Output level
US008743289B2
(12) United States Patent
(10) Patent N0.:
(45) Date of Patent:
Mukai
(54)
IMAGE DISPLAY APPARATUS AND IMAGE
US 8,743,289 B2
Jun. 3, 2014
FOREIGN PATENT DOCUMENTS
DISPLAY METHOD
EP
JP
JP
JP
JP
JP
(75) Inventor: Kazuo Mukai, Kyoto (JP)
(73) Assignee: Panasonic Corporation, Osaka (JP)
(*)
Notice:
Subject to any disclaimer, the term of this
patent is extended or adjusted under 35
1752958 A2 *
05-080101
10-049068
2007-047440
2007-226052
2009-171192
2/2007
4/1993
2/1998
2/2007
9/2007
7/2009
* cited by examiner
U.S.C. 154(b) by 195 days.
Primary Examiner * Michael Lee
(21) Appl. N0.: 12/910,339
(22)
Filed:
(74) Attorney, Agent, 0rFirm * Hamre, Schumann, Mueller
& Larson, RC.
Oct. 22, 2010
(65)
Prior Publication Data
US 2011/0096238 A1
(30)
(57)
Apr. 28, 2011
ABSTRACT
An image display apparatus of the present invention includes:
a picture display unit that forms and displays an optical image
Foreign Application Priority Data
based on a video signal; a gamma adjustment image display
Oct. 26, 2009
(JP) ............................... .. 2009-245139
unit that displays a gamma adjustment image containing
input/output characteristics of a signal level of the video
(51)
Int. Cl.
(52)
H04N 5/202
H04N 9/69
US. Cl.
signal in the displayed optical image; an adjustment operation
(2006.01)
(2006.01)
unit that changes the displayed input/ output characteristics on
the image; and an input/output characteristics setting unit that
sets input/ output characteristics of the signal level of the
video signal in accordance With the input/ output characteris
tics changed on the image. The adjustment operation unit
includes a point selecting part that selects an adjustment point
desired to be changed in the input/output characteristics dis
played in the image and a level changing part that is capable
USPC .......................... .. 348/674; 348/675; 345/594
(58)
Field of Classi?cation Search
USPC ................ .. 348/674, 675, 254, 256; 345/594;
358/519
See application ?le for complete search history.
(56)
of changing both of an input level and an output level of the
References Cited
selected adjustment point. Because both of an input signal
level and an optical output level can be adjusted, a user can
U.S. PATENT DOCUMENTS
7,551,179 B2*
2006/0164442 A1*
2007/0046596 A1
6/2009
7/2006
make gamma adjustment easily, freely, and in detail.
Sakakibara et a1. ........ .. 345/594
Furuhata et a1. ............ .. 345/690
7 Claims, 8 Drawing Sheets
3/2007 Sakakibara et al.
Y adjustment
lOeuvtplut
Input level
Input 1%
In:
US. Patent
Jun. 3, 2014
Sheet 1 0f8
US 8,743,289 B2
N4
ml
lIenvpeult
{55-1 NI
FIG.1
US. Patent
Jun. 3, 2014
Sheet 3 0f8
8»
I00
FIG.3
US 8,743,289 B2
US. Patent
Jun. 3, 2014
.
Sheet 4 0f8
5a
US 8,743,289 B2
.
Y gamma adjustment screen f_1
5d
B gamma adjustment screen ,_J
Y adjustment
B adjustment
T:
E
5
'
‘“
5
““
t3
.E_______
i%
<3
0
a;
i3
<5
Input level
Point N
Input l%
,
Input level
Output 0
Point N
5b
Input l%
.
R gamma adjustment screen f~J
Output 0
50
G gamma adjustment screen [-1
R adjustment
G adjustment
3
B
5
__
5
'
.
__
45
é:
a
0
a
C)
Input level
Point N
Input l%
Input level
Output 0
Point N
FIG.4
Input I%
Output 0
US. Patent
Jun. 3, 2014
Sheet 5 0f8
Update an adjustment value
(input level or output Y/R/G/B adjustment value)
US 8,743,289 B2
N310
by a remote control operation
l
RGB -> YCbCr conversion or YCbCr —> RGB conversion NSZO
l
Wr ite the adjustment value in an adjustment value N330
storage memory 19
Generate gamma data of address 8 bit and data 8
N340
bit from 9 points' adjustment values
Fi lter ing of the gamma data
~350
Convert the data generated by fi ltering to a
format with an address
width and a data width of LUT 15
“360
l
Send data to the LUT15
FlG.5
~S7O
US 8,743,289 B2
1
2
IMAGE DISPLAY APPARATUS AND IMAGE
DISPLAY METHOD
characteristics changed on the image. The adjustment opera
tion unit includes a point selecting part that selects an adjust
ment point desired to be changed in the input/output charac
teristics displayed in the image and a level changing part that
is capable of changing both of an input level and an output
level of the selected adjustment point.
An image display method of the present invention
includes: forming and displaying an optical image based on a
video signal; displaying a gamma adjustment image contain
ing input/ output characteristics of a signal level of the video
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image display apparatus
and an image display method in which a user is capable of
performing gamma adjustment easily and in detail with
respect to images such as picture contents.
2. Description of Related Art
In recent years, there is an increasing demand for image
signal in the displayed optical image; changing the displayed
input/output characteristics on the image; and setting the
input/output characteristics of the signal level of the video
signal in accordance with the input/ output characteristics
changed on the image, wherein, when the input/output char
acteristics are changed on the image, an adjustment point
desired to be changed in the input/output characteristics dis
played in the image is selected, and both of an input level and
an output level of the selected adjustment point are changed.
display apparatuses capable of displaying a vibrant picture on
a large screen, along with the spread of digital versatile disks
(DVDs), blu-ray disks (BDs), and the like. Examples of such
image display apparatuses include projectors that are proj ec
tion type image display apparatuses, which can be combined
with a screen to display a large screen picture.
Of the projectors, a projector, particularly, for home use
that is commercially available is being requested to have
higher image quality and more functions every year, along
20
with an increase in size of a screen. Therefore, the projector
tends to have various functions of adjusting images so that a
user can adjust images such as picture contents in accordance
with the user’ s preference. The functions of adjusting images
include gamma adjustment, i.e., a function of adjusting the
the input level and the output level of a video signal, and
hence, can perform adjustment easily, freely, and in detail.
25
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating an example of a
display screen on which an image for performing gamma
level of an optical output with respect to the level of a video
signal input to an image display apparatus. A device has also
adjustment is displayed by an image display apparatus of
been proposed, which has a function for allowing a user to
adjust a level of an optical output with respect to the level of
an input signal of a particular picture while watching a screen
of an on-screen menu, for performing gamma adjustment.
According to the above-mentioned con?guration, when a
user performs gamma adjustment, the user can change both
30
Embodiment 1 according to the present invention.
FIG. 2 is a block diagram illustrating a circuit con?guration
of the image display apparatus of Embodiment 1 according to
An example of the function of adjusting images mounted
the present invention.
FIG. 3 is a diagram illustrating an operation of gamma
on a projector is described in US 2007/0046596 A1, and JP
described in this document is one allowing a user to adjust an
adjustment in the image display apparatus of Embodiment 1
according to the present invention.
optical output level with respect to each input level at posi
tions of a plurality of particular input signal levels prepared
adjustment image in the image display apparatus of Embodi
2009-171192 A. The function of gamma adjustment
previously on a producer side.
However, in the function of gamma adjustment mounted on
a projector described in the above-mentioned document, the
user can adjust an optical output level only at positions of
35
FIG. 4 is a diagram illustrating a transition of a gamma
40
display apparatus of Embodiment 1 according to the present
input signal levels prepared previously on a producer side.
invention.
FIG. 6 is a block diagram illustrating another example of
Therefore, there is a limit for a user to adjust an optical output
level with the input signal level preferred by the user, which
ment 1 according to the present invention.
FIG. 5 is a ?ow chart of processing conducted by a main
microcomputer at a time of gamma adjustment in the image
45
makes it dif?cult for the user to perform adjustment freely and
in detail. Further, this function is limited to the adjustment of
the circuit con?guration of the image display apparatus of
Embodiment 1 according to the present invention.
FIG. 7 is a block diagram illustrating a circuit con?guration
of an image display apparatus of Embodiment 2 according to
the present invention.
Y (luminance), and therefore, it is impossible to perform
adjustment with each color of R, G, and B.
50
SUMMARY OF THE INVENTION
FIG. 8 is a perspective view illustrating a use form of a
projector that is an image display apparatus of Embodiment l
or 2 according to the present invention.
Therefore, with the foregoing in mind, the present inven
tion solves the above-mentioned conventional problems, and
its object is to provide an image display apparatus and an
image display method enabling a user to perform gamma
DETAILED DESCRIPTION OF THE INVENTION
55
The image display apparatus of the present invention can
adjustment easily, freely, and in detail.
An image display apparatus of the present invention
includes: a picture display unit that forms and displays an
optical image based on a video signal; a gamma adjustment
assume the following aspects based on the above-mentioned
con?guration.
More speci?cally, the image display apparatus of the
60
image display unit that displays a gamma adjustment image
containing input/ output characteristics of a signal level of the
video signal in the displayed optical image; an adjustment
operation unit that changes the displayed input/output char
acteristics on the image; and an input/output characteristics
setting unit that sets input/output characteristics of the signal
level of the video signal in accordance with the input/ output
present invention can be con?gured so as to include an adjust
ment value storage memory capable of storing and reading
data of the changed input/ output level.
Further, the image display apparatus of the present inven
tion can be con?gured in such a manner that data of the stored
65
input/output level can be read and rewritten via an input/
output terminal enabling control from outside. According to
this con?guration, regarding the set value of the adjusted
US 8,743,289 B2
3
4
result, the set value data of gamma adjustment can be
ured. The operations of the LUT 15 and the on-screen gen
eration processing circuit 16 are controlled by a main con
exchanged easily among users, for example, storage data can
be copied to a main body of another device, using an external
control tool.
Further, the adjustment operation unit can be con?gured so
troller (microcomputer) 17.
To the main microcomputer 17, a remote control photode
tector part 18 that receives light representing a remote control
code generated by a remote control operation, an adjustment
value storage memory 19 for storing an adjustment value of
gamma adjustment, and operation buttons 20 mounted on a
main body are connected. Gamma data is created based on the
as to perform an operation of changing an input level and an
output level with respect to Y (luminance).
Further, the adjustment operation unit can be con?gured so
as to perform an operation of changing an input level and an
adjustment value stored in the adjustment value storage
output level with respect to any monochrome of R, G, and B.
memory 19 and supplied to the LUT 15. The LUT 15 consti
Further, the image display apparatus of the present inven
tutes an input/output characteristics setting unit for setting
input/output characteristics of a video signal in accordance
tion can be provided with a freeze processing circuit enabling
the adjustment of the input/output characteristics while freez
with gamma data.
ing a moving image signal.
FIG. 3 is an explanatory diagram illustrating an operation
of gamma adjustment in the image display apparatus 1 with
the above-mentioned con?guration. In the explanatory dia
Hereinafter, the present invention will be described in
detail by way of illustrative embodiments with reference to
the drawings.
Embodiment 1
FIG. 1 is a perspective view illustrating an example of a
display screen 2 on which an image for performing gamma
gram, the display screen 2 and the remote controller 3 of FIG.
1 are displayed as seen when the gamma adjustment image 5
20
adjustment is displayed by an image display apparatus 1 of
value is changed, and a character string 10 displays input/
output values of adjustment points. Further, FIG. 4 is an
explanatory diagram illustrating a transition of the gamma
Embodiment 1 according to the present invention. FIG. 1
further illustrates a remote controller 3, which is an example
of an operation unit for operating gamma adjustment.
An ordinary picture display image 4 based on a video
25
30
control photodetector part 18 is input to the main microcom
puter 17 as a result of the operation by the remote controller
3, an on-screen menu is generated in a video signal by the
on-screen generation processing circuit 16. The on-screen
represents an input level and a vertical axis represents an
output level. On a reference line 6 showing initial input/
output characteristics, adjustment points 7 corresponding to
respective values of input levels are displayed. Of the adjust
ment points 7, an adjustment point 711 desired to be changed
adjustment image 5 in the image display apparatus 1.
The operation of the image display apparatus con?gured as
described above will be described with reference to FIGS. 2 to
4.
When remote control code information from the remote
signal is displayed on the display screen 2, and a gamma
adjustment image 5 displaying a diagram showing input/
output characteristics is displayed in the picture display
image 4. In the input/ output characteristics diagram dis
played in the gamma adjustment image 5, a horizontal axis
is in operation. That is, the adjustment point 711 in FIG. 3
indicates a position to which a currently selected gamma
menu displays the gamma adjustment image 5 in the picture
35
display image 4.
The gamma adjustment image 5 shows input/ output char
is displayed in a form so as to be discriminated from other
acteristics of a video signal, con?gured so as to indicate an
adjustment points 7.
input level of a signal on the horizontal axis and an output
level of a signal on the vertical axis, as described above. A
The remote controller 3 is provided with a selection button
8 composing a part of the operation buttons as means for
40
lower left point of the image where the input level and the
45
output level cross each other is an origin, and the input level
shows a higher level in a rightward direction and the output
level shows a higher level in an upward direction in the screen.
The diagonal reference line 6 shows reference values at which
gamma adjustment is not performed on the screen.
selecting a point desired to be changed. The remote controller
3 also is provided with change buttons 9 composed of buttons
operating the movement in vertical and horizontal directions
as means for changing an input level and an output level of the
selected point, which constitute an adjustment operation unit.
The currently selected adjustment point 711 is displayed so
FIG. 2 is a block diagram illustrating a circuit con?guration
of the image display apparatus 1. Elements related to a
as to be discriminated from other adjustment points 7. When
gamma adjustment image display unit for displaying the
the adjustment point 711 is to be adjusted, the input level is
gamma adjustment image 5 of FIG. 1 mainly are illustrated,
and elements related to a picture display unit for displaying
the picture display image 4 are illustrated in a simpli?ed
changed with a right-and-left arrow button of the remote
50
controller 3, and the output level is changed with an up-and
down arrow button. FIG. 3 shows a state in which the adjust
manner.
ment point 711 is changed in the leftward direction from the
The image display apparatus 1 is con?gured so as to pro
cess a video signal input from a video signal input terminal
11, form an optical image on a liquid crystal panel 13 by a
reference value, and further changed in the upward direction.
The changed value is calculated by the main microcomputer
17 simultaneously, and data of the LUT 15 is rewritten by the
55
liquid crystal panel drive circuit 12, and project the optical
result of the calculation, so as to be re?ected immediately on
image onto a screen 14. Thus, the picture display unit for
displaying the picture display image 4 of FIG. 1 as a picture
based on a video signal is con?gured. It should be noted that
a signal processing circuit for this purpose is not shown since
a well-known con?guration may be adopted.
The input video signal is supplied to an on-screen genera
tion processing circuit 16 via a look-up table (LUT) 15. The
on-screen generation processing circuit 16 outputs, based on
the output signal from the LUT 15, a signal for displaying an
on-screen menu to the liquid crystal panel drive circuit 12.
the picture of the picture display image 4.
Regarding the processing by the main microcomputer 17,
if linear interpolation is performed between the point of the
Thus, the gamma adjustment image display unit is con?g
60
changed value and an adjacent point, unsmoothness is caused
in a picture. Therefore, it is necessary to calculate a smooth
curve, using ?ltering with a low-pass ?lter, spline interpola
tion, etc., to create LUT data.
Further, the value obtained by changing the input level and
65
the output level is displayed as a numerical value in the
character string 10 of input/output display of adjustment
points in the gamma adjustment image 5. In this case, for
US 8,743,289 B2
6
5
example, the input level is changed every 1% and displayed
by “%”. The output level is changed every 0.4% (1/255) and
In FIG. 5, when an adjustment value (an input level or an
displayed by an integer value such as +1, +2, . . . , when
output Y/R/G/ B adjustment value) of the adjustment point 711
selected by a remote control operation is updated (Step S10),
increased and —1 , —2, . . . , when decreased, with the reference
the RGBQYCbCr conversion or the YCbCrQRGB conver
value being 0. Another display method may be used.
Further, the gamma adjustment image 5 can be adjusted not
only withY (luminance) but also with R, G, and B individu
sion of the updated adjustment point 711 is performed (Step
S20). After that, the adjustment values of the nine adjustment
of the remote controller 3, as illustrated in FIG. 4, the gamma
adjustment image can be switched as follows: Y gamma
points 7 are written in the adjustment value storage memory
19 (Step S30). Next, gamma data of address 8 bit and data 8
bit is generated from the adjustment values of the nine adjust
ment points 7 (Step S40), and the gamma data is subjected to
adjustment image 5a—>R gamma adjustment image SbQG
gamma adjustment image 50—>B gamma adjustment image
is converted to a format with an address width and a date
5d to select color, and thus, adjustment can be performed.
width of the LUT 15 (Step S60), and the data is sent to the
Alternatively, a color may be adjusted by an on-screen menu.
LUT 15 (Step S70).
The circuit con?guration of the image display apparatus 1
ally. More speci?cally, by pressing another operation button
Further, when a color is changed, an adjusted position
calculated for each color of an adjustment point is displayed
for each adjustment. For example, when Y (luminance) is
adjusted, YCbCr—>RGB conversion described later is per
formed, and when individual adjustment of R/G/ B is per
formed, RGBQYCbCr conversion is performed, and the cal
culated value is re?ected on the gamma adjustment image 5.
?ltering (Step S50). Then, the data generated by the ?ltering
illustrated in FIG. 2 can be changed to the con?guration as
illustrated in the block diagram of FIG. 6. The con?guration
of the image display apparatus 111 of FIG. 6 is obtained by
adding a freeze processing circuit 21 to the con?guration of
20
FIG. 2. According to this con?guration, an image can be
adjusted while a moving image signal is being frozen (made
Expressions used for conversions are as follows.
still).
The following expressions are used for the RGBQYCbCr
conversion.
Further, adjustment also can be performed with the opera
tion buttons 20 of the main body instead of performing an
operation with the remote controller 3.
Embodiment 2
FIG. 7 is a block diagram illustrating a circuit con?guration
of an image display apparatus 1b of Embodiment 2 according
25
to the present invention. The image display apparatus 1b of
30
The following expressions are used for the YCbCr—>RGB
conversion.
FIG. 7 has a con?guration obtained by further adding an
input/output terminal for external control 22 such as
RS-232C to the con?guration of FIG. 2. The same constituent
elements as those of FIG. 2 are denoted with the same refer
35
connecting the image display apparatus 1b to a personal com
puter. This enables data stored in the adjustment value storage
memory 19 storing the results obtained by the above-men
When Y is adjusted as described above, the calculation
results thereof are re?ected on a graph on the gamma adjust
ence numerals as those therein, and the detailed description
thereof is omitted.
The input/ output terminal for external control 22 is used for
40
ment image 5 of each of R, G, and B. When R, G, and B are
tioned gamma adjustment to be read or rewritten from out
side. More speci?cally, data can be read to an externally
adjusted, the calculation results thereof are re?ected on a
controlling personal computer via the input/ output terminal
graph on the gamma adjustment image 5 of Y Regarding a
change in the input level, the change is limited to the gamma
adjustment image of Y so that the above-mentioned calcula
tion is made easy with R, G, and B being at the same input
level. It should be noted that an input level may be changed
individually for each of R, G, and B.
for external control 22 and the main microcomputer 17, using
45
a command for control by RS-232C, and the read data can be
rewritten to another device.
50
As described above, according to the present embodiment,
gamma adjustment value data can be exchanged easily among
users, for example, adjustment value data of the adjusted
results can be copied to another image display apparatus,
using a tool for controlling the image display apparatus 1b
The adjustment point 711 can be changed by pressing
another operation button of the remote controller 3 or by an
on-screen menu. In the ?gures, nine adjustment points 7 are
from outside.
shown; however, the present invention is not limited thereto
The projector that is the image display apparatus of
as long as there is no issue with a memory capacity. The
Embodiment 1 or 2 con?gured as described above canbe used
in a form as shown in FIG. 8. In FIG. 8, a projector 30
adjustment results are stored in the adjustment value storage
memory 19 such as an EEPROM by the main microcomputer
17. A memory capacity can be saved if the storage of data of
55
the adjustment points 7 is performed only for input signal
levels, R adjustment values, G adjustment values, and B
panel to display it on the screen 14 in an enlarged state. The
adjustment values of the 9 adjustment points 7, and when
reading data from the memory, RGBQYCbCr conversion is
performs signal processing inside with respect to a video
signal from a BD player 31 connected to a picture input
terminal, and develops the video signal onto a liquid crystal
60
adjustment of an image is performed by the remote controller
3 or the operation buttons 20 of the main body. Further, using
calculated with respect to Y adjustment values. By assigning
a tool for controlling the device on a personal computer 32
a plurality of adjustment results to the adjustment value stor
connected to an input terminal for external control, the adjust
age memory 19 so that they are stored separately, data can be
ment value data can be read to the tool and the adjustment
value data can be rewritten to the main body of the device.
read easily.
FIG. 5 is a ?ow chart of main microcomputer processing at
a time of gamma adjustment of the image display apparatus in
the present embodiment.
65
As described above, according to the image display appa
ratus and the image display method of the present invention,
the gamma adjustment in the image display apparatus such as
US 8,743,289 B2
8
7
3. The image display apparatus according to claim 2, con
a projector can be performed when a user changes an input
level and an output level of a video signal. Thus, the adjust
ment can be performed easily, freely, and in detail.
The invention may be embodied in other forms without
departing from the spirit or essential characteristics thereof.
?gured in such a manner that data of the stored input/ output
level is read and rewritten via an input/ output terminal
The embodiments disclosed in this application are to be con
wherein the adjustment operation unit is capable of perform
sidered in all respects as illustrative and not limiting. The
ing an operation of changing an input level and an output level
with respect to Y (luminance).
enabling control from outside.
4. The image display apparatus according to claim 1,
scope of the invention is indicated by the appended claims
5. The image display apparatus according to claim 1,
wherein the adjustment operation unit is capable of perform
rather than by the foregoing description, and all changes
which come within the meaning and range of equivalency of
ing an operation of changing an input level and an output level
with respect to any monochrome of R, G, and B.
6. The image display apparatus according to claim 1, com
the claims are intended to be embraced therein.
What is claimed is:
1. An image display apparatus, comprising:
prising a freeze processing circuit enabling adjustment of the
input/output characteristics while freeZing a moving image
a picture display unit that forms and displays an optical
image based on a video signal;
signal.
a gamma adjustment image display unit that displays a
7. An image display method, comprising:
gamma adjustment image containing input/output char
forming and displaying an optical image based on a video
acteristics of a signal level of the video signal in the
signal;
displayed optical image;
an adjustment operation unit that changes the displayed
input/output characteristics on the image; and
an input/output characteristics setting unit that sets input/
output characteristics of the signal level of the video
signal in accordance with the input/output characteris
tics changed on the image,
wherein input levels of a plurality of adjustment points are
preset to ?xed reference values, and
20
output characteristics of a signal level of the video signal
in the displayed optical image;
changing the displayed input/output characteristics on the
25
the adjustment operation unit includes a point selecting
part that selects one of the adjustment points desired to
be changed in the input/output characteristics displayed
30
selected ?xed reference value.
2. The image display apparatus according to claim 1, com
prising an adjustment value storage memory capable of stor
ing and reading data of the changed input/ output level.
image; and
setting the input/ output characteristics of the signal level of
the video signal in accordance with the input/ output
characteristics changed on the image,
wherein, input levels of a plurality of adjustment points are
preset to ?xed reference values, and
when the input/output characteristics are changed on the
image, one of the adjustment points desired to be
in the image and a level changing part that is capable of
changing both of the input level and an output level of
the selected adjustment point, in which the input level
can be changed from one of the ?xed reference values to
an intermediate value between the selected ?xed refer
ence value and a ?xed reference value adjacent to the
displaying a gamma adjustment image containing input/
changed in the input/ output characteristics displayed in
35
the image is selected, and both of an input level and an
output level of the selected adjustment point are
changed, in which the input level can be changed from
one of the ?xed reference values to an intermediate value
between the selected ?xed reference value and a ?xed
reference value adjacent to the selected ?xed reference
value.
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