Patent Publication Number: US-11659277-B2

Title: Imaging apparatus and imaging method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of U.S. patent application Ser. No. 16/574,162, filed on Sep. 18, 2019, which is a continuation application of U.S. patent application Ser. No. 15/022,145, filed on Mar. 15, 2016 (now U.S. Pat. No. 10,440,252 issued Oct. 8, 2019), which is a National Phase Patent Application of International Application No. PCT/JP2014/074241 filed on Sep. 12, 2014, and which claims priority from Japanese Patent Application JP 2013-197389 filed on Sep. 24, 2013. Each of the above referenced applications is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to an imaging apparatus, an imaging method, and a program, and particularly to, an imaging apparatus, an imaging method, and a program that are capable of easily setting a type of a subject as a focusing target in each imaging. 
     BACKGROUND ART 
     Imaging apparatuses have a function of detecting a specific subject such as a human face within an image and bringing the subject into focus (see, for example, Patent Document 1). 
     Patent Document 1: Japanese Patent Application Laid-open No. 2009-118009 
     SUMMARY OF INVENTION 
     Problem to be Solved by the Invention 
     However, a type of a subject as a focusing target could not be easily set in each imaging. 
     The present disclosure has been made in view of such circumstances and is capable of easily setting a type of a subject as a focusing target in each imaging. 
     Means for Solving the Problem 
     According to an aspect of the present disclosure, there is provided an imaging apparatus including: an acquisition unit that acquires an image; a first selection unit that selects a first type of a subject as a focusing target in each imaging of the image acquired by the acquisition unit; a first detection unit that detects an area of the subject of the first type from the image in a case where the first type is selected by the first selection unit; and an area setting unit that sets the area detected by the first detection unit as an in-focus area of the image. 
     According to an aspect of the present disclosure, there are provided an imaging method and a program that correspond to the imaging apparatus according to one aspect of the present disclosure. 
     In one aspect of the present disclosure, an image is acquired, a first type of a subject as a focusing target is selected in each imaging of the image, an area of the subject of the first type is detected from the image in a case where the first type is selected, and the area is set as an in-focus area of the image. 
     Effects of the Invention 
     According to one aspect of the present disclosure, imaging can be performed with a subject being in focus. Further, according to one aspect of the present disclosure, a type of a subject as a focusing target can be easily set in each imaging. 
     It should be noted that effects described herein are not necessarily limited and any one of the effects described herein may be produced. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a front view showing an outer appearance configuration example of a first embodiment of an imaging apparatus to which the present disclosure is applied. 
         FIG.  2    is a back view showing an outer appearance configuration example of the imaging apparatus of  FIG.  1   . 
         FIG.  3    is a top view showing an outer appearance configuration example of the imaging apparatus of  FIG.  1   . 
         FIG.  4    is a block diagram showing a hardware configuration example of the imaging apparatus of  FIG.  1   . 
         FIG.  5    is a block diagram showing a configuration example of an in-focus area control unit of the first embodiment of the imaging apparatus. 
         FIG.  6    is a diagram showing an example of a setting screen of a face detection function. 
         FIG.  7    is a diagram for describing a relationship between a face detection mode and face frame display. 
         FIG.  8    is a diagram for describing a relationship between a face detection mode and an in-focus area. 
         FIG.  9    is a diagram for describing display in the face detection mode. 
         FIG.  10    is a diagram for describing display in a face detection ON mode. 
         FIG.  11    is a flowchart for describing face detection OFF imaging processing according to the first embodiment of the imaging apparatus. 
         FIG.  12    is a flowchart for describing face detection ON imaging processing according to the first embodiment of the imaging apparatus. 
         FIG.  13    is a block diagram showing a configuration example of an in-focus area control unit of a second embodiment of an imaging apparatus to which the present disclosure is applied. 
         FIG.  14    is a block diagram showing a configuration example of an in-focus area control unit of a third embodiment of an imaging apparatus to which the present disclosure is applied. 
         FIG.  15    is a flowchart for describing face detection OFF imaging processing according to the third embodiment of the imaging apparatus. 
         FIG.  16    is a flowchart for describing face detection ON imaging processing according to the third embodiment of the imaging apparatus. 
         FIG.  17    is a block diagram showing a hardware configuration example of a computer. 
     
    
    
     MODE(S) FOR CARRYING OUT THE INVENTION 
     First Embodiment 
     (Outer Appearance Configuration Example of First Embodiment of Imaging Apparatus) 
       FIGS.  1  to  3    are views each showing an outer appearance configuration example of a first embodiment of an imaging apparatus to which the present disclosure is applied.  FIG.  1    is a front view of the imaging apparatus.  FIG.  2    is a back view of the imaging apparatus.  FIG.  3    is a top view of the imaging apparatus. 
     It should be noted that in this specification, a surface on which a lens of the imaging apparatus is disposed is a front surface, and a surface opposed to the front surface is a back surface. Further, a direction perpendicular to the front surface and the back surface is a depth direction. 
     As shown in  FIG.  1   , a lens  10 A is disposed on the front surface of an imaging apparatus  10  at the center of the right side when viewed from a subject. The lens  10 A collects light from the subject. 
     Further, as shown in  FIGS.  1  to  3   , a release button  11  is disposed on the top surface of the imaging apparatus  10  on the left side when viewed from the subject. The release button  11  is full pressed when imaging is performed. Further, the release button  11  is half pressed when a predetermined area within an image (for example, a center area of the image, an area of the subject in which a position in the depth direction is closest to the imaging apparatus  10 , or the like) is brought into focus. As shown in  FIG.  3   , the release button  11  is provided with a power button  11 A. The power button  11 A is operated when the power of the imaging apparatus  10  is turned on. 
     As shown in  FIGS.  1  to  3   , on the top surface of the imaging apparatus  10 , additionally, a mode dial  12  is disposed on the right side of the release button  11  and a custom button  13  is disposed on the left side thereof when viewed from the subject. The mode dial  12  is operated when an imaging mode is selected. The custom button  13  is a button to which a user can assign a desired function. 
     As shown in  FIGS.  1  and  3   , a front dial  14  is disposed on the front surface of the imaging apparatus  10  on the upper left side of the lens  10 A when viewed from the subject. The front dial  14  is operated when a shutter speed is adjusted, for example. 
     As shown in  FIG.  1   , a lens lock button  15  is disposed adjacently to the lens  10 A on the front surface of the imaging apparatus  10 . The lens lock button  15  is operated when the lens  10 A is removed from the imaging apparatus  10 . 
     As shown in  FIG.  2   , a menu button  16  is disposed on the back surface of the imaging apparatus  10  on the upper left side toward the subject. The menu button  16  is pressed when a menu screen is displayed. 
     Further, as shown in  FIG.  2   , a finder  17  is disposed on the back surface of the imaging apparatus  10  on the upper right side of the menu button  16  toward the subject, and a diopter adjusting dial  17 A is disposed on the right side of the finder  17  toward the subject. The finder  17  is a liquid crystal panel for confirming the subject when imaging is performed. 
     The diopter adjusting dial  17 A is operated when the diopter of the finder  17  is adjusted. The user operates the diopter adjusting dial  17 A such that an image displayed on the finder  17  is easy to see. This enables an image appropriate to the eyesight of the user to be displayed on the finder  17 . 
     As shown in  FIGS.  2  and  3   , a custom button  18  is disposed on the back surface of the imaging apparatus  10  on the lower right side of the finder  17  toward the subject, and a rear dial  19  is disposed on the right side of the custom button  18  toward the subject. The custom button  18  is a button to which a user can assign a desired function, like the custom button  13 . The rear dial  19  is operated when an aperture value is adjusted, for example. 
     As shown in  FIG.  2   , a recording button  20  is disposed on the lower right side of the rear dial  19  toward the subject on the back surface of the imaging apparatus  10 . The recording button  20  is pressed when a moving image is captured. 
     Further, as shown in  FIG.  2   , an AEL button  21  is disposed on the lower side of the custom button  18  on the back surface of the imaging apparatus  10 , and an Fn button  22  is disposed on the lower side of the AEL button  21 . The AEL button  21  is pressed when the exposure of the entire screen is fixed, for example. The Fn button  22  is pressed when a setting screen on which functions on various types of imaging are set is displayed. 
     As shown in  FIG.  2   , a cross key  23  is disposed below the Fn button  22  on the back surface of the imaging apparatus  10 . The cross key  23  is constituted by an upper button  23 A, a lower button  23 B, a left button  230 , a right button  23 D, and a center button  23 E. The buttons  23 A to  23 D of the cross key  23  are each pressed when a cursor or the like within a menu screen or setting screen displayed on a liquid crystal monitor  26  is moved right and left and up and down. 
     The center button  23 E is pressed when an instruction of a decision is given on a menu screen or setting screen displayed on the liquid crystal monitor  26 , for example. Further, the center button  23 E is pressed when a pupil is selected as a type of a subject serving as a focusing target in each imaging in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 . In other words, the center button  23 E in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26  functions as a selection unit that selects a pupil as a type of a subject serving as a focusing target in each imaging. 
     As shown in  FIG.  2   , a reproduction button  24  is disposed on the lower left side of the cross key  23  toward the subject on the back surface of the imaging apparatus  10 , and a delete button  25  is disposed on the lower right side thereof. The reproduction button  24  is pressed when a captured image is reproduced. The delete button  25  is pressed when a captured image displayed on the liquid crystal monitor  26  is deleted. 
     As shown in  FIG.  2   , the liquid crystal monitor  26  is disposed on the left side toward the subject on the back surface of the imaging apparatus  10 . A menu screen, a setting screen, a captured image, and the like are displayed on the liquid crystal monitor  26 . 
     (Hardware Configuration Example of Imaging Apparatus) 
       FIG.  4    is a block diagram showing a hardware configuration example of the imaging apparatus  10 . 
     The imaging apparatus  10  of  FIG.  1    includes an optical system  41 , an image sensor  42 , an image processing unit  43 , a compression processing unit  44 , a medium control unit  45 , a recording medium  46 , a focusing control unit  48 , and a microcomputer  47 . Further, the imaging apparatus  10  includes the focusing control unit  48 , an actuator  49 , a display unit  50 , a memory  51 , and an operation unit  52 . 
     When the center button  23 E is pressed in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , the imaging apparatus  10  brings a pupil within an image into focus. 
     Specifically, the optical system  41  and the image sensor  42  function as an acquisition unit and acquire an image. More specifically, the optical system  41  is constituted by the lens  10 A, a diaphragm not shown in the figure, and the like. The optical system  41  collects light from the subject to the image sensor  42 . The optical system  41  is driven by the actuator  49 . 
     The image sensor  42  performs photoelectric conversion on the light collected by the lens  10 A on a pixel-by-pixel basis and acquires an electrical signal as an analog signal of each pixel of the image. Further, the image sensor  42  acquires phase difference information on the basis of the light collected by the optical system  41  in each detection using one or more pixels. The phase difference information represents a displacement amount of the image from an in-focus surface. The image sensor  42  supplies the electrical signal of each pixel to the image processing unit  43  and supplies the phase difference information to the focusing control unit  48 . 
     The image processing unit  43  performs image processing such as A/D conversion on the electrical signal of each pixel of the image supplied from the image sensor  42 . The image processing unit  43  supplies image data, which is resultant digital data of each pixel of the image, to the compression processing unit  44  and the microcomputer  47 . 
     The compression processing unit  44  compresses the image data supplied from the image processing unit  43  as necessary. The compression processing unit  44  supplies the compressed image data to the medium control unit  45 . 
     The medium control unit  45  controls the recording medium  46  to record the compressed image data supplied from the compression processing unit  44  on the recording medium  46 . In such a manner, the processing in which an image is acquired by the image sensor  42  and then compressed and the compressed image data is recorded is called imaging. The recording medium  46  records the compressed image data under the control of the medium control unit  45 . 
     The microcomputer  47  controls the units of the imaging apparatus  10 . For example, the microcomputer  47  sets a face detection mode on the basis of an operation signal representing an operation from a user and being supplied from the operation unit  52 , and supplies the face detection mode to the memory  51  to be stored. The microcomputer  47  causes the liquid crystal monitor  26  of the display unit  50  to display a menu screen or setting screen on the basis of the operation signal or causing the display unit  50  to display an image based on the image data from the image processing unit  43 . 
     Further, the microcomputer  47  functions as an in-focus area control unit that controls the in-focus area. Specifically, the microcomputer  47  detects a face area from the image data supplied from the image processing unit  43 . Further, the microcomputer  47  detects a pupil area from the image data on the basis of the face area and an operation signal representing a press of the center button  23 E and being supplied from the operation unit  52 , when a menu screen or setting screen is not displayed on the liquid crystal monitor  26 . The microcomputer  47  sets the face area, the pupil area, or a predetermined area as an in-focus area on the basis of the face detection mode stored in the memory  51  and the operation signal, and supplies the in-focus area to the focusing control unit  48 . 
     The focusing control unit  48  controls the actuator  49  to bring the in-focus area into focus on the basis of the in-focus area supplied from the microcomputer  47  and the phase difference information supplied from the image sensor  42 . 
     The actuator  49  is controlled by the focusing control unit  48  and the like. The actuator  49  drives the optical system  41  and controls a focus position, an aperture value, and a zoom magnification. 
     The display unit  50  is constituted by the finder  17  and the liquid crystal monitor  26  shown in  FIG.  2   . The display unit  50  displays a captured image on the basis of the image data of the captured image (compressed and recorded image) under the control of the microcomputer  47 . Further, the display unit  50  displays an image based on image data of an image that is not a captured image (that is an image not compressed and recorded), as a live-view image, under the control of the microcomputer  47 . The liquid crystal monitor  26  of the display unit  50  displays a menu screen or setting screen under the control of the microcomputer  47 . 
     The memory  51  is a work area of the microcomputer  47 . The memory  51  stores an interim result or a final result of the processing by the microcomputer  47 . For example, the memory  51  stores the face detection mode supplied from the microcomputer  47 . 
     The operation unit  52  supplies an operation signal to the microcomputer  47 , the operation signal representing operations of the release button  11 , the power button  11 A, the mode dial  12 , the custom button  13 , the front dial  14 , the menu button  16 , the diopter adjusting dial  17 A, and the custom button  18 . Further, the operation unit  52  supplies an operation signal to the microcomputer  47 , the operation signal representing operations of the rear dial  19 , the recording button  20 , the AEL button  21 , the Fn button  22 , the cross key  23 , the reproduction button  24 , and the delete button  25 . 
     (Configuration Example of In-Focus Area Control Unit) 
       FIG.  5    is a block diagram showing a configuration example of the in-focus area control unit achieved by the microcomputer  47  of  FIG.  4   . 
     An in-focus area control unit  70  of  FIG.  5    is constituted by a face detection unit  71 , a pupil detection unit  72 , an area setting unit  73 , and a display control unit  74 . 
     The face detection unit  71  of the in-focus area control unit  70  reads the face detection mode from the memory  51 . The face detection unit  71  detects a face area from the image data supplied from the image processing unit  43 , on the basis of the face detection mode. The face detection unit  71  supplies the face area to the pupil detection unit  72 , the area setting unit  73 , and the display control unit  74 . 
     The pupil detection unit  72  reads the face detection mode from the memory  51 . The pupil detection unit  72  determines whether an operation signal representing a press of the center button  23 E is supplied from the operation unit  52  or not in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 . The pupil detection unit  72  detects a pupil area from the image data on the basis of a determination result, the face detection mode, and the face area supplied from the face detection unit  71 . The pupil detection unit  72  supplies the pupil area to the area setting unit  73 . 
     The area setting unit  73  reads the face detection mode from the memory  51 . The area setting unit  73  sets the face area, the pupil area, or a predetermined area as an in-focus area in each imaging on the basis of the face detection mode and the operation signal representing a half-press of the release button  11  and being supplied from the operation unit  52 . The area setting unit  73  supplies the in-focus area to the display control unit  74  and the focusing control unit  48  of  FIG.  4   . 
     The display control unit  74  reads the face detection mode from the memory  51 . The display control unit  74  superimposes a face frame, which represents the face area supplied from the face detection unit  71 , on a live-view image being displayed, on the basis of the face detection mode, for display on the display unit  50 . Further, the display control unit  74  superimposes a frame, which represents the in-focus area supplied from the area setting unit  73 , on a live-view image being displayed, for display on the display unit  50 . 
     (Example of Setting Screen of Face Detection Function) 
       FIG.  6    is a diagram showing an example of a setting screen of the face detection function displayed on the liquid crystal monitor  26 . 
     The setting screen of the face detection function is displayed when the user presses the Fn button  22 . 
     As shown in  FIG.  6   , a setting screen  80  of the face detection function includes a face detection OFF mode button  81 . The face detection OFF mode button  81  is operated when a face detection OFF mode for bringing the face area out of focus is selected as the face detection mode. 
     The setting screen  80  includes a registered face mode button  82 . The registered face mode button  82  is operated when a registered face detection mode for preferentially bringing an area of a registered face image, which is a previously registered face image, into focus more than other face areas is selected as the face detection mode. 
     It should be noted that the image data of the registered face image is stored in the memory  51 , for example. In the case where the face detection mode is the registered face detection mode, the face detection unit  71  performs matching between the image data supplied from the image processing unit  43  and the image data of the registered face image, to detect an area of the registered face image as a face area. In the case where an area of the registered face image is not detected, the face detection unit  71  detects an area of a face image other than the registered face image as a face area. 
     The setting screen  80  includes a face detection ON mode button  83 . The face detection ON mode button  83  is operated when a face detection ON mode for bringing the face area into focus is selected as the face detection mode. Further, the setting screen  80  includes a smile shutter mode button  84 . The smile shutter mode button  84  is operated when a smile shutter mode for capturing an image in which a smile is detected is selected as the face detection mode. 
     A cursor  85  is superimposed on any of the face detection OFF mode button  81 , the registered face mode button  82 , the face detection ON mode button  83 , and the smile shutter mode button  84  within the setting screen  80 , and displayed. 
     The user presses the buttons  23 A to  23 D of the cross key  23  and thus moves the cursor  85 . When the cursor  85  is then superimposed on the face detection OFF mode button  81 , the registered face mode button  82 , the face detection ON mode button  83 , or the smile shutter mode button  84  that corresponds to a desired face detection mode, the user presses the center button  23 E. 
     This enables the setting of the face detection mode that corresponds to the face detection OFF mode button  81 , the registered face mode button  82 , the face detection ON mode button  83 , or the smile shutter mode button  84  on which the cursor  85  is superimposed. In the example of  FIG.  6   , the cursor  85  is superimposed on the registered face mode button  82 . When the center button  23 E is pressed at that time, the registered face detection mode is set as the face detection mode. 
     (Description on Relationship Between Face Detection Mode and Face Frame Display) 
       FIG.  7    is a diagram for describing a relationship between a face detection mode and face frame display for an image before an instruction of focusing is given by a half-press of the release button  11  or a press of the center button  23 E. 
     As shown in  FIG.  7   , even in the case where the face detection mode is any of the face detection OFF mode, the registered face detection mode, the face detection mode, and the smile shutter mode, the face detection unit  71  performs face detection. 
     In the case where the face detection mode is the face detection OFF mode, however, the face frame is not superimposed on a live-view image being displayed, before an instruction of focusing is given. In the case where the face detection mode is other than the face detection OFF mode, the face frame is superimposed on a live-view image being displayed, before an instruction of focusing is given. 
     (Description on Relationship Between Face Detection Mode and in-Focus Area) 
       FIG.  8    is a diagram for describing a relationship between the face detection mode and the in-focus area. 
     As shown in  FIG.  8   , in the case where the face detection mode is other than the smile shutter mode, when the center button  23 E of the cross key  23  is pressed in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , the in-focus area is set for the pupil area. In the case where the face detection mode is the registered face detection mode and an area of the registered face image is detected, the pupil area is an area of a pupil in the registered face image. 
     On the other hand, in the case where the face detection mode is the smile shutter mode, when the center button  23 E is pressed in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , the in-focus area is set for the face area. 
     Further, when the release button  11  is half pressed in the case where the face detection mode is the face detection OFF mode, the in-focus area is set for the predetermined area. On the other hand, when the release button  11  is half pressed in the case where the face detection mode is other than the face detection OFF mode, the in-focus area is set for the face area. In the case where the face detection mode is the registered face detection mode and an area of the registered face image is detected, the face area is the area of the registered face image. 
     (Description on Display in Face Detection OFF Mode) 
       FIG.  9    is a diagram for describing display on the display unit  50  in the face detection mode. 
     As shown in  FIG.  9   , in the face detection mode, in the case where an instruction of focusing is given by pressing the center button  23 E of the cross key  23  in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , nothing is superimposed on a live-view image  91  being displayed, before the instruction of focusing is given. 
     After the instruction of focusing is given, a pupil area is detected by the pupil detection unit  72 . In the case where a pupil area is detected, the in-focus area is set for the pupil area by the area setting unit  73 , and a pupil frame  101  representing a pupil area as the in-focus area is superimposed on a live-view image  92  being displayed. The pupil area represented by the pupil frame  101  is then brought into focus. On the other hand, in the case where the pupil area is not detected, the in-focus area is set for the face area by the area setting unit  73 , and a face frame  102  representing the face area as the in-focus area is superimposed on the live-view image  92  being displayed. The face area represented by the face frame  102  is then brought into focus. After focusing is achieved, nothing is superimposed again on a live-view image  93  being displayed. 
     Further, in the face detection OFF mode, in the case where an instruction of focusing is given by half pressing the release button  11 , nothing is superimposed on the live-view image  91  being displayed, before the instruction of focusing is given. After the instruction of focusing is given, the in-focus area is set for the predetermined area by the area setting unit  73 , and a predetermined frame  103  representing a predetermined area as the in-focus area is superimposed on the live-view image  92  being displayed. The predetermined area represented by the predetermined frame  103  is then brought into focus. It should be noted that in the example of  FIG.  9   , the predetermined area is an area of a subject whose position in the depth direction is closest to the imaging apparatus  10 . After focusing is achieved, the predetermined frame  103  remains superimposed on the live-view image  93  being displayed. 
     (Description on Display in Face Detection ON Mode) 
       FIG.  10    is a diagram for describing display on the display unit  50  in the face detection ON mode. 
     As shown in  FIG.  10   , in the face detection ON mode, in the case where an instruction of focusing is given by pressing the center button  23 E of the cross key  23  in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , a temporary face frame  121  representing a face area as a candidate of the in-focus area is superimposed on a live-view image  111  being displayed, before an instruction of focusing is given. 
     After the instruction of focusing is given, a pupil area is detected by the pupil detection unit  72 . In the case where a pupil area is detected, the in-focus area is set for the pupil area by the area setting unit  73 , and a pupil frame  122  representing a pupil area as the in-focus area is superimposed on a live-view image  112  being displayed. The pupil area represented by the pupil frame  122  is then brought into focus. On the other hand, in the case where the pupil area is not detected, the in-focus area is set for the face area by the area setting unit  73 , and a face frame  123  representing the face area as the in-focus area is superimposed on the live-view image  112  being displayed. The face area represented by the face frame  123  is then brought into focus. After focusing is achieved, the face frame  123  is superimposed on a live-view image  113  being displayed. 
     Further, in the face detection ON mode, in the case where an instruction of focusing is given by half pressing the release button  11 , the temporary face frame  121  is superimposed on the live-view image  111  being displayed, before the instruction of focusing is given. After the instruction of focusing is given, the in-focus area is set for the face area by the area setting unit  73 , and the face frame  123  is superimposed on the live-view image  112  being displayed. After focusing is achieved, the face frame  123  remains superimposed on the live-view image  113  being displayed. 
     In order to easily recognize that the temporary face frame  121  represents not the in-focus area but a candidate of the in-focus area, the temporary face frame  121 , the pupil frame  122 , and the face frame  123  may be changed in color, thickness, type of line, and the like. 
     (Description on Processing of Imaging Apparatus) 
       FIG.  11    is a flowchart for describing the face detection OFF imaging processing that is imaging processing of the imaging apparatus  10  in the case where the face detection mode is the face detection OFF mode. This face detection OFF imaging processing is started when the power is turned on by operating the power button  11 A, for example. 
     In Step S 11  of  FIG.  11   , the image sensor  42  acquires an electrical signal of each pixel of the image by performing photoelectric conversion on light from the subject, the light being collected via the optical system  41 , on a pixel-by-pixel basis. The image sensor  42  supplies the electrical signal of each pixel of the image to the image processing unit  43 , and thus the image data is supplied to the compression processing unit  44  and the microcomputer  47 . 
     In Step S 12 , the microcomputer  47  displays an image based on the image data supplied from the image processing unit  43 , as a live-view image, on the display unit  50 . 
     In Step S 13 , the face detection unit  71  of the microcomputer  47  detects a face area from the image data supplied from the image processing unit  43 . The face detection unit  71  supplies the face area to the pupil detection unit  72 , the area setting unit  73 , and the display control unit  74 . 
     In Step S 14 , the pupil detection unit  72  determines whether the center button  23 E of the cross key  23  is pressed or not in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , on the basis of an operation signal from the operation unit  52 . In Step S 14 , when it is determined that the center button  23 E is pressed, the processing proceeds to Step S 15 . 
     In Step S 15 , the pupil detection unit  72  detects a pupil area from the image data supplied from the image processing unit  43 , on the basis of the face area supplied from the face detection unit  71 . 
     In Step S 16 , the pupil detection unit  72  determines whether a pupil area is detected or not by the processing of Step S 15 . When it is determined in Step S 16  that a pupil area is detected, the pupil detection unit  72  supplies the detected pupil area to the area setting unit  73 . In Step S 17 , the area setting unit  73  then sets the pupil area, which is supplied from the pupil detection unit  72 , as the in-focus area, and supplies the pupil area to the display control unit  74  and the focusing control unit  48  of  FIG.  4   . 
     In Step S 18 , the display control unit  74  superimposes a pupil frame on a live-view image being displayed, on the basis of the pupil area supplied from the area setting unit  73 , for display on the display unit  50 . The processing then proceeds to Step S 24 . 
     On the other hand, when it is determined in Step S 16  that a pupil area is not detected, in Step S 19 , the area setting unit  73  sets the face area, which is supplied from the face detection unit  71 , as the in-focus area, and supplies the face area to the display control unit  74  and the focusing control unit  48 . 
     In Step S 20 , the display control unit  74  superimposes a face frame on a live-view image being displayed, on the basis of the face area supplied from the area setting unit  73 , for display on the display unit  50 . The processing then proceeds to Step S 24 . 
     Further, when it is determined in Step S 14  that the center button  23 E is not pressed, the processing proceeds to Step S 21 . In Step S 21 , the area setting unit  73  determines whether the release button  11  is half pressed or not, on the basis of the operation signal supplied from the operation unit  52 . 
     When it is determined in Step S 21  that the release button  11  is half pressed, in Step S 22 , the area setting unit  73  sets a predetermined area as the in-focus area and supplies the predetermined area to the display control unit  74  and the focusing control unit  48 . 
     In Step S 23 , the display control unit  74  superimposes a predetermined frame on a live-view image being displayed, on the basis of the predetermined area supplied from the area setting unit  73 , for display on the display unit  50 . The processing then proceeds to Step S 24 . 
     In Step S 24 , the image sensor  42  acquires phase difference information, and the focusing control unit  48  controls the actuator  49  to bring the in-focus area into focus on the basis of the in-focus area from the area setting unit  73  and the phase difference information from the image sensor  42 , to drive the optical system  41 . 
     In Step S 25 , the image sensor  42  acquires an electrical signal of each pixel of the image by performing photoelectric conversion on light from the subject, the light being collected via the optical system  41 , on a pixel-by-pixel basis. The image sensor  42  supplies the electrical signal of each pixel of the image to the image processing unit  43 , and thus the image data is supplied to the compression processing unit  44  and the microcomputer  47 . 
     In Step S 26 , the microcomputer  47  displays an image based on the image data supplied from the image processing unit  43 , as a live-view image, on the display unit  50 . Further, the display control unit  74  superimposes a frame representing the in-focus area on the live-view image, for display on the display unit  50 . 
     In Step S 27 , the microcomputer  47  determines whether the release button  11  is full pressed or not, on the basis of the operation signal from the operation unit  52 . In Step S 27 , when it is determined that the release button  11  is full pressed, the processing proceeds to Step S 28 . 
     In Step S 28 , the compression processing unit  44  compresses the image data supplied from the image processing unit  43 . The compression processing unit  44  supplies the compressed image data to the medium control unit  45 . 
     In Step S 29 , the medium control unit  45  controls the recording medium  46  to record the compressed image data, which is supplied from the compression processing unit  44 , on the recording medium  46 , and proceeds the processing to Step S 30 . 
     Further, in Step S 21 , when it is determined that the release button  11  is not half pressed, the processing proceeds to Step S 30 . 
     In Step S 30 , the imaging apparatus  10  determines whether to terminate the processing or not, for example, whether the power button  11 A is operated or not. 
     In Step S 27 , when it is determined that the release button  11  is not full pressed, or in Step S 30 , when it is determined that the processing is not terminated, and when the in-focus area is other than the predetermined area, the area setting unit  73  sets the in-focus area for the face area. This enables the optical system  41  to be driven so as to bring the face area into focus. 
     On the other hand, when the in-focus area is the predetermined area, the area setting unit  73  leaves the in-focus area as the predetermined area. This enables the optical system  41  to be driven so as to bring the predetermined area into focus. The processing is then returned to Step S 11 , and the subsequent processing is repeated. At that time, in the case where the in-focus area is the predetermined area, a predetermined frame is superimposed on a live-view image to be displayed, in the processing of Step S 12 . 
     On the other hand, when it is determined in Step S 30  that the processing is terminated, the processing is terminated. 
       FIG.  12    is a flowchart for describing the face detection ON imaging processing that is imaging processing of the imaging apparatus  10  in the case where the face detection mode is the face detection ON mode. This face detection ON imaging processing is started when the power is turned on by operating the power button  11 A, for example. 
     Processing from Steps S 41  to S 43  of  FIG.  12    is similar to the processing from Steps S 11  to S 13  of  FIG.  11   , and thus description thereof will be omitted. 
     In Step S 44 , the display control unit  74  superimposes a temporary face frame of the face area supplied from the face detection unit  71  on a live-view image being displayed, for display on the display unit  50 . 
     Processing from Steps S 45  to S 49  is similar to the processing from Steps S 14  to S 18  of  FIG.  11   , and thus description thereof will be omitted. 
     In Step S 45 , when it is determined that the center button  23 E of the cross key  23  is not pressed, the processing proceeds to Step S 50 . In Step S 50 , the area setting unit  73  determines whether the release button  11  is half pressed or not, on the basis of the operation signal supplied from the operation unit  52 . 
     In Step S 50 , when it is determined that the release button  11  is half pressed, the processing proceeds to Step S 51 . Further, in Step S 47 , when it is determined that a pupil area is not detected, the processing proceeds to Step S 51 . 
     Processing from Steps S 51  to S 59  is similar to the processing of Steps S 19 , S 20 , and S 24  to S 30  of  FIG.  11   , and thus description thereof will be omitted. It should be noted that in the second and subsequent processing of Step S 44 , not a temporary face frame but a face frame is displayed. 
     It should be noted that the imaging processing of the imaging apparatus  10  in the case where the face detection mode is the registered face detection mode is similar to the face detection ON imaging processing except that matching between the acquired image data and the image data of the registered face image is performed in the processing of Step S 43 , though not shown in the figure. In the case where an area of the registered face image is detected by the matching, the area of the registered face image is set as the face area, and in the case where the area of the registered face image is not detected, an area of a face image other than the registered face image is set as the face area. 
     Further, the imaging processing of the imaging apparatus  10  in the case where the face detection mode is the smile shutter mode is similar to the face detection ON imaging processing except that the processing of Steps S 45  to S 49  is not performed. 
     As described above, since the center button  23 E functions as a selection unit that selects a pupil as a type of a subject serving as a focusing target in each imaging, the imaging apparatus  10  sets the in-focus area for the face area or the predetermined area until the center button  23 E is pressed after imaging is performed. 
     Further, in the case where a pupil is selected as a type of a subject serving as a focusing target in each imaging with use of the center button  23 E, the imaging apparatus  10  sets the pupil area as the in-focus area. Therefore, a pupil as a type of a subject serving as a focusing target can be easily set in each imaging. Further, a pupil as a type of a subject serving as a focusing target can be quickly set in each imaging. 
     Second Embodiment 
     (Configuration Example of Second Embodiment of Imaging Apparatus) 
       FIG.  13    is a block diagram showing a configuration example of an in-focus area control unit achieved by a microcomputer  47  of a second embodiment of the imaging apparatus  10  to which the present disclosure is applied. 
     The second embodiment of the imaging apparatus  10  is configured to be basically similar to the first embodiment except for the in-focus area control unit. Note that a half-press of the release button  11  functions as an instruction unit that gives an instruction of focusing. In other words, in the second embodiment of the imaging apparatus  10 , only a press of the center button  23 E of the cross key  23  does not perform focusing. After the center button  23 E is pressed and when the release button  11  is half pressed, focusing is performed. 
     In the configuration shown in  FIG.  13   , the same configurations as those of  FIG.  5    are denoted by the same reference numerals. Overlapping description will be appropriately omitted. 
     The configuration of an in-focus area control unit  130  of  FIG.  13    is different from the configuration of  FIG.  5    in that an area setting unit  131  is provided instead of the area setting unit  73 . 
     The area setting unit  131  of the in-focus area control unit  130  reads a face detection mode from the memory  51 . In the case where an operation signal representing a half-press of the release button  11  is supplied from the operation unit  52 , the area setting unit  131  sets a face area, a pupil area, or a predetermined area as an in-focus area in each imaging on the basis of the face detection mode. The area setting unit  131  supplies the in-focus area to the display control unit  74  and the focusing control unit  48  of  FIG.  4   . 
     (Description on Processing of Imaging Apparatus) 
     Imaging processing corresponding to the face detection mode according to the second embodiment of the imaging apparatus  10  is similar to that in the first embodiment except that when the center button  23 E is pressed, determination on whether the release button  11  is half pressed or not is performed before an optical system is driven. When it is determined that the release button  11  is half pressed, the optical system is driven so as to bring the in-focus area into focus, whereas when it is determined that the release button  11  is not half pressed, the optical system is not driven. 
     As described above, in the second embodiment of the imaging apparatus  10 , focusing can be achieved by a half-press of the release button  11  not by an in-focus area. Therefore, an operation by a user who is used to giving an instruction of focusing by half pressing the release button  11  can be made simple. 
     In contrast to this, in the first embodiment of the imaging apparatus  10 , one operation of pressing the center button  23 E enables selecting a type of a subject as a focusing target and giving an instruction of focusing. Therefore, an operation by a user can be made simple. 
     Third Embodiment 
     (Configuration Example of Third Embodiment of Imaging Apparatus) 
       FIG.  14    is a block diagram showing a configuration example of an in-focus area control unit achieved by a microcomputer  47  of a third embodiment of the imaging apparatus  10  to which the present disclosure is applied. 
     The third embodiment of the imaging apparatus  10  is configured to be basically similar to the first embodiment except for the in-focus area control unit. 
     Note that the upper button  23 A of the cross key  23  is pressed also when a flower is selected as a type of a subject as a focusing target in each imaging in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 . In other words, in the third embodiment of the imaging apparatus  10 , in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , the upper button  23 A functions as a selection unit that selects a flower as a type of a subject serving as a focusing target in each imaging. 
     In the configuration shown in  FIG.  14   , the same configurations as those of  FIG.  5    are denoted by the same reference numerals. Overlapping description will be appropriately omitted. 
     The configuration of an in-focus area control unit  150  of  FIG.  14    is different from the configuration of  FIG.  5    in that a flower detection unit  151  is newly provided and that an area setting unit  152  and a display control unit  153  are provided instead of the area setting unit  73  and the display control unit  74 . 
     The flower detection unit  151  of the in-focus area control unit  150  determines whether an operation signal representing a press of the upper button  23 A of the cross key  23  is supplied from the operation unit  52  or not, in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 . The flower detection unit  151  detects a flower area from the image data supplied from the image processing unit  43  on the basis of a determination result. The flower detection unit  151  supplies the flower area to the area setting unit  152 . 
     The area setting unit  152  reads the face detection mode from the memory  51 . The area setting unit  152  sets a face area, a pupil area, a flower area, or a predetermined area as an in-focus area in each imaging on the basis of the face detection mode and the operation signal representing a half-press of the release button  11  and being supplied from the operation unit  52 . The area setting unit  152  supplies the in-focus area to the display control unit  153  and the focusing control unit  48  of  FIG.  4   . 
     The display control unit  153  reads the face detection mode from the memory  51 . The display control unit  153  superimposes a face frame, which represents the face area supplied from the face detection unit  71 , on a live-view image being displayed, on the basis of the face detection mode, for display on the display unit  50 . Further, the display control unit  153  superimposes a frame, which represents the in-focus area supplied from the area setting unit  152 , on a live-view image being displayed, for display on the display unit  50 . 
     (Description on Processing of Imaging Apparatus) 
       FIG.  15    is a flowchart for describing face detection OFF imaging processing according to the third embodiment of the imaging apparatus  10 . This face detection OFF imaging processing is started when the power is turned on by operating the power button  11 A, for example. 
     Processing from Steps S 71  to S 80  of  FIG.  15    is similar to the processing from Steps S 11  to S 20  of  FIG.  11   , and thus description thereof will be omitted. 
     In Step S 74 , when it is determined that the center button  23 E is not pressed, the processing proceeds to Step S 81 . In Step S 81 , the flower detection unit  151  determines whether the upper button  23 A of the cross key  23  is pressed or not in a state where a menu screen or setting screen is not displayed on the liquid crystal monitor  26 , on the basis of the operation signal supplied from the operation unit  52 . 
     In Step S 81 , when it is determined that the upper button  23 A is pressed, the processing proceeds to Step S 82 , In Step S 82 , the flower detection unit  151  detects a flower area from the image data supplied from the image processing unit  43  and supplies the flower area to the area setting unit  152 . 
     In Step S 83 , the area setting unit  152  sets, as an in-focus area, the flower area supplied from the flower detection unit  151  and supplies the flower area to the display control unit  153  and the focusing control unit  48  of  FIG.  4   . 
     In Step S 84 , the display control unit  153  superimposes a flower frame, which represents the flower area, on a live-view image being displayed, on the basis of the flower area supplied from the area setting unit  152 , for display on the display unit  50 . The processing then proceeds to Step S 88 . 
     Processing from Steps S 85  to S 94  is similar to the processing from Steps S 21  to S 30  of  FIG.  11   , and thus description thereof will be omitted. 
       FIG.  16    is a flowchart for describing face detection ON imaging processing according to the third embodiment of the imaging apparatus  10 . This face detection ON imaging processing is started when the power is turned on by operating the power button  11 A, for example. 
     Processing from Steps S 111  to S 121  of  FIG.  16    is similar to the processing from Steps S 41  to S 49 , S 51 , and S 52  of  FIG.  12   , and thus description thereof will be omitted. 
     Processing from Steps S 122  to S 126  is similar to the processing from Steps S 81  to S 85  of  FIG.  15   , and thus description thereof will be omitted. 
     In Step S 126 , when it is determined that the release button  11  is half pressed, the processing proceeds to Step S 120 . On the other hand, in Step S 126 , when it is determined that the release button  11  is not half pressed, the processing proceeds to Step S 133 . 
     Processing from Steps S 127  to S 133  is similar to the processing from Steps S 24  to S 30  of  FIG.  11   , and thus description thereof will be omitted. 
     As described above, since the upper button  23 A functions as a selection unit that selects a flower as a type of a subject serving as a focusing target in each imaging, the imaging apparatus  10  sets the in-focus area for the face area or the predetermined area until the upper button  23 A is pressed after imaging is performed. 
     Further, in the third embodiment of the imaging apparatus  10 , in the case where a pupil is selected as a type of a subject serving as a focusing target in each imaging with use of the center button  23 A, a pupil area is set as the in-focus area. Additionally, in the third embodiment of the imaging apparatus  10 , in the case where a flower is selected as a type of a subject serving as a focusing target in each imaging with use of the upper button  23 A, a flower area is set as the in-focus area. Therefore, a pupil or a flower as a type of a subject serving as a focusing target can be easily set in each imaging. Further, a pupil or a flower as a type of a subject serving as a focusing target can be quickly set in each imaging. 
     It should be noted that also in the third embodiment of the imaging apparatus  10 , as in the second embodiment, focusing may be achieved by not only pressing the upper button  23 A and the center button  23 E but also half pressing the release button  11 . 
     Fourth Embodiment 
     (Description on Computer to which Present Disclosure is Applied) 
     The series of processing described above can be executed by hardware or software. In the case where the series of processing is executed by software, a program constituting the software is installed in a computer. Here, the computer includes a computer incorporated in dedicated hardware, a general-purpose personal computer that can execute various functions by installing various programs therein, and the like. 
       FIG.  17    is a block diagram showing a hardware configuration example of a computer that executes the series of processing described above by a program. 
     In a computer  200 , a CPU (Central Processing Unit)  201 , a ROM (Read Only Memory)  202 , and a RAM (Random Access Memory)  203  are connected to one another by a bus  204 . 
     Additionally, an input and output interface  205  is connected to the bus  204 . An imaging unit  206 , an input unit  207 , an output unit  208 , a storage unit  209 , a communication unit  210 , and a drive  211  are connected to the input and output interface  205 . 
     The imaging unit  206  is constituted by the optical system  41 , the image sensor  42 , the actuator  49 , the image processing unit  43 , and the like. The imaging unit  206  acquires image data by light from a subject. 
     The input unit  207  corresponds to the operation unit  52  and is constituted by a keyboard, a mouse, a microphone, and the like. The output unit  208  is constituted by a display, a speaker, and the like. The storage unit  209  is constituted by a hard disk, a nonvolatile memory, and the like. The communication unit  210  is constituted by a network interface and the like. The drive  211  drives a removable medium  212  such as a magnetic disc, an optical disc, a magneto-optical disc, a semiconductor memory, or the like. 
     In the computer  200  configured as described above, the series of processing described above is performed by the CPU  201  loading a program stored in the storage unit  209  to the RAM  203  via the input and output interface  205  and the bus  204  and executing the program, for example. 
     The program executed by the computer  200  (CPU  201 ) can be provided by, for example, being recorded on the removable medium  212  as a package medium or the like. Further, the program can be provided via a wired or wireless transmission medium such as a local area network, the Internet, or digital satellite broadcasting. 
     In the computer  200 , the program can be installed in the storage unit  209  via the input and output interface  205  by mounting the removable medium  212  to the drive  211 . Further, the program can be received in the communication unit  210  via a wired or wireless transmission medium and installed in the storage unit  209 . In addition, the program can be previously installed in the ROM  202  or the storage unit  209 . 
     It should be noted that the program executed by the computer  200  may be a program that is processed chronologically along the described order in this specification or may be a program that is processed in parallel or at a necessary timing such as when an invocation is performed. 
     The effects described herein are merely exemplary ones and are not restrictive ones, and any other effects may be produced. 
     Further, the embodiments of the present disclosure are not limited to the embodiments described above and can be variously modified without departing from the gist of the present disclosure. 
     For example, the type of the subject as a focusing target may be a type other than a pupil or a flower (for example, landscape, building, animal, household pet, and cooking). Further, the number of types of the subject as a focusing target can be set to three or more. 
     Additionally, the button functioning as the selection unit that selects a type of a subject as a focusing target in each imaging may be a button other than the cross key  23  (for example, the custom button  13 , the custom button  18 , the AEL button  21 , and the like). Note that a button functioning as a selection unit in each type of a subject differs. Further, the selection unit may be displayed on the liquid crystal monitor  26  and operated by the cross key  23 . In the case where the liquid crystal monitor  26  is configured by a touch panel, a selection unit on the liquid crystal monitor  26  is touched for operation. 
     Further, the type of the subject selected in each imaging may be not a type of a subject as a focusing target but a type of a subject as a photometry or colorimetry target for selecting optimum exposure, white balance, and the like. 
     Additionally, in the case where a pupil area can be detected without detecting a face area, it is possible to prevent a face area from being detected in the face detection OFF mode. Further, the imaging apparatus  10  may acquire not the phase difference information but contrast information and achieve focusing on the basis of the contrast information. 
     It should be noted that the present disclosure can also have the following configurations. 
     (1) An imaging apparatus, including: 
     an acquisition unit that acquires an image; 
     a first selection unit that selects a first type of a subject as a focusing target in each imaging of the image acquired by the acquisition unit; 
     a first detection unit that detects an area of the subject of the first type from the image in a case where the first type is selected by the first selection unit; and 
     an area setting unit that sets the area detected by the first detection unit as an in-focus area of the image. 
     (2) The imaging apparatus according to (1), further including a focusing control unit that controls the acquisition unit to come into focus in the in-focus area set by the area setting unit. 
     (3) The imaging apparatus according to (1), further including: 
     an instruction unit that gives an instruction of focusing; and 
     a focusing control unit that controls the acquisition unit to come into focus in the in-focus area set by the area setting unit, in a case where the instruction of focusing is given by the instruction unit. 
     (4) The imaging apparatus according to any one of (1) to (3), further including: 
     a second selection unit that selects a second type of a subject as a focusing target in each imaging of the image acquired by the acquisition unit; and 
     a second detection unit that detects an area of the subject of the second type from the image in a case where the second type is selected by the second selection unit, in which 
     the area setting unit sets the area detected by the second detection unit as an in-focus area of the image. 
     (5) An imaging method for an imaging apparatus, including: 
     an acquisition step of acquiring an image; 
     a first selection step of selecting a first type of a subject as a focusing target in each imaging of the image acquired by processing of the acquisition step; 
     a first detection step of detecting an area of the subject of the first type from the image in a case where the first type is selected by processing of the first selection step; and 
     an area setting step of setting the area detected by processing of the first detection step as an in-focus area of the image. 
     (6) A program causing a computer, which controls an imaging apparatus including an acquisition unit that acquires an image and a first selection unit that selects a first type of a subject as a focusing target in each imaging of the image acquired by the acquisition unit, to function as: 
     a first detection unit that detects an area of the subject of the first type from the image in a case where the first type is selected by the first selection unit; and 
     an area setting unit that sets the area detected by the first detection unit as an in-focus area of the image. 
     DESCRIPTION OF SYMBOLS 
     
         
           10  imaging apparatus 
           11  release button 
           23 A to  23 E button 
           42  image sensor 
           48  focusing control unit 
           72  pupil detection unit 
           73  area setting unit 
           151  flower detection unit 
           152  area setting unit