U.S. patent application number 15/255895 was filed with the patent office on 2016-12-22 for imaging device for capturing self-portrait images.
The applicant listed for this patent is Intellectual Ventures Fund 83 LLC. Invention is credited to John R. Fredlund, Robert M. Guidash, Kenneth A. Parulski, Frank Razavi, Kevin E. Spaulding.
Application Number | 20160373646 15/255895 |
Document ID | / |
Family ID | 43858189 |
Filed Date | 2016-12-22 |
United States Patent
Application |
20160373646 |
Kind Code |
A1 |
Fredlund; John R. ; et
al. |
December 22, 2016 |
IMAGING DEVICE FOR CAPTURING SELF-PORTRAIT IMAGES
Abstract
A digital camera for capturing an image containing the
photographer, comprising: an image sensor; an optical system for
forming an image of a scene on the image sensor; a processor for
processing the output of the image sensor in order to detect the
presence of one or more faces in a field of view of the digital
camera; a feedback mechanism for providing feedback to the
photographer while the photographer is included within the field of
view, responsive to detecting at least one face in the field of
view, and a means for initiating capture of a digital image of the
scene containing the photographer.
Inventors: |
Fredlund; John R.;
(Rochester, NY) ; Parulski; Kenneth A.;
(Rochester, NY) ; Guidash; Robert M.; (Rochester,
NY) ; Spaulding; Kevin E.; (Spencerport, NY) ;
Razavi; Frank; (Fairport, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intellectual Ventures Fund 83 LLC |
Las Vegas |
NV |
US |
|
|
Family ID: |
43858189 |
Appl. No.: |
15/255895 |
Filed: |
September 2, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14584175 |
Dec 29, 2014 |
9462181 |
|
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15255895 |
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|
|
12716304 |
Mar 3, 2010 |
8957981 |
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14584175 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/012 20130101;
H04N 5/232 20130101; G01S 3/7864 20130101; H04N 1/00488 20130101;
H04N 5/23293 20130101; G06F 21/32 20130101; H04N 1/0049 20130101;
H04N 2101/00 20130101; G06F 3/0304 20130101; H04N 5/232939
20180801; H04N 1/0035 20130101; H04N 1/00514 20130101; H04N
5/232933 20180801; G06F 21/83 20130101; H04N 5/23218 20180801; H04N
5/23219 20130101; G06F 3/016 20130101; H04N 5/23216 20130101; G06F
3/017 20130101 |
International
Class: |
H04N 5/232 20060101
H04N005/232; G01S 3/786 20060101 G01S003/786; G06T 7/00 20060101
G06T007/00 |
Claims
1. A device comprising: an image sensor, wherein the device is
configured to capture images; a processor configured to process an
output of the image sensor in order to detect a presence of one or
more faces in a field of view of the device; and a feedback
mechanism configured to provide feedback responsive to detecting a
face in the field of view, wherein the feedback mechanism provides
information about the number of faces in the field of view of the
device.
2. The device of claim 1, wherein the feedback mechanism provides
an alert relating to the information about the number of faces in
the field of view of the device.
3. The device of claim 1, wherein the feedback mechanism initiates
an image capture when predetermined criteria is satisfied relating
to the information about the number of aces in the field of view of
the device.
4. The device of claim 1, wherein the feedback mechanism only
provides feedback during a self-portrait mode of the device.
5. The device of claim 4, wherein the feedback mechanism provides
feedback in response to a distance between the device and the
detected face being within a specified range of distances.
6. The device of claim 5, wherein the distance is provided by a
calibration process for the self-portrait mode.
7. The device of claim 5, wherein the specified range of distances
comprises a stored range of distances at which a photographer can
hold the device at arm's length.
8. The device of claim 4, wherein the self-portrait mode is
activated when the detected face comprises a face that was
previously registered by the calibration process.
9. The device of claim 1, wherein the processor applies different
composition rules depending on a number of faces detected within
the field of view.
10. The device of claim 9, wherein the composition rule is to
center the faces within the field of view.
11. A method comprising: processing, by a processor, an output of
an image sensor of a device configured to capture images in order
to detect a presence of one or more faces in a field of view of the
device; and providing feedback, by a feedback mechanism, responsive
to detecting a face in the field of view, wherein the feedback
mechanism provides feedback about how many faces are in the field
of view of the device.
12. The method of claim 11, further comprising providing an alert
relating to how many faces are in the field of view of the
device.
13. The method of claim 11, further comprising calibrating the
device, including providing the processor with a distance between
the device and the detected face being within a specified range of
distances.
14. The method of claim 9, further comprising applying different
composition rules depending on a number of faces detected within
the field of view.
15. A non-transitory computer-readable medium having instructions
stored thereon that, upon execution, cause a computer device to
perform operations comprising: processing an output of an image
sensor of a device configured to capture images in order to detect
a presence of one or more faces in a field of view of the device;
and providing feedback in response to detecting at least one face
in the field of view of the device.
16. The non-transitory computer-readable medium of claim 15,
wherein the operations further comprise initiating an image capture
when predetermined criteria is satisfied relating to the
information about the number of aces in the field of view of the
device.
17. The non-transitory computer-readable medium of claim 15,
further comprising calibrating the device, including providing the
processor with a distance between the device and the detected face
being within a specified range of distances.
18. The non-transitory computer-readable medium of claim 17,
further comprising activating a self-portrait mode when the
detected face comprises a face that was previously registered by
the calibration process.
19. The non-transitory computer-readable medium of claim 17,
wherein the specified range of distances comprises a stored range
of distances at which a photographer can hold the device at arm's
length.
20. The non-transitory computer-readable medium of claim 15,
further comprising applying different composition rules depending
on a number of faces detected within the field of view.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a Continuation of U.S. application Ser.
No. 14/584175, filed Dec. 29, 2014, which is a Continuation of U.S.
application Ser. No. 12/716304, filed Mar. 3, 2010, incorporated
herein by reference in its entirety.
FIELD
[0002] This disclosure pertains to the field of capturing digital
images with a portable digital capture device, and more
particularly to a digital capture device having modes providing
improved usability when held at arm's length to capture images
containing the user.
BACKGROUND
[0003] Digital cameras have become very common and have largely
replaced traditional film cameras. Today, most digital cameras
incorporate an image display screen on the back of the camera. The
display screen enables images to be composed as they are being
captured, and provides user interface elements for adjusting camera
settings. The display screen is also used to browse through images
that have been captured and are stored in the digital camera's
memory. However, due to the position of the display on the back of
the camera, the user does not receive any visual feedback when the
user wishes to be in the field of capture of the camera.
[0004] A user often desires to capture a photo of himself at a
particular venue. This can be accomplished by holding the camera at
arm's length and guessing if the camera is pointed in such a manner
that the user's face will be in the captured image. This is
difficult for many users, and multiple captures are often made to
provide a single acceptable one.
[0005] Another technique is to use the timer mode of the camera.
This requires that the camera be placed on a tripod or rigid
surface, and the user must scurry from the camera to the field of
capture within the time allotted. Most users are unwilling to carry
a tripod, and often finding a good surface for placement of the
camera is difficult. Additionally, the camera may move when the
shutter button is pressed, and since there is no verification that
the user is in the field of view of the camera, the image may need
to be captured multiple times for the user to be properly captured.
There is also the issue of allowing the camera to be placed at a
distance from the user when the image is captured. This may be
undesirable in crowded venues where theft is a possibility.
[0006] At times, other people may offer or be solicited to capture
the image of the user. In addition to concerns about theft, the
lack of control over image capture abilities and techniques of the
other person may produce images that are not acceptable to the
user.
[0007] Cameras sometimes incorporate mirrors to provide visual
feedback. However, these can be difficult to see due to small size,
or may be inconveniently located. These mirrors also add material
and assembly cost, and cannot provide proper results when optical
or digital zooming is used. The Palm Pre cell phone has such a
mirror that can be deployed by sliding the backward facing display
upward.
[0008] Cameras can also use a framing apparatus, as described in
commonly assigned U.S. Pat. No. 5,565,947. This patent describes
how a plurality of thin elements can be arrayed on the front
surface of the camera around the lens in general correspondence
with the field of view. Framing accuracy is improved for self
portraits by canting each element outwardly from the optical axis
at such an angle that an inside surface of every element is visible
to a subject positioned within the field of view of the lens. Like
mirrors, this thin framing element also add material and assembly
cost, and cannot provide proper results when optical or digital
zooming is used.
[0009] Some cameras, such as the Samsung DualView TL220, have
provided an additional display on the front of the camera that the
user can view while composing the image. While this is an
improvement, it adds significant cost to the camera due to the need
to incorporate two displays. Additionally, the image is small and
can be difficult to see.
[0010] Some cameras, such as the Casio EX-P505, have an
articulating display that can be repositioned such that the user
can view the scene that is being captured. Unfortunately,
arrangements of this type add significant cost and, are also
fragile since the display is not safely contained within the
confines of the camera body.
[0011] There remains a need for a cost effective and user-friendly
method for improving the ability for a user to compose and capture
a self portrait while holding a camera.
SUMMARY
[0012] The present invention represents a digital camera for
capturing an image containing the photographer, comprising:
[0013] an image sensor;
[0014] an optical system for forming an image of a scene on the
image sensor;
[0015] a processor for processing the output of the image sensor in
order to detect the presence of one or more faces in a field of
view of the digital camera;
[0016] a feedback mechanism for providing feedback to the
photographer while the photographer is included within the field of
view, responsive to detecting at least one face in the field of
view, and
[0017] a means for initiating capture of a digital image of the
scene containing the photographer.
[0018] whether the camera is correctly oriented when it is held at
arms length for capturing an image containing the photographer.
[0019] It has the additional advantage that it is lower in cost and
complexity than alternate solutions which require a second display,
or a repositionable display.
[0020] It has the further advantage that the photographer can
maintain possession of the camera during the process of capturing
an image containing the photographer, thus providing added
protection against theft and greater control over the photographic
process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a high-level diagram showing the components of a
digital camera system;
[0022] FIG. 2 is a flow diagram depicting typical image processing
operations used to process digital images in a digital camera;
[0023] FIG. 3 illustrates a self-portrait photography scenario
according to the present invention;
[0024] FIG. 4 is a diagram illustrating one embodiment of a digital
camera for implementing the present invention;
[0025] FIG. 5 is a flowchart showing steps for providing user
feedback according to the present invention;
[0026] FIG. 6 is a flowchart showing additional details for the
determine feedback step of FIG. 5 according to one embodiment of
the present invention;
[0027] FIG. 7 illustrates example preferred face zones that are
useful for applying composition rules; and
[0028] FIG. 8 is a diagram illustrating an alternate embodiment of
a digital camera for implementing the present invention using
multiple signal lights.
[0029] It is to be understood that the attached drawings are for
purposes of illustrating the concepts of the invention and may not
be to scale.
DETAILED DESCRIPTION
[0030] In the following description, a preferred embodiment of the
present invention will be described in terms that would ordinarily
be implemented as a software program. Those skilled in the art will
readily recognize that the equivalent of such software can also be
constructed in hardware. Because image manipulation algorithms and
systems are well known, the present description will be directed in
particular to algorithms and systems forming part of, or
cooperating more directly with, the system and method in accordance
with the present invention. Other aspects of such algorithms and
systems, and hardware or software for producing and otherwise
processing the image signals involved therewith, not specifically
shown or described herein, can be selected from such systems,
algorithms, components and elements known in the art. Given the
system as described according to the invention in the following
materials, software not specifically shown, suggested or described
herein that is useful for implementation of the invention is
conventional and within the ordinary skill in such arts.
[0031] Still further, as used herein, a computer program for
performing the method of the present invention can be stored in a
computer readable storage medium, which can include, for example;
magnetic storage media such as a magnetic disk (such as a hard
drive or a floppy disk) or magnetic tape; optical storage media
such as an optical disc, optical tape, or machine readable bar
code; solid state electronic storage devices such as random access
memory (RAM), or read only memory (ROM); or any other physical
device or medium employed to store a computer program having
instructions for controlling one or more computers to practice the
method according to the present invention.
[0032] Because digital cameras employing imaging devices and
related circuitry for signal capture and processing, and display
are well known, the present description will be directed in
particular to elements forming part of, or cooperating more
directly with, the method and apparatus in accordance with the
present invention. Elements not specifically shown or described
herein are selected from those known in the art. Certain aspects of
the embodiments to be described are provided in software. Given the
system as shown and described according to the invention in the
following materials, software not specifically shown, described or
suggested herein that is useful for implementation of the invention
is conventional and within the ordinary skill in such arts.
[0033] The disclosure is inclusive of combinations of the
embodiments described herein. References to "a particular
embodiment" and the like refer to features that are present in at
least one embodiment of the invention. Separate references to "an
embodiment" or "particular embodiments" or the like do not
necessarily refer to the same embodiment or embodiments; however,
such embodiments are not mutually exclusive, unless so indicated or
as are readily apparent to one of skill in the art. The use of
singular or plural in referring to the "method" or "methods" and
the like is not limiting. It should be noted that, unless otherwise
explicitly noted or required by context, the word "or" is used in
this disclosure in a non-exclusive sense.
[0034] The following description of a digital camera will be
familiar to one skilled in the art. It will be obvious that there
are many variations of this embodiment that are possible and are
selected to reduce the cost, add features or improve the
performance of the camera.
[0035] FIG. 1 depicts a block diagram of a digital photography
system, including a digital camera 10. Preferably, the digital
camera 10 is a portable battery operated device, small enough to be
easily handheld by a user when capturing and reviewing images. The
digital camera 10 produces digital images that are stored as
digital image files using image memory 30. The phrase "digital
image" or "digital image file", as used herein, refers to any
digital image file, such as a digital still image or a digital
video file.
[0036] In some embodiments, the digital camera 10 captures both
motion video images and still images. The digital camera 10 can
also include other functions, including, but not limited to, the
functions of a digital music player (e.g. an MP3 player), a mobile
telephone, a GPS receiver, or a programmable digital assistant
(PDA).
[0037] The digital camera 10 includes a lens 4 having an adjustable
aperture and adjustable shutter 6. In a preferred embodiment, the
lens 4 is a zoom lens and is controlled by zoom and focus motor
drives 8. The lens 4 focuses light from a scene (not shown) onto an
image sensor 14, for example, a single-chip color CCD or CMOS image
sensor. The lens 4 is one type optical system for forming an image
of the scene on the image sensor 14. In other embodiments, the
optical system may use a fixed focal length lens with either
variable or fixed focus.
[0038] The output of the image sensor 14 is converted to digital
form by Analog Signal Processor (ASP) and Analog-to-Digital (A/D)
converter 16, and temporarily stored in buffer memory 18. The image
data stored in buffer memory 18 is subsequently manipulated by a
processor 20, using embedded software programs (e.g. firmware)
stored in firmware memory 28. In some embodiments, the software
program is permanently stored in firmware memory 28 using a read
only memory (ROM). In other embodiments, the firmware memory 28 can
be modified by using, for example, Flash EPROM memory. In such
embodiments, an external device can update the software programs
stored in firmware memory 28 using the wired interface 38 or the
wireless modem 50. In such embodiments, the firmware memory 28 can
also be used to store image sensor calibration data, user setting
selections and other data which must be preserved when the camera
is turned off. In some embodiments, the processor 20 includes a
program memory (not shown), and the software programs stored in the
firmware memory 28 are copied into the program memory before being
executed by the processor 20.
[0039] It will be understood that the functions of processor 20 can
be provided using a single programmable processor or by using
multiple programmable processors, including one or more digital
signal processor (DSP) devices. Alternatively, the processor 20 can
be provided by custom circuitry (e.g., by one or more custom
integrated circuits (ICs) designed specifically for use in digital
cameras), or by a combination of programmable processor(s) and
custom circuits. It will be understood that connectors between the
processor 20 from some or all of the various components shown in
FIG. 1 can be made using a common data bus. For example, in some
embodiments the connection between the processor 20, the buffer
memory 18, the image memory 30, and the firmware memory 28 can be
made using a common data bus.
[0040] The processed images are then stored using the image memory
30. It is understood that the image memory 30 can be any form of
memory known to those skilled in the art including, but not limited
to, a removable Flash memory card, internal Flash memory chips,
magnetic memory, or optical memory. In some embodiments, the image
memory 30 can include both internal Flash memory chips and a
standard interface to a removable Flash memory card, such as a
Secure Digital (SD) card. Alternatively, a different memory card
format can be used, such as a micro SD card, Compact Flash (CF)
card, MultiMedia Card (MMC), xD card or Memory Stick.
[0041] The image sensor 14 is controlled by a timing generator 12,
which produces various clocking signals to select rows and pixels
and synchronizes the operation of the ASP and AID converter 16. The
image sensor 14 can have, for example, 12.4 megapixels
(4088.times.3040 pixels) in order to provide a still image file of
approximately 4000.times.3000 pixels. To provide a color image, the
image sensor is generally overlaid with a color filter array, which
provides an image sensor having an array of pixels that include
different colored pixels. The different color pixels can be
arranged in many different patterns. As one example, the different
color pixels can be arranged using the well-known Bayer color
filter array, as described in commonly assigned U.S. Pat. No.
3,971,065, "Color imaging array" to Bayer, the disclosure of which
is incorporated herein by reference. As a second example, the
different color pixels can be arranged as described in commonly
assigned US patent application number U.S. Patent Application
Publication 2007/0024931, filed on Jul. 28, 2007 and titled "Image
sensor with improved light sensitivity" to Compton and Hamilton,
the disclosure of which is incorporated herein by reference. These
examples are not limiting, and many other color patterns may be
used.
[0042] It will be understood that the image sensor 14, timing
generator 12, and ASP and A/D converter 16 can be separately
fabricated integrated circuits, or they can be fabricated as a
single integrated circuit as is commonly done with CMOS image
sensors. In some embodiments, this single integrated circuit can
perform some of the other functions shown in FIG. 1, including some
of the functions provided by processor 20.
[0043] The image sensor 14 is effective when actuated in a first
mode by timing generator 12 for providing a motion sequence of
lower resolution sensor image data, which is used when capturing
video images and also when previewing a still image to be captured,
in order to compose the image. This preview mode sensor image data
can be provided as HD resolution image data, for example, with
1280.times.720 pixels, or as VGA resolution image data, for
example, with 640.times.480 pixels, or using other resolutions
which have significantly fewer columns and rows of data, compared
to the resolution of the image sensor.
[0044] The preview mode sensor image data can be provided by
combining values of adjacent pixels having the same color, or by
eliminating some of the pixels values, or by combining some color
pixels values while eliminating other color pixel values. The
preview mode image data can be processed as described in commonly
assigned U.S. Pat. No. 6,292,218 to Parulski, et al., entitled
"Electronic camera for initiating capture of still images while
previewing motion images," which is incorporated herein by
reference.
[0045] The image sensor 14 is also effective when actuated in a
second mode by timing generator 12 for providing high resolution
still image data. This final mode sensor image data is provided as
high resolution output image data, which for scenes having a high
illumination level includes all of the pixels of the image sensor,
and can be, for example, a 12 megapixel final image data having
4000.times.3000 pixels. At lower illumination levels, the final
sensor image data can be provided by "binning" some number of
like-colored pixels on the image sensor, in order to increase the
signal level and thus the "ISO speed" of the sensor.
[0046] The zoom and focus motor drivers 8 are controlled by control
signals supplied by the processor 20, to provide the appropriate
focal length setting and to focus the scene onto the image sensor
14. The exposure level of the image sensor 14 is controlled by
controlling the f/number and exposure time of the adjustable
aperture and adjustable shutter 6, the exposure period of the image
sensor 14 via the timing generator 12, and the gain (i.e., ISO
speed) setting of the ASP and A/D converter 16. The processor 20
also controls a flash 2 which can illuminate the scene.
[0047] The lens 4 of the digital camera 10 can be focused in the
first mode by using "through-the-lens" autofocus, as described in
commonly-assigned U.S. Pat. No. 5,668,597, entitled "Electronic
Camera with Rapid Automatic Focus of an Image upon a Progressive
Scan Image Sensor" to Parulski et al., which is incorporated herein
by reference. This is accomplished by using the zoom and focus
motor drivers 8 to adjust the focus position of the lens 4 to a
number of positions ranging between a near focus position to an
infinity focus position, while the digital processor 20 determines
the closest focus position which provides a peak sharpness value
for a central portion of the image captured by the image sensor 14.
The focus distance which corresponds to the closest focus position
can then be utilized for several purposes, such as automatically
setting an appropriate scene mode, and can be stored as metadata in
the image file, along with other lens and camera settings.
[0048] An optional auxiliary sensor 42 can be used to sense
information about the scene or the viewing environment. For
example, the auxiliary sensor 42 can be a light sensor for
measuring an illumination level of the scene in order to set the
proper exposure level. Alternatively, the auxiliary sensor 42 can
be an environmental sensor used to characterize the viewing
environment in which images are being viewed on an image display
32. Those skilled in the art will recognize that many other types
of auxiliary sensors 42 can also be used.
[0049] The processor 20 produces menus and low resolution color
images that are temporarily stored in display memory 36 and are
displayed on the image display 32. The image display 32 is
typically an active matrix color liquid crystal display (LCD),
although other types of displays, such as organic light emitting
diode (OLED) displays, can be used. A video interface 44 provides a
video output signal from the digital camera 10 to a video display
46, such as a flat panel HDTV display. In preview mode, or video
mode, the digital image data from buffer memory 18 is manipulated
by processor 20 to form a series of motion preview images that are
displayed, typically as color images, on the image display 32. In
review mode, the images displayed on the image display 32 are
produced using the image data from the digital image files stored
in image memory 30.
[0050] The graphical user interface displayed on the color LCD
image display 32 is controlled in response to user input provided
by user controls 34. The user controls 34 are used to select
various camera modes, such as video capture mode, still capture
mode, and review mode, and to initiate capture of still images and
recording of motion images. In some embodiments, the first mode
described above (i.e. still preview mode) is initiated when the
user partially depresses a shutter button (e.g., image capture
button 240 shown in FIG. 4), which is one of the user controls 34,
and the second mode (i.e., still image capture mode) is initiated
when the user fully depresses the shutter button. The user controls
34 are also used to turn on the camera, control the lens 4, and
initiate the picture taking process. User controls 34 typically
include some combination of buttons, rocker switches, joysticks, or
rotary dials. In some embodiments, some of the user controls 34 are
provided by using a touch screen overlay on the image display 32.
In other embodiments, additional status displays or images displays
can be used.
[0051] The camera modes that can be selected using the user
controls 34 include a "self portrait" mode, which will be described
later with respect to FIG. 4, and a "timer" mode. When the "timer"
mode is selected, a short delay (e.g., 10 seconds) occurs after the
user fully presses the shutter button, before the processor 20
initiates the capture of a still image.
[0052] One or more signal lights 25 on the digital camera 10 can be
used to provide visual feedback to the user when a self-portrait is
being captured, as will be described later with respect to FIG.
4.
[0053] An audio codec 22 connected to the processor 20 receives an
audio signal from a microphone 24 and provides an audio signal to a
speaker 26. These components can be to record and playback an audio
track, along with a video sequence or still image. If the digital
camera 10 is a multi-function device such as a combination camera
and mobile phone, the microphone 24 and the speaker 26 can be used
for telephone conversation.
[0054] In some embodiments, the speaker 26 can be used as part of
the user interface, for example to provide various audible signals
which indicate that a user control has been depressed, or that a
particular mode has been selected, or to provide feedback to the
user when a self-portrait is being captured. In some embodiments,
the microphone 24, the audio codec 22, and the processor 20 can be
used to provide voice recognition, so that the user can provide a
user input to the processor 20 by using voice commands, rather than
user controls 34. The speaker 26 can also be used to inform the
user of an incoming phone call. This can be done using a standard
ring tone stored in firmware memory 28, or by using a custom
ring-tone downloaded from a wireless network 58 and stored in the
image memory 30. In addition, a vibration device (not shown) can be
used to provide a silent (e.g., non audible) notification of an
incoming phone call.
[0055] The processor 20 also provides additional processing of the
image data from the image sensor 14, in order to produce rendered
sRGB image data which is compressed and stored within a "finished"
image file, such as a well-known Exif-JPEG image file, in the image
memory 30.
[0056] The digital camera 10 can be connected via the wired
interface 38 to an interface/recharger 48, which is connected to a
computer 40, which can be a desktop computer or portable computer
located in a home or office. The wired interface 38 can conform to,
for example, the well-known USB 2.0 interface specification. The
interface/recharger 48 can provide power via the wired interface 38
to a set of rechargeable batteries (not shown) in the digital
camera 10.
[0057] The digital camera 10 can include a wireless modem 50, which
interfaces over a radio frequency band 52 with the wireless network
58. The wireless modem 50 can use various wireless interface
protocols, such as the well-known Bluetooth wireless interface or
the well-known 802.11 wireless interface. The computer 40 can
upload images via the Internet 70 to a photo service provider 72,
such as the Kodak Easy Share Gallery. Other devices (not shown) can
access the images stored by the photo service provider 72.
[0058] In alternative embodiments, the wireless modem 50
communicates over a radio frequency (e.g. wireless) link with a
mobile phone network (not shown), such as a 3GSM network, which
connects with the Internet 70 in order to upload digital image
files from the digital camera 10. These digital image files can be
provided to the computer 40 or the photo service provider 72.
[0059] FIG. 2 is a flow diagram depicting image processing
operations that can be performed by the processor 20 in the digital
camera 10 (FIG. 1) in order to process color sensor data 100 from
the image sensor 14 output by the ASP and A/D converter 16. In some
embodiments, the processing parameters used by the processor 20 to
manipulate the color sensor data 100 for a particular digital image
are determined by various user settings 175, which can be selected
via the user controls 34 in response to menus displayed on the
image display 32.
[0060] The color sensor data 100 which has been digitally converted
by the ASP and A/D converter 16 is manipulated by a sensor noise
reduction step 105 in order to reduce noise from the image sensor
14. In some embodiments, this processing can be performed using the
methods described in commonly-assigned U.S. Pat. No. 6,934,056 to
Gindele et al., entitled "Noise cleaning and interpolating sparsely
populated color digital image using a variable noise cleaning
kernel," the disclosure of which is herein incorporated by
reference. The level of noise reduction can be adjusted in response
to an ISO setting 110, so that more filtering is performed at
higher ISO exposure index setting.
[0061] The color image data is then manipulated by a demosaicing
step 115, in order to provide red, green and blue (RGB) image data
values at each pixel location. Algorithms for performing the
demosaicing step 115 are commonly known as color filter array (CFA)
interpolation algorithms or "deBayering" algorithms. In one
embodiment of the present invention, the demosaicing step 115 can
use the luminance CFA interpolation method described in
commonly-assigned U.S. Pat. No. 5,652,621, entitled "Adaptive color
plane interpolation in single sensor color electronic camera," to
Adams et al., the disclosure of which is incorporated herein by
reference. The demosaicing step 115 can also use the chrominance
CFA interpolation method described in commonly-assigned U.S. Pat.
No. 4,642,678, entitled "Signal processing method and apparatus for
producing interpolated chrominance values in a sampled color image
signal", to Cok, the disclosure of which is herein incorporated by
reference.
[0062] In some embodiments, the user can select between different
pixel resolution modes, so that the digital camera can produce a
smaller size image. Multiple pixel resolutions can be provided as
described in commonly-assigned U.S. Pat. No. 5,493,335, entitled
"Single sensor color camera with user selectable image record
size," to Parulski et al., the disclosure of which is herein
incorporated by reference. In some embodiments, a resolution mode
setting 120 can be selected by the user to be full size (e.g.
3,000.times.2,000 pixels), medium size (e.g. 1,500.times.1000
pixels) or small size (750.times.500 pixels).
[0063] The color image data is color corrected in color correction
step 125. In some embodiments, the color correction is provided
using a 3.times.3 linear space color correction matrix, as
described in commonly-assigned U.S. Pat. No. 5,189,511, entitled
"Method and apparatus for improving the color rendition of hardcopy
images from electronic cameras" to Parulski, et al., the disclosure
of which is incorporated herein by reference. In some embodiments,
different user-selectable color modes can be provided by storing
different color matrix coefficients in firmware memory 28 of the
digital camera 10. For example, four different color modes can be
provided, so that the color mode setting 130 is used to select one
of the following color correction matrices:
Setting 1 (normal color reproduction)
[ R out G out B out ] = [ 1.50 - 0.30 - 0.20 - 0.40 1.80 - 0.40 -
0.20 - 0.20 1.40 ] [ R in G in B in ] ( 1 ) ##EQU00001##
Setting 2 (saturated color reproduction)
[ R out G out B out ] = [ 2.00 - 0.60 - 0.40 - 0.80 2.60 - 0.80 -
0.40 - 0.40 1.80 ] [ R in G in B in ] ( 2 ) ##EQU00002##
Setting 3 (de-saturated color reproduction)
[ R out G out B out ] = [ 1.25 - 0.15 - 0.10 - 0.20 1.40 - 0.20 -
0.10 - 0.10 1.20 ] [ R in G in B in ] ( 3 ) ##EQU00003##
Setting 4 (monochrome)
[ R out G out B out ] = [ 0.30 0.60 0.10 0.30 0.60 0.10 0.30 0.60
0.10 ] [ R in G in B in ] ( 4 ) ##EQU00004##
[0064] In other embodiments, a three-dimensional lookup table can
be used to perform the color correction step 125.
[0065] The color image data is also manipulated by a tone scale
correction step 135. In some embodiments, the tone scale correction
step 135 can be performed using a one-dimensional look-up table as
described in U.S. Pat. No. 5,189,511, cited earlier. In some
embodiments, a plurality of tone scale correction look-up tables is
stored in the firmware memory 28 in the digital camera 10. These
can include look-up tables which provide a "normal" tone scale
correction curve, a "high contrast" tone scale correction curve,
and a "low contrast" tone scale correction curve. A user selected
contrast setting 140 is used by the processor 20 to determine which
of the tone scale correction look-up tables to use when performing
the tone scale correction step 135.
[0066] The color image data is also manipulated by a face
detection/recognition step 185. In some embodiments, face detection
can be provided using the methods described in commonly-assigned
U.S. Pat. No. 7,583,294, entitled "Face detecting camera and
method" to Ray, et al, the disclosure of which is incorporated
herein by reference. This patent teaches a method for determining
the presence of a face from image data that utilizes a first
algorithm to prescreen the image data, by determining a plurality
of face candidates utilizing a pattern matching technique that
identifies image windows likely to contain faces based on color and
shape information, and a second algorithm that processes the face
candidates determined by the first algorithm, and uses a posterior
probability function classifier to determine the presence of the
face. The output of the face detection/recognition step 185 can
include metadata that identifies the location of any faces that are
detected.
[0067] In some embodiments, the face detection/recognition step 185
can recognize specific faces in images, as described in
commonly-assigned U.S. Pat. No. 7,660,445 to Ray, entitled "Method
for selecting an emphasis image from an image collection based upon
content recognition," the disclosure of which is incorporated
herein by reference. For example, the face recognition step 175
could be used to recognize the face of the user of the digital
camera 10. The output of step 175 can include metadata that
identifies the names or other identifiers for specific faces that
are detected.
[0068] The color image data is also manipulated by an image
sharpening step 145. In some embodiments, this can be provided
using the methods described in commonly-assigned U.S. Pat. No.
6,192,162 entitled "Edge enhancing colored digital images" to
Hamilton, et al., the disclosure of which is incorporated herein by
reference. In some embodiments, the user can select between various
sharpening settings, including a "normal sharpness" setting, a
"high sharpness" setting, and a "low sharpness" setting. In this
example, the processor 20 uses one of three different edge boost
multiplier values, for example 2.0 for "high sharpness", 1.0 for
"normal sharpness", and 0.5 for "low sharpness" levels, responsive
to a sharpening setting 150 selected by the user of the digital
camera 10.
[0069] The color image data is also manipulated by an image
compression step 155. In some embodiments, the image compression
step 155 can be provided using the methods described in
commonly-assigned U.S. Pat. No. 4,774,574, entitled "Adaptive block
transform image coding method and apparatus" to Daly et al., the
disclosure of which is incorporated herein by reference. In some
embodiments, the user can select between various compression
settings. This can be implemented by storing a plurality of
quantization tables, for example, three different tables, in the
firmware memory 28 of the digital camera 10. These tables provide
different quality levels and average file sizes for the compressed
digital image file 180 to be stored in the image memory 30 of the
digital camera 10. A user selected compression mode setting 160 is
used by the processor 20 to select the particular quantization
table to be used for the image compression step 155 for a
particular image.
[0070] The compressed color image data is stored in a digital image
file 180 using a file formatting step 165. The image file can
include various metadata 170. Metadata 170 is any type of
information that relates to the digital image, such as the model of
the camera that captured the image, the size of the image, the date
and time the image was captured, and various camera settings, such
as the lens focal length, the exposure time and f-number of the
lens, and whether or not the camera flash fired. In a preferred
embodiment, all of this metadata 170 is stored using standardized
tags within the well-known Exif-JPEG still image file format.
[0071] The present invention will now be described with reference
to FIG. 3. One common usage for a digital camera 10 is for a
photographer 210 to capture a self-portrait image that includes the
photographer 210 by holding the digital camera 10 at arms length,
pointing it back toward himself. The self-portrait image may
contain only one person (i.e., the photographer 210). Alternately,
the self-portrait image may optionally contain one or more
additional persons 220.
[0072] According to the present invention, while the photographer
210 is adjusting the composition of the photograph, an image sensor
14 (FIG. 1) in the digital camera 10 is sensing the scene being
imaged onto the image sensor by the lens 4 of the digital camera
10. A processor within the digital camera processes the output of
the image sensor and performs a face detection operation to detect
the presence of one or more faces in a field of view of the digital
camera 10. When the processor detects the presence of at least one
face in the field of view, feedback is provided to the photographer
210. The photographer 210 can then initiate capturing a digital
image using a user control 34 provided for the digital camera
10.
[0073] FIG. 4 is a diagram showing additional details of a digital
camera 10 incorporating the present invention. An lens 4 is
provided to image a scene onto the digital sensor (not shown). The
photographer 210 uses one of the user controls 34 (FIG. 1), such as
image capture button 240, to initiate capture of a digital image.
Various feedback mechanisms can be used to provide either visual or
audio feedback to the photographer. For example, visual feedback
can be provided using one or more signal lights 25 and audio
feedback can be provided using speaker 26. The digital camera 10
can also provide feedback using any other feature known to one
skilled in the art such as by emitting a light from flash 2, by
displaying text messages or icons on a status display (not shown)
on the front of the digital camera 10, or by causing tactile
vibrations of some portion of the digital camera 10 using a
vibratory element (not shown). The vibratory element has the
advantage of reducing cost in cell phones or other devices that
already have such elements for other purposes. The vibration ceases
when the image is captured in order to avoid introducing motion
blur in the captured image.
[0074] Optionally, other forms of user controls besides image
capture button 240 can be provided to initiate capturing an image.
For example, a remote control, or a voice activation mechanism
using microphone 24 can all be used to initiate an image capture
event. Alternatively, an existing button (not shown) which is not
image capture button 240 can be repurposed to act as the "shutter
button" when camera 200 is in self-portrait mode, or a secondary
image capture button (not shown) can be included on the digital
camera 10 and used in self-portrait mode, in order to provide a
user control which can be more easily activated by the photographer
210 when the digital camera 10 is held as shown in FIG. 3. In some
embodiments, a time delay is provided between when the user
initiates the image capture event and when the digital image is
captured, in order to reduce camera vibrations or allow the
photographer time to pose.
[0075] A flowchart showing steps for providing visual or audio
feedback to the photographer according to the present invention is
shown in FIG. 5. A capture preview image step 300 is used to
capture a preview image 302 of a scene within the field of view of
the lens 4 (FIG. 1 and FIG. 4) using the image sensor 14 (FIG. 1)
while the digital camera 10 is operating in the first capture mode
described earlier in reference to FIG. 1. The processor 20 is used
to process the preview images 302 using a face determination step
305. In a preferred embodiment, the face determination step 305
determines whether the face of the photographer 210 is included in
the field of view of the lens 4, by determining the number and
location of any faces in the field of view. In some embodiments,
this can be done by detecting whether or not at least one face of
suitable size is included in the preview image 302, using face
detection methods such as those described earlier with reference to
the face detection/recognition step 185 of FIG. 2. In other
embodiments, this can be done by further determining whether or not
a detected face is the face of the photographer 210, using face
recognition methods such as those described earlier in reference to
the face detection/recognition step 185 of FIG. 2. The face
determination step 305 can further determine whether there are
multiple faces of a suitable size within the field of view of the
lens 4, and whether the detected faces are positioned such that no
significant portion of the face (e.g. the top portion of the head
of additional person 220) is located outside of the field of view
of the lens 4.
[0076] A determine feedback step 310 is used to determine
appropriate user feedback 315 responsive to whether one or more
faces were detected by the face determination step 305. Optionally,
the user feedback 315 provided by the determine feedback step 310
may further be responsive to a camera mode 320 or a face distance
325. The camera mode 320 can be selected by the photographer using
user controls 34 as described earlier in reference to FIG. 1. The
face distance 325 can be the lens focus distance, provided using
the through-the-lens autofocus method discussed earlier in
reference to FIG. 1. There are many other auto focus mechanisms
that are well-known to those skilled in the art, such as
correlation autofocus methods, that can be used instead of
through-the-lens autofocus, in accordance with the present
invention. Alternately, the face distance 325 can be estimated from
the size of the detected faces or the eye spacing relative to the
overall size of the image frame together with the focal length of
the lens 4.
[0077] FIG. 6 is a flow-chart showing additional details for the
determine feedback step 310 according to one embodiment of the
present invention. The face determination step 305 provides an
indication of whether at least one face is present in the field of
view of the digital camera. A face present test 400 evaluates the
output of the face detection step 305. If no faces are present, no
user feedback 315 is provided to the user. In an alternate
embodiment, negative user feedback is provided to the user rather
than providing no user feedback.
[0078] If the face present test 400 determines that at least one
face is present, a self-portrait mode test 405 is used to determine
whether the digital camera is in a camera mode 320 where user
feedback 315 regarding the presence of faces in the digital image
is desired. If the camera mode 320 is not a self-portrait mode, no
user feedback 415 is provided. In one embodiment of the present
invention, user feedback is only provided when the camera mode 320
is set to a special self-portrait camera mode as described earlier
with reference to FIG. 1. In some embodiments no self portrait mode
test 405 is used and user feedback 315 is provided independent of
the camera mode 320.
[0079] A within distance range test 410 determines whether the face
distance 325 is within a specified face distance range. There is a
finite range of face distances at which a user can hold a camera at
arm's length. For the purpose of example, we will assume that
distance is less than one meter. When the camera detects that the
face distance is one meter or less, an assumption can be made that
the user is holding the camera at arm's length. This assumption
will be erroneous for the case where the digital camera is being
used for macro photography. For digital cameras that support a
macro photography mode, the specified face distance range can also
include a minimum face distance such as 0.3 meters. If the face
distance 325 is within the specified face distance range, no user
feedback 415 is provided to the user. Otherwise, positive user
feedback 420 is provided indicating that there is at least one face
in the field of view of the digital camera.
[0080] In an alternate embodiment of the present invention, when
the face distance 325 is detected to be within the specified face
distance range, the camera mode 320 for the digital camera
automatically switches to a self-portrait mode. This alleviates the
need for the user to explicitly select a self-portrait mode with
the user interface. In one variation, the user can use the user
interface to indicate whether the self portrait mode should be
manually or automatically selected.
[0081] The determine feedback step 310 can also incorporate other
tests in accordance with the present invention. For example, a test
can be added which compares a size of the detected face relative to
the field of view for the camera to a specified size range that
would be expected for self-portraits captured by the photographer
holding the camera at arm's length. This test can be helpful to
make sure that the digital camera is pointing at the photographer
rather than someone in the background. In addition, different types
of feedback can be provided based on whether a portion of a
detected face is located outside of the field of view of the lens 4
and will be cropped when the image is captured by the digital
camera 10. The feedback can be used to help guide the photographer
210 to adjust the position of the digital camera 10 in order to
reduce or eliminate this cropping, by ensuring that the user is
positioned within a "preferred face zone". For example, audio
suggestions can be provided to "tilt camera up" or "tilt camera
left." These suggestions can also be provided by providing blinking
lights or by using text or icons on a status or image display (not
shown) on the front of the digital camera 10, as will be described
later.
[0082] There may be various camera settings appropriate for use in
the self-portrait camera mode. For example, there may be a smallest
practical aperture to provide a large depth of field since often,
the user will use the self-portrait camera mode to capture an image
of himself against a background as a record of his presence in a
particular place. The small aperture and associated longer capture
time may also be appropriate since in most cases, both the subject
and the background will be stationary. However, the use of long
exposures must be balanced versus the ability of the user to hold
the camera steady. If the camera is equipped with accelerometers or
some other ability to sense motion, such as motion analysis of
pre-capture video, the time of capture can be automatically
adjusted to occur when the camera is determined to be motionless or
close to motionless. Additionally, if the camera is so equipped,
the flash illumination can be controlled such that the light on the
user's face is not unbalanced with that from the remainder of the
scene.
[0083] Another camera setting for the self-portrait camera mode is
the use of the wide angle setting when the digital camera 10 has a
lens 4, which is a zoom lens rather than a fixed focal length lens.
Typically, the user desires a self-portrait with the particular
aspects of the location. The user's face should be recognizable,
but not dominating the field of capture. In the self-portrait
camera mode, the camera should generally be at the lowest
magnification setting to maximize the field of view.
[0084] The user feedback 315 can be provided in many different ways
in accordance with the present invention using audio or visual
cues. When the digital camera is used in a video capture mode, it
will generally be preferable to use a visual means of indication so
that audible indications are not recorded. For example, a signal
light 25, such as a light-emitting diode (LED), provided on the
front of the camera can light up, or can be caused to blink, to
show that the a face has been detected within the image at an
appropriate face distance range while the camera is operating in
the self-portrait camera mode.
[0085] In an alternate embodiment, the flash 2 can be pulsed to
provide the visual feedback. This has the advantage of reducing
cost by eliminating the need for an additional signal light 25.
Many other visual signal means can also be used in accordance with
the present invention. For example, a small image display could be
used to show a low-resolution version of the captured image,
however this approach will generally not be desirable because of
the added cost that is associated with adding an image display to
the digital camera.
[0086] The visual means of indication can also be used to provide
additional information besides simply indicating that a face has
been detected within the image. For example, a blink rate for the
signal light 25 can be adjusted to provide an indication of the
face location within the image. When the face or faces are detected
within a preferred face zone in the image, the signal light 25 can
be caused to blink more rapidly than when a face is detected at an
edge of the image. This can enable the user to make sure that the
field of view for the camera is optimally oriented.
[0087] The preferred face zone can be defined according to various
composition rules. For example, if only one face is detected in the
field of view, it will generally be desirable to position the face
slightly off-center in the field of view according to the
well-known "rule of thirds." This is desirable because it allows
the background to be adequately represented in the captured image.
This is illustrated in FIG. 7. In this example, two preferred face
zones 460 are defined within the digital image 430 which correspond
to aesthetically pleasing face locations. When a face 440 is
detected within one of the preferred face zones 460, it can be
concluded that the photographer 450 is properly positioned relative
to a background 470 according to the defined composition rules,
thus providing an unobscured view of the background 470. Different
photographers may have different preferences for composition rules.
For example, one photographer may prefer images captured using the
rule of thirds, while another may prefer images captured with the
face centered in the image. In one embodiment, a user interface can
be provided to allow the photographer to select preferred
composition rules.
[0088] It can also be desirable to use different composition rules
depending on the number of faces that are detected within the
image. For example, it may be desirable to use the rule of thirds
when the photographer is the only person in the image. However, if
two or more faces are detected in the image, it may be preferable
to center the faces within the field of view. To incorporate this
factor, the determine feedback step 310 (FIG. 5) can select
different composition rules depending on the number of faces
detected by the face detection step 305 (FIG. 5).
[0089] Other means besides changing the blink rate for the signal
light 25 can be used to provide additional information. For
example, a blink duty cycle, a signal light color, a signal light
intensity or combinations thereof can also be used. Other
embodiments would involve using multiple signal lights. For
example, one light can be lit when a face is detected within the
digital image 430, and a second light can be lit when the face is
within a preferred face zone 460.
[0090] The user feedback 315 can also be used to provide an
indication of what the photographer must do to improve the
composition. For example, three signal lights can be provided in a
row as shown in FIG. 8: a left signal light 500, a center signal
light 510 and a right signal light 520. When a face is detected
within a preferred face zone 460 (FIG. 7), the center signal light
510 can be lit. But when a face is detected outside of the
preferred face zone 460, the other signal lights can provide an
indication of what direction the user should move the camera to
correct the composition. If the photographer needs to reorient the
camera to the left, the left signal light 500 can be lit, and if
the photographer needs to reorient the camera to the right, the
right signal light 520 can be lit. In another embodiment the left
signal light 500 and the right signal light 520 can have an arrow
shape pointing in the direction that the photographer needs to
reorient the camera. Similar means could be provided to given the
photographer an indication of whether the camera needs to be
reoriented vertically.
[0091] The user feedback 315 can also be used to provide an
indication of the number of detected faces within the field of view
of the camera. This can be useful for the photographer to verify
that the camera is oriented properly for group photographs. For
example, if the photographer 210 is attempting to capture a photo
with additional person 220 as was shown in FIG. 3, it would be
useful to verify that both of the faces fall within the field of
view of the camera. In one embodiment, a multiple signal light
configuration like that shown in FIG. 8 can be used to provide the
indication of the number of detected faces. If one face is
detected, a single signal light can be lit. Similarly, if two faces
are detected, two signal lights can be lit, and if three or more
faces are detected, all three signal lights can be lit. In an
alternate embodiment, a small alphanumeric status display can be
provided and a number can be displayed showing the number of
detected faces.
[0092] Various forms of audio user feedback mechanisms can also be
user in accordance with the present invention. For example, audio
feedback can be provided by using the speaker to provide verbal
commands to the user by using voice synthesis or by playing
pre-recorded voice commands. Alternately, non-verbal audio signals
can be provided such as playing various tones or sounds responsive
to detecting one or more faces in the digital image.
[0093] As with the visual feedback mechanisms described above, the
audio feedback mechanisms can also be used to provide additional
information beyond whether or not a face has been detected. For
example, the speech content of verbal audio signals can be used to
provide verbal instructions to the user. For example, verbal
instructions can tell the user which direction the camera should be
reoriented in order to move the detected faces to positions
consistent with defined composition rules. Similarly, the verbal
instructions could indicate the number of faces that are detected
within the field of view.
[0094] When non-verbal audio signals are used, additional
information can be communicated by adjusting attributes such as the
frequency, volume or duty cycle of the audio signals. For example,
while the photographer is orienting the digital camera, the volume
of an audio feedback may be raised as the user approaches the
preferred composition and stay at a particular high volume until
the pointing has changed such that the user is leaving the
preferred composition. Alternatively, similar feedback may be
provided by means of rising and falling pitch, or by a frequency or
duration of a single tone. Similarly, the patterns of the audio
signals can be used to provide an indication of the number of faces
that have been detected. For example, if two faces are detected, a
characteristic repetitive feedback pattern can be provided such as
two blinks or beeps followed by a pause. Additional faces can
provide different indication patterns.
[0095] Alternately, different audio signals can be used to indicate
different conditions, similar to the way cell phones can use
different ring tones to indicate different communication events. In
some embodiments, a user interface can be provided to enable the
photographer to select preferred audio signals that are used to
indicate different conditions.
[0096] In many cases, components that already exist on most digital
cameras can be used to provide the user feedback without the need
to add any additional components. For example, the digital camera
10 may already incorporate a speaker 26 for providing audible
indicators for other reasons, such as for playing back sounds
recorded by the digital camera 10 during video mode, or for
indicating that image capture has taken place or for indicating
error conditions. Therefore, audio feedback can be provided using
the existing speaker without requiring any additional component
costs. Similarly, many digital cameras also incorporate
pre-existing components that can be used to provide visual
indicators. For example, an LED signal light is commonly provided
to indicate battery charging. In this case, it would be necessary
to position the visual indicator such that it is visible from the
front of the camera.
[0097] In some embodiments, the user controls 34 can be used to
enable the photographer to select a preferred form of user
feedback. For example, menu options can be provided in a user
interface that allows the photographer to select between providing
visual feedback using signal lights, audio feedback using verbal
commands, or audio feedback using non-verbal signals or tactile
feedback.
[0098] For cases when multiple photographers may use a particular
digital camera, each photographer may have different preferred
forms of user feedback. In this case, the digital camera may be
configured to allow multiple sets of preference settings. In one
embodiment of the present invention, the face determination step
305 can also be trained to provide an indication of the identity of
the detected faces in addition to the number and location of the
identified faces, as was described earlier in reference to FIG. 5.
In this case, the identity of the photographer can be inferred from
the identified face and the appropriate set of preference settings
can be automatically selected.
[0099] The self-portrait mode can differ from conventional
portraiture modes in that there are generally dual subjects of
importance. For portraiture, the subject is the face and upper body
of a person. The background is generally of secondary importance.
In the self-portrait mode, both the face of the subject and the
background are generally important, and an adequate representation
of both should be obtained to attain the desired record of user
presence at a location. In one embodiment, when a single face is
detected in the center of the frame, the digital camera can be
automatically changed to a conventional portraiture mode and an
indication of this can be provided to the user by any appropriate
user feedback mechanism.
[0100] In one embodiment, selection of the self-portrait mode may
provide an image capture process where image capture occurs only
after specific criteria are met. For example, the user may manually
select the self-portrait mode using user controls 34 on the back of
the digital camera 10 with the lens 4 pointed away from the
photographer 210. Once the self-portrait mode has been entered, the
digital camera 10 captures preview images 302 and processes these
preview images 302 until a set of criteria are satisfied. In
addition to the criteria described with reference to FIG. 6, other
criteria that could be evaluated would include waiting until all
eyes are open, all faces are smiling and camera motion is
minimized. The camera can use the aforementioned indicators to
alert the photographer 210 that the criteria have been met so that
image capture can be manually initiated by the photographer 210.
Alternatively, the digital camera 10 can be configured so that
image capture is automatically initiated when all of the criteria
have been met. An advantage of providing such an automatic capture
mode is that the photographer 210 need not press the image capture
button 240, which can be awkward, and may impart undesirable motion
to the digital camera 10 during capture.
[0101] In an alternate embodiment, the portion of the image that is
not the face or body of the photographer can be analyzed to provide
additional guidance to the photographer as to how the composition
of the photograph should be adjusted. For example, even if the face
is located within a preferred face zone 460 (FIG. 7), the digital
camera may be pointing such that the background is the sky rather
than the background of interest. In this case, if the background
were determined to have little detail or be largely the color of
blue sky, the verbal commands could be provide to the photographer
to raise their arm to a higher position in order to change the
viewing angle for the camera. The opposite feedback could be
provided if it is determined that there is an inadequate sky region
in the image.
[0102] It may be desirable to provide a calibration process for the
self-portrait mode. In particular, when the image capture device is
used by a single user, there will be only a very specific distance
range at which self-portrait mode will be valid, since for any
given user, the variation in distances at which that user can hold
the capture device is relatively small. Thus when the capture
device detects a face distance within that small range of
distances, it can be configured to automatically enter the
self-portrait mode. The calibration process can be selected by the
user or can be initiated during first power up so that the
appropriate measurements are taken by the capture device and stored
for future reference. In some embodiments, this calibration process
can be used to train the digital camera 10 to recognize the face of
the photographer 210, so that the self-portrait mode is entered
only when the face determination step 305 recognizes the face of
the photographer 210 in the preview image 302 captured in capture
preview image step 300.
[0103] In some embodiments, the face detection step 305 (FIG. 5) is
adapted to detect animal faces as well as human faces. This can be
useful for cases where the photographer may desire to capture a
photograph of himself with a favorite pet, or some other
animal.
[0104] In some embodiments, the photographer 210 uses the digital
camera 10 of the present invention to capture digital still images.
In other embodiments, the digital camera 10 of the present
invention is a digital video camera, or is a digital still camera
that also incorporates a video capture mode (i.e. "movie mode").
When the present invention is used in the process of capturing
digital video images, it will generally be desirable for the user
feedback be provided continuously in order to allow the user to
maintain appropriate composition during the video capture process,
and to be provided using visual feedback, rather than audio or
tactile feedback.
[0105] The invention has been described in detail with particular
reference to certain preferred embodiments thereof, but it will be
understood that variations and modifications can be effected within
the spirit and scope of the invention.
PARTS LIST
[0106] 2 flash
[0107] 4 lens
[0108] 6 adjustable aperture and adjustable shutter
[0109] 8 zoom and focus motor drives
[0110] 10 digital camera
[0111] 12 timing generator
[0112] 14 image sensor
[0113] 16 ASP and A/D Converter
[0114] 18 buffer memory
[0115] 20 processor
[0116] 22 audio codec
[0117] 24 microphone
[0118] 25 signal lights
[0119] 26 speaker
[0120] 28 firmware memory
[0121] 30 image memory
[0122] 32 image display
[0123] 34 user controls
[0124] 36 display memory
[0125] 38 wired interface
[0126] 40 computer
[0127] 42 auxiliary sensor
[0128] 44 video interface
[0129] 46 video display
[0130] 48 interface/recharger
[0131] 50 wireless modem
[0132] 52 radio frequency band
[0133] 58 wireless network
[0134] 70 Internet
[0135] 72 photo service provider
[0136] 100 color sensor data
[0137] 105 sensor noise reduction step
[0138] 110 ISO setting
[0139] 115 demosaicing step
[0140] 120 resolution mode setting
[0141] 125 color correction step
[0142] 130 color mode setting
[0143] 135 tone scale correction step
[0144] 140 contrast setting
[0145] 145 image sharpening step
[0146] 150 sharpening setting
[0147] 155 image compression step
[0148] 160 compression mode setting
[0149] 165 file formatting step
[0150] 170 metadata
[0151] 175 user settings
[0152] 180 digital image file
[0153] 185 face detection/recognition step
[0154] 210 photographer
[0155] 220 additional person
[0156] 240 image capture button
[0157] 300 capture preview image step
[0158] 302 preview image
[0159] 305 face determination step
[0160] 310 determine feedback step
[0161] 315 user feedback
[0162] 320 camera mode
[0163] 325 face distance
[0164] 400 face present test
[0165] 405 self portrait mode test
[0166] 410 within distance range test
[0167] 415 no user feedback
[0168] 420 positive user feedback
[0169] 430 digital image
[0170] 440 face
[0171] 450 photographer
[0172] 460 preferred face zone
[0173] 470 background
[0174] 500 left signal light
[0175] 510 center signal light
[0176] 520 right signal light
* * * * *