JP6494195B2 - Image display apparatus, image display apparatus control method, and program - Google Patents

Description

  The present invention relates to an image display device, an image display device control method, and a program.

Conventional techniques relating to an image display device such as a liquid crystal display device are disclosed in Patent Documents 1 to 3, for example.
Patent Documents 1 and 3 disclose backlights having a plurality of light sources. In the technologies disclosed in Patent Documents 1 and 3, the plurality of light sources are respectively arranged in the plurality of divided regions constituting the region of the screen.
In the technique disclosed in Patent Document 1, the light emission luminances of a plurality of light sources are individually controlled based on the feature amount of the input image. Such control is called “local dimming control”. By performing local dimming control, the dynamic range of the display image (image displayed on the screen) can be expanded, and the contrast of the display image can be improved. By performing local dimming control, the above effect can be obtained even when an image with a large change in luminance value (luminance gradient) in the screen direction is displayed.
Patent Document 2 discloses a technique for stopping processing for controlling the light emission luminance of a backlight based on a feature amount of an input image during multi-image display in which a plurality of images are displayed side by side.
In the technique disclosed in Patent Document 3, the difference in light emission luminance of the light source between two adjacent divided areas is limited to an allowable value or less. Thereby, the malfunction that the boundary line between two division areas adjacent to each other is visually recognized can be reduced.

  However, if the techniques of Patent Documents 1 and 2 are combined, local dimming control is stopped during multi-image display. Therefore, if the techniques of Patent Documents 1 and 2 are combined, the effect of expanding the dynamic range of the display image and the effect of improving the contrast of the display image cannot be obtained during multi-image display. In other words, if the techniques of Patent Documents 1 and 2 are combined, the dynamic range and contrast of the display image will be reduced during multi-image display.

In addition, during multi-image display, light from one light source may be applied to a plurality of image display areas (a plurality of areas where a plurality of images are respectively displayed). Hereinafter, a light source that irradiates a plurality of image display areas with light is referred to as a “near boundary light source”.
In the conventional local dimming control, the light emission luminance of each light source is controlled according to the feature amount of the image displayed in the divided area where the light source is arranged. Since one image is displayed in the divided area where the light sources other than the light sources near the boundary are arranged, the light emission luminance of the light sources other than the light sources near the boundary is controlled according to the feature amount of the one image. Since one or more images are displayed in the divided area where the light source near the boundary is arranged, the emission luminance of the light source near the boundary is controlled according to the feature amount of the one or more images.

Therefore, if the above-described conventional local dimming control is performed during multi-image display, the image quality of the display image may be deteriorated. Specifically, an image I2 (for example, a moving image) in which the emission luminance of the near-boundary light source LS that irradiates light to a plurality of image display areas including the image display area of the image I1 (for example, a still image) is unrelated to the image I1. May vary according to the variation of the feature quantity of the image. When such a variation in emission luminance occurs, an unexpected variation in display luminance (brightness on the screen) occurs at the edge of the image I1 (region irradiated with light from the light source LS near the boundary). End up.
Note that the above-described image quality degradation can also occur when the emission color is controlled by local dimming control.

JP 2002-99250 A JP 2007-241250 A JP 2008-122713 A

  The present invention provides a technique capable of suppressing deterioration in display image quality caused by performing conventional local dimming control during multi-image display while suppressing a decrease in dynamic range and contrast of the display image. Objective.

The first aspect of the present invention is:
A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
Control means for controlling a light emission state that is at least one of a light emission luminance and a light emission color of each light source based on a feature amount of the display image in a region of the screen corresponding to each light source;
With
When the display image is an image arranged in a region where the first image and the second image are different from each other,
A change in the light emission state of the target light source corresponding to a region including a boundary between the first image and the second image and a region in the vicinity thereof in the screen among the plurality of light sources,
In the image display device that is controlled so as to be suppressed compared to a change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources,
First acquisition means for acquiring a first feature amount that is a feature amount of the first image;
Second acquisition means for acquiring a second feature amount that is a feature amount of the second image;
Further comprising
The control means is configured such that a change in a light emission state of the target light source due to a change in the display image is significantly suppressed as a difference between the first feature amount and the second feature amount is larger than that of the non-target light source. To control the light emission state of each light source,
An image display device characterized by the above.
The second aspect of the present invention is:
A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
Control means for controlling a light emission state that is at least one of a light emission luminance and a light emission color of each light source based on a feature amount of the display image in a region of the screen corresponding to each light source;
With
When the display image is an image arranged in a region where the first image and the second image are different from each other,
A change in the light emission state of the target light source corresponding to a region including a boundary between the first image and the second image and a region in the vicinity thereof in the screen among the plurality of light sources,
In the image display device that is controlled so as to be suppressed compared to a change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources,
First detection means for detecting a scene change of the first image when the first image is a moving image;
Second detection means for detecting a scene change in the second image when the second image is a moving image;
Further comprising
When the first image and the second image are moving images and the scene of the first image and the scene of the second image are switched simultaneously, the control means sets the target light source as the non-target. Consider the light source and control the light emission state of each light source.
An image display device characterized by the above.

The third aspect of the present invention is:
A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
A method for controlling an image display device comprising:
A control step of controlling a light emission state that is at least one of a light emission luminance and a light emission color of each light source based on a feature amount of the display image in a region of the screen corresponding to each light source;
In the control step, when the display image is an image arranged in a region where the first image and the second image are different from each other,
A change in the light emission state of the target light source corresponding to a region including a boundary between the first image and the second image and a region in the vicinity thereof in the screen among the plurality of light sources,
In the control method of the image display device that controls to be suppressed as compared with the change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources,
A first acquisition step of acquiring a first feature amount that is a feature amount of the first image;
A second acquisition step of acquiring a second feature amount that is a feature amount of the second image;
Further comprising
In the control step, the change in the light emission state of the target light source due to the change in the display image is more suppressed as the difference between the first feature amount and the second feature amount is larger than that of the non-target light source. To control the light emission state of each light source,
This is a method for controlling an image display device.
The fourth aspect of the present invention is:
A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
A method for controlling an image display device comprising:
A control step of controlling a light emission state that is at least one of the light emission luminance and the light emission color of each light source based on the feature amount of the display image in the area of the screen corresponding to each light source.
Have
In the control step, when the display image is an image arranged in a region where the first image and the second image are different from each other,
A change in the light emission state of the target light source corresponding to a region including a boundary between the first image and the second image and a region in the vicinity thereof in the screen among the plurality of light sources,
In the control method of the image display device that controls to be suppressed as compared with the change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources
A first detection step of detecting a scene change of the first image when the first image is a moving image;
A second detection step of detecting a scene change of the second image when the second image is a moving image;
Further comprising
In the control step, when the first image and the second image are moving images, and the scene of the first image and the scene of the second image are switched simultaneously, the target light source is set to the non-target. Consider the light source and control the light emission state of each light source.
This is a method for controlling an image display device.

According to a fifth aspect of the present invention, there is provided a program for causing a computer to execute each step of the above-described image display apparatus control method.

  ADVANTAGE OF THE INVENTION According to this invention, the image quality degradation of the display image which arises by performing the conventional local dimming control at the time of multi-image display can be suppressed, suppressing the dynamic range of a display image, and the fall of contrast.

FIG. 1 is a block diagram illustrating an example of a functional configuration of an image display device according to a first embodiment. The figure which shows an example of the 1st correspondence and 2nd correspondence which concern on Example 1. The figure which shows an example of the detection method of the light source near a boundary based on Example 1. FIG. FIG. 10 is a diagram illustrating an example of the operation of the image display apparatus according to the first embodiment. FIG. 10 is a diagram illustrating an example of the operation of the image display apparatus according to the first embodiment. FIG. 7 is a diagram illustrating an example of an operation of the image display apparatus according to the first embodiment and a conventional example. FIG. 7 is a block diagram illustrating an example of a functional configuration of an image display apparatus according to a second embodiment. FIG. 6 is a diagram illustrating an example of an operation of an image display apparatus according to a second embodiment and a conventional example. FIG. 9 is a block diagram illustrating an example of a functional configuration of an image display apparatus according to a third embodiment. FIG. 9 is a block diagram illustrating an example of a functional configuration of an image display apparatus according to a third embodiment. FIG. 10 is a diagram illustrating an example of a display image according to a third embodiment and a conventional example. The figure which shows an example of the 1st correspondence and 2nd correspondence which concern on Example 4. FIG. 10 is a diagram illustrating an example of a display image according to a fifth embodiment and a conventional example. The figure which shows an example of the 4th correspondence and 5th correspondence which concern on Example 6. FIG. 10 is a diagram illustrating an example of an operation of an image display apparatus according to a sixth embodiment and a conventional example. The figure which shows an example of the display image which concerns on the modification of an Example. The figure which shows an example of operation | movement of the conventional image display apparatus.

<Example 1>
Hereinafter, an image display apparatus and a control method thereof according to Embodiment 1 of the present invention will be described with reference to the drawings.
In this embodiment, an example in which the image display device is a transmissive liquid crystal display device will be described. However, the image display device is not limited to a transmissive liquid crystal display device. The image display device may be an image display device that displays an image on a screen by modulating light from the light emitting unit. For example, the image display device may be a reflective liquid crystal display device. In addition, the image display device may be a MEMS shutter type display using a MEMS (Micro Electro Mechanical System) shutter instead of the liquid crystal element.

FIG. 1 is a block diagram illustrating an example of a functional configuration of the image display apparatus according to the present embodiment.
The image display apparatus according to the present embodiment displays an image based on display target image data. Display target image data is image data representing a display target image. A plurality of image data (input image data) can be input to the image display apparatus according to the present embodiment. Input image data is image data representing an input image. The image display apparatus according to the present embodiment can generate composite image data representing a composite image in which a plurality of images are arranged as display target image data.
Hereinafter, an example will be described in which a plurality of input image data is input to the image display device, and composite image data representing a composite image in which the plurality of input images are arranged is generated.

The backlight module 108 is a light emitting unit having a plurality of light sources respectively arranged in a plurality of divided areas constituting a screen area. One light source has one or more light emitting elements. As the light emitting element, a light emitting diode, an organic EL element, a cold cathode tube, or the like can be used. The light emission states of the plurality of light sources can be individually controlled. The emission state is emission luminance, emission color, or both. In this embodiment, an example in which the light emission state is light emission luminance will be described.
One light source may include a plurality of light emitting elements having the same emission color, or may include a plurality of light emitting elements having different emission colors. In the case where one light source has a plurality of light-emitting elements, the emission color of the light source can be controlled by controlling the ratio of the light emission luminance of the plurality of light-emitting elements.

  The liquid crystal panel 109 is a display unit that displays an image on a screen by transmitting (modulating) light from the backlight module 108.

The display area setting unit 101 sets an area (image display area) in which each input image is displayed. The image display area is set according to a user operation, for example. Then, the display area setting unit 101 generates display area information representing each image display area and boundary position information representing the position of the boundary between the image display areas. The display area setting unit 101 outputs display area information to the combining unit 102 and outputs boundary position information to the backlight control unit 106.
The display area information and the boundary position information may be recorded in advance in a storage unit (memory) (not shown).

  The synthesizing unit 102 generates display target image data based on the plurality of input image data and the display area information output from the display area setting unit 101. Specifically, the composition unit 102 generates composite image data representing a composite image in which a plurality of input images are respectively arranged in a plurality of image display regions represented by display region information as display target image data. The composition unit 102 outputs the composite image data (display target image data) to the image correction unit 107.

Note that the synthesis unit 102 performs image processing for transforming the input image on the input image data as necessary. Image processing for transforming the input image includes, for example, enlargement processing for enlarging the input image, reduction processing for reducing the input image, and clipping processing for cutting out a part of the input image. For example, when the size of the image display area represented by the area information is smaller than the size of the input image, the synthesizing unit 102 performs a reduction process for reducing the size of the input image to the size of the image display area.
In this embodiment, an example in which the number of input images arranged in the composite image is two will be described. However, the number of input images arranged in the composite image may be more than two. .

  In addition, the acquisition method of input image data is not specifically limited. For example, the image display apparatus may have a plurality of input interfaces, and a plurality of input image data may be acquired from the outside of the image display apparatus using the plurality of input interfaces. One image file including a plurality of input image data may be acquired from the outside of the image display device. At least one of the plurality of input image data may be acquired from a storage unit (not shown) included in the image display device. At least one of the plurality of input image data may be image data obtained by performing predetermined image processing (edge enhancement processing, blurring processing, luminance conversion processing, color conversion processing, etc.) on other input image data. At least one of the plurality of input image data may be generated in the image display device. The input image data generated in the image display device is, for example, image data representing an OSD image, an EPG image, or both.

The feature amount acquisition unit 103 acquires composite image data from the synthesis unit 102. Then, the feature quantity acquisition unit 103 displays, for each light source, a display target image (in a divided region where the light source is arranged (
The feature amount of the composite image) is acquired from the composite image data. In other words, the feature amount acquisition unit 103 acquires, for each divided region, the feature amount of the display target image (composite image) in the divided region from the combined image data. The feature amount acquisition unit 103 outputs the feature amount acquired for each light source to the first luminance determination unit 104 and the second luminance determination unit 105.
The feature amount includes, for example, a pixel value histogram of the display target image in the divided region, a representative value of the pixel value of the display target image in the divided region, a luminance value histogram of the display target image in the divided region, and the display target image of the divided region. Representative values of luminance values, etc. The representative value is a maximum value, a minimum value, an average value, an intermediate value, a mode value, or the like. In this embodiment, an example will be described in which a value representing the brightness of an image is acquired as the feature amount.

In this embodiment, a boundary vicinity light source is detected from a plurality of light sources by a part of functions of the backlight control unit 106. Specifically, when the display target image is a composite image in which a plurality of images are arranged, the vicinity of the boundary between two adjacent images (first image and second image) is selected from the plurality of light sources. The arranged light source is detected as a light source near the boundary.
In this embodiment, the light emission state of each light source is determined by a part of the function of the first brightness determination unit 104, a part of the function of the second brightness determination unit 105, and a part of the function of the backlight control unit 106. The target state (target luminance) is determined. Specifically, the target luminance of each light source is determined based on the feature amount acquired by the feature amount acquisition unit 103 and the detection result of the light source near the boundary. Although details will be described later, in this embodiment, for each light source, a change in target luminance of the light source near the boundary due to a change in the display target image is suppressed as compared with a light source near the non-boundary (light source other than the light source near the boundary). The target luminance of the light source is determined based on the feature amount acquired for the light source.
In this embodiment, the light emission luminance of each light source is controlled to the target luminance by some functions of the backlight control unit 106.
Note that the process for detecting the boundary vicinity light source, the process for determining the target brightness, and the process for controlling the light emission brightness may be executed by different functional units.

  The first luminance determination unit 104 stores first information (function or table) representing a first correspondence relationship that is a correspondence relationship between the feature amount and the light emission luminance. The first luminance determination unit 104 acquires the feature amount acquired for each light source from the feature amount acquisition unit 103. And the 1st brightness | luminance determination part 104 acquires the light emission brightness | luminance (1st brightness | luminance) of the 1st corresponding relationship matched with the feature-value acquired with respect to the light source for every light source from 1st information. . The first luminance determination unit 104 outputs the first luminance acquired for each light source to the backlight control unit 106.

  The second luminance determination unit 105 stores second information (function or table) representing a second correspondence relationship that is a correspondence relationship between the feature amount and the light emission luminance. In the second correspondence relationship, the light emission luminance range associated with the feature amount is narrower than the first correspondence relationship. The second luminance determination unit 105 acquires the feature amount acquired for each light source from the feature amount acquisition unit 103. Then, the second luminance determination unit 105 acquires, for each light source, the light emission luminance (second luminance) corresponding to the feature amount acquired for the light source from the second information. . The second luminance determination unit 105 outputs the second luminance acquired for each light source to the backlight control unit 106.

Note that the first correspondence relationship and the second correspondence relationship may or may not be determined in advance by the manufacturer or the like. For example, at least one of the first correspondence relationship and the second correspondence relationship may be determined according to a user operation, a plurality of input image data, an installation environment of the image display device, and the like.
The first information may be stored in a functional unit different from the first luminance determining unit 104. The second information may be stored in a functional unit different from the second luminance determining unit 105. The image display device may include a first storage unit that stores the first information separately from the first luminance determination unit 104. The image display apparatus may include a second storage unit that stores the second information separately from the second luminance determination unit 105. The image display apparatus may include a storage unit that stores both the first information and the second information separately from the first luminance determination unit 104 and the second luminance determination unit 105.

  When the display target image is a composite image in which a plurality of images are arranged, the backlight control unit 106 selects a boundary between two adjacent images (first image and second image) from among a plurality of light sources. A light source arranged in the vicinity is detected as a light source near the boundary. In the present embodiment, the light source near the boundary is detected based on the boundary position information output from the display area setting unit 101 and the position of each light source.

  And the backlight control part 106 determines the target brightness | luminance of each light source based on the detection result of a boundary vicinity light source. Specifically, the backlight control unit 106 uses the first luminance determined by the first luminance determination unit 104 for the non-boundary light source as the target luminance of the non-boundary light source (a light source other than the boundary light source). Set. And the backlight control part 106 sets the 2nd brightness | luminance which the 2nd brightness | luminance determination part 105 determined with respect to the said boundary vicinity light source as a target brightness | luminance of a boundary vicinity light source.

Thereafter, the backlight control unit 106 controls the light emission luminance of each light source to the target luminance.
Further, the backlight control unit 106 outputs the target luminance of each light source to the image correction unit 107.

  The image correction unit 107 acquires composite image data (display target image data) from the synthesis unit 102 and acquires target luminance of each light source from the backlight control unit 106. The image correcting unit 107 generates display image data by performing image processing based on the target luminance of each light source on the composite image data. For example, display image data is generated by performing image processing that suppresses a change in the maximum luminance of a display image (an image displayed on the screen) due to a change in target luminance on the composite image data. The image correction unit 107 outputs the display image data to the liquid crystal panel 109. Thereby, the transmittance of each liquid crystal element included in the liquid crystal panel 109 is controlled according to the display image data. Then, the light from the backlight module 108 is transmitted through each liquid crystal element at a transmittance corresponding to the display image data, whereby an image is displayed on the screen.

According to the configuration described above, the light source arranged in the vicinity of the boundary between the first image and the second image is detected as a boundary-side light source. Then, the light emission luminance of the non-boundary light source is controlled to the first luminance (the light emission luminance of the first correspondence relationship) associated with the feature amount acquired for the non-boundary light source. Further, the light emission luminance of the light source near the boundary is controlled to the second luminance (light emission luminance of the second correspondence relationship) associated with the feature amount acquired for the light source near the boundary.
Here, in the second correspondence relationship, the range of the light emission luminance associated with the feature amount is narrower than the first correspondence relationship. In other words, in the first correspondence relationship, the range of the light emission luminance associated with the feature amount is wider than that of the second correspondence relationship.
Thereby, the change of the light emission brightness | luminance (target brightness | luminance) of the light source near a boundary by the change of a display object image can be suppressed compared with a non-boundary light source.
As a result, image quality degradation of the display image caused by performing conventional local dimming control during multi-image display in which a plurality of images are displayed side by side can be suppressed while suppressing a decrease in the dynamic range and contrast of the display image. . Specifically, since the emission luminance of the light source near the non-boundary is controlled in a wide range, a display image with a wide dynamic range or a display with high contrast is obtained in a region away from the boundary between the first image and the second image. be able to. Since the light emission luminance of the light source near the boundary is controlled in a narrow range, the display luminance due to the variation in the feature amount of the second image is detected at the edge of the first image (the region irradiated with light from the light source near the boundary). Variations can be suppressed. Similarly, at the edge of the second image (region irradiated with light from the light source near the boundary), it is possible to suppress display luminance fluctuation due to fluctuations in the feature amount of the first image.

An example of the first correspondence and the second correspondence is shown in FIG. FIG. 2 shows that the feature value is an 8-bit value (0
˜255) is shown as an example. As described above, in the present embodiment, the feature amount represents the brightness of the image.
Note that the number of bits of the feature amount may be larger or smaller than 8 bits.
2 indicates a first correspondence relationship, and B indicates a second correspondence relationship. The first luminance determination unit 104 determines the first luminance according to the first correspondence A, and the second luminance determination unit 105 determines the second luminance according to the second correspondence B.
2 indicates the range of light emission luminance associated with the feature amount in the first correspondence relationship, and reference numeral RB indicates the range of light emission luminance associated with the feature amount in the second correspondence relationship. Indicates. As shown in FIG. 2, in this embodiment, the range RB is narrower than the range RA. Therefore, in the second correspondence relationship, the change in the light emission luminance due to the change in the feature amount is smaller than that in the first correspondence relationship.

2 indicates the lowest value of the light emission luminance of the first correspondence relationship, and mB indicates the lowest value of the light emission luminance of the second correspondence relationship. In the example of FIG. 2, the minimum value mB of the light emission luminance of the second correspondence relationship is higher (larger) than the minimum value mA of the light emission luminance of the first correspondence relationship.
Human vision is sensitive to changes in the dark. Therefore, by using a value higher than the minimum value mA as the minimum value mB, it is possible to make it difficult to perceive the above-described change in display luminance (change in display luminance near the boundary between the first image and the second image). it can. Further, in a region away from the boundary between the first image and the second image, the black level (black display luminance) of the display image can be reduced, and the occurrence of black floating can be suppressed.

In FIG. 2, the difference between the light emission luminance of the first correspondence relationship associated with the large feature amount and the light emission luminance of the second correspondence relationship is the light emission of the first correspondence relationship associated with the small feature amount. It is smaller than the difference between the luminance and the emission luminance of the second correspondence relationship. In FIG. 2, a large feature amount represents high brightness, and a small feature amount represents low brightness. Specifically, in FIG. 2, the difference between the light emission luminance of the first correspondence relationship and the light emission luminance of the second correspondence relationship decreases linearly as the feature amount (brightness represented by the feature amount) increases. In FIG. 2, the maximum value of the light emission luminance of the first correspondence relationship is the same value M as the maximum value of the light emission luminance of the second correspondence relationship.
As a result, the larger the feature amount acquired for the boundary vicinity light source, the more difficult it is to perceive the difference in control method between the boundary vicinity light source and the non-boundary vicinity light source. Then, in the vicinity of the boundary between the first image and the second image, the larger the feature amount acquired for the light source near the boundary, the difference in display luminance and display color (color on the screen) from other regions is perceived. Can be difficult.

  The first correspondence relationship and the second correspondence relationship are not limited to the correspondence relationships shown in FIG. For example, at least one of the first correspondence relationship and the second correspondence relationship may be a correspondence relationship in which the light emission luminance increases stepwise as the feature amount increases. The minimum value of the light emission luminance of the second correspondence relationship may be lower than the minimum value of the light emission luminance of the first correspondence relationship. The maximum value of the light emission luminance of the first correspondence relationship may be higher or lower than the maximum value of the light emission luminance of the second correspondence relationship.

A method for detecting the light source near the boundary will be described in detail with reference to FIGS.
In this embodiment, the display area setting unit 101 is the center of the first image and the second image in the arrangement direction of the first image and the second image (the image display area of the first image and the image display area of the second image). Boundary position information representing the position as the position of the boundary between the first image and the second image is generated. A position shifted from the center position of the first image and the second image may be used as the position of the boundary between the first image and the second image.
And the backlight control part 106 detects the light source which irradiates light to both the area | region where a 1st image is displayed, and the area | region where a 2nd image is displayed as a boundary vicinity light source.

A symbol d in FIGS. 3A to 3C indicates a distance from the boundary position to the first image or the second image. In this embodiment, since the center position of the first image and the second image is used as the boundary position, the distance from the boundary position to the first image is equal to the distance from the boundary position to the second image.
Moreover, the code | symbol K1-K3 of Fig.3 (a)-3 (c) shows the position where the light source is arrange | positioned.
As shown in FIGS. 3A to 3C, in this embodiment, the light source irradiates light from a position K <b> 1 to K <b> 3 where the light source is arranged to a region of radius r in the screen region. .
The distance d can be calculated based on the boundary position and the image display area. The distance d may be included in the boundary position information, or may be calculated by the backlight control unit 106 (or other functional unit).
The positions K1 to K3 and the radius r are predetermined.
The backlight control unit 106 detects a light source that satisfies p ≦ r−d (p is a distance from the light source to the boundary position) as a light source near the boundary. In the example of FIGS. 3A to 3C, the light source at the position K1 is not detected as the light source near the boundary, and the light sources at the positions K2 and K3 are detected as the light sources near the boundary.

  In addition, the detection method of a boundary vicinity light source is not restricted to the said method. For example, irradiation area information representing an area (irradiation area) where the light source emits light may be prepared in advance. Based on the irradiation region represented by the irradiation region information and the image display region represented by the display region information, light is emitted to both the region where the first image is displayed and the region where the second image is displayed. The illuminating light source may be detected as a boundary vicinity light source.

The effects of the present embodiment will be described in detail with reference to FIGS. 17 (a) to 17 (c) and FIGS. 4 (a) to 4 (c).
17A to 17C show an example of the operation of the conventional image display device, and FIGS. 4A to 4C show an example of the operation of the image display device according to the present embodiment. . In FIGS. 17 (a) to 17 (c) and FIGS. 4 (a) to 4 (c), information on the current frame is written on the left side, and information on the next frame (next frame of the current frame) is shown on the right side. Have been described.
FIG. 17A and FIG. 4A show display target images (composite images). In FIG. 17A and FIG. 4A, the luminance value of the image data is expressed in color so that the color changes from black to white as the luminance value of the image data increases. In FIG. 17A and FIG. 4A, the first image and the second image are arranged in the composite image.
FIG. 17B and FIG. 4B show the light emission luminance of each light source (divided region). In FIG. 17B and FIG. 4B, a total of 25 light sources (divided regions) of 5 in the horizontal direction and 5 in the vertical direction are arranged. In FIGS. 17B and 4B, the light emission luminance is expressed in color so that the color changes from black to white as the light emission luminance increases. The light source in the third column is a near-boundary light source that emits light to both the area where the first image is displayed and the area where the second image is displayed.
FIG. 17C and FIG. 4C show display images. In FIG. 17C and FIG. 4C, the display luminance is expressed in color so that the color changes from black to white as the display luminance increases.
The arrangement and number of light sources are not particularly limited. For example, the number of light sources may be more or less than 25. The plurality of light sources may be arranged in a staggered pattern.

In FIG. 17A, the first image changes from the current frame to the next frame. Then, due to the change in the first image, the composite image in the divided area where the light source near the boundary is arranged is changed from a dark image to an image including a dark area and a bright area.
In the conventional image display device, as shown in FIG. 17B, the light emission luminance of the light source near the boundary varies according to the change in the brightness (feature amount) of the composite image in the divided area where the light source near the boundary is arranged. It changes a lot.
For this reason, in the conventional image display device, as shown in FIG. 17C, the display brightness of the second image greatly changes as the first image changes. Specifically, the degree of black floating in the second image changes greatly. Such a change in display luminance is perceived as flicker.

Also in FIG. 4A, the first image changes from the current frame to the next frame, as in FIG. 17A. Then, due to the change in the first image, the composite image in the divided area where the light source near the boundary is arranged is changed from a dark image to an image including a dark area and a bright area.
However, in this embodiment, as shown in FIG. 4B, a change in emission luminance of the light source near the boundary in accordance with a change in brightness (feature amount) of the composite image in the divided area where the light source near the boundary is arranged. However, it is suppressed compared with the conventional image display apparatus. Specifically, when the brightness of the combined image in the divided area where the light source near the boundary is reduced, the light emission luminance of the light source near the boundary is controlled so that the light emission luminance of the light source near the boundary does not decrease excessively. The
Thereby, in the present embodiment, as shown in FIG. 4C, the change in the display luminance of the second image accompanying the change in the first image can be reduced. Specifically, it is possible to reduce the change in the black float of the second image.

  Furthermore, in this embodiment, the light emission luminance of the non-boundary light source is controlled in a wide range. Specifically, when the brightness of the composite image in the divided area where the non-boundary light source is arranged decreases, the light emission brightness of the non-boundary light source decreases sufficiently so that the light emission brightness of the non-boundary light source decreases sufficiently. Is controlled. Thereby, in the area | region away from the boundary of a 1st image and a 2nd image, a black float can fully be reduced. In a region away from the boundary between the first image and the second image, a display image with a wide dynamic range and a display image with a high contrast can be obtained.

A specific example of the operation of the conventional image display apparatus and the image display apparatus according to the present embodiment will be described with reference to FIGS. 6 (a) and 6 (b). 6A and 6B show an example in which a composite image (display target image) in which an OSD image is superimposed on a dark main image is displayed. 6A shows a specific example of the operation of the conventional image display apparatus, and FIG. 6B shows a specific example of the operation of the image display apparatus according to the present embodiment.
Three items 1 to 3 are shown in the OSD images of FIGS. 6A and 6B, and any one of the items 1 to 3 is selected according to a user operation. A value higher than that of other items is set as the luminance value of the selection item (selected item).
FIGS. 6A and 6B show an example in which the selected item transitions from item 1 to item 3. FIG.

  As shown in FIG. 6A, in the conventional image display device, the light emission luminance of the light sources arranged around the selection item is controlled to a high value, and the light emission luminances of other light sources are controlled to a low value. . Therefore, the black float at the end of the main image (the end on the OSD image side) is visually recognized, and the area where the black float is visually recognized transitions according to the user operation. And in the conventional image display apparatus, the change of black floating is large. As described above, in the conventional image display device, the change in the black float is large, and the change in the black float transitions according to the user operation. Therefore, the change in the black float is easily perceived as an obstacle.

  As shown in FIG. 6B, in this embodiment, since the change in the light emission luminance of the light source arranged in the vicinity of the boundary between the main image and the OSD image is suppressed, the change in the black float can be suppressed. it can. As a result, it is possible to make it difficult to perceive changes in black float.

It supplements about the subject of a prior art and the effect of a present Example.
In general, when the light emission luminance of the light source changes abruptly, a change in the degree of black float is visually recognized as an interference.
As a conventional technique, a technique for controlling the light emission luminance of each light source has been proposed so that the temporal change of the light emission luminance of the light source is suppressed. By using such a conventional technique, it is possible to make it difficult to visually recognize the change in the black float. However, when such a conventional technique is used, the light emission luminance of the light source cannot be sufficiently increased, and the image quality of the display image may be deteriorated.
Note that the display luminance can be increased by image processing. However, since the pixel value has an upper limit value, sufficient display luminance cannot be obtained even if image processing is performed, and the image quality of the display image may be deteriorated.

In image data that is not composite image data (image data representing only one image), the correlation (similarity) between temporal and spatial images is high. For this reason, when displaying an image based on such image data, it is unlikely that rapid changes in the light emission luminance of the light source frequently occur.
However, in the composite image data, the correlation between a plurality of images arranged in the composite image is low, and the correlation between temporal and spatial images is also low. For this reason, it is considered that when the image based on the composite image data is displayed, a rapid change in the light emission luminance of the light source occurs frequently. Specifically, it is considered that a rapid change in the light emission luminance of the light source arranged in the vicinity of the boundary between the first image and the second image occurs at a high frequency.

  Therefore, in this embodiment, when an image based on the composite image data is displayed, fluctuations in the emission luminance of the light source near the boundary are suppressed as compared with the light source near the non-boundary. Thereby, the fluctuation | variation of the display brightness | luminance in the vicinity of the boundary of a 1st image and a 2nd image can be suppressed, suppressing the fall of the dynamic range of a display image, or contrast.

  As described above, according to the present embodiment, image quality deterioration of a display image caused by performing conventional local dimming control during multi-image display is suppressed while suppressing a decrease in dynamic range and contrast of the display image. be able to.

In addition, the detection method of a boundary vicinity light source is not restricted to the method mentioned above.
For example, a light source whose distance to the position of the boundary between the first image and the second image is not more than a first threshold value may be detected as a light source near the boundary.
Also, a light source near the boundary (first light source) disposed on the side of the region where the first image is displayed with respect to the boundary position, and a region on the side of the region where the second image is displayed with respect to the boundary position. The boundary vicinity light source (second light source) may be detected using different threshold values. The first light source is a light source that is disposed on the side of the region where the first image is displayed with respect to the boundary position, and the distance to the boundary position is equal to or less than the second threshold value. The second light source is a light source that is disposed on the side of the region where the second image is displayed with respect to the boundary position, and whose distance to the boundary position is equal to or less than a third threshold value. If a large value is used as the second threshold value and a small value is used as the third threshold value, it is possible to reduce the influence of the change in the feature amount of the first image on the display luminance of the second image. Further, if a large value is used as the second threshold value and a small value is used as the third threshold value, most of the light sources arranged on the side of the region where the second image is displayed rather than the boundary position are non-boundary. It can be used as a near light source. As a result, a display image with a wider dynamic range of the second image and a display image with a higher contrast of the second image can be obtained.
Note that the first threshold value, the second threshold value, and the third threshold value may or may not be predetermined by a manufacturer or the like. For example, at least one of the first threshold value, the second threshold value, and the third threshold value may be determined according to a user operation, a plurality of input image data, an installation environment of the image display device, and the like.
Note that the first luminance may be acquired only for the non-boundary light source, and the second luminance may be acquired only for the boundary light source.

Note that the method for determining the target luminance of the light source near the boundary is not limited to the method described above.
For example, the target state of the light source near the boundary may be determined so as to satisfy the following conditions 1 and 2.
Condition 1: The shorter the distance from the light source near the boundary to the position of the boundary, the closer the target luminance of the light source near the boundary is to the second luminance associated with the feature amount acquired for the light source near the boundary.
Condition 2: The longer the distance from the light source near the boundary to the position of the boundary, the closer the target luminance of the light source near the boundary is to the first luminance associated with the feature amount acquired for the light source near the boundary.
Such target luminance is obtained by weighting the first luminance and the second luminance associated with the feature amount acquired for the light source near the boundary with a weight according to the distance from the light source near the boundary to the position of the boundary. It can be determined by adding and synthesizing.

FIGS. 5A to 5C show examples in which the target luminance of the light source near the boundary is determined by weighting synthesis. 5A to 5C, information on the current frame is described on the left side, and information on the next frame is described on the right side.
FIG. 5A shows a display target image (composite image). FIG. 5A is the same as FIG. FIG. 5B shows the light emission luminance of each light source (divided region). The light sources in the second to fourth columns are near-boundary light sources that irradiate both the area where the first image is displayed and the area where the second image is displayed. FIG. 5C shows a display image.

Here, the first luminance and the second luminance associated with the feature amount acquired for the light source near the boundary are weighted and synthesized with a weight according to the distance from the light source near the boundary to the position of the boundary. Thus, the target luminance of the boundary vicinity light source is determined.
Therefore, in FIG. 5B, the same value is acquired as the feature amount of the current frame for the light source in the third column and the light source in the fourth column, but the emission luminance of the light source in the fourth column is 3 columns. It is controlled to a value lower than the light emission luminance of the eye light source.
As shown in FIG. 5C, even in the configuration in which the target brightness of the light source near the boundary is determined by weighted synthesis, the change in display brightness near the boundary between the first image and the second image can be reduced. it can. In addition, as shown in FIG. 5C, by rapidly determining the target luminance of the light source near the boundary by weighting synthesis, the display luminance changes rapidly between the region near the boundary and the region away from the boundary. Can be suppressed.

<Example 2>
Hereinafter, an image display apparatus and a control method thereof according to Embodiment 2 of the present invention will be described with reference to the drawings.
In the first embodiment, an example has been described in which the image display apparatus acquires a plurality of input image data from the outside and generates composite image data based on the plurality of input image data. Further, in the first embodiment, the example in which the image display device generates the display area information and the boundary position information according to the user operation has been described.
In the present embodiment, an example will be described in which the image display apparatus acquires composite image data, display area information, and boundary position information from the outside.
Display area information acquired from the outside includes, for example, window position information of a multi-window OS that operates in an external apparatus (for example, a PC), display position information that is managed by a web browser, an image viewer, or the like that operates in the external apparatus. , Etc.

FIG. 7 is a block diagram illustrating an example of a functional configuration of the image display apparatus according to the present embodiment.
7, the same reference numerals as those in the first embodiment are assigned to the same functional units as those in the first embodiment (FIG. 1), and the description thereof is omitted.

The composite image data acquired from the outside of the image display device is input to the feature amount acquisition unit 103 and the image correction unit 107.
The display area setting unit 201 acquires display area information and boundary position information from outside the image display device. Then, the display area setting unit 201 outputs display area information and boundary position information to the backlight control unit 106. At least one of the display area information and the boundary position information is superimposed on the header area of the composite image data, for example. Then, the display area setting unit 201 extracts at least one of display area information and boundary position information from the composite image data.
Note that at least one of the display area information and the boundary position information may be input to the image display device independently from the composite image data. For example, at least one of the display area information and the boundary position information may be input to the image display device using a dedicated communication line.
As described in the first embodiment, the display area information may not be used by the backlight control unit 106. Therefore, the display area setting unit 201 only needs to acquire boundary position information, and does not have to acquire display area information.
The boundary position information may not be acquired from the outside of the image display device. The display area setting unit 201 may generate boundary position information based on the image display area represented by the display area information.

In the present embodiment, as in the first embodiment, a light source arranged in the vicinity of the boundary between the first image and the second image is detected as a light source near the boundary. Then, the light emission luminance of the non-boundary light source is controlled to the first luminance (the light emission luminance of the first correspondence relationship) associated with the feature amount acquired for the non-boundary light source. Further, the light emission luminance of the light source near the boundary is controlled to the second luminance (light emission luminance of the second correspondence relationship) associated with the feature amount acquired for the light source near the boundary.
As a result, as in the first embodiment, the deterioration in the display image quality caused by the conventional local dimming control during multi-image display in which a plurality of images are displayed side by side is suppressed, and the decrease in the dynamic range and contrast of the display image is suppressed. However, it can be suppressed.

A specific example of the operation of the conventional image display apparatus and the image display apparatus according to the present embodiment will be described with reference to FIGS. 8 (a) and 8 (b). FIGS. 8A and 8B show an example in which a composite image (display target image) in which a viewer image is superimposed on a dark background image is displayed. FIG. 8A shows a specific example of the operation of the conventional image display apparatus, and FIG. 8B shows a specific example of the operation of the image display apparatus according to the present embodiment.
In the viewer image area, a moving image is displayed, or a plurality of images (moving images and still images) are switched and displayed. For this reason, the luminance value of the viewer image changes frequently.
8A and 8B show an example in which the luminance value of the viewer image increases.

  As shown in FIG. 8A, in the conventional image display device, the light emission luminance of the light source arranged in the vicinity of the area where the viewer image is displayed changes greatly according to the change in the brightness of the viewer image. . For this reason, the degree of black float at the end of the background image (the end on the viewer image side) changes greatly according to the change in the brightness of the viewer image. As described above, in the conventional image display device, since the change in the black float is large, the change in the black float is easily perceived as an interference.

  As shown in FIG. 8B, in this embodiment, the change in the light emission luminance of the light source arranged in the vicinity of the boundary between the background image and the viewer image is suppressed. it can. As a result, it is possible to make it difficult to perceive changes in black float.

  As described above, according to the present embodiment, the same effect as that of the first embodiment can be obtained when the composite image data, the display area information, and the boundary position information are acquired from the outside of the image display device. it can.

<Example 3>
Hereinafter, an image display apparatus and a control method thereof according to Embodiment 3 of the present invention will be described with reference to the drawings.
9 and 10 are block diagrams illustrating an example of a functional configuration of the image display apparatus according to the present embodiment. FIG. 9 shows an example in which a plurality of input image data is acquired from the outside of the image display device, and FIG. 10 shows that composite image data, display area information, and boundary position information are acquired from the outside of the image display device. An example will be shown.
9 and 10, the same functional parts as those in the first and second embodiments (FIGS. 1 and 7) are denoted by the same reference numerals as those in the first and second embodiments, and the description thereof is omitted.

The feature amount acquisition unit 303 executes the same processing as the feature amount acquisition unit 103 of the first and second embodiments.
Further, the feature amount acquisition unit 303 executes a first acquisition process and a second acquisition process. The first acquisition process is a process of acquiring a first feature amount that is a feature amount of the first image. The second acquisition process is a process of acquiring a second feature amount that is a feature amount of the second image. The feature quantity acquisition unit 303 outputs the first feature quantity and the second feature quantity to the feature quantity comparison unit 310.

A method for acquiring the first feature value and the second feature value will be described.
The feature amount acquisition unit 303 acquires display area information from the display area setting unit 101 or the display area setting unit 201. Then, the feature amount acquisition unit 303 acquires the first feature amount and the second feature amount based on the feature amount acquired for each light source and the display area information.
In the present embodiment, the feature amount acquisition unit 303 detects a first divided region and a second divided region from a plurality of divided regions based on the display region information. The first divided area is a divided area where the first image is displayed and the second image is not displayed. The second divided area is a divided area in which the first image is not displayed and the second image is displayed. Then, the feature amount acquisition unit 303 acquires the feature amount of the composite image (display target image) in the first divided region as the first feature amount. When there are a plurality of first divided regions, the feature amount acquisition unit 303 acquires a representative feature amount representing the feature amount of the composite image in each first divided region as the first feature amount. The feature amount acquisition unit 303 acquires the feature amount of the composite image (display target image) in the second divided region as the second feature amount. When there are a plurality of second divided regions, the feature amount acquisition unit 303 acquires a representative feature amount representing the feature amount of the composite image in each second divided region as the second feature amount. The representative feature amount is a maximum value, minimum value, average value, mode value, intermediate value, or the like of the feature amount. The representative feature amount is preferably an average value or a mode value of the feature amounts.

Note that at least one of the first acquisition process and the second acquisition process may be executed by a functional unit different from the feature amount acquisition unit 303.
In addition, the acquisition method of a 1st feature-value and a 2nd feature-value is not restricted to the said method. For example, the first feature amount may be acquired from the image data representing the first image, and the second feature amount may be acquired from the image data representing the second image. The image data representing the first image and the image data representing the second image may be extracted from the composite image data, or may be acquired from outside the image display device.
Note that the first feature value and the second feature value are not limited to the above feature values. For example, the first feature amount may be a histogram of pixel values (or luminance values) of the entire first image or a representative value. The second feature amount may be a histogram or a representative value of pixel values (or luminance values) of the entire second image.
The first divided area and the second divided area are not limited to the divided areas. For example, a divided area where at least the first image is displayed may be detected as the first divided area. A divided area where at least the second image is displayed may be detected as the second divided area. Then, the divided areas where both the first image and the second image are displayed may be detected as the first divided area and the second divided area. A divided area in which the first image is displayed and the display size of the first image is larger than the display size of the second image may be detected as the first divided area. A divided area in which the second image is displayed and the display size of the second image is larger than the display size of the first image may be detected as the second divided area.

The feature amount comparison unit 310 acquires the first feature amount and the second feature amount from the feature amount acquisition unit 303, and whether the difference (absolute value) between the first feature amount and the second feature amount is less than the fifth threshold value. Judge whether or not. Then, the feature amount comparison unit 310 outputs a change suppression instruction to the backlight control unit 306 when the difference between the first feature amount and the second feature amount is equal to or greater than the fifth threshold value. The feature amount comparison unit 310 does not output a change suppression instruction to the backlight control unit 306 when the difference between the first feature amount and the second feature amount is less than the fifth threshold value.
Note that the fifth threshold value may or may not be determined in advance by a manufacturer or the like. For example, the fifth threshold value may be determined according to a user operation, a plurality of images arranged in the composite image, an installation environment of the image display device, and the like.

When a change suppression instruction is output from the feature amount comparison unit 310, the backlight control unit 306 performs the same processing as the backlight control unit 106 of the first and second embodiments. Therefore, when the difference between the first feature value and the second feature value is equal to or greater than the fifth threshold value, the same effect as in the first and second embodiments can be obtained.
When the change suppression instruction is not output from the feature amount comparison unit 310, the backlight control unit 306 determines the target luminance of each light source by regarding the boundary vicinity light source as a non-boundary vicinity light source. That is, when the difference between the first feature value and the second feature value is less than the fifth threshold value, the backlight control unit 306 regards the light source near the boundary as the light source near the boundary, and sets the target luminance of each light source. decide. In the present embodiment, when a change suppression instruction is not output from the feature amount comparison unit 310, the backlight control unit 306 uses the first luminance output from the first luminance determination unit 104 as the target luminance of each light source. Set. Then, the backlight control unit 306 controls the light emission luminance of each light source to the target luminance.

  The effects of this embodiment will be described with reference to FIGS. 11 (a) and 11 (b). FIG. 11A shows an example where the difference between the first feature value and the second feature value is less than the fifth threshold value, and FIG. 11B shows the difference between the first feature value and the second feature value. An example in the case of being equal to or greater than the fifth threshold is shown. Here, an example will be described in which the feature amount represents the brightness of the image, and the difference between the first feature amount and the second feature amount represents the difference between the brightness of the first image and the brightness of the second image.

In this embodiment, when the difference between the first feature value and the second feature value is less than the fifth threshold value, the light source near the boundary is regarded as a non-boundary light source, and the emission luminance of the light source near the boundary is also near the non-boundary. It is controlled over a wide range like the light source.
As shown in FIG. 11A, when the brightness of the first image and that of the second image are the same, it is difficult to perceive a change in display luminance near the boundary. For example, when both the first image and the second image are bright images, the human eye adapts to bright display luminance, and the sensitivity of the human eye to low display luminance decreases. For this reason, when both the first image and the second image are bright images, it is difficult to perceive a change in display luminance in the vicinity of the boundary. Therefore, when the brightness of the first image is the same as that of the second image, there is no problem even if the light source near the boundary is regarded as a non-boundary light source.
As described above, when the difference between the first feature value and the second feature value is less than the fifth threshold value, the light emission luminance of the light source near the boundary is controlled in a wide range like the light source near the boundary. . Thereby, when the difference between the first feature value and the second feature value is less than the fifth threshold value, it is possible to obtain a display image with reduced black float compared to the first and second embodiments. When the difference between the first feature value and the second feature value is less than the fifth threshold value, the display image has a wider dynamic range than the first and second embodiments and the contrast is higher than those of the first and second embodiments. A display image can be obtained.

As shown in FIG. 11B, when the brightness of the first image and the second image are greatly different, the display luminance fluctuation in the vicinity of the boundary is easily perceived.
In the present embodiment, when the difference between the first feature value and the second feature value is equal to or greater than the fifth threshold value, the process of suppressing the change in the light emission luminance of the light source near the boundary is performed as in the first and second embodiments. Executed. Thereby, when the difference between the first feature value and the second feature value is equal to or larger than the fifth threshold value, it is possible to suppress a change in display luminance in the vicinity of the boundary.

As described above, according to the present embodiment, the process for suppressing the change in the light emission luminance of the light source near the boundary is performed only when the difference between the first feature value and the second feature value is equal to or greater than the fifth threshold value. Done. If the difference between the first feature value and the second feature value is less than the fifth threshold value, the boundary vicinity light source is regarded as a non-boundary vicinity light source. Thereby, when the change of the display brightness in the vicinity of the boundary is easily perceived, the same effect as in the first and second embodiments can be obtained. When it is difficult to perceive a change in display brightness near the boundary, it is possible to obtain a display image having a wider dynamic range than those of the first and second embodiments and a display image having a higher contrast than those of the first and second embodiments.

  In the present embodiment, the example in which the light source near the boundary is regarded as the non-boundary light source when the difference between the first feature value and the second feature value is less than the fifth threshold value has been described, but the present invention is not limited thereto. For example, the change in the target luminance of the light source near the boundary due to the change in the composite image (display target image) is more greatly suppressed as the difference between the first feature value and the second feature value is larger than in the non-boundary light source. The target brightness of each light source may be determined. Such processing can be realized, for example, by setting a value obtained by synthesizing the first luminance and the second luminance with a weight according to the difference between the first feature amount and the second feature amount as the target luminance of the light source near the boundary. . By performing such processing, a more appropriate display image can be obtained. Specifically, the degree of suppression of the change in display luminance near the boundary can be changed continuously (or stepwise) according to the ease of perceiving the change in display luminance. Further, the dynamic range and contrast of the display image in the vicinity of the boundary can be changed continuously (or stepwise) according to the ease of perceiving the change in display luminance.

<Example 4>
Hereinafter, an image display apparatus and a control method thereof according to Embodiment 4 of the present invention will be described with reference to the drawings.
The configuration of the image display apparatus according to the present embodiment is the same as that of the first to third embodiments (FIGS. 1, 7, 9, and 10). In the present embodiment, the second correspondence relationship is different from those in the first to third embodiments.

An example of the first correspondence relationship and the second correspondence relationship according to the present embodiment is shown in FIG. FIG. 12A shows an example in which the feature amount is an 8-bit value (0 to 255). In this embodiment, the feature amount represents the brightness of the image.
As shown in FIG. 12A, also in this embodiment, the emission luminance range RB associated with the feature amount in the second correspondence relationship B is associated with the feature amount in the first correspondence relationship A. It is narrower than the emission luminance range RA.
Also, as shown in FIG. 12A, also in this embodiment, the minimum value mB of the light emission luminance of the second correspondence relationship B is higher (larger) than the minimum value mA of the light emission luminance of the first correspondence relationship A.
Also, as shown in FIG. 12A, also in this embodiment, the difference between the light emission luminance of the first correspondence relationship and the light emission luminance of the second correspondence relationship associated with a large feature amount is a small feature amount. The difference between the light emission luminance of the first correspondence relationship and the light emission luminance of the second correspondence relationship is smaller.

  However, in the second correspondence relationship B according to the present embodiment, the light emission luminance higher than the light emission luminance of the first correspondence relationship A associated with the feature amount is associated with the feature amount less than the threshold T. ing. The feature amount equal to or greater than the threshold value T is associated with the same light emission luminance as the light emission luminance of the first correspondence A associated with the feature amount. A feature quantity less than the threshold value T represents brightness less than the fourth threshold value, and a feature quantity greater than or equal to the threshold value T represents brightness greater than or equal to the fourth threshold value.

Therefore, in the present embodiment, when the feature amount acquired for the light source near the boundary is less than the threshold value T, the change in the emission luminance of the light source near the boundary due to the change in the display target image (composite image) The emission luminance of the light source near the boundary is controlled so as to be suppressed as compared. As a result, a change in display luminance near the boundary can be suppressed.
When the feature amount acquired for the boundary vicinity light source is equal to or greater than the threshold T, the light emission luminance of the boundary vicinity light source is controlled by the same method (reference) as the non-boundary vicinity light source. As a result, it is possible to obtain a display image in which black floating is further reduced. In addition, a display image with a wider dynamic range and a display image with a higher contrast can be obtained. Furthermore, by controlling the light emission luminance of the light source near the boundary by the same method (reference) as the light source near the non-boundary, the light emission luminance of the light source near the boundary can be controlled to a lower value, thereby reducing power consumption. Can do.

Note that the black float and the change in display brightness are more easily perceived as the image is darker and less likely to be perceived as the image is brighter. For this reason, when the feature amount acquired for the light source near the boundary is equal to or greater than the threshold value T, the black float and the change in display luminance are difficult to perceive. There is no problem even if it is controlled.
Note that the threshold value T and the fourth threshold value may or may not be determined in advance by a manufacturer or the like. For example, the threshold value T and the fourth threshold value may be determined according to a user operation, a plurality of images arranged in the composite image, an installation environment of the image display device, and the like.

  As described above, according to the present embodiment, it is possible to suppress a change in display luminance in the vicinity of the boundary when a change in display luminance in the vicinity of the boundary is easily perceived. When it is difficult to perceive a change in display brightness near the boundary, a display image with a wider dynamic range and a display image with a higher contrast can be obtained.

  The second correspondence relationship is not limited to the correspondence relationship described above. For example, the correspondence relationship B shown in FIG. 12B may be used as the second correspondence relationship. In FIG. 12B, the difference between the light emission luminance of the first correspondence relationship A and the light emission luminance of the second correspondence relationship B decreases exponentially as the feature amount (brightness represented by the feature amount) increases. ing. In the second correspondence relationship B shown in FIG. 12A, the slope (change in the light emission luminance of the light source near the boundary with respect to the change in the feature amount) changes discontinuously with the threshold value T. For this reason, when the second correspondence relationship B shown in FIG. 12A is used, there is a risk that the change of inclination may be perceived as an obstruction. In the second correspondence relationship B shown in FIG. 12B, since the inclination changes continuously, the perception of the disturbance can be suppressed.

<Example 5>
Hereinafter, an image display apparatus and a control method thereof according to Embodiment 5 of the present invention will be described with reference to the drawings.
The configuration of the image display apparatus according to the present embodiment is the same as that of the first to fourth embodiments (FIGS. 1, 7, 9, and 10). In the present embodiment, the processing of the backlight control unit is different from those in the first to fourth embodiments.

  The backlight control unit according to the present embodiment determines the target luminance of each light source in the same manner as the backlight control units according to the first to fourth embodiments. The backlight control unit according to the present embodiment, when there are a plurality of light sources near the boundary, represents the target luminance of each boundary light source that represents the target luminance determined for each light source near the boundary. To correct. Thereafter, the backlight control unit according to the present embodiment controls the light emission luminance of each light source to the target luminance. The representative target brightness is the maximum value, the minimum value, the average value, the mode value, the intermediate value, etc. of the target brightness. In order to suppress the pixel value of the display image data (image data after image processing by the image correction unit 107) from being limited to the upper limit value, the representative target luminance is preferably the maximum value of the target luminance.

The effects of this embodiment will be described in detail with reference to FIGS. 13 (a) and 13 (b).
FIG. 13A shows an example of a display image of a conventional image display device, and FIG. 13B shows an example of a display image of the image display device according to the present embodiment. In FIG. 13A, the display image of the current frame is shown on the left side, and the display image of the next frame (next frame of the current frame) is shown on the right side. FIG. 13B shows a display image of the current frame.

As described in the first embodiment, in the conventional image display device, the display luminance in the vicinity of the boundary greatly changes due to the change in the composite image.
Further, in the example of FIG. 13A, since the light emission luminance of the light sources near the boundary is nonuniform, luminance unevenness (specifically, nonuniform black floating) occurs in the vicinity of the boundary. Such non-uniform black float is perceived as a large disturbance compared to uniform black float. When the emission color of the light source is controlled, color unevenness may occur. Specifically, color unevenness occurs when the light emission colors of a plurality of light sources near the boundary are not uniform.
In this embodiment, the light emission states of a plurality of light sources near the boundary are controlled to the same target state (representative target state representing the target state of each boundary light source). Accordingly, as shown in FIG. 13B, luminance unevenness and color unevenness in the vicinity of the boundary can be suppressed.

  As described above, according to the present embodiment, after the target state of each boundary light source is corrected to the same target state, the light emission state of each light source is controlled to the target state. Thereby, luminance unevenness and color unevenness in the vicinity of the boundary can be suppressed.

<Example 6>
Hereinafter, an image display apparatus and a control method thereof according to Embodiment 6 of the present invention will be described with reference to the drawings.
The configuration of the image display apparatus according to the present embodiment is the same as that of the first to fifth embodiments (FIGS. 1, 7, 9, and 10). In a present Example, the process of a 1st brightness | luminance determination part and a 2nd brightness | luminance determination part differs from Examples 1-5.

  The first luminance determination unit stores first information (function or table) representing a first correspondence relationship that is a correspondence relationship between the feature amount and the light emission luminance. The first luminance determination unit acquires the feature amount acquired for each light source from the feature amount acquisition unit. Then, the first luminance determination unit acquires, for each light source, the light emission luminance (first luminance) having the first correspondence relationship associated with the feature amount acquired for the light source from the first information. Thereafter, the first luminance determination unit outputs the first luminance acquired for each light source to the backlight control unit.

  The first luminance determination unit acquires the feature amount acquired for each light source from the feature amount acquisition unit. And a 1st brightness | luminance determination part determines the target brightness | luminance (1st brightness | luminance) of the said light source based on the feature-value acquired with respect to the light source for every light source. The first luminance determining unit outputs the first luminance determined for each light source to the backlight control unit.

  The second luminance determination unit acquires the feature amount acquired for each light source from the feature amount acquisition unit. And a 2nd brightness | luminance determination part determines the target brightness | luminance (2nd brightness | luminance) of the said light source based on the feature-value acquired with respect to the light source for every light source. The second luminance determining unit outputs the second luminance determined for each light source to the backlight control unit.

In the present embodiment, the first luminance determining unit and the second luminance determining unit periodically determine the target luminance (first luminance and second luminance). Specifically, the first luminance and the second luminance are determined for each frame of display target image data (composite image data). Then, the second luminance determining unit determines the target luminance whose temporal change is suppressed as compared with the first luminance as the second luminance.
The backlight control unit has the same function as in the first to fifth embodiments.
Therefore, in the present embodiment, for each light source, the target luminance of the light source is acquired for the light source so that the temporal change in the target luminance of the light source near the boundary is suppressed as compared to the non-boundary light source. Determined based on quantity.
As a result, a change in the target state of the near-boundary light source due to a change in the composite image (display target image) can be suppressed as compared to a light source other than the near-boundary light source. As a result, image quality degradation of the display image caused by performing conventional local dimming control during multi-image display in which a plurality of images are displayed side by side can be suppressed while suppressing a decrease in the dynamic range and contrast of the display image.

The frequency with which the first luminance and the second luminance are determined (updated) is not limited to the above frequency. For example, the first luminance and the second luminance may be determined every predetermined number of frames. The first luminance and the second luminance may be determined every predetermined time. The first luminance and the second luminance may be updated each time a user operation that causes a change in the composite image is performed. The user operation that causes the composite image to be changed is, for example, a user operation using an OSD image. The user operation that causes the change of the composite image includes a user operation for changing at least one of the first image and the second image to another image, a user operation for arranging a new image in the composite image, and an image arranged in the composite image. It may be a user operation to remove from the synthesized image.

  The processes of the first luminance determination unit and the second luminance determination unit will be described in detail.

For each light source, the first luminance determining unit determines the first luminance of the light source according to the feature amount acquired for the light source. The first luminance is determined in accordance with the set third correspondence (correspondence between the feature amount and the target luminance).
Note that the third correspondence may or may not be determined in advance by a manufacturer or the like. For example, the third correspondence relationship may be determined according to a user operation, a plurality of input image data, an installation environment of the image display device, and the like.

Next, for each light source, the first luminance determination unit changes the previous first luminance of the light source by a first change amount according to the difference between the current first luminance of the light source and the previous first luminance. The current first luminance of the light source is corrected to the value. The first change amount is determined according to the set fourth correspondence relationship (correspondence relationship between the target luminance difference and the first change amount).
Note that the fourth correspondence relationship may or may not be determined in advance by the manufacturer or the like. For example, the fourth correspondence relationship may be determined according to a user operation, a plurality of input image data, an installation environment of the image display device, and the like.

  And a 1st determination part outputs the 1st brightness | luminance after correction | amendment of each light source to a backlight control part.

  For each light source, the second luminance determining unit determines the second luminance of the light source according to the feature amount acquired for the light source. The second luminance is determined according to the set third correspondence relationship.

Next, the second luminance determination unit changes, for each light source, the previous second luminance of the light source by a second change amount corresponding to the difference between the current second luminance of the light source and the previous second luminance. The current second luminance of the light source is corrected to the value. The second change amount is determined in accordance with the set fifth correspondence (correspondence between the target luminance difference and the second change amount).
Note that the fifth correspondence relationship may or may not be predetermined by a manufacturer or the like. For example, the fifth correspondence relationship may be determined according to a user operation, a plurality of input image data, an installation environment of the image display device, and the like.

  And a 2nd determination part outputs the 2nd brightness | luminance after correction | amendment of each light source to a backlight control part.

FIG. 14 shows an example of the fourth correspondence relationship and the fifth correspondence relationship. FIG. 14 shows the absolute value of the change amount. If the current target brightness is greater than the previous target brightness, a positive value is used as the change amount. If the current target brightness is less than the previous target brightness, a negative value is used as the change amount. Is done. In FIG. 14, the symbol A indicates the fourth correspondence relationship, and the symbol B indicates the fifth correspondence relationship.
As shown in FIG. 14, the maximum value DB of the absolute value of the second change amount can be smaller than the maximum value DA of the absolute value of the first change amount. As a result, the target luminance whose temporal change is suppressed compared to the first luminance can be determined as the second luminance.
As a result, the temporal change in the light emission luminance of the light source near the boundary can be made slower than that in the non-boundary light source, and the change in display luminance near the boundary can be made difficult to perceive. In addition, the light emission luminance of the light source near the non-boundary can be quickly changed according to the feature amount of the image, and a display image with a wide dynamic range or a display with a high contrast can be quickly obtained in a region away from the boundary. it can.

The fourth correspondence relationship and the fifth correspondence relationship shown in FIG. 14 will be supplemented.
In the fourth correspondence relationship illustrated in FIG. 14, the absolute value of the first change amount linearly increases from 0 to DA as the luminance difference (target luminance difference) from 0 to the threshold Th1 increases. In the fourth correspondence relationship shown in FIG. 14, the absolute value DA of the first change amount is associated with the luminance difference equal to or greater than the threshold Th1.
In the fifth correspondence relationship illustrated in FIG. 14, the absolute value of the second change amount linearly increases from 0 to DB as the luminance difference increases from 0 to the threshold Th2. The threshold value Th2 is smaller than the threshold value Th1. In the fifth correspondence relationship illustrated in FIG. 14, the absolute value DB of the second change amount is associated with the luminance difference equal to or greater than the threshold Th2.
In FIG. 14, the absolute value of the first change amount associated with the luminance difference of 0 or more and the threshold value Th2 or less is equal to the absolute value of the second change amount associated with the luminance difference.

Note that the thresholds Th1 and Th2 may or may not be determined in advance by a manufacturer or the like. For example, at least one of the threshold Th1 and the threshold Th2 may be determined according to a user operation, a plurality of input image data, an installation environment of the image display device, and the like.
The fourth correspondence relationship and the fifth correspondence relationship are not limited to the correspondence relationships shown in FIG. For example, in the fourth correspondence relationship, the absolute value of the first change amount may linearly increase from the lower limit value 0 to the upper limit value M as the luminance difference increases from the minimum value 0 to the maximum value 255. The absolute value of the change amount may increase exponentially as the luminance difference increases. The absolute value of the second change amount may be smaller than the absolute value of the first change amount in the entire range of values that the luminance difference can take.

  As described above, according to the present embodiment, the temporal change of the target luminance of the light source near the boundary is suppressed as compared with the light source near the non-boundary. Thereby, the change of the target state of the light source near the boundary due to the change of the composite image (display target image) can be suppressed as compared with the light sources other than the light source near the boundary. As a result, image quality degradation of the display image caused by performing conventional local dimming control during multi-image display in which a plurality of images are displayed side by side can be suppressed while suppressing a decrease in the dynamic range and contrast of the display image.

  Note that the method for suppressing the temporal change in the target luminance is not limited to the above method. For example, by correcting the current target luminance to the average value of a plurality (predetermined number) of target luminances up to now, it is possible to suppress the time change of the target luminance. Therefore, after determining the target luminance of each light source according to the feature amount, the current target state of the boundary vicinity light source is corrected to the average value of the plurality of target states determined for the boundary vicinity light source to the present. Also good. Even with such a configuration, the temporal change in the target luminance of the light source near the boundary can be suppressed as compared with the light source near the non-boundary.

Note that the light emission luminance of each light source may be controlled using the detection result of the scene change.
For example, when the first image and the second image are moving images, and the scene of the first image and the scene of the second image are switched at the same time, not only the non-boundary light source but also the light emission luminance of the light source near the boundary It may be changed promptly. In other cases, the light emission luminance of each light source may be controlled such that the light emission luminance of the light source near the non-boundary is changed quickly and the light emission luminance of the light source near the boundary is changed gently.

Specifically, when the first image is a moving image, the first detection unit detects a scene change of the first image, and when the second image is a moving image, the scene change of the second image. And a second detector for detecting the image may be provided in the image display device. When the first image and the second image are moving images, and the scene of the first image and the scene of the second image are switched simultaneously, the backlight control unit changes the light source near the boundary other than the light source near the boundary. The target state of each light source may be determined. A scene change can be detected based on a difference in image feature amount (for example, average luminance value) between frames. For example, if the difference in image feature between frames is greater than or equal to a threshold, it is determined that a scene change has occurred, and if the difference in image feature between frames is less than the threshold, a scene change occurs. It can be judged that it is not.

  When the scene of the first image and the scene of the second image are switched at the same time, it is difficult to perceive a change in display luminance near the boundary. Therefore, when the scene of the first image and the scene of the second image are switched at the same time, there is no problem even if the light source near the boundary is regarded as the light source near the boundary. By regarding the boundary light source as a non-boundary light source, it is possible to obtain a display image with a wide dynamic range or a display with high contrast over the entire screen. In addition, it is possible to suppress deterioration in the image quality of the display image due to the influence of the image data before the scene change on the display image after the scene change.

An example in which only the scene of the first image is switched will be described with reference to FIGS. 15 (a) and 15 (b). FIG. 15A shows the operation of the conventional image display apparatus, and FIG. 15B shows the operation of the image display apparatus according to the present embodiment. The upper side of FIGS. 15A and 15B shows a display image, and the lower side of FIG. 15B shows the light emission luminance of each light source.
As shown in FIG. 15A, in the conventional image display device, the black float at the end of the second image (end on the first image side) fluctuates greatly due to the scene change of the first image. End up.
In this embodiment, as shown on the lower side of FIG. 15B, the light emission luminance of the light source near the boundary changes gradually. Therefore, as shown on the upper side of FIG.

<Example 7>
Hereinafter, an image display apparatus and a control method thereof according to Embodiment 7 of the present invention will be described with reference to the drawings.
The configuration of the image display apparatus according to the present embodiment is the same as that of the first to sixth embodiments (FIGS. 1, 7, 9, and 10). In a present Example, the process of a 1st brightness | luminance determination part and a 2nd brightness | luminance determination part differs from Examples 1-6.

The first luminance determining unit acquires a feature amount acquired for each light source from the feature amount acquiring unit, and determines a first representative feature amount representing the feature amount acquired for each light source. The first representative feature amount is a maximum value, a minimum value, an average value, a mode value, an intermediate value, or the like of the feature amount of each light source. Then, the first luminance determining unit determines the first luminance (first representative luminance) from the first representative feature amount by the same method as in the first to sixth embodiments. The first luminance determining unit outputs a first representative luminance as the first luminance of each light source. The first representative luminance is output to the backlight control unit.
The method for determining the first representative luminance is not limited to the above method. For example, the 1st brightness | luminance of each light source may be determined by the method similar to Examples 1-6. Then, the maximum value, the minimum value, the average value, the mode value, the intermediate value, and the like of the first luminance of each light source may be determined as the first representative luminance.

The second luminance determination unit acquires the feature amount acquired for each light source from the feature amount acquisition unit. The second luminance determination unit detects a priority light source from the plurality of light sources. Then, the second luminance determining unit determines the feature amount (first representative feature amount) acquired for the priority light source by the same method as in the first to sixth embodiments. The second luminance determining unit outputs a second representative luminance as the second luminance of each light source. The second representative luminance is output to the backlight control unit.
When there are a plurality of priority light sources, the second luminance determination unit determines a second representative feature amount that represents the feature amount acquired for each priority light source. The second representative feature amount is a maximum value, a minimum value, an average value, a mode value, an intermediate value, or the like of the feature amount of each priority light source. The second representative feature amount represents the feature of the priority image. And the 2nd brightness | luminance determination part is the 2nd by the method similar to Examples 1-6.
A second luminance (second representative luminance) is determined from the representative feature amount.
Note that the method of determining the second representative luminance when there are a plurality of priority light sources is not limited to the above method. For example, the 2nd brightness | luminance of each priority light source may be determined by the method similar to Examples 1-6. Then, the maximum value, the minimum value, the average value, the mode value, the intermediate value, and the like of the second luminance of each light source may be determined as the second representative luminance.

The priority light source is, for example, a light source arranged in a divided area (priority area) where only the priority image that is one of the first image and the second image is displayed. In this embodiment, when one of the first image and the second image is a still image and the other is a moving image, the second luminance determination unit selects the still image as a priority image. When both the first image and the second image are moving images, the second luminance determining unit selects the first image as a priority image. Even when both the first image and the second image are still images, the second luminance determination unit selects the first image as a priority image.
The priority area can be detected based on the display area information (image display area of the priority image) output from the display area setting unit.
Whether an image is a moving image or a still image can be determined from a difference in image feature between frames. For example, when the feature amount of an image between frames changes, it can be determined that the image is a moving image, and when the feature amount of an image between frames does not change, the image is a still image. Judgment can be made.

Note that at least one of the process of selecting a priority image, the process of detecting a priority area, and the process of detecting a priority light source may be executed by a functional unit other than the second luminance determination unit.
The method for determining whether an image is a moving image or a still image is not limited to the above method. For example, when additional information indicating whether the input image is a moving image or a still image is added to the input image data (the header portion of the input image data), the input image is converted using the additional information. It may be determined whether the image is a moving image or a still image.
Note that the priority image selection method is not limited to the above method. For example, one of the first image and the second image may be selected as the priority image in response to a user operation. Of the first image and the second image, the image operated (selected) by the user may be selected as the priority image. For example, the image display device may acquire selection information representing an image operated by the user from the outside. Then, the second luminance determination unit may select the image represented by the selection information as the priority image.

In addition, the acquisition method of a 2nd representative feature-value is not restricted to the said method. For example, the second representative feature amount may be acquired from image data representing a priority image.
Note that the second representative feature amount is not limited to the feature amount. For example, the second representative feature quantity may be a histogram of pixel values (or luminance values) of the entire priority image or a representative value.
Note that the priority area is not limited to the divided area. For example, at least a divided area where the priority image is displayed may be detected as the priority area. A divided area in which the priority image is displayed and the display size of the priority image is larger than the display sizes of all other images may be detected as the priority area.

  As described above, in this embodiment, the second luminance based on the second representative feature amount representing the feature of the priority image is obtained as the second luminance of each light source. Therefore, in this embodiment, the light emission luminance of the light source near the boundary is controlled based only on the feature amount of the priority image. The light emission luminance of the light source near the boundary is controlled to the second luminance based on the second representative feature amount representing the feature of the priority image.

As described above, according to the present embodiment, the light emission luminance of the light source near the boundary is controlled based only on the feature amount of the priority image. Thereby, it is possible to suppress the light emission luminance of the light source near the boundary from being changed due to a change in an image other than the priority image. As a result, it can suppress that the display brightness | luminance in the vicinity of a boundary changes with the change of images other than a priority image. For example, it is possible to suppress the display luminance at the end of the priority image (the end on the side where another image is arranged) from being changed due to a change in an image other than the priority image.

  As mentioned above, although the preferable Example of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and change are possible within the range of the summary. Moreover, the structure demonstrated in Examples 1-7 can be used in combination with each other. Therefore, it is easily conceivable by those skilled in the art to construct a new apparatus by appropriately combining various techniques in the above-described embodiments, and apparatuses having such various combinations are also within the scope of the present invention. Belongs.

For example, as shown in FIG. 16, when the difference in brightness between the first image and the second image is small, the temporal change in the emission luminance of the light source near the boundary may be suppressed by the method of the sixth embodiment. When the brightness difference between the first image and the second image is large, the controllable range of the light emission luminance of the light source near the boundary may be reduced by the method of the first embodiment.
According to such a configuration, when both the first image and the second image are dark, it is possible to reduce a sense of discomfort in the display image by controlling only the light emission luminance of the light source near the boundary to a high value. Further, when the difference in brightness between the first image and the second image is large, the display image data in the vicinity of the boundary is reduced by reducing the controllable range of the light emission luminance of the light source in the vicinity of the boundary by the method of the first embodiment. It can be suppressed that the pixel value of is limited to the upper limit value. As a result, it is possible to suppress a decrease in the maximum value of display luminance in the vicinity of the boundary.

<Other examples>
The present invention can also be implemented by a system (or a device such as a CPU or MPU) of a system or apparatus that implements the functions of the above-described embodiments by reading and executing a program recorded in a storage device. The present invention can also be implemented by a method comprising steps executed by a computer of a system or apparatus that implements the functions of the above-described embodiments by reading and executing a program recorded in a storage device, for example. . For this purpose, the program is stored in the computer from, for example, various types of recording media that can serve as the storage device (ie, computer-readable recording media that holds data non-temporarily). Provided to. Therefore, the computer (including devices such as CPU and MPU), the method, the program (including program code and program product), and the computer-readable recording medium that holds the program non-temporarily are all present. It is included in the category of the invention.

103, 303: Feature amount acquisition unit 104: First luminance determination unit 105: Second luminance determination unit 106, 306: Backlight control unit 108: Backlight module 109: Liquid crystal panel 310: Feature amount comparison unit

Claims (8)

A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
Control means for controlling a light emission state that is at least one of a light emission luminance and a light emission color of each light source based on a feature amount of the display image in a region of the screen corresponding to each light source;
With
When the display image is an image arranged in a region where the first image and the second image are different from each other,
A change in the light emission state of the target light source corresponding to a region including a boundary between the first image and the second image and a region in the vicinity thereof in the screen among the plurality of light sources,
In the image display device that is controlled so as to be suppressed compared to a change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources,
First acquisition means for acquiring a first feature amount that is a feature amount of the first image;
Second acquisition means for acquiring a second feature amount that is a feature amount of the second image;
Further comprising
The control means is configured such that a change in a light emission state of the target light source due to a change in the display image is significantly suppressed as a difference between the first feature amount and the second feature amount is larger than that of the non-target light source. To control the light emission state of each light source,
An image display device characterized by that. A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
Control means for controlling a light emission state that is at least one of a light emission luminance and a light emission color of each light source based on a feature amount of the display image in a region of the screen corresponding to each light source;
With
When the display image is an image arranged in a region where the first image and the second image are different from each other,
Of the plurality of light sources, the screen includes a boundary between the first image and the second image.
The change in the light emission state of the target light source corresponding to the region and the region in the vicinity thereof,
In the image display device that is controlled so as to be suppressed compared to a change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources,
First detection means for detecting a scene change of the first image when the first image is a moving image;
Second detection means for detecting a scene change in the second image when the second image is a moving image;
Further comprising
When the first image and the second image are moving images and the scene of the first image and the scene of the second image are switched simultaneously, the control means sets the target light source as the non-target. Consider the light source and control the light emission state of each light source.
An image display device characterized by that. First acquisition means for acquiring a first feature amount that is a feature amount of the first image;
Second acquisition means for acquiring a second feature amount that is a feature amount of the second image;
Further comprising
The control means is configured such that a change in a light emission state of the target light source due to a change in the display image is significantly suppressed as a difference between the first feature amount and the second feature amount is larger than that of the non-target light source. To control the light emission state of each light source,
The image display device according to claim 2. First storage means for storing information representing a first correspondence relationship that is a correspondence relationship between a feature amount and a light emission state;
A second storage unit that stores information representing a second correspondence relationship that is a correspondence relationship between the feature amount and the light emission state, and the range of the light emission state associated with the feature amount is narrower than the first correspondence relationship;
Further comprising
The control means includes
Controlling a light emission state of the non-target light source based on the feature amount of the region corresponding to the non-target light source and the first correspondence relationship;
Controlling the light emission state of the target light source based on the feature amount of the region corresponding to the target light source and the second correspondence relationship;
The image display apparatus according to any one of claims 1 3, characterized in that. The control means includes
The light emission state of each light source is controlled periodically,
First change of current emission state of the non-target light source according to a difference between a current feature amount of the region corresponding to the non-target light source and a feature amount of the region corresponding to the non-target light source in the previous cycle Control with a value that changes the light emission state in the previous period of the non-target light source by the amount,
The current light emission state of the target light source is the second change amount according to the difference between the current feature amount of the region corresponding to the target light source and the feature amount of the region corresponding to the target light source in the previous cycle. Control with the value that changed the light emission state in the previous cycle of the target light source,
The maximum value that can be taken by the absolute value of the second change amount is smaller than the maximum value that can be taken by the absolute value of the first change amount,
The image display apparatus according to any one of claims 1 3, characterized in that. A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
A method for controlling an image display device comprising:
A control step of controlling a light emission state that is at least one of a light emission luminance and a light emission color of each light source based on a feature amount of the display image in a region of the screen corresponding to each light source;
In the control step, when the display image is an image arranged in a region where the first image and the second image are different from each other,
A change in the light emission state of the target light source corresponding to a region including a boundary between the first image and the second image and a region in the vicinity thereof in the screen among the plurality of light sources,
In the control method of the image display device that controls to be suppressed as compared with the change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources,
A first acquisition step of acquiring a first feature amount that is a feature amount of the first image;
A second acquisition step of acquiring a second feature amount that is a feature amount of the second image;
Further comprising
In the control step, the change in the light emission state of the target light source due to the change in the display image is more suppressed as the difference between the first feature amount and the second feature amount is larger than that of the non-target light source. To control the light emission state of each light source,
And a control method for the image display device. A light emitting means having a plurality of light sources capable of individually controlling light emission;
Display means for transmitting light emitted from the light emitting means and displaying an image on a screen based on a display image;
A method for controlling an image display device comprising:
A control step of controlling a light emission state that is at least one of the light emission luminance and the light emission color of each light source based on the feature amount of the display image in the area of the screen corresponding to each light source
Have
In the control step, when the display image is an image arranged in a region where the first image and the second image are different from each other,
A change in the light emission state of the target light source corresponding to a region including a boundary between the first image and the second image and a region in the vicinity thereof in the screen among the plurality of light sources,
In the control method of the image display device that controls to be suppressed as compared with the change in the light emission state of the non-target light source that is not the target light source among the plurality of light sources,
A first detection step of detecting a scene change of the first image when the first image is a moving image;
A second detection step of detecting a scene change of the second image when the second image is a moving image;
Further comprising
In the control step, when the first image and the second image are moving images, and the scene of the first image and the scene of the second image are switched simultaneously, the target light source is set to the non-target. Consider the light source and control the light emission state of each light source.
And a control method for the image display device. The program for making a computer perform each step of the control method of the image display apparatus of Claim 6 or 7 .

Images