KR100999218B1 - Apparatus For Processing Image Siganl, Method For Reducing Noise Of Image Signal Processing Apparatus And Recorded Medium For Performing Method Of Reducing Noise - Google Patents

Abstract

Disclosed is an image signal processing apparatus capable of maximally suppressing color noise generated during a color correction process of an image, a recording medium in which a color correction method and a color correction method of an image signal processing apparatus are recorded. The image signal processing apparatus performs color correction on the color interpolation unit for performing color interpolation on the image data provided from the image sensor and the color interpolated data, and obtains a luminance value based on the data on which color interpolation is performed. Thereafter, a color correction unit is set based on the obtained luminance value, and a color correction unit removes noise included in the color corrected data based on the set color correction intensity. Therefore, color noise generated in the color correction process can be efficiently removed, and in particular, color noise that can occur in dark areas of the image can be efficiently removed.

Image, noise, color correction, CSP, ISP, intensity, area

Description

Apparatus For Processing Image Siganl, Method For Reducing Noise Of Image Signal Processing Apparatus And Recorded Medium For Performing Method Of Reducing Noise}

The present invention relates to a signal processing device, and more particularly, to a recording medium in which an image signal processing device, a color correction method and a color correction method of an image signal processing device, which can be applied to a signal processing device for processing a captured image, are recorded. It is about.

Image sensors such as Charge Coupled Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS) are composed of two-dimensional integrated pixels and convert electrical signals corresponding to the brightness of incident light into digital signals. To print. Here, the image sensor may be configured in a Bayer pattern, and provides Bayer image data corresponding to brightness of light incident on the Bayer pattern.

Batter image data provided from an image sensor is output as a luminance signal and a color difference signal through various signal processing such as color interpolation, luminance processing, color processing, color format conversion, and the like through an image signal processing apparatus.

1 is a block diagram showing the configuration of a general image signal processing apparatus.

Referring to FIG. 1, a general image signal processing apparatus includes a raw data processor 10, a color interpolator 20, a color corrector 30, a gamma corrector 40, and a format converter 50.

The raw data processing unit 10 receives raw data (RAW), that is, Bayer image data of a Bayer pattern, from an image sensor, and shading caused by defect correction or short focal length of a lens present in the image sensor. Perform preprocessing such as shading correction.

The color interpolator 20 receives data preprocessed by the raw data processor 10, and interpolates each pixel component having one channel component through R (Red), G (Green), After separation into B (Blue) components, these pixels are combined to generate image data in which each pixel has three channel components of R, G, and B.

The image data output from the color interpolator 20 includes a lot of mixed colors. The color correction unit 30 approximates the spectral characteristics of the image data to the sRGB or Adobe RGB spectral characteristics so that the image data provided from the color interpolation unit 20 is an output close to the sRGB or Adobe RGB standard, which is a standard color space. Correct it to

The gamma correction unit 40 non-linearly transforms the intensity signal of the light by using a nonlinear transfer function in consideration of the fact that human vision reacts non-linearly to brightness.

The format converter 50 converts the image data of the RGB region into a Y component, which is a luminance component, and a Cb and Cr component, which is a chrominance component.

However, in the conventional image signal processing apparatus as shown in FIG. 1, since the color correction unit 30 performs color correction on the entire RGB image provided from the color interpolation unit 20, the image correction unit 30 performs a color correction in the dark region of the image. Inadvertent color noise (color noise) is a disadvantage that occurs.

In particular, since the color noise generated in the dark area of the image as shown above is in a stained shape, there is a problem in that it is more difficult to see than the color noise included in the bright part of the image.

Accordingly, a first object of the present invention is to provide an image signal processing apparatus capable of maximally suppressing color noise generated during a color correction process.

In addition, a second object of the present invention is to provide a color correction method capable of maximally suppressing color noise generated in the color correction process.

Further, a third object of the present invention is to provide a recording medium on which a color correction method is recorded, which can suppress color noise generated in the color correction process to the maximum.

An image signal processing apparatus according to an aspect of the present invention for achieving the first object of the present invention described above comprises a color interpolation unit for performing color interpolation on image data provided from an image sensor and a data interpolation unit. Perform color correction on the color, obtain a luminance value based on the data on which the color interpolation is performed, set a color correction intensity based on the obtained luminance value, and perform color correction on the basis of the set color correction intensity. It includes a color correction unit for removing the noise contained in the data. The color correction unit may include a color reproducing unit performing color correction on the data on which the color interpolation has been performed, a luminance signal generating unit obtaining a luminance value based on the data on which the color interpolation has been performed, and the obtained luminance value. A color correction intensity generation unit for setting a color correction intensity to a value corresponding to the luminance value among a value between a preset maximum intensity value and a preset minimum intensity value when smaller than a preset area boundary value, and based on the set color correction intensity It may include a noise removing unit for removing the noise contained in the color-corrected data. The color correction intensity generation unit may set the color correction intensity as the minimum intensity value when the obtained luminance value is equal to or greater than a preset area boundary value. The color correction intensity generating unit may be represented by a formula: Strength = ((threshold-Y _i ) × Str1 + Y _i × Str2) / threshold), where Strength is the color correction intensity, threshold is an area boundary value, and Str1 is the maximum intensity. Value, Str2 is the minimum intensity value, and Y _i represents the luminance value). The noise removing unit removes noise from data values corresponding to the color correction intensity among values between data values obtained by color correction provided from the color reproduction unit and data values obtained by color interpolation provided from the color interpolation unit. By acquiring the data, noise included in the color corrected data may be removed. The noise removing unit is expressed by the formula R _o = ((Norm-Strength) × R _c + Strength × R _i ) / Norm, G _o = ((Norm-Strength) × G _c + Strength × G _i ) / Norm, B _o = ((Norm-Strength) × B _c + Strength × B _i ) / Norm (where R _o , G _o and B _o are the noise reduction data, R _c , G _c and B _c are determined by the color correction The obtained data values, R _i , G _i and B _i are data values obtained by the color interpolation, Strength means color correction intensity, and Norm means normalization variable. Can be removed.

In addition, the color correction method according to an aspect of the present invention for achieving the second object of the present invention, performing a color interpolation on the image data provided from the image sensor, and based on the data on which the color interpolation is performed Obtaining a luminance value, performing color correction on the color interpolated data, and when the obtained luminance value is smaller than a preset area boundary value, the color correction intensity is preset to a maximum intensity value and a preset value. Setting a value corresponding to the luminance value among values among the set minimum intensity values and removing noise included in the color corrected data based on the set color correction intensity. The color correction method may further include setting the color correction intensity to the minimum intensity value when the obtained luminance value is greater than or equal to a preset area boundary value. When the obtained luminance value is smaller than a preset area boundary value, setting the color correction intensity to a value corresponding to the luminance value from among values between a preset maximum intensity value and a preset minimum intensity value, = ((threshold-Y _i ) × Str1 + Y _i × Str2) / threshold) (where Strength is the color correction intensity, threshold is an area boundary value, Str1 is the maximum intensity value, Str2 is the minimum intensity value, Y _i denotes the luminance value). The step of removing noise included in the color corrected data based on the set color correction intensity may be performed based on the color correction intensity from among values between the data value obtained by the color correction and the data value obtained by the color interpolation. The noise included in the color corrected data may be removed by acquiring a corresponding data value as the noise removing data. The step of removing noise included in the color corrected data based on the set color correction intensity may be performed by the following equation: Ro = ((Norm-Strength) × Rc + Strength × Ri) / Norm, Go = ((Norm-Strength) × Gc + Strength × Gi) / Norm, Bo = ((Norm-Strength) × Bc + Strength × Bi) / Norm (where R _o , G _o , B _o are the noise reduction data, R _c , G _c , B _c is the data value obtained by the color correction, R _i , G _i , B _i is the data value obtained by the color interpolation, Strength is the color correction intensity, Norm means a normalization variable) Noise included in the corrected data can be removed.

In addition, the recording medium recorded with the color correction method according to an aspect of the present invention for achieving the third object of the present invention is to perform a color interpolation on the image data provided from the image sensor, and the color interpolation is performed Acquiring a luminance value based on data, performing color correction on the data on which color interpolation is performed, and when the obtained luminance value is smaller than a preset area boundary value, a color correction intensity is preset to a maximum value. A program for setting a value corresponding to the luminance value among the value between the intensity value and the preset minimum intensity value and removing noise included in the color corrected data based on the set color correction intensity do.

The image signal processing apparatus, according to the color correction method and a color-correcting method is recorded the recording medium in the image signal processing apparatus, as provided by the color correction portion color interpolating interpolated data (R _i, G _i, B _i), such as the color is adaptively based on the after base to generate a luminance value (Y _i), and based on the region border value provided by the system separates the luminance (Y) into two regions the generated luminance value (Y _i) After generating the correction intensity value, the color noise generated in the color correction process is removed based on the generated color correction intensity value.

Therefore, color noise generated in the color correction process can be efficiently removed, and in particular, color noise that can occur in dark areas of the image can be efficiently removed.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. In the following description of the present invention, the same reference numerals are used for the same elements in the drawings and redundant descriptions of the same elements will be omitted.

FIG. 2 is a block diagram illustrating a configuration of an image signal processing apparatus according to an exemplary embodiment of the present invention, and descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention are omitted.

2, the image signal processing apparatus may include a preprocessor 100, a color interpolator 200, and a color corrector 300.

The preprocessing unit 100 performs shading correction caused by defect correction and / or short focal length of the lens on the Bayer image data provided from the image sensor.

The color interpolator 200 separates each pixel component included in the Bayer image data into R (Red), G (Green), and B (Blue) components through interpolation, and combines the pixels to combine the pixels. R, G, and then generate image data having the three-channel component of B, the resulting data (R _i, G _i, B _i) and provides the color correction section 300.

The color corrector 300 generates a luminance value Y _i based on the interpolated data Ri, Gi, Bi provided from the color interpolator 200, and generates a luminance value ( _i ) based on an area boundary value provided from the system. After dividing Y) into two regions, adaptively generating a color correction intensity value based on the generated luminance value Y _i and then correcting the color based on the generated color correction intensity value Eliminate color noise generated in the process.

In detail, the color corrector 300 may include a color reproducer 310, a luminance signal generator 330, a color correction intensity generator 350, and a noise remover 370.

Color reproduction gain to the color reproducing unit 310 includes a color interpolator 200. The data (R _i, G _i, B _i) interpolated data (R _i, G _i, B _i) provided under, provide interpolated from ( By multiplying the color reproduction gain, the spectral characteristics of the interpolated data are corrected to be close to those of sRGB or Adobe RGB, and then the color corrected data R _c , G _c , and B _c are output.

The color reproduction unit 310 may perform color correction through Equation 1.

In Equation 1, G _xx (x is R, G or B) denotes a color reproduction gain.

Luminance signal generation unit 330 then generates a luminance value (Y _i) on the basis of the color interpolator (200) the data (R _i, G _i, B _i) interpolation supplied from the generated luminance value (Y _i) To the color correction intensity generator 350.

Here, the luminance signal generator 330 may generate the luminance value Y _i through Equation 2.

Y _i = 0.299 × R _i + 0.587 × G _i + 0.114 × B _i

The color correction intensity generator 350 receives the luminance value Y _i from the luminance signal generator 330 and adaptively generates the color correction intensity value Strength according to the luminance value Y _i .

In detail, the color correction intensity generator 350 provides an area threshold, a maximum intensity value Str1, and a minimum intensity value Str2 from a control unit (not shown) of a system in which an image signal processing apparatus is mounted. The luminance value Y is divided into a first region and a second region according to an area threshold.

When the luminance value Y _i provided from the luminance signal generation unit 330 belongs to the first region, the color correction intensity generation unit 350 corresponds to the color correction intensity value corresponding to the luminance value Y _i according to Equation 3 below. (Strength) is adaptively generated between the maximum intensity value Str1 and the minimum intensity value Str2, and when the luminance value Y _i belongs to the second region, the minimum intensity value Str2 is defined as the color correction intensity value. Create (Strength) (ie Strength = Str2).

Strength = ((threshold-Y _i ) × Str1 + Y _i × Str2) / threshold)

The noise removing unit 370 is interpolated from the color interpolation unit 200 (R _i , G _i , B _i ), and the color corrected data from the color reproduction unit 310 (R _c , G _c , B _c ) After receiving the color correction intensity value (Strength) from the color correction intensity generation unit 350, the interpolated data (R _i , G _i , B _i ) and the color corrected data (R _c , G _c , Among the values between B _c ), a value corresponding to the color correction intensity value (Strength) is output as noise reduction data _Ro , G _o , and B _o .

The noise removing unit 370 may obtain noise removing data _Ro , G _o , and B _o by Equation 4.

R _o = ((Norm-Strength) × R _c + Strength × R _i ) / Norm

G _o = ((Norm-Strength) × G _c + Strength × G _i ) / Norm

B _o = ((Norm-Strength) × B _c + Strength × B _i ) / Norm

In Equation 4, Norm is used to normalize the noise reduction data _Ro , G _o , B _o to a predetermined value as a normalization variable. For example, the normalization variable can be 255.

FIG. 3 is a conceptual diagram for describing a function of the color correction intensity generation unit illustrated in FIG. 2.

Referring to FIG. 3, the color correction intensity generator 350 divides the luminance value Y into two regions of region 1 and region 2 based on the provided region threshold, and generates the luminance signal generator 330. In the case where the luminance value Y _i provided from) is included in the area 1 (that is, Y _i <threshold), the color correction intensity value Strength is converted into the maximum intensity value Str1 and the minimum intensity value Str2) is adaptively generated, and when the luminance value Y _i is included in the region 2 (that is, Y _i ≥ threshold), the minimum intensity value Str2 is generated as the color correction intensity value Strength.

That is, in the color correction process according to an embodiment of the present invention, in the dark part where the luminance value Y _i of the image is smaller than the region threshold (that is, region 1), the color correction intensity is increased and the luminance of the image is increased. In an area where the value Y _i is larger than the area threshold (that is, area 2), the color correction intensity is lowered to effectively remove color noise generated during the color correction process.

Further, when the luminance values in the image (Y _i) is smaller than the area threshold value (threshold), the luminance values between the maximum intensity value (Str1) and minimum strength value (Str2) is set on the basis of Equation 3 (Y _i) The corresponding color correction intensity value is adaptively determined.

The region threshold value, the maximum intensity value Str1, and the minimum intensity value Str2 determine the parameter values corresponding to the luminance of the image through an iterative experiment, and store them in the lookup table format. The controller of may be configured to provide the parameter value to the color correction intensity generator 350 according to the brightness of the image.

4 is a conceptual diagram for describing a function of the noise removing unit illustrated in FIG. 2.

Referring to FIG. 4, in the color correction process according to the exemplary embodiment of the present invention, as shown in FIG. 3, the color correction intensity value (Strength) is adaptively determined according to the luminance value of the image, and Equation 4 is used. By outputting the value corresponding to the color correction intensity (Strength) as noise removal data (R _o , G _o , B _o ) to remove the noise generated during the color correction process.

For example, when the color correction intensity (Strength) is '0' (that is, when no noise reduction is performed), the color corrected data R _c , G _c , and B _{c in} the color reproducing unit 310 are performed. By outputting to the noise canceling data (R _o , G _o , B _o ), noise canceling is not performed on color corrected data.

Alternatively, the color correction intensity value (Strength) is the "255" if the (that is, the maximum increased by the color correction intensity), the color interpolating the color interpolation in the 200 data (R _i, G _i, B _i) Output as noise reduction data (R _o , G _o , B _o ).

Alternatively, the color correction intensity value (Strength) is "0" and "255" that is the color interpolated data (R _i, G _i, B _i) values and the color correction data based on Equation 4. When between ( The data value corresponding to the color correction intensity value (Strength) between R _c , G _c , and B _c ) values is output as noise reduction data _Ro , G _o , and B _o .

5 is a flowchart illustrating a color correction process according to an embodiment of the present invention.

First, the image signal processing apparatus performs preprocessing such as shading correction caused by defect correction and / or short focal length of the lens with respect to Bayer image data provided from the image sensor. Perform (step 501).

Thereafter, the image signal processing apparatus divides each pixel component included in the pre-processed Bayer image data into R, G, and B components, and combines them to have each of the three channel components R, G, and B. to produce an interpolated color image data _{(R i, G i, B} i) ( step 503).

The image signal processing apparatus corrects color such that the spectral characteristics of the color interpolated data (R _i , G _i , B _i ) are close to the spectral characteristics of sRGB or Adobe RGB, and the color corrected data (R _c , G _c , B _c). ) Is output (step 505).

Further, the image signal processing apparatus generates by applying the equation (2) for the interpolated color data (R _i, G _i, B _i) the luminance value (Y _i) (step 507).

In addition, the image signal processing apparatus receives an area threshold value, a maximum intensity value Str1 and a minimum intensity value Str2 that are parameter values for removing noise from the system controller (step 509).

Thereafter, the image signal processing apparatus compares the luminance value Y _i generated in step 507 with the region threshold provided in step 509 (step 511), and the luminance value Y _i is the region boundary value. If smaller than (threshold) (i.e., the luminance value is included in the area 1), the color correction intensity value Strength is expressed between the maximum intensity value Str1 and the minimum intensity value Str2 using Equation 3. Generate adaptively (step 513).

In step 511, when the luminance value Y _i is greater than the region threshold (that is, when the luminance value is included in the region 2), the image signal processing apparatus may adjust the color correction intensity value (Strength). The minimum intensity value Str2 is set (step 515).

Then, the image signal processing apparatus includes phase of the values between the interpolated using equation (4) data (R _i, G _i, B _i) and the color-correction data (R _c, G _c, B _c) 513 or step 515 A value corresponding to the color correction intensity value (Strength) generated in step C is output as the noise removal data _Ro , G _o , and B _o (step 517).

6 is a view illustrating a color correction result of an image to which a color correction method is applied according to an embodiment of the present invention. FIG. 6A illustrates an image that is color interpolated by the color interpolator 200. b) shows a color corrected image according to a conventional color correction method. 6C shows the color corrected image according to the embodiment of the present invention.

As shown in FIG. 6, in the conventional color correction method, color correction is performed by applying collective color correction intensities to an entire image, so that undesired color noise occurs in the dark region 601.

However, in the color correction method according to the exemplary embodiment of the present invention, the luminance region of the image is divided into two regions according to the set region boundary value, and in the dark region, the luminance value obtained by calculating the color correction intensity value (Strength) ( Y _i ) to remove noise by adaptively applying and to remove noise by applying the minimum intensity value Str2 in bright areas, as shown in FIG. Noise can be removed efficiently.

Although described with reference to the embodiments above, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention as set forth in the claims below. Could be.

1 is a block diagram showing the configuration of a general image signal processing apparatus.

2 is a block diagram illustrating a configuration of an image signal processing apparatus according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram for describing a function of the color correction intensity generation unit illustrated in FIG. 2.

FIG. 4 is a conceptual diagram for describing a function of the color corrector shown in FIG. 2.

5 is a flowchart illustrating a color correction process according to an embodiment of the present invention.

6 illustrates a color correction result of an image to which a color correction method is applied according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: preprocessing unit 200: color interpolation unit

300: color correction unit 310: color reproduction unit

330: luminance signal generator 350: color correction intensity generator

370: color correction unit

Claims (12)

An image signal processing apparatus for performing color correction, A color interpolator for performing color interpolation on image data provided from an image sensor; And When color correction is performed on the data on which the color interpolation is performed and the luminance value is obtained based on the data on which the color interpolation is performed, when the obtained luminance value is smaller than a preset area boundary value, = ((threshold-Y _i ) × Str1 + Y _i × Str2) / threshold) (where Strength is the color correction intensity, threshold is the area boundary value, Str1 is the maximum intensity value, Str2 is the minimum intensity value, and Y _i is The color correction intensity, and when the obtained luminance value is larger than a preset area boundary value, the strength is equal to the strength value of Str2 (where Str2 represents the minimum intensity value). And a color correction unit for setting a color correction intensity and removing noise included in the color corrected data based on the set color correction intensity. The method of claim 1, wherein the color correction unit A color reproduction unit for performing color correction on the data on which the color interpolation has been performed; A luminance signal generator which obtains a luminance value based on the data on which color interpolation is performed; A color correction intensity generator configured to set a color correction intensity to a value corresponding to the luminance value among a value between a preset maximum intensity value and a preset minimum intensity value when the obtained luminance value is smaller than a preset area boundary value; And And a noise removing unit for removing noise included in color corrected data based on the set color correction intensity. The method of claim 2, wherein the color correction intensity generating unit, And the color correction intensity is set to the minimum intensity value when the obtained luminance value is equal to or greater than a preset area boundary value. delete The noise canceling unit of claim 2, The data value corresponding to the color correction intensity is obtained as noise reduction data from among values between the data value obtained by color correction provided from the color reproducing unit and the data value obtained by color interpolation provided from the color interpolation unit. The image signal processing device, characterized in that to remove the noise contained in the color-corrected data. The method of claim 5, wherein the noise removing unit, R _o = ((Norm-Strength) × R _c + Strength × R _i ) / Norm G _o = ((Norm-Strength) × G _c + Strength × G _i ) / Norm B _o = ((Norm-Strength) × B _c + Strength × B _i ) / Norm Where R _o , G _o and B _o are the noise reduction data, R _c , G _c and B _c are data values obtained by the color correction, and R _i , G _i and B _i are obtained by the color interpolation. And a noise value included in the color corrected data by using the acquired data value, Strength means color correction intensity, and Norm means normalization variable. In the color correction method of the image signal processing apparatus, Performing color interpolation on image data provided from the image sensor; Obtaining a luminance value based on the data on which the color interpolation has been performed; Performing color correction on the data on which the color interpolation has been performed; When the obtained luminance value is smaller than a predetermined region boundary value, the formula Strength = ((threshold-Y _i ) × Str1 + Y _i × Str2) / threshold) (where Strength is the color correction intensity and threshold is an area). The color correction intensity is set by a threshold value, Str1 is a maximum intensity value, Str2 is a minimum intensity value, and Y _i is the luminance value), and when the obtained luminance value is larger than a preset area boundary value, Setting the color correction intensity for = Str2, where Str2 means the minimum intensity value; And And removing noise included in the color corrected data based on the set color correction intensity. The method of claim 7, wherein the color correction method, And setting the color correction intensity to the minimum intensity value when the obtained luminance value is equal to or larger than a preset area boundary value. delete The method of claim 7, wherein the removing of the noise included in the color corrected data based on the set color correction intensity comprises: The noise included in the color corrected data is removed by acquiring a data value corresponding to the color correction intensity among the values between the data value obtained by the color correction and the data value obtained by the color interpolation as noise removal data. Color correction method characterized in that. The method of claim 10, wherein the removing of noise included in the color corrected data based on the set color correction intensity is performed by the following equation. R _o = ((Norm-Strength) × R _c + Strength × R _i ) / Norm G _o = ((Norm-Strength) × G _c + Strength × G _i ) / Norm B _o = ((Norm-Strength) × B _c + Strength ××× Norm Where R _o , G _o and B _o are the noise reduction data, R _c , G _c and B _c are data values obtained by the color correction, and R _i , G _i and B _i are obtained by the color interpolation. And a noise value included in the color corrected data by using the acquired data value, Strength means color correction intensity, and Norm means normalization variable. In the recording medium on which a program of instructions that can be executed by a digital processing apparatus that performs color correction of an image is tangibly implemented, and which records a program that can be read by the digital processing apparatus, Performing color interpolation on image data provided from the image sensor; Obtaining a luminance value based on the data on which the color interpolation has been performed; Performing color correction on the data on which the color interpolation has been performed; When the obtained luminance value is smaller than a predetermined region boundary value, the formula Strength = ((threshold-Y _i ) × Str1 + Y _i × Str2) / threshold) (where Strength is the color correction intensity and threshold is an area). The color correction intensity is set by a threshold value, Str1 is a maximum intensity value, Str2 is a minimum intensity value, and Y _i is the luminance value), and when the obtained luminance value is larger than a preset area boundary value, Setting the color correction intensity for = Str2, where Str2 means the minimum intensity value; And And recording a program for removing noise included in color corrected data based on the set color correction intensity.

Images