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Digital Camera Patent Abstract
A digital camera includes: a shooting unit that generates, in accordance
with a shooting operation, raw data representing a tone level of
one channel per pixel; a first generating unit that generates a
first image from the raw data; and a second generating unit that
generates a second image from the raw data more precisely than the
first generating unit with an algorithm that is different from that
of the first generating unit.
Digital Camera Patent Claims
1. A digital camera comprising: a shooting unit that generates,
in accordance with a shooting operation, raw data representing a
tone level of one channel per pixel; a first generating unit that
generates a first image from the raw data; and a second generating
unit that generates a second image from the raw data more precisely
than the first generating unit with an algorithm that is different
from that of the first generating unit.
2. The digital camera of claim 1, wherein the second generating
unit realizes, with software, a function that a dedicated circuit
configuring at least part of the first generating unit realizes.
3. The digital camera of claim 1, wherein the number of pixels
of the shooting unit corresponding to data that the second generating
unit references in order to automatically set a processing condition
for generating the second image is greater than the number of pixels
of the shooting unit corresponding to data that the first generating
unit references in order to automatically set a processing condition
for generating the first image.
4. The digital camera of claim 3, wherein the processing condition
is used in white balance correction.
5. The digital camera of claim 3, wherein the processing condition
is used in brightness correction.
6. The digital camera of claim 3, wherein the processing condition
is used in memory color correction.
7. The digital camera of claim 3, wherein the processing condition
is used in image compression.
8. The digital camera of claim 1, wherein the number of pixels
of the shooting unit corresponding to data that the second generating
unit references in order to generate one pixel of the second image
is greater than the number of pixels of the shooting unit corresponding
to data that the first generating unit references in order to generate
one pixel of the first image.
9. The digital camera of claim 1, further comprising an output
unit that stores data in a nonvolatile storage medium, wherein the
second generating unit generates, from the raw data stored in the
nonvolatile storage medium, the second image in accordance with
a development request after the shooting operation, and the output
unit stores, in the nonvolatile storage medium and in accordance
with the shooting operation, at least one of the raw data that the
shooting unit has generated and the first image that the first generating
unit has generated in accordance with the shooting operation, and
stores, in the nonvolatile storage medium and in accordance with
the development request, the second image that the second generating
unit has generated.
10. The digital camera of claim 9, further comprising a setting
unit that receives, after the shooting operation, a setting operation
of a generation condition for the second generating unit to generate
the second image, and sets the generation condition in accordance
with the setting operation, and a display control unit that displays,
on a screen and before receiving the setting operation of the generation
condition, the first image stored in the nonvolatile storage medium.
11. The digital camera of claim 1, further comprising a volatile
storage medium and an output unit that stores data in a nonvolatile
storage medium, wherein the shooting unit stores the raw data in
the volatile storage medium in accordance with the shooting operation,
the first generating unit generates, from the raw data stored in
the volatile storage medium, the first image in accordance with
the shooting operation, the second generating unit generates, from
the raw data stored in the volatile storage medium, the second image
in accordance with a development request after the shooting operation,
and the output unit stores, in the nonvolatile storage medium and
in accordance with the shooting operation, the first image that
the first generating unit has generated, and stores, in the nonvolatile
storage medium and in accordance with the development request, the
second image that the second generating unit has generated.
12. The digital camera of claim 11, further comprising a setting
unit that receives, after the shooting operation, a setting operation
of a generation condition for the second generating unit to generate
the second image, and sets the generation condition in accordance
with the setting operation, and a display control unit that displays,
on a screen and before receiving the setting operation of the generation
condition, the first image stored in the nonvolatile storage medium.
13. The digital camera of claim 1, further comprising a pre-shooting
selection unit that receives, before the shooting operation, a pre-shooting
selection operation for selecting either the first image or the
second image, and causes, in accordance with the pre-shooting selection
operation, either the first generating or the second generating
unit to generate the first image or the second image in accordance
with the shooting operation.
14. The digital camera of claim 1, further comprising a post-shooting
selection unit that receives, after the shooting operation, a post-shooting
selection operation for selecting either the first image or the
second image, and causes, in accordance with the development request
after the shooting operation, either the first generating or the
second generating unit to generate the first image or the second
image.
15. An image processing method of generating an image with a digital
camera, the method comprising: a shooting step that generates, in
accordance with a shooting operation, raw data representing a tone
level of one channel per pixel; a first generating step that generates
a first image from the raw data; and a second generating step that
generates a second image from the raw data more precisely than the
first generating unit with an algorithm that is different from that
of the first generating unit.
Digital Camera Patent Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The entire disclosure of Japanese Patent Application No.
2004-287247 (filed on Sep. 30, 2004), including the specification,
drawings and abstract, is incorporated by reference in this application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a digital camera and an
image processing method, and in particular to technology that generates
an image from raw data.
[0004] 2. Description of the Related Art
[0005] Conventional digital cameras usually execute the following
processing to store a color image in a nonvolatile storage medium
such as a removable memory. First, the digital camera AD-converts
an analog output signal from a color image sensor to generate raw
data representing a tone level of any one channel of R, G and B
in regard to the pixels of the color image sensor, and stores the
raw data in a volatile storage medium. Usually, the raw data include
the maximum image information that the digital camera can acquire
as digital data from the subject. Next, the digital camera generates,
from the raw data, an output-use image representing the tone levels
of three channels in regard to each pixel and stores the output-use
image in the volatile storage medium. In the process by which the
output-use image is generated from the raw data, pixel interpolation,
concentration conversion, resolution conversion and spatial information
conversion are administered on the basis of the shooting conditions
that the user sets before shooting. Next, the digital camera compresses
the output-use image and stores it in a nonvolatile storage medium
in a predetermined format. In this manner, in the process by which
the compressed output-use image is generated from the raw data,
various kinds of irreversible conversions are administered.
[0006] As disclosed in JP-A-11-261933 and JP-A-2004-96500, digital
cameras are known which can record raw data in nonvolatile storage
media. Digital cameras are also known which generate an output-use
image after shooting from the raw data once the raw data have been
stored in the nonvolatile storage media. Such digital cameras can
set the conditions after shooting and generate an output-use image
from the raw data.
[0007] Incidentally, conventional digital cameras generate an output-use
image with the same algorithm when generating the output-use image
in accordance with the shooting operation and when generating the
output-use image in accordance with an operation after the shooting
operation. Conventional digital cameras also give priority to speeding
up image generation processing at the expense, to a certain extent,
of image quality in order to shorten the continuous shooting interval.
Incidentally, it is not always the case that the continuous shooting
interval is important in the use environment of the digital camera.
For example, when shooting scenery, oftentimes no problems arise
even if the continuous shooting interval is long. Also, for example,
when the user is trying to generate an output-use image by reading
the raw data stored in the nonvolatile storage medium, there is
no intent on the part of the user to immediately try to shoot.
SUMMARY OF THE INVENTION
[0008] The present invention has been made in view of the above,
and it is an object thereof to provide a digital camera that can
generate an image in a short amount of time from raw data and can
also generate a high-quality image from the raw data.
[0009] (1) A digital camera according to the invention for achieving
this object comprises: a shooting unit that generates, in accordance
with a shooting operation, raw data representing a tone level of
one channel per pixel; a first generating unit that generates a
first image from the raw data; and a second generating unit that
generates a second image from the raw data more precisely than the
first generating unit with an algorithm that is different from that
of the first generating unit.
[0010] According to this invention, because the digital camera
is disposed with the second generating unit that generates an image
from the raw data more precisely than the first generating unit
with an algorithm that is different from that of the first generating
unit, a high-quality image can be generated from the raw data. According
to this invention, because the digital camera is disposed with the
first generating unit that generates an image from the raw data
more imprecisely than the second generating unit, an image can be
formed from the raw data in a short amount of time.
[0011] (2) The second generating unit may realize, with software,
a function that a dedicated circuit configuring at least part of
the first generating unit realizes.
[0012] According to this invention, when the second generating
unit generates an image, it uses more processing resulting from
software in comparison to when the first generating unit generates
an image. Thus, flexible processing corresponding to the characteristics
of the raw data becomes possible. Specifically, for example, an
image can be precisely generated in accordance with the characteristics
of the raw data by detailed conditional branch processing of a computer
program executed by a general-purpose circuit.
[0013] (3) The number of pixels of the shooting unit corresponding
to data that the second generating unit references in order to automatically
set a processing condition for generating the second image may be
greater than the number of pixels of the shooting unit corresponding
to data that the first generating unit references in order to automatically
set a processing condition for generating the first image.
[0014] According to this invention, when an image is generated
by the second generating unit from the raw data on the basis of
the automatically set processing condition, data corresponding to
more pixels are referenced in comparison to when an image is generated
by the first generating unit. Thus, a high-quality image can be
generated.
[0015] (4) The processing condition may be used in white balance
correction.
[0016] (5) The processing condition may be used in brightness correction.
[0017] (6) The processing condition may be used in memory color
correction. Memory color correction is correction that brings image
regions of color close to skin color, sky blue color and leaf green
color, for which humans have specific fixed concepts, closer to
colors corresponding to those fixed concepts.
[0018] (7) The processing condition may be used in image compression.
[0019] (8) The number of pixels of the shooting unit corresponding
to data that the second generating unit references in order to generate
one pixel of the second image may be greater than the number of
pixels of the shooting unit corresponding to data that the first
generating unit references in order to generate one pixel of the
first image.
[0020] According to this invention, when one pixel is generated
from the raw data, the second generating unit references data corresponding
to more pixels than the first generating unit. Thus, a high-quality
image can be generated.
[0021] (9) The digital camera may further comprise an output unit
that output data to a nonvolatile storage medium. The first generating
unit may generate the first image in accordance with the shooting
operation. The second generating unit may generate, from the raw
data stored in the nonvolatile storage medium, the second image
in accordance with a development request after the shooting operation.
The output unit may store, in the nonvolatile storage medium and
in accordance with the shooting operation, at least one of the raw
data that the shooting unit has generated and the first image that
the first generating unit has generated in accordance with the shooting
operation, and store, in the nonvolatile storage medium and in accordance
with the development request, the second image that the second generating
unit has generated.
[0022] According to this invention, an image is generated by the
first generating unit in accordance with the shooting operation,
and at least one of the generated image and the raw data is stored
in the nonvolatile storage medium by the output unit. Thus, the
continuous shooting interval can be reduced, and the raw data stored
in the nonvolatile storage medium can be accessed after the shooting
operation. Also, according to this invention, an image is generated
by the second generating unit and the generated image is stored
in the nonvolatile storage medium by the output unit with respect
to a development request executed after the shooting operation.
Thus, a high-quality image can be stored in the nonvolatile storage
medium.
[0023] (10) The digital camera may further comprise a setting unit
that receives, after the shooting operation, a setting operation
of a generation condition for the second generating unit to generate
the second image, and sets the generation condition in accordance
with the setting operation, and a display control unit that displays,
on a screen and before receiving the setting operation of the generation
condition, the first image stored in the nonvolatile storage medium.
[0024] According to this invention, the image stored in the nonvolatile
storage medium can be confirmed on the screen before the setting
operation of the generation condition for generating an image after
the shooting operation with the second generating unit. Thus, the
user can easily set an appropriate generation condition.
[0025] (11) The digital camera may further comprise a volatile
storage medium and an output unit that stores data in a nonvolatile
storage medium. The shooting unit may store the raw data in the
volatile storage medium in accordance with the shooting operation.
The first generating unit may generate, from the raw data stored
in the volatile storage medium, the first image in accordance with
the shooting operation. The second generating unit may generate,
from the raw data stored in the volatile storage medium, the second
image in accordance with a development request after the shooting
operation. The output unit may store, in the nonvolatile storage
medium and in accordance with the shooting operation, the first
image that the first generating unit has generated, and store, in
the nonvolatile storage medium and in accordance with the development
request, the second image that the second generating unit has generated.
[0026] According to this invention, an image is generated by the
first generating unit in accordance with the shooting operation
and the generated image is stored in the nonvolatile storage medium
by the output unit. Thus, the continuous shooting interval can be
shortened. Also, according to this invention, when a development
request is conducted after the shooting operation, an image is generated
by the second generating unit from the raw data stored in the volatile
storage medium in accordance with the shooting operation, and the
generated image is stored in the nonvolatile storage medium by the
output unit. Thus, even if the raw data are not stored in the nonvolatile
storage medium, a high-quality image can be stored in the nonvolatile
storage medium.
[0027] (12) The digital camera may further comprise a setting unit
that receives, after the shooting operation, a setting operation
of a generation condition for the second generating unit to generate
the second image, and sets the generation condition in accordance
with the setting operation, and a display control unit that displays,
on a screen and before receiving the setting operation of the generation
condition, the first image stored in the nonvolatile storage medium.
[0028] According to this invention, the image stored in the nonvolatile
storage medium can be confirmed on the screen before the setting
operation of the generation condition for generating an image after
the shooting operation with the second generating unit. Thus, the
user can easily set an appropriate generation condition.
[0029] (13) The digital camera may further comprise a pre-shooting
selection unit that receives, before the shooting operation, a pre-shooting
selection operation for selecting either the first image or the
second image, and causes, in accordance with the pre-shooting selection
operation, either the first generating or the second generating
unit to generate the first image or the second image in accordance
with the shooting operation.
[0030] According to this invention, the user can select either
the first generating unit or the second generating unit in accordance
with the status at the time of shooting. Thus, in accordance with
the status at the time of shooting, an image can be generated in
a short amount of time and in accordance with the shooting operation,
and a high-quality image can be generated in accordance with the
shooting operation.
[0031] (14) The digital camera may further comprise a post-shooting
selection unit that receives, after the shooting operation, a post-shooting
selection operation for selecting either the first image or the
second image, and causes, in accordance with the post-shooting selection
operation, either the first generating or the second generating
unit to generate the first image or the second image.
[0032] According to this invention, when an image is generated
from the raw data after the shooting operation, the user can select
either the first generating unit or the second generating unit.
Thus, in accordance with the status at the time of a development
request, an image can be generated in a short amount of time, and
an image can be precisely generated.
[0033] (15) An image processing method according to the invention
for achieving the above-described object is an image processing
method of generating an image with a digital camera, the method
comprising: a shooting step that generates, in accordance with a
shooting operation, raw data representing a tone level of one channel
per pixel; a first generating step that generates a first image
from the raw data; and a second generating step that generates a
second image from the raw data more precisely than the first generating
unit with an algorithm that is different from that of the first
generating step.
[0034] According to this invention, an image can be generated in
a short amount of time from the raw data, and an image can be precisely
generated from the raw data.
[0035] The various functions of the plural units with which the
invention is disposed are realized by a hardware resource whose
functions are specified by the configuration itself, or by a hardware
resource whose functions are specified by a program, or by a combination
of these. Also, each of the various functions of the plural units
is not limited to being realized by hardware resources that are
physically independent of each other. Also, the present invention
can not only be specified as a device, but also as a program or
a recording medium in which that program is stored.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The drawings portray embodiments reflecting the principle
of the invention in the form of simplified schematic diagrams. Many
elements and details that will be easily understood by those skilled
in the art have been omitted so that the invention does not become
unclear.
[0037] FIG. 1 is a flow chart showing an image processing method
pertaining to a first embodiment of the invention.
[0038] FIG. 2 is a block diagram showing a digital camera pertaining
to the first embodiment of the invention.
[0039] FIG. 3 is a rear view showing the digital camera pertaining
to the first embodiment of the invention.
[0040] FIG. 4 is a block diagram showing an image processing program
pertaining to the first embodiment of the invention.
[0041] FIG. 5 is a diagram showing a data structure pertaining
to the first embodiment of the invention.
[0042] FIG. 6 is a diagram showing transition between screens pertaining
to the first embodiment of the invention.
[0043] FIG. 7 is a flow chart showing an image processing method
pertaining to a second embodiment of the invention.
[0044] FIG. 8 is a flow chart showing the image processing method
pertaining to the second embodiment of the invention.
[0045] FIG. 9 is a flow chart showing the image processing method
pertaining to the second embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0046] Embodiments of the present invention will be described below
on the basis of several embodiments. Constituent elements having
the same reference numerals in the embodiments correspond to constituent
elements having those reference numerals in other embodiments. The
embodiments will be described in detail, but the present invention
is not limited to these embodiments and will be recognized as including
a very wide scope. The attached claims should be referenced to determine
the true scope of the invention.
[0047] FIG. 2 is a block diagram showing a digital still camera
(DSC) 1 according to an embodiment of the invention. FIG. 3 is a
rear view of the DSC 1.
[0048] An image sensor 14 is a color shooting element disposed
with charge transfer devices such as a CCD (Charge Coupled Device)
and photoelectric transducers discretely arranged in two-dimensional
space, and is a so-called CCD color image sensor or a CMOS color
image sensor. The image sensor 14 outputs an electrical signal corresponding
to the gray in an optical image imaged on a light-receiving surface
by lenses 10 and an aperture 12. Because the image sensor 14 is
disposed with color filters in a Bayer array per photoelectric transducer,
it outputs an electrical signal representing the tone level of any
one channel of RGB per pixel. The lenses 10 are driven by a lens
controller 11 and reciprocally move in the light axis direction.
The aperture 12 is driven by an aperture controller 13 and adjusts
the quantity of light made incident on the image sensor 14. The
time in which an electrical charge is accumulated in the image sensor
14 (shutter speed) may be controlled by a mechanical shutter, or
may be controlled electrically by the ON/OFF of a gate signal of
the image sensor 14. A sensor controller 16 outputs, to the image
sensor 14, pulse signals such as a gate signal and a shift signal
at a predetermined timing and drives the image sensor 14.
[0049] An analog front end (AFE) 18 administers AD conversion with
respect to the analog electrical signal outputted from the image
sensor 14 to generate raw data. The raw data are usually data in
which the analog electrical signals outputted from the shooting
elements are simply digitalized. Consequently, the raw data represent
the tone level of any one channel of RGB per pixel. For this reason,
the raw data are not an image and cannot be used to display an image
in which a subject is recognizable, even if the raw data are displayed
as is. However, the raw data may be data to which has been administered
some concentration conversion usually administered at the time of
image formation, such as exposure correction and white balance correction,
or may be data to which some concentration conversion has not been
administered. The raw data outputted from the AFE 18 are stored
in a RAM 32 by a RAM controller 30.
[0050] The above-described lenses 10, aperture 12, image sensor
14, lens controller 11, aperture controller 13, sensor controller
16 and AFE 18 are constituent elements of a shooting unit 15 that
configures the shooting unit described in the claims.
[0051] A color processing unit 24 serving as a first generating
unit and a second generating unit works with a control unit 37 to
administer development processing with respect to the raw data outputted
from the AFE 18. The development processing is processing that forms
an image having tone levels of three channels of RGB per pixel by
interpolating, at neighboring pixels, the tone levels of the pixels
of the raw data corresponding to the accumulated electrical charges
of the photoelectric transducers. Usually, the processing time takes
longer to reference neighboring pixels positioned in a relatively
wide range around a target pixel and calculate the tone level of
each channel of the target pixel in comparison to when referencing
neighboring pixels in a narrow range. Consequently, in the development
processing immediately after shooting, the continuous shooting interval
can be shortened by referencing neighboring pixels in a relatively
narrow range and calculating the tone level of the target pixel.
When the user does not intend to conduct a next shooting, a high-quality
image can be formed by referencing neighboring pixels of a relatively
wide range and calculating the tone level of the target pixel.
[0052] In the development processing, spatial information conversion
and various types of gray conversion such as sharpness correction,
brightness correction, contrast correction, white balance correction,
and memory color correction can be administered. For example, by
administering sharpness correction with respect to an image that
is blurry due to unsteadiness at the time of shooting, an image
that is blurry due to unsteadiness can be corrected to a sharp image.
By administering sharpness correction with respect to an image in
which scenery is represented, the image can be corrected to a sharp
image that gives the impression of being in focus in a wide area.
By administering brightness correction and contrast correction with
respect to an overexposed or underexposed image, the image can be
made to approximate an image with the correct exposure. White balance
correction is processing that adjusts the gain of RGB in accordance
with the lighting environment of the subject. By administering memory
color correction with respect to a region in which a person, a red
flower, a blue sky, or the green of trees is represented, the hue
can be corrected to a hue in which skin color can be beautifully
seen, or to a hue in which the red petals are vivid, or to a hue
in which the blue sky is clear, or to a hue in which the green of
the trees can be corrected to a lively green.
[0053] A resolution converting unit 26 serving as a first generating
unit and a second generating unit works with the control unit 37
to convert the resolution of the image to a predetermined resolution.
Specifically, for example, the resolution converting unit 26 converts
an image to a resolution corresponding to shooting conditions that
the user sets before shooting or generation conditions that the
user sets after shooting, and converts the image to a resolution
corresponding to the screen size of an LCD 36.
[0054] A compressing/extending unit 28 serving as a first generating
unit and a second generating unit compresses an image or extends
a compressed image. The compression format may be a reversible compression
format or an irreversible compression format. Specifically, for
example, the JPEG format or the JPEG 2000 format, in which DCT,
wavelet conversion, quantization, Huffman coding and run-length
coding are combined, can be adopted. The image can also be stored
in a removable memory 48 without being compressed. A quantization
table, in which the input levels and the output levels are associated,
is used for the quantization. The number of input levels corresponding
to one output level is called a quantization step width. The wider
the quantization step width is, the higher the compression ratio
becomes. It will be assumed that the compression ratio is high when
the data amount after compression is small with respect to the data
amount before compression. There is less image quality deterioration
resulting from compression when the quantization step width is narrow.
The control unit 37 can also dynamically set the quantization step
width in accordance with the image quality. Specifically, for example,
the control unit 37 can curb the suppression of tone resulting from
compression by analyzing the image and setting the quantization
step width to be small at a level corresponding to a region where
the hue changes gradually in a relatively wide range (e.g., a region
in which a blue sky with thin clouds is represented).
[0055] The above-described functions of the color processing unit
24, the resolution converting unit 26 and the compression/extension
unit 28 may be realized by dedicated circuits such as ASIC or DSP,
or may be realized by the control unit 37 executing a specific program.
[0056] A graphic controller 34 is disposed with a display control
circuit including a synthetic function, and displays, alone on the
screen of the LCD 36, a display-use image stored in a frame memory
region 96 of the RAM 32 (see FIG. 5), or superposes and displays,
on the screen of the LCD 36, a menu on the display-use image.
[0057] An operation unit 40 is disposed with a release button 50,
various types of push buttons 52, 56, 58, 60, 62 and 64 for menu
operation and the like, a lever 54, and a jog dial 66.
[0058] An external interface controller 42 communicably connects
the DSC 1 to an external system such as an unillustrated personal
computer (PC). The hard disk of an external device such as a PC
can correspond to the nonvolatile storage medium described in the
claims.
[0059] A removable memory controller 44 serving as an output unit
is an input/output mechanism that transfers the data stored in the
RAM 32 to the removable memory 48 serving as a nonvolatile storage
medium connected to a card connector 46.
[0060] A flash memory controller 39 transfers data stored in a
flash memory 38 to the RAM 32. The flash memory 38 is a nonvolatile
memory that stores an image processing program that a CPU 20 executes.
The image processing program necessary for the DSC 1 to run and
various types of data can also be stored in the flash memory 38
by downloading them via a network from a predetermined server or
by reading them from the removable memory 48.
[0061] The control unit 37 is disposed with the CPU 20, the RAM
32 and the RAM controller 30. The CPU 20 controls the units of the
DSC 1 by executing the image processing program stored in the flash
memory 38. The RAM controller 30 controls data transfer between
the RAM 32 serving as a volatile storage medium and the AFE 18,
the color processing unit 24, the resolution converting unit 26,
the compression/extension unit 28, the CPU 30, the graphic controller
34, the removable memory controller 44, and the flash memory controller
39.
[0062] FIG. 4 is a block diagram showing the logical configuration
of the image processing program that the control unit 37 executes.
[0063] A shooting control module 72 works with the shooting unit
15 when the release button 50 is depressed to generate raw data,
and stores the generated raw data in a raw buffer region 90 of the
RAM 32 (see FIG. 5).
[0064] A first generating module 80 is a program part that causes
the control unit 37 to function as a first generating unit. When
the release button is depressed, the first generating module 80
works with the color processing unit 24, the resolution converting
unit 26 and the compression/extension unit 28 to generate, from
the raw data, an output-use image serving as a first image immediately
after the raw data have been generated or in parallel with the generation.
In the development processing, a first work buffer region 92 and
a second work buffer region 94 of the RAM 32 are used. Specifically,
for example, an image immediately after development is stored in
the first work buffer region 92. An image converted from RGB to
another color space such as YCbCr is stored in the second work buffer
region 94. The output-use image may be in a format compressed by
the compression/extension unit 28 or may be in an uncompressed format.
The output-use image may also be a color image or a black-and-white
image.
[0065] A second generating module 78 is a program part that causes
the control unit 37 to function as a second generating unit. The
second generating module 78 works with the color processing unit
24, the resolution converting unit 26 and the compression/extension
unit 28 to precisely generate, with an algorithm different from
that of the first generating module 80, an output-use image serving
as a second image from the raw data. For example, the second generating
module 78 may execute pixel interpolation at the time of image formation
with an algorithm that references more neighboring pixels than the
first generating module 80. By referencing more neighboring pixels
at the time of image formation, the second generating module 78
can usually interpolate the depletion channel of the target pixel
at a more accurate tone level. The second generating module 78 may
also cause image processing such as pixel interpolation, density
conversion and spatial information conversion to be completed by
just the control unit 37. That is, this image processing may also
be executed by the control unit 37 alone executing the second generating
module 78. By executing with software this image processing executable
by the color processing unit 24 and the resolution converting unit
26 configured by dedicated circuits such as ASIC or DSP, the processing
time increases but higher image quality can be achieved at a low
cost. Conversely, when the color processing unit 24 and the resolution
converting unit 26 are configured by ASIC or DSP and execute this
processing in cooperation with the first generating module 80 immediately
after shooting, the shooting interval can be reduced.
[0066] An output module 82 is a program part that causes the control
unit 37 to function as an output unit. The output module 82 generates
a file of a predetermined format in which are stored the output-use
image and predetermined shooting information, and works with the
removable memory controller 44 to store the generated file in the
removable memory 48.
[0067] A setting module 76 is a program part that causes the control
unit 37 to function as a setting unit. The setting module 76 works
with the operation unit 40 and the graphic controller 34 to receive
a setting operation of the shooting conditions and the generation
conditions and set the shooting conditions and the generation conditions
in accordance with the setting operation. The shooting conditions
are conditions that control the characteristics of the output-use
image to be generated in response to the depression of the release
button 50. Specifically, for example, the shooting conditions are
the shutter speed, the aperture, the white balance, the scene mode,
the resolution, and the compression conditions. The generation conditions
are conditions that control the characteristics of the output-use
image, are used when generating the output-use image in accordance
with a development request from the raw data generated in response
to the depression of the release button 50, and are set after the
depression of the release button 50. Specifically, for example,
the generation conditions are the exposure correction conditions,
the white balance, the scene mode, the resolution, and the compression
conditions. The second generating module 78 and the first generating
module 80 generate the output-use image on the basis of the generation
conditions or the shooting conditions that the setting module has
set.
[0068] When the generation conditions and the shooting conditions
present in the characteristics of the raw data are to be automatically
set, such as when the gain of each channel in white balance correction
is to be set, the algorithm by which the setting module 76 sets
the generation conditions and the algorithm by which the setting
module 76 sets the shooting conditions may be different. For example,
when the gain of each channel in white balance correction is set
as a generation condition, more pixels in the raw data are sampled
in comparison to when this is set as a shooting condition. By sampling
more pixels in the raw data or the image immediately after development,
whether the region of a color close to an achromatic color is bluish
or reddish can be more accurately determined. Also, for example,
when the gain of brightness correction is set as a generation condition,
more pixels in the image immediately after development are sampled
in comparison to when this is set as a shooting condition. By sampling
more pixels in the image immediately after development, whether
the brightness should be raised or lowered can be more accurately
determined. Also, for example, when a region targeted for memory
color correction is set as a generation condition, the correction
target region and the correction parameters of that region can be
more accurately determined by sampling more pixels in the image
immediately after development in comparison to when this is set
as a shooting condition. Also, for example, when a quantization
table used in irreversible compression is set as a generation condition,
the suppression of tone resulting from compression can be curbed
by sampling the image immediately after development and dynamically
setting the quantization table according to the image characteristics.
These conditions, which are automatically set on the basis of the
generation conditions and shooting conditions that are set in accordance
with the setting operation of the user, correspond to the processing
condition described in the claims.
[0069] A display control module 74 is a program part that causes
the control unit 37 to function as a display control unit. The display
control module 74 works with the resolution converting unit 26 to
generate, from the output-use image, a display-use image with a
resolution corresponding to the screen size of the LCD 36, and stores
the display-use image in the frame memory region 96 of the RAM 32
(see FIG. 5). The display control module 74 works with the graphic
controller 34 to display, on the screen of the LCD 36, the display-use
image stored in the frame memory region 96.
[0070] FIG. 1 is a flow chart showing an image processing method
according to the DSC 1 that executes, with the control unit 37,
the above-described image processing program. The processing shown
in FIG. 1 starts when the DSC 1 moves to the shooting mode and is
repeated until the DSC 1 moves from the shooting mode to a mode
other than the shooting mode.
[0071] In step S100, the control unit 37 displays a through image
on the screen of the LCD 36 on the basis of the shooting conditions.
The shooting conditions are set in accordance with the setting operation
that the user conducts in advance. The through image is a series
of moving images obtained by shooting, at predetermined time intervals,
a subject imaged on the image sensor 14.
[0072] In step S102 and step S104, the control unit 37 executes
the shooting control module 72, and when the release button 50 is
pressed, the control unit 37 works with the shooting unit 15 to
shoot the subject on the basis of the shooting conditions and generate
raw data. The operation of pressing the release button 50 corresponds
to the shooting operation described in the claims. The generated
raw data are stored in the raw buffer region 90 of the RAM 32. The
shooting conditions used when the raw data are generated are the
focal position, the shutter speed, the aperture, and the scene mode,
for example. The focal position, the aperture, and the scene mode
are conditions that control the lens controller 11 and the aperture
controller 13. The scene mode is, for example, a human subject shooting
mode where the aperture is widened or a scenery shooting mode where
the aperture is narrowed. The shutter speed is a condition that
controls the mechanical shutter or the electrical shutter. As described
above, the raw data may be data to which white balance correction
and gamma correction have been administered.
[0073] In step S106, the control unit 37 executes the first generating
module 80 and works together with the color processing unit 24,
the resolution converting unit 26 and the compression/extension
unit 28 to generate at a high speed the display-use image and the
output-use image from the raw data on the basis of the shooting
conditions. The display-use image is an image with a resolution
corresponding to the screen size of the LCD 36. The display-use
image is stored in the frame memory region 96 of the RAM 32. The
output-use image is stored in either the first work buffer region
92 or the second work buffer region 94. The output-use image is
an image with a resolution and compression ratio corresponding to
the shooting conditions. The shooting conditions used when generating
the display-use image and the output-use image are conditions such
as white balance correction, contrast correction, color balance
correction, brightness correction, memory color correction, resolution
conversion, and compression. In step S106, the control unit 37 may
also work with the removable memory controller 44 to store the output-use
image in the removable memory 48.
[0074] It is preferable for the first generating module 80 to generate
the output-use image at a higher speed than the second generating
module 78 by working together with the dedicated circuits of the
color processing unit 24, the resolution converting unit 26, or
the compression/extension unit 28 with more processing than that
of the second generating module 78. It is also preferable for the
first generating module 80 to generate the output-use image at a
higher speed than the second generating module 78 by reducing the
number of sampling pixels or the number of sampling times to be
less than that of the second generating module 78. The continuous
shooting interval can be shortened when the first generating module
80 generates the output-use image at a higher speed than the second
generating module 78.
[0075] In step S108, the control unit 37 executes the display control
module 74 and displays the display-use image on the screen of the
LCD 36. At this time, as shown in FIG. 6(A), the control unit 37
superposes and displays, on the display-use image, a guide display
110 for guiding the receiving of the setting operation of the generation
conditions serving as a development request with a predetermined
button operation. Because the user can confirm the display-use image
in which the shooting conditions are reflected before setting the
generation conditions on the screen of the LCD 36, the user can
set appropriate generation conditions.
[0076] In step S110, step S112 and step S114, the control unit
37 sets a predetermined time in a timer and waits for the operation
of pressing the button guided by the guide display 110--for example,
a menu button 58--until the time set in the timer elapses. If the
menu button 58 is pressed during that time, the control unit 37
proceeds to the processing in step S116, and if the menu button
58 is not pressed during that time, the control unit 37 proceeds
to the processing in step S124.
[0077] In step S116, the control unit 37 displays, on the screen
of the LCD 36, a generation condition setting screen for receiving
the setting operation of the generation conditions. The selection
items of the setting operation of the generation conditions are
items that determine conditions such as sharpness correction, brightness
correction, contrast correction, white balance correction, resolution
conversion, scene mode correction, color balance correction, and
compression. The control unit 37 may cause the selection items of
the setting operation of the generation conditions to be displayed
in a hierarchical menu or in a single hierarchy menu. The generation
condition setting screen guiding the user to the higher selection
items in the hierarchy is as shown in FIG. 6(B), for example.
[0078] In step S118 and step S120, the control unit 37 executes
the setting module 76 and waits for the setting operation of the
generation conditions. When the setting operation is conducted,
the control unit 37 sets the generation conditions in accordance
with the setting operation. If the setting operation has not been
conducted, then the control unit 37 proceeds to the processing in
step S124. The setting operation of the generation conditions is
received as follows, for example. The user selects any of the selection
items of sharpness, brightness, contrast, white balance, resolution,
scene mode, color adjustment and compression ratio by rotating the
jog dial 66 in a state where the screen shown in FIG. 6(B) is displayed.
The user presses a predetermined button such as a determination
button 62 in a state where any of the selection items has been selected,
whereby a menu of selection items determining the generation conditions
in regard to the selected selection item is displayed on the screen.
[0079] The menu is as shown in FIG. 6(C), for example. The user
selects any of the selection items by rotating the jog dial 66 in
a state where the screen shown in FIG. 6(C) is shown. The user presses
a predetermined button such as the determination button 62 in a
state where any of the selection items has been selected, whereby
the control unit 37 sets the generation condition corresponding
to the selected selection item and again displays the screen shown
in FIG. 6(B). However, at this stage, the processing conditions
that are to be automatically set in accordance with the characteristics
of the raw data are not set; rather, parameters for setting the
final processing conditions are set. Specifically, for example,
when "automatic" is selected in the screen shown in FIG.
6(C), a parameter where the gain of each channel in white balance
correction is set in accordance with the sampling result of the
raw data is set. Then, at the stage when the output-use image is
to be actually generated, the optimum gain of each channel is set
on the basis of this parameter. Of course, even in this case, the
control unit 37 may reference the raw data at this stage and automatically
set the optimum processing conditions. When the user presses, for
example, a cancel button 60 in a state where the screen shown in
FIG. 6(C) is displayed, the control unit 37 again displays the screen
shown in FIG. 6(B) without setting the generation conditions. When
the user presses a predetermined button such as a function button
64 in a state where the screen shown in FIG. 6(B) is displayed,
the control unit 37 proceeds to the processing in step S122. This
operation corresponds to the development request described in the
claims.
[0080] In step S122, the control unit 37 executes the second generating
module 78 and works with the color processing unit 247, the resolution
converting unit 26 and the compression/extension unit 28 to precisely
generate the output-use image from the raw data on the basis of
the generation conditions. The output-use image is stored in either
the first work buffer region 92 or the second work buffer region
94. The second generating module 78 precisely generates the output-use
image with an algorithm that is different from that of the first
generating module 80 and overwrites the output-use image generated
by the first generating module 80 with the output-use image that
it has generated. Specifically, for example, more pixels are sampled
in regard to the raw data or the image immediately after development
as described above, more accurate processing conditions are automatically
set, and the output-use image is generated on the basis of the automatically
set processing conditions. Also, for example, an image after development
is sampled in order to set the quantization table used in irreversible
compression, and a quantization table corresponding to the characteristics
of the image is dynamically set on the basis of the sampling result.
Also, for example, more processing is executed by the control unit
37 alone, and the output-use image is generated by more detailed
conditional branch processing corresponding to the characteristics
of the image. As a result of this processing, the output-use image
overwritten by the second generating module 78 becomes a higher
quality image in comparison to the output image generated by the
first generating module 80.
[0081] The control unit 37 may also display, on the screen of the
LCD 36, an output-use image generated on the basis of the generation
conditions and receive an operation redoing the setting operation
of the generation conditions or an operation confirming the setting
content. Thus, the user can repeat the setting operation of the
generation conditions until image quality with which the user can
be satisfied is obtained, and generate an image from the raw data
on the basis of the optimum generation conditions. The first generating
module 80 may also generate an output-use image on the basis of
the shooting conditions without receiving the setting operation
of the generation conditions. Even in this case, the second generating
module 78 can generate a higher quality image in comparison to the
output image generated by the first generating module 80, by precisely
generating an output-use image with an algorithm that is different
from that of the first generating module 80.
[0082] In step S124, the control unit 37 executes the output module
82, generates a file of a predetermined format, such as an EXIF
format file, in which are stored the output-use image and shooting
information corresponding to the shooting conditions or generation
conditions, and works with the removable memory controller 44 to
store the file in the removable memory 48.
[0083] In step S126, the control unit 37 deletes the raw data stored
in the raw buffer region 90 of the RAM 32.
[0084] According to the first embodiment of the invention described
above, when an output-use image is to be generated in accordance
with an operation after the shooting operation, the output-use image
is precisely generated with an algorithm that is different from
when an output-use image is generated in accordance with the shooting
operation, whereby a high-quality output-use image can be generated.
Also, when an output-use image is to be generated in accordance
with the shooting operation, the output-use image is generated imprecisely
in comparison to when an output-use image is generated in accordance
with an operation after the shooting operation, whereby an output-use
image can be generated at a high speed.
Second Embodiment
[0085] FIG. 7 and FIG. 8 are flow charts showing an image processing
method according to a second embodiment of the invention. The processing
shown in FIG. 7 and FIG. 8 starts when the power of the DSC 1 is
turned ON and is repeated until the power of the DSC 1 is turned
OFF.
[0086] In step S200, step S202 and step S204, the control unit
37 waits for a mode switching operation and a shooting operation
while displaying a through image on the screen of the LCD 36 on
the basis of the shooting conditions. When a mode switching operation
is received, the control unit 37 proceeds to the processing in step
S214, where the DSC 1 moves to the playback mode. When the release
button 50 is pressed and a shooting operation is received, the control
unit 37 proceeds to the processing in step S206.
[0087] In step S206, the control unit 37 executes the shooting
control module 72 and works with the shooting unit 15 to shoot a
subject on the basis of the shooting conditions and generate raw
data. The generated raw data are stored in the raw buffer region
90 of the RAM 32.
[0088] In step S207, the control unit 37 determines whether either
of a raw save setting or an image save setting has been set by a
setting operation of the shooting conditions conducted before the
shooting operation. If the raw save setting has been set, the control
unit 37 proceeds to the processing in step S208, and if the image
save setting has been set, the control unit 37 proceeds to the processing
in step S210. The raw save setting is a setting for saving the raw
data in the removable memory without doing development processing.
The image save setting is a setting for saving the output-use image
generated by the development processing in the removable memory.
[0089] In step S208, the control unit 37 executes the output module
82, generates a file of a predetermined format in which are stored
the raw data and a display-use image, and works with the removable
memory controller 44 to store the file in the removable memory 48.
At this time, the control unit 37 may also execute the first generating
module 80, generate an output-use image at a high speed, and store
the output-use image in the file.
[0090] In step S210, the control unit 37 executes the first image
generating module 80 and work with the color processing unit 24,
the resolution converting unit 26 and the compression/extension
unit 28 to generate an output-use image at a high speed from the
raw data on the basis of the shooting conditions.
[0091] In step S212, the control unit 37 executes the output module
80, generates a file of a predetermined format, such as an EXIF
format file, in which are stored the display-use image, the output-use
image, and shooting information corresponding to the shooting conditions,
and works with the removable memory controller 44 to store the file
in the removable memory 48.
[0092] In step S214, the control unit 37 selects the image files
stored in the removable memory 48. The order in which the image
files are selected may be in the order of shooting or in the file
of file name.
[0093] In step S216, the control unit 37 works with the removable
memory controller 44 to store, in the frame memory region 96 of
the RAM 32, the display-use image stored in the selected image file.
[0094] In step S218, the control unit 37 executes the display control
module 74 and works with the graphic controller to display the display-use
image on the screen of the LCD 36. At this time, when raw data are
being stored in the image file being selected, the control unit
37 superposes and displays, on the display-use image, the guide
display 110 for guiding the receiving of the development request
with a predetermined button operation, as shown in FIG. 6(A).
[0095] In steps S219, step S220, and step S222, the control unit
37 waits for a mode switching operation, a next image selection
operation, and a generation conditions setting request. When the
control unit 37 receives a mode switching operation, it proceeds
to the processing in step S200, and as a result the DSC 1 moves
to the shooting mode. When the control unit 37 receives a next image
selection operation, it proceeds to the processing in step S214.
The next image selection operation is received when the user rotates
the jog dial 66, for example. When the control unit 37 receives
a generation conditions setting request, it proceeds to the processing
in step S226. The generation conditions setting request is received
when the user presses the menu button 58, for example.
[0096] In step S226, the control unit 37 displays a generation
conditions setting screen on the screen of the LCD 36.
[0097] In step S228 and step S230, the control unit waits for a
setting operation of the generation conditions. When a setting operation
is conducted, the control unit executes the setting module 76 and
sets the generation conditions in accordance with a development
request. If a development request is not conducted, the control
unit 37 proceeds to the processing in step S219.
[0098] In step S232, the control unit 37 executes the second generating
module 78 and works with the color processing unit 24, the resolution
converting unit 26 and the compression/extension 28 to precisely
generate an output-use image on the basis of the generation conditions
from the raw data stored in the selected image file.
[0099] In step S234, the control unit 37 executes the output module
80, generates a file of a predetermined format, such as an EXIF
format file, in which are stored the display-use image, the output-use
image, and shooting information corresponding to the shooting conditions
and generation conditions, and works with the removable memory controller
44 to store the file in the removable memory 48.
[0100] According to the second embodiment of the invention described
above, when an output-use image is to be generated from raw data
in the playback mode, which is not a mode where the user immediately
tries to start a shooting operation, the output-use image is precisely
generated in comparison to when the output-use image is generated
in accordance with the shooting operation, whereby a high-quality
output-use image can be generated.
Third Embodiment
[0101] FIG. 9 is a flow chart showing an image processing method
according to a third embodiment of the invention. The processing
shown in FIG. 7 starts when the power of the DSC 1 is turned ON
and is repeated until the power of the DSC 1 is turned OFF.
[0102] In step S200 to step S206, the raw data and display-use
image are generated in the same manner as in the above-described
second embodiment.
[0103] In step S308, the control unit 37 determines whether either
of a high speed priority setting or a quality priority setting has
been set by a setting operation of the shooting conditions conducted
before the shooting operation. If a high speed priority setting
has been set, then the control unit 37 proceeds to the processing
in step S310, and if a quality priority setting has been set, then
the control unit 37 proceeds to the processing in step 314. The
high speed priority setting is a setting that generates an output-use
image at a high speed from the raw data in order to shorten the
continuous shooting interval. The quality priority setting is a
setting that precisely generates an output-use image from the raw
data in order to raise the quality of the output-use image. When
the control unit 37 and the operation unit 40 receive a setting
operation of the shooting conditions conducted before the shooting
operation, they function as the pre-shooting selection unit described
in the claims.
[0104] In step S310, the control unit 37 executes the first generating
module 80 and works with the color processing unit 24, the resolution
converting unit 26 and the compression/extension unit 28 to generate
an output-use image at a high speed from the raw data on the basis
of the shooting conditions.
[0105] In step S314, the control unit 37 executes the second generating
module 78 and works with the color processing unit 24, the resolution
converting unit 26 and the compression/extension unit 28 to precisely
generate an output-use image from the raw data on the basis of the
shooting conditions.
[0106] In step S312, the control unit 37 executes the output module
80, generates a file of a predetermined format, such as an EXIF
format file, in which are stored the display-use image, the output-use
image, and shooting information corresponding to the shooting conditions,
and works with the removable memory controller 44 to store the file
in the removable memory 48.
[0107] According to the third embodiment of the invention described
above, the user can select, before the shooting operation, whether
to generate an output-use image at a high speed or precisely generate
an output-use image, can generate an output-use image at a high
speed on the basis of the setting corresponding to the selection,
and can generate a high-quality output-use image.
[0108] The high speed priority setting or the quality priority
setting may also be configured to be selectable on the generation
conditions setting screens shown in FIG. 6(B) and FIG. 6(C). In
this case, the processing shown in step S232 of FIG. 8 is executed
by either the first generating module 80 or the second generating
module 78 in accordance with the high speed priority setting or
the quality priority setting. Also, when the control unit 37 and
the operation unit 40 receive a high speed priority setting operation
or a quality priority setting operation conducted after the shooting
operation, they function as the post-shooting selection unit described
in the claims.
[0109] Combinations and sub-combinations of the various embodiments
described above will be apparent to those skilled in the art insofar
as they do not deviate from the scope and gist of the invention.
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