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Digital Camera Patent Abstract
Even if the digital camera is inexpensive without the function of
reproducing images, it can effectively use a memory capacity and
has the function of responding to quick image-capturing, and important
images can be recorded with higher priority. The digital camera
comprises a priority selection switch for selecting priority of
an image, and information about selected priority is recorded in
association with the image when the image is recorded. For example,
priority is ranked on three stages of "important", "normal",
and "memo". When a recording medium for storing image
data has an insufficient memory capacity, control is exercised such
that an image with priority lower than a newly captured image is
automatically erased to record the new image. Further, a recorded
image may be analyzed to automatically assign a low priority value
to an image that may be damaged.
Digital Camera Patent Claims
1. A digital camera capable of recording in a recording medium an
image captured through an image pickup element, the digital camera
comprising: a priority setting device which sets priority of a captured
image; and a recording device which records information indicative
of the priority set by the priority setting device in association
with the captured image when the captured image is recorded.
2. The digital camera according to claim 1, further comprising
a frame number automatic correcting device which assigns frame numbers
in order of priority by using the information indicative of the
priority.
3. The digital camera according to claim 1, wherein the priority
setting device allows a user to select priority.
4. The digital camera according to claim 3, further comprising
a frame number automatic correcting device which assigns frame numbers
in order of priority by using the information indicative of the
priority.
5. The digital camera according to claim 1, wherein the priority
setting device analyzes the captured image to determine whether
the captured image is damaged or not and automatically sets lower
priority than a normal image to a probably-damaged image.
6. The digital camera according to claim 5, further comprising
a frame number automatic correcting device which assigns frame numbers
in order of priority by using the information indicative of the
priority.
7. A digital camera capable of recording in a recording medium
an image captured through an image pickup element, the digital camera
comprising: a device which analyzes a captured image to determine
whether the captured image is damaged or not and assigns identification
information to a probably-damaged image; and a recording device
which records the identification information in association with
the captured image when the captured image is recorded.
Digital Camera Patent Description
[0001] This is a continuation of application Ser. No. 10/078,384
filed Feb. 21, 2002. The entire disclosure of the prior application
Ser. No. 10/078,384 is considered part of the disclosure of the
accompanying continuation application and is hereby incorporated
by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a technique for recording
and erasing an image that is applied to a digital camera.
[0004] 2. Description of the Related Art
[0005] As disclosed in Japanese Patent Application Publication
Nos. 2000-24479, 2000-125185, 11-187347, and 10-79914, most conventional
digital cameras include an image display device such as a liquid
crystal monitor. In such a camera with a monitor, when an unnecessary
image is erased from images recorded in a recording medium such
as a memory card, a user can select an image to be erased while
viewing reproduced images on a monitor screen.
[0006] However, recently, while advanced digital cameras have been
developed, inexpensive digital cameras have been put on the market
with functions limited by omitting the function of reproducing images,
to create a new commodity market. In general, such cameras not having
the function of reproducing images have no device for erasing recorded
images.
[0007] Further, as for the cameras having the function of reproducing
images as well, when the user wants to quickly capture an image
while an available capacity in a recording medium is insufficient,
even if the user wants to erase images of lower priorities from
recorded images, the user needs to confirm reproduced images on
a monitor to find images to be erased. Thus, the operation is inconvenient
and the user may miss an opportunity to capture an image.
SUMMARY OF THE INVENTION
[0008] The present invention has been developed in view of the
above-mentioned circumstances, and has as its object the provision
of a digital camera, by which even an inexpensive camera not having
the function of reproducing images can effectively use a recording
capacity, a camera having the function of reproducing images can
respond to quick image-capturing, and important images can be recorded
with higher priority.
[0009] In order to attain the above object, the present invention
is directed to a digital camera capable of recording in a recording
medium an image captured through an image pickup element, the digital
camera comprising: a priority setting device which sets priority
of a captured image; and a recording device which records information
indicative of the priority set by the priority setting device in
association with the captured image when the captured image is recorded.
[0010] According to the present invention, priority is set for
each image recorded in the recording medium when image-capturing,
and information indicative of priority is recorded with the image
when the image is recorded. It is possible to readily extract an
image with lower priority firstly as a candidate to be erased and
to readily arrange images in order of priority by using priority
information associated with an image.
[0011] In an embodiment of the present invention, the priority
setting device is characterized by allowing the user to select priority.
The user operates the priority setting device before image-capturing
to optionally select priority of a captured image.
[0012] According to another embodiment of the present invention,
the priority setting device is characterized by analyzing the captured
image to determine whether the captured image is damaged or not
and automatically setting lower priority than a normal image to
an image that may be damaged.
[0013] It is hardly worth storing a damaged image (failed image)
such as an image blurred by camera-shake and an image having an
unsuitable amount of light exposure. Therefore, the captured image
is analyzed, whether the captured image is damaged or not is determined,
and information indicative of low priority is automatically assigned
to the captured image that may be damaged. Thus, it is possible
to readily discriminate a damaged image and a normal image by automatically
setting priority. Of course, a camera may include the combination
of a manual priority setting device, which allows the user to optically
select priority, and an automatic priority setting device using
image analysis.
[0014] As a pattern of use of the information indicative of priority
associated with the image, the digital camera may further comprise
a control device a control device which, if the recording medium
has an insufficient recording capacity when a new image is captured,
erases an image recorded in the recording medium with priority lower
than the new image and records the new image in the recording medium.
[0015] Even when an available capacity is insufficient in the recording
medium, by setting high priority before image-capturing, an image
with lower priority is erased from recorded images, and a new image
is recorded. Thus, it is possible to quickly respond to an opportunity
for capturing an image and to effectively use a recording capacity
of an inexpensive camera not having the function of reproducing
images.
[0016] As another pattern of use of priority information, the digital
camera may further comprise a frame number automatic correcting
device which assigns frame numbers in order of priority by using
the information indicative of the priority. Hence, it is possible
to readily perform file management such as sorting files in order
of priority. An important image can be firstly viewed and transferred.
[0017] The present invention is also directed to a digital camera
capable of recording in a recording medium an image captured through
an image pickup element, the digital camera comprising: a device
which analyzes a captured image to determine whether the captured
image is damaged or not and assigns identification information to
a probably-damaged image; and a recording device which records the
identification information in association with the captured image
when the captured image is recorded.
[0018] As a pattern of use of the identification information, for
example, control is exercised such that when the recording medium
has an insufficient recording capacity, an image that may be damaged
is erased and a newly captured image is recorded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The nature of this invention, as well as other objects and
advantages thereof, will be explained in the following with reference
to the accompanying drawings, in which like reference characters
designate the same or similar parts throughout the figures and wherein:
[0020] FIG. 1 is a perspective view showing a digital camera according
to an embodiment of the present invention;
[0021] FIG. 2 is a block diagram showing the configuration of the
digital camera of the present embodiment;
[0022] FIG. 3 is a flowchart showing the controlling steps of the
digital camera according to the present embodiment;
[0023] FIG. 4 is a block diagram showing a main configuration of
a digital camera according to another embodiment of the present
invention;
[0024] FIG. 5 is a flowchart showing the controlling steps of the
digital camera shown in FIG. 4;
[0025] FIG. 6 is a flowchart showing the controlling steps of automatically
rewriting frame numbers; and
[0026] FIG. 7 is an explanatory drawing showing the content of
the operation of automatically rewriting frame numbers.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] Hereunder preferred embodiments for a digital camera of
the present invention will be described in accordance with the accompanied
drawings.
[0028] FIG. 1 is a perspective view showing a digital camera according
to an embodiment of the present invention. The camera 10 includes
a taking lens 12 and a shutter button 14, and further includes a
switch for selecting priority of an image (hereinafter, referred
to as priority selection switch) 16. The priority selection switch
16 has a sliding switch for specifying priority on three stages
of "important", "normal", and "memo".
A user can freely set a rank indicative of priority by operating
the switch 16.
[0029] In normal image-capturing, priority is set at "normal"
before image-capturing. When an image with lower priority is captured,
"memo" is selected. When a particularly important image
is captured, "important" is selected before image-capturing.
In the present embodiment, priority is set on three stages. Priority
may be ranked on two stages or more three stages.
[0030] Priority is added as information for identifying an image.
The contents of image processing (the number of pixels, compressibility,
and so on) are not affected by the order of priority. Moreover,
the camera 10 does not have an image display device such as a liquid
crystal monitor, so that the camera itself does not have the function
of reproducing captured images.
[0031] FIG. 2 is a block diagram showing the digital camera of
the present embodiment. A CCD image sensor (hereinafter, referred
to as a CCD) 20, which serves as an image pickup element, is provided
at the rear of the taking lens 12. Photosensors are arranged horizontally
on a light-receiving surface of the CCD 20. An image of a subject
that is formed on the light-receiving surface of the CCD 20 through
the taking lens 12 is converted by the photosensors to signal charge
whose amount is determined by an incident light quantity. Additionally,
the CCD 20 has a so-called electronic shutter function, which controls
the charge storing time (shutter speed) of the photosensors according
to the timing of a shutter gate pulse.
[0032] Signal charges stored in the photosensors are sequentially
read as voltage signals (image signal) corresponding to signal charge
based on a pulse supplied from a CCD driver 22, and the signals
are transmitted to an analog signal processing section 24. The analog
signal processing section 24 includes signal processing circuits
such as a sampling hold circuit, a color separation circuit, and
a gain adjustment circuit. In the analog signal processing section
24, correlation double sampling (CDS) is performed, color separation
is performed to generate color signals of R, G and B, and signal
levels of the color signals are adjusted (pre-white balance).
[0033] Signals outputted from the analog signal processing section
24 are converted to digital signals in an A/D converter 26, and
then, the signals are transmitted to a digital signal processing
section 30 via a bus 28. Timing signals are supplied to the CCD
driver 22, the analog signal processing section 24, and the A/D
converter 26 from a timing generator (TG) 32. These timing signals
synchronize the circuits.
[0034] The digital signal processing section 30 functions as an
image processing device including a luminance/color-difference signal
generating circuit, a gamma correction circuit, a sharpness correction
circuit, a contrast correction circuit, and a white-balance correction
circuit. Image data captured in response to the push of the shutter
button 14 is converted to a luminance signal (Y signal) and a color-difference
signal (CrCb signal) in the digital signal processing section 30,
and the signals are subjected to a predetermined operation such
as gamma correction. And then, the signals are stored in a memory
34. Data stored in the memory 34 is compressed in a predetermined
form such as JPEG (Joint Photographic Experts Group) in a compressing
section 36 and is recorded in a memory card 40 via a card interface
38.
[0035] In the camera 10 of the present embodiment, for example,
smart media (Solid-State Floppy Disk Card) is used as a device for
storing image data. The form of a recording medium is not limited
to the above. A PC card, a compact flash, a magnetic disk, an optical
disk, a magneto-optical disk, and a memory stick are also applicable.
Various media are available which can read and write according to
an electronic, magnetic, or optical method, or combined methods.
A signal processing device and an interface that correspond to a
used medium are used. Further, a device for storing images is not
limited to a removable medium that can be attached and detached
to the camera 10. A recording medium built in the camera 10 (internal
memory) is also applicable. When images are stored in the internal
memory, a communication interface is provided for transferring data
to an external device such as a personal computer.
[0036] A control unit 42 is a block including a CPU and periphery
circuits thereof, and has programs required for controlling the
operation of the camera 10. In response to input signals received
from the shutter button 14, the priority selection switch 16, and
other operating sections, the control unit 42 controls the operation
of the corresponding circuit and performs image-capturing control
such as autofocus (AF) control, autoexposure (AE) control, and recording
control.
[0037] Namely, the control unit 42 performs various computations
such as focus evaluating computation and AE computation based on
image data captured in response to a half push of the shutter button
14, and the control unit 42 controls a lens driving section (not
shown) based on the computation result to shift the taking lens
12 to a focused position. Meanwhile, the control unit 42 controls
a diaphragm mechanism (not shown) and the charge storing time of
the CCD 20. Besides, the AF function may be omitted by using a taking
optical system having a great depth of field. Further, the control
unit 42 determines a recording capacity (memory capacity) of the
memory card 40 and controls the recording operation.
[0038] The following will discuss the operation of the camera 10
configured thus. FIG. 3 is a flowchart showing the controlling steps
of the camera 10. When the camera 10 is started (step S110) and
a release signal is turned on at the push of the shutter button
14 (step S112), an image-capturing is started. Subsequently, the
state of the priority selection switch 16 is determined (step S114).
[0039] When "normal" is selected by the priority selection
switch 16, the flow proceeds to step S116, "2" is set
as a value indicative of priority, and the value is associated with
image data of the image-capturing. When "memo" is selected
in step S114, the flow proceeds to step S118, "1" is set
as a value indicative of priority, and the value is associated with
image data of the image-capturing. When "important" is
selected in step S114, the flow proceeds to step S120, "3"
is set as a value indicative of priority, and the value is associated
with image data of the image-capturing.
[0040] After step S116, step S118, or step S120, the flow proceeds
to step S140. In step S140, a memory capacity of the memory card
40 is determined. When a sufficient memory capacity is available
for recording a captured image, the image is recorded in the memory
card 40 (step S142). At this moment, a value indicative of priority
is recorded with the image.
[0041] When determination is made that a memory capacity is insufficient
in step S140, the flow proceeds to step S144. In step S144, determination
is made whether the memory card 40 stores an image with priority
lower than a captured image (image to be recorded). When an image
with priority "3" is captured while the memory card 40
stores at least an image with priority "2" or "1",
or when an image with priority "2" or "3" is
captured while the memory card 40 stores only images with priority
"1", determination is YES in step S144.
[0042] When YES determination is obtained in step S144, the flow
proceeds to step S150, an image with lower priority is erased, and
the flow returns to step S140. When a sufficient capacity is obtained
for recording a new image by erasing an image in step S150, determination
of "memory capacity available (OK)" is obtained in step
S140, and the new image is recorded (step S142).
[0043] In step S150, when an image is erased but a sufficient capacity
is not obtained for recording a new image, determination of "memory
capacity shortage (NG)" is obtained in step S140, and another
image is erased after determination of step S144.
[0044] In step S144, when an image to be erased does not exist
and determination is NO, a new image cannot be recorded. Thus, the
flow proceeds to step S152. In step S152, display is provided to
notify that no capacity is available in the memory card 40 (or internal
memory) and to recommend the user to exchange the card or transfer
image data. As a device for displaying that no capacity is available,
for example, an indicator lamp such as a light-emitting diode (LED)
may be provided on the camera 10, a small liquid crystal indicator
(character liquid crystal display) capable of displaying characters
and symbols may be provided, or the indicators may be combined.
[0045] According to the camera 10 of the present embodiment, even
in the case where no capacity is available in the memory card 40
while images with a priority value "1" or "2"
are recorded in the memory card 40, since the shutter button 14
is pushed after "important" is selected by the priority
selection switch 16, image data with priority "1" or "2"
is automatically erased and a new image with priority "3"
is recorded. When images of priority "1" and "2"
are mixed in the card, an image with lower priority is erased first.
[0046] Since a recorded image is erased and a new image is recorded
according to priority, even for the inexpensive camera 10 not having
the reproducing function, it is possible to effectively use a remaining
capacity of the memory card 40. Thus, the camera 10 can quickly
respond to an opportunity for capturing an image.
[0047] Although the above explanation discussed the embodiment
in which the user optionally specifies image priority, priority
may be set automatically. Hereinafter, an embodiment of automatic
priority setting will be discussed as another embodiment of the
present invention.
[0048] FIG. 4 is a block diagram showing a main configuration of
a digital camera according to another embodiment of the present
invention. The camera 60 is mainly composed of the taking lens 12,
the CCD 20, a video signal processing device 62, an image analysis
device 64, a recording device 66, a control device 68, and the shutter
button 14. The video signal processing device 62 is a block for
processing an image signal outputted from the CCD 20 to generate
image data, and corresponds to a block including the analog signal
processing section 24, the A/D converter 26, the digital signal
processing section 30, and the memory 34 of FIG. 2. The image analysis
device 64 of FIG. 4 is an image processing section for analyzing
image data obtained in the video signal processing device 62, and
is included in the digital signal processing section 30 of FIG.
2. The recording device 66 of FIG. 4 is a device for recording captured
images with information (values) about priority, and corresponds
to the compressing section 36, the card interface 38, and the memory
card 40 of FIG. 2. Certainly, an internal memory may be used instead
of a removable medium.
[0049] The camera 60 of FIG. 4 analyzes recorded images in the
image analysis device 64 and determines whether the images are damaged
or not. And then, regarding an image that may be damaged, a priority
rank is automatically determined and a priority value is set according
to the rank.
[0050] FIG. 5 is a flowchart showing the controlling steps of the
camera 60. In FIG. 5, the steps shared by FIG. 3 are indicated by
the same step numbers and the description thereof is omitted. To
an image captured when the release button 14 is turned on (step
S112), a priority value A=3 is initially assigned (step S126).
[0051] Subsequently, image analysis is performed on the image to
determine whether a camera-shake is larger than a predetermined
value (a predetermined determination reference value for determining
shift) or not (step S130). A camera-shake is determined by detecting
an edge of the image and determining whether the edge is shifted
in one direction. In step S130, when determination is YES, the flow
proceeds to step S132, 1 is subtracted from the priority value A,
and the subtraction result is used as a new priority value A. After
step S132 or when determination is NO in step S130, the flow proceeds
to step S134.
[0052] In step S134, determination is made whether a quantity of
light exposure is normal or not based on the image analysis. For
example, luminance distribution of the entire screen is determined,
and when a part having a luminance of 100% (a part where a gradation
value indicating luminance is maximum, that is, a white void) or
a part having a luminance close to 0% (a part where a gradation
value indicating luminance is small and the part is viewed as black)
makes up a predetermined ratio or more (e.g., 30% or more) on the
entire screen, overexposure or underexposure is determined.
[0053] In step S134, when a quantity of light exposure is not normal
(NO determination), the flow proceeds to step S136, 1 is subtracted
from the priority value A, and the subtraction result is used as
a new priority value A. After step S136, or when determination is
made that a quantity of light exposure is normal in step S134, the
flow proceeds to step S140. The operations after step S140 are the
same as those of FIG. 3.
[0054] As shown in FIG. 5, a captured image is determined by image
analysis and priority is automatically determined according to a
level of the image that may be damaged. Thus, it is possible to
firstly extract a failed image as an image to be erased. According
to this embodiment, the priority selection switch 16 of FIG. 1 may
be omitted, and it is also preferable to use the priority selection
switch 16 in combination.
[0055] For example, according to a priority value selected in the
priority selection switch 16, the result of image analysis is reflected
to automatically correct the priority value. In this case, according
to an embodiment, a priority value of an image captured after the
priority selection switch 16 selects "important" is never
corrected, so as to respect the intention of the user.
[0056] A method for automatically setting information indicative
of priority by a camera is not limited to the above. The following
method is also applicable: information about an image-capturing
location is obtained using GPS (Global Positioning System), determination
is automatically made whether the image-capturing location is an
environment of daily life, and high priority is placed on an image
captured in a location other than the environment of daily life.
[0057] The use of information indicative of priority is not limited
to securing an available capacity obtained by automatically extracting
an image to be erased. It is also possible to use priority information
to arrange images (frames) in order of priority, thereby readily
managing an image file after recording.
[0058] Normally, a digital camera automatically assigns consecutive
frame numbers (file numbers) in order of image-capturing. The camera
10 according to an embodiment of the present invention can sort
frames in order of priority using priority information to automatically
change frame numbers. Besides, the frame numbers are used as file
names. For example, a file name of "frame number =0001"
is "DSCF0001.JPG", in which a prefix character string
"DSCF" and an extension ".JPG" are added.
[0059] FIG. 6 is a flowchart showing the controlling steps. In
FIG. 6, the steps shared by FIG. 3 are indicated by the same reference
numerals and the description thereof is omitted. In FIG. 6, after
the step of determining a priority value according to the setting
of the priority selection switch 16 (step S116, step S118, or step
S120), the flow proceeds to step S160. In step SI60, images with
priority lower than selected priority are shifted by +1 in frame
number, and a new image is recorded at the front of the shifted
images.
[0060] The above operation will be discussed using FIG. 7. The
memory card 40 has already recorded a plurality of images with priority
values of "3(important)", "2(normal)", and "1(memo)".
At this moment, when a new image with priority "3" is
captured, images with priority lower than the above image, that
is, images with priority 2 or less are shifted by +1 in frame number.
An image with a frame number "x" is changed to an image
with a frame number "x+1", and the subsequent frame number
is also shifted by +1. And then, a frame number at the front ("x"
in FIG. 7) that is made vacant by shifting the frame numbers by
+1 is allocated to the newly recorded image.
[0061] The frame numbers are determined in order of priority according
to the rule of step S160 shown in FIG. 6. Therefore, file management
is readily performed when image data is transferred to an external
device such as a personal computer, so that important data can be
firstly transferred and important images can be firstly viewed.
Further, after the step S134 or step S135 of FIG. 5, the operation
of step S160 of FIG. 6 may be performed instead of the operations
of the step S140 to step S152 (not shown).
[0062] Furthermore, it is also possible to combine the controlling
methods of FIGS. 3 and 5 and the above-mentioned operation of rewriting
frame numbers. In this case, in step S142 of FIGS. 3 and 5, the
operation of step S160 in FIG. 6 is applied when an image is recorded.
[0063] Although the above description discussed the embodiment
in which frame numbers are rewritten according to priority values,
the range of use of frame numbers may be changed for each priority
rank. For example, frame numbers "0001" to "0999"
are assigned to "important" images, frame numbers "1001"
to "1999" are assigned to "normal" images, and
frame numbers "2001" to "2999" are assigned
to "memo" images. Hence, priority can be recognized by
a front digit of a frame number, and files can be sorted using ordinary
application software, thereby readily managing files. Moreover,
folders may be recorded respectively for priority ranks.
[0064] Although the above description discussed recording of still
images, the present invention is not limited to this and is also
applicable to record moving images.
[0065] The following will discuss variations of the above-mentioned
embodiments.
[0066] (Variation 1) It is also preferable to add a device for
editing priority information, which is determined by user selection
using the priority selection switch 16 or automatic priority setting
using image analysis, and which is recorded together with images.
According to a camera with such an editing device, priority information,
which has been recorded in image recording, can be freely changed
by the user after recording.
[0067] (Variation 2) As discussed in FIG. 1, the present invention
is quite effective when it is applied to a camera not having an
image display device such as a liquid crystal monitor. However,
the application of the present invention is not limited to the above
and is also applicable to a camera having the function of reproducing
images. In the case of a camera having the function of reproducing
recorded images on an image display device (camera with a monitor),
by assigning lower priority in advance to images to be erased, it
is possible to respond to quick image-capturing and to prevent an
important image from being erased by mistake. Further, according
to the configuration additionally comprising a device for editing
priority information, priority information can be readily changed
by reexamining priorities of images while viewing reproduced images
after image-capturing.
[0068] (Variation 3) In the above-mentioned embodiment, a priority
rank is divided into three stages of "important">"normal">"memo".
The classification is not limited to the above. For example, priority
may be ranked on "work">"private">"others
(memo)", "portrait">"landscape">"others"
based on a target (image-capturing mode), or "travel">"normal">"others".
The number of priority ranks and the names of the ranks can be optionally
changed.
[0069] As described above, according to the embodiment of the present
invention, when an image is recorded, information indicative of
priority of the image is recorded in association with the image.
Thus, with priority information, control can be exercised to automatically
erase an image with lower priority and arrange images in order of
priority.
[0070] According to the embodiment of the present invention, a
recorded image can be erased and a new image with higher priority
can be recorded according to priority. Thus, it is possible to respond
to quick image-capturing. A recording capacity can be effectively
used by applying the present invention to an inexpensive camera
not having the function of reproducing images.
[0071] Also, when the present invention is applied to a camera
having the function of reproducing images, by assigning lower priority
in advance to images to be erased, it is possible to respond to
quick image-capturing and to prevent an important image from being
erased by mistake.
[0072] It should be understood, however, that there is no intention
to limit the invention to the specific forms disclosed, but on the
contrary, the invention is to cover all modifications, alternate
constructions and equivalents falling within the spirit and scope
of the invention as expressed in the appended claims. |