Image analysis – Color image processing – Color correction
Reexamination Certificate
2000-06-27
2003-07-01
Tran, Phuoc (Department: 2621)
Image analysis
Color image processing
Color correction
C348S674000
Reexamination Certificate
active
06587584
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to an image correcting apparatus; and, more particularly, to an apparatus for gamma correcting image data, which is capable of reducing a chip size.
DESCRIPTION OF THE PRIOR ART
Generally, in a gamma correction of a red (R) image data D
RED
, a green (G) image data D
GREEN
, and a blue (B) image data D
BLUE
, each gamma corrected data is obtained by using exponential functions. However, it is difficult to correctly implement the exponential function by using hardware elements, and, if possible, a lot of hardware elements are required.
FIG. 1
is a block diagram showing a conventional gamma correction apparatus using lookup tables. The lookup tables stores gamma corrected data that are previously calculated. The lookup tables are stored in a storage unit such as ROM (read only memory) and RAM (random access memory).
As shown in
FIG. 1
, the conventional gamma correction apparatus includes a latch portion
100
for latching image data, a lookup table portion
108
for storing gamma corrected data with respect to the image data, and a gamma latch portion
116
for latching the gamma corrected data outputted from the lookup table portion
108
.
The latch portion
100
includes an R latch
102
for latching a red image data D
RED
, a G latch
104
for latching a green color image data D
GREEN
, and a B latch
106
for latching a blue color image data D
BLUE
.
The lookup table portion
108
includes a first lookup table
110
for storing a gamma corrected red image data, a second lookup table
112
for storing a gamma corrected green image data, and a third lookup table
114
for storing a gamma corrected blue image data.
The gamma latch portion
116
includes an R gamma latch
118
, a G gamma latch
120
, and a B gamma latch
122
. The R gamma latch
118
latches the gamma corrected red image data that are outputted from the first lookup table
110
. The G gamma latch
120
latches the gamma corrected green image data that are outputted from the second lookup table
112
. The B gamma latch
122
latches the gamma corrected blue image data that are outputted from the third lookup table
122
.
In such a conventional gamma correction apparatus, R, G, and G linear image data are latched to corresponding latch circuits
102
,
104
and
106
, respectively. Then, gamma corrected data corresponding to the linear image data is outputted from respective lookup tables. The gamma corrected data read out are latched and outputted to a next image processing circuit. Each gamma corrected data from the gamma latch portion
116
is transferred to a next image processing unit.
In such a conventional gamma correction apparatus, one image data is latched in a corresponding latch and a gamma corrected image data of corresponding image data is outputted to the gamma latch. Then, the gamma corrected image data stored in the gamma latch is outputted to a next image process unit.
However, since the conventional gamma correction apparatus employs individual lookup tables for storing the gamma corrected image data, the hardware elements for implementing the lookup tables are required, thereby increasing a chip size.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an apparatus for gamma correcting image data in an image sensor, capable of reducing a chip size.
In accordance with an aspect of the present invention, there is provided an apparatus for gamma correcting image data including a first image data, a second image data and a third image data, the apparatus comprising: a first clock generating means for generating a first clock; a second clock generating means for generating a second clock, wherein the second clock has a frequency a predetermined times as fast as the first clock; an image data input means for storing the image data in response to a first clock; a first selecting means for selectively outputting the image data in response to a second clock; a second selecting means for selectively outputting a starting point value of corresponding image data in response to the second clock; a third selecting means for selectively outputting a gamma slope value of corresponding image data in response to the second clock; a piecewise gamma correction means for receiving output values from the first, the second and the third selecting means to generate gamma corrected image data; and an output means for storing the gamma corrected image data a predetermined time and outputting the gamma corrected image data in response to the second clock.
REFERENCES:
patent: 4926247 (1990-05-01), Nagasaki et al.
patent: 4926251 (1990-05-01), Sekizawa et al.
patent: 5103299 (1992-04-01), Asaida
patent: 5325182 (1994-06-01), Murata et al.
patent: 5386304 (1995-01-01), Suzuki
patent: 5408267 (1995-04-01), Main
patent: 5463702 (1995-10-01), Trueblood
patent: 5473373 (1995-12-01), Hwung et al.
patent: 5532765 (1996-07-01), Inoue et al.
patent: 5764287 (1998-06-01), Tatsumi
patent: 6292165 (2001-09-01), Lin et al.
patent: 6344857 (2002-02-01), Matono et al.
patent: 4-205996 (1992-07-01), None
Hyundai Electronics Industries Co,. Ltd.
Jacobson & Holman PLLC
Tran Phuoc
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