera B even after the power is turned off / on.

<Image data transmission / reception processing>
Finally, a process for acquiring large-size image data (hereinafter referred to as main image data) for thumbnail image data will be described.

  The user of the digital camera B can browse the thumbnail image data from the digital camera A that is sequentially displayed on the LCD. When the user wants the actual image data of the thumbnail image data displayed on the LCD, the user presses the decision button within a predetermined time when the thumbnail image data is displayed on the LCD. Desired main image data is received.

  FIG. 19 shows the flow of processing when the decision button is pressed while the thumbnail image data received on the LCD is being displayed by the digital camera B.

  When the determination button is pressed while the thumbnail image data is displayed on the LCD, the digital camera B (the control unit thereof) creates a thread different from the main thread for receiving the thumbnail image data (step S1901). . A thread is a unit for executing a program, and parallel processing can be performed by creating another thread for a primary thread that is a main thread. In this example, transmission / reception of thumbnail image data is performed by the primary thread, and transmission / reception of the main image data is performed between the digital camera A and the digital camera B by another thread. By performing such parallel processing, it is possible to continue browsing thumbnail images sequentially while transmitting and receiving main image data.

  The image data ID for the thumbnail image data being displayed on the LCD in another thread is read from the RAM (step S1902). Then, a main image data request communication packet is transmitted to the digital camera A in order to request main image data for thumbnail image data (step S1903). The command ID of this image data request communication packet is “22” (see FIG. 27), and the read image data ID is stored and transmitted in the parameter portion. The system waits for the requested main image data to be transmitted from the digital camera A by the main image data request communication packet (step S1904).

  When the main image data request communication packet is received during standby, it is confirmed that the command ID is “23”. Thereafter, the image data stored in the parameter portion of the main image data request communication packet is read and stored in a memory card connected to the digital camera B (step S1905). Saving saves the thread.

  On the other hand, FIG. 20 shows a processing flow of the digital camera A that has requested the main image data.

  When the digital camera A receives the main image data request communication packet and determines that the command ID is “22”, the digital camera A creates another thread for transmitting the main image data (step S2001). In another thread, the image data ID of the main image data requested by the digital camera B is read from the parameter portion of the main request image data request communication packet, and the main image data matching the image data ID is read from the image data table (step S2002). ). Then, the main image data is transmitted with the digital camera B as the transmission destination (step S2003). The main image data is transmitted by a main image data transmission communication packet in which the command ID “23”, the image data ID, the main image data length, and the main image data are stored in the parameter portion. The thread that transmits the main image data ends when the transmission of the main image data ends.

  With the above processing, the digital camera B can receive the main image data for the currently displayed thumbnail image data from the digital camera A by pressing the enter button while displaying the thumbnail image data on the LCD. .

  In the present embodiment, an example has been described in which devices transmit and receive image data on a one-to-one basis. However, it is also possible for one transmitting device to transmit image data to a plurality of devices.

  In this case, in the <image data exchange device determination process> described above, the digital camera A does not select only the digital camera B as the other party to which the image data is transmitted. Select a digital camera. In <thumbnail image data transmission / reception processing>, thumbnail image data is not transmitted only to the digitized camera B, but one thumbnail image data is transmitted to the digital cameras B to D. Then, after that, the next thumbnail image data may be read out and similarly transmitted to each digital camera. Also, in <image data transmission processing>, the users of the digital cameras B to D on the thumbnail image data receiving side press the determination button of each camera to designate desired image data. Thereby, each digital camera can acquire desired main image data from the digital camera A by parallel processing using different threads.

<Second Embodiment>
In the above embodiment (first embodiment), it is assumed that the main image data itself is transmitted between the digital cameras. Therefore, when the transmission is hacked, the main image data is received by an unpredicted device, and is easy. There is a risk that this image data will be disseminated. Therefore, an example in which an encryption step is provided in a processing flow for transmission / reception between devices will be described as a second embodiment.

  In the present embodiment, cryptographic processing using a public key cryptosystem is performed. The public key encryption method is an encryption method that performs encryption / decryption of data using two keys that are a pair of a public key and a secret key. RSA is a typical public key cryptosystem. In the second embodiment, for example, RSA is used. Of course, other encryption methods may be used.

  The <image data exchange device determination process> in the second embodiment is almost the same as in the first embodiment, but at the end of this process, the public key of the digital camera B that is the receiving device is received. The image data is transmitted to the digital camera A on the transmission side.

  The digital camera B holds a public key for encryption in a storage unit, for example, a memory card. This public key is created with a tool that generates a pair of a general public key and a private key. In particular, it is not necessary to create a public key in the digital camera. The public key created in the PC may be stored in a memory card so that the digital camera can handle the public key via the memory card.

  In the second embodiment, at the end of the image data exchange device determination process of the first embodiment, the digital camera B on the image data receiving side transmits a shared response communication packet to the digital camera A. The shared response communication packet stores information on whether or not to exchange image data in a parameter portion. In the second embodiment, the following processing is performed when the user presses the “Yes” button in the sharing notification dialog shown in FIG. First, the digital camera B (the control unit thereof) has, in the parameter portion, a shared response communication packet storing information “1” indicating that image data exchange is desired and public key information for encrypting the image data. Create Then, the digital camera B transmits the created packet to the digital camera A as a shared response communication packet.

  When the digital camera A that receives the shared response communication packet determines that the command ID is “4”, it reads information from the parameter portion. Then, when “1” for exchanging image data is included, the stored public key is stored in the shared device table of the storage unit. FIG. 21 shows a shared device table of the digital camera A. The shared device table stores a Bluetooth device address, a device name, an icon, and a public key, which are device information of the digital camera B that exchanges image data.

  The next processing in the image data exchange, that is, <thumbnail image data transmission / reception processing> is the same as that in the first embodiment, and thus description thereof is omitted.

  Next, <image data transmission processing> in the second embodiment will be described.

  In the following description, the thumbnail image data from the digital camera A is sequentially displayed on the LCD of the digital camera B as described in <Thumbnail image data transmission / reception processing>. Then, if the user of the digital camera B who is browsing it wishes to acquire the main image data of the thumbnail image data displayed on the LCD, the time during which the desired thumbnail image data is displayed on the LCD Just press the enter button. The processing performed by the digital camera B when the button is pressed is the same as in the first embodiment. That is, according to the processing flow of FIG. 19, the image data is requested to the digital camera A, and the main image data transmitted from the digital camera A in response to the request is stored in the storage unit. The only difference is that the main image data is encrypted with a public key. The encrypted main image data is decrypted with a secret key stored in the PC, and the image data can be displayed and printed. Alternatively, the digital camera B side may have secret key information and perform decryption of the received main image.

   On the other hand, the processing of the digital camera A that has received the main image data request communication packet is substantially the same as in the first embodiment, but a processing step for encrypting the main image data is added. FIG. 22 shows a processing flow of the digital camera A when the main image data request communication packet is received.

  When the control unit 102 of the digital camera A receives the main image data request communication packet and determines that the command ID is “22”, it creates another thread for transmitting the main image data (step S2201). In another thread, the image data ID of the main image data requested by the digital camera B is read from the parameter portion of the main request image data request communication packet, and the main image data matching the image data ID is read from the image data table (step S2202). ). The read main image data is not transmitted as it is, but is first encrypted with the public key obtained from the transmission destination device (step S2203). For this reason, the public key for the digital camera B is read from the shared device table, and the read image data is encrypted using the public key.

  Next, the encrypted main image data is transmitted to the digital camera B (step S2204). The encrypted main image data is transmitted by a main image data transmission communication packet in which the command ID “23”, the image data ID, the main image data length, and the main image data are stored in the parameter portion. Finally, the thread that transmits the main image data ends when the transmission of the main image data ends.

<Third Embodiment>
In the first embodiment, the timing at which the digital camera A sequentially transmits thumbnail image data is a certain interval time T1 seconds managed by the digital camera A.

  In the third embodiment, an example in which the digital camera A transmits thumbnail image data based on the timing of receiving the main image data request communication packet from the digital camera B on the image data receiving side will be described. The procedure is described below.

  FIG. 23 is a flowchart showing a flow of processing in which the control unit of the digital camera A transmits thumbnail image data.

  The procedure (steps S2301 to S2306) from when the digital camera A reads the thumbnail image data from the image data table and transmits the thumbnail image data communication packet is the same as the <thumbnail image data transmission / reception process> of the first embodiment. . Therefore, the description is omitted.

  When the first thumbnail image data is transmitted to the digital camera B, the digital camera A starts a timer for timeout processing and waits for reception of the main image data request communication packet from the digital camera B (step S2307). If the set timer has passed the predetermined time, the process proceeds to processing for displaying the next thumbnail image data (step S2308).

  When the main image data request communication packet is received, the digital camera A reads information stored in the parameter portion of the communication packet, and determines whether or not the parameter portion includes information (step S2310). In the parameter portion of the image data request communication packet handled in the third embodiment, when requesting image data, the desired image data ID is stored, and when no image data is requested, no information is stored in the parameter portion. And

  When the image data ID is stored in the parameter portion of the image data request communication packet, the main image data corresponding to the image data ID is stored in the digital camera B as in <image data transmission processing> of the first embodiment. Transmit (step S2311).

  When the image data ID is not stored in the parameter portion of the image data request communication packet, it indicates that the digital camera B is not requesting the main image data, and therefore the main image data is not transmitted.

  At this time, in order to easily express to the user of the digital camera A whether or not the digital camera B desires the main image data, the digital camera A receives the image data request communication packet and based on the result of reading the parameters. Play icons and audio data. For example, when the digital camera B desires image data, a palm-shaped icon or “Yes!” Etc. that shows that the image data is desired in the message field of the digital camera A as shown in FIG. Displays the text of Also, the audio data recorded with the voice “Yes!” Is reproduced. If the digital camera B does not want the image data, the digital camera A displays a sound such as an icon with a goo's hand or a text “I don't need”, or a voice data recording “I do n’t need”. Do.

  Thereafter, it is confirmed whether image data request communication packets have been received from all the image data exchange devices (step S2312). In this example, since only the digital camera B is exchanging image data with the digital camera A, when it is confirmed that the image data request communication packet has been received from the digital camera B, the next thumbnail image data display processing is performed. (Step S2308). That is, when the user of the digital camera B inputs an instruction indicating that the displayed thumbnail is unnecessary, the next thumbnail can be transmitted without the time T1 shown in the first embodiment.

  When the digital camera A is transmitting / receiving image data to / from a plurality of digital cameras other than the digital camera B, it is confirmed whether image data request communication packets from all the digital cameras have been received. When image data request communication packets are received from all digital cameras or when the time is up, the process proceeds to the next thumbnail image data display process.

  The digital camera A sequentially transmits all thumbnail image data according to the processing procedure of this flowchart.

  Next, a processing flow of the digital camera B that receives thumbnail image data will be described.

  In the first embodiment, the digital camera B displays the received thumbnail image data on the LCD, and transmits a university data request communication packet for requesting the main image data when the user presses the enter button during the display. I was supposed to. On the other hand, in the third embodiment, if the user wants to acquire the main image data related to the displayed thumbnail, the user presses the decision button, and if not, requests the display of the next thumbnail image data. The right side of the cross key is pressed. The processing of the digital camera B when the determination button is pressed executes the flowchart of FIG. 20 as in the first embodiment. When the right side of the cross key is pressed, a thread is not created, but a request communication packet for the next thumbnail is simply transmitted.

  In either case, the main image data request communication packet is transmitted to the digital camera A, but the information stored in the parameter portion is different.

  When the main image data is requested, the image data ID of the desired main image data is stored in the parameter portion. When the main image data is not requested, the parameter is transmitted without storing any information.

  As described above, according to the third embodiment, the timing at which the thumbnail image data is transmitted from the digital camera A is determined by the determination button or the cross key on all image data transmission target devices except for the case of timeout. This is the timing when the right of is pressed. Accordingly, the next thumbnail image data can be displayed at a timing desired by the user on the image data receiving side.

<Fourth Embodiment>
In the fourth embodiment, an example in which <thumbnail image data transmission / reception processing> in the first embodiment is changed will be described.

  In the first embodiment, all thumbnail image data stored in the image data table of the digital camera A is transmitted to the digital camera B. In the fourth embodiment, when a predetermined user input is detected while the read thumbnail image data is displayed on the image data transmission side device, a process of transmitting the displayed image data to the external device Processing means for reading the next image data without performing the above is provided. Further, the thumbnail image data is displayed for a predetermined time before the thumbnail image data is transmitted.

  In <thumbnail image data transmission / reception processing>, the processing on the thumbnail image data receiving side is the same as that in the first embodiment, and thus will not be described here. Similarly, processing for transmitting a thumbnail image data transmission end communication packet to the receiving device after transmitting the last thumbnail image data is the same as in the first embodiment, and thus will not be described here.

  FIG. 25 shows a flowchart including processing when the digital camera A stops transmission of thumbnail image data to the digital camera B.

  Similar to the first embodiment, the read thumbnail image data is displayed on the LCD (steps S2501 to S2505). In the fourth embodiment, before transmitting the read thumbnail image data, a predetermined time T2 seconds for continuing the display of the thumbnail image data is provided (step S2506).

  If it is detected that the user has pressed the cancel button within the predetermined time T2 seconds when the thumbnail image data is displayed (step S2507), the process proceeds to step S2510. That is, the digital camera A does not perform the transmission process of the displayed thumbnail image data and the waiting process for the T1 time (steps S2508 and S2509).

  If the pressing of the cancel button is not detected within T2 seconds, the thumbnail image data is transmitted to the digital camera B (step S2508). Then, after waiting for an interval time T1 seconds (step S2509), the process proceeds to the next thumbnail image data reading process (step S2510).

  An example of the communication sequence of the thumbnail image data transmission / reception process including the above thumbnail image data transmission stop process is shown in FIG.

  The control unit 102 of the digital camera A reads thumbnail image data from the image data table (timing 2601) and displays it on the LCD (timing 2602). The thumbnail image data display lasts for an interval time T2 seconds provided until transmission to the digital camera B (step S2616). Then, after T2 seconds, the currently displayed thumbnail image data is transmitted to the digital camera B (timing 2609). After that, as in the first embodiment, after the interval time T1 seconds until the next image data transmission (timing 2617), the process proceeds to the next image data reading process (timing 2604).

  On the other hand, the interval time T2 seconds is a time for continuously displaying the image data, and is a time for receiving an input for instructing the user to cancel the transmission of the image data. When it is detected that the “cancel” button is pressed within T2 seconds (timing 2618), at the detection stage, image data is not transmitted to the digital camera B, which is the next process, and the next process is performed. The process proceeds to image data reading processing (timing 2605). Then, the read thumbnail image data is displayed on the LCD (timing 2606).

  When an instruction to cancel transmission rejection is given in T2 seconds, the next image data that has been read out is displayed before T2 seconds elapse, so the time for displaying the thumbnail image data for which rejection has been canceled is as indicated by timing 2618. The time T2-α (seconds) is shorter than T2.

  By displaying thumbnail image data on the LCD of the transmitting device before transmission, the user can visually confirm the image to be transmitted, and by providing transmission rejection cancellation means, transmission of the visually observed image data can be performed. Can be canceled.

  Each embodiment according to the present invention has been described above, but in the embodiment, Bluetooth is used as an example of the wireless communication unit, but the present invention is not limited thereto. However, since it is desirable that the users of each device be close to each other so that they can be visually confirmed, communication means capable of high-speed transfer at a short distance, such as Bluetooth, is desirable.

  According to the above description, when a plurality of pieces of image data are transmitted from the device one by one, the user does not have to select and transmit image data one by one, so that the number of times of user input can be reduced.

  The transmitted image data is displayed at the same time on the image data transmitting device and the image data receiving device, and the user of each device can view the same image data at the same timing. You can have time to request viewing images.

  Furthermore, if the user performs a single input at the timing when the desired image is displayed while browsing sequentially transmitted image data, the image data can be acquired. Convenience for the user is improved with respect to acquisition.

  Further, the image data to be transmitted is displayed in advance before transmission by the device that transmits the image data. If it is not desired to transmit the displayed image data, the transmission of the image data can be stopped at that time by the user input, thereby saving the user from selecting the image data to be transmitted in advance. it can.

  In the embodiment, the example in which both the image transmitting device and the receiving device are digital cameras has been described. However, as long as it is a portable device having a display unit, the type is not limited to this, and a PDA, a mobile phone, a notebook PC, and the like are not limited. In particular, in the case of a PDA, a notebook PC, or the like, although hardware such as wireless communication means is required, it is realized by an application that cooperates with the hardware. Therefore, it is clear that the present invention is in the category of computer programs. In general, the computer program is stored in a computer-readable storage medium such as a CD-ROM. In order to execute the program, it is set in a reader (CD-ROM drive) or the like provided in the computer and copied or installed in the system. Accordingly, such a computer-readable storage medium is naturally within the scope of the present invention.

It is a block block diagram of the digital camera which concerns on embodiment. It is a figure which shows the example of the communication between devices which comprise the image data transmission / reception system which concerns on embodiment. It is a figure which shows the device information table which each digital camera stores in a memory | storage part. It is a figure which shows the display part of the digital camera which is a device in embodiment, and an operation part. It is a figure which shows the example of GUI for advancing the process which determines the device which exchanges image data. It is a flowchart which shows the device search processing procedure in a transmission side device. It is a figure which shows the example of GUI of a display of a device search result. It is a figure which shows the example of GUI of selection of a receiving object device. It is a figure which shows the example of a display of the camera name and icon of the determined image data exchange object device. It is a figure which shows the data structure of the communication packet transmitted between devices in an image data transmission / reception system. It is a figure which shows the communication sequence which determines an image data exchange device in an image data transmission / reception system. It is a figure which shows the example of a search device table. It is a figure which shows the example of GUI displayed when the digital camera of the side which receives image data receives a share notification from a transmission source. It is a figure which shows a shared device table. It is a figure which shows the image data table which stores image data. It is a flowchart which shows a transmission process of the thumbnail image data of the transmission device of image data. It is a figure which shows transition of the display of the thumbnail image data of a transmission side and a reception side. It is a figure which shows the example of the communication sequence which transmits / receives thumbnail image data between devices. It is a flowchart which shows the reception process of this image data in a receiving device. It is a flowchart which shows the transmission process of this image data in a transmission side device. It is a figure which shows the shared device table in 2nd Embodiment. It is a flowchart which shows the main image data transmission process of the transmission side device in 2nd Embodiment. 10 is a flowchart illustrating a transmission process of thumbnail image data of a transmission side device according to a third embodiment. It is a figure which shows the example of GUI when the transmission side device in 3rd Embodiment receives the image data request | requirement from the reception side device. 15 is a flowchart illustrating thumbnail image transmission processing in a transmission-side device according to the fourth embodiment. It is a figure which shows the example of the communication sequence which transmits / receives the thumbnail image data between the devices in 4th Embodiment. It is a figure which shows command ID and parameter of the communication packet used in this embodiment.

Claims (10)

An image data transmission / reception system,
The device sending the image
A reduced image corresponding to the first image stored in the storage unit is displayed on the display unit, and a reduced image corresponding to a second image different from the first image is displayed after the reduced image corresponding to the first image is displayed. A transmission side display means for displaying an image;
A reduced image corresponding to the first image is transmitted to the receiving device when displayed on the transmission side display means, and a corresponding reduced image corresponding to the second image is displayed when the reduced image corresponding to the second image is displayed. Reduced image transmission means for transmitting a reduced image to be transmitted to the receiving device ;
When transmission of a reduced image by the reduced image transmission unit is being executed, if the transmission of an image corresponding to the reduced image transmitted by the reduced image transmission unit is requested from the receiving device, the requested Image transmitting means for transmitting the image to the receiving device ,
The receiving device is
When a reduced image corresponding to the first image transmitted by the reduced image transmission unit is received, the reduced image corresponding to the received first image is displayed, and the reduced image corresponding to the first image is displayed. Receiving side display means for displaying a reduced image corresponding to the received second image when a reduced image corresponding to the second image transmitted by the reduced image transmitting means is received after the image is displayed ; ,
Detecting means for detecting a request by the operation unit of an image corresponding to the reduced image displayed on the receiving side display means;
Request means for requesting the transmission side device to transmit an image corresponding to the reduced image displayed on the reception side display means when a request for an image is detected by the detection means;
An image data transmitting / receiving system comprising: a receiving unit that receives an image requested by the requesting unit. An image data transmission device for transmitting image data ,
A reduced image corresponding to the first image stored in the storage unit is displayed on the display unit, and a reduced image corresponding to a second image different from the first image is displayed after the reduced image corresponding to the first image is displayed. A transmission side display means for displaying an image;
When displaying the reduced image corresponding to the first image on the transmission side display means, the reduced image corresponding to the first image is transmitted to the receiving side device, and the reduced image corresponding to the second image is transmitted. Reduced image transmission means for transmitting a reduced image corresponding to the second image to the receiving device when displaying ;
When transmission of a reduced image by the reduced image transmission unit is being executed, if the transmission of an image corresponding to the reduced image transmitted by the reduced image transmission unit is requested from the receiving device, the requested An image data transmitting device , comprising: an image transmitting unit configured to transmit the image to the receiving device. Search means for searching for a receiving device based on an instruction from the operation unit;
Further comprising a receiving device Display means for displaying on the display unit in order to select the receiving-side device which is searched by said searching means,
The reduced image transmit means, the image data transmission device according to claim 2, characterized in that the sending to the receiving side device selected by the operation by the operation unit. The transmission side display means displays a reduced image corresponding to the first image for a preset time, and after the display of the reduced image corresponding to the first image ends, the reduced image corresponding to the second image Display an image,
The reduced image transmission unit corresponds to the second image when the transmission side display unit displays the reduced image corresponding to the second image after transmitting the reduced image corresponding to the first image. 4. The image data transmitting device according to claim 2, wherein a reduced image to be transmitted is transmitted. When a request for the first image is received from the receiving device while the reduced image corresponding to the first image is being displayed by the transmitting side display unit, the transmitting side display unit Finish displaying the reduced image corresponding to the first image and display the reduced image corresponding to the second image;
4. The reduced image transmission unit transmits a reduced image corresponding to the second image to a receiving device when displaying the reduced image corresponding to the second image. The image data transmitting device described in 1 . Further comprising an encryption means for encrypting the image data;
The image transmit means, the image data transmission device according to any one of claims 2 to 5, characterized in that transmitting the encrypted image by said encrypting means to said receiving device. 3. The information processing apparatus according to claim 2, further comprising information indicating that transmission of an image displayed by the transmission-side display unit is requested from the reception-side device or information indicating that transmission is not performed. The image data transmitting device described. An image data transmission device for transmitting image data,
A reduced image corresponding to the first image stored in the storage unit is displayed on the display unit, and after the reduced image corresponding to the first image is displayed, a second image different from the first image is supported. Transmitting side display means for displaying a reduced image to be transmitted,
Reduced image transmission means for transmitting the reduced image to the receiving device after a predetermined time has elapsed since the reduced image was displayed on the transmission side display means;
An image transmitting unit that transmits the image to the receiving device when the receiving device requests transmission of an image corresponding to the reduced image transmitted by the reduced image transmitting unit;
A determination unit that determines whether or not an instruction to stop transmission of the reduced image is input from the operation unit before the predetermined time has elapsed since the transmission side display unit displayed the reduced image;
The reduced image transmission unit, when receiving the instruction input, stops transmitting the reduced image being displayed by the transmission side display unit to the reception side device,
The transmission side display means after the reduced image transmission means transmits the reduced image corresponding to the first image, or after the determination means determines that the transmission of the reduced image corresponding to the first image is stopped. An image data transmitting device that displays a reduced image corresponding to the second image . A method for controlling an image data transmission device, comprising:
The transmission side display means displays a reduced image corresponding to the first image stored in the storage unit on the display unit, and a second different from the first image after displaying the reduced image corresponding to the first image. A transmission side display process for displaying a reduced image corresponding to the image of
The reduced image transmission means transmits the reduced image corresponding to the first image to the receiving device when displaying the reduced image corresponding to the first image in the transmission side display step, and the second image A reduced image transmission step of transmitting a reduced image corresponding to the second image to the receiving device when displaying a reduced image corresponding to
When image transmission means requests transmission of an image corresponding to the reduced image transmitted in the reduced image transmission step from the receiving device while executing the reduced image transmission process in the reduced image transmission step And an image transmission step of transmitting the requested image to the receiving device . A processor in an image data transmitting device;
A reduced image corresponding to the first image stored in the storage unit is displayed on the display unit, and a reduced image corresponding to a second image different from the first image is displayed after the reduced image corresponding to the first image is displayed. A transmission side display means for displaying an image;
When displaying the reduced image corresponding to the first image on the transmission side display means, the reduced image corresponding to the first image is transmitted to the receiving side device, and the reduced image corresponding to the second image is transmitted. Reduced image transmission means for transmitting a reduced image corresponding to the second image to the receiving device when displaying;
When transmission of a reduced image by the reduced image transmission unit is being executed, if the transmission of an image corresponding to the reduced image transmitted by the reduced image transmission unit is requested from the receiving device, the requested A computer program for causing an image transmission unit to transmit the image to the receiving device .

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