NOH, Yo-Hwan (203-302, Samick Hanmaeul Mansion739-15,Bono 2-dong, Sangnok-gu, Ansan-si, Gyeonggi-do 426-182, KR)
| [CLAIMS]
[Claim 1 ]
An apparatus correcting the brightness of an image by using a correction curve,
the apparatus comprising:
an image input unit, receiving an image;
a correction gradient selection unit, selecting a gradient of the correction curve
corresponding to an object pixel, having the brightness desired to be corrected, of pixels
of the image;
a correction performance unit, converting original brightness of the object pixel
into correction brightness according to the correction curve having the selected gradient;
and
an image output unit, outputting the image allowing the object pixel to have the
correction brightness by the correction performance unit;
whereas the correction curve increases the contrast of the corresponding
correction brightness if the original brightness is the same as or smaller than a
predetermined brightness, and the correction curve decreases the contrast of the
corresponding correction brightness if the original brightness is larger than a
predetermined brightness.
[Claim 2] The apparatus of Claim 1 , wherein the correction gradient selection unit selects
the gradient to increase the contrast of the corresponding brightness according to the
position relationship between a center pixel of the image and the object pixel if the
original brightness is the same as or smaller than the predetermined brightness.
[Claim 3]
The apparatus of Claim 1, wherein the correction curve is the same as or larger
than 1 if the original brightness is the same as or smaller than the predetermined
brightness and is smaller than 1 if the original brightness is larger than the
predetermined brightness.
[Claim 4]
The apparatus of Claim 1 , wherein the correction curve is represented in a form
of a lookup table for the relationship between the original brightness and the correction
brightness.
[Claim 5]
The apparatus of Claim 1 , wherein in the correction curve, the correction
brightness is the same as or larger than a predetermined value. [Claim 6]
The apparatus of Claim 1, wherein the correction gradient selection unit allows
the correction curve to have different gradients whenever the distance between the
center pixel and the object pixel of the image is integer numbers times as many as
predetermined pixel numbers.
[Claim 7]
A method correcting the brightness of an image by using a correction curve,
the method comprising:
(a) receiving an image;
(b) selecting an object pixel, having the brightness desired to be corrected, of
pixels of the image;
(c) selecting a gradient of the correction curve corresponding to the object
pixel;
(d) converting original brightness of the object pixel into correction brightness
according to the correction curve having the selected gradient; and
(e) outputting the image allowing the object pixel to have the correction
brightness,
whereas the correction curve increases the contrast of the corresponding correction brightness if the original brightness is the same as or smaller than a
predetermined brightness, and the correction curve decreases the contrast of the
corresponding correction brightness if the original brightness is larger than a
predetermined brightness.
[Claim 8]
The method of Claim 7, wherein the step (c) selects the gradient to increase the
contrast of the corresponding brightness according to the position relationship between
a center pixel of the image and the object pixel if the original brightness is the same as
or smaller than the predetermined brightness .
[Claim 9]
The method of Claim 7, wherein the correction curve is the same as or larger
than 1 if the original brightness is the same as or smaller than the predetermined
brightness and is smaller than 1 if the original brightness is larger than the
predetermined brightness.
[Claim 10]
The method of Claim 7, further comprising repeating the steps (b) through (d)
until all pixels of the image are selected as the object pixel before the step (e). [Claim 11 ]
The method of Claim 7, wherein the correction curve is represented in a form
of a lookup table for the relationship between the original brightness and the correction
brightness.
[Claim 12]
The method of Claim 7, wherein in the correction curve, the correction
brightness is the same as or larger than a predetermined value.
[Claim 13]
The method of Claim 7, wherein the step (b) allows the correction curve to
have different gradients whenever the distance between the center pixel and the object
pixel of the image is integer numbers times as many as predetermined pixel numbers.
[Claim 14]
A recording medium tangibly embodying a program of instructions executable
by a digital processing apparatus to correct the brightness of an image, the recording
medium being readable by the digital processing apparatus, the program comprising:
(a) receiving an image; (b) selecting an object pixel, having the brightness desired to be corrected, of
pixels of the image;
(c) selecting a gradient of the correction curve corresponding to the object
pixel;
(d) converting original brightness of the object pixel into correction brightness
according to the correction curve having the selected gradient; and
(e) outputting the image allowing the object pixel to have the correction
brightness,
whereas the correction curve increases the contrast of the corresponding
correction brightness if the original brightness is the same as or smaller than a
predetermined brightness, and the correction curve decreases the contrast of the
corresponding correction brightness if the original brightness is larger than a
predetermined brightness. |
[DESCRIPTION]
[Invention Title]
IMAGE BRIGHTNESS COMPENSATING APPARATUS AND METHOD,
RECORDED MEDIUM RECORDED THE PROGRAM PERFORMING IT
[Technical Field]
The present invention relates to an image sensor, more specifically, an
apparatus and a method of smoothing the brightness of an image photographed by an
image sensor without amplifying a noise component of a surrounding part of the image.
[Background Art]
An image sensor refers to the semiconductor device converting an optical
image into an electric signal. Among this, a charge coupled device (CCD) refers to the
device in which individual metal-oxide-silicon (MOS) capacitors are placed very close
to each other and charge carriers are stored in and transmitted to the capacitors.
However, a complementary MOS (CMOS) image sensor refers to the device employing
a switching method, which makes as many MOS transistors as the number of pixels by
using the CMOS technology using a control circuit and a signal processing circuit as a
peripheral circuit and successively detects the output of the pixels by using the MOS
transistors.
Portable apparatuses (e.g. digital cameras and mobile communication terminal)
having image sensors are now developed and on sale. The image sensor consists of the
arrays of small photo diodes, which are called pixel or photosite. The pixels themselves
typically do not extract color from light. The pixels merely convert photos, provided
from a wide spectrum band, into electrons. To write a color image by using a single
sensor, a sensor is filtered such that different pixels can receive different color light.
This type of sensor is well-known as a color filter array (CFA). The different color
filters intersect the sensor and are arrayed in a predetermined pattern.
A color filter array of a color image typically is typically adjusted to the Bayer
pattern. In other words, the half of total numbers of pixels is assigned to green G. Each
quarter of the total numbers is assigned to red R and blue B. To get color information,
color image pixels has a pattern repeated with red, green, and blue filters. For example,
the Bayer pattern has a 2 x 2 array.
The Bayer pattern is based on the premise that a user's eye derives most of
luminance data from the green component of an image. Accordingly, the RGB color
filter alternated with more green pixels than other color pixels can generate a higher
contrast image than the RGB color filter alternated with the same ratio of red, green and
blue pixels.
The first one of elements directly related to the image quality of the image
sensor is the lens concentrating light on the image sensor. The lens is required to have
the properties such as good concentration of the focus point of light on the image sensor,
penetration of more amount of light and uniform permeability of light into whole
photographing surface.
A recently developed and purchased portable apparatus has the trends toward
slim appearance and miniaturization, which mean all sensor modules become slim and
compact. Accordingly, a corresponding image sensor equipped in the portable apparatus
is required to have high resolution. As a result, enough distance is not acquired between
a lens and a photographed surface. The brightness of the lens is not bright enough. The
permeability of the lens is not uniform. In particular, the more distant the lens is toward
an outside, the less the amount of light becomes.
FIG. 1 illustrates an image of an image sensor and an area thereof having
different features, FIG. 2 illustrates features of an image per area and FIG. 3 illustrates a
method of compensating features of an image per area.
Referring to FIG. 1, the feature of the image 100 is typically changed in the
direction from a center pixel 110 of a center part thereof toward each edge pixel 120a,
120b, 120c and 12Od (hereinafter, collectively referred to as 120). In other words,
portions having similar features can be recognized by each concentric ring 130a, 130b,
130c and 130d.
FIG. 2 shows the brightness, depending on the position of a pixel in the image
100, of various features. A first curve 210 indicates the maximum brightness depending
on each pixel, and a second curve 220 indicates the minimum brightness depending on
each pixel. The first curve 210 and the second curve 220 are brightest in the center pixel
110 and darkest in the edge pixel 120. The brightness of pixels get lower as the pixel
position is changed from the center pixel to the edge pixel.
If a dynamic range D 1 of the center pixel 110 is compared with dynamic
ranges Dl and D2 of the edge pixels 120, the dynamic range Dl of the center pixel 110
is wider. Here, the dynamic range refers to the difference between the darkest brightness
and the brightest brightness capable of being expressed in a corresponding pixel. In
other words, the wide dynamic range leads to the high contrast, and the narrow dynamic
range leads the low contrast.
If the dynamic range Dl of the center pixel 110 is compared with dynamic
ranges Dl and D2 of the edge pixels 120, the difference occurs from 30 to 40 % at the
maximum depending on the lens feature of the image sensor. When it comes to the
brightness, the surrounding parts having the edge parts 120 are easily affected by the
noise relatively as compared with the center part having the center pixel 110.
Accordingly, the compensation is needed.
For the compensation, referring to FIG. 3, the dynamic ranges of the whole
image are attempted to be smoothed based on the dynamic range of the center pixel 110
(referring to a first arrow 310 and a second arrow 320). Accordingly, the dynamic range
D2 of the surrounding part (having the edge pixel 120) is changed into D2'. For this, a
gain of a certain rate is multiplied or a device performing a lens shading compensation
function is used in order to compensate the dynamic ranges of the whole image.
However, in this case, the noise component is amplified together in the surrounding part
having the edge pixel 120, to thereby lower the contrast in the surrounding parts of the
image 100 and deteriorate the quality of the image 100.
[Disclosure]
[Technical Problem]
Accordingly, the present invention provides an image brightness correction
apparatus and a method thereof, and a recoding medium recorded with a program
performing the method that can smooth the brightness of a whole image without
amplifying a noise component of a surrounding part of the image.
[Technical Solution]
To solve the above problems, according to an aspect of the present invention,
there can be provided an apparatus correcting the brightness of an image by using a
correction curve, including an image input unit, receiving an image; a correction
gradient selection unit, selecting a gradient of the correction curve corresponding to an
object pixel, having the brightness desired to be corrected, of pixels of the image; a
correction performance unit, converting original brightness of the object pixel into
correction brightness according to the correction curve having the selected gradient; and
an image output unit, outputting the image allowing the object pixel to have the
correction brightness by the correction performance unit; whereas the correction curve
increases the contrast of the corresponding correction brightness if the original
brightness is the same as or smaller than a predetermined brightness, and the correction
curve decreases the contrast of the corresponding correction brightness if the original
brightness is larger than a predetermined brightness.
Preferably, the correction gradient selection unit can select the gradient to
increase the contrast of the corresponding brightness according to the position
relationship between a center pixel of the image and the object pixel if the original
brightness is the same as or smaller than the predetermined brightness.
Also, the correction curve can be the same as or larger than 1 if the original
brightness is the same as or smaller than the predetermined brightness and is smaller
than 1 if the original brightness is larger than the predetermined brightness.
The correction curve can be represented in a form of a lookup table for the
relationship between the original brightness and the correction brightness.
In the correction curve, the correction brightness can be the same as or larger
than a predetermined value.
The correction gradient selection unit can allow the correction curve to have
different gradients whenever the distance between the center pixel and the object pixel
of the image is integer numbers times as many as predetermined pixel numbers.
To solve the above problems, according to another aspect of the present
invention, there can be provided a method correcting the brightness of an image by
using a correction curve, including (a) receiving an image; (b) selecting an object pixel,
having the brightness desired to be corrected, of pixels of the image; (c) selecting a
gradient of the correction curve corresponding to the object pixel; (d) converting
original brightness of the object pixel into correction brightness according to the
correction curve having the selected gradient; and (e) outputting the image allowing the
object pixel to have the correction brightness, whereas the correction curve increases the
contrast of the corresponding correction brightness if the original brightness is the same
as or smaller than a predetermined brightness, and the correction curve decreases the
contrast of the corresponding correction brightness if the original brightness is larger
than a predetermined brightness.
Preferably, the step (c) can select the gradient to increase the contrast of the
corresponding brightness according to the position relationship between a center pixel
of the image and the object pixel if the original brightness is the same as or smaller than
the predetermined brightness.
Further, the correction curve can be the same as or larger than 1 if the original
brightness is the same as or smaller than the predetermined brightness and can be
smaller than 1 if the original brightness is larger than the predetermined brightness.
The method can further include repeating the steps (b) through (d) until all
pixels of the image are selected as the object pixel before the step (e).
The correction curve can be represented in a form of a lookup table for the
relationship between the original brightness and the correction brightness.
In the correction curve, the correction brightness can be the same as or larger
than a predetermined value.
The step (b) can allow the correction curve to have different gradients
whenever the distance between the center pixel and the object pixel of the image is
integer numbers times as many as predetermined pixel numbers.
To solve the above problems, according to another aspect of the present
invention, there can be provided a recording medium tangibly embodying a program of
instructions executable by a digital processing apparatus to correct the brightness of an
image, the recording medium being readable by the digital processing apparatus, the
program including (a) receiving an image; (b) selecting an object pixel, having the
brightness desired to be corrected, of pixels of the image; (c) selecting a gradient of the
correction curve corresponding to the object pixel; (d) converting original brightness of
the object pixel into correction brightness according to the correction curve having the
selected gradient; and (e) outputting the image allowing the object pixel to have the
correction brightness, whereas the correction curve increases the contrast of the
corresponding correction brightness if the original brightness is the same as or smaller
than a predetermined brightness, and the correction curve decreases the contrast of the
corresponding correction brightness if the original brightness is larger than a
predetermined brightness.
Other problems, certain benefits and new features of the present invention will
become more apparent through the following description with reference to the
accompanying drawings and some embodiments.
[Description of Drawings]
FIG. 1 illustrates an image of an image sensor and an area thereof having
different features;
FIG. 2 illustrates features of an image per area;
FIG. 3 illustrates a method of compensating features of an image per area;
FIG. 4 is a block diagram briefly illustrating an image brightness correction
apparatus in accordance with an embodiment of the present invention;
FIG. 5 illustrates an example of a correction curve in accordance with an
embodiment of the present invention;
FIG. 6 illustrates an example of a correction curve changed according to the
position of an object pixel in accordance with an embodiment of the present invention;
FIG. 7 illustrates an example of a correction curve changed according to the
position of an object pixel in accordance with another embodiment of the present
invention; and
FIG. 8 is a flow chart illustrating an image brightness correction method in
accordance with an embodiment of the present invention.
[Mode for Invention]
Hereinafter, some embodiments of an image brightness correction apparatus
and a method thereof, and a recoding medium recorded with a program performing the
method in accordance with the present invention will be described in detail with
reference to the accompanying drawings. Throughout the description of the present
invention, when describing a certain technology is determined to evade the point of the
present invention, the pertinent detailed description will be omitted. Terms (e.g. "first"
and "second") used in this description merely are identification for successively
identifying identical or similar elements.
FIG. 4 is a block diagram briefly illustrating an image brightness correction
apparatus in accordance with an embodiment of the present invention, and FIG. 5
illustrates an example of a correction curve in accordance with an embodiment of the
present invention.
The image brightness correction apparatus 400 includes an image input unit
410, a correction gradient selection unit 420, a correction performance unit 430 and an
image output unit 440.
The image input unit 410 receives an image having a brightness desired to be
corrected. The image is assumed to have the same property as illuminated in FIG. 1. In
other words, a surrounding part of an image is darker than a center part by the lens
property of the image sensor.
The correction gradient selection unit 420 selects an object pixel, having a
brightness desired to be corrected, of each pixel of the image inputted into the image
input unit 410. Also, the correction gradient selection unit 420 selects a gradient of a
correction curve for correcting the brightness of the selected object pixel. The correction
curve is predetermined, and the gradient of the correction curve is changed according to
the obj ect pixel .
Alternatively, a different correction curve can be selected according to the
selected object pixel. A plurality of correction curves can be predetermined, and any
one of the plurality of correction curves can be selected according to the objected pixel.
The correction curve has information related to correction brightness
corresponding to the original brightness of the object pixel. For example, in the case of
having a contrast of n bits, n being a natural number, the original brightness has a value
between 0 and 2 n -l. The correction brightness also has the contrast of n bits and a value
between 0 and 2 n -l. In this case, the correction curve allows the original brightness
having a certain value to correspond with the correction brightness having the same or
different value.
While a person's eye can typically distinguish minute difference in a dark area,
the person's eye is not able to distinguish minute difference in a bright area.
Accordingly, in order to increase the contrast of an image, a dark area of the original
brightness is wider than that of the correction brightness. A bright area of the original
brightness is narrower than that of the correction brightness.
Referring to FIG. 5, an image is assumed to have the contrast of 8 bits. If the
original brightness has a value between 0 and Bl, since the correction brightness by a
correction curve 510 has a value between 0 and BI l and Bl 1 is larger than Bl, a dark
area of the original brightness is wider than that of the correction brightness. Also, in
this area, the gradient of the correction curve is the same as or larger than 1. This means
that it becomes easier to distinguish the difference in the area where the correction
brightness of the image is darker than the original brightness. If the original brightness
is the same as or smaller than Bl, the corresponding correction brightness is the same as
or smaller than BI l. Since B 1 is the same as or smaller than B 11 , the contrast (i.e. the
difference between the maximum value and the minimum value = Bl 1) of the
correction brightness is higher than the contrast (i.e. the difference between the
maximum value and the minimum value = Bl) of the original brightness.
If the original brightness has a value between Bl and 255, since the correction
brightness by the correction curve 510 has a value between BI l and 255 and B 11 is
larger than Bl, a bright area of the original brightness is narrower than that of the
correction brightness. Also, in this area, the gradient of the correction curve 510 is
smaller than 1. If the original brightness is the same as or larger than Bl, the
corresponding correction brightness is the same as or larger than BI l. Since Bl is the
same as or smaller than BI l, the contrast (i.e. 255-B11) of the correction brightness is
smaller than the contrast (i.e. 255-B1) of the original brightness. The correction curve
510 increases the contrast of the correction brightness (the gradient of the correction
curve 510 is the same as or larger than 1) in case that the original brightness has the
same as or smaller value than a predetermined brightness (e.g. Bl in the case of FIG. 5)
and decreases the contrast of the correction brightness (the gradient of the correction
curve 510 is smaller than 1) in case that the original brightness has a larger value than a
predetermined brightness (e.g. Bl in the case of FIG. 5).
While one correction curve is used for the whole image, the gradient of the
correction curve can be varied depending on an area where an object pixel is located in
the image. Alternatively, various correction curves can be used depending on an area
where an object pixel is located in the image. Since it is very likely that the surrounding
part of the image is darker than the center part of the image, if the object pixel is located
at the surrounding part of the image, the contrast of the dark area is increased more than
the case that the object pixel is located at the center part of the image.
The correction performance unit 430 converts the original brightness of the
object into corresponding correction brightness by using a correction curve having a
gradient selected in the correction gradient selection unit 430.
The image output unit 440 outputs an image allowing the object pixel to have
the correction brightness by the correction performance unit 430.
As one of good examples, before the image output unit 440 outputs the image
having the corrected brightness, the object pixel is allowed to have the correction
brightness instead of the original brightness by allowing the correction performance unit
430 to perform the correction according to the correction curve, selected by the
correction gradient selection unit 420, for all pixels of the image.
FIG. 6 illustrates an example of a correction curve changed according to the
position of an object pixel in accordance with an embodiment of the present invention.
FIG. 6 illustrates a first correction curve 510 used in a center part of an image
and a second correction curve 610 used in a surrounding part of the image, which have a
similar type to a gamma curve typically used in the gamma correction. The second
correction curve 610 can be generated by increasing the gradient of the first correction
curve 510 more. In other words, since the correction brightness corresponding to the
same original brightness B2 is B22 and B21 in the second correction curve 610 and the
first correction curve 510, respectively, there occurs the difference between B22 and
B21. This means that by allowing the second correction curve 610 to have a larger
gradient than the first correction curve 510, it is possible to correct the second
correction curve 610 so as to increase the contrast of the area, where the original
brightness is dark, and thus to have a clearer image.
In other words, by changing the gradient of the correction curve according to
the position relationship between a center pixel and an object pixel of the image, the
brightness correction is differently performed in the center part and the surrounding part
of the image, respectively. Since it is very likely that the surrounding part of the image
is darker than the center part, the discrimination can be increased by allowing the area,
where the original brightness is dark, to have the high contrast after correction.
As a shading curve for compensating lens shading goes toward edge parts
based on a center pixel, the shading curve increasingly has a larger value. A recent
portable apparatus has the trends toward slim appearance and miniaturization, which
mean all sensor modules become slim and compact. Accordingly, a corresponding
image sensor equipped in the portable apparatus is required to have the high resolution.
As a result, enough distance is not acquired between a lens and a photographed surface.
The brightness of the lens is not bright enough. The permeability of the lens is not
uniform. In particular, there eminently appears a lens shading phenomenon, which the
more distant the lens is toward an outside, the less the amount of light becomes. As it is
getting more distant toward the outside based on the center pixel, it becomes dark due to
reducing the amount of light. Accordingly, the shading curve has a convex shape toward
the bottom showing that a compensation value becomes increasing as it is getting close
to the edge part in order to suitably compensate the brightness of the whole image.
Thus, the gradient of the correction curve can be adjusted according to the
same type of shading curve. Since the shading curve functions to compensate the
brightness of pixels, it can be inferred that the larger a compensation value of the
shading curve, the larger gain is multiplied to compensate the brightness of pixels.
Accordingly, in accordance with another embodiment of the present invention, selecting
the gradient of the correction curve according to the position of the object pixel is
performed corresponding to the shading curve.
FIG. 7 illustrates an example of a correction curve changed according to the
position of an object pixel in accordance with another embodiment of the present
invention.
FIG. 7 (a) illustrates a first correction curve 510 used in a center part of an
image, which has a similar type to a gamma curve typically used in the gamma
correction.
FIG. 7 (b) illustrates a third correction curve 710 and a fourth correction curve
720 used in the surrounding part of the image. In the case of the third correction curve
710, the correction brightness of the object pixel is the same as or larger than a
predetermined value (e.g. B3 in this case). In the case of the fourth correction curve 720,
when the original brightness of the object brightness is the same as or smaller than a
predetermined value (e.g. B4 in this case), the correction brightness is set as 0.
In accordance with another embodiment of the present invention, in the case of
the third correction curve 710, the same effect as if an offset placed in the correction
brightness is removed after correcting the original brightness is taken. In other words,
the correction brightness by the third correction curve 710 is allowed to have a value
which is the same as or larger than B3 in a lump by applying a certain rate to the
correction brightness after the correction is performed by the first correction curve 510.
In accordance with another embodiment of the present invention, in the case of
the fourth correction curve 720, the same effect as if the correction is performed after
removing an offset placed in the original brightness is taken. In other words, the original
brightness by the third correction curve 710 is allowed to have a value which is the
same as or larger than B4 in a lump or by applying a certain rate to the original
brightness before the correction is performed by applying the first correction curve 510.
By using the same curve as the correction curves 710 and 720, it is possible to
differentiate brightness correction levels in the center part and the surrounding part of
the image and to correct the phenomenon that the surrounding part of the image is likely
to be darker than the center part, without amplifying noise.
In accordance with another embodiment of the present invention, the correction
curve can be represented in a form of a lookup table. This means that the correction
brightness corresponding to the original brightness at regular intervals is stored as the
lookup table and it is possible to determine the correction brightness by an interpolation
method for the original brightness therebetween.
Alternatively, the correction curve of the present invention can have different
gradients or different correction curves can be selected whenever the distance between
the center pixel and the object pixel of the image is integer numbers times as many as
predetermined pixel numbers (e.g. 16 pixels and 32 pixels). This makes an operation
speed more quickly and the load of a processor less in the correction operation as
compared with the case of setting different gradients or different correction curves for
all pixels of the image.
FIG. 8 is a flow chart illustrating an image brightness correction method in
accordance with an embodiment of the present invention.
A step represented by S810 receives an image of the brightness desired to be
corrected.
A step represented by S820 selects an object pixel, having the brightness
desired to be corrected, of pixels of the inputted image. The selection of the object pixel
is to select the gradient of the same or different correction curve for correction
according to the position relationship between the center pixel and the object pixel of
the image.
A step represented by S830 allows the correction curve to have the gradient
corresponding to the object pixel. Since the correction curve has been described in
detail with reference to FIG. 5 through FIG. 7, the pertinent description will be omitted.
A step represented by S 840 converts original brightness of the object pixel into
correction brightness according to the correction curve having the selected gradient.
Here, the correction curve can be represented in a form of a lookup table, and the
correction brightness for the original brightness is predetermined.
All pixels of the image can be allowed to have the correction brightness in
which the brightness correction is performed by repeating the steps represented by S 820
through S840.
A step represented by S850 outputs an image in which the brightness
correction is performed.
In accordance with another embodiment of the present invention, a recording
medium tangibly embodying a program of instructions executable by a digital
processing apparatus to correct the brightness of an image, the recording medium being
readable by the digital processing apparatus, the program performing a brightness
correction method of the steps represented by S810 through S850 is recorded.
The recording medium of the present invention refers to the medium such as
CD-ROM, RAM, floppy disc, hard disc and magneto-optical disc capable of being read
by a computer and storing a program.
Hitherto, although some embodiments of the present invention have been
shown and described for the above-described objects, it will be appreciated by any
person of ordinary skill in the art that a large number of modifications, permutations and
additions are possible within the principles and spirit of the invention, the scope of
which shall be defined by the appended claims and their equivalents.
[Industrial Applicability]
As described above, in accordance with the present invention, an image
brightness correction method and a method thereof and a recording medium a recoding
medium recorded with a program performing the method can smooth the brightness of a
whole image without amplifying a noise component of a surrounding part of the image.
The present invention smoothes a dynamic range of an image and acquires the
contrast of the image.
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