Display device and display device control method

Abstract

To provide a display that can appropriately adjust the luminance of a predetermined object included in a display image, and a method for controlling a display.SOLUTION: A display according to an aspect of the present invention comprises a control section that controls a display unit displaying an image by using light emitted from a light emission section based on an input image signal input from the outside. The control section includes an object information acquisition section that acquires information determining whether a predetermined object is included in a display image. The control section adjusts the brightness of the display unit on condition that the predetermined object is included in the display image.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a display device and a method for controlling the display device. [Background technology]

[0002] For example, Patent Document 1 discloses an image display device that includes a display unit that displays an input image signal, a light source that illuminates the display unit, a control unit that controls the display unit and the light source, and a color judgment unit that judges the color of the input image signal.

[0003] For example, colors generally known as memory colors are known. Memory colors include skin color, green plants, blue sky, etc., and the clear display of these objects is closely related to image quality. Of these, skin color and green plants are considered to be classified as object colors, while blue sky is considered to be classified as luminous colors.

[0004] The above-mentioned image display device detects relatively bright areas (light-emitting areas) from the brightness distribution of the image and enhances the display brightness of the light-emitting areas by stretching and increasing the brightness of the light source. In this case, a color judgment unit is used to not enhance the brightness of skin color or the green color of plants (object color) even if it is a light-emitting area, but to enhance the brightness of the blue color of the sky (light-emitting color) even if it is a non-light-emitting area. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-046254 Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned display device (image display device), for example, the brightness of the light source is adjusted by determining the color of a pixel. However, even if the color of a pixel is skin color, for example, the object represented by the pixel is not necessarily a face. Therefore, the brightness of an object that does not affect the image quality is changed, which may cause an unnatural appearance in the displayed image.

[0007] Therefore, an object of the present invention is to provide a display device and a method for controlling the display device that can adjust the brightness of a predetermined object included in a displayed image to an appropriate level, for example. [Means for solving the problem]

[0008] A display device according to one aspect of the present invention includes a control unit that controls a display unit that displays an image by emitting light from a light-emitting unit based on an input image signal input from outside, and the control unit includes an object information acquisition unit that acquires information determining whether or not a specified object is included in the displayed image, and the control unit adjusts the brightness of the display unit on the condition that the specified object is included in the displayed image.

[0009] A control method for a display device according to one aspect of the present invention controls a display unit that displays an image by emitting light from a light-emitting section based on an input image signal input from outside, obtains information determining whether or not a specified object is included in the displayed image, and adjusts the brightness of the display unit on the condition that the specified object is included in the displayed image. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating a display system. [Figure 2] FIG. 2 is a block diagram showing a hardware configuration of the display device. [Figure 3] FIG. 2 is a block diagram showing a hardware configuration of a server device. [Figure 4A] 10 is an example of an image used in the calculation process of the average brightness level. [Figure 4B] FIG. 10 is a diagram showing an example of the luminance level of the light-emitting part for each area in gray scale. [Figure 4C] FIG. 10 is a diagram illustrating an example of the luminance level of a light-emitting unit for each area. [Figure 4D] 10 is a graph showing the relationship between the brightness level of each area and the average brightness level of the display area. [Figure 5A] FIG. 4D is a diagram showing the gradation values ​​of a plurality of pixels in one area of ​​FIG. 4C. [Figure 5B] FIG. 5B is a diagram showing the luminance levels of light-emitting parts in the area shown in FIG. 5A. [Figure 5C] 5B is a diagram showing the results of calculating the gradation values ​​when displaying each pixel shown in FIG. 5A. FIG. [Figure 6] 4 is an example of a first control curve showing the relationship between the average brightness level and the peak brightness. [Figure 7A] FIG. 10 is a diagram illustrating an example of a display image. [Figure 7B] FIG. 7B is a diagram showing a second control curve used for the display image shown in FIG. 7A. [Figure 8A] FIG. 10 is a diagram showing another example of a display image. [Figure 8B] FIG. 8B is a diagram showing a third control curve used for the display image shown in FIG. 8A. [Figure 9] 10 is an example of a processing flow relating to brightness adjustment control of a light-emitting unit by a control unit. [Figure 10] 10 is a modified example of a processing flow relating to brightness adjustment control of a light-emitting unit by a control unit. [Figure 11] FIG. 10 is a diagram showing a first modified example of the display system. [Figure 12] FIG. 10 is a diagram showing a second modified example of the display system. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In this specification and drawings, identical or equivalent elements are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention may be omitted from illustration. Furthermore, the forms of the components shown in the embodiments are merely examples, and the present invention is not limited to these forms.

[0012] An overview of a display system 10 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing the display system 10. As shown in Fig. 1, the display system 10 is configured such that a display device 100 can be connected to a server device 200 via a network NW.

[0013] The display device 100 is a device that displays an image (video) by performing image processing on an input image (video) signal. The display device 100 is, for example, a television receiver. The display device 100 displays an image (video) by performing image processing on an image (video) signal separated from a broadcast signal or an image (video) signal input from an external device.

[0014] The server device 200 is a device that can generate an object determination model, a light source information determination model, etc., which are used for image recognition and will be described later. The processing related to image recognition in this embodiment may be performed by the display device 100 or the server device 200.

[0015] An overview of the display device 100 will be described with reference to Fig. 2. Fig. 2 is a block diagram showing the hardware configuration of the display device 100.

[0016] The display device 100 includes a control unit 110, a storage unit 120, a communication unit 130, a display unit 140, and a light emitting unit 150.

[0017] The control unit 110 controls the display device 100. The control unit 110 realizes various functions by reading and executing various programs stored in the storage unit 120. The control unit 110 is configured by, for example, one or more CPUs (Central Processing Units). The control unit 110 includes a display control unit 111 that controls the display unit 140 and a brightness control unit 112 that controls the brightness of the light-emitting unit 150.

[0018] The storage unit 120 stores various programs and various data necessary for the operation of the display device 100. The storage unit 120 may be, for example, a non-volatile memory such as an HDD (Hard Disk Drive), or may be configured to include a RAM (Random Access Memory).

[0019] The communication unit 130 is an interface for connecting to and communicating with the network NW. The communication unit 130 controls communication with the server device 200 via the network NW. In this embodiment, the communication unit 130 is connected to the network NW by wired communication, but is not limited to this and may be connected by wireless communication.

[0020] The display unit 140 is, for example, a liquid crystal panel that is illuminated by the light emitting unit 150 and displays an image.

[0021] The light-emitting unit 150 is, for example, a backlight having a plurality of LEDs. The light-emitting unit 150 is a direct-type backlight that is arranged on the rear side of the display unit 140. The light-emitting unit 150 emits light toward the display unit 140.

[0022] In this embodiment, a configuration including the display section 140 and the light-emitting section 150 is referred to as a display unit. As the display unit, the display section 140, which is a liquid crystal panel, and the light-emitting section 150, which is a backlight, are used, but the display unit is not limited to this, and for example, a display panel in which self-luminous elements such as OLEDs (Organic Light Emitting Diodes) are arranged may be used.

[0023] An overview of the server device 200 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the hardware configuration of the server device 200.

[0024] The server device 200 includes a control unit 210, a storage unit 220, and a communication unit 230.

[0025] The control unit 210 controls the server device 200. The control unit 210 realizes various functions by reading and executing various programs stored in the storage unit 220. The control unit 210 is configured by, for example, one or more CPUs (Central Processing Units) or the like.

[0026] The storage unit 220 stores various programs and various data necessary for the operation of the server device 200. The storage unit 220 is, for example, a non-volatile storage unit such as a flash memory. The storage unit 220 stores, for example, an object determination model (described later), an object DB 220a for generating the object determination model, a light source information determination model (described later), a light source information DB 220b for generating the light source information determination model, and the like. Each model includes information such as a program algorithm and parameters used by the program, which are obtained through machine learning (described later).

[0027] The communication unit 230 is an interface for connecting to and communicating with the network NW. The communication unit 230 controls communication with the display device 100 via the network NW. In this embodiment, the communication unit 230 is connected to the network NW by wired communication, but is not limited to this and may be connected by wireless communication.

[0028] An example of the calculation process of the average luminance level (APL: Average Picture Level) of the light-emitting unit 150 by the luminance control unit 112 will be described using Fig. 4. Fig. 4A is an example of an image used in the calculation process of the average luminance level. Fig. 4B is a diagram showing an example of the luminance level of the light-emitting unit 150 for each area in grayscale. Fig. 4C is a diagram showing an example of the luminance level of the light-emitting unit 150 for each area. Fig. 4D is a graph showing the relationship between the luminance level of each area and the average luminance level of the display area.

[0029] The brightness control unit 112 divides the display area of ​​the display unit 140, which displays an image, into a predetermined number of areas, and controls the light emission brightness of the light emitting unit 150 (backlight LED) corresponding to each of the divided areas for each area. At least one LED constituting the light emitting unit 150 is disposed in each area.

[0030] Based on the input video signal, the brightness control unit 112 divides one frame of image into a plurality of predetermined areas and extracts the maximum gradation value of the image signal for each divided area. In this embodiment, the maximum gradation value of the image signal is extracted, but this is not limiting, and other statistical values ​​such as the average gradation value of the image signal may also be extracted.

[0031] For example, the luminance control unit 112 divides the image shown in Fig. 4A into a plurality of predetermined areas. The luminance control unit 112 determines the luminance level of the light-emitting unit 150 for each area according to the maximum gradation value extracted for each area. The luminance level of the light-emitting unit 150 for each area at this time is shown in grayscale in Fig. 4B. In bright areas where the gradation of the image signal is high, the luminance level of the light-emitting unit 150 is increased to provide a bright display.

[0032] FIG. 4C shows an example of the state when the maximum gradation value of each area of ​​one frame is extracted. In FIG. 4C, for the sake of simplicity, the screen of one frame is divided into eight areas (areas <1> ~Area <8> ) FIG. 4C shows the brightness level of each area, and FIG. 4D shows the brightness level of each area and the average brightness level of the display area. In this embodiment, the brightness level of the light-emitting unit 150 of the corresponding area is calculated from the maximum gradation value of each area. The brightness level can be indicated, for example, by the drive duty of the LEDs that make up the light-emitting unit 150. In this case, the maximum brightness level is 100%.

[0033] When determining the brightness level of the light-emitting unit 150 in each area, in a dark area where the maximum gradation value is low, the brightness level is lowered to reduce the brightness of the light-emitting unit 150. For example, when the gradation value of an image is expressed as 8-bit data of 0-255, if the maximum gradation value is 128, the light-emitting unit 150 is set to (1 / (255 / 128)) 2.2 =0.217 times (21.7%). Note that the above-described method for calculating the brightness level is an example, but basically the brightness level of each area is calculated using a predetermined arithmetic expression so that the brightness of light-emitting unit 150 is not reduced in bright, high-gradation areas, but is reduced in dark, low-gradation areas.

[0034] The luminance levels of the light-emitting unit 150 for each area calculated from the maximum gradation value of the image signal are then averaged to calculate the average luminance level of the light-emitting unit 150 for one frame. In this embodiment, the average luminance level is the average luminance level shown in Fig. 4D. The average luminance level is an example of an index related to the brightness of a displayed image.

[0035] The calculation process for the average brightness level of light-emitting unit 150 will be described in more detail with reference to Figure 5. Figure 5A is a diagram showing the gradation values ​​of multiple pixels in one area of ​​Figure 4C. Figure 5B is a diagram showing the brightness levels of the light-emitting unit in the area shown in Figure 5A. Figure 5C is a diagram showing the results of calculating the gradation values ​​when displaying each pixel shown in Figure 5A.

[0036] When determining the brightness level of the light-emitting unit 150 in each area, the brightness level is lowered in dark areas where the maximum gradation value is low, thereby reducing the brightness of the light-emitting unit 150. The actual brightness level of each area is determined so that the displayed gradation is displayed accurately and the LED duty is as low as possible. Although it is desired to lower the LED duty as much as possible in each area, it is necessary to display the displayed gradation accurately without crushing it. Therefore, the LED duty is set so that the maximum gradation in the area can be displayed and the LED duty is as low as possible, and the display control unit 111 sets the gradation of the display unit 140 based on this.

[0037] As an example, a case will be described in which the gradation values ​​of an image are expressed by 8-bit data ranging from 0 to 255, and the gradation values ​​of multiple pixels in one area of ​​FIG. 4C are shown in FIG. 5A. Here, it is assumed that nine pixels correspond to one area. In the pixel group shown in FIG. 5A, the maximum gradation value is 128, and in this case, as shown in FIG. 5B, the luminance level of the light-emitting unit 150 corresponding to that area is set to (1 / (255 / 128)). 2.2 =0.217 times (21.7%).

[0038] Then, display control unit 111 calculates the gradation value for each pixel on display unit 140, taking into account the brightness level of the area that includes that pixel. For example, if the displayed gradation value is 96, then 96 / (128 / 255)=192, and therefore the pixel can be expressed using the gradation value 192. Similarly, the results of calculating the gradation values ​​when displayed for each pixel in FIG. 5A are shown in FIG. 5C.

[0039] The luminance stretch control by the luminance control unit 112 will be described with reference to Fig. 6. Fig. 6 is an example of a first control curve showing the relationship between the average luminance level and the peak luminance. The first control curve shown in Fig. 6 is an example of a control curve used for normal stretch control.

[0040] The luminance control unit 112 stretches the luminance of the light-emitting unit 150 based on the peak luminance determined according to the average luminance level of the light-emitting unit 150. The peak luminance is the maximum screen luminance that can be achieved in the display area, and more specifically, the screen luminance after stretching at the maximum gradation value. For example, in the case of 8-bit representation, a pixel with 255 gradation has the highest screen luminance within the display area, and is the maximum screen luminance (peak luminance) that can be achieved in the display area. The reference luminance that is the basis for stretching is, for example, when the screen luminance is approximately 450 (cd / m) at the maximum gradation value. 2 The reference luminance is not limited to this example and can be determined as appropriate.

[0041] The luminance control unit 112 determines the peak luminance from the average luminance level of the light-emitting unit 150. In the first control curve used for normal stretch control, the peak luminance when the light-emitting unit 150 is fully lit is approximately 450 (cd / m 2 ) As the average brightness level decreases, the peak brightness increases. When the average brightness level is in the range of 0 to 15%, the peak brightness value is the largest, and the maximum screen brightness at this time is approximately 2000 (cd / m 2 ) In other words, when the average brightness level is in the range of 0 to 15%, the maximum possible screen brightness is approximately 450 (cd / m 2 ) compared to about 2000 (cd / m 2 ) will be stretched to

[0042] The range of 0 to 15% is a relatively low range of average brightness levels. In this way, when the screen is dark overall, the average brightness level is low, and there are some high-gradation peaks, the maximum brightness is about 2000 (cd / m 2 ) the brightness of the light-emitting unit 150 is stretched until it reaches a certain level. The reason why the degree of stretching of the brightness of the light-emitting unit 150 is smaller at higher average brightness levels is that if the brightness of the light-emitting unit 150 is made too high on an originally bright screen, it may be perceived as dazzling, so the degree of stretching is suppressed.

[0043] In the above configuration, the luminance control unit 112 stretches the luminance of the light-emitting unit 150 according to the curve in Fig. 6. Here, the average luminance level changes according to the maximum gradation value detected for each area of ​​the image, and the amount of luminance stretch changes according to the average luminance level.

[0044] The functional configuration of the brightness control unit 112 will be described with reference to Fig. 2. As shown in Fig. 2, the brightness control unit 112 includes an object determination unit 112a that determines whether or not a predetermined object is included in the display image, a brightness determination unit 112b that determines whether or not an index related to the brightness of the display image is equal to or less than a predetermined threshold, and a light source information determination unit 112c that determines whether or not information related to a light source is included in the display image.

[0045] The object determination unit 112a determines whether or not a predetermined object is included in the display image. The predetermined object is an object that affects the video (image) quality. The predetermined object includes, for example, an object that is classified as an object color among objects indicated by memory colors. Examples of the predetermined object include a face, a plant (green of vegetation), and food.

[0046] The object determination unit 112a determines whether or not a predetermined object is included in a display image based on a trained object determination model. The object determination model is a model for determining whether or not a predetermined object is included in a display image.

[0047] In this embodiment, the object determination model is stored in the storage unit 220 of the server device 200. The object determination model is generated by executing machine learning using an object DB 220a stored in the storage unit 220. The object DB 220a stores a plurality of teacher data that are correct answer data indicating a predetermined object. To generate the object determination model, for example, a publicly known algorithm such as deep learning, which is a publicly known technology, can be used.

[0048] The brightness control unit 112 acquires the object determination model from the server device 200 via the communication unit 130 and determines whether or not a predetermined object is included in the display image. The object determination model is stored in the storage unit 220 of the server device 200, but is not limited to this, and may be stored in the storage unit 120 of the display device 100.

[0049] The brightness determination unit 112b determines whether an index relating to the brightness of the display image is equal to or less than a predetermined threshold. In this embodiment, for example, the average brightness level of the light-emitting unit 150 is used as the index relating to the brightness of the display image. The brightness determination unit 112b determines, for example, whether the average brightness level of the light-emitting unit 150 is equal to or less than a predetermined threshold (20%).

[0050] The index relating to the brightness of the display image is not limited to the average luminance level of the light-emitting section 150, and for example, the average luminance value of the light-emitting section 150 may be used.

[0051] The light source information determination unit 112c determines whether or not the display image includes information about the light source. Information about the light source refers to, for example, information about the light source or the light emitted from the light source. Light sources include, for example, artificial light sources such as fluorescent lights and non-artificial light sources such as the moon.

[0052] The light source information determination unit 112c determines whether or not the display image contains information about the light source based on a learned light source information determination model. The light source information determination model is a model for determining whether or not the display image contains information about the light source.

[0053] In this embodiment, the light source information determination model is stored in the storage unit 220 of the server device 200. The light source information determination model is generated by performing machine learning using a light source information DB 220b stored in the storage unit 220. The light source information DB 220b stores teacher data (reference data) that is correct data indicating information related to the light source. To generate the light source information determination model, for example, a known algorithm such as deep learning, which is a known technology, can be used.

[0054] Furthermore, the light source information determination model can determine whether or not the displayed image contains information about an artificial light source. In this case, the light source information determination model is generated by performing machine learning using training data that is correct data indicating an artificial light source such as a fluorescent lamp. Similarly, the light source information determination model can determine whether or not the displayed image contains information about a non-artificial light source. In this case, the light source information determination model is generated by performing machine learning using training data that is correct data indicating a non-artificial light source such as the moon.

[0055] The light source information determination model can also determine whether the light included in the display image is emitted from an artificial light source. In this case, the light source information determination model estimates the spectral distribution from the luminance value of the display image to determine whether the light included in the display image is emitted from an artificial light source.

[0056] In addition to the above-described methods, a method of determining whether light included in a display image is irradiated from an artificial light source can also be considered, for example, a method of estimation based on the scene of the display image determined from a combination of multiple objects included in the display image. In this case, the light source information determination model is generated by performing machine learning using training data (reference data) that is ground truth data indicating the scene of the display image. For example, if objects such as a television, sofa, or kitchen are detected in the display image, it is determined to be an indoor scene. On the other hand, if objects such as a car or traffic lights are detected in the display image, it is determined to be an outdoor scene. If the light source information determination model determines that the display image is an indoor scene, it estimates that the light included in the display image is irradiated from an artificial light source. Similarly, if the light source information determination model determines that the display image is an outdoor scene, it estimates that the light included in the display image is irradiated from a natural light source.

[0057] The luminance control unit 112 acquires the light source information determination model from the server device 200 via the communication unit 130 and determines whether or not the display image contains information about a light source. The luminance control unit 112 may also determine whether or not the display image contains information about an artificial light source. The light source information determination model is stored in the storage unit 220 of the server device 200, but may also be stored in the storage unit 120 of the display device 100.

[0058] The following describes the brightness adjustment control of the light-emitting unit 150 by the brightness control unit 112.

[0059] The luminance control unit 112 adjusts the brightness of the light-emitting unit 150 on the condition that the object determination unit 112a has determined that the display image includes a predetermined object. When it has been determined that the display image includes a predetermined object, stretching the luminance of the light-emitting unit 150 according to the first control curve shown in Fig. 6 would excessively brighten faces, plants, food, and the like, which have a significant impact on image quality, and would likely create an unnatural feeling in the displayed image. Therefore, the luminance control unit 112 adjusts the brightness of the light-emitting unit 150 by lowering the peak luminance determined by the first control curve on the condition that the display image includes a predetermined object.

[0060] In this case, the brightness control unit 112 preferably reduces the peak brightness when the object determination unit 112a determines that the display image contains a predetermined object and the brightness determination unit 112b determines that the brightness index of the display image is equal to or lower than a predetermined threshold (e.g., 20%). In the brightness stretch control of the light-emitting unit 150 performed according to the first control curve shown in FIG. 6, the lower the average brightness level of the light-emitting unit 150 (particularly, the range of the average brightness level from 0 to 15%), the greater the amount of brightness stretch. Therefore, by reducing the peak brightness only when the brightness index of the display image is determined to be equal to or lower than the predetermined threshold, i.e., when the amount of brightness stretch is large, it is possible to effectively prevent faces, plants, food, and the like, which have a significant impact on image quality, from becoming excessively bright. This allows for high-quality image (video) representation.

[0061] In addition, when the object determination unit 112a determines that a predetermined object is included in the display image, the brightness control unit 112 may control the brightness of the light-emitting unit 150 to be different depending on whether or not the display image includes information about the light source.

[0062] For example, if it is determined that the display image contains information about the light source, a specific object will be illuminated by light from the light source. Therefore, if the peak luminance is reduced to the same extent as when it is determined that the display image does not contain information about the light source, the brightness of the specific object will be dark even though it is illuminated by light, which is likely to create an unnatural feeling in the display image. Therefore, when it is determined that the display image contains information about the light source, the extent to which the peak luminance is reduced is made less than when it is determined that the display image does not contain information about the light source. This makes it possible to prevent the luminance of faces, plants, food, etc. from becoming too dark even though they are illuminated by light from the light source. Therefore, high-quality image (video) representation can be achieved.

[0063] Furthermore, when the object determination unit 112a determines that a predetermined object is included in the display image, the brightness control unit 112 may control the brightness of the light-emitting unit 150 to be different depending on whether or not the display image includes information about an artificial light source.

[0064] In general, artificial light has a larger wavelength bias than natural light, making it difficult for colors to appear natural. Therefore, if it is determined that a displayed image contains information about an artificial light source, reducing the peak luminance to the same extent as when the displayed image contains information about a non-artificial light source can easily create an unnatural appearance in the displayed image. Therefore, when it is determined that a displayed image contains information about an artificial light source, the extent to which the peak luminance is reduced is less than when it is determined that the displayed image contains information about a non-artificial light source. This effectively prevents the luminance of faces, plants, food, etc. from becoming too dark even when illuminated by light from an artificial light source. Therefore, high-quality image (video) representation can be achieved.

[0065] It should be noted that the brightness control unit 112 adjusts the brightness of the light-emitting unit 150 based on the judgment results of the object judgment unit 112a and the brightness judgment unit 112b, or the judgment results of the object judgment unit 112a and the light source information judgment unit 112c. However, this is not limiting, and for example, the brightness of the light-emitting unit 150 may be adjusted based on the judgment results of the object judgment unit 112a, the brightness judgment unit 112b, and the light source information judgment unit 112c, or the brightness of the light-emitting unit 150 may be adjusted based only on the judgment result of the object judgment unit 112a.

[0066] 7 and 8, an example of brightness adjustment control of the light-emitting unit 150 when the display image includes information about an artificial light source and when the display image includes information about a non-artificial light source will be described below. FIG. 7A shows an example of a display image including information about an artificial light source. FIG. 7B shows a diagram illustrating a second control curve used for the display image shown in FIG. 7A. FIG. 8A shows an example of a display image including information about a non-artificial light source. FIG. 8B shows a diagram illustrating a third control curve used for the display image shown in FIG. 8A.

[0067] In the display image shown in FIG. 7A, the brightness control unit 112 determines by the object determination unit 112a that the display image contains a predetermined object (in this embodiment, face A), determines by the brightness determination unit 112b that the index related to the brightness of the display image is equal to or less than a predetermined threshold (in this embodiment, 20%), and determines by the light source information determination unit 112c that the display image contains information related to an artificial light source (in this embodiment, artificial light source I).

[0068] The luminance control unit 112 reduces the peak luminance of the display image shown in FIG. 7A based on the above-mentioned determination result. In this embodiment, the peak luminance is adjusted using the second control curve shown in FIG. 7B. In FIG. 7B, the dashed line represents the first control curve, and the solid line represents the second control curve. The second control curve has approximately the same slope as the first control curve when the average luminance level is in the range of 17 to 100%. The second control curve reduces the peak luminance to approximately 1800 (cd / m) when the average luminance level is in the range of 0 to 17%. 2 ) and it can be seen that the peak brightness is lower than that of the first control curve.

[0069] In the second control curve, the peak luminance is approximately 1800 (cd / m) in the range of average luminance level 0 to 17%. 2 ), but is not limited to this, and may be set within a first brightness range with the peak brightness determined by the first control curve as the upper limit. The first brightness range is, for example, 1800 to 2000 (cd / m 2 ) range.

[0070] In the above configuration, the average brightness level of the light-emitting unit 150 for the display image shown in FIG. 7A is 10%, so the brightness control unit 112 controls the peak brightness to 1800 (cd / m 2 ) The brightness control unit 112 controls the brightness of the light-emitting unit 150 based on the peak brightness. Specifically, the brightness control unit 112 adjusts the brightness of the light-emitting unit 150 corresponding to each area collectively based on the peak brightness determined from the second control curve. In this case, regardless of the area in which a specific object is located, the brightness of the light-emitting unit 150 corresponding to each area is reduced collectively based on the second control curve. This darkens the entire display area, reducing power consumption and saving energy.

[0071] 7A, when it is determined that the display image contains information about an artificial light source (artificial light source I in this embodiment), the peak luminance is reduced. However, the present invention is not limited to this, and the luminance of light-emitting unit 150 may be controlled without reducing the peak luminance by using a peak luminance similar to the first control curve. The second control curve used in this case has approximately the same slope as the first control curve.

[0072] 8A, the brightness control unit 112 determines that the object determination unit 112a determines that the display image contains a predetermined object (in this embodiment, face A), the brightness determination unit 112b determines that the brightness index of the display image is equal to or less than a predetermined threshold (in this embodiment, 20%), and that the display image does not contain information about an artificial light source. In this embodiment, it is assumed that the display image contains information about a non-artificial light source (for example, the moon M), rather than information about an artificial light source.

[0073] The luminance control unit 112 reduces the peak luminance of the display image shown in FIG. 8A based on the above-mentioned determination result. In this embodiment, the peak luminance is determined by the third control curve shown in FIG. 8B. In FIG. 8B, the dashed line represents the first control curve, and the solid line represents the third control curve. The third control curve has a slope that is approximately the same as the first control curve when the average luminance level is in the range of 20 to 100%. The third control curve reduces the peak luminance to approximately 1500 (cd / m) when the average luminance level is in the range of 0 to 20%. 2 ), which shows that the peak brightness is lower than that of the first control curve. Furthermore, the third control curve is set so that the peak brightness is lower than that of the second control curve when the average brightness level is in the range of 0 to 20%.

[0074] In the third control curve, the average brightness level is in the range of 0 to 20%, and the peak brightness is approximately 1500 (cd / m 2), but is not limited to this, and may be set within a second luminance range that is lower than the peak luminance determined by the second control curve. The second luminance range is, for example, 1500 to 1800 (cd / m 2 ) range.

[0075] In the above configuration, the average brightness level of the light-emitting unit 150 for the display image shown in FIG. 8A is 10%, so the brightness control unit 112 controls the peak brightness to 1500 (cd / m 2 ) The brightness control unit 112 controls the brightness of the light-emitting unit 150 based on the peak brightness. The brightness control unit 112 adjusts the brightness of the light-emitting unit 150 corresponding to each area collectively based on the peak brightness determined from the third control curve. In this case, regardless of the area in which a specific object is located, the brightness of the light-emitting unit 150 corresponding to each area is reduced collectively based on the third control curve. This darkens the entire display area, reducing power consumption and saving energy.

[0076] 7 and 8, the luminance control unit 112 adjusts the luminance of the light-emitting unit 150 corresponding to each area collectively using the peak luminance determined from the second control curve or the third control curve, but this is not limiting. For example, the luminance control unit 112 may adjust the luminance of the light-emitting unit 150 using different peak luminances for an area where a predetermined object is located and other areas.

[0077] In this case, in the example shown in Fig. 7, brightness control unit 112 adjusts the brightness of light-emitting unit 150 for an area of ​​the display area where a predetermined object is located based on the peak brightness determined from the second control curve, and adjusts the brightness of light-emitting unit 150 for other areas (areas excluding the predetermined object) based on the peak brightness determined from the first control curve. Similarly, in the example shown in Fig. 8, brightness control unit 112 adjusts the brightness of light-emitting unit 150 for an area of ​​the display area where a predetermined object is located based on the peak brightness determined from the third control curve, and adjusts the brightness of light-emitting unit 150 for other areas (areas excluding the predetermined object) based on the peak brightness determined from the first control curve.

[0078] This effectively reduces the brightness of the area where the predetermined object is located, improving the contrast of the entire image and achieving high-quality image (video) representation. In this case, it is assumed that the object determination unit 112a has acquired position information of the location of the predetermined object in the display area.

[0079] Although brightness control unit 112 uses the second and third control curves to adjust the peak brightness, this is not limiting. Also, the second and third control curves are configured so that the peak brightness is lower than the first control curve in a range where the average brightness level is low, but this is not limiting. For example, the second and third control curves may be configured so that the peak brightness is lower than the first control curve in a range where the average brightness level is 0 to 100%.

[0080] An example of a processing flow relating to the brightness adjustment control of the light-emitting unit 150 by the brightness control unit 112 will be described using Fig. 9. Fig. 9 is an example of a processing flow relating to the brightness adjustment control of the light-emitting unit 150. In the processing flow shown in Fig. 9, it is assumed that the brightness adjustment control of the light-emitting unit 150 is performed for each frame of image, for example.

[0081] In S101, the brightness control unit 112 determines whether or not a predetermined object is included in the display image. If it is determined that the predetermined object is included in the display image, that is, if the answer is Yes in S101, the process proceeds to S102. If it is determined that the predetermined object is not included in the display image, that is, if the answer is No in S101, the process proceeds to S106.

[0082] In S102, the brightness control unit 112 determines whether the index related to the brightness of the display image is equal to or less than a predetermined threshold. If it is determined that the index related to the brightness of the display image is equal to or less than the predetermined threshold, that is, if S102 is Yes, the process proceeds to S103. If it is determined that the index related to the brightness of the display image is not equal to or less than the predetermined threshold, that is, if S102 is No, the process proceeds to S106.

[0083] In S103, the brightness control unit 112 determines whether the display image contains information about an artificial light source. If it is determined that the display image contains information about an artificial light source, that is, if S103 is Yes, the process proceeds to S104. If it is determined that the display image does not contain information about an artificial light source, that is, if S103 is No, the process proceeds to S105.

[0084] In S104, the luminance control unit 112 adjusts the luminance of the light-emitting unit 150 based on the peak luminance adjusted to be within the first luminance range, and the process returns to S101. In S104, the luminance of the light-emitting unit 150 is adjusted using, for example, the second control curve.

[0085] In S105, the luminance control unit 112 adjusts the luminance of the light-emitting unit 150 based on the peak luminance adjusted to be within the second luminance range, and the process returns to S101. In S105, the luminance of the light-emitting unit 150 is adjusted using, for example, the third control curve.

[0086] In S106, the luminance control unit 112 adjusts the luminance of the light-emitting unit 150 based on the normal peak luminance, and the process returns to S101. In S106, the luminance of the light-emitting unit 150 is adjusted using, for example, the first control curve.

[0087] A modified example of the processing flow relating to the brightness adjustment control of the light-emitting unit 150 by the brightness control unit 112 will be described with reference to Fig. 10. Fig. 10 shows a modified example of the processing flow relating to the brightness adjustment control of the light-emitting unit 150. In the processing flow shown in Fig. 10, it is assumed that the brightness adjustment control of the light-emitting unit 150 is performed for each frame of image, for example. In the modified example shown in Fig. 10, it is assumed that the brightness adjustment control of the light-emitting unit 150 is performed using only the object determination unit 112a.

[0088] In S201, the brightness control unit 112 determines whether or not a predetermined object is included in the display image. If it is determined that the predetermined object is included in the display image, that is, if the answer is Yes in S201, the process proceeds to S202. If it is determined that the predetermined object is not included in the display image, that is, if the answer is No in S201, the process proceeds to S203.

[0089] In S202, the luminance control unit 112 adjusts the luminance of the light-emitting unit 150 based on the peak luminance adjusted to be within the first luminance range, and the process returns to S201. In S202, the luminance of the light-emitting unit 150 is adjusted using, for example, the second control curve.

[0090] In S203, the luminance control unit 112 adjusts the luminance of the light-emitting unit 150 based on the normal peak luminance, and the process returns to S201. That is, in S203, the luminance of the light-emitting unit 150 is adjusted using, for example, the first control curve.

[0091] Although the control unit 110 of the display device 100 has the object determination unit 112a, the present invention is not limited to this and the control unit 210 of the server device 200 may have the same. Similarly, although the control unit 110 of the display device 100 has the light source information determination unit 112c, the present invention is not limited to this and the control unit 210 of the server device 200 may have the same.

[0092] A first modified example of the display system 10 will be described with reference to Fig. 11. Fig. 11 is a diagram showing a display system 10a.

[0093] 11, the control unit 210 of the server device 200 includes an object determination unit 210a that determines whether or not a predetermined object is included in the display image, and a light source information determination unit 210b that determines whether or not information related to a light source is included in the display image. The storage unit 220 of the server device 200 stores an object determination model that is a model for determining whether or not a predetermined object is included in the display image, and a light source information determination model that is a model for determining whether or not information related to a light source is included in the display image.

[0094] As shown in FIG. 11, the control unit 110 of the display device 100 includes an object information acquisition unit 112d that acquires information determining whether or not a specified object is included in the displayed image, a brightness determination unit 112b that determines whether or not an index related to the brightness of the displayed image is equal to or less than a specified threshold, and a light source information acquisition unit 112e that acquires information determining whether or not the displayed image includes information related to a light source.

[0095] In the display system 10a shown in Fig. 11, the server device 200 determines whether a display image includes a predetermined object, and determines whether the display image includes information related to a light source. The determination results made by the server device 200 are then transmitted to the display device 100 via the communication unit 230. The object information acquisition unit 112d of the display device 100 acquires the determination results made by the object determination unit 210a from the server device 200 via the communication unit 130. Similarly, the light source information acquisition unit 112e of the display device 100 acquires the determination results made by the light source information determination unit 210b from the server device 200 via the communication unit 130.

[0096] In the above configuration, the display device 100 adjusts the brightness of the light-emitting unit 150 based on the determination results acquired from the server device 200 and the determination result determined by the brightness determination unit 112b.

[0097] As described above, it is sufficient for the control unit 110 of the display device 100 to at least acquire information that determines whether or not a predetermined object is included in the display image, and it is sufficient for the control unit 110 to have the object information acquisition unit 112d. That is, the control unit 110 of the display device 100 does not necessarily need the object determination unit 112a. It is assumed that the object determination unit 112a also serves as the object information acquisition unit 112d. It is also sufficient for the control unit 110 of the display device 100 to at least acquire information that determines whether or not information related to a light source is included in the display image, and it is sufficient for the control unit 110 to have the light source information acquisition unit 112e. That is, the control unit 110 of the display device 100 does not necessarily need the light source information determination unit 112c. It is assumed that the light source information determination unit 112c also serves as the light source information acquisition unit 112e.

[0098] A second modified example of the display system 10 will be described with reference to Fig. 12. Fig. 12 is a diagram showing a display system 10b. The display system 10b is composed of a display device 100 only.

[0099] The memory unit 120 of the display device 100 stores an object determination model, which is a model for determining whether a displayed image contains a specified object, an object DB 120a for generating the object determination model, a light source information determination model, which is a model for determining whether a displayed image contains information about a light source, and a light source information DB 120b for generating the light source information determination model.

[0100] In the above configuration, the object determination unit 112a of the display device 100 determines whether or not a predetermined object is included in the display image based on the object determination model generated by the object DB 120a. The brightness determination unit 112b of the display device 100 determines whether or not an index related to the brightness of the display image is equal to or less than a predetermined threshold. The light source information determination unit 112c of the display device 100 determines whether or not information related to a light source is included in the display image based on the light source information determination model generated by the light source information DB 120b. The brightness control unit 112 adjusts the brightness of the light-emitting unit 150 based on the above-mentioned determination results. As described above, the display system 10b may be composed of only the display device 100.

[0101] The above-described configuration is applied to a display unit including a display section 140 (liquid crystal panel) and a light-emitting section 150 (backlight), but is not limited thereto and can also be applied to a display panel in which self-luminous elements such as OLEDs are arranged. In this case, the display panel serves as both the display section 140 and the light-emitting section 150. As an index of the brightness of the displayed image, an average brightness value obtained by dividing the sum of the brightness values ​​of all pixels constituting the display area by the number of pixels, or an average brightness level which is the ratio of the average brightness value to the maximum brightness value can be used. Then, the brightness of the display unit is adjusted by changing the average brightness value or the peak brightness corresponding to the average brightness level.

[0102] In the above configuration, the display device 100 includes a control unit 110 that controls the display unit, which displays an image by emitting light from the light-emitting unit 150, based on an input image signal input from outside. The control unit 110 includes an object information acquisition unit 112d that acquires information determining whether or not a predetermined object is included in the displayed image. The control unit 110 adjusts the brightness of the display unit (light-emitting unit 150) on the condition that the predetermined object is included in the displayed image. This makes it possible to adjust the brightness of the predetermined object included in the displayed image to an appropriate level, thereby suppressing any sense of incongruity that may occur in the displayed image and achieving high-quality image (video) expression.

[0103] The control unit 110 determines whether an index (average brightness level) related to the brightness of the display image is equal to or less than a predetermined threshold, and if it determines that the index (average brightness level) is equal to or less than the predetermined threshold, adjusts the brightness of the display unit (light-emitting unit 150). This prevents a predetermined object from becoming excessively bright when the brightness of the entire display image is relatively dark, for example. This allows for high-quality image (video) representation.

[0104] The control unit 110 acquires information that determines whether the display image contains information about the light source, and if the display image contains information about the light source, adjusts the brightness of the display unit (light-emitting unit 150). This allows the brightness of a specific object to be adjusted appropriately even if the specific object is illuminated by light from the light source. This makes it possible to achieve high-quality image (video) representation.

[0105] The control unit 110 acquires information indicating whether or not the display image includes information about a light source. If the display image includes information about a light source and the information about the light source is information about an artificial light source, the control unit 110 adjusts the brightness of the display unit to a first state. If the display image includes information about a light source and the information about the light source is not information about an artificial light source, the control unit 110 adjusts the brightness of the display unit to a second state. The control unit 110 darkens the brightness of the display unit in the second state compared to the first state. This allows the brightness of the display unit (light-emitting unit 150) to be adjusted according to the type of light when the display image includes natural light and when the display image includes artificial light, thereby achieving high-quality image (video) representation.

[0106] The control unit 110 adjusts the peak luminance, which is the maximum luminance that can be achieved in the display area of ​​the display unit, to adjust the brightness of the display unit (light emitting unit 150).

[0107] The display unit includes a liquid crystal display panel that displays an image and a backlight that irradiates the liquid crystal display panel with light, and the light emitting section 150 is the backlight.

[0108] The display device 100 is communicably connected to the server device 200. The control unit 110 acquires from the server device 200 information indicating whether or not a predetermined object is included in a display image.

[0109] The control unit 110 determines whether or not a predetermined object is included in the display image. The display device 100 further includes a storage unit 120 that stores an object determination model used when the control unit 110 determines whether or not a predetermined object is included in the display image.

[0110] The control unit 110 determines whether or not a predetermined object is included in a display image. The display device 100 is communicably connected to a server device 200. The control unit 110 acquires, from the server device 200, an object determination model used when determining whether or not the predetermined object is included in a display image.

[0111] The control method of the display device 100 controls the display unit, which displays an image by emitting light from the light-emitting unit 150, based on an input image signal input from outside, obtains information determining whether or not a specified object is included in the displayed image, and adjusts the brightness of the display unit on the condition that the specified object is included in the displayed image.

[0112] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configurations shown in the above-described embodiment can be replaced with configurations that are substantially the same as those shown in the above-described embodiment, that have the same effects, or that can achieve the same purpose. [Explanation of symbols]

[0113] 100 display device, 110 control unit, 112 brightness control unit, 112a object determination unit, 112b brightness determination unit, 112c light source information determination unit, 112d object information acquisition unit, 112e light source information acquisition unit, 120 storage unit, 140 display unit, 150 light emission unit, 200 server device

Claims

1. a control unit that controls a display unit that displays an image by emitting light from a light emitting unit based on an input image signal input from an external device; the control unit includes an object information acquisition unit that acquires information determining whether a display image displayed by the display unit includes a predetermined object, and a light source information acquisition unit that acquires information determining whether the display image includes information about a light source different from the predetermined object, the predetermined object is an object classified as an object color among objects indicated by memory colors, the control unit, on condition that the predetermined object is included in the display image, reduces a peak luminance determined in accordance with an average luminance level of the light-emitting unit in a display area of ​​the display unit to a level lower than the peak luminance in a case where the predetermined object is not included; The peak luminance is the maximum luminance that can be achieved in the display area, When the display image includes information about the specified object and the light source, the control unit reduces the peak brightness determined according to the average brightness level to a level lower than the peak brightness when the display image does not include the specified object, and increases the peak brightness to a level higher than the peak brightness when the display image includes the specified object and does not include information about the light source.

2. The display device according to claim 1, wherein the control unit determines whether the average brightness level is equal to or lower than a predetermined threshold, and only when it is determined that the average brightness level is equal to or lower than the predetermined threshold, reduces the peak brightness determined according to the average brightness level to a level lower than the peak brightness when the predetermined object is not included, on the condition that the predetermined object is included in the displayed image.

3. The control unit When the display image includes information about the predetermined object and the light source, and the information about the light source is information about an artificial light source, adjusting the peak luminance determined according to the average luminance level to a first mode; When the display image includes information about the predetermined object and the light source and the information about the light source is not information about an artificial light source, the peak luminance determined according to the average luminance level is adjusted to a second mode; The display device according to claim 1 or 2, wherein the control unit reduces the peak luminance in the second mode more than in the first mode.

4. The display unit a liquid crystal display panel for displaying the image; a backlight that irradiates the liquid crystal display panel with light, The display device according to claim 1 , wherein the light emitting section is the backlight.

5. Communicatively connected to the server device, The display device according to claim 1 , wherein the control unit acquires the information indicating whether the predetermined object is included in the display image from the server device.

6. The display device according to claim 1 , wherein the control unit determines whether the predetermined object is included in the display image.

7. The display device according to claim 6 , further comprising a storage unit that stores an object determination model used when the control unit determines whether the predetermined object is included in the display image.

8. Communicatively connected to the server device, The display device according to claim 6 , wherein the control unit acquires, from a server device, an object determination model used when determining whether the predetermined object is included in the display image.

9. A display unit that displays an image by emitting light from a light-emitting portion is controlled based on an input image signal input from an external device; acquiring information indicating whether a predetermined object is included in a display image displayed by the display unit; acquiring information indicating whether the display image includes information about a light source different from the predetermined object; the predetermined object is an object classified as an object color among objects indicated by memory colors, On the condition that the predetermined object is included in the display image, a peak luminance determined according to an average luminance level of the light-emitting section in a display area of ​​the display unit is reduced to a value lower than the peak luminance in a case where the predetermined object is not included; The peak luminance is the maximum luminance that can be achieved in the display area, A control method for a display device, wherein, when the display image includes information about the specified object and the light source, the peak luminance determined according to the average luminance level is reduced to a level lower than the peak luminance when the specified object is not included in the display image, and is increased to a level higher than the peak luminance when the specified object is included in the display image and information about the light source is not included in the display image.

Images