JP2010210722A - Display, program and information storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display, capable of appropriately preventing the generation of planarization of luminance, which is unintended. <P>SOLUTION: A projector 100 includes a feature information creating section 120 for creating a first feature information, based on an image signal before progressive conversion; a feature information creating section 140 for creating a second feature information based on an image signal after the progressive conversion; and a luminance expanding section 150 for expanding the luminance, wherein the luminance expanding section 150 includes: a tentative expansion coefficient creating section 152 for creating a second tentative expansion coefficient, based on the second feature information; an expansion coefficient determining section 154 for determining the adjusted expansion coefficient or the adjusted expansion coefficient, based on the second tentative expansion coefficient as an adaptive expansion coefficient; and an expansion processing section 156 for performing expansion processing on the image signal, after the progressive conversion. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a display device, a program, and an information storage medium.

  The display device can improve the contrast of the displayed image by performing dimming and luminance expansion according to the luminance of the input image. However, by performing dimming and luminance expansion, a so-called overexposure (brightness flattening in a high gradation portion) may occur in a displayed image. As a technique for solving such a problem, Japanese Patent Laid-Open No. 2005-257761 discloses an image parameter extracting unit that extracts an image parameter characterizing the brightness of a display image from an image signal every unit time, and based on the image parameter. A dimming control parameter for determining a dimming control parameter and performing a dimming process based on the dimming control parameter, and a decompression process based on the image parameter extracted by the image parameter extracting unit A decompression processing unit that determines a decompression control parameter and performs a decompression process based on the decompression control parameter. The decompression processing unit determines that the maximum gradation of the input image signal is greater than the maximum gradation that can be output after the decompression process. A display device is described in which expansion control parameters are determined so as to achieve a low gradation, and expansion processing is performed.

Japanese Patent Laid-Open No. 2005-257761

  However, in order to determine the dimming control parameter based on the image parameter, the entire image must be searched, and the dimming control parameter can be used for the next image (frame). For this reason, when a continuous image changes greatly, there is a possibility that inappropriate light control is performed. In addition, a method of newly providing a frame memory to prevent processing delay is conceivable. However, in this method, the real-time property of the image processing is impaired and the manufacturing cost increases.

  In general, a display device includes an IP conversion unit that converts an interlace signal into a progressive signal when the input image signal is an interlace signal. The IP conversion unit has a frame memory capable of storing image signals for a plurality of frames in order to determine the type of image signal. In this case, a method of estimating the image signal after being output from the IP conversion unit by measuring the image signal before being input to the IP conversion unit is conceivable. However, since there are various types of image signals, and the number of frames used in progressive conversion varies depending on the type, the image signal before the display device is input to the IP conversion unit is measured and output from the IP conversion unit. It is difficult to prevent overexposure by estimating the image signal.

  An object of the present invention is to provide a display device, a program, and an information storage medium that can more appropriately prevent the occurrence of unintended luminance flattening when performing luminance expansion.

  In order to solve the above-described problem, a projector according to the present invention includes a first feature information generation unit that generates first feature information related to image brightness based on an image signal before progressive conversion, and an image after progressive conversion. A second feature information generation unit configured to generate second feature information related to the brightness of the image based on the signal; and a luminance expansion unit configured to perform luminance expansion, wherein the luminance expansion unit includes the second feature information. A temporary expansion coefficient generation unit that generates a second temporary expansion coefficient based on at least a part of the first brightness value included in the first feature information, and a second brightness value included in the second feature information. An expansion coefficient determination unit that determines, as an applied expansion coefficient, the second temporary expansion coefficient or an adjustment expansion coefficient based on the second temporary expansion coefficient according to a difference from the brightness value of The prog Characterized in that it comprises a decompression unit for performing expansion processing to the image signal after Sibu conversion, the.

  In addition, the program according to the present invention includes a first feature information generation unit that generates first feature information related to image brightness based on an image signal before progressive conversion, and an image signal after progressive conversion. Based on the second feature information generation unit that generates second feature information related to the brightness of the image, and a luminance expansion unit that performs luminance expansion, and the luminance expansion unit includes at least one of the second feature information. A temporary expansion coefficient generation unit that generates a second temporary expansion coefficient based on the first part, a first brightness value included in the first feature information, and a second brightness included in the second feature information An expansion coefficient determining unit that determines, as an applied expansion coefficient, the second temporary expansion coefficient or an adjustment expansion coefficient based on the second temporary expansion coefficient according to a difference from the value, and the program based on the applied expansion coefficient Characterized in that it comprises a decompression unit for performing expansion processing to the image signal after Sibu conversion, the.

  An information storage medium according to the present invention is an information storage medium that stores a computer-readable program, and stores the program.

  According to the present invention, the display device or the like can more appropriately prevent the occurrence of unintended luminance flattening without impairing the real-time property of the image processing by using the feature information before and after the progressive conversion. .

  The expansion coefficient determination unit determines whether the first brightness value is larger than the second brightness value, the first brightness value, and the second brightness. A difference value calculation unit that calculates a difference value with respect to a value, an expansion coefficient correction value generation unit that generates an expansion coefficient correction value greater than 0 and less than or equal to 1 based on the difference value and expansion coefficient correction value data; An adjustment expansion coefficient generation unit that generates the adjustment expansion coefficient by multiplying a second temporary expansion coefficient and the expansion coefficient correction value, and the first brightness value is greater than the second brightness value. The adjusted expansion coefficient is determined as the applied expansion coefficient, and when the first brightness value is not greater than the second brightness value, the second temporary expansion coefficient is determined as the applied expansion coefficient. And an applicable expansion coefficient determination unit that determines as follows.

  According to this, the display device or the like can grasp the temporal change in the brightness of the image by comparing the brightness values before and after the progressive conversion, and perform the luminance expansion according to the change. Can do.

  The temporary expansion coefficient generation unit generates a first temporary expansion coefficient based on at least a part of the first feature information, and the expansion coefficient determination unit determines that the first brightness value is the second brightness value. A determination unit that determines whether the brightness value is greater than the brightness value, an average value calculation unit that calculates an average value of the first temporary expansion coefficient and the second temporary expansion coefficient, and the first brightness When the value is greater than the second brightness value, the average value is determined as the applied expansion coefficient, and when the first brightness value is not greater than the second brightness value, the second value is determined. And an applied expansion coefficient determination unit that determines the temporary expansion coefficient as the applied expansion coefficient.

  According to this, the display device or the like can grasp the temporal change in the brightness of the image by comparing the brightness values before and after the progressive conversion, and the change is abrupt. Also, by using the average value, excessive luminance expansion can be suppressed.

  In addition, the second feature information generation unit may generate at least information indicating a white peak value and information indicating APL as the second feature information.

  According to this, the display device or the like can perform appropriate expansion according to the brightness of the image by using the white peak value and the APL.

  The temporary expansion coefficient generation unit is based on expansion coefficient generation data in which the white peak value, the APL, the white peak value, the APL, and the second temporary expansion coefficient are associated with each other. The second temporary expansion coefficient may be generated.

  According to this, the display device or the like can perform appropriate expansion according to the brightness of the image by determining the temporary expansion coefficient from the white peak value and the APL.

  Further, the display device may include a light control unit that performs light control based on the second feature information or the applied expansion coefficient.

  According to this, the display device or the like can display an image with appropriate brightness by performing luminance expansion and dimming.

It is a functional block diagram of the projector in a 1st Example. It is a functional block diagram of the expansion coefficient determination unit in the first embodiment. It is a flowchart which shows the projection procedure of the image in a 1st Example. It is a flowchart which shows the expansion | extension processing procedure in 1st Example. It is a schematic diagram of the expansion coefficient generation data in the first embodiment. It is a schematic diagram when four points are defined in the expansion coefficient generation data in the first embodiment. It is a schematic diagram when three points are defined in the expansion coefficient generation data in the first embodiment. It is a schematic diagram of the expansion coefficient correction data in the first embodiment. It is a flowchart which shows the light control process sequence in a 1st Example. It is a functional block diagram of the projector in a 2nd Example. It is a functional block diagram of the expansion coefficient determination part in a 2nd Example.

  Embodiments in which the present invention is applied to a projector will be described below with reference to the drawings. In addition, the Example shown below does not limit the content of the invention described in the claim at all. In addition, all the configurations shown in the following embodiments are not necessarily essential as means for solving the invention described in the claims.

(First embodiment)
FIG. 1 is a functional block diagram of a projector 100 according to the first embodiment. The projector 100 includes an image signal input unit 110 for inputting an image signal (for example, a moving image signal such as an RGB signal) and a brightness level of an image represented by the image signal based on the image signal before progressive conversion. A feature information generation unit (first feature information generation unit) 120 that generates one feature information, an IP conversion unit 130 that performs progressive conversion (IP conversion), and an image signal based on the image signal after progressive conversion. A feature information generation unit (second feature information generation unit) 140 that generates second feature information related to the brightness of the represented image is configured.

  The projector 100 includes a luminance expansion unit 150 that performs luminance expansion, a projection unit 190 that includes a light adjustment unit 192, and a light adjustment processing unit 160 that controls the light adjustment unit 192. The dimming processing unit 160 includes a dimming coefficient generation unit 162 that generates a dimming coefficient, and a dimming control unit 164 that controls the dimming unit 192 according to the dimming coefficient.

  In addition, the luminance expansion unit 150 includes a temporary expansion coefficient generation unit 152 that generates a second temporary expansion coefficient based on at least a part of the second feature information, and a first brightness value included in the first feature information. And a second temporary expansion coefficient or an expansion coefficient that determines an adjustment expansion coefficient based on the second temporary expansion coefficient as an applied expansion coefficient in accordance with a difference from the second brightness value included in the second feature information The determination unit 154 includes an expansion processing unit 156 that executes an expansion process on the image signal after progressive conversion based on the applied expansion coefficient.

  Here, the expansion coefficient determination unit 154 will be described in more detail. FIG. 2 is a functional block diagram of the expansion coefficient determination unit 154 in the first embodiment. The expansion coefficient determination unit 154 determines whether the first brightness value is greater than the second brightness value, and the difference value between the first brightness value and the second brightness value. A difference value calculation unit 182 that calculates the expansion coefficient correction value generation unit 183 that generates an expansion coefficient correction value greater than 0 and less than or equal to 1 based on the difference value and the expansion coefficient correction value data, and a second temporary expansion An adjustment expansion coefficient generating unit 184 that generates an adjustment expansion coefficient by multiplying the coefficient by the expansion coefficient correction value, and applying the adjustment expansion coefficient when the first brightness value is larger than the second brightness value. And an applied expansion coefficient determining unit 188 that determines the expansion coefficient and determines the second temporary expansion coefficient as the applied expansion coefficient when the first brightness value is not larger than the second brightness value. Yes.

  Note that the projector 100 may implement the functions of these units using the following hardware. For example, the projector 100 includes an image signal input unit 110, an image input terminal, a converter, and the like, a feature information generation unit 120, 140, an image processing circuit, the IP conversion unit 130, an image processing circuit, a RAM, a luminance expansion unit 150, The dimming processing unit 160 is a CPU, RAM, image processing circuit, etc., the projection unit 190 is a lamp, a liquid crystal panel, a liquid crystal driving circuit, a lens, etc., and the dimming unit 192 is a lamp power source unit (function to adjust the brightness of the lamp by power control). ), A light shielding plate (having a function of blocking output light), a liquid crystal light valve (having a function of blocking output light), or the like.

  Further, the projector 100 may read the program stored in the information storage medium 200 and execute the process of the feature information generation unit 120 and the like. As such an information storage medium 200, for example, a CD-ROM, DVD-ROM, ROM, RAM, HDD, or the like can be applied.

  Next, an image projection procedure using these units will be described. FIG. 3 is a flowchart showing an image projection procedure in the first embodiment. The feature information generation unit 120 generates first feature information based on the image signal from the image signal input unit 110 (step S1).

  The feature information includes, for example, a luminance histogram (data indicating the frequency for each gradation level from the lowest gradation to the highest gradation in the entire image or a predetermined area in the image), white peak value WP (entire image or in the image The luminance value of the pixel having the highest luminance value among the pixels in the predetermined area), APL (Average Picture Level), and the like. Further, the processing unit may be one pixel or a plurality of pixels. For example, the feature information generation unit 120 may process a 16 × 16 pixel block as one processing unit and an average luminance value of 16 × 16 pixels as a luminance value of the pixel block.

  The luminance value may be, for example, the maximum value among the R signal value, the G signal value, and the B signal value, or a value obtained by multiplying each signal value by a coefficient (for example, 0.299R + 0.587G). + 0.144B, 0.2126R + 0.7152G + 0.722B, etc.).

  The IP conversion unit 130 performs IP conversion (progressive conversion) on the image signal from the image signal input unit 110 (step S2). The feature information generation unit 140 generates second feature information based on the image signal after the progressive conversion (step S3).

  The second feature information is the same information as the first feature information. For example, when the second feature information is information indicating the feature of the image of the nth frame, the first feature information is information indicating the feature of the image delayed by at least one frame such as the n + 1th frame and the n + 2th frame. It is.

  After the generation of the second feature information, the projector 100 executes the extension process and the light control process (step S4). First, the decompression process procedure will be described.

  FIG. 4 is a flowchart showing a decompression processing procedure in the first embodiment. The temporary expansion coefficient generation unit 152 includes a second white peak value WP represented by the second characteristic information, a second APL represented by the second characteristic information, a white peak value and APL, and a temporary expansion coefficient. Is used to generate a temporary expansion coefficient Kgt using expansion coefficient generation data (for example, a two-dimensional look-up table) (step S11).

  FIG. 5 is a schematic diagram of expansion coefficient generation data in the first embodiment. FIG. 6 is a schematic diagram when four points are defined in the expansion coefficient generation data in the first embodiment. FIG. 7 is a schematic diagram when three points are defined in the expansion coefficient generation data in the first embodiment.

  In FIG. 5, the circled part is a part where a value is defined. The values of n1 to n7 are arbitrary integers from 1 to 1022, for example, n1 = 511, n2 = 551, n3 = 596, n4 = 649, n5 = 715, n6 = 793, and n7 = 894. In FIG. 3, the value is not defined at the lower right because the average value (APL) does not exceed the maximum value (white peak value).

  For example, when APL is 540 and white peak value is 550, it is a portion between four points defined. In this case, as shown in FIG. 6, the temporary expansion coefficient generator 152 sets the temporary expansion coefficient Kgt to (kg1 * S1 + kg2 * S2 + kg3 * S3 + kg4 * S4) / (S1 + S2 + S3 + S4). ) Is calculated. For example, when APL is 400 and white peak value is 500, it is a portion between three defined points. In this case, the temporary expansion coefficient generator 152 calculates the temporary expansion coefficient Kgt by calculating (kg1 * S1 + kg2 * S2 + kg3 * S3) / (S1 + S2 + S3) as shown in FIG. .

  As described above, the temporary expansion coefficient generation unit 152 can obtain the temporary expansion coefficient Kgt by performing the interpolation operation even if the value is not defined in the expansion coefficient generation data.

  The determination unit 181 in the expansion coefficient determination unit 154 has a second white peak in which the first white peak value (first brightness value) represented by the first feature information is represented by the second feature information. It is determined whether or not the value is greater than the value (second brightness value) (step S12). The fact that the first white peak value is larger than the second white peak value means that the image becomes bright and whiteout is likely to occur.

  When the first white peak value is larger than the second white peak value, the difference value calculation unit 182 calculates the difference value Dwp between the first white peak value and the second white peak value, and corrects the expansion coefficient. The value generation unit 183 generates the expansion coefficient correction value C based on the difference value Dwp and the expansion coefficient correction data in which the difference value and the expansion coefficient correction value are associated (step S13).

  FIG. 8 is a schematic diagram of expansion coefficient correction data in the first embodiment. As shown in FIG. 8, the expansion coefficient correction value C is a value greater than 0 and less than or equal to 1. For example, when the difference value Dwp is equal to or less than D1 (a value greater than 0), the expansion coefficient correction value C is 1. When the difference value Dwp is greater than D1 and less than D2, the expansion coefficient correction value C decreases. When the difference value Dwp is equal to or greater than D2, the expansion coefficient correction value C becomes the lower limit value C0.

  The adjustment expansion coefficient generation unit 184 generates Kgt * C as the adjustment expansion coefficient, and the application expansion coefficient determination unit 188 applies the Kgt * C as the application expansion coefficient Kg (step S14). That is, in this case, since C is a value greater than 0 and less than or equal to 1, Kg is a value less than or equal to Kgt.

  On the other hand, when the first white peak value is not larger than the second white peak value, that is, when the first white peak value is equal to or smaller than the second white peak value, the image becomes dark, and thus whiteout occurs. Hard to do. In this case, the applied expansion coefficient determination unit 188 applies the temporary expansion coefficient Kgt as it is as the applied expansion coefficient Kg (step S15).

  The expansion processing unit 156 performs expansion processing on the image signal after progressive conversion based on the applied expansion coefficient Kg (step S16). For example, the decompression processing unit 156 may perform decompression processing by calculating R ′ = (1 + Kg / 256) R, G ′ = (1 + Kg / 256) G, and B ′ = (1 + Kg / 256) B. Here, R ′, G ′, and B ′ are RGB image signal values after decompression, and R, G, and B are RGB image signal values before decompression.

  Next, the light control processing procedure will be described. FIG. 9 is a flowchart showing the light control processing procedure in the first embodiment.

  The dimming coefficient generation unit 162, based on the second white peak value, the second APL, and the dimming coefficient generation data, similarly to the luminance coefficient generation procedure in the luminance extension processing procedure described above. Kl is generated (step S21).

  The dimming control unit 164 calculates an aperture ratio A = Kl / 255 (step S22). And the light control part 164 controls the light control part 192 by the aperture ratio A (step S23). For example, it is brightest when the aperture ratio A is 1 (aperture ratio 100%), and darkest when the aperture ratio A is 0.

  After the expansion / dimming process (step S4) as described above, the luminance expansion unit 150 generates an image by outputting the image signal after luminance expansion to the projection unit 190, and the projection unit 190 performs luminance expansion and adjustment. An image is projected in a state where light is applied (step S5). The projector 100 determines whether or not the process should be terminated by turning off the power (step S6). If the process is not to be terminated, the processes of steps S1 to S6 described above are repeatedly executed.

  As described above, according to the present embodiment, the projector 100 uses the feature information before and after the progressive conversion, thereby causing unintentional brightness flattening such as overexposure without impairing the real-time property of the image processing. Can be prevented more appropriately.

  In addition, according to the present embodiment, the projector 100 can grasp the temporal change in the brightness of the image by comparing the brightness values before and after the progressive conversion, and the luminance expansion according to the change. It can be performed.

  Further, according to the present embodiment, the projector 100 can perform appropriate expansion according to the brightness of the image by using the white peak value and the APL, and determines the expansion coefficient from the white peak value and the APL. Thus, it is possible to perform appropriate expansion according to the brightness of the image.

  Further, according to the present embodiment, the projector 100 can display a high-contrast image with appropriate brightness by performing luminance expansion and dimming.

(Second embodiment)
In the first embodiment, when the white peak value in the feature information generation unit 120 is larger than the white peak value in the feature information generation unit 140, the temporary expansion coefficient is reduced using the expansion coefficient correction value data. In this case, Alternatively, the average value of the temporary expansion coefficient may be applied.

  FIG. 10 is a functional block diagram of the projector 101 in the second embodiment. In the projector 101, a temporary expansion coefficient generation unit 153 and an expansion coefficient determination unit 155 included in the luminance expansion unit 151 are different from the configuration of the first embodiment. Note that the projector 101 may function as the temporary expansion coefficient generation unit 153 or the like by executing a program read from the information storage medium 201 as in the first embodiment.

  The temporary expansion coefficient generation unit 153 not only generates the second temporary expansion coefficient according to the second feature information by the feature information generation unit 140 but also the first expansion according to the first feature information by the feature information generation unit 120. A temporary expansion coefficient of 1 is generated. Note that the method for generating the temporary expansion coefficient is the same as that in the first embodiment, and a description thereof will be omitted.

  FIG. 11 is a functional block diagram of the expansion coefficient determination unit 155 in the second embodiment. The expansion coefficient determination unit 155 includes the determination unit 181 described above, an average value calculation unit 185 that calculates an average value of the first temporary expansion coefficient and the second temporary expansion coefficient, and an applicable expansion coefficient determination unit 189. It is configured.

  When the white peak value in the feature information generation unit 120 is larger than the white peak value in the feature information generation unit 140, the application expansion coefficient determination unit 189 determines the average value calculated by the average value calculation unit 185 as the application expansion coefficient. Otherwise, the second temporary expansion coefficient is determined as the applicable expansion coefficient.

  As described above, according to the present embodiment, the projector 101 has the same effect as that of the first embodiment, and compares the brightness values before and after the progressive conversion, so that the temporal brightness of the image is improved. In addition, it is possible to grasp an excessive change, and even if the change is abrupt, excessive luminance expansion can be suppressed by using the average value.

(Other examples)
In addition, application of this invention is not limited to the Example mentioned above, A various deformation | transformation is possible. For example, in the embodiment described above, the determination unit 181 uses the white peak value, but the brightness may be compared using APL.

  In addition, the dimming processing unit 160 may execute the same dimming processing as the luminance expansion units 150 and 151. That is, when the first white peak value is larger than the second white peak value, the dimming processing unit 160 may perform the dimming processing so that the aperture ratio of the dimming unit 192 is reduced.

  In addition, the dimming coefficient generation unit 162 generates not only the second dimming coefficient based on the second feature information or the like but also the first dimming coefficient based on the first feature information or the like, and the dimming control unit If the first white peak value is larger than the second white peak value, 164 may perform dimming using an average value of the first dimming coefficient and the second dimming coefficient.

Further, although the dimming coefficient generation unit 162 generates the dimming coefficient by the same method as the expansion coefficient, the dimming coefficient may be generated based on the expansion coefficient generated by the expansion coefficient generation unit 152. For example, the dimming coefficient generation unit 162 may calculate (1 + applied expansion coefficient / 255) ^−2.2 as the applied dimming coefficient.

  In addition, the above-described dimming is not essential, and the present invention is also effective when only luminance expansion is performed. For example, when only luminance expansion is performed, the light control processing unit 160 and the light control unit 192 are unnecessary.

  The generation target of the feature information is not limited to the entire image, for example, excluding the pixels in the peripheral portion of the image, the pixels in the upper and lower portions of the image, the pixels in the left and right portions of the image, and the pixels in the lower portion of the image. It may be the central block of the image. For example, the feature information generation units 120 and 140 generate the feature information indicating the feature of the image without being affected by the caption even if the image is synthesized with the caption by removing the lower pixel of the image. can do.

  In addition, the present invention may be applied to a display device having an IP conversion unit such as a TV and a liquid crystal monitor other than the projectors 100 and 101. Further, the projectors 100 and 101 are not limited to liquid crystal projectors (transmission type, reflection type such as LCOS), and may be, for example, a projector using DMD (Digital Micromirror Device). DMD is a trademark of Texas Instruments Incorporated. Further, the functions of the projectors 100 and 101 may be distributed and implemented in a plurality of devices (for example, a PC and a projector).

  100, 101 projector (display device), 110 image signal input unit, 120 feature information generation unit (first feature information generation unit), 130 IP conversion unit, 140 feature information generation unit (second feature information generation unit), 150, 151 luminance expansion unit, 152, 153 temporary expansion coefficient generation unit, 154, 155 expansion coefficient determination unit, 156 expansion processing unit, 160 dimming processing unit, 162 dimming coefficient generation unit, 164 dimming control unit, 181 determination , 182 difference value calculation unit, 183 expansion coefficient correction value generation unit, 184 adjustment expansion coefficient generation unit, 185 average value calculation unit, 188, 189 applicable expansion coefficient determination unit, 190 projection unit, 192 dimming unit, 200, 201 Information storage medium

Claims (8)

A first feature information generation unit that generates first feature information related to the brightness of an image based on an image signal before progressive conversion;
A second feature information generation unit that generates second feature information related to the brightness of the image based on the image signal after the progressive conversion;
A luminance expansion unit for performing luminance expansion;
Including
The luminance expansion unit is
A temporary expansion coefficient generation unit that generates a second temporary expansion coefficient based on at least a part of the second feature information;
Depending on the difference between the first brightness value included in the first feature information and the second brightness value included in the second feature information, the second temporary expansion coefficient or the second An expansion coefficient determination unit that determines an adjustment expansion coefficient based on the temporary expansion coefficient as an applicable expansion coefficient;
An expansion processing unit that performs an expansion process on the image signal after the progressive conversion based on the applied expansion coefficient;
including,
Display device. The display device according to claim 1,
The expansion coefficient determination unit
A determination unit that determines whether the first brightness value is greater than the second brightness value;
A difference value calculation unit for calculating a difference value between the first brightness value and the second brightness value;
An expansion coefficient correction value generation unit that generates an expansion coefficient correction value greater than 0 and less than or equal to 1 based on the difference value and the expansion coefficient correction value data;
An adjustment expansion coefficient generation unit configured to generate the adjustment expansion coefficient by multiplying the second temporary expansion coefficient and the expansion coefficient correction value;
When the first brightness value is greater than the second brightness value, the adjustment expansion coefficient is determined as the applied expansion coefficient, and the first brightness value is greater than the second brightness value. An application expansion coefficient determination unit that determines the second temporary expansion coefficient as the application expansion coefficient when it is not large;
including,
Display device. The display device according to claim 1,
The temporary expansion coefficient generating unit generates a first temporary expansion coefficient based on at least a part of the first feature information;
The expansion coefficient determination unit
A determination unit that determines whether the first brightness value is greater than the second brightness value;
An average value calculation unit for calculating an average value of the first temporary expansion coefficient and the second temporary expansion coefficient;
When the first brightness value is larger than the second brightness value, the average value is determined as the applied expansion coefficient, and the first brightness value is larger than the second brightness value. An application expansion coefficient determination unit that determines the second temporary expansion coefficient as the application expansion coefficient when there is not,
including,
Display device. The display device according to any one of claims 1 to 3,
The second feature information generation unit generates at least information indicating a white peak value and information indicating APL as the second feature information.
Display device. The display device according to claim 4,
The temporary expansion coefficient generation unit, based on the expansion coefficient generation data in which the white peak value, the APL, the white peak value, the APL, and the second temporary expansion coefficient are associated with each other. Generate a temporary expansion factor of 2;
Display device. The display device according to any one of claims 1 to 5,
A dimming unit that performs dimming based on the second feature information or the applied expansion coefficient;
Display device. Computer
A first feature information generation unit that generates first feature information related to the brightness of an image based on an image signal before progressive conversion;
A second feature information generation unit that generates second feature information related to the brightness of the image based on the image signal after the progressive conversion;
It functions as a luminance expansion unit that performs luminance expansion,
The luminance expansion unit is
A temporary expansion coefficient generation unit that generates a second temporary expansion coefficient based on at least a part of the second feature information;
Depending on the difference between the first brightness value included in the first feature information and the second brightness value included in the second feature information, the second temporary expansion coefficient or the second An expansion coefficient determination unit that determines an adjustment expansion coefficient based on the temporary expansion coefficient as an applicable expansion coefficient;
An expansion processing unit that performs an expansion process on the image signal after the progressive conversion based on the applied expansion coefficient;
including,
program. An information storage medium storing a computer-readable program,
An information storage medium storing the program according to claim 7.

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