JP6466488B2 - Display device, television receiver, video processing method, control program, and recording medium - Google Patents

Description

  The present invention relates to a video processing apparatus that switches a conversion function between a gradation value and a luminance value.

  In recent years, as one of high image quality technologies, HDR (High Dynamic Range) which has more gradations (number of possible gradation values) and includes higher luminance information than SDR (Standard Dynamic Range) signals. ) The signal is getting attention. In addition, UHD BD discs capable of storing HDR signals have been commercialized. By using the HDR technology, it is possible to obtain a powerful image with higher brightness and higher contrast than before. The HDR signal includes luminance information of a maximum of about 10,000 nits as a standard. When the video indicated by the HDR signal includes a caption, the caption is also displayed with high luminance.

  As a technique for processing subtitles included in video, Patent Document 1 discloses that an original image is divided into video from which subtitles are extracted and information of subtitles that are extracted, and the divided information is interpolated and expanded. A circuit for synthesizing after performing reduction processing is disclosed.

JP 2001-169199 A (released on June 22, 2001)

  In the HDR technology, there is a demand for a technology for displaying a video with a more appropriate luminance according to the video signal.

  The present invention has been made in view of the above-described problems, and an object thereof is to display an image with a more appropriate luminance corresponding to a video signal in a technology for adjusting the luminance.

  In order to solve the above problem, a display device according to one embodiment of the present invention includes a plurality of conversion units that set luminance values from gradation values indicated by a video signal of a display target image, and the luminance of the video signal. A switching unit that switches the conversion means according to a level, and the switching unit refers to a luminance level of a corrected image obtained by excluding a region including an artificial display object from the display target image. Switch the conversion means.

  In order to solve the above-described problem, a video processing method according to an aspect of the present invention is a video processing method by a display device having a plurality of conversion units for setting a luminance value from a gradation value indicated by a video signal of a display target image. A switching step of switching the conversion means in accordance with a luminance level of the video signal, wherein the switching step is a correction obtained by excluding a region including an artificial display object from the display target image. The conversion means is switched with reference to the luminance level of the image.

  According to one embodiment of the present invention, in a technique for adjusting luminance, an image can be displayed with more appropriate luminance corresponding to a video signal.

It is a block diagram which shows the structure of the display apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the external appearance of the television receiver provided with the display apparatus which concerns on Embodiment 1 of this invention. It is a flowchart explaining the video processing method which concerns on Embodiment 1 of this invention. (A) is a front view which shows the external appearance of the display apparatus which is displaying the display target image containing a caption. (B) is a graph which shows the PQ curve of the display target image which the display apparatus shown to (a) of FIG. 4 displays. It is a block diagram which shows the structure of the display apparatus which concerns on Embodiment 2 of this invention. It is a flowchart explaining the video processing method which concerns on Embodiment 2 of this invention. It is a flowchart explaining the video processing method which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail. However, unless otherwise specified, the configuration described in the present embodiment is merely an illustrative example, and is not intended to limit the scope of the present invention. In the present specification, “switching tone mapping” means switching a method for converting a gradation value indicated by a video signal into a luminance value used when displaying a video.

Embodiment 1
(Display device 1)
A display device 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a block diagram illustrating a configuration of a display device 1 according to the present embodiment. FIG. 2 is a front view showing an appearance of a television receiver including the display device 1. As shown in FIG. 1, the display device 1 includes a video processing unit 2, a backlight 7, and a display unit 8. The video processing unit 2 is a member that performs conversion (tone mapping) between a gradation value and a luminance value indicated by the video signal using a conversion function (conversion means in the claims), and includes a caption detection unit 3 and a switching unit 4. A conversion unit 5 and a backlight control unit 6 are provided.

  The caption detection unit 3 detects an artificial display object (caption in this embodiment) in the display target image indicated by the video signal acquired from the outside, and artificially detects the luminance data (gradation value) of the display target image. Luminance data of a corrected image obtained by excluding luminance data of a region including a display object is generated.

  The switching unit 4 switches the conversion function used in the conversion unit 5 according to the luminance level of the corrected image generated by the caption detection unit 3.

  The conversion unit 5 converts the gradation value of the corrected image into a luminance value using the conversion function switched by the switching unit 4 (specifically, used when displaying video from the gradation value indicated by the video signal). Conversion to luminance value (tone mapping)).

  The backlight control unit 6 controls the luminance of each area of the backlight 7 corresponding to the corrected image displayed on the display unit 8 to the luminance value converted by the conversion unit 5. In addition, the backlight control unit 6 sets the luminance of each area of the backlight 7 corresponding to the region including the artificial display object displayed by the display unit 8 (the region detected by the caption detection unit 3) of other areas. The brightness value is controlled to be different from the brightness (local dimming).

  The backlight 7 is composed of a plurality of areas, the brightness of the plurality of areas can be individually controlled, and the display unit 8 is irradiated with light based on control by the backlight control unit 6.

  The display unit 8 is a non-luminous display, and displays a display target image indicated by a video signal (RGB data excluding luminance data). A liquid crystal display etc. are mentioned as an example of a non-light-emitting display.

  In the present embodiment, a configuration using the non-light emitting display unit 8 and the backlight 7 is shown. However, each area of the backlight 7 corresponding to the region including the artificial display object displayed on the display unit 8 is displayed. When the configuration (local dimming) for controlling the brightness to be different from the brightness of other areas is not adopted, only the self-luminous display is used as the display unit 8 without using the backlight 7. May be. Examples of the self-luminous display include an organic EL display, a plasma display, and an LED display.

(Video processing method)
A flow of a video processing method executed by the display device 1 according to the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing the flow of the backlight control method of the display device 1. Hereinafter, for simplification, description of the control of the display unit 8 is omitted.

  First, the caption detection unit 3 detects captions in a display target image indicated by an externally acquired video signal, and brightness data of an area including an artificial display object from brightness data (gradation value) of the display target image. The brightness data of the corrected image obtained by excluding is generated (step S0).

  Note that the caption detection unit 3 performs image processing such as edge detection using a filter on a display target image indicated by a video signal acquired from the outside, and excludes luminance data of a region including an artificial display object. be able to. However, the specific process of excluding the luminance data of the area including the artificial display object is not limited to the present embodiment.

  An example of the video signal processed by the caption detection unit 3 is an HDR signal. The HDR signal may be an HDMI signal based on HDMI (registered trademark) (High-Definition Multimedia Interface) standard, a Tuner signal (a signal received by a tuner), or the like.

  Further, the artificial display object detected by the caption detection unit 3 is a display object artificially created by CG (Computer Graphics) or the like, and is an object synthesized or added to the content video of the display target image. It can be. Examples of such objects include subtitles, logos (channel display), and control panels (OSDs that are superimposed on the transmission side such as STB and BD).

  As the next step after step S0, the switching unit 4 switches the conversion function used in the conversion unit 5 according to the luminance level of the luminance data of the corrected image generated by the caption detection unit 3 (step S1). As an example of the luminance level that the switching unit 4 refers to in order to switch the conversion function, the maximum gradation value or the average value of the gradation values in the luminance data of the corrected image can be cited.

  Next, the conversion unit 5 converts the gradation value of the corrected image into a luminance value using the conversion function switched by the switching unit 4 (step S2).

  Next, the backlight control unit 6 controls the luminance value of each area of the backlight 7 corresponding to the corrected image displayed on the display unit 8 to the luminance value converted by the conversion unit 5 (step S3).

  In step S3, the backlight control unit 6 determines the luminance of each area of the backlight 7 corresponding to the region including the artificial display object displayed by the display unit 8 (the region detected by the caption detection unit 3). The brightness value is controlled to be different from the brightness of other areas. Note that the backlight control unit adjusts the brightness (brightness) of the area corresponding to the region including the artificial display object displayed on the display unit 8 according to the gradation of the artificial display object. It is preferable that the brightness is different.

  In the present embodiment, the video processing unit 2 includes the conversion unit 5, and the conversion unit 5 converts the gradation value of the corrected image into a luminance value using the conversion function switched by the switching unit 4. Explained. However, one embodiment of the present invention is not limited to this. In one aspect of the present invention, the video processing unit 2 only needs to have a plurality of conversion means for setting the luminance value from the gradation value of the corrected image instead of using the conversion function (in the present embodiment, a plurality of conversion units are used). The switching unit 4 has only to switch the conversion unit according to the luminance level of the corrected image. For example, the video processing unit 2 has a table indicating correspondence between gradation values and luminance values in order to set luminance values from the gradation values of the corrected image, and the switching unit 4 displays the luminance level of the corrected image. The table to be referenced may be switched depending on

(Concrete example)
A specific example of the video processing method according to the present embodiment will be described below with reference to FIG. FIG. 4A is a front view showing an appearance of the display device 1 displaying a display target image including subtitles. FIG. 4B is a graph showing a PQ curve of the display target image displayed by the display device 1 shown in FIG. In FIG. 4B, the horizontal axis represents the gradation value before conversion, and the vertical axis represents the luminance value after conversion (luminance when displaying an image).

  As shown in FIG. 4A, the display unit 8 displays the corrected image A and the subtitle B obtained by excluding the luminance data of the area including the subtitle. In step S0 described above, the caption detection unit 3 detects the caption B in the display target image indicated by the video signal acquired from the outside, and the region including the caption B from the luminance data (gradation value) of the display target image. The brightness data of the corrected image A obtained by excluding the brightness data is generated.

  Next, in step S1, the switching unit 4 uses a PQ curve (EOTF according to SMPTE-ST2084) in which the graph of the gradation value before conversion and the luminance value after conversion corresponds to the maximum luminance level of the corrected image A. Switch to a conversion function that converts to the curve shown by. More specifically, the switching unit 4 converts the gradation value into a luminance value so that the luminance value corresponding to the maximum gradation value indicated by the video signal becomes a value of a predetermined maximum luminance level C. Switch to conversion function. Here, the predetermined maximum luminance level C may be an arbitrary value set in advance, but is set according to the luminance range that the video signal can take and the luminance range of the light that the backlight 7 can irradiate. Is preferred. An example of a specific value of the predetermined maximum luminance level C is 1000 nit.

  Next, in step S2, the conversion unit 5 converts the gradation value of the corrected image A into a luminance value using the conversion function switched by the switching unit 4. Next, in step S <b> 3, the backlight control unit 6 controls the luminance of each area of the backlight 7 corresponding to the corrected image A displayed on the display unit 8 to the luminance value converted by the conversion unit 5. Further, the backlight control unit 6 controls the luminance value of each area of the backlight 7 corresponding to the caption B displayed on the display unit 8 to a luminance value different from the luminance of the corrected image A.

  In the above specific example, for example, the gradation value corresponding to the caption B is larger than the gradation value corresponding to the corrected image A, and the switching unit 4 sets the maximum gradation value in the caption B in step S1 described above. When the conversion function is switched with reference, the PQ curve formed by the gradation value before conversion and the luminance value after conversion becomes like the dotted line in FIG. 4B, and the image becomes dark. .

  Therefore, in the present embodiment, in step S1, the switching unit 4 switches the conversion function with reference to the maximum gradation value of the corrected image A excluding the caption B from the display target image. As a result, the PQ curve formed by the gradation value before conversion and the luminance value after conversion becomes as shown by the solid line in FIG. 4B, and an image can be displayed with more appropriate luminance according to the video signal. it can.

  However, when only the luminance in the corrected image A is adjusted in this way, the luminance of the caption B may be relatively high. Therefore, the backlight control unit 6 controls the luminance of each area of the backlight 7 corresponding to the caption B displayed on the display unit 8 to be lower than the luminance of the corrected image A.

  The video processing method according to the present embodiment is also effective when the gradation value corresponding to the caption B is smaller than the gradation value corresponding to the corrected image A. In that case, the brightness of the corrected image A displayed by the display unit 8 is compared with the case where the subtitle B is not removed by switching the conversion function with reference to the maximum gradation value of the corrected image A excluding the subtitle B. As a result, the image becomes dark, and the image can be displayed with a more appropriate luminance according to the image signal. Further, the backlight control unit 6 may control the luminance of each area of the backlight 7 corresponding to the caption B displayed on the display unit 8 to be higher than the luminance of the corrected image A.

  In this specific example, an example of an absolute luminance method (including a PQ method) is shown as a luminance method when converting from a gradation value to a luminance value, but a relative luminance method (an HLG method or the like) is used as the luminance method. May be adopted. Even in that case, it is possible to achieve the same effect as the display device 1 according to the present embodiment.

(Summary of Embodiment 1)
When the display device displays the caption of the video indicated by the HDR signal, the conversion function applied to the luminance data of the image indicated by the HDR signal is switched with reference to the peak luminance and the average luminance in the luminance data included in the HDR signal. In that case, there is a problem that the conversion function is switched with reference to the peak luminance and the average luminance including the luminance data of the caption that may greatly change the peak luminance or the average luminance (APL).

  When a user displays subtitles with a controller or the like, in the case of an image with originally low peak luminance and low average luminance, the PQ curve is set to MAX CLL (for example, 10,000 nits) as the maximum luminance value. By changing the PQ curve to a PQ curve suitable for a display device, the optimum image quality can be supplied. However, due to the above problem, when a white character of a subtitle (current UHD-BD is set to 128/255, which is half of normal data) is displayed, this subtitle portion is detected as a peak luminance and PQ Create a curve. Further, even when a PQ curve is created with reference to the average luminance, the luminance of the subtitle portion is added, and the average luminance data cannot be obtained accurately. For this reason, it is not possible to display an image with the optimum brightness desired by the user.

  Therefore, the display device 1 according to the present embodiment switches the conversion unit with reference to the luminance level of the corrected image obtained by excluding the region including the artificial display object from the display target image. Accordingly, the luminance value can be set from the gradation value by the conversion unit according to the luminance level of the corrected image excluding an artificial display object that may greatly change the maximum luminance level or the average luminance level. . As a result, when the tone mapping method is switched with reference to the maximum luminance level or the average luminance level, the influence of the luminance of the artificial display object on the maximum luminance level or the average luminance level can be suppressed. Therefore, it is possible to display an image with a more appropriate luminance according to the image signal.

[Embodiment 2]
Embodiment 2 of the present invention will be described below with reference to FIGS. 5 and 6. For convenience of explanation, members having the same functions as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

(Display device 10)
The display device 10 according to the present embodiment will be described with reference to FIG. FIG. 5 is a block diagram illustrating a configuration of the display device 10 according to the present embodiment. As illustrated in FIG. 5, the display device 10 further includes a reception unit 12 of the video processing unit 11 in addition to the configuration of the display device 1 according to the first embodiment.

  The accepting unit 12 accepts selection by the user as to whether or not to execute the function of switching the conversion means with reference to the brightness level of the corrected image. In addition, the reception unit 12 determines whether or not to execute a function of making the brightness of the area (corresponding area) corresponding to the area including the artificial display object in the display target image different from the brightness of the other areas. Accepts selection by.

(Video processing method by display device 10)
A flow of a video processing method executed by the display device 10 according to the present embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing the flow of the video processing method executed by the display device 10. Note that description of steps similar to those described in Embodiment 1 is omitted.

  First, the accepting unit 12 accepts a selection by the user as to whether or not to execute a function of switching conversion means with reference to the brightness level of the corrected image (step S10). In step S10, the reception unit 12 performs a function of making the brightness of an area (corresponding area) corresponding to an area including an artificial display object in the display target image different from the brightness of other areas. The selection by the user is accepted.

  Hereinafter, an example of step S10 will be described. For example, when the artificial display object is a caption, a logo, or a control panel, the user sets whether or not to display these in the user menu, and the reception unit 12 receives the setting. And when the reception part 12 receives the setting which displays a subtitle, a logo, or a control panel, it progresses to the next process. In addition, when the reception unit 12 receives a setting for displaying a caption, a logo, or a control panel, the backlight control unit 6 displays an area (corresponding area) corresponding to an area including an artificial display object in the display target image. The backlight control unit 6 is instructed to execute a function of making the brightness different from the brightness of other areas.

  As the next step of step S10, the caption detection unit 3 detects the caption in the display target image indicated by the video signal acquired from the outside based on the user's selection received by the reception unit 12, and the luminance of the display target image. From the data (gradation value), the luminance data of the corrected image obtained by excluding the luminance data of the area including the artificial display object is generated (step S11).

  Next, the switching unit 4 switches the conversion function used in the conversion unit 5 according to the luminance level of the luminance data of the corrected image generated by the caption detection unit 3 (step S12).

  Next, the conversion unit 5 converts the gradation value of the corrected image into a luminance value using the conversion function switched by the switching unit 4 (step S13).

  Next, the backlight control unit 6 controls the luminance of each area of the backlight 7 corresponding to the corrected image displayed on the display unit 8 to the luminance value converted by the conversion unit 5 (step S14).

  In step S <b> 14, the backlight control unit 6 includes an artificial display object displayed on the display unit 8 based on the user selection received by the reception unit 12 (region detected by the caption detection unit 3). The brightness of each area of the backlight 7 corresponding to is controlled to a brightness value different from the brightness of other areas.

(Summary of Embodiment 2)
As described above, the display device 10 according to the present embodiment accepts the selection by the user as to whether or not to execute the function of switching the conversion means with reference to the luminance level of the corrected image. Thereby, the user can select whether to switch the conversion means with reference to the luminance level of the corrected image.

  Further, the display device 10 according to the present embodiment determines whether or not to execute the function of making the brightness of the corresponding area corresponding to the area including the artificial display object in the display target image different from the brightness of the other areas. , Accepts selection by the user. This adjusts the brightness of the backlight corresponding to each area so that there is no unnatural boundary between the area containing the artificial display object and the area other than the area containing the artificial display object. Can do. Therefore, it is possible to display an image with a more appropriate luminance according to the image signal.

[Embodiment 3]
Embodiment 3 of the present invention will be described below with reference to FIG. Note that the video processing method according to the present embodiment can be executed by using the display device 1 according to the first embodiment. Therefore, for convenience of explanation, members having the same functions as those described in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

(Video processing method according to Embodiment 3)
A flow of a video processing method executed by the display device 1 according to the present embodiment will be described with reference to FIG. FIG. 7 is a flowchart showing the flow of the video processing method executed by the display device 1. Note that description of steps similar to those described in Embodiment 1 is omitted.

  First, the caption detection unit 3 determines the category, genre, or scene type of the display target image indicated by the video signal from the metadata included in the video signal acquired from the outside, and converts it with reference to the luminance level of the corrected image. It is determined whether or not to execute a function for switching means (step S20). When the caption detection unit 3 determines to execute the function of switching the conversion means with reference to the luminance level of the corrected image, the process proceeds to step S21. When the caption detection unit 3 determines not to execute the function of switching the conversion unit with reference to the luminance level of the corrected image, the process ends.

  As an example of a method for determining whether or not to execute the function of switching the conversion means with reference to the luminance level of the corrected image, the caption detection unit 3 uses a display object whose category, genre, or scene is an artificial display object. In the case of a category, genre, or scene that has a high possibility of being included, there is a method of determining to execute a function of switching conversion means with reference to the luminance level of the corrected image. In that case, when the category of the display target image is a movie, the display target image is likely to include subtitles, so the subtitle detection unit 3 executes a function of switching the conversion means with reference to the luminance level of the corrected image. Judge that. When the category of the display target image is sports, the caption detection unit 3 further determines whether the scene of the display target image is indoor or outdoor, and based on the determination, the switching unit 4 The conversion function may be switched (for example, in conjunction with the average luminance of the display target image).

  In step S20, the caption detection unit 3 determines the category, genre, or scene type of the display target image indicated by the video signal from the metadata included in the video signal acquired from the outside, and artificially displays the image in the display target image. It is determined whether or not to execute a function of making the brightness of the corresponding area corresponding to the area including the display object different from the brightness of the other areas. The determination method is the same as the method for determining whether to execute the function of switching the conversion means with reference to the luminance level of the corrected image. For this reason, the caption detection unit 3 performs a function of switching the conversion means with reference to the brightness level of the corrected image to determine whether to execute the function of making the brightness of the corresponding area different from the brightness of the other areas. It may be determined depending on whether or not to do so.

  In step S21, the caption detection unit 3 detects the caption in the display target image indicated by the video signal acquired from the outside, and includes an artificial display object from the luminance data (gradation value) of the display target image. The brightness data of the corrected image obtained by excluding the brightness data of the area is generated (step S21).

  Next, the switching unit 4 switches the conversion function used in the conversion unit 5 in accordance with the luminance level of the luminance data of the corrected image generated by the caption detection unit 3 (step S22).

  Next, the conversion unit 5 converts the gradation value of the corrected image into a luminance value using the conversion function switched by the switching unit 4 (step S23).

  Next, the backlight control unit 6 controls the luminance of each area of the backlight 7 corresponding to the corrected image displayed on the display unit 8 to the luminance value converted by the conversion unit 5 (step S24).

  If it is determined in step S20 that the caption detection unit 3 performs the function of making the brightness of the corresponding area different from the brightness of the other areas, the backlight control unit 6 displays the display unit 8 in step S24. The luminance of each area of the backlight 7 corresponding to the area including the artificial display object (area detected by the caption detection unit 3) displayed by is controlled to a luminance value different from the luminance of the other areas.

(Summary of Embodiment 3)
As described above, the display device 1 according to the present embodiment switches the conversion unit with reference to the luminance level of the corrected image according to the category, genre, or scene of the display target image. As a result, when there is a high possibility that the category, genre, or scene of the display target image includes an artificial display object, the conversion means is switched with reference to the luminance level of the corrected image as necessary. The conversion means can be switched.

  Further, the display device 1 according to the present embodiment makes the brightness of the corresponding area different from the brightness of other areas according to the category, genre, or scene of the display target image. As a result, when there is a high possibility that the category, genre, or scene of the display target image contains an artificial display object, the brightness of the corresponding area is made different from the brightness of other areas as necessary. Local dimming can be performed.

[Example of software implementation]
The control blocks of the display devices 1 and 10 (in particular, the caption detection unit 3, the switching unit 4, the conversion unit 5, the backlight control unit 6, and the reception unit 12) are logic circuits formed in an integrated circuit (IC chip) or the like. (Hardware) or software using a CPU (Central Processing Unit).

  In the latter case, the display devices 1 and 10 include a CPU that executes instructions of a program that is software that realizes each function, and a ROM (Read Only Memory) in which the program and various data are recorded so as to be readable by a computer (or CPU). ) Or a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) for expanding the program, and the like. The computer (or CPU) reads the program from the recording medium and executes the program, thereby achieving the object of one embodiment of the present invention. As the recording medium, a “non-temporary tangible medium” such as a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. The program may be supplied to the computer via an arbitrary transmission medium (such as a communication network or a broadcast wave) that can transmit the program. Note that one embodiment of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

[Summary]
The display devices (1, 10) according to the first aspect of the present invention have a plurality of conversion means for setting a luminance value from the gradation value indicated by the video signal of the display target image, according to the luminance level of the video signal. A switching unit (4) for switching the conversion means, and the switching unit refers to the luminance level of a corrected image obtained by excluding a region including an artificial display object from the display target image. Switch means.

  According to the above configuration, the luminance value is set from the gradation value by the conversion unit according to the luminance level of the corrected image excluding an artificial display object that may greatly change the maximum luminance level or the average luminance level. can do. As a result, when the tone mapping method is switched with reference to the maximum luminance level or the average luminance level, the influence of the luminance of the artificial display object on the maximum luminance level or the average luminance level can be suppressed. Therefore, it is possible to display an image with a more appropriate luminance according to the image signal.

  A display device (1, 10) according to aspect 2 of the present invention is the above-described aspect 1, wherein the display device (1, 10) is composed of a plurality of areas, and the backlight (7) capable of individually controlling the brightness of the plurality of areas and the backlight. A backlight control unit (6) for controlling the light, wherein the backlight control unit makes the brightness of the area corresponding to the area including the artificial display object different from the brightness of the other areas. May be.

  According to the above configuration, the brightness of the backlight corresponding to each region so that there is no unnatural boundary between the region including the artificial display object and the region other than the region including the artificial display object. Can be adjusted.

  In the display device (1, 10) according to aspect 3 of the present invention, in the aspect 2, the backlight control unit determines the brightness of the area corresponding to the area including the artificial display object. Depending on the gradation of the display object, the brightness of other areas may be different.

  According to the above configuration, in the display device according to aspect 2, each region is set so that there is no unnatural boundary between the region including the artificial display object and the region other than the region including the artificial display object. The backlight brightness corresponding to can be adjusted more appropriately.

  In the display device (1, 10) according to aspect 4 of the present invention, in the above aspects 1 to 3, the artificial display object may be an object synthesized or added to the content video of the display target image. .

  According to the above configuration, according to the above configuration, when the tone mapping method is switched with reference to the maximum luminance level or the average luminance level, the maximum luminance level based on the luminance of the object synthesized or added to the content video. Alternatively, the influence on the average luminance level can be suppressed.

  In the display device (1, 10) according to aspect 5 of the present invention, in the aspect 4, the object may be a caption, a logo, or a control panel.

  According to the above configuration, when the tone mapping method is switched with reference to the maximum luminance level or the average luminance level, the influence on the maximum luminance level or the average luminance level due to the luminance of the caption, logo, or control panel is suppressed. be able to.

  In the display device (1, 10) according to aspect 6 of the present invention, in the above aspects 1 to 5, the conversion means is a conversion function between a gradation value and a luminance value by a conversion function, and the switching unit is The conversion function may be switched to a conversion function that converts the graph of the gradation value before conversion and the luminance value after conversion into a PQ curve corresponding to the maximum luminance level of the corrected image.

  According to said structure, an image | video can be displayed with the more suitable brightness | luminance according to the HDR signal.

  The display device (10) according to aspect 7 of the present invention provides a display device (10) according to any one of aspects 1 to 6, wherein the switching unit performs a function of switching the conversion unit with reference to a luminance level of the corrected image. You may further provide the reception part which receives selection.

  According to the above configuration, the user can select whether to switch the conversion means with reference to the luminance level of the corrected image.

  In the display device (1, 10) according to aspect 8 of the present invention, in the above aspects 1 to 7, the switching unit refers to the luminance level of the corrected image according to the category, genre, or scene of the display target image. Then, the conversion means may be switched.

  According to the above configuration, when there is a high possibility that the category, genre, or scene of the display target image includes an artificial display object, the conversion unit is switched by referring to the luminance level of the corrected image. The switching of the conversion means can be executed as necessary.

  The television receiver (100) which concerns on aspect 9 of this invention is provided with the display apparatus in any one of the said aspects 1-8.

  According to said structure, the effect which the said display apparatus has in each said aspect can be acquired in the said television receiver.

  A video processing method according to aspect 10 of the present invention is a video processing method by a display device (1, 10) having a plurality of conversion means for setting a luminance value from a gradation value indicated by a video signal of a display target image, A switching step of switching the conversion means according to the luminance level of the video signal, wherein the switching step includes a luminance level of a corrected image obtained by excluding a region including an artificial display object from the display target image. The conversion means is switched with reference to FIG.

  According to said structure, there exists an effect similar to the said aspect 1. FIG.

  The video processing apparatus according to each aspect of the present invention may be realized by a computer. In this case, the video processing apparatus is operated on each computer by causing the computer to operate as each unit (software element) included in the video processing apparatus. Also included in the scope of the present invention are a control program for the video processing apparatus to be realized and a computer-readable recording medium on which the program is recorded.

  The embodiment of the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and technical means disclosed in different embodiments are appropriately combined. The obtained embodiment is also included in the technical scope of the embodiment of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

DESCRIPTION OF SYMBOLS 1,10 Display apparatus 2,11 Video processing part 3 Subtitle detection part 4 Switching part 5 Conversion part 6 Backlight control part 7 Backlight 8 Display part 12 Reception part

Claims (10)

Having a plurality of conversion functions for converting the gradation value indicated by the video signal of the display target image into a luminance value used when displaying the video;
A switching unit for switching the conversion function,
The switching unit refers to the maximum gradation value in the gradation value of the corrected image obtained by excluding the region including the artificial display object from the display target image, and converts the conversion function before conversion. Switch to a conversion function that converts the graph of the gradation value and the luminance value after conversion to form a PQ curve corresponding to the maximum gradation value of the corrected image ,
The display device, wherein the switching unit controls whether or not to execute a function of switching the conversion function according to a category, a genre, or a scene of the display target image . A backlight composed of a plurality of areas and capable of individually controlling the brightness of the plurality of areas,
A backlight control unit for controlling the backlight;
The display device according to claim 1, wherein the backlight control unit makes the brightness of an area corresponding to the area including the artificial display object different from the brightness of another area. The backlight control unit makes the brightness of an area corresponding to the area including the artificial display object different from the brightness of other areas according to the gradation of the artificial display object. The display device according to claim 2. The display device according to claim 1, wherein the artificial display object is an object synthesized or added to a content video of the display target image. The display device according to claim 4, wherein the object is a caption, a logo, or a control panel. The switching unit further includes a receiving unit that receives a selection by a user as to whether or not to execute the function of switching the conversion function with reference to the maximum gradation value in the gradation value of the corrected image. The display device according to any one of claims 1 to 5. Television receiver and a display device according to any one of claims 1-6. A video processing method by a display device having a plurality of conversion functions for converting a gradation value indicated by a video signal of a display target image into a luminance value used when displaying a video,
Including a switching step of switching the conversion function,
In the switching step, with reference to the maximum gradation value in the gradation value of the corrected image obtained by excluding the region including the artificial display object from the display target image, the conversion function is Switch to a conversion function that converts the graph of the gradation value and the luminance value after conversion to form a PQ curve corresponding to the maximum gradation value of the corrected image ,
The video processing method characterized in that, in the switching step, whether or not to execute a function of switching the conversion function is controlled according to a category, a genre, or a scene of the display target image .   A control program for causing a computer to function as the display device according to claim 1, wherein the control program causes the computer to function as the switching unit. A computer-readable recording medium on which the control program according to claim 9 is recorded.

Images