JP5314585B2 - Display device - Google Patents

Description

  The present invention relates to a display device, and more particularly to a display device capable of expressing bright and vivid colors even with a display that supports a narrow color gamut such as the ITU-R BT.709 standard.

  In recent years, liquid crystal displays have been widely used in display devices such as television receivers. In a liquid crystal display, the liquid crystal panel itself on which image display is performed does not emit light, and the liquid crystal panel modulates illumination light emitted from an adjacent backlight to form an image.

  Accordingly, the displayed image depends not only on the liquid crystal panel but also on the luminance of the illumination light, and the luminance of the backlight is adjusted in accordance with the video signal. In particular, a technique for controlling the luminance of illumination light in accordance with an average luminance level (APL: Average Picture Level) in a video signal is described in Patent Document 1, for example.

  In this technique, the average luminance level (APL) of the video signal input to the liquid crystal display is detected. When the APL is large, the luminance of the illumination light from the backlight is lowered, and when the APL is small, the luminance of the illumination light is reduced. Control to increase brightness. As a result, even if the APL of the video signal changes, an image can be displayed with a substantially constant display luminance.

  On the other hand, a movement to use a semiconductor light source such as an LED (Light Emitting Diode) as a light source of a display device using a liquid crystal display as described above is in full swing. A great advantage of using such a semiconductor light source is that a display having a wide color gamut can be realized. This is because a semiconductor light source has a sharp spectrum. For example, a display device using a semiconductor light source for three primary colors of red, green, and blue is a CRT (Cathode Ray Tube) display or a liquid crystal using a cold cathode tube. Compared to a conventional image display device such as a display, it has a wide color gamut and can express bright and vivid colors.

  In addition, for example, a color gamut that can be displayed with a video signal of digital broadcasting (HDTV) is defined by the ITU-R BT.709 standard or the like. As an example of a standard for expressing a color gamut exceeding the range of the color gamut (narrow color gamut) expressed by the luminance signal and the color difference signal defined by the ITU-R BT.709 standard, the xvYCC standard Is proposed by the international standard (IEC 61966-2-4). The feature of the xvYCC standard is that the color space has been expanded to represent a wide color gamut while ensuring compatibility with the ITU-R BT.709 standard.

JP-A-8-201812

  However, the display corresponding to the above wide color gamut (xvYCC standard, etc.) is not widespread, and the display corresponding to the conventional narrow color gamut (ITU-R BT.709 standard, etc.) has become mainstream. ing. Even in this narrow color gamut display, there is a demand to express bright and vivid colors like a wide color gamut display. According to the technique described in Patent Document 1 described above, the display luminance is maintained constant regardless of the change in APL by controlling the backlight luminance in accordance with the change in APL of the video signal. Such color expression cannot be realized.

  The present invention has been made in view of the above circumstances, and provides a display device capable of performing bright and vivid color expression like a wide color gamut display even with a conventional narrow color gamut display. Objective.

In order to solve the above-described problem, a first technical means of the present invention is a display device including a brightness adjusting unit that adjusts the brightness of an input video signal corresponding to a predetermined color space, and displays on the display device. A display line indicating a range of possible color spaces, a target line indicating target luminance of the input video signal, and a determination line for determining whether the luminance of the input video signal is higher or lower than the target line The display line, the target line, and the discrimination line are set as a function of luminance and saturation for each hue, and the luminance adjustment unit is a pixel that constitutes the input video signal. And detecting the hue, saturation, and luminance of the pixel, and comparing the luminance of the pixel with the discrimination line, the luminance of the pixel is set to the target luminance of the target line. The combined adjusted, the line setting unit sets a target luminance of the predetermined chroma or high chroma portion of the target line, as well as set to be lower than the display line, the determination line, based on the display line And the brightness adjusting unit determines that the brightness of the pixel is based on the target line and the discrimination line when the brightness of the pixel is lower than the discrimination line. Higher than and lower than the target line, and when the luminance of the pixel is equal to or higher than the determination line, the display line, the target line, and the determination line in which the brightness has said adjusted to be higher than the target line That.

A second technical means is a display device including a brightness adjusting unit that adjusts the brightness of an input video signal corresponding to a predetermined color space, the display line indicating a range of a color space that can be displayed on the display device, A line setting unit for setting a target line indicating a target luminance of the input video signal and a determination line for determining whether the luminance of the input video signal is higher or lower than the target line; The line, the target line, and the discrimination line are set as a function of luminance and saturation for each hue, and the luminance adjustment unit detects the hue, saturation, and luminance of the pixels constituting the input video signal. , based on a result of comparison between the luminance and the determination line of the pixel, and adjust the brightness of the pixel in the target luminance of the target line, the line setting unit The target brightness low low chroma portion than a predetermined saturation target lines, as well as set to be lower than the display line based on the display line, the determination line, based on said display line The luminance adjustment unit is set between the display line and the target line, and the luminance adjustment unit determines that the luminance of the pixel is based on the target line and the determination line when the luminance of the pixel is lower than the determination line. If the luminance of the pixel is equal to or higher than the determination line, the luminance of the pixel is higher than the luminance based on the display line, the target line, and the determination line. and wherein the adjusted to be higher than is low and the target line Those were.

A third technical means is characterized in that, in the first or second technical means, the brightness adjusting unit holds the display line, the target line, and the discrimination line as a lookup table. .

According to a fourth technical means, in the third technical means, the display line and the target line are set for each predetermined hue.

According to a fifth technical means, in the fourth technical means, the brightness adjusting unit is adjacent to the pixel hue and has the display line and the target line when the hue of the pixel is other than the predetermined hue. Is adjusted based on the display line, the target line, and the discrimination line, and the luminance of the pixel hue is interpolated based on the adjusted luminance of the two hues. It is characterized by doing.

  According to the present invention, even a conventional narrow color gamut display can emphasize primary colors with high saturation and low luminance, so that bright and vivid color expression like a wide color gamut display can be performed.

It is a block diagram which shows the structural example of the display apparatus which concerns on one Embodiment of this invention. It is a figure for demonstrating an example of the display line, target line, and discrimination | determination line which are set by the line setting part. It is a figure for demonstrating an example of the luminance adjustment method by a luminance adjustment part. It is a figure for demonstrating an example of the luminance adjustment method in the case of an intermediate | middle hue. It is a figure for demonstrating an example of the setting method of the discrimination line by a line setting part. It is a figure for demonstrating other embodiment of the luminance adjustment method by the display apparatus which concerns on this invention. It is a figure for demonstrating the other example of the luminance adjustment method by a luminance adjustment part. It is a figure for demonstrating an example of the setting method of the target line by a line setting part. It is a figure for demonstrating the other example of the setting method of the target line by a line setting part.

  Hereinafter, preferred embodiments according to a display device of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a block diagram illustrating a configuration example of a display device according to an embodiment of the present invention. In the figure, 1 denotes the display device. The display device 1 includes a decoding unit 11 that decodes the broadcast signal 2 and extracts an input video signal corresponding to a predetermined color space, a luminance adjustment unit 12 that adjusts the luminance of the input video signal, and an output after luminance adjustment. A video processing unit 13 for performing various video processing on the video signal, a display unit 14 such as an LCD (Liquid Crystal Display), a line setting unit 15 for setting a display line, a target line, and a discrimination line, which will be described later, And an operation unit 16 for a user to operate the display device 1.

  The luminance adjustment unit 12 includes a memory that holds the display line, the target line, and the discrimination line set by the line setting unit 15 as an LUT (lookup table) 12a.

  In the above, the color space of the input video signal is, for example, a narrow color gamut space of the ITU-R BT.709 standard. The brightness adjusting unit 12 adjusts the brightness of the input video signal, and outputs the video signal after the brightness adjustment as an output video signal. Further, a YCbCr (Y: luminance, CbCr: color difference) signal is acquired from the broadcast signal 2, and the YCbCr signal and the RGB signal can be converted into each other by a known conversion formula.

FIG. 2 is a diagram for explaining an example of a display line, a target line, and a determination line set by the line setting unit 15. In the figure, the vertical axis is L ^* (luminance), the horizontal axis is Cu′v ′ (saturation), and the hue “R (red)” is shown. Here, the color space that is determined by the input video signal and represents the entire color that can be represented by the input video signal is, for example, the color space of the ITU-R BT.709 standard. Cu′v ′ (saturation) in this example corresponds to the distance between W (white) and R (red) on the well-known u′v ′ chromaticity diagram (CIE1976UCS chromaticity diagram).

  The line setting unit 15 sets the display line 3 indicating the range of the color space that can be displayed on the display device 1, the target line 4 indicating the target luminance of the input video signal, and whether the luminance of the input video signal is higher than the target line 4. A discrimination line 5 for discriminating whether or not to lower is set. In addition, the display line 3, the target line 4, and the discrimination line 5 in this specification are for respectively dividing boundaries, and the shape thereof is not particularly limited.

  As shown in FIG. 2, the display line 3, the target line 4, and the discrimination line 5 are set as functions of luminance and saturation for each hue. The display line 3 is held in advance by the display device 1 as the LUT 12a. The target line 4 is held in advance as the LUT 12a by the display device 1 in the same manner as the display line 3. However, for example, the target line 4 may be a boundary line that is a boundary between the object color and the emission color determined based on the subjective evaluation test. . In this specification, this boundary line is defined as CMI (Color Mode Index) = 100.

  Briefly, the boundary line of CMI = 100 is determined subjectively by determining whether a plurality of subjects appear to be object colors or luminescent colors for a certain color. The object color here is a color of an object that reflects or transmits light, and includes a reflecting object that reflects light and a transmissive object that transmits light. The emission color means the color of light emitted from the light source. This CMI is described in “M.Okui et al.,“ Relationship Between Upper-limit Luminance for Surface-color Mode Appearance and Preferred Gamut on Wide Gamut Display ”, SID 09 DIGEST, pp. 1018-1021”. Specific description is omitted.

  In the present invention, the discrimination line 5 is further set. The determination line 5 is provided to determine whether the luminance of the input video signal is higher or lower than the target line 4 and is set separately from the target line 4. Thereby, the luminance of each pixel of the input video signal is compared with the discrimination line 5, and the luminance of each pixel is adjusted according to the target luminance of the target line 4 based on the comparison result.

  That is, the luminance adjustment unit 12 detects the hue, saturation, and luminance of a pixel that constitutes an input video signal corresponding to a narrow color gamut (for example, ITU-R BT.709 standard), and discriminates it from the luminance of the pixel. A process of comparing with line 5 is performed. This process is performed for each pixel. For the hue, saturation, and luminance of each pixel constituting the input video signal, for example, a value (0 to 255) of the YCbCr signal of the input video signal is converted into an RGB signal, and the converted RGB signal is well known. This can be obtained by converting to u′v ′ chromaticity coordinates using the following conversion formula.

  Here, as described above, the human eye recognizes the object color below the target line 4 and the light emission color above the target line 4. In the example of FIG. 2, the line setting unit 15 sets the target luminance of the high saturation portion (for example, the portion of 128 to 255) of the target line 4 to be lower than the display line 3, and sets the determination line 5 to The display line 3 is set to be lower than the target line 4. That is, the target line 4 is set between the display line 3 and the discrimination line 5.

  Then, in the case of the object color pixel P2 having a luminance lower than that of the determination line 5, the luminance adjustment unit 12 has the luminance of the pixel P2 higher than the luminance based on the target line 4 and the determination line 5, and the target line 4 Adjust so that it is lower. As a result, it is possible to raise the luminance of the low-brightness object color among the high-saturation object colors to the vicinity of the target line 4, so that even a conventional narrow color gamut display is bright and vivid like a wide color gamut display. Color expression can be performed.

  The pixel P1 of the object color having a luminance of the discrimination line 5 or higher may be maintained as it is without adjusting the luminance. However, if more vivid color expression is desired, the display line 3, the target line 4, Based on the determination line 5, the luminance of the pixel P <b> 1 may be adjusted to be higher than that of the target line 4. As a result, the pixel P1, which was originally an object color, looks like a light emission color, so that more vivid color expression can be performed together with the pixel P2 whose luminance is increased as described above. Specifically, the brightness is adjusted by the method described in FIG.

FIG. 3 is a diagram for explaining an example of a luminance adjustment method by the luminance adjustment unit 12. In the figure, the vertical axis is L ^* (luminance), the horizontal axis is Cu′v ′ (saturation), L is the luminance of the pixel before adjusting the luminance of the input video signal, and L ′ is the luminance after adjusting the luminance of the input video signal. The luminance of the pixel, L0 represents the luminance of the display line 3 at a certain saturation, L1 represents the luminance of the target line 4 at a certain saturation, and L2 represents the luminance of the discrimination line 5 at a certain saturation.

1. In the case of the pixel P2 determined as L <L2 by the determination line 5, L ′ is calculated based on the following equation (1).
L ′ = L × L1 / L2 (1)
2. In the case of the pixel P1 determined as L ≧ L2 by the determination line 5, L ′ is calculated based on the following equation (2).
L ′ = {(L−L2) × (L0−L1) / (L0−L2)} + L1 (2)

  The above 2. The pixel P1 includes a light emission color that originally has a higher luminance than the target line 4. However, in consideration of the luminance balance, it is preferable to increase the luminance of these light emission colors according to the expression (2). .

  In this way, when displaying a video signal of a narrow color gamut, the luminance of the high-saturation pixel P2 below the determination line 5 is adjusted to be higher than the current luminance and lower than the target line 4, The brightness of the high-saturation pixel P1 above the determination line 5 is adjusted as it is or higher than the target line 4. Thus, even a conventional narrow color gamut display can perform bright and vivid color expression like a wide color gamut display.

  FIG. 4 is a diagram for explaining an example of a luminance adjustment method in the case of an intermediate hue. It is not appropriate to set the display line 3 and the target line 4 to each hue from the viewpoint of a heavy processing load. For this reason, the display line 3 and the target line 4 are set for each predetermined hue such as R, G, B, or R, G, B, C, M, Y, for example, to adjust the luminance of the intermediate hue. May be performed by interpolation processing from these hues.

  In this case, when the hue of the pixel constituting the input video signal is other than a predetermined hue, the luminance adjusting unit 12 has two hues adjacent to the pixel hue and having the display line 3 and the target line 4 set. The luminance is adjusted based on the display line 3, the target line 4, and the discrimination line 5, and the luminance of the pixel hue is interpolated based on the adjusted luminance of the two hues.

  The interpolation process will be specifically described based on the example of FIG. In this example, the hue gradation of the pixel to be interpolated (interpolation target pixel) is (r, g, b), and the adjacent hue of this pixel is hue R and hue Y (r> g> b). For each of the point (r, b, b) on the hue R and the point (r, r, b) on the hue Y, the luminance L ′ is calculated by the method described with reference to FIG. Then, based on the luminance L ′ of the hue R and the luminance L ′ of the hue Y obtained by calculation, the luminance of the hue of the interpolation target pixel is interpolated. For example, linear interpolation between the luminance L ′ of the hue R and the luminance L ′ of the hue Y can be considered.

FIG. 5 is a diagram for explaining an example of a method for setting the discrimination line 5 by the line setting unit 15. The determination line 5 is set below the target line 4 based on the display line 3. The luminance adjustment unit 12 holds the discrimination line 5 set by the line setting unit 15 as an LUT 12a. Specifically, it is calculated based on the following formula. Here, the hue “red” will be described as an example.
L2 = L0−ΔL (3)
ΔL = L0 × α × C1 / C0 (α is a constant) Formula (4)
However, C0 is the maximum saturation of the hue “red”, L0 is the brightness of the display line 3 when the saturation is C1, and L2 is the brightness of the discrimination line 5 when the saturation is C1.

The user operates the operation unit 17 to change the L ^* value according to the value of Cu′v ′. Since the inclination of the target line 4 varies depending on the hue, the determination line 5 also varies in inclination depending on the hue. Specifically, the constant α in Expression (4) is changed so that the determination line 5 is positioned below the target line 4. Thus, an appropriate constant α is determined. At this time, it is preferable to perform the setting process while checking the state of change on the screen. And (DELTA) L is calculated about a certain saturation C1, and the brightness | luminance L2 of the discrimination | determination line 5 can be calculated | required by Formula (3).

  In this way, the discrimination line 5 is set for each predetermined hue such as R, G, B, or R, G, B, C, M, Y, and the LUT 12a together with the display line 3 and the target line 4. Keep as.

  In this embodiment, as an example of the target line 4, CMI = 100, which is the boundary line between the object color and the emission color, is set. However, the inclination of the target line 4 is made closer to the inclination of the display line 3 (that is, FIG. The target line 4 may be set on the high luminance side by shifting in the arrow direction shown in FIG. Thereby, since the target luminance is increased, more vivid color expression can be performed.

  Here, if the target line 4 is shifted to the higher luminance side than the boundary line (CMI = 100) as described above, it hits the display line 3 at a certain luminance and cannot be shifted further to the higher luminance side. Therefore, in such a case, the luminance on the low saturation side (achromatic color side) may be lowered to increase the luminance on the relatively high saturation side so that the primary color appears vividly. An embodiment in this case will be described below.

(Second Embodiment)
FIG. 6 is a diagram for explaining another embodiment of the luminance adjustment method by the display device 1 according to the present invention. In the present embodiment, the line setting unit 15 sets the target luminance of the low saturation portion of the target line 4 to be lower than that of the display line 3 based on the display line 3. Specifically, the brightness is adjusted by the method described in FIG. Further, it is assumed that the target line 4 and the discrimination line 5 in the present embodiment can be variably set based on the display line 3.

FIG. 7 is a diagram for explaining another example of the luminance adjustment method by the luminance adjustment unit 12. In the figure, the vertical axis is L ^* (luminance), the horizontal axis is Cu′v ′ (saturation), L is the luminance of the pixel before adjusting the luminance of the input video signal, and L ′ is the luminance after adjusting the luminance of the input video signal. The luminance of the pixel, L0 represents the luminance of the display line 3 at a certain saturation, L1 represents the luminance of the determination line 5 at a certain saturation, and L2 represents the luminance of the target line 4 at a certain saturation.

3. In the case of the pixel P2 determined as L <L1 by the determination line 5, L ′ is calculated based on the following equation (5).
L ′ = L × L2 / L1 Formula (5)
4). In the case of the pixel P1 determined as L ≧ L1 by the determination line 5, L ′ is calculated based on the following equation (6).
L ′ = {(L−L1) × (L0−L2) / (L0−L1)} + L2 (6)

  The above 3. However, the pixel P2 originally includes colors having lower luminance than the target line 4. However, considering the luminance balance, it is preferable to reduce the luminance of these colors using the equation (5).

  In FIG. 7, the line setting unit 15 sets the discrimination line 5 between the display line 3 and the target line 4 based on the display line 3. In the case of the pixel P <b> 2 having a luminance lower than that of the determination line 5, the luminance adjustment unit 12 adjusts the luminance of the pixel P <b> 2 to be lower than that of the target line 4 based on the target line 4 and the determination line 5.

  In addition, the pixel P1 having a luminance equal to or higher than the determination line 5 may be maintained as it is without adjusting the luminance. However, when a more vivid color expression is desired, the display line 3, the target line 4, and the determination line 5, the brightness of the pixel P1 may be adjusted to be lower than the current brightness and higher than the target line 4.

  In this way, when displaying a video signal in a narrow color gamut, the luminance of the low-saturation pixel P2 below the discrimination line 5 is adjusted to be lower than that of the target line 4, and the discrimination line 5 or higher is also displayed. The brightness of the low-saturation pixel P <b> 1 is adjusted as it is or so as to be lower than the current brightness and higher than the target line 4. As a result, the luminance on the low saturation side (achromatic color side) can be lowered to relatively increase the luminance on the high saturation side, and the primary colors can be made to appear vividly.

  In the present embodiment, similarly to the method described with reference to FIG. 4, the display line 3 and the target line 4 are, for example, R, G, B, or R, G, B, C, M. , Y and the like for each predetermined hue, and the luminance adjustment of the intermediate hue can be performed by interpolation processing from these hues.

FIG. 8 is a diagram for explaining an example of a method for setting the target line 4 by the line setting unit 15. The target line 4 is set to be lower than the display line 3 based on the display line 3. Then, the luminance adjusting unit 12 holds the target line 4 set by the line setting unit 15 as the LUT 12a. Specifically, it is calculated based on the following formula. Here, the hue “red” will be described as an example.
L2 = L0−ΔL (7)
ΔL = L0 × α × C1 / C0 (α is a constant) (8)
However, C0 is the maximum saturation of the hue “red”, L0 is the luminance of the display line 3 when the saturation is C1, and L2 is the luminance of the target line 4 when the saturation is C1.

As shown in FIG. 8, when the target line 4 is set, the luminance L ^* of the display line 3 is changed so that the primary color luminance on the high saturation side is not changed and the lower saturation side (achromatic color side) is greatly reduced. Also, since the white luminance needs to be constant, the constant α is made constant for all hues. In this way, the luminance L2 of the target line 4 can be obtained for a certain saturation C1.

  Further, the line setting unit 15 can set the discrimination line 5 between the display line 3 and the target line 4 based on the display line 3 by the same method as described above. Then, the luminance adjusting unit 12 holds the discrimination line 5 set by the line setting unit 15 together with the target line 4 as an LUT 12a.

FIG. 9 is a diagram for explaining another example of a method for setting the target line 4 by the line setting unit 15. 9A shows a setting state of the target line 4 in the hue A, and FIG. 9B shows a setting state of the target line 4 in the hue B. As described above, the inclination of the target line 4 (D2 in the figure) may be changed according to the hue while the white luminance decrease amount (D1 in the figure) is constant in all hues.
L2 = L0−ΔL (9)
ΔL = L0 × α × {1-C1 / (C0−β) (α and β are constants) (10)
However, C0 is the maximum saturation of the hues A and B, L0 is the luminance of the display line 3 when the saturation is C1, and L2 is the luminance of the target line 4 when the saturation is C1.

  In the case of this example, the inclination of the target line 4 is changed by changing the constant β of the above formula (9) according to the hue. Thereby, since the inclination of the target line 4 is set for each hue, color display can be performed more effectively. In this way, the luminance L2 of the target line 4 can be obtained for a certain saturation C1.

  Here, in the first embodiment described with reference to FIG. 3, the luminance of the high-saturation pixel is increased in accordance with the target luminance of the high-saturation portion, and in the second embodiment described with reference to FIG. In accordance with the target luminance of the portion, the luminance of the low-saturation pixel is lowered to increase the luminance of the relatively high-saturation pixel. The luminance adjustment methods according to the first embodiment and the second embodiment may be implemented individually, or may be implemented in combination of both. By combining both, it is possible to further enhance the primary color luminance of high saturation and low luminance.

  As described above, according to the present invention, even in a conventional narrow color gamut display, it is possible to enhance the primary color luminance of high saturation and low luminance, so that a bright and vivid color expression like a wide color gamut display is performed. Can do. The present invention can also be applied to a multi-primary color display in which the primary color luminance is reduced in principle.

DESCRIPTION OF SYMBOLS 1 ... Display apparatus, 2 ... Broadcast signal, 3 ... Display line, 4 ... Target line, 5 ... Discrimination line, 11 ... Decoding part, 12 ... Luminance adjustment part, 12a ... LUT, 13 ... Image processing part, 14 ... Display part , 15 ... line setting unit, 16 ... operation unit.

Claims (5)

A display device including a luminance adjustment unit that adjusts the luminance of an input video signal corresponding to a predetermined color space,
A display line indicating a range of color space that can be displayed by the display device; a target line indicating a target luminance of the input video signal; and determining whether the luminance of the input video signal is higher or lower than the target line. A line setting unit for setting a discrimination line for
The display line, the target line, and the discrimination line are set as a function of luminance and saturation for each hue,
The luminance adjustment unit detects a hue, saturation, and luminance of a pixel constituting the input video signal, and determines the luminance of the pixel based on a result of comparing the luminance of the pixel and the determination line. Adjust according to the target brightness of the line ,
The line setting unit sets a target luminance of a high saturation portion equal to or higher than a predetermined saturation of the target line so as to be lower than the display line, and sets the determination line from the target line based on the display line. Set to lower,
The luminance adjustment unit may be configured such that when the luminance of the pixel is lower than the determination line, the luminance of the pixel is higher than the luminance and lower than the target line based on the target line and the determination line. And when the luminance of the pixel is equal to or higher than the determination line, the luminance of the pixel is adjusted to be higher than the target line based on the display line, the target line, and the determination line. A display device characterized by that. A display device including a luminance adjustment unit that adjusts the luminance of an input video signal corresponding to a predetermined color space,
A display line indicating a range of color space that can be displayed by the display device; a target line indicating a target luminance of the input video signal; and determining whether the luminance of the input video signal is higher or lower than the target line. A line setting unit for setting a discrimination line for
The display line, the target line, and the discrimination line are set as a function of luminance and saturation for each hue,
The luminance adjustment unit detects a hue, saturation, and luminance of a pixel constituting the input video signal, and determines the luminance of the pixel based on a result of comparing the luminance of the pixel and the determination line. Adjust according to the target brightness of the line,
The line setting unit sets a target luminance of a low saturation portion lower than a predetermined saturation of the target line so as to be lower than the display line based on the display line, Set between the display line and the target line based on the display line,
The brightness adjustment unit, when the luminance of the pixel is lower than the determination line, on the basis of the target line and the determination line, the luminance of the pixels is adjusted to be lower than the target line, also, the When the luminance of the pixel is equal to or higher than the determination line, the luminance of the pixel is adjusted to be lower than the luminance and higher than the target line based on the display line, the target line, and the determination line. A display device characterized by that. 3. The display device according to claim 1, wherein the luminance adjustment unit holds the display line, the target line, and the determination line as a lookup table. The display device according to claim 3 , wherein the display line and the target line are set for each predetermined hue. 5. The display device according to claim 4 , wherein when the hue of the pixel is other than the predetermined hue, the luminance adjustment unit is adjacent to the hue of the pixel and the display line and the target line are set. The brightness of two hues is adjusted based on the display line, the target line, and the discrimination line, and the brightness of the hue of the pixel is interpolated based on the adjusted brightness of the two hues. Display device.

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