Digital Camera Patent AbstractA digital camera includes an image sensor. Image data of an object
photographed by the image sensor is subjected to a color adjustment
on the basis of color adjustment values set to a signal processing
circuit. If a shutter button is operated, an image file including
the image data and the color adjustment values set to the signal
processing circuit is recorded into a memory card. When the memory
card is attached to a PC, and a color reproduction characteristic
of the image data included in the image file is adjusted by the
PC, the color adjustment values are, in company therewith, also
changed. When the memory card is returned to the digital camera,
a change in the color adjustment values is detected by a CPU, and
the color adjustment values set to the signal processing circuit
is overwritten by the color adjustment values included in the image
file.
Digital Camera Patent ClaimsWhat is claimed is:
1. A digital camera that subjects a photographed image signal to
an image quality adjustment process on the basis of an image quality
adjustment value set to a memory, comprising: a recorder for recording
into a recording medium an image file including the photographed
image signal which has been subject to the image quality adjustment
process and the image quality adjustment value set to said memory
upon receipt of a recording instruction, wherein said image quality
adjustment value stored on said recording medium is capable of being
transferred with said image file to another device; a determiner
for determining whether or not the image quality adjustment value
included in said image file is changed; and an overwriter for overwriting
the image quality adjustment value set to said memory with the image
quality adjustment value included in said image file depending upon
a determination result of said determiner so as to reflect a new
written image quality adjustment value on the image quality adjustment
process which is directed to a photographed image signal to be obtained
after an over-writing process.
2. A digital camera according to claim 1, wherein said determiner
determines that said image quality adjustment value is changed when
a specific marker is included in said image file.
3. A digital camera according to claim 1, wherein a plurality of
the image quality adjustment values which respectively correspond
to a plurality of image quality adjustment modes are set to said
memory, said recorder includes a creator for creating a file header
including image quality adjustment mode information and the image
quality adjustment value, and a file recorder for recording into
said recording medium an image file including the file header and
the photographed image signal, and said overwriter includes a specifier
for specifying the image quality adjustment value to be overwritten
from said memory on the basis of the image quality adjustment mode
information included in the file header, an image quality adjustment
value overwriter for overwriting the image quality adjustment value
specified by said specifier by the image quality adjustment value
included in said file header.
4. A digital camera according to claim 1, wherein said recording
medium is detachable.
5. A digital camera according to claim 1, wherein said another
device is a computer.
6. An image quality control method of a digital camera that subjects
a photographed image signal to an image quality adjustment process
on the basis of an image quality adjustment value set to a memory,
comprising the steps of: (a) recording into a recording medium an
image file including the photographed image signal which has been
subject to the image quality adjustment process and the image quality
adjustment value set to said memory upon receipt of a recording
instruction, wherein said image quality adjustment value stored
on said recording medium is capable of being transferred with said
image file to another device; (b) determining whether or not the
image quality adjustment value included in said image file is changed;
and (c) overwriting the image quality adjustment value set to said
memory with the image quality adjustment value included in said
image file depending upon a determination result of said step (b)
so as to reflect a new written image quality adjustment value on
the image quality adjustment process which is directed to a photographed
image signal to be obtained after an over-writing process.
7. An image quality control method according to claim 6, wherein
said another device is a computer.
8. A digital camera, comprising: an imaging device for creating
an object scene image; a memory for storing an image quality adjusting
value; an adjuster for adjusting an image quality of the object
scene image created by said imaging device based on the image quality
adjusting value stored in said memory; a recorder for recording
to a recording medium an image file including the object scene image
having the image quality adjusted by said adjuster and the image
quality adjusting value stored in said memory in case of accepting
a recording instruction; an accepter for accepting a selecting operation
to select a specific image file including a specific image quality
adjusting value changed by an external apparatus from among image
files recorded in said recording medium in association with a setting
of a specific mode; a reproducer for reproducing the object scene
image included in the specific image file selected by said selecting
operation; and an over-writer for writing the specific image quality
adjusting value included in the specific image file noted by said
reproducer over the image quality adjusting value stored in said
memory so as to reflect the specific image quality adjusting value
on an adjusting process of said adjuster which is directed to an
object scene image to be created by said imaging device after an
over-writing process.
9. A digital camera according to claim 8, further comprising a
determiner for determining whether or not the image file selected
by said selecting operation is the specific image file, wherein
said over-writer carries out a writing process when a determination
result of said determiner is affirmative.
10. A digital camera according to claim 9, wherein said reproducer
carries out a reproducing process without respect to the determination
result of said determiner.
11. A digital camera according to claim 9, wherein the specific
image file has a specific marker, and said determiner carries out
a determining process in reference to the specific marker.
12. A digital camera according to claim 8, wherein said memory
stores a plurality of the image quality adjusting values respectively
corresponding to a plurality of image quality adjusting modes, said
recorder includes a creator for creating a file header including
image quality adjusting mode information and an image quality adjusting
value which are corresponding to each other, and a file recorder
for recording to said recording medium the image file including
the file header and the object scene image, and said over-writer
includes a specifier for specifying an image quality adjusting value
to be overwritten from among the plurality of image quality adjusting
values stored in said memory based on the image quality adjusting
mode information included in the file header, and an image quality
adjusting value over-writer for writing the image quality adjusting
value included in the file header over the image quality adjusting
value specified by said specifier.
13. A digital camera according to claim 8, wherein the object scene
image included in the specific image file has an image quality based
on the specific image quality adjusting value.
14. A digital camera according to claim 8, wherein said recording
medium is detachable, and said external apparatus is an apparatus
capable of attaching said recording medium. Digital Camera Patent DescriptionBACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a digital camera. More specifically,
the present invention relates to a digital camera that subjects
a photographed image signal to an image quality adjustment on the
basis of an image quality adjustment value set to a memory.
2. Description of the Prior Art
An image quality changes depending upon what image adjustments
are subjected to an image signal. This resulted in a conventional
digital camera, in which the image signal outputted from an image
sensor is subjected to an image quality adjustment on the basis
of an image quality adjustment value stored in a memory, and the
image quality adjustment value is changeable on a monitor screen.
In a background of an image quality adjustment menu, a through image
(real time moving image) is displayed, and if the image quality
adjustment value is changed, the image quality of the through image
is changed. However, a monitor provided on the digital camera is
limited in size, and only the image in low resolution is displayable
on the monitor, thus not possible to exactly adjust the image quality.
SUMMARY OF THE INVENTION
Therefore, it is a primary object of the present invention to provide
a digital camera capable of exactly adjusting an image quality of
a photographed image.
According to the present invention, a digital camera that subjects
a photographed image signal to an image quality adjustment on the
basis of an image quality adjustment value set to a memory, comprises:
a recorder for recording into a recording medium an image file including
the photographed image signal and the image quality adjustment value
set to the memory upon receipt of a recording instruction; a determiner
for determining whether or not the image quality adjustment value
included in the image file is changed; and an overwriter for overwriting
the image quality adjustment value set to the memory by the image
quality adjustment value included in the image file depending upon
a determination result of the determiner.
The photographed image signal is subjected to the image quality
adjustment on the basis of the image quality adjustment value set
to the memory. Upon receipt of the recording instruction, the image
file including the photographed image signal and the image quality
adjustment value set to the memory is recorded into the recording
medium by the recorder. Whether or not the image quality adjustment
value included in the image file is changed is determined by the
determiner. The overwriter overwrites the image quality adjustment
value set to the memory by the image quality adjustment value included
in the image file depending upon the determination result of the
determiner.
The image quality adjustment value, together with the photographed
image signal, is stored in the image file, thus becoming possible
to adjust an image quality of the photographed image signal and
change the image quality adjustment value in response to the adjustment
by fetching the image file into a PC, for example. When the image
quality adjustment value is thus changed, the image quality adjustment
value stored in the memory is overwritten by the changed image quality
adjustment value. Due to this, it is possible to reflect the changed
image quality adjustment value on the image quality adjustment of
the photographed image signal. That is, it becomes possible to exactly
adjust the image quality of the photographed image signal as a result
of a mechanism recording the image quality adjustment value into
the image file, and a mechanism overwriting the image quality adjustment
value set to the memory by the image quality adjustment value within
the image file.
The determiner preferably determines that the image quality adjustment
value is changed when a specific marker is included in the image
file. It is possible to determine whether or not the image quality
adjustment value is changed on the basis of the specific marker
if the PC is to write the specific marker into the image file at
a time of changing the image quality adjustment value.
In a case that a plurality of the image quality adjustment values
which respectively correspond to a plurality of image quality adjustment
modes are set to the memory, the recorder creates a file header
including image quality adjustment mode information and the image
quality adjustment value, and records into the recording medium
the image file including the file header and the photographed image
signal. Furthermore, the overwriter specifies the image quality
adjustment value to be overwritten from the memory on the basis
of the image quality adjustment mode information included in the
file header, and overwrites the specified image quality adjustment
value by the image quality adjustment value included in the file
header. This makes it possible to prepare a plurality of the preferred
image quality adjustment values in the memory.
It is noted that if the recording medium is rendered detachable,
there is no need any longer that the digital camera and the PC are
connected by a cable, or the like. This enhances operability.
The above described objects and other objects, features, aspects
and advantages of the present invention will become more apparent
from the following detailed description of the present invention
when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing one embodiment of the present
invention;
FIG. 2 is a block diagram showing one example of a signal processing
circuit;
FIG. 3 is an illustrative view showing one example of a reference
value table;
FIG. 4 is an illustrative view showing one example of a target
value table;
FIG. 5 is an illustrative view showing one example of a distributed
state of reference values and target values;
FIG. 6 is an illustrative view showing another example of a distributed
state of the reference values and the target values;
FIG. 7 is a flowchart showing one portion of an operation of an
area determination circuit;
FIG. 8 is an illustrative view showing one portion of an operation
of the FIG. 1 embodiment;
FIG. 9 is an illustrative view showing another portion of the operation
of the FIG. 1 embodiment;
FIG. 10 is an illustrative view showing the other portion of the
operation of the FIG. 1 embodiment;
FIG. 11 is a flowchart showing one example of an operation of a
CPU in a photographing mode;
FIG. 12 is a flowchart showing one example of an operation of the
CPU in a reproduction mode;
FIG. 13 is a flowchart showing one example of structure of a personal
computer; and
FIG. 14 is a flowchart showing one portion of an operation of the
personal computer shown in FIG. 13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a digital camera 10 in this embodiment includes
a focus lens 12. An optical image of an object is incident on a
light-receiving surface of an image sensor 14 via the focus lens
12. On the light-receiving surface, a camera signal (raw image signal)
corresponding to the incident optical image is generated by photoelectronic
conversion. It is noted that the light-receiving surface is covered
by a color filter of the Bayer pattern (not shown), and each pixel
signal forming the camera signal has only any one of color components
R, G, and B.
If a photographing mode is selected by a photographing/reproducing
change switch 44, a process instruction is applied from a CPU 38
to a timing generator (TG) 16, and the image sensor 14 is driven
by the TG 16. The image sensor 14 repeatedly reads out the camera
signal generated by the photoelectronic conversion at a predetermined
frame rate. The read camera signal of each frame is converted into
a digital signal by an A/D converter 20 via a well-known noise removal
and a level adjustment in a CDS/AGC circuit 18.
A signal processing circuit 22 subjects camera data of each frame
outputted from the A/D converter 20 to signal processes such as
color separation, a white balance adjustment, a color adjustment
(color tone correction), a YUV conversion, and so on in response
to a process instruction from the CPU 38 so as to generate image
data formed of a luminance component (Y data) and color difference
components (U data, V data). Generated image data is applied to
a memory control circuit 24, and written into an image data storing
area 26a of an SDRAM 26 by the memory control circuit 24.
A video encoder 28 causes the memory control circuit 24 to read
out the image data in the image data storing area 26a in response
to a process instruction from the CPU 38. Then, the read image data
of each frame is encoded into a composite image signal in an NTSC
format, and the encoded composite image signal is supplied to a
monitor 30. On the monitor 30, a through image of the object is
displayed.
If a shutter button 40 is depressed by an operator, the CPU 38
applies a compression instruction to a JPEG CODEC 32. The JPEG CODEC
32 causes the memory control circuit 24 to read out one frame of
the image data stored in the image data storing area 26a, and applies
a JPEG compression to the read image data. Upon obtaining the compressed
image data, the JPEG CODEC 32 applies generated compressed image
data to the memory control circuit 24. The compressed image data
is stored into a compressed data storing area 26b by the memory
control circuit 24.
Upon completion of a storing process of the compressed image date,
the CPU 38, in addition to reading out the compressed image data
from the compressed data storing area 26b through the memory control
circuit 24, creates by itself header information (Exif information)
including reference values, target values, and mode information
described later. Then, the image file in which the header information
and the compressed image data are stored is recorded into a memory
card 36 through an I/F circuit 34. It is noted that the memory card
36 is a detachable non-volatile recording medium, and becomes accessible
by the CPU 38 when attached to a slot (not shown).
When a reproduction mode is selected by the photographing/reproducing
change switch 44, the CPU 38 detects the image file to be reproduced
from the memory card 36, reads out the compressed image data stored
in the image file through the I/F circuit 34, and stores the read
compressed image data into the compressed data storing area 26b
of the SDRAM 26 through the memory control circuit 24. In addition,
the CPU 38 applies an expansion instruction to the JPEG CODEC 32.
The JPEG CODEC 32 reads out the compressed image data from the
compressed data storing area 26b through the memory control circuit
24 so as to subject a JPEG expansion to the read compressed image
data. The resultant expanded image data is written into the image
data storing area 26a through the memory control circuit 24.
The CPU 38 has applied a process instruction to the video encoder
28 prior to detecting the image file, and the image data stored
in the image data storing area 26a is read out by the video encoder
28. The video encoder 28 converts the read image data into a composite
image signal, and supplies the converted composite image signal
to the monitor 30. As a result thereof, a reproduced image is displayed
on the monitor 30.
Furthermore, the CPU 38 reads out the header information from the
image file related to the reproduction, and determines whether or
not a specific marker is present in the read header information.
If the specific marker is detected, the mode information and the
target values are retrieved from the header information, and the
target values are set to a target value table (described later)
provided in the signal processing circuit 22 and corresponding to
the mode information.
It is noted that the image file to be reproduced is updated in
response to an operation of a cross key 42, and the reproduced image
displayed on the monitor 30 is also updated in company therewith.
The signal processing circuit 22 is structured as shown in FIG.
2. The camera data outputted from the A/D converter 20 is subjected
to the color separation by a color separating circuit 22a. That
is, each pixel data constituting the camera data has only any one
of an R element, a G element, and a B element so that two color
elements that each pixel lacks is compensated by the color separation
circuit 22a. The R element, the G element, and the B element forming
each pixel are simultaneously outputted from the color separation
circuit 22a. The R element, the G element, and the B element outputted
by each one pixel are applied to an LCH conversion circuit 22c via
a white balance adjusting circuit 22b, and converted into an L element
(luminance element), a C element (chroma element), and an H element
(hue element).
The converted L element, the C element, and the H element are applied
to an L correction circuit 22d, a C correction circuit 22e, and
an H correction circuit 22f, respectively. The L correction circuit
22d, the C correction circuit 22e, and the H correction circuit
22f subject the inputted L element, the C element, and the H element
to predetermined operations, respectively so as to evaluate a corrected
L element, a corrected C element, and a corrected H element. The
evaluated corrected L element, the corrected C element, and the
corrected H element are converted into a Y component, a U component,
and a V component by the YUV conversion circuit 22g later, and the
converted Y component, the U component, and the V component are
outputted from the signal processing circuit 22. It is noted that
the YUV conversion circuit 22g applies a so-called 4:2:2 conversion
(or 4:1:1 conversion), and the Y component, the U component, and
the V component outputted from the signal processing circuit 22
have a ratio of 4:2:2 (or 4:1:1).
The H component outputted from the LCH conversion circuit 22c is
also applied to an area determination circuit 22h. By reference
to a reference table 22m, the area determination circuit 22h determines
an area to which the H component applied from the LCH conversion
circuit 22c belongs. Then, in addition to reading out reference
values corresponding to a determination result from the reference
value table 22m, target values corresponding to the determination
result is read out from one of target value tables 22i-22k. Operations
by the L correction circuit 22d, the C correction circuit 22e, and
the H correction circuit 22f are performed on the basis of the read
reference values and the target values.
Referring to FIG. 3, six reference H component values, six reference
C component values, and six reference L component values are written
on the reference value table 22m. H, C, and L mean hue, chroma,
and luminance, respectively, and each is a parameter for a color
adjustment. An identical reference value number N (=1-6) is assigned
to the reference H component value, the reference C component value,
and the reference L component value to be associated with each other,
and the reference value is defined by three component values (the
reference H component value, the reference C component value, and
the reference L component value) having the common reference value
number. The six reference values are distributed in a YUV space
as shown in FIG. 5 and FIG. 6. It is noted that only the reference
value having the reference value number "5" is shown in
FIG. 6.
On the other hand, the target value tables 22i-22k are formed as
shown in FIG. 4. Similar to the reference value table 22m shown
in FIG. 3, six target H component values, six target C component
values, and six target L component values respectively regarding
the hue (H), the chroma (C), and the luminance (L) are set, and
the target value is defined by the target H component value, the
target C component value, and the target L component value assigned
to the identical target value number N (=1-6). When the target H
component values, the target C component values, and the target
L component values show numerical values shown in FIG. 4, the six
target values are distributed in the YUV space as shown in FIG.
5 and FIG. 6. It is noted that only the target value having the
target value number "5" is shown in FIG. 6.
The target value tables 22i-22k differ from the reference value
table 22m in that each target value can be changed. That is, the
reference H component values, the reference C component values,
and the reference L component values set to the reference value
table 22m are previously set in manufacture, thus not possible to
be freely changed by an operator. In contrary thereto, the target
H component values, the target C component values, and the target
L component values set to the target value tables 22i-22k are arbitrarily
changeable by the operator.
It is noted that both the reference value table 22h, and the target
value tables 22i-22k are stored in a non-volatile memory M. In addition,
the target value tables 22i-22k correspond to color adjustment modes
1-3, respectively.
The area determination circuit 22h executes a flowchart shown in
FIG. 7 by each one pixel in order to carry out an area determination
regarding each pixel forming the image data and a selection of the
reference values and the target values corresponding to the determination
result. Firstly, a count value N of a counter 22n is set to "1"
in a step S1, and the reference H component value corresponding
to the count value N is read out from the reference value table
22m in a step S3. In a step S5, the H component value of a current
pixel inputted from the LCH conversion circuit 22c (current pixel
H component value) is compared with the reference H component value
read out from the reference value table 22m.
If it is determined that the reference H component value is greater
than (>) the current pixel H component value in the step S5,
the count value N is compared with "1" in a step S11.
Herein, if N is equal to (=) 1, processes of steps S21-S27 are carried
out. However, if N is greater than (>) 1, processes of steps
S13-S19 are carried out. On the other hand, if the reference H component
value is less than or equal to (.ltoreq.) the current pixel H component
value, the counter 22n is incremented in a step S7, and the updated
count value N is compared with "6" in a succeeding step
S9. Furthermore, if N is less than or equal to (.ltoreq.) 6, the
process returns to the step S3. However, if N is greater than (>)
6, the processes of the steps S21-S27 are carried out.
In the step S13, the reference H component value, the reference
C component value, and the reference L component value corresponding
to the current count value N are selected as Hr1, Cr1, and Lr1 from
the reference value table 22m, and the target H component value,
the target C component value, and the target L component value corresponding
to the current count value N are selected as Ht1, Ct1, and Lt1 from
any one of the target value tables 22i-22k (table corresponding
to the current color adjustment mode) in the step S15. Furthermore,
the reference H component value, the reference C component value,
and the reference L component value corresponding to a count value
N minus (-) 1 are selected as Hr2, Cr2, and Lr2 from the reference
value table 22m in the step S17, and the target H component value,
the target C component value, and the target L component value corresponding
to the count value N minus (-) 1 are selected as Ht2, Ct2, and Lt2
from any one of the target value tables 22i-22k (table corresponding
to the current color adjustment mode) in the step S19.
On the other hand, the reference H component value, the reference
C component value, and the reference L component value corresponding
to a count value N equal to (=) 1 are selected as Hr1, Cr1, and
Lr1 from the reference table 22m in the step S21, and the target
H component value, the target C component value, and the target
L component value corresponding to a count value N equal to (=)
0 are selected as Ht1, Ct1, and Lt1 from any one of the target value
tables 22i-22k (table corresponding to the current color adjustment
mode) in the step S23. In addition, the reference H component value,
the reference C component value, and the reference L component value
corresponding to a count value N equal to (=) 6 are selected as
Hr2, Cr2, and Lr2 from the reference value table 22m in the step
S25, and the target H component value, the target C component value,
and the target L component value corresponding to the count value
N equal to (=) 6 are selected from any one of the target value tables
22i-22k as Ht2, Ct2, and Lt2 (table corresponding to the current
color adjustment mode) in the step S27.
Thus, the two reference values sandwiching the current pixel value
regarding the hue and the two target values corresponding to the
two reference values are detected.
The reference H component values Hr1 and Hr2, and the target H
component values Ht1 and Ht2 are applied to the H correction circuit
22f. In addition, the reference C component values Cr1 and Cr2,
and the target C component values Ct1 and Ct2 are applied to the
C correction circuit 22e. Furthermore, the reference L component
values Lr1 and Lr2, and the target L component values Lt1 and Lt2
are applied to the L correction circuit 22d.
The H correction circuit 22f fetches a current pixel H component
value Hin from the LCH conversion circuit 22c, and calculates a
corrected H component value Hout according to Equation 1. The calculated
corrected H component value Hout is shifted toward a degree indicated
by a dotted line shown in FIG. 8. Hout=(Ht2.beta.+Ht1.alpha.)/(.alpha.+.beta.)
[Equation 1] .alpha.=|Hr2-Hin| .beta.=|Hr1-Hin|
The H correction circuit 22f, in addition to outputting degree
data .alpha.(=|Hr2-Hin|) and .beta.(=|Hr1-Hin|) to the C correction
circuit 22e and the L correction circuit 22d, outputs degree data
.gamma.(=|Ht2-Hout|) and .delta.(=|Ht1-Hout|) to the L correction
circuit 22d.
The C correction circuit 22e subjects a current pixel C component
value Cin fetched from the LCH conversion circuit 22c to a calculation
shown in Equation 2 so as to calculate a corrected C component value
Cout shown in FIG. 9. Cout=Cin{Ct1+(Ct2-Ct1).beta./(.alpha.+.beta.)}/{Cr1+(Cr2-Cr1).bet-
a./(.alpha.+.beta.)} [Equation 2]
In addition, the C correction circuit 22e performs a calculation
of Equation 3 so as to calculate a C component value Cr3 at an intersection
coordinate of a straight line that connects CH system coordinates
(0,0), (Cin, Hin) and a straight line which connects CH system coordinates
(Cr1, Hr1), (Cr2, Hr2), and a C component value Ct3 at an intersection
coordinate of a straight line that connects CH system coordinates
(0,0), (Cout, Hout) and a straight line which connects CH system
coordinates (Ct1, Ht1), (Ct2, Ht2). The calculated C component values
Cr3 and Ct3 are outputted to the L correction circuit 22d together
with the above-described current pixel C component value Cin and
the corrected C component value Cout. Cr3=Cr1+(Cr2-Cr1).beta./(.alpha.+.beta.)
[Equation 3] Ct3=Ct1+(Ct2-Ct1).delta./(.gamma.+.delta.)
The L correction circuit 22d fetches a current pixel L component
value Lin from the LCH conversion circuit 22c so as to evaluate
a corrected L component value Lout shown in FIG. 10 according to
Equation 4. Lmax and Lmin shown in FIG. 10 are a maximum value and
a minimum value of the L (luminance) to be reproduced, respectively.
The current pixel value (inputted pixel value) exists on a surface
formed by LCH system coordinates (Lmax, 0, 0), (Lmin, 0, 0) and
(Lr3, Cr3, Hin) (a surface which cuts down the YUV space by the
hue Hin). On the other hand, a corrected pixel value exists on a
surface formed by LCH system coordinates (Lmax, 0, 0), (Lmin, 0,
0) and (Lt3, Ct3, Hout) (a surface which cuts down the YUV space
by the hue Hout). Lout=(Lin-La)(Ld-Lc)/(Lb-La)+Lc [Equation 4] La=Cin/Cr3(Lr3-Lmin)
Lb=Cin/Cr3(Lr3-Lmax)+Lmax Lc=Cout/Ct3(Lt3-Lmin) Ld=Cout/Ct3(Lt3-Lmax)+Lmax
Lr3=Lr1+(Lr2-Lr1).beta./(.alpha.+.beta.) Lt3=Lt1+(Lt2-Lt1).delta./(.gamma.+.delta.)
The corrected pixel value is defined by the corrected H component
value Hout, the corrected C component value Cout, and the corrected
L component value Lout thus evaluated. It is noted that the current
pixel value is defined by the current pixel H component value Hin,
the current pixel C component value Cin and the current pixel L
component value Lin outputted from the LCH conversion circuit 22c.
The CPU 38 carries out a flowchart shown in FIG. 11 when the photographing
mode is selected, and carries out a flowchart shown in FIG. 12 when
the reproduction mode is selected. It is noted that program corresponding
to these flowcharts is stored in a ROM 45.
When the photographing mode is selected, a through image display
process is carried out in a step S31. More specifically, a process
instruction is applied to the TG 16, the signal processing circuit
22, and the video encoder 28. This allows a real time moving image
of the object to be displayed on the monitor 30. It is determined
whether or not the shutter button 40 is operated in a step S33,
and if YES is determined, an image compression process is carried
out in a step S35. More specifically, a compression instruction
is applied to the JPEG CODEC 32. This allows one frame of the compressed
image data to be stored into the compressed data storing area 26b.
In a step S37, six reference values are read out from the reference
value table 22m, and six target values are read out from any one
of the target value tables 22i-22k (table corresponding to the current
color adjustment mode) so as to create header information including
the read reference values and the target values, and the mode information
showing the current color adjustment mode. In a step S39, the compressed
image data is read out from the compressed data storing area 26b
through the memory control circuit 24, the image file including
the compressed image data and the header information created in
the step S37 is created, and the created image file is recorded
into the memory card 36 through the I/F circuit 34. The process
returns to the step S31 after completing the process.
When the reproduction mode is selected, a process instruction is
applied to the video encoder 28 in order to start-up a display system
in a step S41, and a latest image file is specified from a plurality
of image files recorded in the memory card 36 in a step S43. The
specified image file is reproduced in a step S45. More specifically,
the compressed image data stored in the image file is read out through
the I/F circuit 34, the read compressed image data is written into
the compressed data storing area 26b through the memory control
circuit 24, and an expansion instruction is applied to the JPEG
CODEC 32. The JPEG CODEC 32 reads out the compressed image data
through the memory control circuit 24, applies a JPEG expansion
to the compressed image data, and the expanded image data is written
into the image data storing area 26a through the memory control
circuit 24.
In a step S47, the header information is read out from the image
file related to the reproduction, and it is determined whether or
not the specific marker is present in the header information. If
NO is herein determined, the process directly proceeds to a step
S53. However, if YES is determined, the process proceeds to the
step S53 via processes of steps S49 and S51. The target value table
corresponding to the mode information included in the header information
is specified in the step S49, and in the step S51, the target value
included in the header information is set to the target value table
specified in the step S49. In a case that the mode information included
in the header information shows "color adjustment mode 1",
for example, the target values included in the header information
is set to the target value table 22i.
It is determined whether or not the cross key 42 is operated in
a step S53, and if the cross key 42 is operated, the process updates
the image file regarding the reproduction in a step S55 before returning
to the step S45.
Referring to FIG. 13, the memory card 36 taken out from the digital
camera 10 is attached to the personal computer (PC) 50. Color adjustment
program having the same color adjustment function as the digital
camera 10 is stored in a ROM 54, and the CPU 52 applies the color
adjustment toward each image file recorded in the memory card 36
according to a flowchart shown in FIG. 14 when the color adjustment
program is started.
Firstly, a desired image file recorded in the memory card 36 is
read out through the I/F circuit 34 in a step S61, and the read
image file is written into a RAM 56. The read image file is reproduced
in a step S63. More specifically, the JPEG expansion is applied
to the compressed image data included in the image file, and the
expanded image data is applied to the monitor 62 via the I/F circuit
60. The reproduced image is displayed on the monitor 62. The reference
values and the target values are detected from the header information
of the image file regarding the reproduction in a step S65, and
a color adjustment menu on the basis of the detected reference values
and the target values is GUI-displayed on the monitor 62 in a succeeding
step S67.
It is determined whether or not the color adjustment is operated
in a step S69, and it is determined whether or not a color adjustment
ending operation is present in a step S71. When the color adjustment
operation is performed, the target values are changed in a step
S73, and the color adjustment is carried out on the basis of the
changed target values in a step S75. More specifically, the area
determination is carried out according to the same manner as in
the flowchart shown in FIG. 7 with respect to each pixel forming
the reproduced image so as to change the hue, the chroma, and the
luminance of the pixel to be noticed on the basis of the two reference
values and the two target values specified thereby. As a result,
a color reproduction characteristic of the reproduced image is changed.
When the color adjustment ending operation is performed, the process
proceeds from the step S71 to a step S77 so as to write the target
values changed in the step S73 into the image file regarding the
reproduction. More specifically, the target values included in the
header information of the image file regarding the reproduction
is updated by the target values changed in the step S73. A marker
is written into the header information of the same image file in
a step S79 before ending the process. It is noted that when the
color adjustment ending operation is performed without changing
the target value, the process is ended without circulating the steps
of S77 and S79.
As understood from the above descriptions, the image data of the
object photographed in the photographing mode is subjected to the
color adjustment on the basis of the reference values set to the
reference value table 22m and the target values set to any one of
the target value tables 22i-22k (table corresponding to the current
color adjustment mode). The through image on the basis of the image
data to which the color adjustment is applied is displayed on the
monitor 30. When the shutter button 40 is operated, the compressed
image data is generated by the JPEG CODEC 32, the header information
including the aforementioned reference values and the target values,
and the mode information showing the current color adjustment mode
is generated by the CPU 38, and the image file including the header
information and the compressed image data is recorded into the memory
card 36 by the CPU 32.
In the reproduction mode, it is determined by the CPU 38 whether
or not the target values included in the image file is changed.
The specific marker is included in the header information of the
image file having the changed target values so that whether or not
the target values are changed is determined on the basis of the
specific marker. If the specific marker is detected, the CPU 38
specifies the target value table corresponding to the mode information
included in the same header information, and overwrites the target
values of the target value table by the changed target values.
Thus, the reference values and the target values corresponding
to the current color adjustment mode, together with the compressed
image data, are stored in the image file. Accordingly, if the image
file is transferred to the PC 50, it is possible to adjust the color
reproduction characteristic of the image on the basis of the compressed
image data, and change the target values in accordance with the
adjustment. If the target values are thus changed, the target values
of the corresponding target value table is overwritten by the changed
color adjustment values, and the changed target values are reflected
on the color adjustment of the image data. That is, it becomes possible
to exactly adjust the color reproduction characteristic of the photographed
image data as a result of a mechanism recording the target values
into the image file and a mechanism overwriting the target values
set to the target value table by the target values within the image
file.
It is noted that in this embodiment, a detachable memory card is
used as a recording medium. However, the recording medium may be
an incorporated type. In this case, the image file may be fetched
into the PC by connecting the PC with the digital camera by a cable.
Furthermore, in this embodiment, the parameter adjustable by the
PC is only a parameter regarding the color adjustment. However,
an image quality other than the color may be adjusted by the PC
if a gamma corrected value or a setting value of a dynamic range
is to be included in the image file.
Although the present invention has been described and illustrated
in detail, it is clearly understood that the same is by way of illustration
and example only and is not to be taken by way of limitation, the
spirit and scope of the present invention being limited only by
the terms of the appended claims.
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