EP4760702A1

EP4760702A1 - Display driving method and display driving device

Info

Publication number: EP4760702A1
Application number: EP24852274.0A
Authority: EP
Inventors: Seul Gi Lee; Ji Min Seo; Jun Young Park; Min Ji Lee
Original assignee: LX Semicon Co Ltd
Current assignee: LX Semicon Co Ltd
Priority date: 2023-08-10
Filing date: 2024-08-06
Publication date: 2026-06-17
Also published as: WO2025033920A1; CN121693774A; KR20250023705A

Abstract

A display driving method according to embodiments may comprise the steps of: measuring the luminance of a panel; calculating a look up table (LUT) on the basis of the measured luminance; and calculating a low gray value and a high gray value for a target luminance on the basis of the LUT. A display driving device according to embodiments may comprise: a measurement unit for measuring the luminance of a panel; a first calculation unit for calculating a look up table (LUT) on the basis of the measured luminance; and a second calculation unit for calculating a low gray value and a high gray value for a target luminance on the basis of the LUT.

Description

TECHNICAL FIELD

The present embodiments relate to a display driving method and a display driving device.

BACKGROUND ART

Viewing angle performance of a display panel is important. In the case of a display panel with poor viewing angle performance, a problem may occur in that display color quality deteriorates when viewing the display panel from the front or from the side. Accordingly, a display driving method that compensates for viewing angle performance of a display panel is required.

DISCLOSURE

TECHNICAL PROBLEM

Embodiments provide a display driving method and a display driving device for accurately and efficiently performing degradation compensation.
Embodiments provide a display driving method and a display driving device that achieve high color quality and solve the problem of image quality deterioration due to color fading.
However, the technical objects of the embodiments are not limited to the aforementioned technical problems, and the scope of the embodiments may be extended to other technical objects that can be inferred by those skilled in the art based on the entire description.

TECHNICAL SOLUTION

A display driving method according to embodiments may include measuring luminance of a panel; calculating a LUT (Look Up Table) based on the measured luminance; and calculating low gray (Low Gray) and high gray (High Gray) values for a target luminance based on the LUT. A display driving device according to embodiments may include a measurement unit configured to measure luminance of a panel; a first calculation unit configured to calculate a LUT (Look Up Table) based on the measured luminance; and a second calculation unit configured to calculate low gray (Low Gray) and high gray (High Gray) values for a target luminance based on the LUT.

EFFECT OF THE INVENTION

A method and a device according to embodiments may drive a display with high quality.
A method and a device according to embodiments may provide a display having excellent viewing angle performance.
A method and a device according to embodiments can adaptively control the intensity of panel output efficiently and with low complexity.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the embodiments, and are incorporated in and constitute a part of this specification. For a better understanding of the various embodiments described below, reference should be made to the following description of the embodiments in connection with the following drawings, in which like reference numerals refer to corresponding parts throughout the drawings.

FIG. 1 illustrates a display driving device according to embodiments.
FIG. 2 illustrates a luminance measurement and LUT calculation method according to embodiments.
FIG. 3 illustrates a target index calculation method according to embodiments.
FIGS. 4A AND 4B illustrate a VWC level determination method according to embodiments.
FIG. 5 illustrates a VWC level determination method according to an embodiment.
FIG. 6 illustrates the effects of a display driving method according to embodiments.
FIG. 7 illustrates a display driving device according to embodiments.
FIG. 8 illustrates a display driving method according to embodiments.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawings. The detailed description set forth below in connection with the accompanying drawings is intended as a description of the preferred embodiments and is not intended to represent the only embodiments that may be implemented in accordance with the embodiments. The following detailed description includes specific details to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that the embodiments may be practiced without these specific details.
Most of the terms used in the embodiments are selected from general terms widely used in the corresponding field, but some terms are arbitrarily selected by the applicant and their meanings will be described in detail in the following description as necessary. Therefore, the embodiments should be understood based on the intended meanings of the terms, rather than their simple names or dictionary meanings.
FIG. 1 illustrates a display driving device according to embodiments.
The display driving device of FIG. 1 may include a first calculation unit 100 and/or a second calculation unit 101. The first calculation unit 100 may be referred to as a look-up table (LUT) calculation unit. The second calculation unit 101 may be referred to as an INDEX calculation unit. Each component of the display driving device according to embodiments may correspond to hardware, software, a processor, and/or a combination thereof. For example, the first calculation unit 100 may be software, and the second calculation unit 101 may be hardware. The first calculation unit 100 may be a system including a memory including instructions for LUT calculation, and a processor configured to perform LUT calculation operation and high gray/low gray calculation operation based on the instructions stored in the memory.
The display driving method/device according to embodiments may perform VWC (Adaptive VA panel Washout Compensation). The display driving device according to embodiments may correspond to a display control device such as a T-CON or a SoC (System on Chip).
The display driving method/device according to embodiments may compensate for a disadvantage of poor viewing angle performance in an LCD VA panel. For example, a LUT may be generated using characteristics with a good viewing angle at low gray/high gray gamma, and compensation may be performed using the LUT.
The display driving method/device according to embodiments may measure luminance information of a panel. An LUT for outputting high gray (High)/low gray (Low) pixel values may be generated using the measured luminance information of the panel. In addition, the intensity of the High/Low output may be adaptively controlled by analyzing an image in terms of saturation and edge.
Among LCD panels, a VA panel may have inferior viewing angle characteristics compared to an IPS panel. While IPS panels has excellent viewing angle characteristics, VA panels have narrow viewing angle characteristics. Therefore, when viewing a VA panel from both sides or from above or below, color reproduction may be poor, and image quality may deteriorate. Although the viewing angle is compensated by physically dividing the domain of the display, there are limitations. To improve the narrow viewing angle of the VA panel, a multi-domain liquid crystal arrangement is employed. However, limitations in the viewing angle still remain, and there is a trade-off in which transmittance decreases as the number of domains increases. The conventional method of separately using LUTs for high gray (High) and low gray (Low) has limitations in terms of memory. By utilizing the superior viewing angle characteristics in low gray (Low) or high gray (High) gamma, it is possible to improve the viewing angle characteristics by dividing the luminance of one pixel into high gray (High) and low gray (Low) portions and driving them accordingly. In this case, separate High/Low LUTs may be required. To achieve accurate and adaptive compensation according to the input image using fixed High/Low LUTs, addition memory may be necessary. Therefore, there is a need for a method that reduces the use of additional memory or complex logic. A memory-saving effect can be achieved by using an integrated method that does not require separate High/Low LUTs. The degree of High/Low can be set by the user, and the intensity can also be easily adjusted according to the levels of saturation and edge.
Referring to FIG. 1, the display driving method according to embodiments may include a method of setting High and Low without High/Low LUTs.
For example, in order to generate a specific luminance, Low/High are set at equal intervals along the luminance axis to determine corresponding gray values. Accordingly, values corresponding to Low/High may be obtained from a single LUT. Intensities of Low/High may be set according to embodiments.
Specifically, the display driving method according to embodiments measures luminance. Luminance of the panel is measured. The measured luminance value of the panel may be received. As shown in FIG. 1, the measured luminance values may be expressed with a gray (component on X-axis) and a luminance (component on Y-axis).
The display driving method according to embodiments generates a LUT. For example, the measured luminance values are normalized, and corrections are applied to generate the LUT. Here, the LUT calculation operation may be performed by software.
The display driving method according to embodiments performs index (INDEX) calculation. Using the generated LUT values, the Low/High Gray values are derived according to a target luminance through the index calculation. Here, the index calculation may be performed by hardware.
Referring to FIG. 1, the LUT calculation unit receives the measured luminance of the panel, normalizes it, and applies compensation to generate a LUT. The index calculation unit calculates High/Low gray for a target luminance by performing index calculation based on the LUT. Here, H pixel data and L pixel data are generated. Hereinafter, a detailed description will be given with reference to the respective drawings.
FIG. 2 illustrates in detail the luminance measurement and LUT calculation process shown in FIG. 1.
FIG. 2 illustrates the luminance measurement and LUT calculation process of FIG. 1 in detail. The luminance measurement and LUT calculation method of the display driving method according to embodiments may measure luminance across all grays, remove luminance inversion (that is, remove sections where inversion occurs in the measured data), and perform data smoothing to compensate.
Specifically, in S201, the display driving device according to embodiments receives the measured luminance data. In S202, the display driving device according to embodiments corrects the data. For example, luminance inversion is removed, and data smoothing is applied to correct the data. In S203, the display driving device according to embodiments performs data normalization. For example, a LUT is generated through normalization or extension. The generated LUT may be referred to as a first LUT or a target LUT. Additionally, an inverse LUT of the LUT is generated. The inverse LUT may be referred to as a second LUT or an inverse target LUT.
Referring to FIG. 2, the display driving method according to embodiments may measure luminance across all grays, and determine a gamma 2.2 target based on a corresponding target maximum (Target max). Based on the gamma 2.2 target, targets may then individually be obtained, and a LUT may be calculated accordingly. In addition, LUT correction may be performed to address luminance inversion, bending points in the graph, and the like. This target calculation can be expressed by the following equation: Target[i] = Target max * (i/255)^2.2.
FIG. 3 illustrates a target index calculation method according to embodiments.
FIG. 3 illustrates in detail the target index calculation method in the display driving method of FIG. 1. The display driving device according to embodiments determines H/L for an arbitrary X gray (target X gray). That is, as described with reference to FIG. 2, a luminance Y for X may be extracted from the generated target LUT. This process can be expressed by the equation: f(X)=Y. The display driving device according to embodiments determines H/L based on the Y according to the VWC level. Here, H (high) corresponds component a in FIG. 3, and L (low) corresponds component b in FIG. 3. This can be expressed by the equations: a=Y+VWC level, b=Y-VWC level. In other words, luminance data is measured from the actual panel, corrected and normalized to obtain accurate luminance data, a LUT and an inverse LUT are generated based on the measured values, and high gray and low gray are determined through index calculation. The display driving device according to embodiments determines a gray value based on the calculated a and b components. Specifically, "" component and "" component for a and b components are extracted from the inverse LUT, respectively. This can be expressed by the equations: L-1(a)= (Gray for High), L-1(b)= (Gray for Low).
FIGS. 4A AND 4B illustrate a VWC level determination method according to embodiments.
FIGS. 4A AND 4B show a method of determining the VWC level in detail, as described in FIG. 3.
Referring to FIGS. 4A AND 4B, the VWC level is determined based on the minimum value of luminance of the panel gamma for each gray. For example, the maximum VWC level may be equal to the minimum value, Min(a, b), VWC Level Max = Minimum Value (Min (a, b)). When determined based on this minimum value, an inflection point appears in the curve, as illustrated in FIGS. 4A AND 4B.
In the graph of FIGS. 4A AND 4B, the X-axis represents Gray (RGB Data), and the Y-axis represents a luminance value.
The maximum value of the panel luminance is calculated as follows: VWC Level Max = Minimum Value (Min (a, b)).
In this case, a roll-off point is set to generate a nonlinear curve, and the roll-off point is established as ±Gray relative to the inflection point. In other word, the roll-off application section ranges from (the inflection point - Gray position) to (the inflection point + Gray position), where ±Gray may be set as a parameter. The nonlinear curve has a symmetrical shape with respect to the inflection point. The equation for setting VWC roll-off according to embodiments is as follows:
$VWC Roll - Off = Offset + VWC level Diff * {(\frac{Input Gray - Roll Off Start Gray}{Roll Off Width})}^{RollOff_Weight}$
VWC intensity (VWC level) may be adjusted according to saturation, edge, input gray, and the like. For example, a relationship such as VWC level 1 > VWC level 2 may be established. The VWC intensity (VWC level) may be set as the following equation:
$VWC level = VWC Gain * Saturation Gain * Edge Gain * VWC Roll - off$
The definitions and functions of the variables in the above equation according to embodiments are as follows.
Roll-off (VWC Roll-Off): The reason why the roll-off function is added is to make a sharp point smooth (that is, since sharp points may cause artifacts when gradation is present on the panel, roll-off is applied to prevent this).
Offset: The Y-axis value corresponding to the roll-off start gray.
Level interval (VWC level Diff): The Y-axis interval in the section where the roll-off is applied.
Input gray: The RGB data input to each pixel of the panel.
Roll-off start gray: The X-axis value at the starting point where the roll-off is applied.
Roll-off width: The X-axis interval in the section where the roll-off is applied.
Roll-off_weight: A value that adjusts the intensity of the curve at the sharp point (Sharp Point).
Referring to FIGS. 4A AND 4B shows the distribution of the panel measurement values (target Lv) and Min(a,b) (the minimum value between variables a and b).
The maximum value for the panel measurement value may be determined as follows:
$TargetLv_L_\max = Target Lv - \min (a, b)$
Around the inflection point, roll-off may be calculated as follows. $VWC Roll - Off = Offset + VWC level Diff * {(\frac{Input Gray - Roll Off Start Gray}{Roll Off Width})}^{RollOff_Weight}$
The VWC Level cannot be set to be larger than the minimum value for each Gray calculated previously.
The display driving method according to embodiments may generate the VWC level (intensity) at equal intervals.
Referring to FIGS. 4A AND 4B, in order to generate a level for high gray calculation and a level for low gray calculation to be equal to each other, a VWC (equal interval) level may be generated based on the VWC gain, saturation gain, edge gain, VWC roll-off value for reflecting the inflection point, and the like, as in the above described equation.
In the VWC level determination method, the definition and function of each parameter are as follows.
Gain (VWC Gain): A value that determines how much difference is made between high gray/low gray (High/Low) values.
Saturation gain: It has a function of adjusting the VWC intensity according to the saturation of each pixel, and is a value indicating the degree of saturation (Saturation).
Edge gain: It has a function of adjusting the VWC intensity according to the degree of edge of each pixel, and is a value indicating the degree of edge (VWC intensity: degree of difference between High/Low).
The minimum parameters used for level calculation are VWC Gain (for adjusting High/Low intensity) and VWC roll-off (necessary to prevent artifacts caused by sharp points). Saturation Gain and Edge Gain may be implemented to enable On/Off, and may be optional according to embodiments.
FIG. 5 illustrates a VWC level determination method according to embodiments.
In order to further explain FIGS. 4A AND 4B, referring to FIG. 5, embodiments may determine a VWC level in FIGS. 4A AND 4B, calculate high gray and low gray through the determined level, and determine a gray value for each of high gray and low gray through a LUT as shown in FIG. 5.
For example, assuming VWC level 1 and VWC level 2 for explanation, when level 1 is calculated through the above-described process according to embodiments, level 1 is applied at equal intervals to compute h1, which is a gray value for high gray H1. Similarly, 11, which is a gray value for low gray L1, is computed. Likewise, when level 2 is calculated, level 2 is applied at equal intervals to compute h2, which is a gray value for high gray H2, and 12, which is a gray value for low gray L2, may be efficiently computed. In this manner, by utilizing a single target LUT without additional memory burden and without the need for complex system design or operations, the display panel output intensity can be adaptively controlled at equal intervals.
FIG. 6 illustrates the effects of a display driving method according to embodiments.
FIG. 6 shows the effects of the display driving method described in FIGS. 1 to 5 in detail.
Referring to FIG. 6, regarding the gamma component for the front view of the display, a graph is shown comparing the case where VWC according to the embodiments is applied and the case where it is not applied. FIG. 6 illustrates a comparison of display panel screen images depending on whether VWC is applied. From a side viewing angle, it can be seen that the display colors become clearer (or more vivid) when VWC is applied.
FIG. 7 illustrates a display driving device according to embodiments.
FIG. 7 corresponds to the display driving device of FIG. 1. The LUT calculation unit 100 of a display driving device of FIG. 7 may include a BEP (Boundary Edge Preservation), an ASG (Adaptive Saturation Gain), and/or an EPP (Edge Pattern Preservation). The H/L index calculation unit 101 calculates high gray and low gray based on the operation described above. A H/L DGA (DeGamma) calculates high gray and low gray for the gamma component through the VWC level by means of degamma as illustrated in FIGS. 4 and 5.
FIG. 8 illustrates a display driving method according to embodiments.
FIG. 8 shows the display driving method described in FIG. 1 and the like.
In S800, the display driving method according to embodiments may include measuring luminance of the panel. The luminance measurement operation follows the description in FIG. 1 and the like.
In S801, the display driving method according to embodiments may further include calculating a LUT. The LUT calculation operation follows the description in FIGS. 1 to 2 and the like.
In S802, the display driving method according to embodiments may further include calculating Low/High Gray values according to a target luminance based on an index calculation. The Gray value calculation operation follows the description in FIGS. 3 to 5 and the like.
Referring to FIGS. 1 and 8, the display driving method may include: measuring luminance of the panel; calculating a LUT (Look Up Table) based on the measured luminance; and calculating Low Gray and High Gray values for a target luminance based on the LUT.
Referring to FIG. 1, in relation to the panel luminance measurement, the step of measuring luminance of a panel may include:
measuring the luminance based on gray and luminance obtained from the panel.
Referring to FIG. 2, regarding the calculation of a LUT, the step of calculating the LUT (Look Up Table) may include removing an inversion section from the measured luminance; applying smoothing to the luminance; and normalizing the luminance, wherein a first LUT and a second LUT may be generated based on the luminance, and the second LUT may be an inverse of the first LUT. Since generating and using LUTs requires memory usage, a method that generates and operates with a minimum number of LUTs contributes to efficient memory utilization and reduces complexity and cost in system design.
Referring to FIG. 3, regarding the target index calculation, the step of calculating Low Gray and High Gray values may include: extracting luminance corresponding to a specific gray value based on a first LUT calculated from the measured luminance, obtaining a high gray value corresponding to a value obtained by adding a level to the luminance from a second LUT that is an inverse of the first LUT, and obtaining a low gray value corresponding to a value obtained by subtracting the level from the luminance from the second LUT that is an inverse of the first LUT, wherein the level associated with the high gray value and the level associated with the low gray value may be equal to each other.
Referring to FIGS. 4A AND 4B, regarding the determination of the VWC level, the level is generated based on the minimum luminance value of the panel gamma for each gray.
Referring to FIGS. 4A AND 4B, regarding the curve inflection point roll-off, a section where the luminance value with respect to gray has an inflection point is adjusted based on an offset. A term "roll-off" is interpreted as meaning smoothing a steep variation section at the inflection point into a smooth curve form.
The display driving method is performed by the display driving device. Referring to FIG. 1, the display driving device includes: a measurement unit configured to measure luminance of the panel; a first calculation unit configured to calculate a LUT (Look Up Table) based on the measured luminance; and a second calculation unit configured to calculate low gray (Low Gray) and high gray (High Gray) values for a target luminance based on the LUT. The measurement unit measures luminance based on gray and luminance obtained from the panel. The first calculation unit removes an inversion section from the measured luminance, applies smoothing to the luminance, and normalizes the luminance, wherein a first LUT and a second LUT are generated based on the luminance, and the second LUT is an inverse of the first LUT.
The second calculation unit extracts luminance corresponding to a specific gray value based on the first LUT calculated from the measured luminance, obtains a high gray value corresponding to a value obtained by adding a level to the luminance from the second LUT that is an inverse of the first LUT, and obtains a low gray value corresponding to a value obtained by subtracting a level from the luminance from the second LUT that is an inverse of the first LUT, wherein the level associated with the high gray value and the level associated with the low gray value are equal to each other. The level is generated based on the minimum luminance value of the panel gamma for each gray (for a detailed method of calculating the level, refer to the above-described method (equation(s)).
A section where the luminance value with respect to gray has an inflection point is adjusted based on an offset. For the value used for roll-off, refer to the above described method (equation(s)).
Referring to FIG. 1, regarding the processor of the LUT calculation unit, a system may include a memory; and a processor connected to the memory, wherein the processor measures the luminance of the panel, calculates a LUT (Look Up Table) based on the measured luminance, and calculates low gray (Low Gray) and high gray (High Gray) values for a target luminance based on the LUT. In an embodiment, the display device may include a panel and the system. For example, the panel may be an LCD panel, and may also be a VA panel.
The processor measures luminance based on gray and luminance obtained from the panel. The processor removes an inversion section from the measured luminance, applies smoothing to the luminance, and normalizes the luminance, wherein a first LUT and a second LUT are generated based on the luminance, and the second LUT is an inverse of the first LUT. The processor extracts luminance corresponding to a specific gray value based on a first LUT calculated from the measured luminance, obtains a high gray value corresponding to a value obtained by adding a level to the luminance from the second LUT that is an inverse of the first LUT, and obtains a low gray value corresponding to a value obtained by subtracting a level from the luminance from the second LUT that is an inverse of the first LUT, wherein the level associated with the high gray value and the level associated with the low gray value are equal to each other. The level is generated based on the minimum luminance value of the panel gamma for each gray.
The embodiments have been described in terms of a method and/or an apparatus, and the description of the method and the description of the apparatus may be complementarily applied.
Although each drawing has been described separately for convenience of explanation, it is also possible to design and implement new embodiments by merging the embodiments described in each drawing. In addition, providing a computer-readable recording medium on which a program for executing the previously described embodiments is recorded according to the needs of those skilled in the art also falls within the scope of the embodiments. The apparatus and methods according to the embodiments are not limited to the configurations and methods of the described embodiments, but the embodiments may be configured by selectively combining all or part of each embodiment so that various modifications can be made. Although preferred embodiments of the embodiments have been shown and described, the embodiments are not limited to the specific embodiments described above, and various modifications can be made by those of ordinary skill in the art to which the present invention pertains without departing from the gist of the embodiments claimed in the claims. Of course, these modifications should not be interpreted separately from the technical spirit or prospects of the embodiments.
Various components of the apparatus of the embodiments may be implemented by hardware, software, firmware, or a combination thereof. Various components of the embodiments may be implemented as a single chip, for example, a single hardware circuit. Depending on the embodiments, components according to the embodiments may be implemented as separate chips. Depending on the embodiments, at least one or more of the components of the apparatus according to the embodiments may be composed of one or more processors capable of executing one or more programs, and the one or more programs may perform any one or more of the operations/methods according to the embodiments or may include instructions for performing them. Executable instructions for performing the methods/operations of the apparatus according to the embodiments may be stored in a non-transitory CRM or other computer program products configured to be executed by one or more processors, or may be stored in a transitory CRM or other computer program products configured to be executed by one or more processors. Also, the memory according to the embodiments may be used as a concept that includes not only volatile memory (e.g., RAM, etc.) but also non-volatile memory, flash memory, PROM, etc. In addition, implementation in the form of a carrier wave, such as transmission over the Internet, may also be included. In addition, the processor-readable recording medium may be distributed in a networked computer system, so that the processor-readable code may be stored and executed in a distributed manner.
In this document, "/" and "," are interpreted as "and/or." For example, "A/B" is interpreted as "A and/or B," and "A, B" is interpreted as "A and/or B." Additionally, "A/B/C" means "at least one of A, B, and/or C." Also, "A, B, C" also means "at least one of A, B, and/or C." Additionally, in this document, "or" is interpreted as "and/or." For example, "A or B" can mean 1) only "A," 2) only "B," or 3) "A and B." In other words, "or" in this document can mean "additionally or alternatively. "
Terms such as first, second, etc. may be used to describe various components of the embodiments. However, various components according to the embodiments should not be interpreted as limited by the above terms. These terms are merely used to distinguish one component from another component. For example, a first user input signal may be referred to as a second user input signal. Similarly, the second user input signal may be referred to as the first user input signal. The use of these terms should be interpreted as not departing from the scope of the various embodiments. Both the first user input signal and the second user input signal are user input signals, but they do not mean the same user input signals unless clearly indicated in the context.
The terminology used to describe the embodiments is used for the purpose of describing specific embodiments and is not intended to limit the embodiments. As used in the description and claims of the embodiments, the singular is intended to include the plural unless the context clearly indicates otherwise. The expression "and/or" is used to mean all possible combinations between terms. The expression "comprises" describes the presence of features, numbers, steps, elements, and/or components, and does not preclude the presence of additional features, numbers, steps, elements, and/or components are excluded. Conditional expressions such as "in the case of' and "when" used to describe the embodiments are not construed as limiting to optional cases only. When a specific condition is met, it is intended that a related operation is performed in response to the specific condition or that a related definition is interpreted.
In addition, operations according to the embodiments described in this document may be performed by a transmission/reception device including a memory and/or a processor according to the embodiments. The memory may store programs for processing/controlling operations according to the embodiments, and the processor may control various operations described in this document. The processor may be referred to as a controller or the like. Operations in the embodiments may be performed by firmware, software, and/or a combination thereof, and the firmware, software, and/or combination thereof may be stored in the processor or may be stored in the memory.
Meanwhile, the operations according to the above-described embodiments may be performed by the transmission device and/or the reception device according to the embodiments. The transmission/reception device may include a transceiver for transmitting and receiving media data, a memory for storing instructions (program code, algorithm, flowchart, and/or data) for the process according to the embodiments, and a processor for controlling the operations of the transmission/reception device.
The processor may be referred to as a controller or the like, and may correspond to, for example, hardware, software, and/or a combination thereof. The operations according to the above-described embodiments may be performed by the processor. In addition, the processor may be implemented as an encoder/decoder or the like for the operations of the above-described embodiments.
As described above, the related contents have been described in the best mode for carrying out the embodiments.
As described above, the embodiments can be applied wholly or partially to digital image transmission/reception devices and systems.
Those skilled in the art may variously change or modify the embodiments within the scope of the embodiments.
The embodiments may include changes/modifications, and the changes/modifications do not depart from the scope of the claims and equivalents thereof.

Claims

A display driving method comprising:
measuring luminance of a panel;

calculating a LUT (Look Up Table) based on the measured luminance; and

calculating low gray (Low Gray) and high gray (High Gray) values for a target luminance based on the LUT.
The method according to claim 1, wherein said measuring luminance of a panel includes:
measuring the luminance based on gray and luminance obtained from the panel.
The method according to claim 1, wherein said calculating a LUT (Look Up Table) includes:
removing an inversion section from the measured luminance,

applying smoothing to the luminance, and

normalizing the luminance, and

wherein a first LUT and a second LUT are generated based on the luminance, and

the second LUT is an inverse of the first LUT.
The method according to claim 1, wherein said calculating Low Gray and High Gray values includes:
extracting luminance corresponding to a specific gray value based on a first LUT calculated based on the measured luminance,

obtaining a high gray value corresponding to a value obtained by adding a level to the luminance from a second LUT that is an inverse of the first LUT, and

obtaining a low gray value corresponding to a value obtained by subtracting the level from the luminance from the second LUT that is an inverse of the first LUT,

wherein the level associated with the high gray value and the level associated with the low gray value are equal to each other.
The method according to claim 4, wherein the level is generated based on the minimum luminance value of the panel gamma for each gray.
The method according to claim 5, wherein a section where the luminance value with respect to gray has an inflection point is adjusted based on an offset.
A display driving device comprising:
a measurement unit configured to measure luminance of a panel;

a first calculation unit configured to calculate a LUT (Look Up Table) based on the measured luminance; and

a second calculation unit configured to calculate low gray (Low Gray) and high gray (High Gray) values for a target luminance based on the LUT.
The display driving device according to claim 7, wherein the measurement unit is configured to measure the luminance based on gray and luminance obtained from the panel.
The display driving device according to claim 7, wherein the first calculation unit is configured to:
remove an inversion section from the measured luminance,

apply smoothing to the luminance, and

normalize the luminance, and

wherein a first LUT and a second LUT are generated based on the luminance, and

the second LUT is an inverse of the first LUT.
The display driving device according to claim 7, wherein the second calculation unit is configured to:
extract luminance corresponding to a specific gray value based on a first LUT calculated from the measured luminance,

obtain a high gray value corresponding to a value obtained by adding a level to the luminance from a second LUT that is an inverse of the first LUT, and

obtain a low gray value corresponding to a value obtained by subtracting a level from the luminance from the second LUT that is an inverse of the first LUT,

wherein the level associated with the high gray value and the level associated with the low gray value are equal to each other.
The display driving device according to claim 10, wherein the level is generated based on the minimum luminance value of the panel gamma for each gray.
The display driving device according to claim 11, wherein a section where the luminance value with respect to gray has an inflection point is adjusted based on an offset.
A display device comprising:
a panel;

a memory; and

a processor connected to the memory,

wherein the processor is configured to:
measure luminance of a panel,

calculate a LUT (Look Up Table) based on the measured luminance, and

calculated to low gray (Low Gray) and high gray (High Gray) values for a target luminance based on the LUT.
The display device according to claim 13, wherein the processor is configured to measure the luminance based on gray and luminance from the panel.
The display device according to claim 13, wherein the processor is configured to:
remove an inversion section from the measured luminance,

apply smoothing to the luminance, and

normalize the luminance, and

wherein a first LUT and a second LUT are generated based on the luminance, and

the second LUT is an inverse of the first LUT.
The display device according to claim 13, wherein the processor is configured to:
extract luminance corresponding to a specific gray value based on a first LUT calculated from the measured luminance,

obtain a high gray value corresponding to a value obtained by adding a level to the luminance from a second LUT that is an inverse of the first LUT, and

obtain a low gray value corresponding to a value obtained by subtracting a level from the luminance from the second LUT that is an inverse of the first LUT,

wherein the level associated with the high gray value and the level associated with the low gray value are equal to each other.
The display device according to claim 16, wherein the level is generated based on the minimum luminance value of panel gamma for each gray.
The display device according to claim 17, wherein a section where the luminance value with respect to gray has an inflection point is adjusted based on an offset.