JP4055426B2 - Image processing apparatus, image processing program, and image processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image processing apparatus, and more particularly, to an image processing apparatus that processes a color image.
[0002]
[Prior art]
Some electronic cameras include an image processing unit that realizes the functions of an image processing apparatus by performing various types of image processing on generated color image data.
[0003]
FIG. 11 is a functional block diagram of an image processing unit in a conventional electronic camera.
According to the image processing unit 100 illustrated in FIG. 11, the input image data is subjected to white balance adjustment, interpolation and flattening processing, color correction processing, gamma processing, and edge enhancement processing via each unit. become.
In the white balance adjustment performed by the white balance adjustment unit 101, a white balance coefficient is used. Such a white balance coefficient is determined by the white balance coefficient calculation unit 102 according to color difference information and color temperature information.
[0004]
In addition, the interpolation and flattening processing unit 103, the color correction processing unit 104, and the gamma processing unit 105 have predetermined coefficients and gamma curves, and interpolation and flattening processing and color correction are performed using these coefficients and gamma curves. Processing and gamma processing are performed.
Further, the contour emphasis processing unit 106 performs contour emphasis processing using a predetermined contour emphasis coefficient or an edge emphasis coefficient corresponding to the emphasis degree set by the user.
[0005]
[Problems to be solved by the invention]
In such an image processing unit, when white balance adjustment is performed, a process of multiplying by a white balance coefficient is performed, so that noise included in input image data may be amplified. Also, in the color correction process, the gamma process, and the edge enhancement process, as with the white balance adjustment, the process of multiplying the coefficient is performed, so that noise may be amplified. In particular, the amplification of noise by the contour enhancement process is more significant than the amplification of noise by other image processes. Note that, during the interpolation and flattening processing, since averaging is performed in the course of the processing, noise may be offset and reduced.
[0006]
Moreover, in the conventional electronic camera, each image processing mentioned above was performed independently. That is, there is no correlation between the coefficients used in each process, so even if noise is amplified by white balance adjustment, the noise is further deteriorated by performing color correction processing and edge enhancement processing without considering this. There was something that would let me.
[0007]
Also, some conventional electronic cameras determine a color correction coefficient according to the color temperature of the subject, and select a gamma curve used for gamma processing according to the contrast of the subject. However, since the edge emphasis process is performed independently, noise may be deteriorated.
An object of the present invention is to provide an image processing apparatus, an image processing program, and an image processing method that can prevent noise from being deteriorated unnecessarily in the course of image processing.
[0008]
  The present inventionThe image processing deviceFor the input image data,At least white balance adjustmentprocessingWhenContourAn image processing apparatus that performs enhancement processing,image dataA light source characteristic acquisition unit that acquires a light source characteristic when the light source is generated, and the light source characteristic acquired by the light source characteristic acquisition unitColor temperature information calculated fromDepending on the white balance adjustmentprocessingThe white balance coefficient used when performingContourUsed for emphasis processingContourEmphasis processing coefficientIn consideration of the amplification of the noise of the image data by one of the white balance adjustment processing and the contour enhancement processing, the processing contents of the other processing are changed to each other.Coefficient determination means for determining in association with the white balance coefficient using the white balance coefficientprocessingDo the aboveContourUsing the enhancement factorContourImage processing means for performing enhancement processing;,It is provided with.
[0009]
  Preferably,The coefficient determination means includes theColor temperature informationAnd theColor temperature informationOther than the processing targetimage dataCharacteristics andBased on both, The white balance coefficient andAssociated contourEmphasis processing coefficientTheDecisionYou may do it.
  Also preferably,SaidColor temperature informationOther than the processing targetimage dataThe characteristics ofimage dataWith contrast characteristicsThere may be.
[0010]
  Also preferably,The image processing means adjusts the white balance.processingAfter doingContourIntermediate processing is performed before the enhancement processing, and the coefficient determining meansColor temperature informationDepending on the white balance coefficient and theContourThe enhancement processing coefficient is determined in association with the intermediate processing coefficient used when the intermediate processing is performed.You may do it.
[0011]
  Also preferably,The coefficient determination means includes theContourThe determination of the enhancement processing coefficientColor temperature informationUsing a lookup table according toYou can go.
  Preferably, the coefficient determination unit may determine the edge enhancement processing coefficient using a look-up table corresponding to the color temperature information and the contrast characteristics.
  Preferably, the intermediate process is a flattening process, and the intermediate process coefficient may be a flattening process coefficient.
  Preferably, the coefficient determining means may determine the flattening processing coefficient using a look-up table corresponding to the color temperature information and the contrast characteristics of the image data.
  The present inventionThe program ofFor the input image data,At least white balance adjustmentprocessingWhenContourWith emphasis processingimage dataA program for realizing, with a computer, control over an image processing apparatus including a light source characteristic acquisition unit that acquires a light source characteristic when a light source is generated, the light source characteristic acquired by the light source characteristic acquisition unitColor temperature information calculated fromDepending on the white balance adjustmentprocessingThe white balance coefficient used when performingContourUsed for emphasis processingContourEmphasis processing coefficientIn consideration of the amplification of the noise of the image data by one of the white balance adjustment processing and the contour enhancement processing, the processing contents of the other processing are changed to each other.Coefficient determination procedure to determine in association with the white balance adjustment using the white balance coefficientprocessingDo the aboveContourUsing the enhancement factorContourImage processing procedure for emphasis processing,Is realized by a computer.
[0012]
  The present inventionThe image processing method ofimage dataA light source characteristic acquisition step of acquiring the characteristics of the light source when the light source is generated, and the light source characteristic acquired by the light source characteristic acquisition stepColor temperature information calculated fromDepending on the white balance adjustmentprocessingWhite balance coefficient used when performingContourUsed for emphasis processingContourEmphasis processing coefficientIn consideration of the amplification of the noise of the image data by one of the white balance adjustment processing and the contour enhancement processing, the processing contents of the other processing are changed to each other.A coefficient determination step for determining in association with the white balance adjustment using the white balance coefficientprocessingDo the aboveContourUsing the enhancement factorContourAn image processing step for performing enhancement processing;,It is provided with.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the following embodiments, description will be made using an electronic camera having a function of image processing performed by the image processing apparatus of the present invention.
[0014]
<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a schematic configuration of the electronic camera according to the first embodiment.
In FIG. 1, an electronic camera 1 includes a photographing lens 10, an image sensor 11, an A / D converter 12, an image processing unit 13, a compression unit 15, a recording unit 16, and a division sensor (not shown).
[0015]
Image data obtained by the image sensor 11 is converted into a digital signal by the A / D converter 12, and the image processing unit 13 performs image processing based on information (light source characteristics, image contrast, etc.) obtained by the division sensor. Is given. When the image processing is completed, the data is output to the compression unit 15 and the recording unit 16.
Here, the image processing performed in the present embodiment is white balance adjustment, interpolation and flattening processing, color correction processing, gamma processing, and contour enhancement processing. In addition, a signal indicating photometric information output by the split sensor is input to a color temperature calculation unit 17 and a contrast calculation unit 18 in the image processing unit 13 described later. Such a split sensor may be an external light type, or may be an internal light type that branches and takes in a part of the light beam incident from the photographing lens 10.
[0016]
In the electronic camera 1, a program indicating the operation content of each unit is recorded in advance. The program may be recorded on a recording medium or downloaded as a transmission wave via the Internet.
FIG. 2 is a functional block diagram of the image processing unit 13 in the electronic camera 1 of the first embodiment.
[0017]
In FIG. 2, the image processing unit 13 includes a white balance adjustment unit 20, an interpolation and flattening processing unit 22, a color correction processing unit 24, a gamma processing unit 26, and an outline enhancement processing unit 28. The image processing unit 13 also includes a color temperature calculation unit 17, a contrast calculation unit 18, a white balance coefficient calculation unit 19, a flatness for determining coefficients (including a gamma curve) used for image processing in these units. A conversion coefficient calculation unit 21, a color correction coefficient calculation unit 23, a gamma curve selection unit 25, and an edge enhancement coefficient calculation unit 27 are provided.
[0018]
Hereinafter, the operation of the image processing unit 13 will be described. A specific method of image processing in the image processing unit 13 is the same as that of a known technique. Therefore, in the following, only the method for determining the coefficients used for each image process will be described, and the other description will be omitted.
<Determination of white balance coefficient>
The white balance coefficient used for white balance adjustment is determined by the white balance coefficient calculator 19 according to the color temperature. The color temperature is calculated by the color temperature calculation unit 17 based on information obtained by the division sensor. The white balance coefficient calculation unit 19 outputs a signal indicating the calculated white balance coefficient to the white balance adjustment unit 20.
[0019]
<Determination of coefficients used for interpolation>
The coefficient used for the interpolation is determined in advance according to the characteristics of the image sensor 11. <Determination of flattening coefficient>
The flattening coefficient used in the flattening process is a value representative of the contrast amount of the subject calculated by the contrast calculation unit 18 based on the color temperature calculated by the color temperature calculation unit 17 and information obtained by the division sensor (hereinafter, “ Is determined by the flattening coefficient calculator 21 in accordance with “contrast value”. The contrast calculation unit 18 divides the information obtained by the division sensor into small regions, calculates a value obtained by multiplying the luminance difference between the bright part and the dark part by a certain normalization coefficient, and sets it as a contrast value. In the present embodiment, the contrast value is represented by 1 to 7, and the larger the contrast value, the larger the contrast, that is, the larger the luminance difference between the bright part and the dark part of the object scene.
[0020]
The flattening coefficient calculator 21 calculates a flattening coefficient according to the color temperature and the contrast value. Specifically, first, a flattening degree is determined using a look-up table (hereinafter referred to as “LUT”) as shown in FIG.
FIG. 3 is an example of the LUT used when determining the flattening degree.
The horizontal axis in FIG. 3 indicates the color temperature, the vertical axis indicates the contrast value, and the smaller the contrast value, the smaller the contrast of the subject, and the larger the contrast value, the greater the contrast of the subject. The numerical value in the LUT indicates the flattening degree. The smaller the numerical value, the smaller the flattening degree, and the larger the numerical value, the larger the flattening degree. Using the LUT, the flattening coefficient calculation unit 21 determines a flattening degree according to the color temperature and the contrast value, and calculates a flattening coefficient that realizes the determined flattening degree. Then, the flattening coefficient calculator 21 outputs a signal indicating the calculated flattening coefficient to the interpolation and flattening processor 22.
[0021]
Note that the LUT shown in FIG. 3 is created in advance based on the following concept and is recorded in the flattening coefficient calculation unit 21.
FIG. 4 is a conceptual diagram for explaining the LUT shown in FIG.
As shown in FIG. 4, the degree of flattening is set so that the color temperature is 4000K (the color temperature of sunlight, the color temperature that is the standard of WB), the smaller the distance is, the larger the distance is from the center. . Further, the flattening degree is set to be smaller as the contrast of the subject is larger, and is set to be larger as the contrast of the subject is smaller.
[0022]
Therefore, when noise is amplified by white balance adjustment because the color temperature is away from 4000 K, the level of flattening can be increased to reduce the noise.
<Determination of color correction coefficient>
The color correction coefficient used in the color correction process is calculated by the color correction coefficient calculation unit 23 based on the color temperature calculated by the color temperature calculation unit 17. The color correction coefficient calculation unit 23 outputs a signal indicating the calculated color correction coefficient to the color correction processing unit 24. Such a determination method can be similarly performed using the method disclosed in US Pat. No. 5,805,213, and detailed description thereof will be omitted.
[0023]
<Determination of gamma curve>
Selection of a gamma curve used for gamma processing is performed by the gamma curve selection unit 25. That is, the gamma curve selection unit 25 uses which gamma curve among a plurality of gamma curves recorded in advance in the gamma processing unit 26 according to the contrast information including the contrast value calculated by the contrast calculation unit 18. And a signal indicating the content of the determination is output to the gamma processing unit 26. Such a determination method can be similarly performed using the method disclosed in Japanese Patent Laid-Open No. 2001-54014, and thus detailed description thereof is omitted.
[0024]
<Determination of edge enhancement processing coefficient>
The contour enhancement coefficient used for the contour enhancement processing is determined by the contour enhancement coefficient calculation unit 27 according to the color temperature and the contrast value, similarly to the flattening processing coefficient.
The contour enhancement coefficient calculation unit 27 calculates a contour enhancement coefficient according to the color temperature and the contrast value. Specifically, first, the degree of edge enhancement is determined using an LUT as shown in FIG.
[0025]
FIG. 5 is an example of an LUT used when determining the degree of edge enhancement.
The horizontal axis in FIG. 5 represents the color temperature, the vertical axis represents the contrast value, and the smaller the contrast value, the smaller the contrast of the subject, and the larger the contrast value, the greater the contrast of the subject. The numerical value in the LUT indicates the degree of edge enhancement. The smaller the value, the smaller the edge enhancement degree. The larger the number, the higher the edge enhancement degree. The edge enhancement coefficient calculation unit 27 determines the edge enhancement degree according to the color temperature and the contrast value using such an LUT, and calculates the edge enhancement coefficient that realizes the determined edge enhancement degree. Then, the contour enhancement coefficient calculation unit 27 outputs a signal indicating the calculated contour enhancement coefficient to the contour enhancement processing unit 28.
[0026]
Note that the LUT shown in FIG. 5 is created in advance based on the following concept and is recorded in the contour enhancement coefficient calculation unit 27.
FIG. 6 is a conceptual diagram for explaining the LUT shown in FIG.
As shown in FIG. 6, the degree of contour emphasis is set so that the color temperature is 4000 K (the color temperature of sunlight, the color temperature that is the standard of WB), and the larger the value is, the smaller the distance from the center is. . Also, the degree of contour enhancement is set larger as the contrast of the subject is larger, and is set smaller as the contrast of the subject is smaller.
[0027]
Therefore, when noise is amplified by white balance adjustment because the color temperature is away from 4000 K, it is possible to prevent the deterioration of noise by determining the degree of edge enhancement to be small. Further, when the noise is not amplified by the white balance adjustment because the color temperature is about 4000K, it is possible to determine the degree of outline enhancement to obtain a clearer image.
[0028]
As described above, according to the first embodiment, the coefficients used when performing the white balance adjustment, interpolation and flattening processing, color correction processing, gamma processing, and edge enhancement processing are obtained by the division sensor. Each image processing is performed based on the determined information. Therefore, it is possible to prevent the noise from being deteriorated unnecessarily during the image processing.
[0029]
In particular, even when noise is amplified by white balance adjustment, noise can be reduced by increasing the level of flattening, and noise can be eliminated by reducing the degree of contour enhancement. It can be prevented from getting worse.
<< Second Embodiment >>
The second embodiment of the present invention will be described below with reference to the drawings. In the second embodiment, only parts different from the first embodiment will be described, and description of parts common to the first embodiment will be omitted.
[0030]
The electronic camera 2 of the second embodiment includes an image processing unit 29 instead of the image processing unit 13 of the electronic camera 1 of the first embodiment, and includes a color temperature sensor (not shown) instead of the division sensor. Since other configurations are the same as those in the first embodiment, description and illustration are omitted, and hereinafter, description will be made using the same reference numerals as those in FIG.
In the image processing unit 29 of the electronic camera 2, each image processing is performed based on information (such as light source characteristics) obtained by the color temperature sensor. In the electronic camera 2, similarly to the electronic camera 1, a program indicating the operation content of each unit is recorded in advance.
[0031]
FIG. 7 is a functional block diagram of the image processing unit 29 in the electronic camera 2 of the second embodiment.
In FIG. 7, the image processing unit 29 omits the contrast calculation unit 18 and the gamma curve selection unit 25 of the image processing unit 13 of the first embodiment, and a color temperature calculation unit 31 instead of the color temperature calculation unit 17. A flattening coefficient calculation unit 32 is provided instead of the flattening coefficient calculation unit 21, and an outline enhancement coefficient calculation unit 33 is provided instead of the outline enhancement coefficient calculation unit 27. The other parts are the same as those in the first embodiment, and are therefore given the same reference numerals as in the first embodiment.
[0032]
Hereinafter, the operation of the image processing unit 29 will be described. A specific method of image processing in the image processing unit 29 is the same as that of a known technique. Therefore, in the following, as in the first embodiment, only the method for determining the coefficients used for each image process will be described, and the other description will be omitted.
<Determination of white balance coefficient>
The white balance coefficient used for white balance adjustment is determined according to the color temperature, as in the first embodiment. The color temperature is calculated by the color temperature calculation unit 31 based on information obtained by the color temperature sensor. The white balance coefficient calculation unit 19 outputs a signal indicating the calculated white balance coefficient to the white balance adjustment unit 20.
[0033]
<Determination of coefficients used for interpolation>
The coefficient used for the interpolation is determined in advance according to the characteristics of the image sensor 11 as in the first embodiment.
<Determination of flattening coefficient>
The flattening coefficient used in the flattening process is determined by the flattening coefficient calculating unit 32 according to the color temperature calculated by the color temperature calculating unit 31 based on information obtained by the color temperature sensor.
[0034]
The flattening coefficient calculator 32 determines a flattening coefficient using an LUT as shown in FIG. 8 recorded in the flattening coefficient calculator 32 in advance, and interpolates and flattens a signal indicating the determined flattening coefficient. To the processing unit 22.
The LUT shown in FIG. 8 has a flattening coefficient centered on the color temperature of 4000K, and a flattening coefficient that decreases the flattening degree as it is closer to the center, and a flattening coefficient that increases the flattening degree as the distance from the center increases. It has been established.
[0035]
Therefore, when noise is amplified by white balance adjustment because the color temperature is away from 4000 K, the level of flattening can be increased to reduce the noise.
<Determination of color correction coefficient>
The color correction coefficient used for the color correction process is determined by the color correction coefficient calculation unit 23 based on the color temperature calculated by the color temperature calculation unit 31 as in the first embodiment.
[0036]
<Determination of gamma curve>
As the gamma curve used for the gamma processing, one gamma curve is set in the gamma processing unit 26 in advance.
<Determination of edge enhancement processing coefficient>
The contour enhancement coefficient used for the contour enhancement processing is determined by the contour enhancement coefficient calculation unit 33 according to the color temperature calculated by the color temperature calculation unit 31 based on information obtained by the color temperature sensor.
[0037]
The contour enhancement coefficient calculation unit 33 determines using the LUT as shown in FIG. 9 recorded in the contour enhancement coefficient calculation unit 33 in advance, and outputs a signal indicating the determined contour enhancement coefficient to the contour enhancement processing unit 28. To do.
The LUT shown in FIG. 9 has a contour enhancement coefficient centered on the color temperature of 4000K, and a contour enhancement coefficient that increases the contour enhancement degree as it is closer to the center. It has been established.
[0038]
Therefore, when noise is amplified by white balance adjustment because the color temperature is away from 4000 K, it is possible to prevent the deterioration of noise by determining the degree of edge enhancement to be small. Further, when the noise is not amplified by the white balance adjustment because the color temperature is about 4000K, it is possible to determine the degree of outline enhancement to obtain a clearer image.
[0039]
As described above, according to the second embodiment, the coefficients used when performing the white balance adjustment, the flattening process, the color correction process, and the edge enhancement process are the information obtained by the color temperature sensor. Each image processing is performed based on the determination. Therefore, it is possible to prevent the noise from being deteriorated unnecessarily during the image processing.
[0040]
In particular, even when noise is amplified by white balance adjustment, noise can be reduced by increasing the level of flattening, and noise can be eliminated by reducing the degree of contour enhancement. It can be prevented from getting worse.
<< Third Embodiment >>
The third embodiment of the present invention will be described below with reference to the drawings. In the third embodiment, like the second embodiment, only the parts different from the first embodiment will be described, and the description of the parts common to the first embodiment will be omitted.
[0041]
The electronic camera 3 of the third embodiment includes an image processing unit 34 instead of the image processing unit 13 of the electronic camera 1 of the first embodiment, and includes a light source selection unit (not shown) instead of the split sensor. Since other configurations are the same as those in the first embodiment, description and illustration are omitted, and hereinafter, description will be made using the same reference numerals as those in FIG.
Here, the light source selection unit is an operation such as a button for selecting a light source illuminating an object, such as sunlight, a light bulb, a fluorescent light, a cloudy sky, or a flash device, or a menu displayed on a monitor, by a user operation. Part. The image processing unit 34 of the electronic camera 3 performs image processing based on information indicating the type of light source selected by the light source selection unit.
[0042]
In the electronic camera 3, similarly to the electronic camera 1, a program indicating the operation content of each unit is recorded in advance.
FIG. 10 is a functional block diagram of the image processing unit 34 in the electronic camera 3 according to the third embodiment.
In FIG. 10, the flattening coefficient calculation unit 21, the color correction coefficient calculation unit 23, and the gamma curve selection unit 25 of the image processing unit 13 of the first embodiment are omitted from the image processing unit 34, and the color temperature calculation unit 17. Instead, a color temperature calculation unit 36 is provided, and an edge enhancement coefficient calculation unit 37 is provided instead of the edge enhancement coefficient calculation unit 27. The other parts are the same as those in the first embodiment, and are therefore given the same reference numerals as in the first embodiment.
[0043]
Hereinafter, the operation of the image processing unit 34 will be described, but a specific method of image processing in the image processing unit 34 is the same as that of a known technique. Therefore, in the following, as in the first embodiment and the second embodiment, only the method for determining the coefficients used for each image process will be described, and the other description will be omitted.
<Determination of white balance coefficient>
The white balance coefficient used for white balance adjustment is calculated according to the color temperature, as in the first embodiment. The color temperature is calculated by the color temperature calculator 36 according to the light source selected by the light source selector. The white balance coefficient calculation unit 19 outputs a signal indicating the calculated white balance coefficient to the white balance adjustment unit 20.
[0044]
<Determination of coefficients used for interpolation>
Similar to the first and second embodiments, the coefficients used for the interpolation are determined in advance according to the characteristics of the image sensor 11.
<Determination of flattening coefficient>
The flattening coefficient used for the flattening process is determined in advance in the interpolation and flattening processing unit 22.
[0045]
<Determination of color correction coefficient>
The color correction coefficient used for the color correction process is determined in advance in the color correction processing unit 24.
<Determination of gamma curve>
As for the gamma curve used for the gamma processing, one gamma curve is determined in advance in the gamma processing unit 26 as in the second embodiment.
[0046]
<Determination of edge enhancement processing coefficient>
The contour enhancement coefficient used for the contour enhancement processing is determined by the contour enhancement coefficient calculation unit according to the color temperature calculated by the color temperature calculation unit 36.
Similar to the second embodiment, the contour enhancement coefficient calculation unit 37 uses the same LUT as that shown in FIG. 9 recorded in advance in the contour enhancement coefficient calculation unit 37 according to the color temperature. The coefficient is determined, and a signal indicating the determined edge enhancement coefficient is output to the edge enhancement processing unit 28.
[0047]
By determining the contour enhancement degree in this way, the same effect as in the second embodiment can be obtained.
As described above, according to the third embodiment, the contour enhancement coefficient is determined based on the information obtained by the light source selection unit to perform the contour enhancement processing. Therefore, it is possible to prevent the noise from being deteriorated unnecessarily during the image processing.
[0048]
In particular, when noise is amplified by white balance adjustment, it is possible to prevent the noise from being deteriorated unnecessarily by reducing the degree of contour enhancement.
In the third embodiment, the example in which the flattening coefficient and the color correction coefficient are determined in advance is shown. However, according to the color temperature calculated by the color temperature calculation unit 36, the second embodiment has been described. It may be calculated by such a method. In this case, a flattening coefficient calculation unit and a color correction coefficient calculation unit are newly provided, and an LUT similar to that shown in FIG. 8 may be recorded in advance in the flattening coefficient calculation unit.
[0049]
In each of the above embodiments, an example is shown in which the coefficients used for each image processing are calculated according to information obtained using a division sensor, a color temperature sensor, a light source selection unit, and the like. The coefficient used for each image processing may be calculated according to the information based on the image data.
In each of the above embodiments, the example in which white balance adjustment is given priority and other image processing is performed in consideration of noise amplification by white balance adjustment has been described, but priority may be given to other image processing. good. For example, the content of white balance adjustment may be changed by giving priority to the contour enhancement processing and considering noise amplification by the contour enhancement processing. Which image processing is prioritized may be determined in advance or may be selectable by a user operation.
[0050]
In each of the above embodiments, the coefficient used for each image processing is calculated according to the color temperature and contrast. However, the coefficient may be calculated by combining the ISO sensitivity.
Further, in each of the above embodiments, the color temperature and the contrast value are automatically calculated by the color temperature calculation unit and the contrast calculation unit. However, the user sets the color temperature, the contrast value, and the ISO sensitivity. You may do it.
[0051]
【The invention's effect】
As described above, according to the present invention, various image processing can be performed by determining the coefficient used for each image processing according to the light source characteristics (color temperature, etc.) when the image to be processed is generated. In doing so, it is possible to prevent noise from deteriorating unnecessarily.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a schematic configuration of an electronic camera according to a first embodiment.
FIG. 2 is a functional block diagram of an image processing unit in the electronic camera of the first embodiment.
FIG. 3 is an example of an LUT used when determining a flattening degree.
FIG. 4 is a conceptual diagram for explaining an LUT.
FIG. 5 is an example of an LUT used when determining the degree of edge enhancement.
FIG. 6 is a conceptual diagram for explaining an LUT.
FIG. 7 is a functional block diagram of an image processing unit in the electronic camera of the second embodiment.
FIG. 8 is an example of an LUT used when determining the degree of flattening.
FIG. 9 is an example of an LUT used when determining the degree of edge enhancement.
FIG. 10 is a functional block diagram of an image processing unit in an electronic camera according to a third embodiment.
FIG. 11 is a functional block diagram of an image processing unit in a conventional electronic camera.
[Explanation of symbols]
1,2,3 electronic camera
10 Shooting lens
11 Image sensor
12 A / D converter
13, 29, 34, 100 Image processing unit
15 Compression unit
16 Recording section
17, 31, 36 Color temperature calculator
18 Contrast calculator
19,102 White balance coefficient calculator
20, 101 White balance adjustment section
21, 32 Flattening coefficient calculator
22,103 Interpolation and flattening processing unit
23 Color correction coefficient calculator
24,104 color correction processing unit
25 Gamma curve selector
26,105 Gamma processing unit
27, 33, 37 Outline enhancement coefficient calculation unit
28, 106 Outline enhancement processing unit

Claims (10)

An image processing apparatus that performs at least white balance adjustment processing and contour enhancement processing on input image data ,
Light source characteristic acquisition means for acquiring light source characteristics when image data to be processed is generated;
In accordance with the color temperature information calculated from the obtained light source characteristics by the light source characteristic acquisition means, and white balance coefficients used in performing the white balance adjustment processing, edge enhancement processing used when performing the edge enhancement processing A coefficient that is determined in association with each other so as to change the processing content of the other process in consideration of the noise amplification of the image data by one of the white balance adjustment process and the edge enhancement process A determination means;
It performs the white balance adjustment processing using the white balance coefficient, and an image processing means for performing the edge enhancement processing using the edge enhancement processing coefficients,
An image processing apparatus comprising: The image processing apparatus according to claim 1.
Said coefficient determining means, and the color temperature information, based on both the characteristics of the image data of the processing target other than the color temperature information, determining said edge enhancement coefficients associated with the white balance coefficient A featured image processing apparatus. The image processing apparatus according to claim 2,
The image processing apparatus, wherein the characteristic of the image data to be processed other than the color temperature information is a contrast characteristic of the image data to be processed. The image processing apparatus according to claim 1.
The image processing means performs an intermediate process between the white balance adjustment process and the edge enhancement process.
The coefficient determination means determines the white balance coefficient, the edge enhancement processing coefficient, and the intermediate processing coefficient used when the intermediate processing is performed in association with each other according to the color temperature information. Image processing device. The image processing apparatus according to claim 1.
The image processing apparatus characterized in that the coefficient determining means determines the edge enhancement processing coefficient using a look-up table corresponding to the color temperature information . The image processing apparatus according to claim 3.
The coefficient determining unit determines the edge enhancement processing coefficient using a look-up table corresponding to the color temperature information and the contrast characteristics.
An image processing apparatus. The image processing apparatus according to claim 4.
The intermediate process is a flattening process, and the intermediate process coefficient is a flattening process coefficient.
An image processing apparatus. The image processing apparatus according to claim 7.
The coefficient determining means determines the flattening processing coefficient using a look-up table corresponding to the color temperature information and the contrast characteristics of the image data.
An image processing apparatus. Control for an image processing apparatus including a light source characteristic acquisition unit that performs at least white balance adjustment processing and contour enhancement processing on input image data, and acquires light source characteristics when image data to be processed is generated A program for realizing the above on a computer,
In accordance with the color temperature information calculated from the obtained light source characteristics by the light source characteristic acquisition means, and white balance coefficients used in performing the white balance adjustment processing, edge enhancement processing used when performing the edge enhancement processing A coefficient that is determined in association with each other so as to change the processing content of the other process in consideration of the noise amplification of the image data by one of the white balance adjustment process and the edge enhancement process Decision procedure;
Performs the white balance adjustment processing using the white balance coefficient, and an image processing procedure for performing the edge enhancement processing using the edge enhancement processing coefficients,
A program characterized by being realized by a computer. A light source characteristic acquisition step of acquiring the characteristics of the light source when the image data to be processed is generated;
In accordance with the color temperature information calculated from the light source characteristics acquired by the light source characteristic acquisition step, the white balance coefficients used in performing the white balance adjustment process, and edge enhancement processing coefficients used in performing the edge enhancement processing A coefficient determination step for determining in association with each other so as to change the processing content of the other processing in consideration of the amplification of noise of the image data by one of the white balance adjustment processing and the edge enhancement processing ; ,
Wherein performs the white balance adjustment process using the white balance coefficient, and an image processing step of performing the edge enhancement processing using the edge enhancement processing coefficients,
An image processing method comprising:

Images