U.S. patent application number 13/451296 was filed with the patent office on 2012-08-09 for imaging apparatus and method for controlling the imaging apparatus.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Takeshi Sakaguchi.
Application Number | 20120200760 13/451296 |
Document ID | / |
Family ID | 41116579 |
Filed Date | 2012-08-09 |
United States Patent
Application |
20120200760 |
Kind Code |
A1 |
Sakaguchi; Takeshi |
August 9, 2012 |
IMAGING APPARATUS AND METHOD FOR CONTROLLING THE IMAGING
APPARATUS
Abstract
An imaging apparatus includes an image generation unit
configured to photoelectrically convert an object image formed by
an imaging optical system to generate an image, a control unit
configured to perform focusing control of the imaging optical
system, an object detecting unit configured to detect a plurality
of object regions based on the image generated by the image
generation unit, and a display unit configured to display the
plurality of object regions detected by the object detecting unit.
The object detecting unit sequentially detects the object regions
at a plurality of positions to which the imaging optical system is
moved, and the display unit juxtaposes and displays the object
regions detected by the object detecting unit with respect to the
image.
Inventors: |
Sakaguchi; Takeshi;
(Kawasaki-shi, JP) |
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
41116579 |
Appl. No.: |
13/451296 |
Filed: |
April 19, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12407254 |
Mar 19, 2009 |
8184192 |
|
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13451296 |
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Current U.S.
Class: |
348/333.05 ;
348/E5.045 |
Current CPC
Class: |
H04N 5/232127 20180801;
H04N 5/232945 20180801; H04N 5/232 20130101; H04N 5/23219 20130101;
H04N 5/23293 20130101; H04N 5/23218 20180801; H04N 5/23212
20130101 |
Class at
Publication: |
348/333.05 ;
348/E05.045 |
International
Class: |
H04N 5/232 20060101
H04N005/232 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 28, 2008 |
JP |
2008-088754 |
Claims
1. An imaging apparatus comprising: an image generation unit
configured to photoelectrically convert an object image formed by
an imaging optical system to generate an image; a control unit
configured to perform focusing control of the imaging optical
system; an object detecting unit configured to detect a plurality
of object regions based on the image generated by the image
generation unit; a display unit configured to display a plurality
of object region images representing the plurality of object
regions detected by the object detecting unit, wherein the
plurality of object region images differ from the image; and a
selection unit configured to select an object region image from
among the plurality of object region images, wherein the object
detecting unit detects the object regions at a plurality of
positions to which the imaging optical system is moved, and wherein
the control unit performs focusing control based on selection
result of the selection unit.
2. The imaging apparatus according to claim 1, wherein the display
unit displays the plurality of object region images with respect to
the image.
3. The imaging apparatus according to claim 1, wherein the display
unit juxtaposes and displays the plurality of object region images
with respect to the image.
4. The imaging apparatus according to claim 1, wherein the display
unit juxtaposes and displays the plurality of object region images
based on focal positions corresponding to the object regions.
5. The imaging apparatus according to claim 1, wherein the display
unit juxtaposes and displays the plurality of object region images
based on positions of the object regions in an image plane.
6. The imaging apparatus according to claim 1, wherein the display
unit juxtaposes and displays the plurality of object region images
based on a distance order of the object regions.
7. The imaging apparatus according to claim 1, wherein the
selection unit selects an object region image based on user's
instruction.
8. A method for controlling an imaging apparatus, the method
comprising: photoelectrically converting an object image formed by
an imaging optical system to generate an image; performing focusing
control of the imaging optical system; detecting a plurality of
object regions based on the generated image; displaying a plurality
of object region images representing the detected plurality of
object regions, wherein the plurality of object region images
differs from the image; selecting an object region image from among
the plurality of object region images, detecting the object regions
at a plurality of positions to which the imaging optical system is
moved; and performing focusing control based on result of
selecting.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser.
No. 12/407,254, filed Mar. 19, 2009, which claims priority from
Japanese Patent Application No. 2008-088754 filed Mar. 28, 2008,
which are hereby incorporated by reference herein in their
entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an imaging apparatus and a
method for controlling the imaging apparatus. More particularly,
the present invention relates to an imaging apparatus that detects
a face of an object using an image signal output from an image
sensor when a person is shot as the object, and also relates to a
method of controlling the imaging apparatus.
[0004] 2. Description of the Related Art
[0005] Conventionally, an autofocus (AF) camera of the
phase-difference detection type having a plurality of focus
detection points peforms focal position detection at each of the
plurality of focus detection points in a field. Then, the AF camera
performs control to focus on a focus detection point that is
automatically or intentionally selected from among the focus
detection points. In the automatic focus detection point selection,
a general camera selects and focuses on a focus detection point
having the shortest distance to an object based on the focus
detection results at the focus detection points.
[0006] Furthermore, there are AF cameras of the contrast type,
which captures an object image formed by an imaging lens using an
image sensor and determines an in-focus position using an image
signal obtained from a focus area. The camera of the contrast type
performs focusing on a focal position having a peak focus
evaluation value in the focus area.
[0007] In AF cameras of the contrast type, a camera that detects a
region of a face of a person and focuses on the face is known.
Regarding the face detection method, Japanese Patent Application
Laid-Open No. 8-63597 discusses a method for determining a face
candidate region corresponding to the shape of a face of a person
and determining a face region based on feature information of the
face candidate region. Further, Japanese Patent Application
Laid-Open No. 8-63597 discusses a method for detecting a face
candidate region by extracting an outline of a face of a person
from an image and a method for calculating a correlation value
between a plurality of templates of various shapes of faces and
detecting a face candidate region based on the correlation
value.
[0008] However, in the above-described AF focus detection methods,
it is difficult to perform focusing under a condition where the
depth of field becomes shallow with a camera to which a lens having
a long focal length is mounted. For example, when a plurality of
persons exist at different distances, a main object, on which a
photographer intends to focus, does not always exist within the
depth of field. In such a case, it is difficult to focus on the
main object.
[0009] In a camera of the phase-difference detection type, when
control is automatically performed to focus on a focus detection
point from among a plurality of focus detection points, if an
unexpected object exists near the focus detection point, the
unexpected object may be focused. Accordingly, in the camera of the
phase-difference detection type, it is difficult to focus on a main
object a photographer intends to shoot.
[0010] Moreover, in the camera of the contrast type, focusing is
performed such that an object having a maximum peak contrast is to
be focused. Accordingly, for example, when a peak of the contrast
of a background is larger than that of a main object, the
background may be focused. Further, for example, when a peak of the
contrast of clothes is larger than that of the face of the object,
the clothes may be focused. As described above, in a camera of the
contrast type, the position of focus to be detected is unstable,
and it is difficult to focus on a point a photographer intends to
focus.
[0011] In a camera of the face detection type that detects a face
of an object and focus on the face, it is possible to detect a face
of an object existing within the depth of field. However, if a main
object does not exist within the depth of field, it is difficult to
find the main object.
[0012] To solve the drawbacks described above, Japanese Patent
Application Laid-Open No. 2006-345254 discusses a method for
detecting faces of a plurality of objects and grouping the faces
based on shooting parameters, such as object distances and object
luminance values of the faces. In the method discussed in Japanese
Patent Application Laid-Open No. 2006-345254, by setting optimum
shooting parameters for each group, it is possible to perform
shooting with the optimum shooting parameters for each object.
[0013] However, under a condition where the depth of field of a
camera is shallow, if a plurality of persons exist at different
distances, it is difficult to focus on a main object a photographer
intends to focus.
[0014] When a main object does not exist within the depth of field
at the current focal position, it is necessary to focus on the main
object within the depth of field at another focal position by
driving a focusing lens. In such a case, if a camera of the
phase-difference detection type is used, a closest object is
focused. If a camera of the contrast type is used, a point having
the highest peak of contrast is focused. However, in both cases,
the focused points are not always a main object.
[0015] There is a method for detecting faces of a plurality of
objects, grouping the faces based on shooting parameters, such as
object distances and object luminance values of the faces, setting
shooting parameters optimum for each group, and performing
shooting. In the method, with a single release operation, shooting
is performed at a plurality of focal points where the faces of the
objects are detected. Accordingly, it is possible to perform
shooting on a plurality of persons within an image plane.
[0016] In the method described above, an image of the well focused
main object can be recorded. However, it is necessary to record the
other images. Accordingly, unnecessary images are recorded, and it
takes a lot of time to organize the shot images. Further, in this
method, when a plurality of persons exist within an image plane, it
is not possible to record an image with only a main object
focused.
SUMMARY OF THE INVENTION
[0017] The present invention is directed to an imaging apparatus
that detects, for example, faces of objects, and focuses on the
objects, and displays the objects of which detection of object
regions are established as a list. Further, the present invention
is directed to an imaging apparatus that can select an object to
focus on as a main object and focus on the selected object.
[0018] According to an aspect of the present invention, an imaging
apparatus includes an image generation unit configured to
photoelectrically convert an object image formed by an imaging
optical system to generate an image, a control unit configured to
perform focusing control of the imaging optical system, an object
detecting unit configured to detect a plurality of object regions
based on the image generated by the image generation unit, and a
display unit configured to display the plurality of object regions
detected by the object detecting unit. The object detecting unit
sequentially detects the object regions at a plurality of positions
to which the imaging optical system is moved, and the display unit
juxtaposes and displays the object regions detected by the object
detecting unit with respect to the image.
[0019] Further features and aspects of the present invention will
become apparent from the following detailed description of
exemplary embodiments with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate exemplary
embodiments, features, and aspects of the invention and, together
with the description, serve to explain the principles of the
invention.
[0021] FIG. 1 is a block diagram illustrating a camera according to
an exemplary embodiment of the present invention.
[0022] FIG. 2 is a flowchart illustrating imaging processing
performed by the camera according to an exemplary embodiment of the
present invention.
[0023] FIG. 3 is a flowchart illustrating face search processing
according to an exemplary embodiment of the present invention.
[0024] FIG. 4 is a flowchart illustrating face list displaying
processing according to an exemplary embodiment of the present
invention.
[0025] FIG. 5 illustrates a first display format of a face list in
a display device according to an exemplary embodiment of the
present invention.
[0026] FIG. 6 illustrates a second display format of the face list
in the display device according to an exemplary embodiment of the
present invention.
[0027] FIG. 7 illustrates a third display format of the face list
in the display device according to an exemplary embodiment of the
present invention.
[0028] FIG. 8 illustrates a fourth display format of the face list
in the display device according to an exemplary embodiment of the
present invention.
[0029] FIG. 9 illustrates a fifth display format of the face list
in the display device according to an exemplary embodiment of the
present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0030] Various exemplary embodiments, features, and aspects of the
invention will be described in detail below with reference to the
drawings.
[0031] FIG. 1 is a block diagram illustrating a camera (imaging
apparatus) 100 according to an exemplary embodiment of the present
invention.
[0032] Referring to FIG. 1, the camera 100 includes an imaging
optical system (imaging lens) 101 and an image sensor 107 having a
plurality of pixels. The image sensor 107 includes a charge-coupled
device (CCD), a complementary metal-oxide semiconductor (CMOS)
sensor, or the like, on which an optical image of an object is
formed by the imaging optical system 101. The image sensor 107
photoelectrically converts the object image formed by the imaging
optical system 101 and outputs an image signal.
[0033] A main mirror 102, which has a semi-transmissive section,
moves to the outside of an imaging light flux during shooting, and
is obliquely disposed in the imaging light flux (on an optical
path) during focus detection. FIG. 1 illustrates a state (mirror
down) in which the main mirror 102 is inserted into the imaging
light flux. In a state in which the main mirror 102 is obliquely
disposed in the imaging light flux, the main mirror 102 guides a
part of light flux that is transmitted through the imaging optical
system 101 to a finder optical system, which includes a focusing
screen 103, a pentagonal prism 104, and an eyepiece lens 105.
[0034] A sub mirror 106 can be folded or extended relative to the
main mirror 102 in synchronization with operation of the main
mirror 102. A part of the light flux transmitted through the
semi-transmissive section of the main mirror 102 is reflected
downward by the sub mirror 106 and enters a focus detection device
108 of the phase-difference type. Thus, a focusing state of the
imaging optical system 101 can be detected.
[0035] In cameras of the contrast type, the main mirror 102 is
always moved to the outside of the imaging light flux. In
synchronization with the operation, in a state in which the sub
mirror 106 is folded relative to the main mirror 102 (mirror up),
an object optical image transmitted through the imaging optical
system 101 is formed on the image sensor 107. Thus, a focusing
state of the imaging optical system 101 can be detected.
[0036] An analog signal processing circuit 109 performs processing,
such as denoising processing, on an image signal output from the
image sensor 107 based on the light quantity of an object optical
image formed by the imaging optical system 101. An
analog-to-digital (A/D) converter 110 converts the analog signal
output from the analog signal processing circuit 109 into a digital
signal.
[0037] A digital signal processing circuit 111, which is connected
to a system controller 112 (described below), performs image
processing, such as shading correction or gamma correction, on the
digital signal output from the A/D converter 110.
[0038] The above-described image sensor 107, the analog signal
processing circuit 109, the A/D converter 110, and the digital
signal processing circuit 111 constitute an image generation unit
130. The image generation unit 130 photoelectrically converts an
object image formed by the imaging optical system 101 to generate
an image.
[0039] The system controller 112 includes a central processing unit
(CPU) for performing overall control of the camera 100, and a
storage device (storage unit), such as a random access memory
(RAM). The system controller 112 appropriately controls operation
of various parts, such as a lens driving device 113 (described
below). The storage device in the system controller 112, as will be
described below, stores focal positions and image locations of a
plurality of object regions detected by a an object detection unit,
such as a face detection circuit 121.
[0040] The lens driving device (lens driving unit) 113 is connected
to the system controller 112. The lens driving device 113 includes
a communication circuit that communicates with the imaging optical
system 101, a lens driving mechanism that drives the imaging
optical system 101 to adjust focus, and a driving circuit that
drives the driving mechanism.
[0041] The system controller 112 and the lens driving device 113
constitute a control unit 140. As will be described below, the
control unit 140 performs focusing control of the imaging optical
system 101.
[0042] A mirror driving device 114, which is connected to the
system controller 112, drives the main mirror 102 to the outside of
the imaging light flux. An image sensor driving device 115, which
is connected to the system controller 112, drives the image sensor
107.
[0043] A buffer memory 116, which is connected to the digital
signal processing circuit 111, functions as a frame memory that can
store data of a plurality of frames captured by the image sensor
107. A digital signal output from the A/D converter 110 is
temporarily stored in the buffer memory 116. The digital signal
processing circuit 111 reads the data stored in the buffer memory
116, and performs the above-described processing. The data
processed by the digital signal processing circuit 111 is stored in
the buffer memory 116.
[0044] A recording/reproducing signal processing circuit 117 is
connected to the digital signal processing circuit 111. As
described above, the image data on which various digital processing
is performed in the digital signal processing circuit 111 is stored
in the buffer memory 116. The recording/reproducing signal
processing circuit 117, after the processing, records the image
data stored in the buffer memory 116 on an external storage medium
118, such as a memory card.
[0045] In recording the image data on the external storage medium
118, image data compression is performed, for example, in
accordance with Joint Photographic Experts Group (JPEG) format. In
reading the image data from the external storage medium 118, the
recording/reproducing signal processing circuit 117 performs
decompression processing on the image data. The
recording/reproducing signal processing circuit 117 includes an
interface for performing data communication between the
recording/reproducing signal processing circuit 117 and the
external storage medium 118.
[0046] A display device (display unit) 120 displays an image
captured by the image sensor 107. The display device 120 is also
used to reproduce and display the image data recorded on the
external storage medium 118. To display an image on the display
device 120, the image data stored in the buffer memory 116 is read.
The read image data is converted from digital image data into an
analog video signal by a digital-to-analog converter (D/A
converter) 119. The display device 120 displays the image using the
analog video signal converted by the D/A converter 119. As will be
described below, the display device 120 displays a plurality of
object regions detected by the face detection circuit 121.
[0047] In displaying an image captured by the image sensor 107 on
the display device 120, two types of display formats are provided.
One format is a display format used when a release operation is not
performed. The display format is referred to as a through-image. In
the display format, an image repeatedly captured by the image
sensor 107 is sequentially updated and displayed. The other format
is referred to as a freeze image. In the freeze image format, after
a release operation of the camera 100 is performed, an image
captured by the image sensor 107 is displayed for a predetermined
period of time.
[0048] The face detection circuit (object detection unit) 121 is
connected to the digital signal processing circuit 111. The face
detection circuit 121 detects whether a face (object region) is
contained in the image data on which various digital processing is
performed by the digital signal processing circuit 111. As
described above, based on the image generated by the image
generation unit 130, the face detection circuit 121 detects a
plurality of object regions. Regarding the face detection method,
for example, Japanese Patent Application Laid-Open No. 8-63597
discusses it.
[0049] An operation unit (instruction unit) 122 is connected to the
system controller 112. The operation unit 122 includes operation
members used to operate the camera 100. The operation members
include a power supply switch for turning on or off a power source
of the camera 100, a release button, and a setting button for
selecting a shooting mode, such as a person shooting mode. By
operating the switches or buttons, a signal corresponding to the
operation is input to the system controller 112. As will be
described below, the operation unit 122 is used to select one of a
plurality of object regions displayed on the display device 120.
Then, the system controller 112 performs focusing control on the
object region selected by the operation unit 122.
[0050] A release switch SW1, which is operable by the photographer
to be turned on by a first stroke operation (half press operation)
of the release button, and a release switch SW2, which is operable
by the photographer to be turned on by a second stroke operation
(full press operation) of the release button are connected to the
release button.
[0051] Next, imaging processing performed by the camera 100
according to an exemplary embodiment of the present invention is
described.
[0052] FIG. 2 is a flowchart illustrating imaging processing
performed by the camera according to an exemplary embodiment of the
present invention. In the imaging processing according to the
exemplary embodiment of the present invention, shooting is
performed by detecting and recognizing faces of objects and
focusing on a face of a main object.
[0053] In step S101, the system controller 112 determines whether
the release switch SW1, which is apart of the operation unit 122,
is pressed. If the release switch SW1 is not pressed (NO in step
S101), the processing in step S101 is repeated until the release
switch SW1 is pressed. On the other hand, if the release switch SW1
is pressed (YES in step S101), the processing proceeds to step
S102.
[0054] In step S102, the system controller 112 communicates with
the imaging optical system 101 via the lens driving device 113, and
drives the imaging optical system 101 within an entire drive range
of the imaging optical system 101. With such control, the face
detection circuit 121 can detect, in a plurality of focal
positions, faces of objects in the image data on which various
processing is performed by the digital signal processing circuit
111. The face search processing is described below.
[0055] Step S102 includes an image generation step for
photoelectrically converting an object image formed by the imaging
optical system 101 to generate an image, and a detection step for
detecting a plurality of object regions based on the image
generated in the image generation step.
[0056] In step S103, the system controller 112 determines whether
face detection is established as a result of the face search
processing in step S102. If the face detection is not established
(NO in step S103), the imaging processing ends. On the other hand,
if the face detection is established (YES in step S103), the
processing proceeds to step S104.
[0057] In step S104, the system controller 112 generates a list of
a plurality of faces of which the detection is established in step
S102. The generated list of faces is displayed on the display
device 120 via the digital signal processing circuit 111. As
described above, step S104 includes a displaying step for
displaying a plurality of object regions detected in step S102. The
displaying step will be described in detail below.
[0058] In step S105, the system controller 112 determines whether a
face on which the photographer intends to focus as a main object is
selected from the list of faces displayed on the display device 120
in step S104 using the operation unit 122. The determination is
performed by the system controller 112. If the selection of a face
by the photographer is not performed (NO in step S105), the
processing returns to step S101, and the above processing is
repeated. On the other hand, if the intended face is selected by
the photographer (YES in step S105), the processing proceeds to
step S106.
[0059] In step S106, the system controller 112 drives the imaging
optical system 101 via the lens driving device 113 to the focal
position where the detection of the face selected in step S105 is
established. As described above, step S106 includes a control step
for performing focusing control on the selected object region by,
in step S105, selecting one of a plurality of object regions
displayed in step S104.
[0060] In step S106, the lens driving device 113 drives the imaging
optical system 101 to the focal position of the object region
selected using the operation unit 122. The operation is performed
by the system controller 112 reading the focal position of the
object region selected using the operation unit 122 from the
storage device (storage unit) in the system controller 112, as
described in further detail below. The lens driving device 113
(control unit 140) performs focusing control based on the focal
position of the object region read from the storage device.
[0061] After the control, the face detection processing can be
performed once again, or the processing can directly proceed to
step S107.
[0062] In step S107, the system controller 112 determines whether
the release switch SW2, which is a part of the operation unit 122,
is pressed. If the release switch SW2 is not pressed (NO in step
S107), the processing returns to step S101, and the above
processing is repeated. On the other hand, if the release switch
SW2 is pressed (YES in step S107), the processing proceeds to step
S108.
[0063] In step S108, the system controller 112 performs shooting
and stores the shot image.
[0064] Next, the face search processing performed in step S102 in
FIG. 2 is described in detail. FIG. 3 is a flowchart illustrating
the face search processing performed in step S102.
[0065] In step S201, the system controller 112 determines whether
the face search processing is performed within the entire drive
range of the mounted imaging optical system 101 via the lens
driving device 113. If the face search processing is performed
within the entire drive range of the imaging optical system 101
(YES in step S201), the face search processing ends. On the other
hand, if the face search processing is not performed within the
entire drive range of the imaging optical system 101 (NO in step
S201), the processing proceeds to step S202.
[0066] In step S202, the system controller 112 writes an image
signal output from the image sensor 107 as image data into the
buffer memory 116 via the A/D converter 110 and the digital signal
processing circuit 111.
[0067] In step S203, based on the image data written into the
buffer memory 116 in step S202, the face detection circuit 121
performs the face search processing (face recognition
processing).
[0068] In step S204, the system controller 112 determines whether
the face recognition processing is established in step S203. If the
face recognition processing is not established (NO in step S204),
the processing proceeds to step S206. On the other hand, if the
face recognition processing is established (YES in step S204), the
processing proceeds to step S205.
[0069] In step S205, the system controller 112 stores the faces,
the focal positions, and the image locations at the time of
establishment of the face recognition processing in step S203 into
the storage device in the system controller 112. As described
above, the system controller 112 stores the focal positions and
image locations of a plurality of object regions detected by the
face detection circuit 121.
[0070] In step S206, the system controller 112 performs focal
position adjustment via the lens driving device 113, which drives
the imaging optical system 101. After the focal position adjustment
is completed, the processing returns to step S201. Then, the
processing from step S201 to step S206 is repeated until the face
search processing within the entire drive range of the imaging
optical system 101 is completed.
[0071] Next, the face list displaying processing performed in step
S104 in FIG. 2 is described in detail. FIG. 4 is a flowchart
illustrating the face list displaying processing performed in step
S104.
[0072] In step S301, the system controller 112 determines whether
the face recognition is established in the face search processing
in the step S102. If the face recognition is not established (NO in
step S301), the processing proceeds to step S304. In step S304, the
system controller 112 notifies the photographer that the face
recognition is not established. On the other hand, if the face
recognition is established (YES in step S301), the processing
proceeds to step S302.
[0073] In step S302, the digital signal processing circuit 111 in
the image generation unit 130 sorts the faces recognized in step
S301. The sorting can be performed, for example, in order of
distance, or in order of image location. In performing the sorting
of the faces, information about the focal positions or the image
locations of a plurality of faces detected by the face detection
circuit 121 is read from the storage device provided in the system
controller 112 in the control unit 140. Based on the information,
the digital signal processing circuit 111 performs the sorting
processing.
[0074] When the sorting processing is performed according to the
distance order, for example, the faces can be juxtaposed from the
nearest face to the farthest face. When the sorting processing is
performed according to the order of image location, for example,
the faces can be juxtaposed in the direction from a central part to
a peripheral part of the image plane, in the direction from the
left to the right of the image plane, or in the clockwise
direction. The faces can also be juxtaposed with a combination of
the above-described directions. Further, the faces can be displayed
without sorting the faces, for example, in order of the established
face detection or at random.
[0075] In step S303, the system controller 112 displays the list of
the faces generated in step S302 on the display device 120. More
specifically, the image generation unit 130 instructs the display
device 120 to display the plurality of object regions based on the
information about the plurality of object regions detected by the
face detection circuit 121. Examples of the display are illustrated
in FIGS. 5 to 7. FIGS. 5 to 7 illustrate display formats of the
face list on the display device 120 according to an exemplary
embodiment of the present invention.
[0076] As illustrated in FIG. 5, as a display format of the face
list, a first display format that displays an image 201 in live
view and a face list 202 can be employed. In the display format,
corresponding to objects A to H in the image 201 in live view,
faces a to h of the objects are displayed, respectively.
[0077] In the first display format of the face list in FIG. 5, the
face list 202 (faces a to h) is sorted in distance order in step
S302. Then, the faces are juxtaposed from the object A that exists
at a short distance to the object H that exists at a far distance,
and in the order left to right. The faces displayed in the face
list 202 can be displayed at the original size of the object region
stored in the storage device in the system controller 112 in the
face search processing, or can be displayed by enlarging or
reducing to a predetermined size.
[0078] The image 201 in live view is displayed by focusing on the
object A that is the nearest object in the face list 202. The image
201 in live view can be focused on the nearest object A until the
photographer displays the face list 202 and selects a face to
focus. Alternatively, an image that is focused in the order from
the object A to the object H for every predetermined period of time
can be displayed.
[0079] As a display format of the face list, as illustrated in FIG.
6, a second display format that displays only an object face list
(faces a to h) 203 can be employed. Further, as illustrated in FIG.
7, a third display format that displays an image 204 by combining
an image in live view with faces on which face detection is
established can be employed. Also in the third display format,
corresponding to the objects A to H, the faces a to h are
displayed, respectively. The display formats of the face list can
be changed by the photographer operating the operation unit
122.
[0080] FIG. 8 illustrates a fourth display format of the face list
on the display device 120 according to an exemplary embodiment of
the present invention. FIG. 8 illustrates a scene in which objects
I, J, and K exist at the same distance from the camera. It is
assumed that the objects I, J, and K exist within the depth of
field at the same focal position.
[0081] In an image 301 in live view, an image of the objects I, J,
and K that are in an in-focus state is displayed. In a face list
302, faces i, j, and k of the objects I, J, and K, respectively, of
which face detection is established are displayed in the order of
image location (counterclockwise from a central part to a
peripheral part of the image plane).
[0082] FIG. 9 illustrates a fifth display format of the face list
on the display device 120 according to an exemplary embodiment of
the present invention. Similar to FIG. 8, FIG. 9 illustrates a
scene in which objects I, J, and K exist at the same distance from
the camera.
[0083] If the objects I, J, and K exist within the depth of field
at the same focal position, the objects I, J, and K can be grouped
as an object L such that the image is displayed as an image 401 in
live view in FIG. 9. In a face list 402, a face 1 that is a
representative of the group L can be displayed. In the processing,
as the face 1, for example, a face at the center of the image plane
is selected in the order of image location. The grouping can be
performed by operating the operation unit 122 by the photographer
or can be automatically performed based on the number of objects in
the image plane. As described above, when the face detection
circuit 121 detects a plurality of object regions within the depth
of field, the system controller 112 (image generation unit 130)
groups the plurality of object regions and displays the
representative object region on the display device 120.
[0084] As described above, in an imaging apparatus according to an
exemplary embodiment of the present invention, by selecting a face
of an object a photographer intends to focus as a main object from
a displayed list of faces of which the face detection is
established, focusing control can be performed on the main object.
Accordingly, the imaging apparatus can perform focusing control on
a main object selected by a photographer.
[0085] In the above descriptions, the object the photographer
intends to focus is described as a person, and the region for the
focal position adjustment is described as the region of which the
face detection is performed. However, an exemplary embodiment of
the present invention is not limited to the above. For example, an
object image can be clipped from a background to perform object
detection. Then, a region corresponding to the object position can
be set as an object region for focal position detection.
[0086] While the present invention has been described with
reference to the exemplary embodiment, it is to be understood that
the invention is not limited to the disclosed exemplary embodiment.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all modifications, equivalent
structures, and functions.
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