Patent Publication Number: US-9900568-B2

Title: Remote communication system, method for controlling remote communication system, and storage medium

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present disclosure relates to a remote communication system used to communicate with a remote site, a method for controlling the remote communication system, and a storage medium. 
     Description of the Related Art 
     Systems used to communicate with a communication partner located at a different place (a remote site) have been developed. For example, Japanese Patent Laid-Open No. 2008-191613 describes a remote conference system used to conduct a conference with a person located at a different place. The system described in Japanese Patent Laid-Open No. 2008-191613 includes a camera for capturing the image of a person, a projector for projecting an image, and a screen that displays the image projected by the projector. 
     According to the system described in Japanese Patent Laid-Open No. 2008-191613, the image of a person captured by a camera set in a conference room is projected onto a screen by a projector set at the other party&#39;s location (a remote site). In addition, the image of a person captured by a camera set at the other party&#39;s location is projected onto a screen by a projector in the conference room. Furthermore, according to the system described in Japanese Patent Laid-Open No. 2008-191613, by displaying a real-size image of a person, the realistic sensation of actually being in a conference room can be increased. 
     When several people physically located in the same space (e.g., the same room) simply communicate with one another, the people are generally standing and face one another at a distance of 1 to 2 m. If such a form of communication or a similar form of communication can be applied to communication with people in a remote site, the people can easily communicate with one another and understand one another. 
     As described in Japanese Patent Laid-Open No. 2008-191613, the real-size image of a person in a remote site can be displayed. However, if the person who is standing communicates with another person, the person may move during the communication. At that time, if the person moves in the right-left direction, the projected image does not cause a significant trouble. However, if the person moves in the front-rear direction of the screen, a problem of the projected image arises, since the size of the captured image of the person varies due to a change in the distance between the camera and the person. Frequent changes in the size of the person projected onto a screen increase unpleasantness of a person and, thus, the realistic sensation is reduced. 
     To display the real-size image of a person, the size of the image can be manually changed. However, it is troublesome to send an instruction to change the display size each time the person moves in the front-rear direction and, thus, it is difficult to have a smooth communication. 
     SUMMARY OF THE INVENTION 
     The present disclosure provides a scheme that allows smooth communication with a person at a remote site without giving unpleasantness caused by a significant change in the size of the projected image of the person. 
     According to an aspect of the present disclosure, a remote communication system includes a first projector configured to project one or more images transmitted from a remote site onto a first projection plane; at least one image capturing unit disposed on the first projection plane, the at least one image capturing unit operating to capture an image; an extraction unit configured to extract a person part image from the image captured by the at least one image capturing unit, a scaling unit configured to scale the image captured by the at least one image capturing unit in accordance with a distance from the at least one image capturing unit to a person serving as a subject, and a second projector configured to project, onto a second projection plane disposed at or in the remote site, the image, which is subject to the extraction by the extraction unit and which is scaled by the scaling unit. 
     According to other aspects of the present disclosure, one or more additional remote communication systems, one or more remote communication apparatuses, one or more control methods and one or more storage mediums are discussed herein. Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A to 1C  are cross-sectional views of a remote communication system according to an exemplary embodiment of the present disclosure. 
         FIG. 2  is an external view of the remote communication system according to the exemplary embodiment of the present disclosure. 
         FIG. 3  is a hardware configuration diagram of the remote communication system according to the exemplary embodiment of the present disclosure. 
         FIG. 4  illustrates the image capturing area of a front camera according to the exemplary embodiment of the present disclosure. 
         FIGS. 5A to 5F  illustrate a scaling process and a trimming process according to the exemplary embodiment of the present disclosure. 
         FIG. 6  is a flowchart of a process to capture the image of a person according to the exemplary embodiment of the present disclosure. 
         FIG. 7  is a flowchart of the process to capture the image of a person according to the exemplary embodiment of the present disclosure. 
         FIG. 8  is a flowchart of a process to project an image according to the exemplary embodiment of the present disclosure. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     An exemplary embodiment of the present disclosure is described in detail below with reference to the accompanying drawings. The following description of the exemplary embodiment is merely illustrative in nature and is in no way intended to limit the disclosure and/or invention defined by the claims. All of the features and the combinations thereof described in the embodiment are not necessarily essential to the disclosure. 
       FIGS. 1A to 1C  are cross-sectional views of a remote communication system according to the present disclosure. By using the remote communication system, communication can be performed between an office 1 disposed in a headquarter and an office 2 disposed on a blanch A or between the office 1 and an office 3 disposed in a branch B. Note that while the description is given with reference to three offices as an example, communication may be performed only between two offices, that is, the office 1 and the office 2. In addition, all the offices may be referred to as a “remote communication system”. Alternatively, only the configuration included in a single office may be referred to as a “remote communication system”. 
     In addition, the offices described herein may be separated so that the time required to move from one of the offices to the other is several hours, or the offices may be different conference rooms in the same building. That is, the term “remote” refers to physically different spaces and does not define the physical distance and the time length required for movement from one place to another place. 
     The office 1 illustrated in  FIG. 1A  includes a projector  101 , a background camera  102 , a screen  103 , front cameras  104 , and a back camera  105 . The projector  101  is a projection device that projects the image captured in one of the other offices onto the screen  103 . The screen  103  serves as a projection plane that displays the image projected by the projector  101 . Note that the screen  103  may be a screen temporarily placed when communication is performed with one of the other offices. Alternatively, a wall of the office may serve as the screen  103 . In addition, while the present exemplary embodiment is described with reference to an example in which the projector and the screen are used to display an image, the image may be displayed using a large liquid crystal display. 
     The front cameras  104  are front image capturing devices disposed in front of a person  106  to capture the images of the person  106 . In this example, to capture the image of the whole body of the person  106 , three front cameras  140 , that is, front cameras  104   a ,  104   b , and  104   c  are employed. However, at least one front camera can be employed. The process related to capturing the image of the person  106  using the front cameras  104  is described in more detail below. 
     The background camera  102  is a background image capturing device that captures the background image of the person  106  (i.e., the image taken in the right direction in  FIG. 1A ). In this example, the office 1 is not a room dedicated to remote communication, but is an ordinary office room for everyday business. The background image captured by the background camera  102  contains the images of desks, chairs, and cabinets of employees and the image of a person who is conducting another business transaction. By projecting such a background image together with the image of the person captured by the front cameras  104 , a simulated environment as if people stood and chatted with one another in the corner of the office room can be produced. Note that to prevent the background image (an object) from being hidden by the image of the person  106 , it is desirable that the background camera  102  be mounted on the upper section of the room in the vertical direction (near the ceiling). 
     The back camera  105  is a back image capturing device for capturing the image of the person  106  or the image displayed on the screen  103  in the direction from the right to the left in  FIG. 1A . Since the person  106  faces to the screen  103  (i.e., the left in  FIG. 1A ) during remote communication, the back camera  105  captures the image of the person  106  from behind. Note that the distance between the back camera  105  and the person  106  is longer than the distance between the front camera  104  and the person  106 . Accordingly, the back camera  105  can capture the image of the entire body of the person  106 . 
     The front camera  104  includes a range sensor for detecting the distance from the front camera  104  to the subject. The image captured by the front camera  104  includes an RGB color image with 8 bits per channel and 3 channels and a range image with 8 bits per channel and 1 channel. In contrast, each of the background camera  102  and the back camera  105  does not include a range sensor. Accordingly, an image captured by each of the background camera  102  and the back camera  105  includes an RGB color image with 8 bits per channel and 3 channels, but does not include a range image. Note that the images captured by each of the front camera  104 , the background camera  102 , and the back camera  105  are time-series still images, which are sequentially projected in a remote site. In this manner, the images are played back in the form of a moving image. 
     Like the office 1, in the office 2 in which a person  116  is located ( FIG. 1B ), equipment similar to that in the office 1 (i.e., a projector  111 , a background camera  112 , a screen  113 , a front camera  114 , and a back camera  115 ) is provided. In addition, in the office 3 in which a person  126  is located ( FIG. 1C ), equipment similar to that in the office 1 or 2 (i.e., a projector  121 , a background camera  122 , a screen  123 , a front camera  124 , and a back camera  125 ) is provided. Note that each of the screens  103  and  113  measures 2.3 meters high by 4 meters wide. In contrast, the screen  123  has a relatively smaller size and measures 1 meter high by 2 meters wide. When communication using a real-size projected image of the entire body is desirable, the offices 1 and 2 each having a large screen need to be used. However, if the space is limited, a small screen can be used as in the office 3. At that time, the image of the entire body of a person located in the remote site cannot be displayed on the screen  123 . Thus, for example, the image of only the upper body of the person is projected on the screen  123 . 
       FIG. 2  is an external view of the remote communication system viewed in a direction from the right to the left in  FIG. 1A . In  FIG. 2 , the person  106  located in the office 1 is communicating with the person  116  located in the office 2. Since as described above, the screen  103  is horizontally long, two projectors  101  (i.e., projectors  101   a  and  101   b ) are provided. However, a single projector may project the image. The background camera  102  is set in the upper middle of the screen  103 . The front cameras  104   a ,  104   b , and  104   c  are embedded in the screen  103  so as to be arranged in a line in the middle section of the screen  103  in the vertical direction. 
     A digitizer  201  is a detecting device that detects the operation performed on the screen  103  by a user. The digitizer  201  includes a transmitter  201   a  and a receiver  201   b . If an infrared light beam projected by the transmitter  201   a  is blocked by, for example, part of the body of the person  106  or a pointer held by the person  106 , the digitizer  201  outputs the coordinates of the position. Note that in this example, the transmitter  201   a  and the receiver  201   b  are disposed at the left and right ends of the screen  103 , respectively. However, the transmitter  201   a  and the receiver  201   b  may be disposed at the upper and lower ends of the screen  103 , respectively. In addition, a technique for detecting the operation performed by a user is not limited to a technique using a digitizer. For example, the screen  103  may have a touch panel function, and a position in the screen  103  at which the screen  103  is pressed may be detected. 
     The image of the person  116  captured by the front camera  114  set in the office 2 is projected onto the screen  103 . In addition, in  FIG. 2 , a document (e.g., a conference material) stored in a document management server  340  (described below) is displayed as the background image of the person  116 . It can be switched whether as the background of the person  116 , a document stored in the document management server  340  is projected or the background image of the office 2 captured by the background camera  112  is projected in accordance with the operation performed by the person  116  and detected by the digitizer  201 . 
       FIG. 3  is a hardware configuration diagram of the remote communication system. A central processing unit (CPU)  316  included in a control apparatus  310  reads out a control program stored in a read only memory (ROM)  318  and controls the equipment provided in the office 1. A random access memory (RAM)  317  is used as temporary memory areas, such as a main memory and a work area of the CPU  316 . Note that in the office 1, the CPU  316  uses a single memory (the RAM  317 ) and performs processes indicated by a flowchart described below. However, another form of processing can be employed. For example, a control apparatus  310  may be provided for each of the cameras, projectors, and digitizer. Thus, the processes may be performed by a plurality of CPUs and RAMs (or hard disk drives (HDDs) or solid state drives (SSDs)) that are in cooperation with one another. Alternatively, some of the processes described below may be performed by a hardware circuit, such as an application specific integrated circuit (ASIC). 
     The offices are connected to one another using a network  300 . Any network selected from among a wired network, a wireless network, a wide area network (WAN), a local area network (LAN), a public line, and a dedicated line can be employed as the network  300  in accordance with the environment. To connect the office 1 to the network  300 , a network interface (I/F)  311  is employed. 
     Each of the offices has a microphone and a speaker disposed therein (not illustrated in  FIGS. 1A to 1C  and  FIG. 2 ). The speech emanated from a person in the office is converted into an audio signal by a microphone and is output from a speaker in a remote site. The office 1 has a microphone  319  and a speaker  320  disposed therein. To control the input of speech using the microphone  319  and the output of the speech using the speaker  320 , an audio I/F  312  is employed. 
     To control projection of an image using the projector  101 , a projector I/F  313  is employed. To control detection of the operation performed by a user using the digitizer  201 , a digitizer I/F  314  is employed. To control the image capturing operations performed by the front camera  104 , the back camera  105 , and the background camera  102 , a camera I/F  315  is employed. 
     Note that each of the offices 2 and 3 has a configuration that is the same as that of the office 1 (not illustrated). Examples of the above-mentioned interfaces include a universal serial bus (USB), a high definition multimedia interface (HDMI (trade name)), a wired LAN, and a wireless LAN, one of which is selected as needed. 
     When an image captured in each of the offices and speech input in an office are sent to the other offices, a relay server  350  relays the image and speech. The document management server  340  stores documents to be projected onto the screen by the projector in each of the offices (e.g., a conference material). As illustrated in  FIG. 2 , upon receiving an instruction to project a document together with the image of the person, the CPU  316  acquires the document from the document management server  340  and causes the projector  101  to project the document. Note that the instruction to project the document can be output from any one of the offices that perform remote communication. 
     When the screen  103  is used as an operation unit of the remote communication system, an object management server  330  stores objects to be projected onto the screen  103  by the projector  101 . An example of the object is an operation button used to select one of the offices to be connected. If the remote communication system is started in the office 1, the CPU  316  acquires, from the object management server  330 , selection buttons each corresponding to one of the offices and causes the projector  101  to project the selection buttons onto the screen  103 . If the person  106  touches the screen  103 , the digitizer  201  detects the coordinates of the touched position, and the CPU  316  identifies one of the selection buttons corresponding to the detected coordinates. Thereafter, the CPU  316  starts remote communication with the office corresponding to the identified selection button. 
       FIG. 4  illustrates the image capturing areas of the front cameras  104 . The front cameras  104   a ,  104   b , and  104   c  are set at heights of a (1750 mm), b (1050 mm), and c (350 mm) from the floor, respectively. 
     The angles of view of the front cameras  104   a ,  104   b , and  104   c  in the vertical direction are θa, θb, and θc, respectively. In this example, θa, θb, and θc are the same. A distance d from the front camera  104  to the person  106  is calculated on the basis of the range image captured by the front camera  104 . In  FIG. 4 , the positions  106   a  and  106   b  of the person  106  indicate that the person  106  is moving toward the screen  103  in the front-rear direction. A distances d1 is the distance from the person  106  standing at the position of the person  106   a  to the front camera  104  (the screen  103 ), and a distances d2 is the distance from the person  106  standing at the position  106   b  to the front camera  104  (the screen  103 ). Note that the position  106   a  is the closest position to the screen  103  at which the entire body of the person  106  can be captured by the front camera  104 . If the person  106  further moves closer to the screen  103 , the person  106  is outside the angle of view of the front camera  104  and, thus, part of the image of the body of the person  106  disappears. 
     Scaling and trimming of the image captured by the front camera  104  is described next with reference to  FIGS. 5A to 5F . According to the present exemplary embodiment, the position  106   a  at which the person  106  is standing is considered as a reference position. Even when the person  106  slightly moves back from the reference position, the image of the person  106  is projected so as to be displayed with the same image size as when the person  106  is located at the position  106   a . Note that if the position  106   b  is away from the screen  103  by 2 meters or more, a process described below with reference to  FIG. 7  is performed. Thus, the image of the person  106  is not projected. 
     If the person  106  stands at the position  106   b , the size of the person in the images captured by each of the front cameras  104   a ,  104   b , and  104   c  is smaller than that when the person  106  stands at the position  106   a . In contrast, if the person  106  stands at the position  106   a , the images captured by the front cameras  104   a ,  104   b , and  104   c  do not overlap one another. However, if the person  106  stands at the position  106   b , overlapping portions of the images appear. 
     According to the present exemplary embodiment, by taking into account the above description, a scaling process and a trimming process are performed. The scaling process is described first.  FIGS. 5A, 5B, and 5C  illustrate the images captured by the front cameras  104   a ,  104   b , and  104   c  when the person  106  stands at the position  106   b , respectively. A scaling process is performed on the images using a scaling factor based on the distances d1 and d2. More specifically, the images illustrated in  FIGS. 5A, 5B , and  5 C are scaled (enlarged) by a value obtained by dividing the distance d2 by the distance d1. The images obtained as the result of the scaling process are illustrated in  FIGS. 5D, 5E, and 5F . 
     The trimming process is described next. The central points of the images illustrated in  FIGS. 5D, 5E , and  5 F are considered as the reference points. An area of each of the images corresponding to the size of the image before the scaling process (a rectangular area enclosed by a dotted line in each of  FIGS. 5D, 5E, and 5F ) is maintained, and the other area is removed. In this manner, the overlapping areas among the images can be removed. The resultant images are sequentially combined and, thus, the image of the person can be obtained. At that time, the size of the combined image is the same as the size of the image of the person  106  captured when the person  106  is located at the position  106   a , and the combined image of the person does not have any overlapping portion. 
       FIGS. 6 and 7  are flowcharts illustrating a process to capture the images of the person  106  using the front cameras  104  and a process to combine the images of the person captured by the front cameras  104 . Each of operations (steps) indicated by the flowcharts in  FIGS. 6 and 7  is realized by the CPU  316  that is disposed in the office 1 and that executes a control program stored in the ROM  318 . 
     In step S 601 , the value of a variable N is initialized to 1. In step S 602 , among the front cameras  104   a ,  104   b , and  104   c , the CPU  316  instructs the front camera  104  corresponding to the variable N to capture the image of the person  106 . In step S 603 , the image of only the person  106  is generated from the image captured by the front camera  104 . 
       FIG. 7  is a flowchart illustrating the process performed in step S 603  in detail. In step S 701 , a range image included in the captured image obtained in step S 602  is binarized. According to the present exemplary embodiment, the person  106  stands at a position in the range from the position away from the screen  103  (the front camera  104 ) by 1 meter to the position away from the screen  103  by 2 meters. Accordingly, a minimum value of the distance from the front camera  104  to the subject is set to 1 meter, and the maximum value of the distance is set to 2 meters. In this manner, a predetermined range is set. In addition, for each of the pixels of the range image, the value of the pixel is changed to 255 if the value is within the predetermined range. The values of the other pixels are set to 0. 
     In step S 702 , an erosion process that replaces the value of the pixel of interest with 0 under the condition that at least one pixel in the neighborhood is 0 or a dilation process that replaces the value of the pixel of interest with 255 under the condition that at least one pixel in the neighborhood is 255 is performed. In this manner, isolated point noise can be removed. In step S 703 , a smoothing filter process (e.g., a Gaussian filter process) is performed to smooth the outline of an area where pixels each having a value of 255 are continuously arranged. 
     In step S 704 , a mask process is performed. Thus, a pixel of the color image corresponding to a pixel of the range image having a value of 255 is made non-transparent, and a pixel of the color image corresponding to a pixel of the range image having a value of 0 is made fully transparent (is transparentized). Through the process, the image of a person part is extracted from the image captured by the front camera  104 . As used herein, the term “person part” refers to not only the image of a person but the image of the person and, for example, a pointer or a product sample held by the person. 
     In step S 705 , as illustrated in  FIGS. 5A to 5F , the scaling process is performed on the images of the person illustrated in  FIGS. 5A, 5B, and 5C  to generate the images of the person illustrated in  FIGS. 5D, 5E, and 5F , respectively. In addition, in step S 706 , as illustrated in  FIGS. 5A to 5F , the trimming process is performed on the images of the person illustrated in  FIGS. 5D, 5E, and 5F . 
     Referring back to  FIG. 6 , in step S 604 , it is determined whether the value of the variable N is less than the number of the front cameras  104  (3 according to the present exemplary embodiment). If the value of the variable N is less than the number of the front cameras  104 , the processing proceeds to step S 705 , where a value of 1 is added to the variable N. Thereafter, the processing returns to step S 601 . However, if the value of the variable N is not less than the number of the front cameras  104  (the value of the variable N is equal to the number of the front cameras  104 ), the processing proceeds to step S 606 . 
     In step S 606 , the images of the person subjected to the process performed in step S 603  are combined. In addition, since after the combining process, a blank (a space above the head, a space on the left of the right hand, a space on the right of the left hand, and a space under the feet) is left in the combined image, the trimming process is performed on a rectangular area including the pixels each having a value of 255. 
     In step S 607 , the image obtained through the process performed in step S 606  is transmitted to the office 2 that is connected to the office 1. In step S 608 , it is determined whether an instruction to complete the remote communication is received. If an instruction to complete the remote communication is received, the processing is completed. However, if an instruction to complete the remote communication is not received, the processing returns to step S 601 . Thereafter, the processes in step S 601  and the subsequent steps are performed again. 
     Note that in this example, the processes in steps S 603  and S 606  are performed on the image capturing side (the office in which a person representing the subject is located). However, the processes may be performed in the office on the projection side (the office in which the captured image is projected). In addition, the extraction process of the person part described in steps S 701  to S 704  may be performed after the combining process described in step S 606 . Furthermore, although description is not given in this example, the image captured by the background camera  102  and the image captured by the back camera  105  are transmitted to the office 2 that is connected to the office 1, synchronously or asynchronously with the transmission of the image performed in step S 607 . 
       FIG. 8  is a flowchart of a process to project the image transmitted from an office connected to the office. Each of operations (steps) illustrated in  FIG. 8  is realized by the CPU  316  that is disposed in the office 1 and that executes a control program stored in the ROM  318 . Note that in this example, the processes described with reference to  FIGS. 6 and 7  are performed in the office 2 by, for example, the CPU provided in the office 2 in the same manner, and the resultant images transmitted from the office 2 are projected in the office 1. 
     In step S 801 , the front image of a person captured by the front camera  114  is received. In step S 802 , the back image of the person captured by the back camera  115  is received. In step S 803 , the background image captured by the background camera  112  is received. 
     In step S 804 , it is determined whether an instruction to display the front image of the person is received or an instruction to display the back image of the person is received. The instructions are received in accordance with the operation performed by the person  106  and detected by the digitizer  201 . If it is determined that an instruction to display the front image of the person is received, the processing proceeds to step S 805 , where the front image of the person received in step S 801  and the background image received in step S 803  are projected onto the screen  103 . However, if it is determined that an instruction to display the back image of the person is received, the processing proceeds to step S 806 , where the back image of the person received in step S 802  is projected onto the screen  103 . 
     In step S 807 , it is determined whether an instruction to complete the remote communication is received. If it is determined that an instruction to complete the remote communication is received, the processing is completed. However, if it is determined that an instruction to complete the remote communication is not received, the processing returns to step S 801 . Thereafter, the processes in step S 801  and the subsequent steps are performed again. Note that the processes in the flowchart illustrated in  FIG. 6  and the processes in the flowchart illustrated in  FIG. 8  are continuously and concurrently performed during remote communication. 
     As described above, the remote communication system according to the present exemplary embodiment includes the projector  101  that projects, onto the screen  103 , the image transmitted from the office 2 located in a remote site. In addition, the screen  103  has a plurality of the front cameras  104  disposed therein. The CPU  316  performs an extraction process that extracts a person part from each of the images captured by the front cameras  104  (refer to step S 703 ) and a combining process that combines the plurality of images captured by the front cameras  104  (refer to step S 706 ). Furthermore, the remote communication system includes the projector  111  that projects, onto the screen  113  disposed in the office 2, the image subjected to the extraction process and the combining process. 
     By having such a configuration, communication can be smoothly performed with a remote site without providing unpleasantness caused by a significant change in the size of the projected image of a person. 
     Other Exemplary Embodiment 
     In addition, the present disclosure can be realized by performing the following processes. That is, the processes are providing a storage medium including software program code that realizes the functions of the above-described exemplary embodiment to a system or an apparatus and reading out the program code stored in the storage medium using a computer (a CPU or an MPU) in the system or the apparatus. 
     In such a case, the program code itself read from the storage medium realizes the functions of the above-described exemplary embodiment and, thus, the program code and the storage medium storing the program code constitutes at least one embodiment of the present disclosure. 
     Embodiment(s) of the present disclosure can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2015-095888 filed May 8, 2015, which is hereby incorporated by reference herein in its entirety.