JP6035958B2 - Image processing apparatus, image display apparatus, and image processing method - Google Patents

Description

  The present invention relates to an image processing apparatus, an image display apparatus, and an image processing method for displaying an image in a color gamut different from the color gamut of an input image signal.

  In a conventional image display apparatus, the color reproduction area that can be expressed is various, and may differ from the color gamut of the broadcasting system defined by the standard or the like. For example, in an image display device such as a liquid crystal television, a device that uses a semiconductor light source such as an LED (Light Emitting Diode) as a light source is generally known. In an image display device using such a semiconductor light source, a color reproduction gamut wider than a color gamut that can be displayed by a video signal of a high-definition television broadcast called HDTV (High Definition Television) may be realized.

  When there is an image display device that displays an image in a color gamut different from the color gamut of the input image signal, image processing for mapping the color space of the input image signal to a color space suitable for the image display device can be performed. Generally known. Here, mapping is to convert each pixel of the input image signal into a color space of the input image signal and a color space that can be expressed by the image display device.

  At this time, there is a problem that the object color with high saturation is glaring and looks unnatural by mapping. Some conventional display devices that solve such problems include a luminance adjustment unit. If the boundary between the object color and the emission color included in the input video signal is the target line, and the boundary for determining the object color and the emission color included in the output video signal is the determination line, the brightness adjustment unit When the luminance of the pixel is lower than the determination line, the luminance of the pixel is adjusted to be lower than the target line based on the target line and the determination line. As described above, when an input video signal corresponding to a predetermined color space is mapped to a color space having a wider color gamut than the predetermined color space, the conventional display device adjusts the luminance (for example, Patent Document 1). reference).

Japanese Patent Laying-Open No. 2011-124708 (page 6-10, FIG. 1)

  However, the prior art as described above is a method of comparing the luminance of a pixel with a discrimination line. Since this method does not determine whether the signal level of the color component that is the color signal or the color difference signal is saturated, the color space cannot be correctly converted when the color component is saturated.

  The present invention has been made to solve the above-described problems, and a first object thereof is to correctly convert a color space even when a color component is saturated in an input image.

In the image processing apparatus according to the present invention, a saturation determination unit that outputs a result of determining whether a color-related signal is saturated for each pixel of the input image as a saturation determination result, and calculates a hue for each pixel A color distribution analysis unit that outputs the result as a hue signal; and if the saturation determination result indicates that the color component is saturated for each pixel, the color component is corrected based on the hue signal and the color component is corrected. A color signal correction unit that outputs a correction signal; and a color space conversion unit that generates an output image by converting the color component correction signal into a different color space, and each pixel of the input image includes a luminance component and a color difference component The saturation determination unit outputs a result of determining whether or not the color difference component is saturated as a saturation determination result, and the color distribution analysis unit is configured to output the input image. The hue calculated using the saturation determination result and the color difference component for a pixel is output as the hue signal, and the color signal correction unit is configured to saturate the color difference component of the saturation determination result for each pixel. If it shows that a shall be outputted as the color component correction signal by correcting the color difference component on the basis of the hue signal.

  The present invention determines whether or not a signal related to color is saturated for each pixel of the input image, and calculates a hue for each pixel when the signal related to color is saturated for each pixel of the input image and By converting the color space after correcting it using a signal related to the color of each pixel, the color space can be correctly converted even if the color component is saturated in the input image.

It is a figure which shows the image processing apparatus which shows Embodiment 1 of this invention. It is a flowchart which shows the image processing method which shows Embodiment 1 of this invention. It is a figure which shows the image processing apparatus which shows Embodiment 2 of this invention. It is a flowchart which shows the image processing method which shows Embodiment 2 of this invention. It is a figure which shows the image processing apparatus which shows Embodiment 3 of this invention. It is a flowchart which shows the image processing method which shows Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a diagram showing an image processing apparatus according to Embodiment 1 for carrying out the present invention. In FIG. 1, 101 is a saturation determination unit, 102 is a color distribution analysis unit, 103 is a color signal correction unit, and 104 is a color space conversion unit. D0 is an input image signal, and D0 shown in the present embodiment is, for example, an RGB format signal. D104 is an output image of the color space conversion unit 104, and is connected to a subsequent circuit or device. If the image processing apparatus is provided in the image display apparatus, D104 is connected to a display unit (not shown) provided in the image display apparatus, and the display unit displays the output image D104.

  The saturation determination unit 101 outputs a result of determining whether or not a color-related signal is saturated for each pixel of the input image D0 as a saturation determination result D101. Here, since D0 is an RGB format signal, more specifically, it is determined whether or not at least one of the R component, the G component, and the B component is saturated, and the determination result is output as the saturation determination result D101.

  The determination method here is, for example, that the absolute value of each of the R component, the G component, and the B component is determined to be saturated for the corresponding color component if the value is equal to or greater than a predetermined threshold value. What is necessary is just to determine that it is not saturated about color components other than. At this time, information indicating which color component is saturated may be included in the saturation determination result D101.

  The color distribution analysis unit 102 outputs the result of calculating the hue for each pixel of the input image D0 as the hue signal D102. Specifically, the color distribution is analyzed in the vicinity of each pixel of the input image D0. Based on the analysis result, the hue calculated for each pixel of the input image D0 is output as the hue signal D102.

  At this time, as a target of a region in the vicinity of each pixel, a pixel whose color components (R component, G component, and B component) are not saturated using the saturation determination result D101 may be the target. In this way, the hue is calculated from the pixels in the vicinity of the pixel whose color components (R component, G component, and B component) are not saturated, and the average value or the intermediate value is set as the hue of the pixel. Thus, it is possible to obtain a hue excluding pixels in which color components are saturated.

  Next, a method for calculating the hue from the RGB format signal will be described. The conversion from the RGB format to the YCbCr format is expressed by, for example, the first formula.

また、色相θとＣｂ、Ｃｒとの関係は第２式のように表される。

Further, the relationship between the hue θ and Cb and Cr is expressed by the second equation.

このようにして各画素の色相を求めることは可能であり、ある画素位置の近傍の画素にあたる色相からその平均値や中間値をその画素位置の色相とする。

In this way, the hue of each pixel can be obtained, and the average value or the intermediate value is set as the hue at the pixel position from the hues corresponding to the pixels near the pixel position.

  The color signal correction unit 103 outputs a color component correction signal D103 obtained by performing color component correction on a pixel whose color component is saturated based on the saturation determination result D101 and the hue signal D102 for each pixel of the input image D0. . Specifically, when the saturation determination result D101 indicates that the color component is not saturated for each pixel of the input image D0, the input image D0 is output as it is as the color component correction signal D103, and the color component is saturated. If the color component is indicated, the color component is corrected from the input image D0 of the pixel and the hue signal D102, and is output as a color component correction signal D103.

  Next, a correction method for correcting a color component from the input image D0 and the hue signal D102 of the pixel will be described. For example, the case where the R component at a certain pixel position is saturated will be described. In this case, the color component of the saturation determination result D101 at this pixel position is saturated. In order to correct the color component at this pixel position, the color signal correction unit 103 first replaces the saturated R component value with an unknown variable x. In this case, formulas for obtaining Cb and Cr are derived from the first formula to the third formula.

一方、この画素位置の色相θは色分布分析部１０２によって求まっているため、第２式から第４式の方程式が得られる。

On the other hand, since the hue θ at the pixel position is obtained by the color distribution analysis unit 102, the equations of the second equation to the fourth equation are obtained.

この画素位置のＧ成分およびＢ成分は飽和していないので第４式にＧ成分およびＢ成分の値を入れてこの方程式を解けば未知の変数ｘを求めることができる。

Since the G component and the B component at this pixel position are not saturated, the unknown variable x can be obtained by entering the values of the G component and the B component into the fourth equation and solving this equation.

  The color space conversion unit 104 converts the color component correction signal D103 into a different color space and generates an output image D104. Here, the different color space is a color space that is different from the color space of the input image, and is convenient for a later circuit (not shown). The subsequent circuit is, for example, a display unit. In this case, a convenient color space refers to a color space corresponding to a color reproduction region of the display unit. If the subsequent stage of the color space conversion unit is another image processing apparatus, it indicates a color space that is convenient for the image processing apparatus. If the color space format convenient for the subsequent circuit is other than the RGB format (for example, XYZ format, L * a * b * format, etc.), conversion suitable for the format is performed.

  FIG. 2 is a flowchart showing the processing procedure of the image processing method according to the first embodiment of the present invention. The illustrated image processing method includes a saturation determination step ST101, a color distribution analysis step ST102, a color signal correction step ST103, and a color space conversion step ST104. The saturation determination step ST101 is the same as the saturation determination hand unit 101, the color distribution analysis step ST102 is the hue calculation unit 2, the color signal correction step ST103 is the color signal correction unit 103, and the color space conversion step ST104 is the same as the color space conversion unit 104. To work.

  In the image processing method according to the present embodiment, first, in the saturation determination step ST101, it is determined whether or not a color-related signal is saturated for each pixel of the input image D0. Next, a hue is calculated for each pixel of the input image D0 in the color distribution analysis step ST102. At this time, if a pixel related to the color is saturated in the pixel in the vicinity when calculating the hue according to the determination result of the saturation determination step ST101, the pixel may be excluded from the target pixel for calculating the hue. Next, if it is determined in the color signal correction step ST103 that the signal related to the color is saturated by the determination result in the saturation determination step ST101, the hue calculated in the color distribution analysis step ST102 and the original input image D0 A corrected color component signal is generated. Next, in the color space conversion step ST104, the output image D104 is generated by converting into a different color space using the result of the color signal correction step ST103.

  As described above, the image processing apparatus and the image processing method according to the present embodiment determine whether or not the color-related signal is saturated for each pixel of the input image, and the color-related signal is saturated for each pixel of the input image. Even if the color component is saturated in the input image by correcting the result of calculating the hue for each pixel and using the signal related to the color of each pixel and then converting the color space The special effect that the color space can be correctly converted can be achieved. For example, when the color space of the device that generates the input image signal is narrower than the color space that can be displayed by the image display device, or when there is a deviation in each color space, the color space of the input image signal is saturated. If it is not saturated in the color space of the image display device, it can be converted to a color space suitable for the image display device by the image processing device and the image processing method according to the present embodiment.

  The image processing apparatus according to this embodiment can be used as part of an image display apparatus such as a liquid crystal television. Further, the image processed by the image processing method shown in FIG. 2 can be displayed on an image display device such as a liquid crystal television. As a result, it is possible to display an image that has been correctly converted into a color space different from the color space of the input image signal, for example, a color space corresponding to a color reproduction region of a subsequent device (for example, a display unit).

  In the first embodiment, an image signal represented by a color signal in RGB format is input. However, the format of the input image is not limited to this, and a color-related signal is obtained and represented in that format. It goes without saying that the desired purpose can be achieved if the hue can be calculated from the signal.

Embodiment 2
In the first embodiment, the input image signal is an image signal represented by a color signal in RGB format. In the second embodiment, the luminance and color difference such as YCbCr are used instead of individual color component signals. An image processing apparatus and an image processing method in the case of an input image signal composed of signals will be described.

  FIG. 3 is a diagram illustrating the image processing apparatus according to the present embodiment. In FIG. 3, 111 is a saturation determination unit, 112 is a color distribution analysis unit, 113 is a color signal correction unit, and 114 is a color space conversion unit. The input image D0 is a signal composed of Y0 representing the luminance signal, CB0 representing the color difference signal of the Cb component, and CR0 representing the color difference signal of the Cr component, and represents a signal in the YCbCr format. R114, G114, and B114 are output images of the color space conversion unit 114 and represent RGB format signals.

  The saturation determination unit 111 outputs a result of determining whether or not a color-related signal is saturated for each pixel of the input image D0 as a saturation determination result D111. Here, since the input image D0 is a YCbCr format signal, it is determined whether or not at least one of the color difference components Cb and Cr is saturated, and the determination result is output as a saturation determination result D111.

  In this determination method, for example, if the absolute value of each of the color difference components Cb and Cr is a value equal to or greater than a predetermined threshold, it is determined that the corresponding color component is saturated, and the other colors What is necessary is just to determine that it is not saturated about a component. At this time, information indicating which color difference component is saturated may be included in the saturation determination result D111.

  The color distribution analysis unit 112 outputs the result of calculating the hue for each pixel of the input image D0 as the hue signal D112. Specifically, the color distribution is analyzed in the vicinity of each pixel of the input image D0. Based on the analysis result, the hue calculated for each pixel of the input image D0 is output as the hue signal D112.

  At this time, as a target of a region in the vicinity of each pixel, a pixel whose color component (Cr component, Cb component) is not saturated using the saturation determination result D111 may be the target. In this way, the hue is calculated from the pixels in the neighboring area for the pixel in which the color components (Cr component, Cb component) are not saturated, and the average value or the intermediate value is used as the hue of the pixel. It is possible to obtain a hue excluding pixels whose components are saturated.

  Next, although the hue is calculated from the RGB format signal in the first embodiment, the hue is calculated from the YCbCr format in the present embodiment. That is, the hue θ can be calculated by the second equation.

  The color difference signal correction unit 113 outputs a color component correction signal D113 obtained by performing color component correction on a pixel whose color component is saturated based on the saturation determination result D111 and the hue signal D112 for each pixel of the input image D0. . Specifically, when the saturation determination result D111 indicates that the color component is not saturated for each pixel of the input image D0, the input image D0 is output as it is as the color component correction signal D113, and the color component is saturated. If it is indicated that the color component is corrected, the color component is corrected from the input image D0 and the hue signal D112 of the pixel and output as a color component correction signal D113.

  Next, a correction method for correcting a color component from the input image D0 of the pixel and the hue signal D112 will be described. For example, a case where the Cb component at a certain pixel position is saturated will be described. In this case, the color component of the saturation determination result D111 at this pixel position is saturated. In order to correct the color component at this pixel position, the color signal correction unit 113 first replaces the saturated Cb component value with an unknown variable x. On the other hand, since the hue θ at this pixel position is obtained by the color distribution analysis unit 112, the equations of the second equation to the fifth equation are obtained.

この画素位置のＣｒ成分は飽和していないので第５式にＣｒ成分の値を入れてこの方程式を解けば未知の変数ｘを求めることができる。

Since the Cr component at this pixel position is not saturated, the unknown variable x can be obtained by entering the value of the Cr component into the fifth equation and solving this equation.

  The color space conversion unit 114 converts the color component correction signal D113 into a different color space and generates an output image D114. Here, the different color space is a color space that is different from the color space of the input image, and is convenient for a later circuit (not shown). The subsequent circuit is, for example, a display unit. In this case, a convenient color space refers to a color space corresponding to a color reproduction region of the display unit. If the subsequent stage of the color space conversion unit is another image processing apparatus, it indicates a color space that is convenient for the image processing apparatus.

  In FIG. 3, the color space conversion unit 114 simultaneously performs conversion from the YCbCr format to the RGB format. In this conversion, for example, calculation from the YCbCr format to the RGB format can be performed using a relational expression such as the first expression. If the color space format convenient for the subsequent circuit is other than the RGB format (for example, XYZ format, L * a * b format, etc.), conversion suitable for the format is performed.

  FIG. 4 is a flowchart showing the processing procedure of the image processing method according to the present embodiment. The illustrated image processing method includes a saturation determination step ST111, a color distribution analysis step ST112, a color signal correction step ST113, and a color space conversion step ST114. The saturation determination step ST111 is the same as the saturation determination hand unit 111, the color distribution analysis step ST112 is the same as the hue calculation unit 2, the color signal correction step ST113 is the same as the color signal correction unit 113, and the color space conversion step ST114 is the same as the color space conversion unit 114. To work.

  In the image processing method of the present embodiment, first, in the saturation determination step ST111, it is determined whether or not a signal relating to color (color difference signal in the present embodiment) is saturated for each pixel of the input image D0. Next, the hue is calculated for each pixel of the input image D0 in the color distribution analysis step ST112. At this time, if a pixel related to the color is saturated by the determination result of the saturation determination step ST111, a neighboring pixel when calculating the hue may be excluded from the target pixel for calculating the hue. Next, if it is determined in the color signal correction step ST113 that the color-related signal is saturated in the saturation determination step ST111, the hue calculated in the color distribution analysis step ST112 and the original input image D0 A corrected color component signal is generated. Next, in the color space conversion step ST114, the output image D114 is generated by converting into a different color space using the result of the color signal correction step ST113.

  As described above, the image processing apparatus and the image processing method according to the present embodiment determine whether or not a color-related signal is saturated for each pixel of the input image (saturation determination step ST111), and for each pixel of the input image. When the color-related signal is saturated, the hue is calculated for each pixel (color distribution analysis step ST112) and corrected using the color-related signal of each pixel (color signal correction step ST113). By converting the color space with (color space conversion step ST114), it is possible to obtain a special effect that the color space can be correctly converted even if the color component is saturated in the input image. For example, when the color space of the device that generates the input image signal is narrower than the color space that can be displayed by the image display device, or when there is a deviation in each color space, the color space of the input image signal is saturated. If it is not saturated in the color space of the image display device, it can be converted to a color space suitable for the image display device by the image processing device and the image processing method according to the present embodiment.

  The image processing apparatus according to this embodiment can be used as part of an image display apparatus such as a liquid crystal television. Further, the image processed by the image processing method shown in FIG. 4 can be displayed on an image display device such as a liquid crystal television. As a result, it is possible to display an image that has been correctly converted into a color space different from the color space of the input image signal, for example, a color space corresponding to a color reproduction region of a subsequent device (for example, a display unit).

Embodiment 3
In the first embodiment and the second embodiment, the color distribution analysis unit analyzes the color distribution of each pixel in the vicinity of the input image D0. However, in the third embodiment, the region division unit 115 further includes a region division. The color distribution of the input image D0 is analyzed for each region divided by the unit 115.

  FIG. 5 is a diagram illustrating an image processing apparatus according to the present embodiment. In FIG. 5, 111 is a saturation determination unit, 112 is a color distribution analysis unit, 113 is a color signal correction unit, 114 is a color space conversion unit, and 115 is a region division unit. The input image D0 is a signal composed of Y0 representing the luminance signal, CB0 representing the color difference signal of the Cb component, and CR0 representing the color difference signal of the Cr component, and represents a signal in the YCbCr format. R114, G114, and B114 are output images of the color space conversion unit 114 and represent RGB format signals.

  In the present embodiment, an area dividing unit 115 is further provided from the image processing apparatus according to the second embodiment. Since the operations of the saturation determination unit 111, the color signal correction unit 113, and the color space conversion unit 114 are the same as those in the second embodiment, description thereof is omitted.

  The area dividing unit 115 outputs the result of dividing the area near each pixel of the input image D0 as the area division result D115. Here, the area division is to divide the area in the vicinity of each pixel of the input image D0 into a pixel whose color is similar (or included in the same hue) as that of the corresponding pixel and a pixel that is not.

  The area division is performed based on, for example, a luminance component. For example, an edge is detected based on the luminance component Y0 in the vicinity of each pixel of the input image D0, and if the pixel is separated from each pixel of the input image D0 by the edge, it is determined that the pixel has a different color. If it is a pixel that is not separated by, it can be determined that the pixel is similar in color.

  In addition, if the luminance difference between each pixel of the input image D0 and a pixel located in the vicinity thereof is within a predetermined threshold, it may be determined that both pixels are in the same region. The threshold value used here may vary depending on the distribution of luminance values of pixels in the vicinity of each pixel of the input image. For example, the threshold value may be increased when the luminance value distribution is wide, and the threshold value may be decreased when the luminance value distribution is narrow. Note that the spread of the luminance value can be determined by, for example, standard deviation. Alternatively, the determination can also be made based on the difference between the maximum value and the minimum value of the luminance values of pixels in the vicinity of each pixel of the input image. Thus, by changing the threshold value according to the luminance value distribution of the pixels in the vicinity of each pixel of the input image, it can be expected to improve the accuracy of the region division.

  The color distribution analysis unit 112 outputs the result of calculating the hue for each pixel of the input image D0 as the hue signal D112. Specifically, the color distribution is analyzed in the vicinity of each pixel of the input image D0. Based on the analysis result, the hue calculated for each pixel of the input image D0 is output as the hue signal D112.

  At this time, the region division result D115 is used as a target of the region in the vicinity of each pixel, the region corresponding to the pixel position is set, and the color component (Cr component, Cb component) is saturated using the saturation determination result D111. Pixels that have not been processed are targeted. In this way, the hue is calculated from the pixels in the neighboring area for the pixel in which the color components (Cr component, Cb component) are not saturated, and the average value or the intermediate value is used as the hue of the pixel. It is possible to obtain a hue excluding pixels whose components are saturated.

  FIG. 6 is a flowchart showing the processing procedure of the image processing method according to the present embodiment. The illustrated image processing method includes a saturation determination step ST111, a color distribution analysis step ST112, a color signal correction step ST113, a color space conversion step ST114, and a region division step ST115. Saturation determination step ST111 is saturation determination hand 111, color distribution analysis step ST112 is hue calculation unit 2, color signal correction step ST113 is color signal correction unit 113, color space conversion step ST114 is color space conversion unit 114, The region dividing step ST115 performs the same operation as the region dividing unit 115.

  In the image processing method according to the present embodiment, first, in the saturation determination step ST111, it is determined whether or not a color-related signal is saturated for each pixel of the input image D0. Next, in a region division step ST115, for each pixel of the input image D0, a region near the region is divided, and a region for each pixel is associated. Next, the hue is calculated for each pixel of the input image D0 in the color distribution analysis step ST112. At this time, the neighboring pixels when calculating the hue are pixels in the region associated with the corresponding pixel position in the region division step ST115, and the color-related signal is saturated according to the determination result in the saturation determination step ST111. A pixel that is not considered as a target pixel may be the target pixel. Next, if it is determined in the color signal correction step ST113 that the color-related signal is saturated in the saturation determination step ST111, the hue calculated in the color distribution analysis step ST112 and the original input image D0 A corrected color component signal is generated. Next, in the color space conversion step ST114, the output image D114 is generated by converting into a different color space using the result of the color signal correction step ST113.

  The same processing result can be obtained regardless of the order of flow processing in the saturation determination step ST111 and the region division step ST115.

  As described above, the image processing apparatus according to the present embodiment further includes the area dividing unit 115, so that each pixel of the input image is divided into a pixel similar in color to the corresponding pixel and a pixel other than that in the vicinity. Since the division is performed, when the hue is calculated for the corresponding pixel in the color distribution analysis 112, the hue information from pixels included in a different area from the target pixel is not mixedly used. As a result, the hue of the corresponding pixel can be calculated with higher accuracy.

  The image processing apparatus according to this embodiment can be used as part of an image display apparatus such as a liquid crystal television. Further, the image processed by the image processing method shown in FIG. 6 can be displayed on an image display device such as a liquid crystal television. As a result, it is possible to display an image that has been correctly converted into a color space different from the color space of the input image signal, for example, a color space corresponding to a color reproduction region of a subsequent device (for example, a display unit).

101 Saturation Determination Unit 102 Color Distribution Analysis Unit 103 Color Signal Correction Unit 104 Color Space Conversion Unit

Claims (5)

A saturation determination unit that outputs, as a saturation determination result, a result of determining whether or not a color-related signal is saturated for each pixel of the input image;
A color distribution analysis unit that outputs the result of calculating the hue for each pixel as a hue signal;
A color signal correction unit that corrects a color component based on the hue signal and outputs a color component correction signal when the saturation determination result for each pixel indicates that the color component is saturated;
A color space conversion unit that generates an output image by converting the color component correction signal into a different color space ;
Each pixel of the input image is a signal composed of a luminance component and a color difference component,
The saturation determination unit outputs a result of determining whether or not the color difference component is saturated as a saturation determination result,
The color distribution analysis unit outputs a hue calculated using the saturation determination result and the color difference component for each pixel of the input image as the hue signal.
The color signal correction unit corrects the color difference component based on the hue signal and outputs it as a color component correction signal when the saturation determination result indicates that the color difference component is saturated for each pixel. To do
An image processing apparatus. An area dividing unit that outputs a result of dividing an area in the vicinity of each pixel of the input image into a pixel having a color similar to that of each pixel and a pixel that is not so as an area dividing result;
The color distribution analysis unit, wherein, characterized in that outputs a hue calculated using said saturation determination result and the segmentation result and the color difference components for each pixel of the input image as the hue signal Item 8. The image processing apparatus according to Item 1 . The image processing apparatus according to claim 1 or 2 ,
A display unit that displays the output image from the image processing device in a predetermined color reproduction region;
The image display device, wherein the color space conversion unit included in the image processing device converts an input color component correction signal into the predetermined color reproduction region. A saturation determination step of outputting a result of determining whether or not a signal relating to color is saturated for each pixel of the input image as a saturation determination result;
A color distribution analysis step of outputting the result of calculating the hue for each pixel as a hue signal;
A color signal correction step for correcting the color component based on the hue signal and outputting it as a color component correction signal when the saturation determination result from the saturation determination step for each pixel indicates that the color component is saturated When,
Bei example a color space conversion step of generating an output image is converted into a different color space from the color component correction signal,
Each pixel of the input image is a signal composed of a luminance component and a color difference component,
The saturation determination step outputs a result of determining whether or not the color difference component is saturated as a saturation determination result,
The color distribution analysis step outputs a hue calculated using the saturation determination result and the color difference component for each pixel of the input image as the hue signal.
In the color signal correction step, when the saturation determination result indicates that the color difference component is saturated for each pixel, the color difference component is corrected based on the hue signal and output as a color component correction signal. To do
An image processing method. A region dividing step of outputting, as a region division result, a result of dividing a region in the vicinity of each pixel of the input image into a pixel having a color similar to that of each pixel and a pixel that is not so;
The color distribution analysis step, according to, characterized in that for outputting a hue calculated using said saturation determination result and the segmentation result and the color difference components for each pixel of the input image as the hue signal Item 5. The image processing method according to Item 4 .

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