Patent Publication Number: US-10326945-B2

Title: Image-taking apparatus, information processing apparatus, and image-taking system

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present disclosure is a continuation of U.S. patent application Ser. No. 14/534,503, filed Nov. 6, 2014, which claims the benefit of Japanese Priority Patent Application JP 2013-237716 filed Nov. 18, 2013, the entire contents of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present technology relates to an image-taking apparatus, an information processing apparatus, an image-taking system, and a program. 
     In recent years, products called lens-style cameras have been developed. A lens-style camera alone functions as a digital camera. Moreover, a lens-style camera is used in combination with a smartphone. As a result, a user experiences a new flavor of camera (for example see http://www.sony.jp/cyber-shot/qx/). 
     SUMMARY 
     Both lens-style cameras and smartphones have various functions necessary to take images. It is desirable to further increase the function of a system, in which a lens-style camera is in combination with a smartphone. 
     It is desirable to provide an image-taking apparatus, an information processing apparatus, an image-taking system, and a program capable of improving an exposure-control function out of image-taking functions. 
     According to an embodiment of this technology, an image-taking apparatus includes: a detector configured to detect brightness of an object image, and to output internal brightness information; and a controller configured to control exposure based on an exposure value, the exposure value being based on the internal brightness information and external brightness information received from an external apparatus. 
     According to the embodiment of this technology, the image-taking apparatus controls exposure based on an exposure value, the exposure value being based on brightness information input from outside. As a result, it is possible to control exposure more accurately. 
     According to an embodiment of this technology, the image-taking apparatus may further include a setting unit configured to select one of a first exposure value and a second exposure value to be used, the first exposure value being based on the internal brightness information, the second exposure value being based on both of the internal brightness information and the external brightness information. The controller may be configured to control exposure based on one of the first exposure value and the second exposure value selected by the setting unit. 
     According to the image-taking apparatus of the embodiment of this technology, a user is capable of selecting exposure control based on an exposure value, the exposure value being based on brightness information input from outside. 
     According to the image-taking apparatus of the embodiment of this technology, it is possible for a user to select exposure control based on an exposure value from outside, the exposure value being based on brightness information input from outside. 
     According to the image-taking apparatus of the embodiment of this technology, the image-taking apparatus may further include an output unit configured to output an image to the external apparatus, the image being taken with exposure controlled by the controller. 
     According to the image-taking apparatus of the embodiment of this technology, it is possible for a user to confirm an image from outside, exposure of the image being controlled based on an exposure value, the exposure value being based on brightness information input from outside. 
     According to an embodiment of this technology, the controller may be configured to control exposure based on a first exposure value if the external apparatus does not exist and based on a second exposure value if the external apparatus exists, the first exposure value being based on the internal brightness information, the second exposure value being based on both of the internal brightness information and the external brightness information. 
     According to an embodiment of this technology, the image-taking apparatus may further include a wireless receiver configured to receive the external brightness information. 
     According to an embodiment of this technology, the controller may be configured to correct the internal brightness information based on the external brightness information to thereby obtain the exposure value. 
     According to an embodiment of this technology, the image-taking apparatus may be capable of being fixed to the information processing apparatus. 
     According to an embodiment of this technology, an information processing apparatus includes: a detector configured to detect brightness of an object image; a determining unit configured to determine if an external image-taking apparatus exists or not; and an output unit configured to output the brightness information to the image-taking apparatus if the image-taking apparatus exists. 
     According to the information processing apparatus of the embodiment of this technology, brightness information is output to outside. The information processing apparatus is capable of causing an outside apparatus to control exposure based on an exposure value, the exposure value being at least based on the brightness information. As a result, it is possible to control exposure more accurately. 
     According to the information processing apparatus of the embodiment of this technology, the information processing apparatus may further include a receiver configured to receive an image sent from the image-taking apparatus. 
     According to the information processing apparatus of the embodiment of this technology, a user is capable of instructing to output brightness information to the outside, and instructing an outside apparatus to control exposure based on an exposure value, the exposure value being at least based on the brightness information. 
     According to the information processing apparatus of the embodiment of this technology, a user is capable of instructing to output brightness information to the outside, and instructing an outside apparatus to control exposure based on an exposure value, the exposure value being at least based on the brightness information. 
     According to the information processing apparatus of the embodiment of this technology, it is possible to automatically determine that brightness information is to be output to the outside, and automatically determine that an outside apparatus controls exposure based on an exposure value, the exposure value being at least based on the brightness information. 
     According to an embodiment of this technology, the information processing apparatus may further include a controller configured to display an image received by the receiver on a display unit. 
     According to the information processing apparatus of the embodiment of this technology, the information processing apparatus may further include an image-taking unit configured to take an object image. The controller may be configured to display an image obtained by the image-taking unit and an image received by the receiver on the display unit at the same time. 
     According to the information processing apparatus of the embodiment of this technology, it is possible for a user to confirm an image taken by using the information processing apparatus. 
     According to the information processing apparatus of the embodiment of this technology, it is possible to control exposure more accurately or just as a user intended. 
     According to the information processing apparatus of the embodiment of this technology, the output unit may be configured to output the brightness information wirelessly. 
     According to an embodiment of this technology, an image-taking system includes an information processing apparatus and an image-taking apparatus. 
     The information processing apparatus includes a detector configured to detect brightness of an object image, and to output external brightness information, a determining unit configured to determine if an external image-taking apparatus exists or not, and an output unit configured to output the external brightness information to the image-taking apparatus if the image-taking apparatus exists. The image-taking apparatus includes a detector configured to detect brightness of an object image, and to output internal brightness information, and a controller configured to control exposure based on an exposure value, the exposure value being based on the internal brightness information detected by the detector and external brightness information received from an external apparatus. 
     According to the image-taking system of the embodiment of this technology, the image-taking apparatus controls exposure based on an exposure value, the exposure value being based on brightness information input from the information processing apparatus. As a result, it is possible to control exposure more accurately. 
     According to the embodiment of this technology, brightness information is output to the image-taking apparatus. The information processing apparatus is capable of causing the image-taking apparatus to control exposure based on an exposure value, the exposure value being at least based on the brightness information. As a result, it is possible to control exposure more accurately. 
     As described above, according to this technology, it is possible to control exposure more accurately. 
     These and other objects, features and advantages of the present disclosure will become more apparent in light of the following detailed description of best mode embodiments thereof, as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view showing an image-taking apparatus of an embodiment of this technology; 
         FIG. 2  is a side view showing the image-taking apparatus of  FIG. 1 ; 
         FIG. 3  is a diagram showing an external structure of the image-taking apparatus of the embodiment of this technology attached to the information processing apparatus; 
         FIG. 4  is a diagram showing another external structure of the image-taking apparatus of the embodiment of this technology attached to the information processing apparatus; 
         FIG. 5  is a diagram showing another external structure of the image-taking apparatus of the embodiment of this technology attached to the information processing apparatus; 
         FIG. 6  is a block diagram showing the configuration of the image-taking apparatus and the configuration of the information processing apparatus of the embodiment of this technology; 
         FIG. 7  is a flowchart showing behaviors of the image-taking apparatus of the embodiment of this technology; 
         FIG. 8  is a flowchart showing the behavior of the information processing apparatus of the embodiment of this technology; 
         FIG. 9  is a diagram illustrating effects of the system of the embodiment of this technology; 
         FIG. 10  is another diagram illustrating effects of the system; 
         FIG. 11  is a flowchart showing behaviors of the image-taking apparatus according to another embodiment of this technology; 
         FIG. 12  is a diagram showing an example of the structure of the image-taking apparatus of the embodiment of  FIG. 11 ; 
         FIG. 13  is a diagram showing another example of the structure of the image-taking apparatus of the embodiment of  FIG. 11 ; 
         FIG. 14  is a flowchart showing behaviors of the information processing apparatus according to another embodiment of this technology; 
         FIG. 15  is a diagram illustrating the behaviors of the embodiment of  FIG. 14 ; 
         FIG. 16  is a first diagram showing a display window displayed on a display unit, which is a user interface of the information processing apparatus of this technology; 
         FIG. 17  is a second diagram showing the display window displayed on the display unit, which is a user interface of the information processing apparatus of this technology; and 
         FIG. 18  is a diagram showing another display window displayed on a display unit, which is a user interface of the information processing apparatus of this technology. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, embodiments of the present technology will be described with reference to the drawings. 
     [Example of External Structure of Image-Taking Apparatus] 
     Each of  FIG. 1  and  FIG. 2  is a diagram showing the external structure of an image-taking apparatus  100  of an embodiment.  FIG. 1  is a front view showing the image-taking apparatus  100 .  FIG. 2  is a side view showing the image-taking apparatus  100  (side view of image-taking apparatus  100  seen in direction A). 
     Moreover, in the example of this embodiment, the image-taking apparatus  100  is a cylindrical (columnar) image-taking apparatus. In other words, in this example, the shape of the image-taking apparatus  100  is similar to the shape of a lens unit alone of a general image-taking apparatus (for example, retractable lens type digital still camera). Note that the image-taking apparatus  100  includes operation members such as a zoom lever and a shutter key. However,  FIG. 1  and the like do not show them. Specifically, the image-taking apparatus  100  according to the embodiment of this technology includes no display unit such as a liquid-crystal panel configured to display stored images and obtained image. 
     The image-taking apparatus  100  includes a lens tube  160  and attachment tools  181  and  182 . The lens tube  160  accommodates the members of an optical system, an image-taking system, and the like. 
     The attachment tools  181  and  182  are attachments, and are used when the image-taking apparatus  100  is attached to an information processing apparatus  200  as shown in  FIG. 3  to  FIG. 5 . For example, the attachment tool  181  is moved in the direction  173  and the attachment tool  182  is moved in the direction  174  depending on the shape and the size of the information processing apparatus  200 . As a result, the attachment tools  181  and  182  fix the image-taking apparatus  100  on the information processing apparatus  200 . Moreover, an attached surface  175  (surface opposite to surface of lens side of  FIG. 1 ) functions as an attachment surface when the image-taking apparatus  100  is attached to the information processing apparatus  200 . Note that in each of  FIG. 3  to  FIG. 5 , the image-taking apparatus  100  is attached to the information processing apparatus  200  as an example. 
     The image-taking apparatus  100  is capable of taking images independently. Moreover, when the image-taking apparatus  100  is distant from the information processing apparatus  200 , the image-taking apparatus  100  is capable of taking images operated by the information processing apparatus  200 . The image-taking apparatus  100  is capable of taking images operated by the information processing apparatus  200 . The information processing apparatus  200  includes a display unit such as a liquid-crystal panel. The display unit displays stored images and images obtained by the image-taking apparatus  100 . A user watches the displayed image and operates the image-taking apparatus  100  at the same time such that it takes an image. 
     [Example of Way to Attach Image-Taking Apparatus] 
     Each of  FIG. 3  to  FIG. 5  is a diagram showing an external structure of the image-taking apparatus  100  of this embodiment attached to the information processing apparatus  200 . 
       FIG. 3  shows the image-taking apparatus  100  attached to one surface (surface on which input/output unit  240  is provided) of the information processing apparatus  200  as an example.  FIG. 4  shows the image-taking apparatus  100  attached to the other surface (surface opposite to surface on which input/output unit  240  is provided) of the information processing apparatus  200  as an example.  FIG. 5  shows the image-taking apparatus  100  attached to the other surface (surface opposite to surface on which input/output unit  240  is provided) of the information processing apparatus  200  as another example. For example, the information processing apparatus  200  is a smartphone, a tablet terminal, or the like. 
     The information processing apparatus  200  includes operation members  221  to  223 , the input/output unit  240 , an audio output unit  280 , a light emitter  291 , and an image-taking unit  250 . 
     The operation members  221  to  223  are used when a user inputs various kinds of operation. 
     The input/output unit  240  displays various images. The input/output unit  240  detects something coming close to or coming in contact with the display surface of the input/output unit  240 , and receives operations input by a user based on the detected status. 
     The audio output unit  280  is configured to output various kinds of audio information. 
     The light emitter  291  is a light-emitting device configured to emit light to an object. The light emitter  291  is used when the information processing apparatus  200  takes an image under an environment of insufficient brightness such as nighttime or an indoor environment for example. 
     The image-taking unit  250  is configured to take an object image, and to create an image (image data). 
     As shown in  FIG. 3  to  FIG. 5 , the attachment tools  181  and  182  of the image-taking apparatus  100  hold the body of the information processing apparatus  200 . As a result, the image-taking apparatus  100  is fixed to the information processing apparatus  200 . 
     [Configuration of Image-Taking Apparatus and Configuration of Information Processing Apparatus] 
       FIG. 6  is a block diagram showing the configuration of the image-taking apparatus  100  and the configuration of the information processing apparatus  200  of this embodiment. 
     (Configuration of Image-Taking Apparatus  100 ) 
     The image-taking apparatus  100  includes an image-taking unit  110 , storage  120 , a controller  130 , a Wi-Fi communication unit  140 , a NFC communication unit  150 , a brightness detector  180 , and a setting switch  170 . 
     The image-taking unit  110  is configured to take an object image of an object, and to create an image (image data). The image-taking unit  110  includes, for example, an optical system (plurality of lenses) and an image sensor. Moreover, the controller  130  controls the image-taking unit  110 . Specifically, the controller  130  controls the members (for example, zoom lens, focus lens, and diaphragm) of the image-taking unit  110 . 
     The storage  120  stores an image output from the image-taking unit  110 . Note that the Wi-Fi communication unit  140  may send the image to the information processing apparatus  200  side, and the information processing apparatus  200  side may store the image. 
     The storage  120  is a recording medium configured to store images of content (for example, still-image file, motion-image file). Note that the image-taking apparatus  100  may include built-in storage  120 , or the storage  120  may be removable. 
     The controller  130  is configured to control the blocks of the image-taking apparatus  100  based on controller programs. For example, the controller  130  is configured to control the blocks based on input operations received by operation members (not shown) of the image-taking apparatus  100  such as a zoom lever and a shutter key and by the setting switch  170 . 
     The controller  130  receives control information from the information processing apparatus  200  via the Wi-Fi communication unit  140 . The controller  130  controls the blocks based on the control information. In other words, the information processing apparatus  200  is capable of controlling the image-taking apparatus  100  remotely. The Wi-Fi communication unit  140  sends/receives various kinds of information (for example, control data and image data) to/from the information processing apparatus  200  via wireless communication. 
     The information processing apparatus  200  sends brightness information (external brightness information) corresponding to brightness of an object image of the information processing apparatus  200  side. The controller  130  receives the brightness information via the Wi-Fi communication unit  140 . In this embodiment, the controller  130  and the Wi-Fi communication unit  140  function as a receiver. 
     The controller  130  obtains brightness information (internal brightness information) from the brightness detector  180 . The controller  130  calculates an exposure value based on the brightness information (internal brightness information) and the brightness information (external brightness information) corresponding to the brightness of the object image of the information processing apparatus  200  side. The controller  130  controls exposure based on the exposure value. 
     In this embodiment, Wi-Fi (Wireless Fidelity) is used for wireless communication. Alternatively, for example, wireless communication such as Bluetooth (registered trademark), infrared, or radio waves for mobile phones may be used. 
     The NFC communication unit  150  detects that the image-taking apparatus  100  comes close to the information processing apparatus  200  via NFC (Near Field Communication). Moreover, the NFC communication unit  150  detects if the image-taking apparatus  100  is attached to the information processing apparatus  200 . Wireless communication is started as follows. The NFC communication unit  150  determines that the information processing apparatus  200  is near or attached to the image-taking apparatus  100 . Then, the image-taking apparatus  100  is powered on. After that, the image-taking apparatus  100  sends/receives data to/from the information processing apparatus  200  via the Wi-Fi communication unit  140 . Note that, instead of the NFC communication unit  150 , for example, a button, which is configured to mechanically detect attachment of the information processing apparatus  200 , may be provided and may detect the attached status. 
     The brightness detector  180  detects brightness of an object image. A photometric sensor may be used as the brightness detector  180 . Alternatively, brightness may be detected based on information from the image-taking unit  110 . 
     The setting switch  170  selects one of: to control exposure based on an exposure value corresponding to brightness information detected by the brightness detector  180 ; and to control exposure based on an exposure value, which is obtained by the information processing apparatus  200  by correcting brightness information detected by the brightness detector  180 . For example, a slidable switch is provided on the lens tube  160 , whereby the setting switch  170  is realized. The controller  130  controls exposure based on the exposure value calculated as described above depending on selection by the setting switch  170 . 
     (Configuration of Information Processing Apparatus  200 ) 
     The information processing apparatus  200  includes an operation receiver  210 , a Wi-Fi communication unit  220 , an NFC communication unit  230 , the input/output unit  240 , the image-taking unit  250 , storage  260 , and a controller  270 . 
     The operation receiver  210  is an operation receiver, and receives operations by a user. The operation receiver  210  outputs control information (operation information) to the controller  270  depending on the received operation. The operation receiver  210  corresponds to the operation members  221  to  223  of  FIG. 3  to  FIG. 5 , for example. 
     The Wi-Fi communication unit  220  sends/receives various kinds of information (for example, control data and image data) to/from the image-taking apparatus  100  via wireless communication. 
     The NFC communication unit  230  detects that the image-taking apparatus  100  comes close to the information processing apparatus  200 . Moreover, the NFC communication unit  230  detects if the image-taking apparatus  100  is attached to the information processing apparatus  200  or not. 
     Wireless communication is started as follows. The NFC communication unit  230  determines that the image-taking apparatus  100  is near or attached to the information processing apparatus  200 . Then, an image-taking application of the information processing apparatus  200  is started. After the image-taking application is started, the image-taking apparatus  100  sends/receives data to/from the Wi-Fi communication unit  220  of the information processing apparatus  200  via Wi-Fi communication. 
     The input/output unit  240  includes an input unit  241  and a display unit  242 . Controlled by the controller  270 , the input/output unit  240  displays various images on the display unit  242 . In addition, a user inputs operations in various image-taking operation members displayed on the display unit  242 . The input unit  241  of the input/output unit  240  receives the operations. Examples of the image-taking operation members include a zoom bar, a shutter key, and the like. Moreover, the input unit  241  outputs control information to the controller  270  depending on the input operation received by the input unit  241 . 
     For example, an electrostatic (electrostatic capacitive) touchscreen may be used as the input unit  241 . The electrostatic (electrostatic capacitive) touchscreen is configured to detect that an electrostatic capacity is changed, and to detect that something conductive (for example, finger of person) comes in contact with or comes close to the touchscreen based thereon. Moreover, for example, a display panel such as an LCD (Liquid-crystal Display) or an organic EL (electro luminescence) panel may be used as the display unit  242 . Moreover, for example, a transparent touchscreen is layered on the display surface of a display panel, whereby the input/output unit  240  is structured. 
     The image-taking unit  250  takes an object image, and creates an image (image data). The image-taking unit  250  includes, for example, an optical system and an image sensor. Moreover, the controller  270  controls the members (for example, focus lens and diaphragm) of the image-taking unit  250 . 
     The image-taking unit  250  outputs an image, and the storage  260  stores the image. Note that the storage  260  may store an image sent from the image-taking apparatus  100  side. 
     The storage  260  is a recording medium configured to store images of content (for example, still-image file, motion-image file). Note that the information processing apparatus  200  may include built-in storage  260 , or the storage  260  may be removable. 
     The controller  270  is configured to control the blocks of the information processing apparatus  200  based on controller programs. 
     For example, when the information processing apparatus  200  connects to the image-taking apparatus  100 , the controller  270  displays a display window on the input/output unit  240 . A user operates the display window to control the image-taking apparatus  100 . 
     The controller  270  is configured to detect brightness based on information from the image-taking unit  250 . In this embodiment, the image-taking unit  250  and the controller  270  function as a detector configured to detect brightness. Alternatively, a detector configured to detect brightness may be provided independent of the image-taking unit  250 . 
     The controller  270  is capable of sending brightness information depending on the detected brightness to the image-taking apparatus  100  via the Wi-Fi communication unit  220 . The controller  270  is capable of receiving setting information from the image-taking apparatus  100  via the Wi-Fi communication unit  220 . The setting information means that the brightness information is to be output to the image-taking apparatus  100  side. The controller  270  receives the setting information, and then sends brightness information to the image-taking apparatus  100  via the Wi-Fi communication unit  220 . In this embodiment, the controller  270  and the Wi-Fi communication unit  220  function as a receiver and an output unit. 
     [Behaviors of Image-Taking Apparatus and Information Processing Apparatus] 
     Next, behaviors of the image-taking apparatus  100  and the information processing apparatus  200  of this embodiment will be described. 
       FIG. 7  is a flowchart showing behaviors of the image-taking apparatus  100  of this embodiment. 
     As shown in  FIG. 7 , firstly, in Step S 101 , the NFC communication unit  150  detects an RF signal (wireless signal) having the NFC bandwidth from outside. The wireless signal corresponds to a polling command sent from the information processing apparatus  200 . A detector of the NFC communication unit  150 , which is configured to detect the frequency of a wireless signal having the NFC bandwidth, is capable of detecting the wireless signal. So the command is not decoded at this time. The NFC communication unit  150  recognizes that an RF signal having the NFC bandwidth is detected. 
     Next, if a wireless signal having the NFC bandwidth is detected (S 101 /Yes), in Step S 102 , the controller  130  outputs a power control signal to a power source (not shown). The power control signal instructs to power on the powered-off image-taking apparatus  100 . At this time, the controller  130  does not execute an image-taking preparation behavior. An example of the image-taking preparation behavior is to extend a retractable lens of the image-taking unit  110 . 
     Next, in Step S 103 , the controller  130  starts a timer for NFC communication. 
     Next, in Step S 104 , the controller  130  determines if response data has been sent or not via NFC communication depending on a check command from outside. The response data sent via NFC communication depending on a check command includes Wi-Fi Config and AAR (Android Application Record). 
     Next, if response data has been sent (S 104 /Yes), in Step S 105 , the controller  130  executes the image-taking preparation behavior. An example of the image-taking preparation behavior is to extend a retractable lens of the image-taking unit  110 . 
     Next, in Step S 106 , the controller  130  starts a camera function. For example, the controller  130  converts an object image, which is formed by the optical system including the retractable lens, into an electric image signal. Moreover, the controller  130  establishes Wi-Fi connection with the information processing apparatus  200 , and executes a link-function with the information processing apparatus  200 . Note that, if response data has not been sent (S 104 /No) and a time period (predetermined time period) set for the timer has passed (S 107 /Yes), in Step S 108 , the controller  130  outputs a power control signal to the power source (not shown). The power control signal instructs to power off the image-taking apparatus  100 . Moreover, if an RF signal (wireless signal) has not been detected and a power-button of the image-taking apparatus  100  is pressed (Step S 109 /Yes), the controller  130  outputs a power control signal to the power source (not shown). The power control signal instructs to power on the power-off image-taking apparatus  100 . At this time, the controller  130  executes the image-taking preparation behavior. An example of the image-taking preparation behavior is to extend a retractable lens of the image-taking unit  110  (Step S 110 ). The controller  130  starts the above-mentioned camera function (Step S 111 ). 
     Here,  FIG. 8  is a flowchart showing the behavior of the information processing apparatus  200 . 
     The NFC communication unit  230  at the information processing apparatus  200  side detects RF (wireless signal) having the NFC bandwidth from the image-taking apparatus  100  (Step S 201 ). Then the NFC communication unit  230  starts a predetermined application in accordance with AAR (Step S 202 ). Then the NFC communication unit  230  sends a Wi-Fi connection request to the image-taking apparatus  100  by using Wi-Fi Config. Then Wi-Fi connection is established between the information processing apparatus  200  and the image-taking apparatus  100 . Then link-function using Wi-Fi communication is executed. 
     The information processing apparatus  200  executes the above-mentioned predetermined application, i.e., the application for link-function, as shown in the following steps. 
     Firstly, the controller  270  sends/receives predetermined data via Wi-Fi communication, and determines if the linked image-taking apparatus  100  exists or not (Step S 203 ). 
     In Step S 203 , if the image-taking apparatus  100  exists, for example, the controller  270  sends the brightness information on the image of “B” of  FIG. 9 , which is obtained by the image-taking unit  250 , to the image-taking apparatus  100  side via Wi-Fi communication (Step S 204 ). 
     Meanwhile, with reference to  FIG. 7  again, the image-taking apparatus  100  links to the information processing apparatus  200 . Firstly, the controller  130  of the image-taking apparatus  100  sends/receives predetermined data via Wi-Fi communication, and determines if the linked information processing apparatus  200  exists or not (Step S 112 ). 
     Meanwhile, if the controller  130  determines that the information processing apparatus  200  exists in Step S 112 , the controller  130  obtains the above-mentioned brightness information on the image (see “B” of  FIG. 9 ), which is sent from the information processing apparatus  200 , via Wi-Fi communication (Step S 113 ). 
     The controller  130  corrects the brightness information on the image (see “A” of  FIG. 9 ) taken by the image-taking unit  110 , which is obtained by the brightness detector  180 , based on brightness information on the image (see “B” of  FIG. 9 ) at the information processing apparatus  200  side, whereby an exposure value is obtained. The controller  130  controls exposure based on the exposure value (Step S 114 ). The exposure-controlled image (see “D” of  FIG. 9 ) is sent to the information processing apparatus  200  side via Wi-Fi communication (Step S 115 ). 
     Here, with reference to  FIG. 8  again, the link-function application of the information processing apparatus  200  displays the above-mentioned image (see “D” of  FIG. 9 ), which is taken by the image-taking apparatus  100 , on the display unit  242  (Step S 205 ). If the input unit  241  is touched when the image (see “B” of  FIG. 9 ) is displayed (Step S 206 ), the information processing apparatus  200  sends information that the shutter is pressed to the image-taking apparatus  100  side via Wi-Fi communication (Step S 207 ). Moreover, if an image-taking apparatus does not exist (Step S 203 ), the information processing apparatus  200  displays an image taken by the information processing apparatus  200  (Step S 208 ) 
     With reference to  FIG. 7  again, the controller  130  of the image-taking apparatus  100  receives the information that the shutter is pressed from the information processing apparatus  200  side via Wi-Fi communication (Step S 116 ). Then the controller  130  stores the exposure-controlled image (e.g., still image) in the storage  120  (Step S 117 ). In this example, a still image is stored. Alternatively, a motion image is stored similarly. 
     Note that if the controller  130  does not determine that the information processing apparatus  200  exists (Step S 112 /No), the controller  130  obtains an exposure value based on the brightness information on the image (see “A” of  FIG. 9 ) taken by the image-taking unit  110 . The controller  130  controls exposure based on the exposure value (Step S 118 ). 
     As described above, in this embodiment, the image-taking apparatus  100  such as a lens-style camera links with the information processing apparatus  200  such as a smartphone. In such a system, the exposure-control accuracy may be increased by using brightness information obtained by the image-taking apparatus  100  and brightness information obtained by the information processing apparatus  200 . For example, brightness information on an image of a wide angle of view of the information processing apparatus  200  when the information processing apparatus  200  gets an overview of a close-up picture is used as additional information for automatic exposure when the image-taking apparatus  100  takes a picture close up (macro photography). 
     For example, as shown in  FIG. 10 , an object  302  is on a white table  301 . A user tries to take a picture of the object  302  close up by using the image-taking apparatus  100 . Then as shown in “A” of  FIG. 9 , since the image-taking apparatus  100  is close to the object  302 , if a picture is taken in the angle of view of the image-taking apparatus  100 , the background of the picture only contains the white table  301 . In this case, under the normal exposure control, if the background is white, the entire image is darkened as shown in “C” of  FIG. 9 . If an image is taken as it is, a dark image may be obtained. 
     To the contrary, because the information processing apparatus  200  is distant from the object  302  as shown in “B” of  FIG. 9 , an image of the entire image-taking environment may be taken in the angle of view of the information processing apparatus  200 . 
     As described above, brightness information on an image of a wide angle of view of the information processing apparatus  200  is used as additional information for automatic exposure when the image-taking apparatus  100  takes a picture close up. As a result, in this case, the information processing apparatus  200  informs the image-taking apparatus  100  that the background of the close-up image taken by the image-taking apparatus  100  is dark. As a result, as shown in “D” of  FIG. 9 , the exposure of the image-taking apparatus  100  is controlled appropriately, and the image is not darkened. 
     [Other Embodiments] 
     This technology is applicable to a wider technical field, and includes other various embodiments. Hereinafter, such embodiments will be disclosed. 
     (Example 1 of Selection of Apparatus) 
       FIG. 11  is a flowchart showing behaviors of the image-taking apparatus  100  according to another embodiment. 
     The first embodiment is based on the fact that the image-taking apparatus  100  takes a picture close up and that the information processing apparatus  200  gets an overview. However, in the following embodiment, a user may select one of the image-taking apparatus  100  and the information processing apparatus  200  as an apparatus, which takes a picture close up. 
     As shown in  FIG. 12 , for example, the image-taking apparatus  100  includes a switch  171 . In Step S 301 , if the image-taking apparatus  100  is selected to take a picture close up with the switch  171 , the image-taking apparatus  100  operates as an apparatus taking a picture close up and the information processing apparatus  200  operates as an apparatus getting an overview (Step S 302 ). 
     Meanwhile, in Step S 303 , if the information processing apparatus  200  is selected to take a picture close up with the switch  171 , the information processing apparatus  200  operates as an apparatus taking a picture close up and the image-taking apparatus  100  operates as an apparatus getting an overview (Step S 304 ). In this case, the image-taking apparatus  100  sends brightness information to the information processing apparatus  200  side. The information processing apparatus  200  corrects brightness information obtained by the information processing apparatus  200  based on the brightness information sent from the image-taking apparatus  100 , to thereby obtain an exposure value. The information processing apparatus  200  controls exposure based on the exposure value. 
     Because of this, a user is capable of selecting an apparatus, which takes a picture close up. In addition, it is possible to control exposure more accurately. 
     Note that not the image-taking apparatus  100  but the information processing apparatus  200  may include this kind of switch.  FIG. 13  shows an example. The display unit  242  of the information processing apparatus  200  displays a toggle UI button  243 . A user may select an apparatus, which takes a picture close up, by touching the button  243 . 
     (Example 2 of Selection of Apparatus) 
       FIG. 14  is a flowchart showing behaviors of the information processing apparatus  200  according to another embodiment. 
     In this embodiment, as shown in  FIG. 15 , the image-taking apparatus  100  in a pair is contained in the angle of view of the information processing apparatus  200 . The information processing apparatus  200  is selected to obtain an image of a wide angle of view. The information processing apparatus  200  sends an instruction to the image-taking apparatus  100  to take a picture close up via Wi-Fi communication. 
     For example, as shown in  FIG. 14 , in Step S 401 , the information processing apparatus  200  processes an image, and determines if the image-taking apparatus  100 , which may be in a pair, is contained in the angle of view of an image taken by the information processing apparatus  200  or not. 
     If the image-taking apparatus  100  is contained in Step S 401 , the information processing apparatus  200  sets up itself to obtain an image of a wide angle of view (Step S 402 ), and sends an instruction to the image-taking apparatus  100  to take a picture close up (Step S 403 ). 
     Meanwhile, if the image-taking apparatus  100  is not contained in Step S 401 , the information processing apparatus  200  determines whether it receives an instruction to be an apparatus taking a picture close up or not from an apparatus. Specifically, the information processing apparatus  200  determines whether it receives an instruction to be an apparatus taking a picture close up from an apparatus, which is set up to obtain an image of a wide angle of view (Step S 404 ). If the image-taking apparatus  100  receives the instruction to be an apparatus taking a picture close up in Step S 404 , then the information processing apparatus  200  sets up itself to take a picture close up (Step S 405 ). 
     (Examples of User Interface) 
     Next, examples of user interfaces of the information processing apparatus  200  of this technology will be described. 
     Each of  FIG. 16  and  FIG. 17  shows a display window displayed on the display unit  242 , which is a user interface of the information processing apparatus  200 . 
     As shown in  FIG. 16 , when the image-taking apparatus  100  takes an image in a normal mode, the display unit  242  of the information processing apparatus  200  displays a live view image taken by the image-taking apparatus  100 . A user is capable of confirming the image taken by the image-taking apparatus  100 . At the same time, a brightness-mode button  245  and a shutter button  246  are displayed in a predetermined area of the display unit  242 , for example. The brightness-mode button  245  is used to brightness of one of two apparatuses. In  FIG. 16 , an exposure-controlled image based on an exposure value determined based on brightness information on the image-taking apparatus  100 , is displayed on the display unit. The information processing apparatus  200  is capable of taking the displayed image. 
     Here, if the button  245  of the information processing apparatus  200  is touched, as shown in  FIG. 17 , an image whose exposure is controlled based on an exposure value, which is obtained by correcting the brightness information on the image-taking apparatus  100  based on the brightness information on the information processing apparatus  200 , is displayed. The information processing apparatus  200  is capable of taking the displayed image. 
     Note that  FIG. 17  shows an example of automatic exposure control. For example, the information processing apparatus  200  may also be capable of executing a semi-automatic exposure-control mode. As shown in  FIG. 18 , the display unit  242  may display an exposure-correction setting bar  247 . Exposure may be corrected when a user touches the bar  247 . As a result, exposure may be corrected just as a user intended. In this case, the display unit  242  may display both an image (live-view image)  248  taken by the information processing apparatus  200  and an image (live-view image)  249  taken by the image-taking apparatus  100 . In this case, the display area of the image  249  is larger than the display area of the image  248 . As a result, a user is capable of easily recognizing an image to be taken. 
     This technology is not limited to the above-mentioned embodiments, and may be variously modified within the scope of this technology. 
     Note that this technology may employ the following configurations. 
     (1) An image-taking apparatus, including: 
     a detector configured to detect brightness of an object image, and to output internal brightness information; and 
     a controller configured to control exposure based on an exposure value, the exposure value being based on the internal brightness information and external brightness information received from an external apparatus. 
     (2) The image-taking apparatus according to (1), further including: 
     a setting unit configured to select one of a first exposure value and a second exposure value to be used, the first exposure value being based on the internal brightness information, the second exposure value being based on both of the internal brightness information and the external brightness information, in which 
     the controller is configured to control exposure based on one of the first exposure value and the second exposure value selected by the setting unit. 
     (3) The image-taking apparatus according to (1) or (2), further including: 
     an output unit configured to output an image to the external apparatus, the image being taken with exposure controlled by the controller. 
     (4) The image-taking apparatus according to any one of (1) to (3), in which 
     the controller is configured to control exposure based on a first exposure value if the external apparatus does not exist and based on a second exposure value if the external apparatus exists, the first exposure value being based on the internal brightness information, the second exposure value being based on both of the internal brightness information and the external brightness information. 
     (5) The image-taking apparatus according to any one of (1) to (4), further including: 
     a wireless receiver configured to receive the external brightness information. 
     (6) The image-taking apparatus according to any one of (1) to (5), in which 
     the controller is configured to correct the internal brightness information based on the external brightness information to thereby obtain the exposure value. 
     (7) The image-taking apparatus according to any one of (1) to (6), in which 
     the image-taking apparatus is capable of being fixed to the information processing apparatus. 
     (8) An information processing apparatus, including: 
     a detector configured to detect brightness of an object image; 
     a determining unit configured to determine if an external image-taking apparatus exists or not; and 
     an output unit configured to output the brightness information to the image-taking apparatus if the image-taking apparatus exists. 
     (9) The information processing apparatus according to (8), further including: 
     a receiver configured to receive an image sent from the image-taking apparatus. 
     (10) The information processing apparatus according to (8) or (9), further including: 
     a controller configured to display an image received by the receiver on a display unit. 
     (11) The information processing apparatus according to any one of (8) to (10), further including: 
     an image-taking unit configured to take an object image, in which 
     the controller is configured to display an image obtained by the image-taking unit and an image received by the receiver on the display unit at the same time. 
     (12) The information processing apparatus according to any one of (8) to (11), in which 
     the output unit is configured to output the brightness information wirelessly. 
     (13) An image-taking system, including: 
     an information processing apparatus including 
     a detector configured to detect brightness of an object image, and to output external brightness information, 
     a determining unit configured to determine if an external image-taking apparatus exists or not, and 
     an output unit configured to output the external brightness information to the image-taking apparatus if the image-taking apparatus exists; and 
     an image-taking apparatus including 
     a detector configured to detect brightness of an object image, and to output internal brightness information, and 
     a controller configured to control exposure based on an exposure value, the exposure value being based on the internal brightness information detected by the detector and external brightness information received from an external apparatus.