FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“IMAGING DEVICE, COLOUR-CORRECTION
METHOD AND COLOUR-CORRECTION PROGRAM”
SONY CORPORATION, of 1-7-1, Konan, Minato-ku, Tokyo
108-0075, Japan
The following specification particularly describes the invention and the manner in
which it is to be performed.

DESCRIPTION
Title of Invention
IMAGE PICKUP APPARATUS, COLOR CORRECTION METHOD, AND COLOR
CORRECTION PROGRAM
Technical Field
[0001] The present disclosure relates to an image pickup apparatus obtaining an image
pickup signal with use of a dimming device, and to a color correction method and a
color correction program that are applied to such an image pickup signal.
Background Art
[0002] In an image pickup apparatus such as a digital camera (a digital still camera), a
diaphragm (an iris) that performs mechanical dimming operation (light quantity
adjustment) is typically provided as a dimming device adjusting light quantity of image
pickup light. Moreover, recently, as an alternative to such a mechanical diaphragm, an
electrical dimming device (a liquid crystal dimming device) using a guest-host (GH)
type liquid crystal that contains dichroic pigment has been proposed (for example, refer
to PTL 1).
Citation list
Patent Literature
[0003] PTL 1: Japanese Unexamined Patent Application Publication No.
2001-142050
Summary of Invention
[0004] Incidentally, in the image pickup apparatus incorporating the various kinds of
dimming device as described above, an image pickup signal is obtained by the image
pickup device through such a dimming device. As for the image pickup signal
obtained in such a way, it is assumed a case where color correction is necessary
SP340782
2
depending on situations, and thus a method of achieving appropriate color correction is
desired.
[0005] Therefore, it is desirable to provide an image pickup apparatus, a color
correction method, and a color correction program that are capable of performing
appropriate color correction on an image pickup signal that is obtained with use of a
dimming device.
[0006] An image pickup apparatus according to an embodiment of the present
disclosure includes: a dimming device configured to adjust light quantity of incident
image pickup light; an image pickup device configured to obtain an image pickup signal
based on image pickup light emitted from the dimming device; and a color correction
processing section configured to perform color correction on the image pickup signal
that is obtained by the image pickup device, based on information relating to light
quantity of the image pickup light emitted from the dimming device. The color
correction processing section performs the color correction to allow a color balance
value of the image pickup signal to be substantially constant independent of the light
quantity of the image pickup light emitted from the dimming device.
[0007] A color correction method according to an embodiment of the present
disclosure includes steps of: obtaining an image pickup signal by an image pickup
device based on image pickup light emitted from a dimming device, the dimming
device being configured to adjust light quantity of incident image pickup light; and
performing color correction on the image pickup signal obtained by the image pickup
device, based on information relating to light quantity of the image pickup light emitted
from the dimming device. In the step of performing the color correction, the color
correction is performed to allow a color balance value of the image pickup signal to be
substantially constant independent of the light quantity of the image pickup light
emitted from the dimming device.
[0008] A color correction program according to an embodiment of the present
SP340782
3
disclosure causes a computer to execute steps of: obtaining an image pickup signal that
is obtained by an image pickup device, based on image pickup light emitted from a
dimming device, the dimming device being configured to adjust light quantity of
incident image pickup light; and performing color correction on the image pickup signal,
based on information relating to light quantity of the image pickup light emitted from
the dimming device. In the step of performing the color correction, the color
correction is performed to allow a color balance value of the image pickup signal to be
substantially constant independent of the light quantity of the image pickup light
emitted from the dimming device.
[0009] In the image pickup apparatus, the color correction method, and the color
correction program according to the respective embodiments of the present disclosure,
based on the information relating to the light quantity of the image pickup light emitted
from the dimming device, the color correction to the image pickup signal is performed
to allow the color balance value of the image pickup signal obtained by the image
pickup device to be substantially constant independent of the light quantity of the image
pickup light emitted from the dimming device. In other words, the color correction in
consideration of the information relating to the light quantity of the image pickup light
emitted from the dimming device is achieved.
[0010] According to the image pickup apparatus, the color correction method, and the
color correction program according to the respective embodiments of the present
disclosure, the color correction to the image pickup signal obtained by the image pickup
device is performed based on the information relating to the light quantity of the image
pickup light emitted from the dimming device. Therefore, the color correction in
consideration of such information relating to the light quantity is achieved. Therefore,
it is possible to perform appropriate color correction on the image pickup signal
obtained using the dimming device.
SP340782
4
Brief Description of Drawings
[0011] [FIG. 1] FIG. 1 is a block diagram illustrating a schematic configuration
example of an image pickup apparatus according to a first embodiment of the
disclosure.
[FIG. 2] FIG. 2 is a sectional diagram illustrating a configuration example of a liquid
crystal dimming device as an example of a dimming device illustrated in FIG. 1.
[FIG. 3] FIG. 3 is a block diagram illustrating a detailed configuration example of a
color correction processing section illustrated in FIG. 1.
[FIG. 4] FIG. 4 is a schematic diagram illustrating an example of relationship between
a drive voltage and a light transmittance of incident light in the liquid crystal dimming
device illustrated in FIG. 2.
[FIG. 5] FIG. 5 is a characteristic diagram illustrating an example of relationship
between a wavelength of the incident light and transmittance in the liquid crystal
dimming device.
[FIG. 6] FIG. 6 is a schematic diagram illustrating an example of a correction table
illustrated in FIG. 4.
[FIG. 7] FIG. 7 is a flowchart illustrating an example of color correction processing
according to the first embodiment.
[FIG. 8] FIG. 8 is a schematic diagram illustrating a calculation example of a color
correction value in the color correction processing illustrated in FIG. 7.
[FIG. 9] FIG. 9 is a block diagram illustrating a schematic configuration example of
an image pickup apparatus according to a second embodiment.
[FIG. 10] FIG. 10 is a block diagram illustrating a detailed configuration example of a
color correction processing section illustrated in FIG. 9.
[FIG. 11] FIG. 11 is a schematic diagram illustrating an example of a color correction
table illustrated in FIG. 10.
[FIG. 12] FIG. 12 is a diagram illustrating a detailed structure example of the
SP340782
5
correction table illustrated in FIG. 11.
[FIG. 13] FIG. 13 is a flowchart illustrating an example of color correction processing
according to the second embodiment.
[FIG. 14] FIG. 14 is a schematic diagram illustrating a calculation example of a color
correction value in the color correction processing illustrated in FIG. 13.
[FIG. 15] FIG. 15 is a block diagram illustrating a configuration example of a color
correction processing section according to modifications 1 and 2.
Description of Embodiments
[0012] Some embodiments of the disclosure will be described in detail below with
reference to the accompanying drawings. Note that description will be given in the
following order.
1. First Embodiment (an example of performing color correction with use of drive
voltage information and temperature information)
2. Second Embodiment (an example of performing color correction with use of light
transmittance information and temperature information)
3. Modifications
Modification 1 (an example of performing color correction with use of drive
voltage information (an example not using temperature information))
Modification 2 (an example of performing color correction with use of light
transmittance information (an example not using temperature information))
4. Other Modifications
[0013]
[Configuration of Image Pickup Apparatus 1]
FIG. 1 illustrates a schematic configuration of an image pickup apparatus (an
image pickup apparatus 1) according to a first embodiment of the disclosure by way of a
block diagram. The image pickup apparatus 1 may be a digital camera (a digital still
SP340782
6
camera) that converts an optical image from an object into an electrical signal by an
image pickup device (an image pickup device 23 described later). Note that the image
pickup signal obtained in such a way is capable of being recorded in a semiconductor
recording medium (not illustrated) and being displayed on a display unit (not illustrated)
such as a liquid crystal display.
[0014] The image pickup apparatus 1 includes a lens 21, a dimming device 22, the
image pickup device 23, a temperature sensor 3, a signal processing section 4, and a
drive section 5. Note that a color correction method according to an embodiment of
the disclosure is embodied in the image pickup apparatus 1 of the present embodiment
(specifically, in a color correction processing section 43 described later), and thus is
described together. The same applies to other embodiment, modifications, and the like
described later.
[0015] The lens 21 is configured of one lens in this case; however may be configured
of a lens group including a plurality of lenses.
[0016] The dimming device 22 is a device configured to adjust light quantity of the
image pickup light (image pickup light Lin) entering from the lens 21 side, and is
disposed on an optical path (on an optical path of the image pickup light) between the
lens 21 and the image pickup device 23 in this case. As the dimming device 22, for
example, a device (a liquid crystal dimming device) that performs electrical light
quantity adjustment (dimming) with use of a liquid crystal may be used. Note that the
detailed configuration of such a liquid crystal dimming device will be described later
(FIG. 2).
[0017] The image pickup device 23 is a device configured to detect the image pickup
light (image pickup light Lout emitted from the dimming device 22) that enters the
image pickup device 23 from the lens 21 through the dimming device 22, to obtain an
image pickup signal Sin. The image pickup device 23 may be configured using, for
example, an imaging sensor (a solid-state image pickup device) such as CCD
SP340782
7
(Charge-Coupled Device) and CMOS (Complementary Metal-Oxide Semiconductor).
[0018] The temperature sensor 3 is a device that is disposed in the vicinity (peripheral
region) of the dimming device 22, and is configured to detect temperature in the vicinity
of the dimming device 22. The temperature sensor 3 may be configured using, for
example, a thermistor. Note that temperature information Item that is detected in this
way and indicates the temperature in the vicinity of the dimming device 22 is output to
a light quantity control section 44.
[0019] (Signal Processing Section 4)
The signal processing section 4 is configured to perform predetermined signal
processing on the image pickup signal Sin obtained by the image pickup device 23, and
to perform predetermined feedback control (light quantity control described later) on the
dimming device 22. The signal processing section 4 includes an S/HAGC circuit 41,
an A/D conversion section 42, a color correction processing section 43, and the light
quantity control section (an light transmittance control section) 44.
[0020] The S/HAGC circuit 41 is a circuit configured to perform S/H (sample and
hold) processing on the image pickup signal Sin output from the image pickup device
23, and to perform predetermined signal amplification processing with use of AGC
(Automatic Gain Control) function.
[0021] The A/D conversion section 42 is configured to perform A/D conversion
(analog to digital conversion) processing on an image pickup signal output from the
S/HAGC circuit 41 to generate an image pickup signal S1 as a digital signal.
[0022] The color correction processing section 43 is configured to perform color
correction processing as image quality improvement processing on the image pickup
signal S1 (the digital signal) output from the A/D conversion section 42 to output an
image pickup signal Sout after such color correction processing. Although the detail
will be described later, the color correction processing section 43 uses the temperature
information Item and drive voltage information Iv described later that are supplied from
SP340782
8
the light quantity control section 44, to perform the color correction processing. In
other words, the color correction processing section 43 uses such drive voltage
information Iv to perform the color correction processing, thereby performing the color
correction processing with indirectly use of light transmittance information Itra (light
quantity information) described later. Note that the image pickup signal Sout
generated by such color correction processing is output to the outside (a semiconductor
recording medium, etc. not illustrated) of the signal processing section 4. In addition,
the detailed configuration of the color correction processing section 43 will be described
later (FIG. 3).
[0023] The light quantity control section 44 supplies a control signal of the dimming
device 22 to the drive section 5, to control dimming operation (light quantity adjustment
operation) of the dimming device 22. In this case, as the control signal of the dimming
device 22, the light transmittance information Itra (light quantity information indicating
light quantity (the transmitted light quantity and brightness) of the image pickup light
Lout (emission light) emitted from the dimming device 22) indicating the light
transmittance of the image pickup light Lin (incident light) of the dimming device 22.
[0024] Specifically, the light quantity control section 44 detects a signal vale of the
image pickup signal S1 output from the A/D conversion section 42, and then sets the
light transmittance information Itra (the light quantity information) based on the signal
value (a detection value). In other words, the light quantity control section 44
determines the light quantity (the transmitted light quantity) of the image pickup light
Lout emitted from the dimming device 22, based on the signal value of the image
pickup signal S1, to output the information Itra relating to the light quantity. In
addition, the light quantity control section 44 also has a function of performing
predetermined temperature correction (temperature correction of the transmitted light
quantity) using the temperature information Item output from the temperature sensor 3
with use of data (a table) indicating "correspondence relationship between the
SP340782
9
temperature and the transmitted light quantity" that is previously stored in a
not-illustrated memory section (a memory).
[0025] The drive section 5 is configured to perform drive operation on the dimming
device 22 based on the light transmittance information Itra (the light quantity
information) supplied from the light quantity control section 44. Specifically, the
drive section 5 determines drive voltage V to the dimming device 22 based on such light
transmittance information Itra, and supplies the drive voltage V to the dimming device
22 (between transparent electrodes 221a and 221b described later), thereby performing
the drive operation. In this case, the information indicating the drive voltage V
determined at that time corresponds to the above-described drive voltage information Iv.
Note that the detail of a method of determining the drive voltage V will be described
later (FIG. 4).
[0026] [Detailed Configuration Example of Dimming Device 22]
FIG. 2 schematically illustrates a cross-sectional surface configuration example
of the dimming device 22 (the liquid crystal dimming device). The dimming device 22
has a stacked structure in which a transparent substrate 221a, a transparent electrode
222a, an alignment film 223a, a liquid crystal layer 220, an alignment film 223b, a
transparent electrode 222b, and a transparent electrode 221b are stacked in this order
from an incident side of the image pickup light Lin toward an emission side of the
image pickup light Lout. Moreover, the dimming device 22 also includes a sealing
agent 224, a spacer 225, and a sealing section 226.
[0027] The liquid crystal layer 220 is a layer containing liquid crystal molecules, and
in this case, containing predetermined pigment molecules (dichroic dye molecules) in
addition to the liquid crystal molecules (the liquid crystal molecules and the pigment
molecules are collectively denoted by molecules M for simplification of illustration in
FIG. 2). In other words, the dimming device 22 is configured using a guest-host (GH)
type liquid crystal containing a pigment (a dichroic pigment).
SP340782
10
[0028] Such a liquid crystal of GH type (a GH type liquid crystal) is roughly
classified into a negative type and a positive type depending on a long-axis direction of
the liquid crystal molecules at the time of voltage application. In the positive GH type
liquid crystal, the long-axis direction of the liquid crystal molecules is perpendicular to
the optical axis at the time of no-voltage application (in an OFF state), and the long-axis
direction of the liquid crystal molecules is parallel to the optical axis at the time of
voltage application (in an ON state). On the other hand, in the negative GH type liquid
crystal, the long axis direction of the liquid crystal molecules is parallel to the optical
axis at the time of no-voltage application, and the long-axis direction of the liquid
crystal molecules is perpendicular to the optical axis at the time of voltage application.
In this case, the pigment molecules are aligned in the direction same as that of the liquid
crystal molecules, and thus when the positive liquid crystal is used as a host, the light
transmittance is relatively low (the light emission side is relatively dark) at the time of
no-voltage application, and the light transmittance is relatively high (the light emission
side is relatively bright) at the time of voltage application. On the other hand, when
the negative liquid crystal is used as a host, inversely, the light transmittance is
relatively high (the light emission side is relatively bright) at the time of no-voltage
application, and the light transmittance is relatively low (the light emission side is
relatively dark) at the time of voltage application. Note that, in the present
embodiment, the liquid crystal layer 260 may be configured of either one of the positive
liquid crystal or the negative liquid crystal; however, the case where the liquid crystal
layer 260 is configured of the negative liquid crystal is described as a representative.
[0029] Each of the transparent electrodes 222a and 222b is an electrode configured to
apply a voltage (the drive voltage V) to the liquid crystal layer 220, and may be formed
of, for example, Indium Tin Oxide (ITO). Note that wirings (not illustrated) to
electrically connected to the transparent electrodes 222a and 222b may be disposed as
appropriate.
SP340782
11
[0030] Each of the alignment films 223a and 223b is a film to align the liquid crystal
molecules in the liquid crystal layer 220 in a desired direction (an alignment direction).
Each of the alignment films 223a and 223b may be formed of, for example a polymer
material such as polyimide, and is previously subjected to rubbing treatment in a
predetermined direction to allow the alignment direction of the liquid crystal molecules
to be set.
[0031] The transparent substrate 221a is a one-side substrate that supports the
transparent electrode 222a and the alignment film 223a and seals the liquid crystal layer
220. The transparent substrate 221b is the other-side substrate that supports the
transparent electrode 222b and the alignment film 223b and seals the liquid crystal layer
220. Each of the transparent substrates 221a and 221b may be formed of, for example,
a glass substrate.
[0032] The sealing agent 224 is a member to seal molecules M (the liquid crystal
molecules and the pigment molecules) in the liquid crystal layer 220 from side surface
sides, and may be formed of, for example, an adhesive agent such as an epoxy adhesive
agent and an acrylic adhesive agent. The spacer 225 is a member to maintain a
constant cell gap (a constant thickness) of the liquid crystal layer 220, and may be
formed of, for example a predetermined resin material or a glass material. The sealing
section 226 is a sealing port used when the molecules M are sealed into the liquid
crystal layer 220, and is a part to subsequently seal the molecules M in the liquid crystal
layer 220 from outside.
[0033] [Detailed Configuration Example of Color Correction Processing Section 43]
FIG. 3 illustrates a detailed configuration example of the color correction
processing section 43 by way of a block diagram. The color correction processing
section 43 includes a color correction value calculation section 431, a correction table
432 (a second correction table), and a multiplication section 433.
[0034] The color correction value calculation section 431 uses the image pickup
SP340782
12
signal S1, the drive voltage information Iv and the temperature information Item that are
supplied from the light quantity control section 44, and the correction table 432, to
obtain color correction values Gain (gain values) for the color correction processing.
[0035] The correction table 432 is a table that is configured by making the drive
voltage information Iv correspond to the color correction values Gain previously, and in
particular in this case, the temperature information is also made correspond thereto.
Such a correction table 432 may be held in advance in a not-illustrated memory section
(the memory), for example. Note that the detailed structure of the correction table 432
will be described later (FIG. 6).
[0036] The multiplication section 433 multiplies the image pickup signal S1 by the
color correction values Gain output from the color correction value calculation section
431, to generate an image pickup signal Sout (= S1Gain) after the color correction
processing.
[0037] [Function and Effects of Image Pickup Apparatus 1]
(1. Image Pickup Operation)
As illustrated in FIG. 1, in the image pickup apparatus 1, the image pickup
light Lin emitted from the lens 21 enters the dimming device 22, and the light quantity
(the transmitted light quantity) of the image pickup light Lin is adjusted to be output as
the image pickup light Lout. The image pickup light Lout enters the image pickup
device 23, and then is detected, and thus the image pickup signal Sin is obtained.
[0038] At this time, in the dimming device 22 (the liquid crystal dimming device)
illustrated in FIG. 2, for example, the image pickup light Lin (the incident light) passes
through the liquid crystal layer 220 and the like, and is emitted as the image pickup light
Lout (the emission light). At this time, when a predetermined voltage (the drive
voltage V) is applied between the transparent electrodes 222a and 222b, the alignment
direction (the long axis direction) of the molecules M (the liquid crystal molecules and
the pigment molecules) in the liquid crystal layer 220 changes, and the light quantity
SP340782
13
(the transmitted light quantity) of the image pickup light Lout that passes through the
liquid crystal layer 220 is accordingly changed. In other words, the light transmittance
of the incident image pickup light Lin is changed. Therefore, adjustment of the drive
voltage V at this time enables electrical (not mechanical) adjustment of the light
quantity (the light transmittance of the image pickup light Lin) of the image pickup light
Lout that passes through the entire dimming device 22 (enables arbitrary dimming
operation). In this way, the light quantity adjustment (dimming) to the image pickup
light is performed in the dimming device 22.
[0039] Here, FIG. 4 schematically illustrates an example of relationship between the
drive voltage V to be applied and the transmittance (a light transmittance T) of the
image pickup light Lin in the dimming device 22 (the liquid crystal dimming device).
In this example, the negative GH type liquid crystal is used in the liquid crystal layer
220, and illustration is made with the light quantity (the transmitted light quantity) of
the image pickup light Lout in the no-voltage application state (in the OFF state) as a
reference (100%). It is found from FIG. 4 that, as the drive voltage V is increased, the
shielded light quantity in the liquid crystal layer 220 is drastically increased (the light
transmittance T is drastically decreased), and is converged to a substantially constant
value (in the ON state). Each of the value, the gradient, and the dimming range at the
time of such a change of the light transmittance T of the dimming device 22 varies
according to the material and the concentration of the liquid crystal layer 220 (the liquid
crystal and the pigment), the cell gap (the thickness) of the liquid crystal layer 220,
kinds (materials) of the alignment films 223a and 223b, etc. Note that when the
positive GH type liquid crystal is used in the liquid crystal layer 220, in contrast to the
characteristics in FIG. 4, the transmittance is low in the no-voltage application state, and
the light transmittance T is increased as the drive voltage V is increased.
[0040] Subsequently, the signal processing section 4 performs predetermined signal
processing on the image pickup signal Sin obtained as described above, and performs
SP340782
14
predetermined feedback control (light quantity control) on the dimming device 22.
More specifically, first, the S/HAGC circuit 41 performs S/H processing on the image
pickup signal Sin and also performs predetermined signal amplification processing
using the AGC function on the image pickup signal Sin. Subsequently, the A/D
conversion section 42 performs the A/D conversion processing to generate the image
pickup signal S1 of the digital signal. Then, the color correction processing section 43
performs color correction processing described later on the image pickup signal S1 to
generate the image pickup signal Sout after the color correction processing.
[0041] On the other hand, the light quantity control section 44 in the signal processing
section 4 uses a signal value (a detection value) of the image pickup signal S1 and the
temperature information Item (the temperature information in the vicinity of the
dimming device 22) output from the temperature sensor 3, to set and to the light
transmittance information Itra (the light quantity information) as the control signal of
the dimming device 22 and output the light transmittance information Itra. Then, the
drive section 5 performs the drive operation on the dimming device 22 based on the
light transmittance information Itra supplied from the light quantity control section 44.
More specifically, the drive section 5 determines the drive voltage V of the dimming
device 22 based on such light transmittance information Itra, and supplies the drive
voltage V to the dimming device 22 (between the transparent electrodes 221a and 221b)
to perform the drive operation. At this time, the drive section 5 uses a characteristic
line (for example, see FIG. 4 described above) indicating relationship between the light
transmittance T and the drive voltage V in the dimming device 22, to determine the
drive voltage V from the light transmittance information Itra. In the example
illustrated in FIG. 4, the drive voltage V = V1 is obtained from the light transmittance
T1 indicated by the light transmittance information Itra.
[0042] (2. Color Correction Processing)
Incidentally, in the image pickup signal obtained through the dimming device,
SP340782
15
typically, color balance (color shade, white balance) of the image pickup signal is
shifted depending on situations, which causes degradation in quality of a picked-up
image in some cases.
[0043] Specifically, for example, as illustrated in FIG. 5, first, the light transmittance
of the image pickup light slightly varies according to the wavelength region of the
image pickup light both in the ON state (shielded state) and the OFF state (non-shielded
state) of the dimming device. In addition, in the ON state in particular, the light
transmittance for each wavelength range does not uniformly vary according to the
variation of the temperature (the environment temperature in the vicinity of the
dimming device). Specifically, in this example, the light transmittance is decreased as
the temperature is increased from low to high in each of blue (B) wavelength region and
green (G) wavelength region, whereas the light transmittance is increased as the
temperature is increased from low to high in red (R) wavelength region. In this way,
the color shade of the image pickup light that has passed through the dimming device is
changed according to the transmitted light quantity (brightness) and the temperature of
the image pickup light at that time, and thus the color balance (white balance) of the
image pickup signal is changed. Note that such a shift of the color balance in the
image pickup signal remarkably occurs in the case of the liquid crystal dimming device.
[0044] Therefore, in the present embodiment, the color correction processing section
43 in the signal processing section 4 performs color correction processing described
below on the image pickup signal (in this case, the image pickup signal S1 after the
subsequent signal processing) obtained through the dimming device 22, to reduce the
shift of the color balance described above.
[0045] In other words, as illustrated in FIG. 1 and FIG. 3, the color correction
processing section 43 indirectly uses information (the light transmittance information
Itra) relating to the light quantity (the transmitted light quantity) of the image pickup
light Lout emitted from the dimming device 22, to perform the color correction
SP340782
16
processing on the image pickup signal S1. Specifically, the color correction
processing section 43 uses the drive voltage information Iv (the information indicating
the drive voltage V of the dimming device 22) and the temperature information Item
(the information indicating the temperature in the vicinity of the dimming device 22)
that are supplied from the light quantity control section 44, to perform such color
correction processing. More specifically, the color correction processing section 43
uses the correction table 432 that is configured by making the drive voltage information
Iv correspond to the color correction values Gain previously, to perform the color
correction processing.
[0046] For example, as illustrated in (A) of FIG. 6, as the correction table 432, a table
that is configured by making the values of the drive voltage information Iv correspond
to the color correction values Gain (for example, a red color correction value R_Gain
and blue color correction value B_Gain) by a predetermined characteristic line may be
used. Alternatively, for example, as illustrated in (B) of FIG. 6, a table that is
configured by making the values of the drive voltage information Iv correspond to the
color correction values Gain for each value (low temperature, ambient temperature, high
temperature, and the like) of the temperature information Item by a predetermined
characteristic line may be used. Note that, in this case, caused by the fact that the
relationship between the drive voltage V and the light transmittance T in the dimming
device 22 (the liquid crystal dimming device) is typically defined by a characteristic line
formed of a cubic expression, the characteristic line defining the correspondence
therebetween in the correction table 432 is also a characteristic line formed of a cubic
expression. In other words, a correction expression defining the correspondence in the
correction table 432 is a cubic expression in this case.
[0047] Further, the color correction processing section 43 uses the color correction
values Gain obtained by such a correction table 432 to perform the color correction
processing so that the color balance value of the image pickup signal Sout is
SP340782
17
substantially constant (desirably constant) independent of both the light quantity of the
image pickup light Lout emitted from the dimming device 22 and the temperature in the
vicinity of the dimming device 22. Specifically, in the present embodiment, the color
correction processing section 43 may perform the color correction processing in a
manner as illustrated in FIG. 7, for example.
[0048] More specifically, as described above, the color correction processing section
43 acquires the drive voltage information Iv and the temperature information Item from
the light quantity control section 44 (steps S11 and S12 in FIG. 7). Then, the color
correction processing section 43 uses the drive voltage information Iv and the
temperature information Item that are acquired in such a way, to obtain the color
correction values Gain from the above-described correction table 432 (step S13).
[0049] Specifically, for example, as illustrated in (A) of FIG. 8, first, the color
correction values Gain (for example, the red color correction value R_Gain = Rx and
the blue color correction value B_Gain = Bx) are obtained from the drive voltage Vx
that is indicated by the drive voltage information Iv. The cubic expression (an
approximate expression) in the correction table 432 at this time may be expressed by the
following expressions (1) and (2), for example. Note that coefficients aR, bR, cR, dR, aB,
bB, cB, and dB in the expressions are held in the correction table 432. In such a way,
the color correction values Gain by the drive voltage V are first obtained.
Rx = aRVx3+bRVx2+cRVx+dR (1)
Bx = aBVx3+bBVx2+cBVx+dB (2)
[0050] Next, for example, as illustrated in (B) of FIG. 8, the color correction
processing section 43 obtains the color correction values Gain in consideration of the
temperature (the temperature in the vicinity of the dimming device 22) indicated by the
temperature information Item. This is because the color correction values Gain each
vary according to the temperature even if the drive voltage V is the same, as illustrated
in (B) of FIG. 6 described above. However, for example, as illustrated in (B) of FIG. 8,
SP340782
18
since there is linear relationship between the temperature and the color correction values
Gain, for example, the color correction values Gain, for example, only at two
temperatures, at high temperature (70C in this case) and at low temperature (-10C in
this case) may be held in the correction table 432. In this case, the color correction
values R_Gain and B_Gain at 70C are denoted by R(T70) and B(T70), respectively, and
the color correction values R_Gain and B_Gain at -10C are denoted by R(T-10) and
B(T-10), respectively. In addition, the color correction values Gain at the temperature
therebetween (R_Gain = R(Tx) and B_Gain = B(Tx)) are obtained from the linear
interpolation expressed by the following expressions (3) to (5). In this way, the color
correction values Gain in consideration of the temperature in the vicinity of the
dimming device 22 are obtained
R(Tx) = R(T-10)+{R(T70)-R(T-10)} (3)
B(TX) = B(T-10)+{B(T70)-B(T-10)} (4)
 = [Tx/{70-(-10)}] (5)
[0051] As described above, the color correction processing section 43 finally
multiplies the image pickup signal S1 by the color correction values Gain thus obtained
to generate the image pickup signal Sout (= S1Gain) after the color correction
processing. In this way, the color correction processing by the color correction
processing section 43 is ended.
[0052] In the present embodiment, the color correction in consideration of the
information (the light transmittance information Itra) relating to the light quantity of the
image pickup light Lout emitted from the dimming device 22 is achieved by such color
correction processing. In addition, in this case in particular, the color correction is
performed in consideration of the temperature information (the temperature information
Item) in the vicinity of the dimming device 22, in addition to such information (the light
transmittance information Itra) relating to the light quantity.
[0053] As described above, in the present embodiment, the color correction
SP340782
19
processing to the image pickup signal S1 obtained through the dimming device 22 is
performed based on (in this case, with indirectly use of) the information (the light
transmittance information Itra) relating to the light quantity of the image pickup light
Lout emitted from the dimming device 22. Therefore, it is possible to achieve the
color correction in consideration of such information relating to the light quantity.
Accordingly, it is possible to perform appropriate color correction on the image pickup
signal obtained with use of the dimming device 22.
[0054] Moreover, in the present embodiment, in particular, the color correction
processing is performed also with use of the temperature information Item indicating
the temperature in the vicinity of the dimming device 22, in addition to the information
(the light transmittance information Itra) relating to the light quantity. Therefore, it is
possible to achieve color reproduction including the temperature characteristics.
[0055]
[Configuration of Image Pickup Apparatus 1A]
FIG. 9 illustrates a schematic configuration of an image pickup apparatus (an
image pickup apparatus 1A) according to a second embodiment of the present
disclosure by way of a block diagram. The image pickup apparatus 1A has a signal
processing section 4A in place of the signal processing section 4 in the image pickup
apparatus 1 of the first embodiment, and other configurations thereof are similar to
those of the image pickup apparatus 1. Incidentally, in the following description, like
numerals are used to designate substantially like components in the first embodiment,
and description thereof is appropriately omitted.
[0056] The signal processing section 4A has a color correction processing section 43A
in place of the color correction processing section 43 in the signal processing section 4
according to the first embodiment, and other configurations thereof are similar to those
of the signal processing section 4. Unlike the color correction processing section 43,
the color correction processing section 43A uses the temperature information Item and
SP340782
20
the light transmittance information Itra (the light quantity information) that are supplied
from the light quantity control section 44, to perform the color correction processing.
In other words, the color correction processing section 43 indirectly uses the
information (the light transmittance information Itra) relating to the light quantity of the
image pickup light Lout to perform the color correction processing, whereas the color
correction processing section 43A directly uses the information relating to the light
quantity of the image pickup light Lout to perform the color correction processing.
[0057] For example, as illustrated in FIG. 10, the color correction processing section
43A may include a color correction value calculation section 431A, a correction table
432A, and the multiplication section 433. In other words, the color correction
processing section 43A has the color correction value calculation section 431A and the
correction table 432A (a first correction table) in place of the color correction value
calculation section 431 and the correction table 432 in the color correction processing
section 43.
[0058] The color correction value calculation section 431A uses the image pickup
signal S1, the light transmittance information Itra and the temperature information Item
that are supplied from the light quantity control section 44, and the correction table 432,
to obtain the color correction values Gain in the color correction processing.
[0059] The correction table 432A is a table that is configured by making the light
transmittance information Itra correspond to the color correction values Gain previously,
and in this case in particular, the temperature information Item is also made
corresponded thereto. Such a correction table 432A may be also previously held in,
for example, a memory section (memory) that is not illustrated.
[0060] As such a correction table 432A, for example, as illustrated in (A) of FIG. 11,
a table that is configured by making the values of the light transmittance information
Itra correspond to the color correction values Gain (for example, a red color correction
value R_Gain and a blue color correction value B_Gain) by a predetermined
SP340782
21
characteristic line may be used. Alternatively, for example, as illustrated in (B) of FIG.
11, a table that is configured by making the values of the light transmittance information
Itra correspond to the color correction values Gain for each value (low temperature,
ambient temperature, high temperature, and the like) of the temperature information
Item by a predetermined characteristic line, may be used.
[0061] In this case, in the color correction processing of the present embodiment,
caused by the fact that the color correction processing is performed with directly use of
the light transmittance information Itra as described above, a characteristic line defining
the correspondence in the correction table 432A is a characteristic line formed of a
linear expression. In other words, the correction expression defining the
correspondence in the correction table 432A is a linear expression. Therefore, the
values of the light transmittance information Itra and the color correction values Gain
have linear relationship. In this way, the correction table 432 according to the first
embodiment has a correction expression of a complicated cubic expression, whereas the
correction table 432A according to the present embodiment has a correction expression
of a linear expression. Accordingly, simple and precise color correction processing as
compared with the first embodiment is achieved.
[0062] Moreover, in the correction table 432A, a part of the color correction values
Gain located on the above-described correction expression (the linear expression) is
allowed to be interpolated and generated by linear interpolation (linear function
interpolation). Specifically, the color correction values (illustrated by a straight line on
the correction expression) other than the color correction values Gain illustrated by dots
on the correction expression in (A) and (B) of FIG. 11 may be interpolated and
generated by such linear interpolation. In such a case, the structure of the correction
table 432A becomes simpler (the data capacity is allowed to be further reduced).
[0063] Note that FIG. 12 specifically illustrates an example of such a correction table
432A. In this example, the values of the light transmittance information Itra (defined
SP340782
22
by a light transmittance ratio with darkest state as a reference) are made correspond to
the color correction values Gain (the red color correction value R_Gain and the blue
color correction value B_Gain) for each value (-10C to 70C) of the temperature
information Item.
[0064] Further, the color correction processing section 43A of the present
embodiment also uses the color correction values Gain obtained from such a correction
table 432A to perform the color correction processing similarly to that in the first
embodiment. Specifically, the color correction processing section 43A performs the
color correction processing so that the color valance value of the image pickup signal
Sout is substantially constant (desirably constant) independent of both the light quantity
of the image pickup light Lout emitted from the dimming device 22 and the temperature
in the vicinity of the dimming device 22. More specifically, in the present
embodiment, the color correction processing section 43A may perform the color
correction processing in a manner as illustrated in FIG. 13, for example.
[0065] To be more specific, as described above, the color correction processing
section 43A acquires the light transmittance information Itra and the temperature
information Item from the light quantity control section 44 (steps S21 and S22 in FIG.
13). Subsequently, the color correction processing section 43A uses the light
transmittance information Itra and the temperature information Item thus acquired to
obtain the color correction values Gain from the above-described correction table 432A
(step S23).
[0066] Specifically, for example, as illustrated in FIG. 14, the color correction values
Gain (for example, R_Gain =Rx and B_Gain = Bx) may be first obtained from a light
transmittance Ex that is indicated by the light transmittance information Itra. At this
time, unlike the first embodiment, the color correction processing section 43A holds
only coordinates of two points P0 and P1 illustrated in FIG. 14 in the correction table
432A, and uses linear interpolation represented by the following expressions (6) to (8)
SP340782
23
to obtain coordinates of a point Px that defines the color correction values Gain. In
this way, the color correction values Gain by the light transmittance are first obtained.
Rx = R0+a(R1-R0) (6)
Bx = B0+a(B1-B0) (7)
a = (Ex/1.33) (8)
[0067] Next, the color correction processing section 43A obtains the color correction
values Gain in consideration of the temperature (the temperature in the vicinity of the
dimming device 22) indicated by the temperature information Item in a manner similar
to the step S13 described in the first embodiment.
[0068] Finally, the color correction processing section 43A, as described above,
multiplies the image pickup signal S1 by the color correction values Gain thus obtained
to generate the image pickup signal Sout (= S1Gain) after the color correction
processing. In the above-described way, the color correction processing by the color
correction processing section 43A is ended.
[0069] [Function and Effects of Image Pickup Apparatus 1A]
Also in the image pickup apparatus 1A of the present embodiment, the similar
effects may be basically obtained by the similar function to that of the image pickup
apparatus 1 of the first embodiment. Specifically, the color correction in consideration
of the information relating to the light quantity is allowed to be achieved, and
appropriate color correction is allowed to be performed on the image pickup signal
obtained using the dimming device 22. Moreover, since the color correction
processing is performed with use of the temperature information Item indicating the
temperature in the vicinity of the dimming device 22 in addition to the information (the
light transmittance information Itra) relating to the light quantity, color reproduction
including temperature characteristics is allowed to be achieved.
[0070] Moreover, in the color correction processing section 43A of the present
embodiment, in particular, the color correction processing is performed witu directly
SP340782
24
use of the information relating to the light quantity of the image pickup light Lout.
Therefore, the correction expression in the correction table 432A is a linear expression,
and thus simple and precise color correction processing is allowed to be achieved as
compared with the first embodiment.
[0071]
Subsequently, modifications (modifications 1 and 2) of the above-described
first and second embodiments will be described. Note that like numerals are used to
designate substantially like components in the first and second embodiments, and
description thereof is appropriately omitted.
[0072] [Modifications 1 and 2]
(A) of FIG. 15 illustrates a block configuration of a color correction processing
section (a color correction processing section 43B) according to a modification 1. In
addition, (B) of FIG. 15 illustrates a block configuration of a color correction processing
section (a color correction processing section 43C) according to a modification 2.
[0073] The color correction processing section 43B of the modification 1 has a color
correction value calculation section 431B in place of the color correction value
calculation section 431 in the color correction processing section 43 of the first
embodiment, and other configurations thereof are similar to those of the color correction
processing section 43. In the color correction processing section 43B, unlike the color
correction processing section 43, the color correction value calculation section 431B
uses the drive voltage information Iv supplied from the light quantity control section 44,
to perform the color correction processing without using the temperature information
Item supplied from the light quantity control section 44. Accordingly, for example,
the correction table illustrated in (A) of FIG. 6 described above may be used as the
correction table 432 in the present modification.
[0074] The color correction processing section 43C of the modification 2 has a color
correction value calculation section 431C in place of the color correction value
SP340782
25
calculation section 431A in the color correction processing section 43A of the second
embodiment, and other configurations thereof are similar to those of the color correction
processing section 43A. In the color correction processing section 43C, unlike the
color correction processing section 43A, the color correction value calculation section
431C uses the light transmittance information Itra (the light quantity information)
supplied from the light quantity control section 44, to perform the color correction
processing section without using the temperature information Item supplied from the
light quantity control section 44. Accordingly, for example, the correction table
illustrated in (A) of FIG. 11 described above may be used as the correction table 432A
in the present modification.
[0075] As with the modifications 1 and 2, the color correction processing may be
performed directly or indirectly using the information (the light transmittance
information Itra) relating to the light quantity of the image pickup light Lout without
using the temperature information Item supplied from the light quantity control section
44. In this case, the color correction processing sections 43B and 43C each perform
the color correction processing so that the color balance value of the image pickup
signal Sout is substantially constant (desirably constant) independent of the light
quantity of the image pickup light Lout emitted from the dimming device 22.
[0076]
Hereinbefore, although the technology of the present disclosure has been
described with referring to some embodiments and the modifications, the technology is
not limited to the embodiments and the like, and various modifications may be made.
[0077] For example, in the above-described embodiments and the like, the liquid
crystal dimming device using GH type liquid crystal has been described as an example,
type of the liquid crystal is not limited thereto, and a liquid crystal dimming device
using a liquid crystal other than the GH type liquid crystal may be used, and further, a
dimming device other than the liquid crystal dimming device may be used.
SP340782
26
[0078] Specifically, as the dimming device other than the liquid crystal dimming
device, dimming devices of the following system may be used. More specifically, for
example, a dimming device using a gel material that is used in thermochromism
(practical examples: a mug, a polymer sheet, and the like) and thermotropic, a dimming
device using a material in photochromic (practical examples: sunglass changed by an
ultraviolet ray, and the like), a dimming device using hydrogen gas and the like in
gaschromic (practical examples: window glass, and the like), a dimming device using
WO3 (tungsten oxide), Nb2O5 (niobium oxide), NiO (nickel oxide), Cr2O3 (chromium
oxide), and the like in electrochromic (practical examples: window glass, and the like)
may be used.
[0079] Furthermore, although each component (the block configuration of the signal
processing section) of the image pickup apparatus has been specifically described in the
above-described embodiment, all of the components are not necessarily provided, and
other components may be further provided. For example, although the case where one
lens (lens group) is provided in the image pickup apparatus (on the optical path of the
image pickup light) has been described as an example in the above-described
embodiments and the like, the number of lenses is not limited thereto. In other words,
for example, a plurality of lenses (lens groups) may be provided on the optical path of
the image pickup light, and alternatively, such a lens (lens group) may not be provided
in the image pickup apparatus.
[0080] Moreover, the signal processing (the color correction processing and the like)
described in the above-described embodiments and the like may be executed by
hardware (a circuit) or by software (program). In the case where the signal processing
is executed by software, the software is configured of a program group causing a
computer (a microcomputer or the like in the image pickup apparatus) to execute each
signal processing function (the color correction processing function and the like). For
example, each program may be incorporated in dedicated hardware in advance or may
SP340782
27
be installed from any network or a recording medium to a multipurpose personal
computer and used.
[0081] Note that the present technology may be configured as follows.
(1) An image pickup apparatus including:
a dimming device configured to adjust light quantity of incident image pickup
light;
an image pickup device configured to obtain an image pickup signal based on
image pickup light emitted from the dimming device; and
a color correction processing section configured to perform color correction on
the image pickup signal that is obtained by the image pickup device, based on
information relating to light quantity of the image pickup light emitted from the
dimming device, wherein
the color correction processing section performs the color correction to allow a
color balance value of the image pickup signal to be substantially constant independent
of the light quantity of the image pickup light emitted from the dimming device.
(2) The image pickup apparatus according to (1), wherein the color correction
processing section directly uses the information relating to the light quantity to perform
the color correction.
(3) The image pickup apparatus according to (2), wherein the color correction
processing section uses a first correction table to perform the color correction, the first
correction table being configured by making the information relating to the light
quantity correspond to color correction values in advance.
(4) The image pickup apparatus according to (3), wherein a correction
expression defining the correspondence in the first correction table is a linear
expression.
(5) The image pickup apparatus according to (4), wherein a part of the color
correction values located on the linear expression is interpolated and generated by linear
SP340782
28
interpolation.
(6) The image pickup apparatus according to any one of (2) to (5), further
including:
a light quantity control section configured to determine the light quantity of the
image pickup light emitted from the dimming device, based on a signal value of the
image pickup signal, and output the information relating to the light quantity; and
a drive section configured to determine a drive voltage to the dimming device,
based on the information relating to the light quantity output from the light quantity
control section, and supply the drive voltage to the dimming device, wherein
the color correction processing section acquires the information relating to the
light quantity from the light quantity control section.
(7) The image pickup apparatus according to (1), wherein the color correction
processing section indirectly uses the information relating to the light quantity to
perform the color correction.
(8) The image pickup apparatus according to (7), wherein the color correction
processing section uses drive voltage information indicating a drive voltage to the
dimming device, to perform the color correction, the drive voltage information being
determined based on the information relating to the light quantity.
(9) The image pickup apparatus according to (8), wherein the color correction
processing section uses a second correction table to perform the color correction, the
second correction table being configured by making the drive voltage information
correspond to color correction values in advance.
(10) The image pickup apparatus according to (8) or (9), further including:
a light quantity control section configured to determine the light quantity of the
image pickup light emitted from the dimming device, based on a signal value of the
image pickup signal, and output the information relating to the light quantity; and
a drive section configured to determine the drive voltage, based on the
SP340782
29
information relating to the light quantity, and supply the drive voltage to the dimming
device, the information relating to the light quantity being output from the light quantity
control section, wherein
the color correction processing section acquires the drive voltage information
from the drive section through the light quantity control section.
(11) The image pickup apparatus according to any one of (1) to (10), wherein
the color correction processing section uses, in addition to the information relating to
the light quantity, temperature information indicating temperature in the vicinity of the
dimming device to perform the color correction.
(12) The image pickup apparatus according to (11), wherein the color
correction processing section performs the color correction to allow the color balance
value of the image pickup signal to be substantially constant independent of both the
light quantity of the image pickup light emitted from the dimming device and the
temperature in the vicinity of the dimming device.
(13) The image pickup apparatus according to any one of (1) to (12), wherein
the information relating to the light quantity is information indicating a light
transmittance of the dimming device.
(14) The image pickup apparatus according to any one of (1) to (13), wherein
the dimming device is a liquid crystal dimming device.
(15) The image pickup apparatus according to any one of (1) to (14), further
including
one or a plurality of lenses provided on an optical path of the image pickup
light.
(16) A color correction method including:
obtaining an image pickup signal by an image pickup device based on image
pickup light emitted from a dimming device, the dimming device being configured to
adjust light quantity of incident image pickup light; and
SP340782
30
performing color correction on the image pickup signal obtained by the image
pickup device, based on information relating to light quantity of the image pickup light
emitted from the dimming device, wherein
in performing the color correction, the color correction is performed to allow a
color balance value of the image pickup signal to be substantially constant independent
of the light quantity of the image pickup light emitted from the dimming device.
(17) A color correction program causing a computer to execute:
obtaining an image pickup signal that is obtained by an image pickup device,
based on image pickup light emitted from a dimming device, the dimming device being
configured to adjust light quantity of incident image pickup light; and
performing color correction on the image pickup signal, based on information
relating to light quantity of the image pickup light emitted from the dimming device,
wherein
in performing the color correction, the color correction is performed to allow a
color balance value of the image pickup signal to be substantially constant independent
of the light quantity of the image pickup light emitted from the dimming device.
[0082] This application is based upon and claims the benefit of priority of the
Japanese Patent Application No. 2011-264959 filed in the Japan Patent Office on
December 2, 2011, the entire contents of this application are incorporated herein by
reference.
[0083] It should be understood by those skilled in the art that various modifications,
combinations, sub-combinations, and alterations may occur depending on design
requirements and other factors insofar as they are within the scope of the appended
claims or the equivalents thereof.
SP340782
31
CLAIMS
1. An image pickup apparatus comprising:
a dimming device configured to adjust light quantity of incident image pickup
light;
an image pickup device configured to obtain an image pickup signal based on
image pickup light emitted from the dimming device; and
a color correction processing section configured to perform color correction on
the image pickup signal that is obtained by the image pickup device, based on
information relating to light quantity of the image pickup light emitted from the
dimming device, wherein
the color correction processing section performs the color correction to allow a
color balance value of the image pickup signal to be substantially constant independent
of the light quantity of the image pickup light emitted from the dimming device.
2. The image pickup apparatus according to claim 1, wherein the color
correction processing section directly uses the information relating to the light quantity
to perform the color correction.
3. The image pickup apparatus according to claim 2, wherein the color
correction processing section uses a first correction table to perform the color correction,
the first correction table being configured by making the information relating to the
light quantity correspond to color correction values in advance.
4. The image pickup apparatus according to claim 3, wherein a correction
expression defining the correspondence in the first correction table is a linear
expression.
SP340782
32
5. The image pickup apparatus according to claim 4, wherein a part of the color
correction values located on the linear expression is interpolated and generated by linear
interpolation.
6. The image pickup apparatus according to claim 2, further comprising:
a light quantity control section configured to determine the light quantity of the
image pickup light emitted from the dimming device, based on a signal value of the
image pickup signal, and output the information relating to the light quantity; and
a drive section configured to determine a drive voltage to the dimming device,
based on the information relating to the light quantity output from the light quantity
control section, and supply the drive voltage to the dimming device, wherein
the color correction processing section acquires the information relating to the
light quantity from the light quantity control section.
7. The image pickup apparatus according to claim 1, wherein the color
correction processing section indirectly uses the information relating to the light
quantity to perform the color correction.
8. The image pickup apparatus according to claim 7, wherein the color
correction processing section uses drive voltage information indicating a drive voltage
to the dimming device, to perform the color correction, the drive voltage information
being determined based on the information relating to the light quantity.
9. The image pickup apparatus according to claim 8, wherein the color
correction processing section uses a second correction table to perform the color
correction, the second correction table being configured by making the drive voltage
SP340782
33
information correspond to color correction values in advance.
10. The image pickup apparatus according to claim 8, further comprising:
a light quantity control section configured to determine the light quantity of the
image pickup light emitted from the dimming device, based on a signal value of the
image pickup signal, and output the information relating to the light quantity; and
a drive section configured to determine the drive voltage, based on the
information relating to the light quantity, and supply the drive voltage to the dimming
device, the information relating to the light quantity being output from the light quantity
control section, wherein
the color correction processing section acquires the drive voltage information
from the drive section through the light quantity control section.
11. The image pickup apparatus according to claim 1, wherein the color
correction processing section uses, in addition to the information relating to the light
quantity, temperature information indicating temperature in the vicinity of the dimming
device to perform the color correction.
12. The image pickup apparatus according to claim 11, wherein the color
correction processing section performs the color correction to allow the color balance
value of the image pickup signal to be substantially constant independent of both the
light quantity of the image pickup light emitted from the dimming device and the
temperature in the vicinity of the dimming device.
13. The image pickup apparatus according to claim 1, wherein the information
relating to the light quantity is information indicating a light transmittance of the
dimming device.
SP340782
34
14. The image pickup apparatus according to claim 1, wherein the dimming
device is a liquid crystal dimming device.
15. The image pickup apparatus according to claim 1, further comprising
one or a plurality of lenses provided on an optical path of the image pickup
light.
16. A color correction method comprising:
obtaining an image pickup signal by an image pickup device based on image
pickup light emitted from a dimming device, the dimming device being configured to
adjust light quantity of incident image pickup light; and
performing color correction on the image pickup signal obtained by the image
pickup device, based on information relating to light quantity of the image pickup light
emitted from the dimming device, wherein
in performing the color correction, the color correction is performed to allow a
color balance value of the image pickup signal to be substantially constant independent
of the light quantity of the image pickup light emitted from the dimming device.
17. A color correction program causing a computer to execute:
obtaining an image pickup signal that is obtained by an image pickup device,
based on image pickup light emitted from a dimming device, the dimming device being
configured to adjust light quantity of incident image pickup light; and
performing color correction on the image pickup signal, based on information
relating to light quantity of the image pickup light emitted from the dimming device,
wherein
in performing the color correction, the color correction is performed to allow a
color balance value of the image pickup signal to be substantially constant independent
of the light quantity of the image pickup light emitted from the dimming device.