Patent Publication Number: US-2016227052-A1

Title: Image data transmission device, image data reception device, and image data transmission and reception method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to and incorporates by reference the entire contents of Japanese Patent Application No. 2015-020496 filed in Japan on Feb. 4, 2015 and Japanese Patent Application No. 2015-096827 filed in Japan on May 11, 2015. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image data transmission device, an image data reception device, and an image data transmission and reception method. 
     2. Description of the Related Art 
     Conventionally, moving image data has been distributed via a communication network such as the Internet. In recent years, various devices such as a personal computer (PC), an image forming apparatus, and a mobile terminal have an image pickup function and a communication function. Electronic conferences (video conferences) and the like have been held by mutually transmitting and receiving moving image data picked up by these devices. 
     The reception side device that receives the distributed moving image data can view the moving image data. However, there may be a situation when one scene (image) in the moving image data is to be acquired as a still image. For example, still image data needs to be acquired when one scene in the moving image data is to be printed, or to be stored as a still image. In such a case, in the conventional technology, still image data is cut out from the distributed moving image data in the reception side device, and printing, saving, and the like are performed by using the still image data. 
     However, from the viewpoint of reducing traffic capacity and preventing delay, the moving image data to be distributed is generally moving image data having a small data quantity, obtained by reducing the resolution and the like of the moving image data picked up by the image pickup device. Thus, when still image data is acquired using the conventional method described above, there is a possibility that the image quality thereof becomes lower than the original image quality picked up by the image pickup device. 
     Therefore, there is a need for an image data transmission device, an image data reception device, and an image data transmission and reception method capable of acquiring still image data having a higher image quality, from the moving image data being distributed. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least partially solve the problems in the conventional technology. 
     According to an embodiment, an image data transmission device includes a first generation unit, a distribution unit, a first reception unit, a second generation unit, and a first transmission unit. The first generation unit generates, from first moving image data, second moving image data to be distributed. The distribution unit distributes the second moving image data generated by the first generation unit to an external device. The first reception unit receives an acquisition request for still image data from the external device, with respect to the second moving image data being distributed by the distribution unit. The second generation unit generates still image data from the first moving image data according to the acquisition request. The first transmission unit transmits the still image data generated by the second generation unit to the external device as a response to the acquisition request. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a configuration example of an image data transmission and reception system according to a first embodiment; 
         FIG. 2  is a diagram illustrating an example of an external configuration of an image forming apparatus; 
         FIG. 3  is a diagram illustrating another example of the external configuration of the image forming apparatus; 
         FIG. 4  is a diagram illustrating still another example of the external configuration of the image forming apparatus; 
         FIG. 5  is a block diagram illustrating an example of a hardware configuration of the image forming apparatus according to the first embodiment; 
         FIG. 6  is a block diagram illustrating an example of a functional configuration of the image forming apparatus according to the first embodiment; 
         FIG. 7  is a diagram illustrating an example of an initial screen; 
         FIG. 8  is a diagram illustrating an example of a camera image screen; 
         FIG. 9  is a diagram illustrating an example of a relation between a camera and a document platen; 
         FIG. 10  is a diagram illustrating an example of a guide image; 
         FIG. 11  is a diagram illustrating another example of the guide image; 
         FIG. 12  is a diagram illustrating an example of a focus position specification screen; 
         FIG. 13  is a diagram illustrating an example of a copy screen; 
         FIG. 14  is a schematic diagram illustrating an example of a data configuration of a focus position setting table; 
         FIG. 15  is a flowchart illustrating an example of a procedure of an operation receiving process; 
         FIG. 16  is a flowchart illustrating an example of a procedure of a focus position setting process; 
         FIG. 17  is a flowchart illustrating an example of a procedure of a document size changing process; 
         FIG. 18  is a diagram illustrating an example of a conference screen; 
         FIG. 19  is a diagram illustrating an example of a print mode screen; 
         FIG. 20  is a diagram illustrating an example of an accumulation mode screen; 
         FIG. 21  is a diagram illustrating an example of an image quality setting mode screen; 
         FIG. 22  is a schematic diagram illustrating an example of data transfer according to the exchange of still image data; 
         FIG. 23  is a schematic diagram illustrating another example of the data transfer according to the exchange of still image data; 
         FIG. 24  is a diagram illustrating an example when errors are displayed; 
         FIG. 25  is a flowchart illustrating an example of a procedure of a still image data acquiring process; 
         FIG. 26  is a flowchart illustrating an example of a procedure of a still image data providing process; 
         FIG. 27  is a block diagram illustrating an example of a hardware configuration of an image forming apparatus according to a second embodiment; 
         FIG. 28  is a diagram illustrating an example of an application setting screen; 
         FIG. 29  is a schematic diagram illustrating an example of a data configuration of application setting information; 
         FIG. 30  is a flowchart illustrating an example of a procedure of an application setting process; and 
         FIG. 31  is a flowchart illustrating an example of a procedure of an application startup process. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preferred embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. In the present embodiments, a reception device and a transmission device according to the present invention are applied to an image forming apparatus. However, the apparatuses to which the reception device and the transmission device according to the present invention can be applied are not limited thereto. In the embodiments described below, image data is a concept including moving image data and still image data. If the moving image data and the still image data need not to be distinguished from each other, they are simply referred to as image data. 
     First Embodiment 
       FIG. 1  is a diagram illustrating a configuration example of an image data transmission and reception system  1  according to the first embodiment. As illustrated in  FIG. 1 , the image data transmission and reception system  1  has a plurality of image forming apparatuses  2 . Each of the image forming apparatuses  2  is connected to a network N such as a local area network (LAN) or the Internet, and configured to be communicable with each other. The number of the image forming apparatus  2  connected to the network N is optional. 
       FIG. 2  is a diagram illustrating an example of an external configuration of the image forming apparatus  2 . As illustrated in  FIG. 2 , the image forming apparatus  2  includes a main body unit  10 , a camera unit  20 , and an operation unit  30 . The main body unit  10  has a paper feeding unit  11  that supplies a transfer sheet, and a printing unit  12  that forms an image on the transfer sheet fed from the paper feeding unit  11 . When the image is formed on the transfer sheet, the printing unit  12  ejects the transfer sheet onto a paper ejection table  13  provided in the middle of the main body unit  10  via a paper ejection port, which is not illustrated. In the configuration of  FIG. 2 , there are three paper feeding units  11 . However, the number of the paper feeding unit  11  is not limited thereto. A method of feeding paper by the paper feeding unit  11  and a method of forming an image by the printing unit  12  are optional, and known techniques such as an electrophotography method and an inkjet method may be used. 
     A document platen  15  is provided on an upper surface  14  of the main body unit  10 . A document or an object the image of which is to be picked up by the camera unit  20  is placed on the document platen  15 . The shape and configuration of the document platen  15  is not limited to the example in  FIG. 2 . For example, as illustrated in  FIG. 3 , the document platen  15  may be connected to the upper surface  14  of the main body unit  10  using a hinge, a slide mechanism, and the like, thereby extending the area of the document platen  15 . 
       FIG. 3  is a diagram illustrating another example of the external configuration of the image forming apparatus  2 . In  FIG. 3 , the right edge of the document platen  15  is connected to the left edge of the upper surface  14  by a hinge, and the document platen  15  is opened using the left edge of the upper surface  14  as a fulcrum. Here, it is preferable that the upper surface  14  and the document platen  15  are connected so that the surface thereof becomes flat. In this case, the area of a flat surface formed by the upper surface  14  and the document platen  15  is larger than that in  FIG. 2 . Hence, by using the whole flat surface formed by the upper surface  14  and the document platen  15  as the document platen  15 , it is possible to extend the area of the document platen  15 . 
     The color and material of the surface of the document platen  15  (upper surface  14 ) are optional. For example, by adhering a synthetic resin sheet and the like onto the surface of the document platen  15 , it may be used as a whiteboard so that the user can draw images and write words on its surface, or erase the images and words thereon. 
     The camera unit  20  is mounted on a support post  16  that stands on the main body unit  10 . The camera unit  20  includes an image sensor such as a charge-coupled device (CCD) and a complementary metal oxide semiconductor (CMOS), and picks up images of various objects. It is preferable that the camera unit  20  has a contrast AF (autofocus) function. 
     The image pickup direction of the camera unit  20  is changeable in the panning direction (horizontal direction) and in the tilting direction (vertical direction), by a driving mechanism, which is not illustrated, provided on the support post  16 . For example, when the image pickup direction is directed toward the document platen  15 , the camera unit  20  picks up an image of an article placed on the document platen  15  or a word and the like written on the document platen  15 . When the image pickup direction is directed toward the front of the main body unit  10  (front side of the diagram), the camera unit  20  picks up an image of a user and the like positioned in front of the main body unit  10 . 
     In the main body unit  10 , the position of the support post  16  is optional. However, it is preferable that the support post  16  is provided at the position where the camera unit  20  can pick up the image of the entire surface of the document platen  15 . It is also possible to configure the support post  16  to be telescopic, so that the camera unit  20  may be movable in the vertical direction. 
     The operation unit  30  is mounted on a support post  17  extended from the main body unit  10 . The operation unit  30  includes a display device  31  such as a liquid crystal display (LCD) and a touch panel  32  provided on the display surface of the display device  31 . 
     The device configuration of the image forming apparatus  2  is not limited to those in  FIG. 2  and  FIG. 3 . For example, as illustrated in  FIG. 4 , the image forming apparatus  2  may include a scanner unit  40  such as a sheet feed scanner. Here,  FIG. 4  is a diagram illustrating still another example of the external configuration of the image forming apparatus  2 . In  FIG. 4 , the scanner unit  40  is provided on a space portion  14   a  on the upper surface  14  illustrated in  FIG. 2 . The paper ejection direction of the scanner unit  40  is optional, and the paper may be ejected in the direction toward the document platen  15  or in the downward direction (rightward direction of the main body unit  10 ). 
     An internal configuration of the image forming apparatus  2  will now be described.  FIG. 5  is a block diagram illustrating an example of a hardware configuration of the image forming apparatus  2 . As illustrated in  FIG. 5 , the image forming apparatus  2  includes a system controller  51 . The system controller  51  has a computer configuration including a central processing unit (CPU), a System-on-a-Chip (SoC), read-only memory (ROM), random-access memory (RAM), and the like. The system controller  51  integrally controls the operation of the image forming apparatus  2 . More specifically, the system controller  51  causes its own device to operate as an image data transmission device, by functioning as a first generation unit, a distribution unit, a first reception unit, a second generation unit, and a first transmission unit. The system controller  51  also causes its own device to operate as an image data reception device, by functioning as a second reception unit, a display controlling unit, a receiving unit, a second transmission unit, and a third reception unit. 
     Various interfaces such as an input/output interface (I/F)  52 , an image input I/F  53 , an image output I/F  54 , a network I/F  55 , and a fax I/F  56  are connected to the system controller  51 . 
     The input/output I/F  52  is a general input/output interface that meets a predetermined standard such as a universal serial bus (USB). The image input I/F  53  is an interface for inputting an image (video) signal. For example, the image input I/F  53  is connected to the camera unit  20  and the scanner unit  40 , which will be described below. The image output I/F  54  is an interface for outputting an image (video) signal. For example, the image output I/F  54  is connected to the display device  31  of the operation unit  30 . The network I/F  55  is a network interface connectable to the network N. The fax I/F  56  is a fax model and a network interface that meets a data communication standard such as the EIA-592. 
     A storage unit  57  is connected to the system controller  51 . The storage unit  57  is a storage device such as a hard disk drive (HDD) and a solid-state drive (SSD). The storage unit  57  stores therein various programs such as an operating system, various programs (applications) for implementing various functions, which will be described below, and various types of data. 
     A camera position detection unit  58 , a camera position changing unit  59 , a human body detection unit  60 , a sound input/output unit  61 , and the like are also connected to the system controller  51 , in addition to the printing unit  12 , the camera unit  20 , and the scanner unit  40  described above. The camera position detection unit  58  and the camera position changing unit  59  configure a driving mechanism at the support post  16  described above. 
     For example, the camera position detection unit  58  is a gyro sensor, and detects the orientation (image pickup direction) of the camera unit  20 . The camera position changing unit  59  includes a monitor and the like, which are not illustrated, and moves the image pickup direction of the camera unit  20  in the panning direction (horizontal direction) and in the tilting direction (vertical direction). The image pickup direction of the camera unit  20  is not limited to the horizontal direction or the vertical direction, but it may also be the front direction or the rear direction. A method for detecting the image pickup direction of the camera unit  20  is optional, and for example, known techniques such as an encoder pulse may be used for detection. The image pickup direction of the camera unit  20  may be automatically changed by the camera position changing unit  59 , according to the control of the system controller  51 , or the user can change it manually. The human body detection unit  60  is a human body detection sensor such as an infrared ray sensor, and detects when the user comes close to the image forming apparatus  2 . The sound input/output unit  61  includes a sound collection device such as a microphone and a sound output device such as a speaker, and performs input and output of sound data. 
     An operation unit controller  62  is also connected to the system controller  51 . The operation unit controller  62  has a computer configuration including the CPU, the SoC, the ROM, the RAM, and the like, and receives a display control of the display device  31  and an input of a user operation via the touch panel  32 , by collaborating with the system controller  51 . 
       FIG. 6  is a block diagram illustrating an example of a functional configuration of the image forming apparatus  2 . As illustrated in  FIG. 6 , the system controller  51  includes various management units, controlling units, and the like. The management units and the controlling units such as these are implemented in a software manner by executing the programs stored in the storage unit  57 , or implemented in a hardware manner by a dedicated processor in the system controller  51 . 
     A resource management unit  71  manages resources commonly used by applications such as the printing unit  12 , the camera unit  20 , and the scanner unit  40 . A state management unit  72  manages the state of its own device (image forming apparatus  2 ). For example, the state management unit  72  monitors the states of the paper feeding unit  11  and the printing unit  12 , and the state of each application. When an inactive state continues for a predetermined time, the state management unit  72  switches to an energy saving operation such as a standby mode. 
     An operation unit input/output management unit  73  is a function unit that manages the coordination with the operation unit controller  62 . For example, the operation unit input/output management unit  73  outputs image data and the like to the operation unit  30 , and also receives an input of operational data indicating the operation contents of the operation unit  30 . 
     A camera controlling unit  74  performs various controls according to the image pickup of the camera unit  20  such as a focus control of the camera unit  20  and controlling an image sensor. A camera position controlling unit  75  changes the image pickup direction of the camera unit  20 , by driving the camera position changing unit  59  based on the detection results obtained by the camera position detection unit  58 . For example, when a copy button B 116 , which will be described below, is operated, the camera position controlling unit  75  drives the camera position changing unit  59  so that the image pickup direction of the camera unit  20  is directed toward the document platen  15 . When a conference button B 124 , which will be described below, is operated, the camera position controlling unit  75  drives the camera position changing unit  59  so that the image pickup direction of the camera unit  20  is directed toward the front direction of the main body unit  10 . 
     A print controlling unit  76  prints an image and the like on a transfer sheet by controlling the paper feeding unit  11  and the printing unit  12 . A scanner controlling unit  77  causes the scanner unit  40  to perform a scanning operation, by controlling the scanner unit  40 . 
     An input/output I/F controlling unit  78  controls the input and output of data to and from an external device connected to the input/output I/F  52 , by collaborating with the input/output I/F  52 . An image input I/F controlling unit  79  controls an input of image data via the image input I/F  53 , by collaborating with the image input I/F  53 . An image output I/F controlling unit  80  controls an output of image data via the image output I/F  54 , by collaborating with the image output I/F  54 . A network I/F controlling unit  81  controls data communication with an external device (other image forming apparatus  2 ) connected to the network N, by collaborating with the network I/F  55 . A fax I/F controlling unit  82  controls data communication with an external device connected to a fax line, by collaborating with the fax I/F  56 . A sound input/output I/F controlling unit  83  controls the input and output of sound data, by collaborating with the sound input/output unit  61 . 
     A storage controlling unit  84  controls writing (storing) of various types of data to a storage device such as the storage unit  57 , and reading of various types of data from the storage device. A history management unit  85  records the history of a user operation performed via the operation unit  30 , the history of changing state of its own device, and the like. 
     An image processing controlling unit  86  performs various types of image processing such as a resolution conversion on image data input from the camera unit  20 , the scanner unit  40 , and the like. The image processing controlling unit  86  also performs various types of image processing such as a resolution conversion on image data stored in the RAM, the storage unit  57 , and the like. 
     The system controller  51  has various types of function units, by executing various applications stored in the storage unit  57 . These function units implement a predetermined function according to an application, by collaborating with various management units and controlling units described above. 
     A copy function unit  87  implements a copy function of printing image data input from the camera unit  20 , the scanner unit  40 , and the like onto a transfer sheet. A fax function unit  88  implements a fax function of transmitting image data input from the camera unit  20 , the scanner unit  40 , and the like to an external device connected to a fax line. A scanner function unit  89  implements a scanner function of saving image data input from the camera unit  20 , the scanner unit  40 , and the like to an external device connected to the storage unit  57  and the input/output I/F  52 . A printer function unit  90  implements a printer function of printing image data input from the camera unit  20  and the like onto a transfer sheet. An optical character reader (OCR) function unit  91  implements an OCR function of identifying a character string included in image data input from the camera unit  20 , the scanner unit  40 , and the like, and converts it into character data. 
     A search function unit  92  implements a search function of searching data that corresponds to the condition of a search key input via the operation unit  30  and the like, from various types of data saved in the storage unit  57  and the like. A special copy function unit  93  implements a special copy function of printing image data input from the camera unit  20 , the scanner unit  40 , and the like by enlarging or reducing its size, or the like. An accumulation function unit  94  implements an accumulation function of accumulating (saving) image data and the like transmitted from an external device (other image forming apparatus  2 ) into the storage device such as the storage unit  57 . 
     A conference function unit  95  implements a video conference function of conducting a video conference with the other image forming apparatus  2 . An observation function unit  96  implements an observation function of observing (for example, fixed point observation) an object using the camera unit  20 . A presentation function unit  97  implements a presentation function of transmitting image data picked up by the camera unit  20 , to the other image forming apparatus  2  connected to the network N. 
     The operation unit controller  62  includes a display controlling unit  101 , an input controlling unit  102 , and a user interface (UI) controlling unit  103 . The controlling units such as these are implemented in a software manner by executing the programs stored in the ROM and the like of the operation unit controller  62 , or implemented in a hardware manner by a dedicated processor in the operation unit controller  62 . 
     The display controlling unit  101  controls the display of the display device  31 . The input controlling unit  102  converts the physical user operation (input) on the touch panel  32  to a logical input indicating the operation content. The UI controlling unit  103  displays various UIs according to the operation of the image forming apparatus  2  on the display device  31 , by collaborating with the display controlling unit  101 . For example, the UI controlling unit  103  displays an initial screen illustrated in  FIG. 7  on the display device  31 , as a home screen according to the operation of the image forming apparatus  2 . 
     Here,  FIG. 7  is a diagram illustrating an example of an initial screen displayed on the display device  31  of the operation unit  30 . As illustrated in  FIG. 7 , an initial screen G 1  has various operating elements according to the operations of the image forming apparatus  2 . For example, a camera button B 111  is an operating element for activating the camera unit  20 . An initial setting button B 112  is an operating element for changing the setting of the image forming apparatus  2 . A system state button B 113  is an operating element for displaying the states such as the remaining amount of toner and the accumulation state of image data. A login/logout button B 114  is an operating element for identifying the user. An erasure button B 115  is an operating element for erasing data stored temporarily. 
     The initial screen G 1  also has operating elements (buttons) for activating various applications (function units). For example, the copy button B 116  is an operating element for activating the copy function (copy function unit  87 ). A fax button B 117  is an operating element for activating the fax function (fax function unit  88 ). A scanner button B 118  is an operating element for activating the scanner function (scanner function unit  89 ). A printer button B 119  is an operating element for activating the printer function (printer function unit  90 ). An OCR button B 120  is an operating element for activating the OCR function (OCR function unit  91 ). A search button B 121  is an operating element for activating the search function (search function unit  92 ). A special copy button B 122  is an operating element for activating a special copy function (special copy function unit  93 ). An accumulation button B 123  is an operating element for activating the accumulation function (accumulation function unit  94 ). A conference button B 124  is an operating element for activating the conference function (conference function unit  95 ). An observation button B 125  is an operating element for activating the observation function (observation function unit  96 ). A presentation button B 126  is an operating element for activating the presentation function (presentation function unit  97 ). 
     When an operating element on the initial screen G 1  is operated, the UI controlling unit  103  displays a UI corresponding to the operating element. The UIs other than the initial screen GI displayed by the UI controlling unit  103  will be described below. 
     Hereinafter, characteristic operations of the image forming apparatus  2  will be described. An operation according to the control of the focus position of the camera unit  20  will now be described, as the first characteristic of the image forming apparatus  2 . 
     Upon receiving an operation of the camera button B 111  on the initial screen G 1  described above, the system controller  51  starts to pick up an image, by operating the camera unit  20 . The system controller  51  also displays a camera image screen illustrated in  FIG. 8  on the display device  31 , by collaborating with the UI controlling unit  103 . 
       FIG. 8  is a diagram illustrating an example of a camera image screen. As illustrated in  FIG. 8 , a camera image screen G 2  has a return button B 21  and a focus button B 22 , in addition to the login/logout button B 114  and the buttons B 116  to B 126  described above. Here, the return button B 21  is an operating element for returning to the initial screen G 1 . The focus button B 22  is an operating element for setting the focus position of the camera unit  20 . The camera image screen G 2  also has an area A 1 , where image data picked up by the camera unit  20  is displayed as a picked up image. 
     Here,  FIG. 9  is a diagram illustrating an example of a relation between the camera unit  20  and the document platen  15 . In  FIG. 9 , as illustrated in  FIG. 3 , the document platen  15  is in an open state. An area A 21  is an image pickup range of the camera unit  20 . An area A 22  is a range of a document size A 6 Y, and an area A 23  is a range of a document size A 6 T (Y is a landscape orientation and T is a portrait orientation). An area A 24  is a range of a document size A 5 Y, and an area A 25  is a range of a document size A 5 T. An area A 26  is a range of a document size A 4 Y, an area A 27  is a range of a document size A 4 T, and an area A 28  is a range of a document size A 3 . The standard position to place a document on the document platen  15  is at a point P 1  at the upper right hand side in  FIG. 9 . 
     For example, when a document having the document size A 6 Y is placed on the document platen  15 , if the focus position of the camera unit  20  is set at the position appropriate for the document size A 3  (approximately in the center of the area A 28 ), there is a possibility that the picked up image of the document may be unclear. Thus, in the image forming apparatus  2 , the focus position of the camera unit  20  can be changed to any position. 
     More specifically, when the focus button B 22  illustrated in  FIG. 8  is operated, the system controller  51  shifts to an operation mode for specifying a focus position, by collaborating with the camera controlling unit  74 . Under this operation mode, for example, the system controller  51  displays a guide image that supports specifying the focus position on the area A 1 . 
       FIG. 10  is a diagram illustrating an example of a guide image. For example, the guide image is transparently displayed on the picked up image in the area A 1 .  FIG. 10  illustrates a grid pattern that divides the area A 1 , in other words, the image pickup range (area A 21 ) of the camera unit  20  into small areas. The operating elements (areas surrounded by a dotted line) are arranged at the focus position corresponding to each of the areas A 22  to A 28 . The reference numerals and characters (A to H and  1  to  6 ) at the periphery of the guide image are coordinates for indicating the small areas. The system controller  51  displays the focus position currently being set in a superimposed manner, on the picked up image in the area A 1 . 
     When the guide image of  FIG. 10  is used, the user of the image forming apparatus  2  can indicate the focus position of the camera unit  20 , by selectively operating the operating element displayed on the area A 1 . For example, upon receiving an operation of the operating element “A 6 T”, the input controlling unit  102  notifies the system controller  51  of the coordinates (G, 2) corresponding to the position of the operating element. The system controller  51  then sets the focus position of the camera unit  20  to the position corresponding to the coordinates (G, 2), by collaborating with the camera controlling unit  74 . The changing method of the focus position is optional, and known techniques may be used. 
     The guide image is not limited to the example in  FIG. 10 , and another mode may be adopted. In the image forming apparatus  2  according to the present embodiment, the object of the camera unit  20  is not limited to a document. Thus, the focus position may not match with the document size. Hence, for example, as illustrated in  FIG. 11 , a guide image having only a grid pattern may be displayed on the area A 1 . 
       FIG. 11  is a diagram illustrating another example of the guide image. In  FIG. 11 , a guide image of a grid pattern is transparently displayed on the picked up image (image of a flower) displayed on the area A 1 . In this example, the user of the image forming apparatus  2  can indicate the focus position of the camera unit  20 , by specifying a desired position on the area A 1  through a touch operation. For example, upon receiving an operation to specify a position P 2 , the system controller  51  sets the focus position of the camera unit  20  at the position corresponding to the position P 2 . It is preferable that the guide images in  FIG. 10  and  FIG. 11  are configured to be switchable. For example, they may be switched by a toggle operation using the focus button B 22 . An operating element dedicated for switching the screen may be provided. It is also possible to perform an operation for specifying the focus position directly on the picked up image in the area A 1 , without displaying the guide image. 
     In the examples in  FIG. 10  and  FIG. 11 , the camera image screen G 2  is used for specifying the focus position. However, it is not limited thereto, and the focus position may be specified from another screen. More specifically, upon receiving an operation of the focus button B 22 , the system controller  51  displays a screen for specifying a focus position (focus position specification screen) on the display device  31 , by collaborating with the UI controlling unit  103 . 
       FIG. 12  is a diagram illustrating an example of a focus position specification screen. As illustrated in FIG.  12 , a focus position specification screen G 3  has a return button B 31 , a confirmation button B 32 , and a reset button B 33 , in addition to the login/logout button B 114  described above. The return button B 31  is an operating element for returning to the preceding screen. The confirmation button B 32  is an operating element for confirming the focus position. The reset button B 33  is an operating element for resetting the focus position set temporarily. The focus position specification screen G 3  also has an area A 3 . The system controller  51  displays an image picked up by the camera unit  20  on the area A 3 . The system controller  51  also displays the focus position currently being set in a superimposed manner, on the picked up image in the area A 3 . 
     In the focus position specification screen G 3 , for example, the system controller  51  displays the guide image described above on the area A 3 , by collaborating with the UI controlling unit  103 . The user of the image forming apparatus  2  can indicate the focus position of the camera unit  20 , by specifying a desired position on the area A 3  through a touch operation, in the same way as described above. For example, upon receiving an operation to specify the position P 2 , the system controller  51  temporarily sets the focus position of the camera unit  20  at the position corresponding to the position P 2 . When the confirmation button B 32  is operated at this state, the system controller  51  confirms the focus position set temporarily as the formal setting, and returns to the preceding screen by erasing the focus position specification screen G 3 . When the reset button B 33  is operated, the system controller  51  resets the focus position set temporarily, and returns the setting to a default focus position determined in advance. 
     The focus button B 22  may be provided on the other screen instead of the camera image screen G 2 . For example, the focus button B 22  may be provided on the UIs of various functions (copy function, conference function, presentation function, and the like) that use the picked up image of the camera unit  20 . 
     Here,  FIG. 13  is a diagram illustrating an example of a copy screen according to a copy function. A copy screen G 4  is a UI displayed when the copy button B 116  on the initial screen G 1  in  FIG. 7  or on the camera image screen G 2  in  FIG. 8  is operated. 
     As illustrated in  FIG. 13 , the copy screen G 4  has a return button B 41 , an input source selection button B 42 , a document size specification button B 43 , numerical keys B 44 , a start button B 45 , and a clear button B 46 , in addition to the login/logout button B 114  and the focus button B 22  described above. The return button B 41  is an operating element for returning to the preceding screen (initial screen G 1  or camera image screen G 2 ). The input source selection button B 42  includes a camera button B 421  that specifies the camera unit  20  and a scanner button B 422  that specifies the scanner unit  40 . When either of the camera button B 421  or the scanner button B 422  is selected, the copy function unit  87  copies and prints image data, by using the image data input from the selected device. The document size specification button B 43  is an operating element for specifying the size of a document to be copied. The numerical keys B 44  are operating elements for specifying the number of sheets to be copied and the like. The start button B 45  is an operating element to start copying. The clear button B 46  is an operating element for clearing the setting content set via the document size specification button B 43  and the like. 
     The copy screen G 4  has an area A 4 . When the camera button B 421  is selected, an image picked up by the camera unit  20  is displayed on the area A 4 . When the scanner button B 422  is operated, an image scanned by the scanner unit  40  is displayed on the area A 4 . 
     In the copy screen G 4 , when the camera button B 421  is selected and the focus button B 22  is operated, the system controller  51  transparently displays the guide image on the picked up image in the area A 4  in the same way as described above. The system controller  51  then changes the focus position of the camera unit  20 , through a touch operation on the area A 4 . 
     When the copy screen G 4  is used, the focus position of the camera unit  20  may be changed according to the document size specified via the document size specification button B 43 . For example, when this configuration is adopted, the storage unit  57  of the image forming apparatus  2  stores in advance a focus position setting table and the like that defines the focus position of each document size, and the focus position of the camera unit  20  is determined based on the focus position setting table. 
     Here,  FIG. 14  is a schematic diagram illustrating an example of a data configuration of a focus position setting table. As illustrated in  FIG. 14 , a focus position setting table T 1  stores therein coordinates of a focus position for each document size, corresponding to the document size. For example, the coordinates (G, 2) are associated with the document size of A 6 T. The coordinates (D, 4) are associated with the document size of A 3 . Each of the coordinates in the focus position setting table T 1  corresponds to the position coordinates on the guide image illustrated in  FIG. 10 . 
     When the camera button B 421  is selected and the document size is specified by the document size specification button B 43 , the system controller  51  reads out the coordinates of the focus position corresponding to the document size, from the focus position setting table T 1 . The system controller  51  then sets the focus position of the camera unit  20 , to the coordinates being read out. 
     An operation of the image forming apparatus  2  according to the changing in the setting of the focus position described above will now be explained. 
     A procedure of an operation receiving process performed while the camera image screen G 2  is displayed, will now be described with reference to  FIG. 15  and  FIG. 16 . Here,  FIG. 15  is a flowchart illustrating an example of a procedure of an operation receiving process. In the present process, the focus position specification screen G 3  is displayed when the focus button B 22  is operated. 
     The system controller  51  displays the initial screen G 1  on the display device  31  (step S 11 ). Then, the system controller  51  stands by until the camera button B 111  is operated (No at step S 12 ). Upon receiving an operation of the camera button B 111  (Yes at step S 12 ), the system controller  51  starts the camera unit  20  (step S 13 ), and displays the camera image screen G 2  on the display device  31  (step S 14 ). 
     The system controller  51  then determines whether the focus button B 22  is operated (step S 15 ). Upon receiving an operation of the focus button B 22  (Yes at step S 15 ), the system controller  51  executes a focus position setting process (step S 16 ). 
       FIG. 16  is a flowchart illustrating an example of a procedure of a focus position setting process. The system controller  51  displays the focus position specification screen G 3  on the display device  31  (step S 21 ). The system controller  51  then displays the focus position currently being set on the picked up image in the area A 4  in a superimposed manner (step S 22 ). At the initial state, a default focus position set in advance is displayed on the area A 4 . 
     Then, the system controller  51  stands by for an operation from the user (No at step S 23 ; No at step S 26 ; and No at step S 28 ). Upon receiving an operation to specify the focus position on the area A 4  (Yes at step S 23 ), the system controller  51  acquires the specified position coordinates (step S 24 ). The system controller  51  then temporarily sets the focus position of the camera unit  20  based on the acquired position coordinates (step S 25 ), and returns to step S 22 . 
     If the reset button B 33  is operated (Yes at step S 26 ), the system controller  51  resets the focus position currently being set (step S 27 ). The system controller  51  then displays the default focus position on the area A 4 , by returning to step S 22 . 
     If the confirmation button B 32  is operated (Yes at step S 28 ), the system controller  51  confirms (sets) the focus position currently being set (step S 29 ), and returns to the original process. The focus position set by this focus position setting process will be passed on to the subsequent processes. 
     Returning to  FIG. 15 , when the focus position setting process is finished, the system controller  51  returns to step S 15 . At step S 15 , if the focus button B 22  is not operated (No at step S 15 ), the system controller  51  determines whether the elapsed time from when the preceding operation is performed has reached a predetermined timeout time (step S 17 ). If it is determined that it has not reached the timeout time (No at step S 17 ), the system controller  51  determines whether an application startup operation for activating the application is performed (step S 18 ). 
     At step S 18 , upon receiving the application startup operation (Yes at step S 18 ), the system controller  51  activates the indicated application (function unit) by starting it (step S 19 ), and terminates the present process. After the application is started, the system controller  51  displays the UI according to the application on the display device  31 . 
     At step S 17 , upon determining that it has reached the timeout time (Yes at step S 17 ), the system controller  51  displays the initial screen G 1  again, by returning to step S 11 . At step S 18 , if the application startup operation has not been received (No at step S 18 ), the system controller  51  stands by for an operation from the user until it has reached the timeout time, by returning to step S 15 . 
     A process for setting the focus position performed via the copy screen G 4  will now be described with reference to  FIG. 17 . Here,  FIG. 17  is a flowchart illustrating an example of a procedure of a document size changing process. As a premise of the present process, it is assumed that the copy screen G 4  is displayed on the display device  31  (step S 31 ). 
     The system controller  51  stands by until an operation for changing the document size is performed on the copy screen G 4  (No at step S 32 ). Here, upon receiving the changing operation of the document size via the document size specification button B 43  (Yes at step S 32 ), the system controller  51  acquires the focus position corresponding to the document size, from the focus position setting table T 1  (step S 33 ). The system controller  51  then sets the focus position acquired at step S 33  to the camera unit  20  (step S 34 ), and terminates the present process. 
     As described above, according to the first characteristic of the image forming apparatus  2 , the focus position of the camera unit  20  can be set to any position. Thus, it is possible to pick up images of various objects such as a document in a suitable state. According to the first characteristic of the image forming apparatus  2 , the focus position is changed according to the changing operation of the document size. Thus, it is possible to pick up an image of a document of each size in a suitable state. 
     Next, an operation according to the exchange of image data with the other image forming apparatus  2  will be described as the second characteristic of the image forming apparatus  2 . 
     In the image forming apparatus  2 , when the conference button B 124  or the like illustrated in the initial screen G 1  (refer to  FIG. 7 ) is operated, it is possible to exchange image data and sound data with the other image forming apparatus  2 . 
     More specifically, upon receiving an operation of the conference button B 124 , the system controller  51  operates the camera unit  20 , and distributes (transmits) the moving image data picked up by the camera unit  20  together with the sound data, to the other image forming apparatus  2 . The system controller  51  also receives the moving image data and the sound data transmitted from the other image forming apparatus  2 . 
     Here, the system controller  51  controls to temporality store (retain) the moving image data (first moving image data) picked up by the camera unit  20  in the storage medium such as the RAM. From the temporarily stored moving image data, the system controller  51  controls to generate moving image data (second moving image data) for streaming distribution the data quantity of which such as resolution is reduced. The system controller  51  then controls the moving image data to be distributed to the other image forming apparatus  2 . Consequently, the image quality of the moving image data to be distributed from the own device to the other image forming apparatus  2 , is lower than the original image quality of the moving image data picked up by the camera unit  20  of the own device. 
     The system controller  51  also displays a UI for the video conference (conference screen G 5 ) on the display device  31 , by collaborating with the UI controlling unit  103 . Here,  FIG. 18  is a diagram illustrating an example of the conference screen G 5 . The conference screen G 5  has an area A 5 . The system controller  51  displays the moving image data picked up by the camera unit  20  of the own device and the moving image data transmitted from the other image forming apparatus  2  communicating with the own device, on the area A 5 , as the picked up images of the image forming apparatuses  2 . In  FIG. 18 , it is assumed that a video conference is performed among three image forming apparatuses  2  including the own device. Thus, three picked up images M 1  to M 3  picked up by the three image forming apparatuses  2  including the own device are displayed on the area A 5 . It is also possible not to display the picked up image of the own device, on the area A 5 . 
     The picked up images displayed on the area A 5  are configured to be selectable. The user can select one or all of the picked up images, for example, through a touch operation on the picked up images. Upon receiving the selection of the picked up image through the operations of various mode buttons, which will be described below, the system controller  51  sets the selected picked up image or the image forming apparatus  2  that picks up the picked up image, as an object to be processed corresponding to the mode button. 
     The conference screen G 5  has a return button B 51 , in addition to the login/logout button B 114  and the focus button B 22  described above. Here, the return button B 51  is an operating element for returning to the preceding screen. 
     The conference screen G 5  also has various mode buttons B 52  to B 57 . The display mode button B 52  is an operating element for changing the display mode of the picked up image to be displayed on the area A 5 . For example, the UI controlling unit  103  changes the display position and the display sequence of the picked up images, every time the display mode button B 52  is pressed. 
     A connection mode button B 53  is an operating element for specifying the other image forming apparatus  2 , which is to be a communication destination. Upon receiving an operation of the connection mode button B 53 , the system controller  51  displays a screen (not illustrated) for specifying the communication destination, and establishes communication with the specified other image forming apparatus  2 . For example, such a screen has a screen configuration that can select the image forming apparatus  2  as a communication partner, from the image forming apparatuses  2  connected to the network N. 
     A print mode button B 54  is an operating element for printing the picked up image displayed on the area A 5 . Upon receiving an operation of the print mode button B 54 , the system controller  51  displays a print mode screen as illustrated in  FIG. 19 . Here,  FIG. 19  is a diagram illustrating an example of a print mode screen. Upon receiving an operation of the print mode button B 54 , the system controller  51  displays a print mode screen G 6  on the conference screen G 5 . At this state, for example, the user can specify the picked up image to be printed, by selecting a picked up image displayed on the area A 5 . 
     The print mode screen G 6  has an area A 6  for indicating the printing state. In  FIG. 19 , “being previewed” is displayed on the area A 6  as the printing state. The print mode screen G 6  also includes a sheet-number setting button B 61 , a clear button B 62 , a size setting button B 63 , a print button B 64 , and a return button B 65 . 
     The sheet-number setting button B 61  is an operating element for setting the number of sheets to be printed. For example, the sheet-number setting button B 61  is configured so that the number of sheets to be printed is increased one by one, every time it is operated (pressed). The clear button B 62  is an operating element for clearing the number of sheets to be printed or to interrupt printing. The size setting button B 63  is an operating element for setting the sheet size. For example, the size setting button B 63  is configured so that the setting of the sheet size is switched by a toggle operation. The print button B 64  is an operating element for executing printing. The return button B 65  is an operating element for erasing the print mode screen G 6 . 
     Returning to  FIG. 18 , a transfer mode button B 55  is an operating element for transferring various types of data (conference materials and the like) stored in the storage unit  57  and the like to the other image forming apparatus  2 . Upon receiving an operation of the transfer mode button B 55 , the system controller  51  displays a screen (not illustrated) for specifying the data to be transferred. The system controller  51  then transfers the data to be transferred to the other image forming apparatus  2  selected via the picked up image on the area A 5 . 
     An accumulation mode button B 56  is an operating element for accumulating the picked up images displayed on the area A 5 . Upon receiving an operation of the accumulation mode button B 56 , the system controller  51  displays an accumulation mode screen as illustrated in  FIG. 20 . Here,  FIG. 20  is a diagram illustrating an example of an accumulation mode screen. Upon receiving an operation of the accumulation mode button B 56 , the system controller  51  displays an accumulation mode screen G 7  on the conference screen G 5 . At this state, for example, the user can specify the picked up image to be accumulated, by selecting the picked up image displayed on the area A 5 . 
     The accumulation mode screen G 7  has an area A 7  for indicating the accumulation state. In  FIG. 20 , “being previewed” is displayed on the area A 7 , as the accumulation state. The accumulation mode screen G 7  also has a size setting button B 71 , a saving destination selection button B 72 , a save button B 73 , and a return button B 74 . 
     The size setting button B 71  is an operating element for setting the image size. The size setting button B 71  corresponds to a second specification unit in the present embodiment. For example, the size setting button B 71  is configured so that the setting of the image size is switched by a toggle operation. The saving destination selection button B 72  is an operating element for indicating the accumulation (saving) destination of image data (still image data). For example, the saving destination selection button B 72  is configured so that the saving destination device such as the storage unit  57  and a device connected to the input/output I/F  52  is switched by a toggle operation. The save button B 73  is an operating element for accumulating (saving) image data (still image data). The return button B 74  is an operating element for erasing the accumulation mode screen G 7 . 
     Returning to  FIG. 18 , the conference screen G 5  has an image quality setting button B 57 . The image quality setting button B 57  is an operating element for setting the image quality of image data (still image data). Upon receiving an operation of the image quality setting button B 57 , the system controller  51  displays an image quality setting mode screen as illustrated in  FIG. 21 . Here,  FIG. 21  is a diagram illustrating an example of an image quality setting mode screen. Upon receiving an operation of the image quality setting button B 57 , the system controller  51  displays an image quality setting mode screen G 8  on the conference screen G 5 . 
     The image quality setting mode screen G 8  has an area A 8  for indicating the picked up image to be set. As illustrated in  FIG. 21 , the user can specify the picked up image to be set, by selecting one of the picked up images displayed on the area A 5 . In  FIG. 21 , a picked up image M 1  at the upper left is an “input  1 ”, a picked up image M 2  at the upper right is an “input  2 ”, and a picked up image M 3  at the lower center is an “input  3 ”, and in the example, the “input  1 ” is selected. 
     The image quality setting mode screen G 8  has four image quality specification buttons B 81  to B 84  to specify the image quality. The image quality specification buttons B 81  to B 84  correspond to a first specification unit in the present embodiment. In  FIG. 21 , four levels of image qualities of “low image quality”, “average”, “high image quality”, and “super-high image quality” can be specified. 
     In the print mode and the accumulation mode described above, upon receiving the selection operation of a picked up image to be printed or to be accumulated from the area A 5  (hereinafter, referred to as a trigger operation), the system controller  51  transmits an acquisition request for still image data to the image forming apparatus  2 , which is a transmission source of the picked up image. In other words, the trigger operation corresponds to an operation for acquiring still image data. Here, the system controller  51  may also include image quality information indicating the image quality set on the image quality setting mode screen G 8 , in the acquisition request. When the image size is set by the size setting button B 71  on the accumulation mode screen G 7 , the system controller  51  may include the image size information indicating the image size, in the acquisition request. 
     The system controller  51  at the side of the image forming apparatus  2  that receives the acquisition request generates still image data from the moving image data picked up by the camera unit  20 , and transmits it to the image forming apparatus  2  of the request source. Here, when the image quality information and the image size information are included in the acquisition request, the system controller  51  generates still image data of the image quality and image size indicated by the information, and transmits it to the image forming apparatus  2  of the request source. 
     For example, when the indicated image quality is the “super-high image quality”, the system controller  51  sets the still image data by extracting still image data of one frame from the moving image data picked up by the camera unit  20 . In this case, the image quality of the still image data is higher compared to the image quality of the moving image data to be distributed. When the indicated image quality is the “high quality”, “average”, or “low quality”, the system controller  51  sets the still image data by converting still image data of one frame extracted from the moving image data picked up by the camera unit  20 , to the resolution according to each image quality. If the image size is indicated, the system controller  51  converts the image size of the still image data extracted from the moving image data, to the indicated image size. If the image quality and image size are not indicated, the still image data extracted from the moving image data may be used as it is, or may convert it to a default resolution or image size determined in advance. If it is converted into a default resolution, it is preferable that the default resolution is higher than the resolution for streaming distribution. 
     At the side of the image forming apparatus  2  of the request source, upon receiving still image data, the system controller  51  temporarily stores the still image data in the RAM and the like, and displays it on the display device  31  as a preview. For example, the system controller  51  displays the acquired still image data on the area A 5 , instead of the corresponding picked up image. The system controller  51  then executes a process according to the operated mode button, on the acquired still image data. For example, when the print button B 64  described above is operated, the system controller  51  causes the printing unit  12  to print the acquired still image data. When the save button B 73  described above is operated, the system controller  51  saves the acquired still image data in the saving destination selected via the saving destination selection button B 72 . 
       FIG. 22  is a schematic diagram illustrating an example of data transfer according to the exchange of still image data. In  FIG. 22 , a chart illustrated between an image forming apparatus  2   a  and an image forming apparatus  2   b  is a flow of data between the two devices. The horizontal axis is a time axis indicating the time series, displaying the elapsed time from the left side to the right side. The vertical axis displays the data quantity to be transferred. Also, 1, 2, . . . M, M+1, . . . , N, N+1, . . . , P, P+1, . . . are time information indicating the timing (such as time code and frame number) of the picked up image (moving image data). It is assumed that the image forming apparatus  2   a  and the image forming apparatus  2   b  are transmitting and receiving moving image data for a video conference. It is also assumed that a measure for eliminating the time lag according to the transmission and reception of moving image data has been taken between the transmission side and the reception side. 
     When a trigger operation is performed at the specific timing M in the image forming apparatus  2   a , the system controller  51  of the image forming apparatus  2   a  generates an acquisition request according to the trigger operation, and transmits it to the image forming apparatus  2   b.    
     In the image forming apparatus  2   b , upon receiving the acquisition request at the timing N, the system controller  51  of the image forming apparatus  2   b  generates still image data of the frame distributed at the timing N. The system controller  51  of the image forming apparatus  2   b  then transmits (transfers) the generated still image data to the image forming apparatus  2   a.    
     In this manner, the image forming apparatus  2  of the distribution side that distributes moving image data can provide still image data of image quality (resolution and image size) different from that of the moving image data being distributed, to the image forming apparatus  2  of the reception side that receives the moving image data. In  FIG. 22 , the data is transferred between the two devices of the image forming apparatus  2   a  and the image forming apparatus  2   b . However, the same applies when the data is transferred among three or more devices. 
     In the configuration in  FIG. 22 , a time lag occurs between the operation timing (timing M) when the trigger operation is performed in the image forming apparatus  2   a  and the generation timing (timing N) when the still image data is generated in the image forming apparatus  2   b . Thus, it is possible to eliminate the time lag by including the time information indicating the timing when the trigger operation is performed in the acquisition request. Hereinafter, the configuration will be described with reference to  FIG. 23 . 
       FIG. 23  is a schematic diagram illustrating another example of the data transfer according to the exchange of still image data. The meanings of the horizontal axis, the vertical axis, and the like in  FIG. 23  are the same as those in  FIG. 22 . 
     When a trigger operation is performed at the specific timing M in the image forming apparatus  2   a , the system controller  51  of the image forming apparatus  2   a  generates an acquisition request including the time information indicating the timing M, and transmits it to the image forming apparatus  2   b.    
     In the image forming apparatus  2   b , upon receiving the acquisition request at the timing N, the system controller  51  of the image forming apparatus  2   b  generates still image data of the frame distributed at the timing M, based on the time information included in the acquisition request. The system controller  51  of the image forming apparatus  2   b  then transmits (transfers) the generated still image data to the image forming apparatus  2   a . If the present configuration is adopted, the image forming apparatus  2  that distributes the moving image data retains the moving image data of a predetermined period of time (such as ten seconds) picked up by the camera unit  20 , in the RAM and the like. A method for retaining the moving image data is optional, but for example, a ring buffer may be used so that the moving image data are sequentially retained in an overwriting manner. 
     In this manner, in the image forming apparatus  2 , the time information indicating the timing when the trigger operation is performed, is included in the acquisition request to be transmitted. Thus, it is possible to acquire the still image data of the moving image data displayed (distributed) at the timing. 
     If the moving image data (still image data) is not present at the timing indicated by the acquisition request (time information), the system controller  51  distributes error information indicating that effect, to the image forming apparatus  2  that transmitted the acquisition request. In this case, the still image data closest to the indicated timing or the still image data when the acquisition request is received, may be distributed together with the error information. 
     Similarly, if the still image data of the image quality indicated by the acquisition request (image quality information and image size) cannot be generated, the system controller  51  transmits error information indicating that effect, to the image forming apparatus  2  that transmitted the acquisition request. In this case, the still image data extracted from the moving image data or the still image data closest to the indicated image quality, may be generated and transmitted together with the error information. 
     In the image forming apparatus  2  that received error information, the error is displayed in association with the relevant picked up image on the conference screen G 5 , by collaborating with the UI controlling unit  103 . 
     Here,  FIG. 24  is a diagram illustrating an example of the conference screen G 5  when errors are displayed. In  FIG. 24 , it is assumed that an acquisition request for still image data is transmitted to the picked up images M 1  and M 3  on the area A 5 . Here, error information E 1 , which indicates that still image data is not present at the timing indicated by the acquisition request (time information), is displayed on the picked up image M 1 . In addition, error information E 2  indicating that still image data of the image quality indicated by the acquisition request (image quality information) is not present, is displayed on the picked up image M 3 . 
     In the explanation described above, the trigger operation to start acquiring still image data is operated by selecting the picked up image displayed on the area A 5 . However, it is not limited thereto. For example, an operation on the print mode button B 54  or the accumulation mode button B 56  may be a trigger operation. An operation on the print button B 64  or the save button B 73  may also be a trigger operation. 
     An operation of the image forming apparatus  2  according to the exchange of still image data described above will now be explained. 
     An operation of the image forming apparatus  2  at the side that receives still image data will now be described with reference to  FIG. 25 . Here,  FIG. 25  is a flowchart illustrating an example of a procedure of a still image data acquiring process. In the present process, still image data is acquired at the timing when the trigger operation is performed. In the present process, if still image data cannot be generated under the condition indicated by the acquisition request, substitute still image data is received together with error information. 
     As a premise of the present process, it is assumed that the conference screen G 5  is displayed on the display device  31 , and moving image data is exchanged (transmitted and received) with the other image forming apparatus  2  (step S 41 ). 
     The system controller  51  stands by until a trigger operation for acquiring still image data is performed (No at step S 42 ). Upon receiving the trigger operation (Yes at step S 42 ), the system controller  51  generates an acquisition request including the time information that indicates the timing when the trigger operation is performed, the image quality information, and the like, and transmits it to the other image forming apparatus  2  (step S 43 ). 
     The system controller  51  acquires still image data from the other image forming apparatus  2  (step S 44 ), as a response to the acquisition request. The system controller  51  then determines whether error information is added to the acquired still image data (step S 45 ). Here, if the error information is not added (No at step S 45 ), the system controller  51  displays the acquired still image data on the display screen as a preview (step S 46 ), and proceeds to step S 48 . 
     If the error information is added to the still image data (Yes at step S 45 ), the system controller  51  displays the acquired still image data together with the error information on the display device as a preview (step S 47 ), and proceeds to step S 48 . 
     The system controller  51  then stands by until the operating element for executing printing or accumulation is operated (No at step S 48 ). If the execution of printing or accumulation is instructed (Yes at step S 48 ), the system controller  51  executes the process of printing or accumulation by using the acquired still image data (step S 49 ), and terminates the present process. 
     An operation of the image forming apparatus  2  at the side that transmits still image data will now be described with reference to  FIG. 26 . Here,  FIG. 26  is a flowchart illustrating an example of a procedure of a still image data providing process. In the present process, still image data at the timing when the trigger operation is performed, is acquired. In the present process, if the still image data cannot be generated under the condition indicated by the acquisition request, substitute still image data is transmitted with the error information. 
     As a premise of the present process, it is assumed that the conference screen G 5  is displayed on the display device  31  and moving image data is exchanged (transmitted and received) with the other image forming apparatus  2  (step S 51 ). 
     The system controller  51  stands by until an acquisition request is received from the other image forming apparatus  2  (No at step S 52 ). Upon receiving the acquisition request (Yes at step S 52 ), the system controller  51  determines whether the moving image data at the timing indicated by the acquisition request (time information) is retained (step S 53 ). If it is determined that the moving image data is retained (Yes at step S 53 ), the system controller  51  extracts the still image data at the indicated timing from the retained moving image data (step S 54 ), and proceeds to step S 57 . 
     If it is determined that the moving image data is not retained (No at step S 53 ), the system controller  51  extracts still image data from the retained moving image data (step S 55 ). The system controller  51  then sets a first error flag (step S 56 ), and proceeds to step S 57 . 
     At the subsequent step S 57 , the system controller  51  executes a process of converting the still image data extracted at step S 54  or step S 55  to the resolution and the image size according to the image quality and the image size indicated by the acquisition request (image quality information and image size) (step S 57 ). The system controller  51  then determines whether the process at step S 57  has finished successfully (step S 58 ). If it is determined that it has finished successfully (Yes at step S 58 ), the system controller  51  proceeds to step S 61 . 
     If it is determined that the conversion process has failed (No at step S 58 ), the system controller  51  converts the still image data to the other resolution or the image size (step S 59 ). The system controller  51  then sets a second error flag (step S 60 ), and proceeds to step S 61 . The resolution or the image size to be converted at step S 59  is optional, as long as the conversion process finishes successfully. 
     The system controller  51  then determines whether an error flag (first error flag or second error flag) is set on the generated still image data (step S 61 ). If it is determined that the error flag is not set (No at step S 61 ), the system controller  51  transmits the generated still image data to the other image forming apparatus  2  of the request source (step S 62 ), and terminates the present process. 
     If it is determined that the error flag is set (Yes at step S 61 ), the system controller  51  adds error information according to the error flag to the generated still image data. The system controller  51  then transmits the still image data added with the error information to the other image forming apparatus  2  of the request source (step S 63 ), and terminates the present process. 
     As described above, according to the second characteristic of the image forming apparatus  2 , the image forming apparatus  2  of the reception side, which receives the distribution of moving image data, transmits an acquisition request for still image data to the image forming apparatus  2  of the distribution side, according to the instruction from the user. The image forming apparatus  2  of the distribution side generates still image data from the moving image data, which is picked up by the camera unit  20 , according to the acquisition request. The image forming apparatus  2  of the distribution side then provides the still image data to the image forming apparatus  2  of the reception side. Thus, the image forming apparatus  2  of the reception side can acquire the still image data having higher image quality from the moving image data being distributed from the image forming apparatus  2  of the distribution side. Consequently, it is possible to use the still image data having higher image quality for printing, saving, and the like in a suitable manner. 
     The image forming apparatus  2  of the reception side transmits the time information that indicates the timing of the moving image data displayed at the time of trigger operation, by including it in the acquisition request. Thus, it is possible to acquire the still image data at the timing. The image forming apparatus  2  of the reception side transmits the image quality information that indicates the image quality specified via the image quality specification buttons B 81  to B 84 , by including it in the acquisition request. Thus, it is possible to acquire the still image data having the indicated image quality. Furthermore, the image forming apparatus  2  of the reception side transmits the image size information indicating the image size specified via the size setting button B 71  by including it in the acquisition request. Thus, it is possible to acquire the still image data having the indicated image size. Consequently, it is possible to improve the convenience of the user who acquires the still image data. 
     If the still image data cannot be generated under the condition indicated by the acquisition request, the image forming apparatus  2  of the distribution side provides substitute still image data to the image forming apparatus  2  of the reception side, together with the error information. Thus, the image forming apparatus  2  of the reception side can print and save by using the substitute still image data. Hence, it is possible to improve the convenience of the user. 
     Second Embodiment 
     In the first embodiment, the configuration of the image forming apparatus  2  that can change the image pickup direction and the focus position of the camera unit  20  has been described. The image forming apparatus  2  described above is provided with a plurality of functions (applications) that use the camera unit  20  such as the copy function and presentation function. In such a case, the same setting value of the image pickup direction and the focus position of the camera unit  20  may be used for each application every time. However, it is troublesome for the user to reset the image pickup direction and the focus position of the camera unit  20 , every time the application is started. 
     The second embodiment describes a configuration in which the setting value of the image pickup direction and the focus position of the camera unit  20  can be saved for each application. The same constituent elements as those in the first embodiment are denoted by the same reference numerals and a detailed description thereof will be omitted. 
       FIG. 27  is a block diagram illustrating an example of a hardware configuration of an image forming apparatus  3  according to the second embodiment. As illustrated in  FIG. 27 , the image forming apparatus  3  includes a system controller  51   a . As the system controller  51  described above, the system controller  51   a  has a computer configuration including the CPU, the SoC, the ROM, the RAM, and the like. The system controller  51   a  integrally controls the operation of the image forming apparatus  3 . More specifically, the system controller  51   a  controls the image pickup direction and the focus position of the camera unit  20  according to the application being started. Because the functional configuration of the image forming apparatus  3  (system controller  51   a ) is the same as that of the image forming apparatus  2  (refer to  FIG. 6 ), the description thereof will be omitted. 
     Hereinafter, characteristic operations of the image forming apparatus  3  according to the present embodiment will be described. A setting operation that sets the image pickup direction and the focus position of the camera unit  20  for each application will now be described. 
     For example, upon receiving an operation of the initial setting button B 112  on the initial screen G 1  described above, the system controller  51   a  displays an application setting screen on the display device  31 , by collaborating with the UI controlling unit  103 . 
       FIG. 28  is a diagram illustrating an example of an application setting screen. As illustrated in  FIG. 28 , an application setting screen G 9  has operating elements for setting and saving the image pickup direction and the focus position of the camera unit  20 , for each application (function) installed in the image forming apparatus  3 , such as a copy and a scanner. 
     Here, an image pickup direction setting button B 91  is an operating element for setting the image pickup direction of the camera unit  20 . The user of the image forming apparatus  3  can specify (set) the image pickup direction of the camera unit  20 , by operating the image pickup direction setting button B 91 . A method for specifying the image pickup direction is optional. For example, the image pickup direction setting button B 91  may be operated to display a dedicated screen for specifying the image pickup direction, by displaying the image picked up by the camera unit  20  and the like. The image pickup direction setting button B 91  may also be operated to specify the image pickup direction, by displaying a plurality of directions such as the vertical direction, the horizontal direction, the front direction, the rear direction, and the like, as candidates. The user may manually change the image pickup direction of the camera unit  20  after operating the image pickup direction setting button B 91 , and acquire the image pickup direction after the change. 
     A focus position setting button B 92  is an operating element for setting the focus position of the camera unit  20 . The user of the image forming apparatus  3  can specify (set) the focus position of the camera unit  20 , by operating the focus position setting button B 92 . A method for specifying the focus position is optional. For example, the focus position setting button B 92  may be operated to display the focus position specification screen G 3  ( FIG. 12 ) and the like described above. The focus position setting button B 92  may also be operated to specify the focus position, by displaying a plurality of positions such as the upper side and the center, as candidates. It is also possible to display different document sizes as candidates. In this case, the focus position is identified from the specified document size, by using the focus position setting table T 1  ( FIG. 14 ) described above. 
     A save button B 93  is an operating element for saving the setting value of the camera unit  20 , set via the image pickup direction setting button B 91  and the focus position setting button B 92 . More specifically, upon receiving an operation of the save button B 93 , the system controller  51   a  saves (stores) the setting value (image pickup direction and focus position) of the camera unit  20 , which is set for the corresponding application, in the application setting information. 
     Here,  FIG. 29  is a schematic diagram illustrating an example of a data configuration of application setting information. As illustrated in  FIG. 29 , application setting information T 2  stores therein the setting values (image pickup direction and focus position) of the camera unit  20  for the application, for each application name that identifies the application, in an associated manner. For example, the application setting information T 2  is retained in the storage unit  57  and the like of the image forming apparatus  3 . Upon receiving an operation of the save button B 93 , the system controller  51   a  saves (updates) the setting value set via the image pickup direction setting button B 91  or the focus position setting button B 92 , by associating it with the application name of the corresponding application. 
     In the application setting information T 2 , the image pickup direction of “lower side” and the focus position of “(G, 4)” are set for the application names of “copy”, “FAX”, and “scanner” as an example. The image pickup direction of “front” and the focus position of “(D, 3)” are set for the application name of “observation” as an example. The image pickup direction of “rear” and the focus position of “(D, 3)” are set for the application name of “special copy” as an example. Here, the coordinates of the guide image described in  FIG. 10  are used to indicate the focus position. However, the description is not limited thereto. 
     In the application setting screen G 9  in  FIG. 28 , the image pickup direction and the focus position can be set for each application. However, it is not limited thereto, and it is also possible to set either of the two. In the application setting screen G 9  in  FIG. 28 , the setting value is saved according to the operation of the save button B 93 . However, it is not limited thereto, and the setting value set via the image pickup direction setting button B 91  and the focus position setting button B 92  may be directly saved in the application corresponding to the application setting information T 2 . It is preferable that the system controller  51   a  displays the current setting value saved in the application setting information T 2  on the image pickup direction setting button B 91  and the focus position setting button B 92 , upon displaying the application setting screen. 
       FIG. 30  is a flowchart illustrating an example of a procedure of an application setting process. The system controller  51   a  stands by until the initial setting button B 112  or the like is operated to instruct to display the application setting screen G 9  (No at step S 71 ). If it is instructed to display the application setting screen G 9  (Yes at step S 71 ), the system controller  51   a  displays the application setting screen G 9  on the display device  31  (step S 72 ). 
     The system controller  51   a  then determines whether the image pickup direction setting button B 91  is operated (step S 73 ). If the image pickup direction setting button B 91  is operated (Yes at step S 73 ), the system controller  51   a  temporarily stores the image pickup direction specified by the user as a setting value of the corresponding application (step S 74 ), and proceeds to step S 75 . If the image pickup direction setting button B 91  is not operated, the system controller  51   a  proceeds directly to step S 75 . 
     At step S 75 , the system controller  51   a  determines whether the focus position setting button B 92  is operated (step S 75 ). If the focus position setting button B 92  is operated (Yes at step S 75 ), the system controller  51   a  temporarily stores the focus position specified by the user as the setting value of the corresponding application (step S 76 ), and proceeds to step S 77 . If the focus position setting button B 92  is not operated, the system controller  51   a  proceeds directly to step S 77 . 
     At step S 77 , the system controller  51   a  determines whether the save button B 93  is operated (step S 77 ). If the save button B 93  is operated (Yes at step S 77 ), the system controller  51   a  saves the setting value temporarily stored for the corresponding application in the application setting information T 2  (step S 78 ), and proceeds to step S 79 . Here, if the setting value is not temporarily stored, an error indicating that the image pickup direction and the focus position are not yet set, may be displayed. If the save button B 93  is not operated, the system controller  51   a  proceeds directly to step S 79 . 
     At step S 79 , the system controller  51   a  determines whether the termination of the present process is instructed by the operation such as erasing the screen (step S 79 ). Here, if the termination of the present process is not instructed (No at step S 79 ), the system controller  51   a  returns to step S 73 . If the termination of the present process is instructed (Yes at step S 79 ), the system controller  51   a  erases the application setting screen G 9  (step S 80 ), and terminates the present process. 
     An operation for starting an application will now be described as a characteristic operation of the image forming apparatus  3  according to the present embodiment. 
     When the activation (startup) of an application is instructed by the application startup operation, the system controller  51   a  changes the image pickup direction and the focus position of the camera unit  20 , based on the setting value set for the application. More specifically, the system controller  51   a  reads out the setting value of the camera unit  20  corresponding to the application to be activated, from the application setting information T 2 , and changes the image pickup direction and the focus position of the camera unit  20  based on the setting value. With regard to the application for which there is no setting value in the application setting information T 2 , a default setting value (default value) determined in advance will be used. 
       FIG. 31  is a flowchart illustrating an example of a procedure of an application startup process. The present process corresponds to steps S 18  and S 19  in the operation receiving process described in the first embodiment. 
     The system controller  51   a  stands by until an application startup operation for activating the application is operated (No at step S 91 ). Upon receiving the application startup operation (Yes at step S 91 ), the system controller  51   a  starts the application to be activated (step S 92 ). 
     The system controller  51   a  then determines whether the setting value of the camera unit  20  corresponding to the application started at step S 92  is saved in the application setting information T 2  (step S 93 ). If it is determined that the setting value is being saved (Yes at step S 93 ), the system controller  51   a  changes the image pickup direction and the focus position of the camera unit  20  based on the setting value (step S 94 ), and terminates the present process. 
     At step S 93 , if it is determined that the setting value is not being saved (No at step S 93 ), the system controller  51   a  changes the image pickup direction and the focus position of the camera unit  20  based on the default value (step S 95 ), and terminates the present process. This does not apply to the application that does not use the camera unit  20 . 
     As described above, the image forming apparatus  3  according to the present embodiment saves the setting value of the camera unit  20  for each application, and when the application is started, changes the image pickup direction and the focus position of the camera unit  20 , based on the setting value corresponding to the application. Thus, the image pickup direction and the focus position of the camera unit  20  can be changed automatically for each application. Consequently, it is possible to improve the convenience of the user. 
     The number of pieces of the application setting information T 2  is not limited to one, and may be prepared for each user. In this case, the setting value of each application set by the login user is saved in the application setting information T 2  for the user. Consequently, the image pickup direction and the focus position of the camera unit  20  set by each user can be reflected, when each application is started. Thus, it is possible to further improve the convenience of the user. 
     For example, in the embodiment described above, the present invention is applied to the image forming apparatus  2 . However, it is not limited thereto. More specifically, the second characteristic of the image forming apparatus  2  may be applied to an information processing device such as a PC or a smartphone that has a communication function and a display function. 
     In the embodiment described above, image data is exchanged in both directions. However, it is not limited thereto. It is also possible to transmit image data only from the device of the transmission side that supplies still image data. In the embodiment described above, the camera unit  20  is also installed in the device of the reception side that receives still image data. However, it is not limited thereto, and the camera unit  20  may be omitted. 
     In the present embodiment, the moving image data picked up by the camera unit  20  is distributed live (live streaming). However, it is not limited thereto, and the moving image data stored in the storage unit  57  and the like may be distributed on demand. 
     The present invention exhibits the advantageous effect of being able to acquire still image data with higher image quality from moving image data being distributed. 
     Although the invention has been described with respect to specific embodiments for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.