JP2009284273A - Signal processor and projection type image display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal processor and a projection type image display effectively utilizing the color reproduction range of a display while suppressing a difference between the color coordinates of an image and those of an actual object to some extent. <P>SOLUTION: The signal processor 200 includes: a color coordinates adjustment section 210 for performing color coordinates adjustment processing according to the color reproduction range of the display; a luminance adjustment section 220 for performing luminance adjustment processing; a display element control section 240 for generating an image output signal by the color coordinates adjusted by the color coordinates adjustment processing and a luminance component adjusted by the luminance adjustment processing; and a ratio control section 230 for controlling a color coordinates adjustment contribution rate given to the image output signal by the color coordinates adjustment processing and a luminance component contribution rate given to the image output signal by the luminance adjustment processing according to the chroma of an image input signal. At the ratio control section 230, the higher the chroma of the image input signal in first and second specific hues, the larger the color coordinates adjustment contribution rate and the smaller the luminance component contribution rate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a signal processing device that converts a video input signal into a video output signal and a projection video display device.

  Conventionally, a display device that displays an image captured by an imaging device such as a camera is known. As a light source for irradiating light to a display device, a solid light source (for example, LD; Laser Diode or LED; Light Emitting Diode) having a wide color reproduction range has been developed. A case where the color reproduction range of such a display device is different from the color reproduction range of the imaging device is assumed.

On the other hand, when the color reproduction range of an input device (for example, an imaging device) is wider than the color reproduction range of an output device (for example, a display device), a technique for reducing the color reproduction range of the input device has been proposed ( For example, Patent Document 1). Specifically, by changing the direction in which the color reproduction range is reduced for each hue, an image that looks visually natural is output.
JP 2000-324350 A

  Here, consider a case where the color reproduction range of an output device (for example, a display device) is wider than the color reproduction range of an input device (for example, an imaging device). In such a case, when the output device displays an image in accordance with the video input signal input from the input device, the color coordinates of the image are wider than the actual color coordinates. The color coordinates are coordinates defined by saturation and hue.

  On the other hand, it is conceivable to apply the above-described technique in order to bring the color coordinates of an image closer to the actual color coordinates. However, if the color reproduction range of the output device is simply reduced, the color reproduction range of the output device (display device) cannot be used effectively.

  Accordingly, the present invention has been made to solve the above-described problems, and effectively uses the color reproduction range of the display device while suppressing the difference between the color coordinates of the image and the actual color coordinates to some extent. It is an object of the present invention to provide a signal processing apparatus and a projection display apparatus that can perform the above-described processing.

    A signal processing device according to a first feature is a signal processing device that converts a video input signal into a video output signal and outputs the video output signal to a display device, according to a color reproduction range of the display device. A color coordinate adjustment unit that performs color coordinate adjustment processing for adjusting color coordinates of the video input signal, a luminance adjustment unit that performs luminance adjustment processing for adjusting a luminance component of the video input signal, and adjustment by the color coordinate adjustment processing An output signal generation unit configured to generate the video output signal based on the adjusted color coordinates and the luminance component adjusted by the luminance adjustment process, and the color coordinate adjustment process is performed according to a saturation of the video input signal. A control unit for controlling a color coordinate adjustment contribution degree to be given to the output signal and a luminance component contribution degree to be given to the video output signal by the luminance adjustment processing. The control unit increases the color coordinate adjustment contribution and decreases the luminance component contribution as the saturation of the video input signal is higher in the first specific hue or the second specific hue.

    According to this feature, the ratio control unit has a case where the saturation of the video input signal is high in the first specific hue or the second specific hue, that is, a case where the difference between the color coordinates of the image and the actual color coordinates is large. The color coordinate adjustment contribution is increased and the luminance component contribution is decreased.

  Therefore, in the case where the difference between the color coordinates of the image and the actual color coordinates is large, the difference between the color coordinates of the image and the actual color coordinates can be suppressed.

  On the other hand, in the case where the saturation of the video input signal is low in the first specific hue or the second specific hue, that is, the case where the difference between the color coordinates of the image and the actual color coordinates is small, the ratio control unit While reducing the coordinate adjustment contribution, the luminance component contribution is increased.

  Therefore, when the difference between the color coordinates of the image and the actual color coordinates is small, the color reproduction range of the display device can be used effectively.

  The signal processing device according to the first feature further includes an acquisition unit that acquires the luminance of an image in accordance with the video input signal. The control unit increases the decrease amount of the luminance component of the video input signal in the luminance adjustment process as the luminance acquired by the acquisition unit is higher.

  The signal processing apparatus according to the first feature further includes an acquisition unit that acquires a hue for each pixel constituting the image in accordance with the video input signal. The first specific hue has a first hue width including a first target hue, and the second specific hue has a second hue width including a second target hue. The control unit increases the color coordinate adjustment contribution degree and decreases the luminance component contribution degree as the hue acquired by the acquisition unit is closer to the first target hue, and is acquired by the acquisition unit. The closer the hue is to the second target hue, the higher the color coordinate adjustment contribution and the lower the luminance component contribution.

  The signal processing apparatus according to the first feature further includes an acquisition unit that acquires a hue for each pixel constituting the image in accordance with the video input signal. The control unit increases the luminance component contribution degree and the color coordinate adjustment contribution degree as the first hue distribution width, which is a width in which the hue obtained by the obtaining unit is distributed in the first specific hue, is wider. The luminance component contribution is increased and the color coordinate adjustment contribution is increased as the second hue distribution width, which is the width in which the hue acquired by the acquisition unit is distributed in the second specific hue, is increased. Reduce.

  The signal processing device according to the first feature further includes an acquisition unit that acquires saturation for each pixel constituting the image in accordance with the video input signal. The controller increases the luminance component contribution and decreases the color coordinate adjustment contribution as the saturation acquired by the acquisition unit is higher.

  The signal processing device according to the first feature further includes an acquisition unit that acquires saturation for each pixel constituting the image in accordance with the video input signal. The control unit increases the luminance component contribution and increases the color coordinate adjustment as the first saturation distribution width, which is a width in which the saturation acquired by the acquisition unit in the first specific hue, is wide. The contribution of the luminance component is decreased as the second saturation distribution width, which is a width in which the saturation acquired by the acquisition unit in the second specific hue is widened, increases the luminance component contribution, and the color coordinates Reduce adjustment contribution.

  In the signal processing device according to the first feature, the control unit controls the luminance component contribution degree and the color coordinate adjustment contribution degree for each pixel.

  A projection display apparatus according to a second feature includes a signal processing apparatus according to claim 1, a display apparatus that displays an image according to a video output signal output from the signal processing apparatus, and a display that is displayed by the display apparatus. Projection means for projecting the projected image.

  According to the present invention, a signal processing device and a projection display capable of effectively using the color reproduction range of a display device while suppressing the difference between the color coordinates of the image and the actual color coordinates to some extent. An apparatus can be provided.

  Hereinafter, a projection display apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[First Embodiment]
(Configuration of projection display device)
Hereinafter, the configuration of the projection display apparatus according to the first embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of a projection display apparatus 100 according to the first embodiment.

  As shown in FIG. 1, the projection display apparatus includes a plurality of light source units 10, a plurality of fly-eye lens units 20, a plurality of liquid crystal panels 30, a cross dichroic prism 40, and a projection lens unit 50. .

  The plurality of light source units 10 are a light source unit 10R, a light source unit 10G, and a light source unit 10B. Each light source unit 10 is a unit composed of a plurality of solid state light sources. The solid light source is, for example, an LD (Laser Diode) or an LED (Light Emitting Diode). The light source unit 10R includes a plurality of solid light sources (10-1R to 10-6R) that emit red component light. The light source unit 10G includes a plurality of solid light sources (10-1G to 10-6G) that emit green component light. The light source unit 10B includes a plurality of solid light sources (10-1B to 10-6B) that emit blue component light.

  The plurality of fly-eye lens units 20 are a fly-eye lens unit 20R, a fly-eye lens unit 20G, and a fly-eye lens unit 20B. Each fly eye lens unit 20 includes a fly eye lens 21 and a fly eye lens 22. Each of the fly eye lens 21 and the fly eye lens 22 is composed of a plurality of minute lenses. Each microlens condenses the light emitted from each light source unit 10 so that the light emitted from each light source unit 10 is irradiated on the entire surface of each liquid crystal panel 30.

  The plurality of liquid crystal panels 30 are a liquid crystal panel 30R, a liquid crystal panel 30G, and a liquid crystal panel 30B. The liquid crystal panel 30R modulates the red component light by rotating the deflection direction of the red component light. An incident-side deflection plate 31R that transmits light having one deflection direction (for example, P deflection) and shields light having another deflection direction (for example, S deflection) to the light incident surface side of the liquid crystal panel 30R. Is provided. On the light exit surface side of the liquid crystal panel 30R, an exit side deflection plate 32R that blocks light having one deflection direction (for example, P deflection) and transmits light having another deflection direction (for example, S deflection). Is provided.

  Similarly, the liquid crystal panel 30G and the liquid crystal panel 30B modulate the green component light and the blue component light by rotating the deflection directions of the green component light and the blue component light, respectively. An incident side deflection plate 31G is provided on the light incident surface side of the liquid crystal panel 30G, and an emission side deflection plate 32G is provided on the light emission surface side of the liquid crystal panel 30G. An incident side deflection plate 31B is provided on the light incident surface side of the liquid crystal panel 30B, and an emission side deflection plate 32B is provided on the light emission surface side of the liquid crystal panel 30B.

  The cross dichroic prism 40 combines light emitted from the liquid crystal panel 30R, the liquid crystal panel 30G, and the liquid crystal panel 30B. The cross dichroic prism 40 emits combined light to the projection lens unit 50 side.

  The projection lens unit 50 projects the combined light (image light) emitted from the cross dichroic prism 40 onto a screen or the like.

(Hue and saturation)
Hereinafter, the hue and saturation according to the first embodiment will be described with reference to the drawings. FIG. 2 is a diagram illustrating a general color reproduction range indicating hue and saturation. In FIG. 2, the point W is a point indicating white. Point R, point G, and point B are points indicating red, green, and blue, respectively.

  As shown in FIG. 2, the hue is represented by an angle formed by the point W and the outer periphery of the color reproduction range. The saturation is the lowest value at the point W, and becomes higher as the distance from the point W increases.

  Incidentally, a video input signal is input from an input device (for example, an imaging device) to the projection display apparatus 100 according to the first embodiment.

  The color reproduction range of the liquid crystal panel 30 depends on the light emitted from each light source unit 10. That is, the higher the color purity of the light emitted from each light source unit 10, the wider the color reproduction range of the liquid crystal panel 30. On the other hand, the color reproduction range of the input device depends on the accuracy of the image sensor provided in the input device.

  In the first embodiment, as shown in FIG. 3, a case is considered in which the color reproduction range (R1, G1, B1) of the liquid crystal panel 30 is wider than the color reproduction range (R2, G2, B2) of the input device.

(Function of projection display device)
Hereinafter, functions of the projection display apparatus according to the first embodiment will be described with reference to the drawings. FIG. 4 is a block diagram illustrating functions of the projection display apparatus 100 (signal processing apparatus 200) according to the first embodiment.

  The signal processing device 200 acquires a video input signal including a red input signal Rin, a green input signal Gin, and a blue input signal Bin. The signal processing device 200 outputs a video output signal including a red output signal Rout, a green output signal Gout, and a blue output signal Bout. The red input signal Rin, the green input signal Gin, and the blue input signal Bin each have a value in a range from the lowest luminance (for example, “0”) to the highest luminance (for example, “255”). Similarly, the red output signal Rout, the green output signal Gout, and the blue output signal Bout each have a value in a range from the lowest luminance (for example, “0”) to the highest luminance (for example, “255”).

  As illustrated in FIG. 4, the signal processing device 200 includes a color coordinate adjustment unit 210, a luminance adjustment unit 220, a ratio control unit 230, and a display element control unit 240.

  The color coordinate adjustment unit 210 performs color coordinate adjustment processing for adjusting the color coordinates of the video input signal according to the difference between the color reproduction range of the liquid crystal panel 30 and the color reproduction range of the input device. The color coordinates in the chromaticity diagram as shown in FIG. 2 indicate a position in a closed curve surrounded by a monochromatic light locus (or spectrum locus) and a pure purple locus, and are defined by saturation and hue. Coordinates. Here, it is assumed that the color reproduction range of the input device is known. Therefore, the color coordinate adjustment unit 210 performs color coordinate adjustment processing according to the color reproduction range of the liquid crystal panel 30. The color coordinate adjustment process is a process of reducing the color coordinate of the video input signal in order to suppress the color coordinate shift caused by the difference in the color reproduction range. Specifically, the color coordinate adjustment process is a process of changing the position in the closed curve described above by adjusting the saturation and the hue.

For example, the color coordinate adjustment unit 210 performs color coordinate adjustment processing according to the following equation (1). Here, RS, GS, and BS are color coordinate adjustment signals corresponding to red, green, and blue, respectively.

  The parameters a to i are constants determined according to the color reproduction range of the liquid crystal panel 30.

  The luminance adjustment unit 220 performs luminance adjustment processing for adjusting the luminance component of the video input signal. The luminance adjustment process is a process for reducing the luminance component of the video input signal in order to suppress the glare of the color with high saturation (purity).

For example, the brightness adjustment unit 220 performs brightness adjustment processing according to the following equation (2). Here, RL, GL, and BL are luminance adjustment signals corresponding to red, green, and blue, respectively.

  The parameter Lum is a constant that determines the amount of decrease in the luminance component of the video input signal. The parameter Lum is a value in the range from the minimum value to 1. The minimum value is a value in the range of 0-1. As the parameter Lum is smaller, the amount of decrease in the luminance component of the video input signal is increased.

  The ratio control unit 230 controls the color coordinate adjustment contribution and the luminance component contribution. The color coordinate adjustment contribution is a contribution that the color coordinate adjustment processing (color coordinate adjustment signal) gives to the video output signal. The luminance component contribution degree is a contribution degree that the luminance adjustment processing (luminance adjustment signal) gives to the video output signal.

  Here, the ratio control unit 230 controls the color coordinate adjustment contribution (1-α) and the luminance component contribution (α) in accordance with the hue and saturation of the video input signal. Α is a value in the range of 0-1.

  Specifically, the ratio control unit 230 acquires the hue and saturation of the video input signal for each pixel. The ratio control unit 230 counts the number of pixels in which the saturation exceeds a predetermined threshold in the first specific hue (here, red hue) or the second specific hue (here, green hue) by the determination counter.

  As illustrated in FIG. 5, the ratio control unit 230 decreases the value of the parameter α until the count value of the determination counter reaches the threshold value Th1. On the other hand, when the count value of the determination counter exceeds the threshold value Th1, the ratio control unit 230 keeps the value of the parameter α at the minimum value (= 0). The parameter α is a value in the range of 0-1.

  The display element control unit 240 acquires a video output signal based on the color coordinates (color coordinate adjustment signal) adjusted by the color coordinate adjustment unit 210 and the luminance component (luminance adjustment signal) adjusted by the luminance adjustment unit 220. The display element control unit 240 controls the ratio between the color coordinate adjustment signal and the luminance adjustment signal in accordance with the parameter α acquired from the ratio control unit 230.

For example, the display element control unit 240 acquires the video output signal according to the following equation (3).

(Operation of projection display device)
Hereinafter, the operation of the projection display apparatus according to the first embodiment will be described with reference to the drawings. FIG. 6 is a flowchart showing functions of the projection display apparatus 100 (signal processing apparatus 200) according to the first embodiment.

  As illustrated in FIG. 6, in step 10, the signal processing device 200 sets one of the plurality of pixels constituting the image (frame) as a control target pixel.

  In step 11, the signal processing device 200 acquires the hue and saturation of the control target pixel according to the video input signal of the control target pixel.

  In step 12, the signal processing apparatus 200 determines whether the hue acquired in step 11 is the first specific hue (here, red hue) or the second specific hue (here, green hue). Determine. When the hue is the first specific hue or the second specific hue, the signal processing apparatus 200 proceeds to the process of step 13. On the other hand, when the hue is not the specific hue, the signal processing device 200 proceeds to the process of step 15.

  In step 13, the signal processing device 200 determines whether or not the saturation acquired in step 11 exceeds a predetermined threshold value. When the saturation exceeds the predetermined threshold, the signal processing device 200 proceeds to the process of step 14. On the other hand, if the saturation does not exceed the predetermined threshold, the signal processing device 200 proceeds to the process of step 15.

  In step 14, the signal processing device 200 counts up the determination counter. Specifically, the signal processing device 200 adds “1” to the count value of the determination counter.

  In step 15, the signal processing device 200 determines whether or not all the pixels constituting the image (frame) have been checked. If all the pixels have been checked, the signal processing device 200 proceeds to the process of step 17. On the other hand, if the signal processing device 200 has not checked all the pixels, the signal processing device 200 proceeds to the process of step 16.

  In step 16, the signal processing device 200 updates the control target pixel. For example, the signal processing device 200 shifts the control target pixel in the horizontal direction or the vertical direction.

  In step 17, the signal processing device 200 determines the control ratio (α) of the color coordinate adjustment contribution and the luminance component contribution. Specifically, as shown in FIG. 5, the signal processing device 200 determines the control ratio (α) according to the count value of the determination counter.

(Function and effect)
In the first embodiment, the ratio control unit 230 has the saturation of the video input signal higher than a predetermined threshold in the first specific hue (for example, red hue) or the second specific hue (for example, green hue). In the case, that is, in the case where the difference between the color coordinates of the image and the actual color coordinates is large, the color coordinate adjustment contribution is increased and the luminance component contribution is decreased.

  Therefore, in the case where the difference between the color coordinates of the image and the actual color coordinates is large, the difference between the color coordinates of the image and the actual color coordinates can be suppressed.

  On the other hand, the ratio control unit 230 has a case where the saturation of the video input signal is lower than a predetermined threshold in the first specific hue (for example, red hue) or the second specific hue (for example, green hue), that is, In the case where the difference between the color coordinates of the image and the actual color coordinates is small, the color coordinate adjustment contribution is decreased and the luminance component contribution is increased.

  Therefore, in the case where the difference between the color coordinates of the image and the actual color coordinates is small, the color reproduction range of the liquid crystal panel 30 can be used effectively.

[Second Embodiment]
Hereinafter, the second embodiment will be described with reference to the drawings. In the following, differences between the first embodiment and the second embodiment described above will be mainly described.

  Specifically, in the first embodiment described above, the parameter Lum used in the brightness adjustment process is a constant. On the other hand, in the second embodiment, the parameter Lum used in the brightness adjustment process is determined according to the average brightness of a plurality of pixels constituting the image (frame).

(Function of projection display device)
Hereinafter, functions of the projection display apparatus according to the second embodiment will be described with reference to the drawings. FIG. 7 is a block diagram illustrating functions of the projection display apparatus 100 (signal processing apparatus 200) according to the second embodiment. In FIG. 7, the same reference numerals are given to the same components as those in FIG.

  As illustrated in FIG. 7, the signal processing device 200 includes an acquisition unit 250 in addition to the configuration illustrated in FIG. 4. The acquisition unit 250 acquires the average luminance of a plurality of pixels constituting an image (frame) according to the video input signal.

(Parameter Lum)
Hereinafter, the parameter Lum according to the second embodiment will be described with reference to the drawings. FIG. 8 is a diagram illustrating a parameter Lum according to the second embodiment.

  As illustrated in FIG. 8, the luminance adjustment unit 220 described above determines the parameter Lum according to the average luminance of a plurality of pixels that form an image (frame). Specifically, the brightness adjustment unit 220 determines the parameter Lum to be a smaller value as the average brightness is higher. That is, the luminance adjustment unit 220 increases the amount of decrease in the luminance component of the video input signal as the average luminance is higher.

  The parameter Lum is a value in the range of the minimum value to 1 as in the first embodiment. The minimum value is a value in the range of 0-1.

(Function and effect)
In the second embodiment, the luminance adjustment unit 220 determines the parameter Lum to a smaller value as the average luminance is higher. That is, in a high-brightness image that tends to cause glare, the amount of decrease in the luminance component of the video input signal is increased. On the other hand, in a low-brightness image in which glare is unlikely to occur, the amount of decrease in the luminance component of the video input signal is reduced. Therefore, it is possible to suppress glare while improving the luminance to some extent.

[Third Embodiment]
Hereinafter, a third embodiment will be described with reference to the drawings. In the following, differences between the first embodiment and the third embodiment described above will be mainly described.

Specifically, the luminance component contribution degree control ratio (α) according to the first embodiment described above is determined according to the count value of the determination counter. On the other hand, the luminance component contribution ratio control ratio (β) according to the third embodiment is set to the hue gain GAIN _{H (m, n)} and the saturation gain GAIN _{S (m, n)} acquired for each pixel. It is determined accordingly.

(Function of projection display device)
Hereinafter, functions of the projection display apparatus according to the third embodiment will be described with reference to the drawings. FIG. 9 is a block diagram illustrating functions of the projection display apparatus 100 (signal processing apparatus 200) according to the third embodiment. In FIG. 9, the same components as those in FIG. 4 are denoted by the same reference numerals.

  As illustrated in FIG. 9, the signal processing device 200 includes an acquisition unit 250 in addition to the configuration illustrated in FIG. 4.

  The acquisition unit 250 acquires various types of information according to the video input signal. Specifically, the acquisition unit 250 acquires (1) the hue of the pixel (m, n) constituting the image (frame), and (2) the saturation of the pixel (m, n) constituting the image (frame). To do.

Here, the above-described ratio control unit 230 acquires the parameter α _{(m, n)} corresponding to the pixel (m, n) according to the hue and saturation.

Specifically, as shown in FIG. 10, the ratio control unit 230 acquires a hue gain (GAIN _{H (m, n)} ) according to the hue of the pixel (m, n). Here, the first specific hue (here, red hue) has a predetermined hue width ω1 including the first target hue TG1. The second specific hue (here, green hue) has a predetermined hue width ω2 including the second target hue TG2. The hue gain (GAIN _{H (m, n)} ) becomes higher as the hue is closer to the target hue TG1 or the target hue TG2. The hue gain (GAIN _{H (m, n)} ) is a value in the range from the minimum value (0 to 1) to 1.

As illustrated in FIG. 11, the ratio control unit 230 acquires a saturation gain (GAIN _{S (m, n)} ) according to the saturation of the pixel (m, n). The saturation gain (GAIN _{S (m, n)} ) increases as the saturation increases until the saturation reaches the threshold Th2. On the other hand, the saturation gain (GAIN _{S (m, n)} ) is maintained at the maximum value (= 1) when the saturation exceeds the threshold Th2. Note that the saturation gain (GAIN _{S (m, n)} ) is a value in the range of 0-1.

The ratio control unit 230 sets the parameter α _{(m, n)} corresponding to the pixel (m, n) according to the hue gain (GAIN _{H (m, n)} ) and the saturation gain (GAIN _{S (m, n) ).} To get. For example, the ratio control unit 230 acquires the parameter α _{(m, n)} corresponding to the pixel (m, n) according to the following equation (4).

Subsequently, the ratio control unit 230 obtains an added value (TOTAL _α ) by adding the parameters α _{(m, n)} of all the pixels (m, n) constituting the image (frame). That is, the ratio control unit 230 acquires the added value (TOTAL _α ) according to the following equation (5).

As illustrated in FIG. 12, the ratio control unit 230 acquires the parameter β for each image (frame) according to the addition value (TOTAL _α ). The parameter β decreases as the added value (TOTAL _α ) increases. On the other hand, the parameter β is kept at the minimum value (= 0) when the saturation exceeds the threshold Th3. The parameter β is a value in the range of 0-1.

  Therefore, the ratio control unit 230 increases the color coordinate adjustment contribution and decreases the luminance component contribution as the hue is closer to the first target hue TG1 or the second target hue TG2. In addition, the ratio control unit 230 increases the color coordinate adjustment contribution and decreases the luminance component contribution as the saturation is higher.

  The display element control unit 240 controls the ratio between the color coordinate adjustment signal and the luminance adjustment signal for the image according to the parameter β acquired from the ratio control unit 230.

For example, the display element control unit 240 acquires the video output signal according to the following equation (6).

(Function and effect)
In the third embodiment, the ratio control unit 230 increases the color coordinate adjustment contribution and decreases the luminance component contribution as the hue is closer to the first target hue TG1 or the second target hue TG2. Therefore, the difference between the color coordinates of the image and the actual color coordinates can be further suppressed for pixels having a hue close to the first target hue TG1 or the second target hue TG2.

  In addition, the ratio control unit 230 increases the color coordinate adjustment contribution and decreases the luminance component contribution as the saturation is higher. Therefore, the difference between the color coordinates of the image and the actual color coordinates can be further suppressed for pixels with high saturation (purity).

[Fourth Embodiment]
Hereinafter, a fourth embodiment will be described with reference to the drawings. In the following, differences between the first embodiment and the fourth embodiment described above will be mainly described.

Specifically, the luminance component contribution degree control ratio (α) according to the first embodiment described above is determined according to the count value of the determination counter. In contrast, the luminance component luminance control ratio (γ) according to the fourth embodiment is determined for each image according to the hue distribution width RANGE _H and the saturation distribution width RANGE _S acquired for each image.

(Function of projection display device)
Hereinafter, functions of the projection display apparatus according to the fourth embodiment will be described with reference to the drawings. FIG. 13 is a block diagram illustrating functions of the projection display apparatus 100 (signal processing apparatus 200) according to the fourth embodiment. In FIG. 13, the same reference numerals are given to the same components as those in FIG.

  As illustrated in FIG. 13, the signal processing device 200 includes an acquisition unit 250 in addition to the configuration illustrated in FIG. 4.

  The acquisition unit 250 acquires various types of information for each pixel (m, n) according to the video input signal. Specifically, the acquisition unit 250 acquires (1) the hue of the pixel (m, n) constituting the image (frame), and (2) the saturation of the pixel (m, n) constituting the image (frame). To do.

Here, the ratio control unit 230 described above includes the hue distribution width RANGE _H and the saturation distribution width RANGE _S in the first specific hue (here, red hue) and the second specific hue (here, green hue). Accordingly, the parameter γ is acquired for each image (frame). The hue distribution width RANGE _H is a width in which the hues acquired by the acquisition unit 250 in the first specific hue and the second specific hue are distributed. The saturation distribution width RANGE _S is a width in which the saturation acquired by the acquisition unit 250 in the first specific hue and the second specific hue is distributed.

For example, as illustrated in FIG. 14, the ratio control unit 230 can acquire the hue distribution width RANGE _H by forming a histogram of the hue frequencies acquired by the acquisition unit 250. The hue distribution width RANGE _H is the sum of the first specific hue distribution width RANGE _HR and the second specific hue distribution width RANGE _HG .

For example, as illustrated in FIG. 15, the ratio control unit 230 can acquire the saturation distribution width RANGE _S by histogramming the saturation frequency acquired by the acquisition unit 250.

Subsequently, as illustrated in FIG. 16, the ratio control unit 230 acquires the hue gain GAIN _H according to the hue distribution width RANGE _H. The hue gain GAIN _H increases as the hue distribution width RANGE _H increases until the hue distribution width RANGE _H reaches the threshold Th4. On the other hand, the hue gain GAIN _H is maintained at the maximum value (= 1) when the hue distribution width RANGE _H exceeds the threshold Th4. The hue gain GAIN _H is a value in the range of 0 to 1.

As illustrated in FIG. 17, the ratio control unit 230 acquires the saturation gain GAIN _S according to the saturation distribution width RANGE _S. The saturation gain GAIN _S increases as the saturation distribution width RANGE _S increases until the saturation distribution width RANGE _S reaches the threshold Th5. On the other hand, the saturation gain GAIN _S is maintained at the maximum value (= 1) when the saturation distribution width RANGE _S exceeds the threshold Th5. Incidentally, the saturation gain GAIN _S is a value in the range of 0-1.

Next, the ratio control unit 230 acquires a parameter γ corresponding to an image (frame) according to the hue gain GAIN _H and the saturation gain GAIN _S. For example, the ratio control unit 230 acquires the parameter γ corresponding to the image according to the following equation (7).

Therefore, the ratio control unit 230 increases the luminance component contribution and decreases the color coordinate adjustment contribution as the hue distribution width RANGE _H is wider. The ratio control unit 230 increases the luminance component contribution and decreases the color coordinate adjustment contribution as the saturation distribution width RANGE _S is wider.

  The display element control unit 240 controls the ratio between the color coordinate adjustment signal and the luminance adjustment signal for the image (frame) according to the parameter γ acquired from the ratio control unit 230.

For example, the display element control unit 240 acquires the video output signal according to the following equation (8).

(Function and effect)
In the fourth embodiment, the ratio control unit 230 acquires a parameter γ corresponding to an image (frame) according to the hue distribution width and the saturation distribution width.

Specifically, the ratio control unit 230 increases the luminance component contribution degree as the hue distribution width RANGE _H in the first specific hue (here, red hue) and the second specific hue (here, green hue) is wider. And the color coordinate adjustment contribution is reduced. Therefore, it is possible to suppress a reduction in the hue difference of each pixel in the first specific hue and the second specific hue. Therefore, occurrence of color gradation collapse in an image (frame) can be suppressed.

In addition, the ratio control unit 230 increases the luminance component contribution degree as the saturation distribution width RANGE _S in the first specific hue (here, red hue) and the second specific hue (here, green hue) is wider. And the color coordinate adjustment contribution is reduced. Therefore, it is possible to suppress the reduction in the saturation difference of each pixel in the first specific hue and the second specific hue. Therefore, it is possible to suppress the occurrence of the color gradation collapse in the image.

[Fifth Embodiment]
Hereinafter, a fifth embodiment will be described with reference to the drawings. In the following, differences between the above-described first embodiment and the fifth embodiment will be mainly described.

Specifically, the luminance component contribution degree control ratio (α) according to the first embodiment described above is determined according to the count value of the determination counter. On the other hand, the luminance component contribution control ratio (α _{(m, n)} ) according to the fifth embodiment includes the luminance gain (GAIN _{L (m, n)} ) and hue gain (GAIN) acquired for each pixel. _{H (m, n)} ) and saturation gain (GAINS _{(m, n)} ) are determined for each pixel.

(Function of projection display device)
The function of the projection display apparatus according to the fifth embodiment will be described below with reference to the drawings. FIG. 18 is a block diagram illustrating functions of the projection display apparatus 100 (signal processing apparatus 200) according to the fifth embodiment. In FIG. 18, the same components as those in FIG. 4 are denoted by the same reference numerals.

  As illustrated in FIG. 18, the signal processing device 200 includes an acquisition unit 250 in addition to the configuration illustrated in FIG. 4.

  The acquisition unit 250 acquires various types of information for each pixel (m, n) according to the video input signal. Specifically, the acquisition unit 250 configures (1) luminance of pixels (m, n) constituting an image (frame), (2) hue constituting an image (frame), and (3) image (frame). The saturation of the pixel (m, n) to be acquired is acquired.

Here, the above-described ratio control unit 230 acquires the parameter α _{(m, n)} corresponding to the pixel (m, n) according to the luminance, hue, and saturation.

Specifically, the ratio control unit 230 acquires a luminance gain (GAIN _{L (m, n)} ) according to the luminance of the pixel (m, n) as shown in FIG. The luminance gain (GAIN _{L (m, n)} ) becomes a lower value as the luminance is higher. When the luminance exceeds the threshold Th6, the ratio control unit 230 keeps the value of the luminance gain (GAIN _{L (m, n)} ) at the minimum value. The luminance gain (GAIN _{L (m, n)} ) is a value in the range from the minimum value to 1. The minimum value is a value in the range of 0-1.

As shown in FIG. 20, the ratio control unit 230 acquires a hue gain (GAIN _{H (m, n)} ) according to the hue of the pixel (m, n). Here, the first specific hue (here, red hue) has a predetermined hue width ω1 including the first target hue TG1. The second specific hue (here, green hue) has a predetermined hue width ω2 including the second target hue TG2. The hue gain (GAIN _{H (m, n)} ) becomes a lower value as the hue is closer to the target hue TG1 or the target hue TG2. The hue gain (GAIN _{H (m, n)} ) is a minimum value when the hue is the target hue TG1 or the target hue TG2. The minimum value is a value in the range of 0-1.

As illustrated in FIG. 21, the ratio control unit 230 acquires a saturation gain (GAIN _{S (m, n)} ) according to the saturation of the pixel (m, n). The saturation gain (GAIN _{S (m, n)} ) becomes a lower value as the saturation is higher until the saturation reaches the threshold Th7. On the other hand, the saturation gain (GAIN _{S (m, n)} ) is kept at the minimum value when the saturation exceeds the threshold Th7. The minimum value is a value in the range of 0-1.

Subsequently, the ratio control unit 230 generates pixels according to the luminance gain (GAIN _{L (m, n)} ), hue gain (GAIN _{H (m, n)} ), and saturation gain (GAIN _{S (m, n)} ). A parameter α _{(m, n)} corresponding to _{(m, n)} is acquired. For example, the ratio control unit 230 acquires the parameter α _{(m, n)} corresponding to the pixel (m, n) according to the following equation (9).

  Thus, the ratio controller 230 increases the color coordinate adjustment contribution and decreases the luminance component contribution as the luminance is higher. The ratio control unit 230 increases the color coordinate adjustment contribution and decreases the luminance component contribution as the hue is closer to the target hue TG1 or the target hue TG1. In addition, the ratio control unit 230 increases the color coordinate adjustment contribution and decreases the luminance component contribution as the saturation is higher.

The display element control unit 240 controls the ratio of the color coordinate adjustment signal and the luminance adjustment signal for each pixel (m, n) according to the parameter α _{(m, n)} acquired from the ratio control unit 230.

(Operation of projection display device)
The operation of the projection display apparatus according to the fifth embodiment will be described below with reference to the drawings. FIG. 22 is a flowchart showing functions of the projection display apparatus 100 (signal processing apparatus 200) according to the fifth embodiment.

  As shown in FIG. 22, in step 20, the signal processing device 200 acquires the luminance of the pixel (m, n) constituting the image (frame) according to the video input signal.

In step 21, the signal processing device 200 acquires a luminance gain (GAIN _{L (m, n)} ) according to the luminance acquired in step 20.

  In step 22, the signal processing device 200 acquires the hue of the pixel (m, n) constituting the image (frame) according to the video input signal.

In step 23, the signal processing apparatus 200 acquires a hue gain (GAIN _{H (m, n)} ) according to the hue acquired in step 22.

  In step 24, the signal processing device 200 acquires the saturation of the pixel (m, n) constituting the image (frame) according to the video input signal.

In step 25, the signal processing device 200 acquires a saturation gain (GAIN _{S (m, n)} ) according to the saturation acquired in step 24.

In step 26, the signal processing device 200 determines a control ratio (α _{(m, n)} ) of the color coordinate adjustment contribution and the luminance component contribution. Specifically, the signal processing apparatus 200 determines a parameter α _{(m, n)} corresponding to the pixel (m, n) according to each gain acquired in step 21, step 23, and step 25. It should be noted that the signal processing device 200 performs the processing from step 20 to step 26 for all the pixels constituting the image (frame).

(Function and effect)
In the fifth embodiment, the ratio control unit 230 acquires the parameter α _{(m, n)} for each pixel constituting the image (frame) according to the luminance, hue, and saturation. The display element control unit 240 controls the ratio between the color coordinate adjustment signal and the luminance adjustment signal for each pixel.

  Therefore, it is possible to achieve both the suppression of glare in the first specific hue (for example, red hue) and the second specific hue (for example, blue hue) and the effective use of the color reproduction range of the liquid crystal panel 30 as the entire image. Can do.

[Other Embodiments]
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

Although not specifically mentioned in the above-described embodiment, the control ratio of the luminance component contribution degree may be determined based on the parameter β according to the third embodiment and the parameter α _{(m, n)} according to the fifth embodiment. Good. Specifically, a multiplication value obtained by multiplying both is used as the control ratio of the luminance component contribution. Thus, even when the first specific hue (here, red hue) and the second specific hue (here, blue hue) are present in only a small part of the image (frame), the first specific hue and Suppression of glare in the second specific hue and effective use of the color reproduction range of the liquid crystal panel 30 can be achieved.

  In the second embodiment described above, the average brightness value is used in the acquisition of the parameter Lum, but the present invention is not limited to this. In the acquisition of the parameter Lum, the total luminance value of each pixel constituting the image (frame) may be used.

In the third embodiment described above, the parameter β is determined by the hue gain GAIN _H and the saturation gain GAIN _S , but is not limited thereto. The parameter β may be determined by either the hue gain (GAIN _{H (m, n)} ) or the saturation gain (GAIN _{S (m, n)} ).

In the fourth embodiment described above, the parameter γ is determined by the hue distribution width RANGE _H and the saturation distribution width RANGE _S , but is not limited thereto. The parameter γ may be determined by either the hue distribution width RANGE _H or the saturation distribution width RANGE _S.

In the fifth embodiment described above, the luminance gain (GAIN _{L (m, n)} ) is used in the acquisition of the parameter α _{(m, n)} , but the present invention is not limited to this. In the acquisition of the parameter α _{(m, n)} , a total value or an average value of the luminance of each pixel constituting the image (frame) may be used.

In the fifth embodiment described above, the parameter α _{(m, n)} is determined by the luminance gain (GAINL), the hue gain (GAIN _{H (m, n)} ), and the saturation gain (GAIN _{S (m, n)} ). However, the present invention is not limited to this. The parameter α _{(m, n)} may be determined by any one of luminance gain (GAINL), hue gain (GAIN _{H (m, n)} ), and saturation gain (GAIN _{S (m, n)} ). For example, the parameter α (m, n) may be determined only by the luminance gain (GAINL). The parameter α _{(m, n)} may be determined only by the hue gain (GAIN _{H (m, n)} ). The parameter α _{(m, n)} may be determined only by the saturation gain (GAIN _{S (m, n)} ).

  Although not particularly mentioned in the above-described embodiment, in the case where the first specific hue or the second specific hue is a blue hue, in the case where the difference between the color coordinate of the image and the actual color coordinate is large, the luminance The component contribution may be increased and the color coordinate adjustment contribution may be decreased.

  In the embodiment described above, the liquid crystal panel 30 is used as the display device, but the present invention is not limited to this. As the display device, LCOS (Liquid Crystal on Silicon), DMD (Digital Micromirror Device), or the like may be used.

  In the embodiment described above, a solid light source is used as the light source, but the present invention is not limited to this. A UHP lamp that emits white light may be used as the light source.

It is a figure which shows the structure of the projection type video display apparatus concerning 1st Embodiment. It is a figure which shows the general color reproduction range which shows a hue and saturation. It is a figure which shows the color reproduction range of the liquid crystal panel 30 which concerns on 1st Embodiment. It is a block diagram which shows the structure of the signal processing apparatus 200 which concerns on 1st Embodiment. It is a figure which shows parameter (alpha) based on 1st Embodiment. It is a flowchart which shows operation | movement of the signal processing apparatus 200 which concerns on 1st Embodiment. It is a block diagram which shows the structure of the signal processing apparatus 200 which concerns on 2nd Embodiment. It is a figure showing parameter Lum concerning a 2nd embodiment. It is a block diagram which shows the structure of the signal processing apparatus 200 which concerns on 3rd Embodiment. It is a figure which shows the hue gain (GAINH _{(m, n)} ) concerning 3rd Embodiment. It is a figure which shows the saturation gain (GAINS _{(m, n)} ) which concerns on 3rd Embodiment. It is a figure which shows parameter (beta) concerning 3rd Embodiment. It is a block diagram which shows the structure of the signal processing apparatus 200 which concerns on 4th Embodiment. It is a figure which shows the hue distribution width RANGE _H which concerns on 4th Embodiment. It is a figure which shows the saturation distribution width RANGE _S which concerns on 4th Embodiment. It is a diagram illustrating a hue gain GAIN _H according to a fourth embodiment. Is a diagram illustrating a saturation gain GAIN _S according to the fourth embodiment. It is a block diagram which shows the structure of the signal processing apparatus 200 which concerns on 5th Embodiment. It is a figure which shows the luminance gain GAIN _{L (m, n)} which concerns on 5th Embodiment. It is a figure which shows the saturation gain GAINH _{(m, n)} which concerns on 5th Embodiment. It is a figure which shows the saturation gain GAIN _{S (m, n)} which concerns on 5th Embodiment. It is a flowchart which shows operation | movement of the signal processing apparatus 200 which concerns on 5th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Light source unit, 20 ... Fly eye lens unit, 30 ... Liquid crystal panel, 40 ... Cross dichroic prism, 50 ... Projection lens unit, 100 ... Projection type video display apparatus, 200 ... Signal processing device, 210 ... Color coordinate adjustment unit, 220 ... Brightness adjustment unit, 230 ... Ratio control unit, 240 ... Display element control unit, 250 ... Acquisition unit

Claims (8)

A signal processing device that converts a video input signal into a video output signal and outputs the video output signal to a display device,
A color coordinate adjustment unit that performs a color coordinate adjustment process for adjusting a color coordinate of the video input signal according to a color reproduction range of the display device;
A luminance adjustment unit for performing luminance adjustment processing for adjusting a luminance component of the video input signal;
An output signal generation unit configured to generate the video output signal based on the color coordinates adjusted by the color coordinate adjustment process and the luminance component adjusted by the luminance adjustment process;
A control unit that controls a color coordinate adjustment contribution degree that the color coordinate adjustment process gives to the video output signal and a luminance component contribution degree that the luminance adjustment process gives to the video output signal according to the saturation of the video input signal; With
The control unit increases the color coordinate adjustment contribution and decreases the luminance component contribution as the saturation of the video input signal is higher in the first specific hue or the second specific hue. Signal processing device. An acquisition unit for acquiring the luminance of the image according to the video input signal;
The signal processing apparatus according to claim 1, wherein the control unit increases a decrease amount of a luminance component of the video input signal in the luminance adjustment process as the luminance acquired by the acquisition unit is higher. According to the video input signal, further comprising an acquisition unit for acquiring a hue for each pixel constituting the image,
The first specific hue has a first hue width including a first target hue,
The second specific hue has a second hue width including a second target hue,
The controller is
The closer the hue acquired by the acquisition unit is to the first target hue, the higher the color coordinate adjustment contribution and the lower the luminance component contribution,
2. The signal processing according to claim 1, wherein the color coordinate adjustment contribution is increased and the luminance component contribution is decreased as the hue acquired by the acquisition unit is closer to the second target hue. apparatus. According to the video input signal, further comprising an acquisition unit for acquiring a hue for each pixel constituting the image,
The controller is
As the first hue distribution width, which is the width in which the hue acquired by the acquisition unit is distributed in the first specific hue, is increased, the luminance component contribution is increased and the color coordinate adjustment contribution is decreased,
In the second specific hue, the luminance component contribution is increased and the color coordinate adjustment contribution is decreased as the second hue distribution width, which is a width in which the hue acquired by the acquisition unit is distributed, is wider. The signal processing device according to claim 1, wherein: According to the video input signal, further comprising an acquisition unit for acquiring saturation for each pixel constituting the image,
The signal processing according to claim 1, wherein the control unit increases the luminance component contribution degree and decreases the color coordinate adjustment contribution degree as the saturation acquired by the acquisition unit is higher. apparatus. According to the video input signal, further comprising an acquisition unit for acquiring saturation for each pixel constituting the image,
The controller is
As the first saturation distribution width, which is the width in which the saturation acquired by the acquisition unit in the first specific hue is widened, the luminance component contribution is increased and the color coordinate adjustment contribution is decreased. ,
As the second saturation distribution width, which is the width over which the saturation acquired by the acquisition unit in the second specific hue is distributed, the luminance component contribution is increased and the color coordinate adjustment contribution is decreased. The signal processing apparatus according to claim 1.   The signal processing device according to claim 1, wherein the control unit controls the luminance component contribution degree and the color coordinate adjustment contribution degree for each pixel.   A signal processing device according to claim 1, a display device that displays an image in accordance with a video output signal output from the signal processing device, and a projection unit that projects an image displayed by the display device. A projection display apparatus characterized by the above.

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