KR20180024825A - Display device and method of driving the same - Google Patents

Abstract

A display device and a method of driving the display device are provided. A method of driving a display device includes generating a shadow map using video data for an original image, computing a shadow gain for the shadow thickness and size in the shadow map, applying a shadow gain to the video data for the original image Computing a global feedback gain based on video data for the original image and shadow data applied to the original image before the shadow gain is applied, and calculating global feedback gain based on the global feedback gain on the video data for the original image to which the shadow gain is applied, And applying a gain. Thus, the stereoscopic effect of the image is improved, the sharpness of the image is enhanced, and the image quality can be improved.

Description

DISPLAY DEVICE AND METHOD OF DRIVING THE SAME [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device and a display device driving method, and more particularly, to a display device and a display device driving method capable of improving three-dimensional feeling in a two-dimensional image and improving sharpness.

Various methods of sharpness enhancement, which is a method for improving image clarity by displaying images more clearly, have already been known. As a conventional sharpness improvement method, there is a case where image processing is performed in such a manner that an edge such as an outline in an image is obtained and the edges are weakened while emphasizing the edge. As a specific example of the image processing for emphasizing an edge as described above, an unsharp mask process can be mentioned. However, conventional sharpness improving methods such as unsharp mask and the like have an advantage of improving overall sharpness, but side effects such as clipping or noise may occur.

Meanwhile, in recent years, studies have been made not only to improve the sharpness of the image but also to make the user feel improved three-dimensional feeling in the two-dimensional image. However, the edge-based sharpness improving method such as the above-described unsymmetric mask can improve not only the sharpness of the image but also the stereoscopic effect of the image.

Accordingly, there is a need for an image processing technique for improving the sharpness of a two-dimensional image as well as an image processing technique for improving sharpness over conventional sharpness improving methods such as an unsharp mask and the like.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a display device and a display device capable of improving the sharpness of an image as well as enhancing a sensory sense of three- Method.

Another object of the present invention is to provide a display device and a display device driving method capable of removing a ghost phenomenon and an artifact which may occur in the process of using a shadow map by applying various gains .

The problems of the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, a method of driving a display device according to an embodiment of the present invention is provided. A method of driving a display device includes generating a shadow map using video data for an original image, computing a shadow gain for the shadow thickness and size in the shadow map, applying a shadow gain to the video data for the original image Calculating a global feedback gain based on video data for the original image before the shadow gain is applied and the original image for which the shadow gain is applied, and calculating a global feedback gain for the video data for the original image to which the shadow gain is applied, . ≪ / RTI > Thus, the stereoscopic effect of the image is improved, the sharpness of the image is enhanced, and the image quality can be improved.

According to an aspect of the present invention, there is provided a display device including: The display device includes a display panel, a shadow map generator, a shadow gain calculator, and a global feedback gain calculator. The shadow map generating unit generates a shadow map using the video data on the original image to be provided on the display panel. The shadow gain computing unit computes the shadow gain for the shadow thickness and size in the shadow map, and applies the shadow gain to the video data for the original image. The global feedback gain computing unit computes the global feedback gain based on the video data of the original image before the shadow gain is applied and the video data of the original image to which the shadow gain is applied and outputs the global feedback gain to the video data of the original image to which the shadow gain is applied, Applies the feedback gain, and provides the display panel with video data for the original image to which the shadow gain and global feedback gain are applied. Therefore, the shadow gain for the thickness and size of the shadow is applied to the original image, so that the user can feel an improved sense of depth. In addition, artifacts that may unintentionally occur in the course of improving the three-dimensional effect and sharpness can be minimized by applying global feedback gain.

The details of other embodiments are included in the detailed description and drawings.

The present invention can provide a more realistic image quality to a user by giving a more improved stereoscopic effect to a two-dimensional image.

In addition, the present invention not only improves the stereoscopic effect of an image, but also improves the image quality by improving the sharpness of the image, and also enhances the immersion feeling of the user.

In addition, the present invention can improve the three-dimensional feeling that the user can feel by applying the shadow gain to the thickness and the size of the shadow.

In addition, the present invention can minimize the artifacts that may occur in improving the sharpness of an image by applying a global feedback gain to the entire image.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the specification.

1 is a block diagram for explaining a display device according to an embodiment of the present invention.
2 is a block diagram for explaining the timing controller shown in FIG.
3 is a flowchart illustrating a method of driving a display device according to an embodiment of the present invention.
4A and 4B are images for explaining a process of generating a shadow map.
5 is a graph for explaining the shadow gain in the display device driving method according to an embodiment of the present invention.
6 is a graph for explaining the shadow gain in the display device driving method according to another embodiment of the present invention.
7 is a graph for explaining a global feedback gain in a method of driving a display device according to an embodiment of the present invention.
8 is a graph for explaining a global feedback gain in a display device driving method according to another embodiment of the present invention.
9 is a block diagram illustrating a display device according to another embodiment of the present invention.
10 is a flowchart illustrating a method of driving a display device according to another embodiment of the present invention.
11 is a block diagram for explaining a display device according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings for describing the embodiments of the present invention are illustrative, and thus the present invention is not limited thereto. Like reference numerals refer to like elements throughout the specification. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Where the terms "comprises", "having", "done", and the like are used in this specification, other portions may be added unless "only" is used. Unless the context clearly dictates otherwise, including the plural unless the context clearly dictates otherwise.

In interpreting the constituent elements, it is construed to include the error range even if there is no separate description.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is not used, one or more other portions may be located between the two portions.

An element or layer is referred to as being another element or layer "on ", including both intervening layers or other elements directly on or in between.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are used only to distinguish one component from another. Therefore, the first component mentioned below may be the second component within the technical spirit of the present invention.

Like reference numerals refer to like elements throughout the specification.

The sizes and thicknesses of the individual components shown in the figures are shown for convenience of explanation and the present invention is not necessarily limited to the size and thickness of the components shown.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other partially or entirely and technically various interlocking and driving is possible as will be appreciated by those skilled in the art, It may be possible to cooperate with each other in association.

Various embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

1 is a block diagram for explaining a display device according to an embodiment of the present invention. 2 is a block diagram for explaining the timing controller shown in FIG. 1 and 2, the display device 100 includes a timing controller 110, a gate driver 130, a data driver 120, and a display panel 140. Although the display panel 140 is a liquid crystal display panel and the display device 100 is a liquid crystal display device including a liquid crystal display panel, the types of the display panel 140 and the display device 100 are not limited thereto Do not.

The display panel 140 has a structure in which a liquid crystal layer is disposed between two substrates. A plurality of data lines DL and a plurality of gate lines GL cross the lower substrate of the display panel 140. A plurality of pixels can be defined by arranging the liquid crystal cells in a matrix form on the display panel 140 by the intersection structure of the data line DL and the gate line GL. A data line DL, a gate line GL, a thin film transistor, a pixel electrode of a liquid crystal cell connected to the thin film transistor, a storage capacitor, and the like may be formed on a lower substrate of the display panel 140.

A black matrix, a color filter, and a common electrode may be formed on the upper substrate of the display panel 140. The common electrode may be formed on the upper substrate in a vertical electric field system such as a TN (Twisted Nematic) mode and a VA (Vertical Alignment) mode. However, the common electrode may be formed in a horizontal electric field system such as an IPS (In Plane Switching) mode and an FFS (Fringe Field Switching) May be formed on the lower substrate together with the pixel electrode. An alignment film may be formed on each of the upper substrate and the lower substrate of the display panel 140 to attach a polarizing plate and set a pre-tilt angle of the liquid crystal on the inner surface in contact with the liquid crystal.

The data driver 120 may include a plurality of source driver ICs. The data driver 120 can latch the digital video data R'G'B 'under the control of the timing controller 110. [ The data driver 120 may convert the digital video data R'G'B 'into a positive / negative polarity analog data voltage using a positive / negative gamma compensation voltage and supply the same to the data line DL have.

The gate driver 130 may include a plurality of gate driver ICs. The gate driver 130 may include a level shifter and an output buffer for converting the output signals of the shift register and the shift register into a swing width suitable for driving the thin film transistor of the liquid crystal cell. The gate driver 130 may sequentially output a gate pulse (or a scan pulse) having a pulse width of approximately one horizontal period, which is composed of a plurality of gate drive integrated circuits, and supplies the gate pulse to a gate line GL.

The timing controller 110 may control the data driver 120 and the gate driver 130. The timing controller 110 receives digital video data RGB and timing signals Vsync, Hsync, DE, and DCLK from the system board through an interface such as a Low Voltage Differential Signaling (LVDS) interface and a Transition Minimized Differential Signaling Input can be received. The timing signals Vsync, Hsync, DE and DCLK may include a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE and a dot clock signal DCLK. The timing controller 110 generates timing control signals DDC and GDC for controlling the operation timings of the data driver 120 and the gate driver 130 based on the timing signals Vsync, Hsync, DE, and DCLK from the system board. ).

The data timing control signal DDC includes a source start pulse SSP, a source sampling clock SSC, a source output enable signal SOE, a polarity control signal Polarity, POL), and the like. The source start pulse SSP can control the data sampling start timing of the data driver 120. The source sampling clock SSC is a clock signal for controlling the sampling operation of data in the data driver 120 based on the rising or falling edge. If the signal transmission scheme between the timing controller 110 and the data driver 120 is a mini LVDS interface, the source start pulse SSP and the source sampling clock SSC may be omitted. The polarity control signal POL may invert the polarity of the data voltage output from the data driver 120 in a period of N (N is a positive integer) horizontal period. The source output enable signal SOE can control the output timing of the data driver 120.

The gate timing control signal may include a gate start pulse (GSP), a gate shift clock (GSC), a gate output enable signal (GOE), and the like. The gate start pulse (GSP) can control the timing of the first gate pulse. The gate shift clock GSC is a clock signal for shifting the gate start pulse GSP. The gate output enable signal GOE can control the output timing of the gate driver 130. [

The system board can supply digital video data (RGB) to the timing controller 110. The system board includes a broadcast signal receiving circuit, an external device interface circuit, a graphic processing circuit, and the like, receives video data from a broadcast signal or an image source input from an external device, converts the video data into digital data, and supplies the digital data to the timing controller 110 . The system board can supply the timing controller 110 with timing signals such as a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE, and a dot clock signal DCLK.

The backlight unit 160 may include a plurality of light sources. The backlight unit 160 may be implemented as a direct type backlight unit 160 or an edge type backlight unit 160. [ The direct-type backlight unit 160 has a structure in which a plurality of optical sheets and a diffusion plate are stacked under the display panel 140 and a plurality of light sources are disposed under the diffusion plate. The direct-type backlight unit 160 can implement local dimming by disposing a plurality of light sources under the diffusion plate and separately controlling the plurality of light sources. The edge type backlight unit 160 has a structure in which a light source is disposed so as to face the side face of the light guide plate and a plurality of optical sheets are disposed between the display panel 140 and the light guide plate. The plurality of optical sheets include at least one prism sheet and at least one diffusing sheet to diffuse the light incident from the diffuser plate and to guide the light path of the light at an angle substantially perpendicular to the light incident surface of the display panel 140 Can be refracted. The plurality of optical sheets may include a dual brightness enhancement film (DBEF).

The timing controller 110 can perform an operation on video data so as to increase the sharpness of the image and enhance the immersion feeling by realizing a more realistic image quality by giving a stereoscopic effect to the image. Specifically, the timing controller 110 generates a shadow map using the video data for the original image, computes and applies the shadow gain using the shadow map, and outputs the video data for the original image and the original image The global feedback gain can be computed and applied based on the video data for the global feedback gain.

Referring to FIG. 2, the timing controller 110 includes a shadow map generator 111, a shadow gain calculator 112, and a global feedback gain calculator 113. The shadow map generation unit 111 may generate a shadow map using video data for the original image to be provided to the display panel 140. [ The shadow gain calculator 112 can calculate the shadow gain for the shadow thickness and size in the shadow map, and apply the shadow gain to the video data for the original image. The global feedback gain calculator 113 calculates a global feedback gain based on the video data of the original image and the original image to which the shadow gain is applied and outputs a global feedback gain to the video data of the original image to which the shadow gain is applied Can be applied. In addition, the global feedback gain calculator 113 may calculate the global feedback gain calculator 113 so that the video data for the original image to which the shadow gain and the global feedback gain are applied, that is, the final digital video data R'G'B ' To the data driver 120. 1 and 2, the timing controller 110 includes the shadow map generator 111, the shadow gain calculator 112 and the global feedback gain calculator 113. The shadow map generator 111, The gain computing unit 112 and the global feedback gain computing unit 113 may be included in the display device 100 as an additional component outside the timing controller 110. [ 2, the timing controller 110 includes three configurations, that is, a shadow map generator 111, a shadow gain calculator 112, and a global feedback gain calculator 113. However, the shadow map generator 111 ), The shadow gain computing unit 112, and the global feedback gain computing unit 113 may be integrated into one configuration or may be divided into a plurality of configurations.

Hereinafter, the operation of the timing controller 110 will be described in more detail with reference to FIG.

3 is a flowchart illustrating a method of driving a display device according to an embodiment of the present invention.

First, the shadow map generation unit 111 generates a shadow map using video data of the original image (S10).

The shadow map generating unit 111 of the timing controller 110 generates a shadow map using video data for the original image to be provided to the display panel 140. [ Accordingly, the shadow map generation unit 111 first receives the video data for the original image. The video data for the original image may be video data of the RGB type, or the video data of the RGB type may be video data converted into the YCbCr color space. If the video data of the original image received by the shadow map generation unit 111 is RGB type video data, the shadow map generation unit 111 may convert RGB type video data into a YCbCr color space. Hereinafter, the video data for the original image will be described as being video data for one frame of the original image, for example.

The shadow map generation unit 111 can generate a shadow map by shifting the original image to the right to obtain a right image, and comparing the original image and the right image. Reference is made to FIGS. 4A and 4B together with the shadow map generation unit 111 to compare the original image and the right image to generate a shadow map in more detail.

4A and 4B are images for explaining a process of generating a shadow map. 4A is an original image 410, and FIG. 4B is a right image 420 obtained by shifting the original image 410 to the right.

The shadow map generation unit 111 shifts the original image 410 shown in FIG. 4A to the right to acquire the right image 420 as shown in FIG. 4B. The right image 420 can be obtained by shifting the original image 410 to the right by a predetermined amount of pixel shift. For example, the right image 420 can be obtained by shifting the original image 410 to the right by n pixels, as shown in FIG. 4B.

The amount of pixel movement, which is the degree to which the original image 410 is shifted to the right, may be predetermined and stored in memory. That is, the optimal pixel shift amount for generating the shadow map is calculated in advance and stored in the memory, and the shadow map generation unit 111 shifts the original image 410 to the right by a predetermined amount of pixel shift stored in the memory, (420).

Alternatively, the amount of pixel movement, which is the degree to which the original image 410 is shifted to the right, may be determined based on the depth information of the original image 410. That is, the shadow map generation unit 111 can calculate the optimum pixel shift amount for generating the shadow map for the original image 410 based on the depth information of the original image 410, The right image 420 can be obtained by shifting the right image 410 to the right.

If the amount of pixel movement, which is the degree to which the original image 410 is shifted to the right, is too large, the image processed image may be annoying too much. Also, since the meaning of applying the shadow map is reduced when the pixel shift amount is too small, the user may not feel a stereoscopic effect. Therefore, in the display device 100 and the display device driving method according to the embodiment of the present invention, the optimum pixel shift amount can be calculated by taking both the both sides of the eye and the three-dimensional sense side into account, and for example, Pixel.

Here, for the video data of the original image 410 corresponding to the left hole of the right image 420, the shadow image gain and the global feedback gain are not applied, and the original image 410 may be used as it is. Referring to FIG. 4B, as the original image 410 moves to the right by n pixels to generate the right image 420, a left hole corresponding to n pixels is displayed on the left side of the right image 420 Occurs. Therefore, a luminance value corresponding to the image can not be generated in the portion corresponding to the left hole. Accordingly, the original image 410 can be directly output to the display panel 140 without applying the shadow gain and the global feedback gain to the video data for the original image 410 corresponding to the left hole.

The shadow map generation unit 111 compares the original image 410 and the right image 420 to generate a shadow map. At this time, the shadow map generation unit 111 can generate the shadow map by calculating the difference between the luminance value of the original image 410 and the luminance value of the right image 420 on a pixel-by-pixel basis. That is, the shadow map generation unit 111 may generate the shadow map by subtracting the luminance value of the right image 420 from the luminance value of the original image 410 for each pixel. Accordingly, the shadow map may represent the difference between the luminance value of the original image 410 and the luminance value of the right image 420 for each pixel.

When the original image 410 uses an image shifted to the left in order to generate a shadow map, a problem may arise in which the image-processed image becomes noisy and the three-dimensional effect is not felt. Therefore, in the display device 100 and the display device driving method according to the embodiment of the present invention, the right image 420 in which the original image 410 is shifted to the right is used to generate a shadow map, It is possible to provide an image that can be felt.

Next, the shadow gain calculator 112 calculates a shadow gain for the shadow thickness and size in the shadow map (S20).

The shadow gain computing unit 112 can calculate the data average value for each pixel in the shadow map to calculate the shadow gain. Specifically, the shadow gain calculating unit 112 calculates an average of data values of a target pixel, n pixels on the left side of the target pixel, and n pixels on the right side of the target pixel in order to calculate the data average value of the target pixel in the shadow map can do.

If the target pixel is placed adjacent to both edges of the image and there are no n pixels left and right, then the average of the data values can be computed via the mirroring scheme. For example, when n pixels exist on the left side of the target pixel and n-1 pixels exist on the right side, that is, when the rightmost pixel does not exist on the basis of the target pixel, The value can be replaced with the data value of the leftmost pixel of the target pixel.

The number of pixels used by the shadow gain computing unit 112 to calculate the data average value of the target pixel is determined by the number of pixels to which the shadow map generating unit 111 shifts the original image 410 to the right in order to acquire the right image 420 May be determined based on the number. Specifically, the number of left and right neighboring pixels used for calculating the average value of the shadow gain calculator 112 and the target pixel is calculated from the number of pixels for which the shadow map generator 111 shifts the original image 410 to the right Can be the same. That is, since the shadow map generation unit 111 generates an overlap between the original image 410 and the right image 420 by the number of pixels shifted to the right by the original image 410, Adjacent pixels may be used in calculating the average value of the data of the target pixel. For example, in the case where the shadow map generation unit 111 obtains the right image 420 by shifting the original image 410 to the right by four pixels as described above, the shadow gain calculation unit 112 calculates the target pixel, The average of the data values of the four pixels on the left side of the target pixel and the four pixels on the right side of the target pixel in total can be calculated and used as the data average value of the target pixel.

The shadow gain calculator 112 can determine the shadow gain for the target pixel differently when the data average value of the target pixel has a positive value and when the data average value has a negative value. The average data value of the target pixel means an average value of the difference between the luminance value of the original image 410 and the luminance value of the right image 420 represented by the target pixel and the pixel around the target pixel. Accordingly, when the average value of the data average of the target pixel, that is, the average value of the differences of the brightness values, is greater than 0, the cognitive difference felt by the user is larger as the shadow gain is changed than when the average value of the brightness value differences is smaller than 0. Specifically, when the average value of the data of the target pixel is greater than 0, a predetermined value is added to the luminance value of the original image 410 in the process of applying the shadow gain, and when the data average value of the target pixel is less than 0, A predetermined value is subtracted from the luminance value of the original image 410. In this case, At this time, if the luminance value of the original image 410 is reduced in the process of applying the shadow gain, the user can not easily perceive cognitive artifacts. However, if the luminance value of the original image 410 increases, The brightness of the portions to be displayed in detail can be increased and recognized as white. Accordingly, the corresponding portion may be recognized by the user as an artifact or recognized as a color dropout phenomenon. Therefore, in order to minimize artifacts and color dropout as described above, the shadow gain calculator 112 determines the shadow gain for the target pixel differently when the average value of the data of the target pixel has a positive value and when it has a negative value .

Reference is now made to Figs. 5 and 6 together with a detailed description of a specific process for determining the shadow gain.

5 is a graph for explaining the shadow gain in the display device driving method according to an embodiment of the present invention.

Referring to FIG. 5, the shadow gain is determined on the basis of the data average value calculated for each pixel in the above-described shadow map, and is determined on a basis different from each other based on the interval of the data average value.

5, the shadow gain calculator 112 can determine the shadow gain for the target pixel to be 1 when the data average value of the target pixel is from the first negative value to 0 (③ section in FIG. 5) . That is, when the data average value of the target pixel has a negative value adjacent to 0, the shadow gain for the target pixel can be determined to be 1.

The shadow gain calculator 112 determines that the shadow gain for the target pixel decreases as the average data value of the target pixel increases to a first ratio when the data average value of the target pixel is 0 to the first positive value The shadow gain for the target pixel can be determined. That is, when the data average value of the target pixel is 0, the shadow gain for the target pixel is 1 and the shadow gain for the target pixel is decreased so that the average value of the data of the target pixel increases from 0 to the first positive value, Can be determined.

When the data average value of the target pixel is the second negative value to the first negative value (the second interval in FIG. 5), the shadow gain calculator 112 calculates the shadow gain for the target pixel as the average data value of the target pixel decreases, The shadow gain for the target pixel can be determined. That is, when the average value of the data of the target pixel is the first negative value, the shadow gain for the target pixel is 1, and as the data average value of the target pixel decreases from the first negative value to the second negative value, The shadow gain for the pixel can be determined. At this time, the second ratio may be larger than the first ratio. That is, the absolute value of the slope of the graph of the shadow gain in the section (2) of FIG. 5 may be larger than the absolute value of the slope of the graph of the shadow gain in the section (4) of FIG.

5). When the average value of the data of the target pixel is larger than the first positive value (the ⑤ section in FIG. 5) and the second negative value is smaller than the second negative value (the section ① in FIG. 5), the shadow gain calculating section 112 calculates the shadow gain 0 < / RTI >

As described above, when the average value of the data of the target pixel is larger than 0, there is a large difference in the user's perception that can occur as the shadow gain is changed as compared with the case where the data average value of the target pixel is smaller than zero. Accordingly, as described above, the data average value of the target pixel can be determined differently for each section. In particular, the ratio of the shadow gain change in the interval in which the data average value of the target pixel is the second negative value to the first negative value (the second interval in Fig. 5) is set to a period in which the data average value of the target pixel is 0 to the first positive value The ratio of change of the shadow gain in the step (4) of FIG. 4) is set to be larger than that in the step (4) of FIG.

6 is a graph for explaining the shadow gain in the display device driving method according to another embodiment of the present invention. FIG. 6 is a graph showing an embodiment in which the shadow gain can be calculated in a different manner from the shadow gain calculating method described with reference to FIG.

Referring to FIG. 6, the shadow gain is determined on the basis of the data average value calculated for each pixel in the above-described shadow map, and is determined on a basis different from each other based on the interval of the data average value.

6, the shadow gain calculator 112 determines whether the average value of the data of the target pixel is equal to or greater than a first negative value (i.e., a third interval in FIG. 6) and a first positive value to a second positive value 5) in Fig. 6), the shadow gain for the target pixel can be determined to be 1.

When the data average value of the target pixel is the second negative value to the first negative value (the second interval in FIG. 6), the shadow gain calculator 112 calculates the shadow gain for the target pixel as the average data value of the target pixel decreases, The shadow gain for the target pixel can be determined. That is, when the average value of the data of the target pixel is the first negative value, the shadow gain for the target pixel is 1, and as the data average value of the target pixel decreases from the first negative value to the second negative value, The shadow gain for the pixel can be determined.

The shadow gain calculator 112 determines that the shadow gain for the target pixel is reduced to a second ratio as the data average value of the target pixel decreases as the data average value of the target pixel is 0 to the first positive value The shadow gain for the target pixel can be determined. That is, when the average value of the data of the target pixel is the first positive value, the shadow gain for the target pixel is 1 and the shadow gain is decreased from 1 as the data average value of the target pixel decreases from the first positive value to 0, The shadow gain can be determined.

When the data average value of the target pixel is the second positive value to the third positive value (the sixth interval in FIG. 6), the shadow gain calculator 112 determines that the shadow gain for the target pixel becomes the third ratio The shadow gain for the target pixel can be determined. That is, when the average value of the data of the target pixel is the second positive value, the shadow gain for the target pixel is 1, and as the data average value of the target pixel decreases from the second positive value to the third positive value, The shadow gain for the pixel can be determined.

6). When the average value of the data of the target pixel is smaller than the second negative value (the section? Of FIG. 6) and the third positive value (the section? Of FIG. 6), the shadow gain calculator 112 sets the shadow gain 0 < / RTI >

Noise may be generated in a specific pixel in processing the original image and noise may be amplified and artifacts may be perceived by the user when a high shadow gain is applied to the pixel where noise is generated. On the other hand, the difference between the luminance value of the pixel in the original image 410 where noises are generated and the luminance value of the corresponding pixel in the right image 420, that is, the average value of the data of the target pixel in which noises occur, . Therefore, in the method of driving a display device according to another embodiment of the present invention, the shadow gain can be determined to be a value smaller than 1 when the data average value of the target pixel is 0 to the first positive value (the ④ section in FIG. 6). In particular, as the data average value of the target pixel is closer to 0, a smaller shadow gain is applied, so that noise can be amplified by the shadow gain and the occurrence of artifacts can be minimized. In addition, a first rate, a second rate and a third rate can be defined such that the occurrence of an artifact is minimized.

In some embodiments, the shadow gain calculator 112 may determine how to calculate the shadow gain based on the distribution of the average data values of each pixel in the shadow map. For example, when the ratio of the pixels having the data average value corresponding to 0 to the first positive value among the plurality of pixels in the shadow map is equal to or larger than a predetermined ratio, the shadow gain can be calculated in the manner as shown in FIG. 6 have. That is, when the number of pixels in which noise occurs is equal to or greater than the threshold value, the calculation method of FIG. 6 for reducing the noise can be applied to minimize the occurrence of artifacts due to noise. Alternatively, when the ratio of the pixel having the data average value corresponding to 0 to the first positive value among the plurality of pixels in the shadow map is less than the predetermined ratio, the shadow gain can be calculated in the manner as shown in FIG. That is, when the number of pixels in which noise is generated is less than the threshold value, the occurrence of artifacts due to noise is very small, so that the calculation method of FIG. 5 can be applied.

Next, the shadow gain computing unit 112 applies the shadow gain to the video data for the original image 410 (S30).

The shadow gain calculator 112 may apply the shadow gain applied in the manner described above to the video data for the original image 410. [ Specifically, after computing the shadow gain for the pixel in the shadow map corresponding to the target pixel in the original image 410, the shadow pixel value of the pixel in the shadow map corresponding to the target pixel in the original image 410 The shadow gain may be applied in such a manner that the value obtained by multiplying the shadow gain is added to the luminance value of the video data for the target pixel in the original image 410. [

Then, the global feedback gain calculator 113 calculates a global feedback gain based on the video data for the original image 410 and the video data for the original image 410 to which the shadow gain is applied (S40).

The global feedback gain calculator 113 may calculate the global feedback gain by comparing the luminance values between the pixels of the original image 410 corresponding to each other and the pixels of the original image 410 to which the shadow gain is applied.

Hereinafter, FIGS. 7 and 8 are referred to together to explain a specific process for determining the global feedback gain in more detail.

7 is a graph for explaining a global feedback gain in a method of driving a display device according to an embodiment of the present invention.

In order to calculate the global feedback gain, the global feedback gain calculator 113 first compares the data of the original image 410 with the data of the original image 410 to which the shadow gain is applied. That is, the global feedback gain calculator 113 compares the data of the original image 410 before the shadow gain is applied with the data of the original image 410 to which the shadow gain is applied. The global feedback gain calculator 113 calculates the difference between the luminance values of the pixels of the original image 410 and the pixels of the original image 410 to which the shadow gain corresponding to the pixels of the original image 410 is applied. That is, the pixels of the original image 410 to which the shadow gain corresponding to the corresponding pixel is applied are compared with each other for each pixel of the original image 410, and a difference in luminance value for each pixel is calculated. Then, the global feedback gain calculator 113 calculates the number of pixels whose difference in luminance value is larger than the threshold value. For example, when there are 100 pixels in which the difference between the luminance values is larger than the threshold value, the global feedback gain calculator 113 may calculate 100 as the number of pixels whose difference in luminance value is larger than the threshold value .

The global feedback gain calculator 113 calculates the global feedback gain according to the number of pixels whose difference in luminance value is larger than the threshold value. Specifically, when the number of pixels having a difference in brightness value is larger than the threshold value is relatively small, it can be determined that the variation in the brightness value is small, so that the maximum global feedback gain can be determined, and if the difference in brightness value is larger than the threshold value When the number of pixels is relatively large, it can be determined that the deviation of the luminance value is large, so that the minimum global feedback gain can be determined. For example, as shown in FIG. 7, when the number of pixels whose difference in luminance value is larger than the threshold value is smaller than the first value (the period (1) in FIG. 7), the global feedback gain is determined to be 1, The global feedback gain is determined to be a minimum value smaller than 1 when the number of pixels whose difference is larger than the threshold value is larger than the second value larger than the first value (section 3 & cir &

Also, when the number of pixels whose difference in luminance value is greater than the threshold value is the first value to the second value (the period (2) in FIG. 7), the global feedback gain calculator 113 linearly decreases The global feedback gain can be determined. 7, a smaller global feedback gain can be applied as the number of pixels whose difference in luminance value is larger than the threshold value increases. The global feedback gain for the section < 2 > in FIG. 7 can be determined through Equation (1) below.

[Equation 1]

However, the first value < the number of pixels in which the difference in luminance value is larger than the threshold value <

Where a is the minimum value of the global feedback gain and is greater than zero and less than one.

8 is a graph for explaining a global feedback gain in a display device driving method according to another embodiment of the present invention. FIG. 8 is a graph showing an embodiment in which a global feedback gain can be calculated in a different manner from the global feedback gain calculation method described with reference to FIG.

In order to calculate the global feedback gain, the global feedback gain calculator 113 first compares the data of the original image 410 with the data of the original image 410 to which the shadow gain is applied. The global feedback gain calculator 113 calculates the difference between the luminance values of the pixels of the original image 410 and the pixels of the original image 410 to which the shadow gain corresponding to the pixels of the original image 410 is applied. That is, the pixels of the original image 410 to which the shadow gain corresponding to the corresponding pixel is applied are compared with each other for each pixel of the original image 410, and the luminance value and the shadow gain of the original image 410 for each pixel are applied The difference in luminance value in the original image 410 is calculated. Then, the global feedback gain calculator 113 calculates the sum of the difference between the luminance value and the threshold value of the pixel for the pixel whose difference in luminance value is larger than the threshold value. For example, when there are 100 pixels in which the difference in luminance value among the plurality of pixels is larger than the threshold value, the difference in luminance value for 100 pixels can be summed. Thus, if the difference in luminance values in 100 pixels is all 10, the sum of the differences in luminance values may be 1000.

The global feedback gain calculator 113 calculates a global feedback gain according to the sum of the differences of the luminance values. Specifically, when the sum of the differences of the luminance values is relatively small, it can be determined that the variation of the luminance values is small, so that the maximum global feedback gain can be determined. When the sum of the differences of the luminance values is relatively large, The minimum global feedback gain can be determined since it can be determined that the deviation is large. For example, as shown in FIG. 8, when the sum of the differences of the luminance values is smaller than the first value (the period (1) in FIG. 8), the global feedback gain is determined to be 1, 1), the global feedback gain is determined to be a minimum value smaller than 1. In this case,

The global feedback gain calculator 113 determines the global feedback gain such that the global feedback gain linearly decreases from 1 to the minimum value when the sum of the differences of the luminance values is the first value to the second value . That is, in the period (2) of FIG. 8, a smaller global feedback gain can be applied as the sum of the differences of the luminance values increases. The global feedback gain for the period (2) in FIG. 8 can be determined by Equation (2) below.

 &Quot; (2) &quot;

However, the first value < the sum of the differences of the luminance values < the second value.

Where beta is the minimum value of the global feedback gain and is greater than zero and less than one.

In the method of driving a display device according to another embodiment of the present invention, the global feedback gain is calculated based on the sum of the differences of the luminance values rather than the number of pixels whose difference in luminance value is larger than the threshold, . For example, when there are two pixels whose difference in luminance value among the plurality of pixels is larger than the threshold value, and the difference in luminance value between the two pixels is all 1 (hereinafter referred to as a first case) It is assumed that the difference of the luminance values is 100 (hereinafter, the second case). When the global feedback gain is calculated based on the number of pixels whose difference in luminance value is larger than the threshold value in the above-described situation, the number of pixels whose difference in luminance value is larger than the threshold value in both the first case and the second case is The same global feedback gain is calculated. However, although the difference in the luminance value is larger in the second case than in the first case, the difference in the luminance value is not reflected in the global feedback gain. On the other hand, when the global feedback gain is calculated based on the sum of the differences of the luminance values, the sum of the differences of the luminance values in the first case is 2 while the sum of the differences of the luminance values in the second case is 200, It can be determined that the second case is a case where the change of the luminance value is large in the entire image. Therefore, when the global feedback gain is calculated based on the sum of the differences in the luminance values, the global feedback gain that more accurately matches the actual data can be calculated.

Then, the global feedback gain calculator 113 applies the global feedback gain to the video data of the original image 410 to which the shadow gain is applied (S50).

The global feedback gain calculator 113 applies the calculated global feedback gain to the video data for the original image 410 to which the shadow gain is applied. Specifically, the global feedback gain calculator 113 can apply the global feedback gain calculated for the first frame of the original image 410 to the second frame after the first frame of the original image 410 to which the shadow gain is applied have. For example, if the global feedback gain for the first frame of the original image 410 calculated by the global feedback gain calculator 113 is?, The global feedback gain calculator 113 calculates the global feedback gain for the first frame, The global feedback gain can be applied in such a manner that the luminance value of all the pixels of the pixel is multiplied by a. Here, the luminance value of the pixel of the second frame means the luminance value in a state in which the shadow gain is applied.

The global feedback gain calculator 113 can determine the global feedback gain to be 1 when there is a scene change in the original image 410. [ As described above, the global feedback gain calculated by the global feedback gain calculator 113 is applied to the next frame, not the current frame. However, if there is a transition between the frame and the next frame, the global feedback gain determined based on the previous frame can not be applied to the next frame. Accordingly, the global feedback gain calculator 113 may determine that the global feedback gain is 1 when there is a scene change, and the global feedback gain may be prevented from being applied incorrectly according to the scene change.

The global feedback gain computing unit 113 computes and applies a global feedback gain for the original image 410 in the process described above to minimize cognitive artifacts that the user can feel even if the data difference is not large during the shadow map use can do.

Next, the timing controller 110 outputs the video data for the original image 410 to which the shadow gain and the global feedback gain are applied (S60).

The timing controller 110 outputs the video data for the original image 410 to which the shadow gain and the global feedback gain are applied to the display panel 140 to the data driver 120. Since the video data for the original image 410 to which the shadow gain and the global feedback gain are applied is video data that has been converted to the YCbCr color space, the timing controller 110 generates the video data for the original image 410 to which the shadow gain and global feedback gain are applied, Data can be converted into RGB type video data and output to the data driver 120. [

In the method of driving a display device according to an exemplary embodiment of the present invention, a shadow gain using a shadow map is applied to give a more improved stereoscopic effect to a two-dimensional image and a more realistic image quality to a user, Apply global feedback gain. Specifically, the shadow gain is calculated based on the thickness and the size of the shadow calculated through the shadow map, and the shadow gain can be applied to the video data of the original image to improve the three-dimensional feeling that the user can feel. However, artifacts can occur in the process of improving the sharpness of the image by applying the shadow gain. Therefore, the global feedback gain that minimizes the artifacts for the entire image is applied to the video data of the original image to which the shadow gain is applied, thereby minimizing the side effects and artifacts such as clipping and noise, and providing a sharp and stereoscopic image This is possible.

9 is a block diagram illustrating a display device according to another embodiment of the present invention. 10 is a flowchart illustrating a method of driving a display device according to another embodiment of the present invention. The display device 900 shown in Fig. 9 differs from the display device 100 shown in Figs. 1 and 2 only in that the configuration of the timing controller 910 is changed. Therefore, redundant explanations of the same components are omitted do.

9, the timing controller 910 includes a shadow map generator 111, a shadow gain calculator 112, a global feedback gain calculator 913, and a depth gain calculator 914. The shadow map generating unit 111 and the shadow gain calculating unit 112 shown in FIG. 9 are substantially the same as the shadow map generating unit 111 and the shadow gain calculating unit 112 shown in FIG.

10, the shadow map generator 111 generates a shadow map using the video data for the original image 410 (S10), and the shadow gain calculator 112 calculates the shadow thickness and the size of the shadow map in the shadow map The global gain calculator 913 calculates the shadow gain for the original image 410 by applying the shadow gain to the video data for the original image 410 at step S30, The global feedback gain is calculated on the basis of the video data of the original image 410 to which the present invention is applied (S40). Steps S10, S20, S30 and S40 are substantially the same as S10, S20, S30 and S40 described with reference to Fig.

The depth gain calculator 914 calculates the depth gain based on the depth information about the original image 410 (S70).

First, the depth gain calculator 914 acquires depth information about the original image 410. The depth gain calculator 914 may obtain depth information about the original image 410 from outside the timing controller 910 and may acquire depth information by other elements in the timing controller 910. [ Alternatively, the depth gain calculator 914 may directly obtain the depth information based on the video data of the original image 410. Here, the depth information for the original image 410 means information indicating the depth value of the object on the original image 410.

The depth gain calculator 914 calculates a depth gain for the original image 410 based on the depth information. The depth gain can be calculated proportional to the depth in the target pixel of the original image 410. [ Specifically, the depth gain calculator 914 can calculate the depth gain so that the depth gain becomes larger as the pixel has a larger depth. That is, as the depth of the target pixel becomes deeper, the depth gain is set to be larger, and the three-dimensional effect and clarity can be improved.

Next, the depth gain calculator 914 applies a depth gain to the video data of the original image 410 to which the shadow gain is applied, before applying the global feedback gain to the data of the original image 410 to which the shadow gain is applied (S80).

After the shadow gain computing unit 112 applies the shadow gain to the video data of the original image 410 as described above, the depth gain computing unit 914 adds the depth gain to the video data of the original image 410 to which the shadow gain is applied Can be applied. The depth gain calculator 914 can apply the depth gain by multiplying the luminance value of each pixel in the original image 410 to which the shadow gain is applied by the depth gain.

Next, the global feedback gain calculator 913 can apply the global feedback gain to the video data of the original image 410 to which the shadow gain and the depth gain are applied (S50 '). The global feedback gain calculator 913 calculates the global feedback gain calculated for the first frame of the original image 410 in the second frame after the first frame of the original image 410 to which the shadow gain and the depth gain are applied Can be applied. For example, if the global feedback gain for the first frame of the original image 410 calculated by the global feedback gain calculator 913 is?, The global feedback gain calculator 913 calculates the global feedback gain for the first frame, The global feedback gain can be applied in such a manner that the luminance value of all the pixels of the pixel is multiplied by a. Here, the luminance value of the pixel of the second frame means the luminance value in a state in which the shadow gain and the depth gain are applied. The global feedback gain calculator 913 and the step S50 'refer to FIGS. 2 and 3, except that the data to which the global feedback gain operation is applied is video data for the original image 410 to which the shadow gain and the depth gain are applied Is substantially the same as the global feedback gain calculator 913 and step S50 described above.

Next, the timing controller 910 outputs video data for the original image 410 to which the shadow gain, the depth gain, and the global feedback gain are applied (S60 '). Step 60 'is substantially the same as step S60' described with reference to FIG. 3, except that a depth gain is additionally applied to the data output by the timing controller 910.

In the display device 900 and the display device driving method according to another embodiment of the present invention, not only the shadow gain and the global feedback gain but also the depth gain calculated based on the depth information is also applied to the video data for the original image 410. [ That is, by using the depth gain determined using the depth information indicating the depth of the object in the original image 410, an image having more stereoscopic and clear image quality can be provided to the user.

11 is a block diagram for explaining a display device according to another embodiment of the present invention. 11, the display device 1100 includes a timing controller 1110, a gate driver 1130, a data driver 1120, and a display panel 1140. The display panel 1140 is an organic light emitting display panel 1140 and the display device 1100 is an organic light emitting display 1100 including an organic light emitting display panel 1140. [

The display panel 1140 is formed so that a plurality of data lines DL and a plurality of gate lines GL cross each other. A pixel array in which a plurality of pixels are arranged in a matrix form is arranged in an intersection area of a plurality of data lines DL and a plurality of gate lines GL. Each of the plurality of pixels of the display panel 1140 may include one or more switching thin film transistors, a driving thin film transistor, an organic light emitting element, and one or more capacitors. Each of the plurality of pixels can display an image by controlling a current flowing through the organic light emitting element using a switching thin film transistor and a driving thin film transistor. The display panel 1140 may display an image in the form of bottom emission and top emission depending on the pixel structure.

The gate driver 1130 may include a plurality of gate driver ICs. The gate drive IC controls switching thin film transistors of each of a plurality of pixels using one or more gate pulses. The gate drive IC sequentially supplies the gate pulses to the plurality of gate lines GL of the display panel 1140. The gate drive IC may be mounted on a gate TCP (tape carrier package), and the gate TCP may be bonded to the display panel 1140 by a TAB (tape automated bonding) process. Alternatively, the gate drive IC may be directly formed simultaneously with the pixel array by a GIP (gate in panel) process.

The data driver 1120 may include a plurality of source driver ICs. The source drive IC receives the digital video data (DATA) from the timing controller 1110. The source driver IC may receive the gamma reference voltage from the gamma reference voltage output section and may calculate the gamma compensation voltage from the gamma reference voltage using a voltage divider circuit. The source driver IC converts the digital video data DATA into an analog data voltage using the gamma compensation voltage and supplies the data voltage to the plurality of data lines DL of the display panel 1140 in synchronization with the gate pulse . The source driver IC may be mounted on the source TCP, and the source TCP may be bonded to the display panel 1140 and the source PCB (printed circuit board) by a TAB process. Alternatively, the source drive ICs may be directly bonded to the display panel 1140 by a COG (chip on glass) process.

The timing controller 1110 may control the data driver 1120 and the gate driver 1130. The timing controller 1110 can receive digital video data (DATA) and timing signals (Vsync, Hsync, DE, DCLK). The timing signals Vsync, Hsync, DE and DCLK may include a vertical synchronization signal Vsync, a horizontal synchronization signal Hsync, a data enable signal DE and a dot clock signal DCLK. The timing controller 1110 receives a gate timing control signal GCS for controlling the operation timing of the gate driving unit 1130 and a timing control signal GCS for controlling the operation timing of the data driving unit 1120 based on the timing signals (Vsync, Hsync, DE, DCLK) And generate a data timing control signal (DCS) for controlling the operation timing. The timing controller 1110 outputs the gate timing control signal GCS to the gate driver 1130 and the digital video data DATA and the data timing control signal DCS to the data driver 1120.

The timing controller 1110 can perform an operation on video data so as to increase the sharpness of the image and enhance the immersion feeling by giving a stereoscopic effect to the image to realize a more realistic image quality. Specifically, the timing controller 1110 uses the video data for the original image to generate a shadow map using the video data for the original image, computes and applies the shadow gain, and provides the video data for the original image and the shadow gain The global feedback gain can be computed and applied based on the video data for the applied original image. The timing controller 1110 can also apply the depth gain calculated based on the depth information to the video data for the original image. The functions of the timing controller 110 described with reference to FIGS. 1 to 10 can be applied to the timing controller 1110 except that the timing controller 1110 is applied to the organic light emitting display 1100. [ Accordingly, even when the display device 1100 is the organic light emitting display device 1100, it is possible to provide a more improved stereoscopic effect to the two-dimensional image and to realize a more realistic image quality to the user.

The display device and the display device driving method according to the embodiments of the present invention can be described as follows.

A method of driving a display device includes generating a shadow map using video data for an original image, computing a shadow gain for the shadow thickness and size in the shadow map, applying a shadow gain to the video data for the original image Calculating a global feedback gain based on video data for the original image before the shadow gain is applied and the original image for which the shadow gain is applied, and calculating a global feedback gain for the video data for the original image to which the shadow gain is applied, The method comprising:

According to another aspect of the present invention, the step of generating a shadow map includes the steps of acquiring a right image by shifting the original image to the right, and generating a shadow map by comparing the original image and the right image can do.

According to another aspect of the present invention, the step of generating the shadow map by comparing the original image and the right image includes a step of generating the shadow map by calculating the difference between the luminance value of the original image and the luminance value of the right image, can do.

According to another aspect of the present invention, computing the shadow gain comprises calculating a data average value for each pixel in the shadow map, wherein computing the data average value for each pixel in the shadow map comprises: Calculating an average of data values of a target pixel in the map, n pixels on the left side of the target pixel, and n pixels on the right side of the target pixel as the data average value of the target pixel.

According to another aspect of the present invention, the step of calculating the shadow gain includes determining a shadow gain for a target pixel differently when the average value of the data of the target pixel has a positive value and when the average value has a negative value Step &lt; / RTI &gt;

According to another aspect of the present invention, the step of calculating the shadow gain includes the steps of: determining a shadow gain for a target pixel to be 1 when a data average value of a target pixel is a first negative value to 0; Determining a shadow gain for a target pixel such that a shadow gain for a target pixel decreases to a first ratio as the average data value of the target pixel increases from zero to a first positive value, Determining a shadow gain for a target pixel such that a shadow gain for a target pixel decreases to a second ratio greater than a first rate as the average data value of the target pixel decreases from a negative value to a first negative value, When the data average value is larger than the first positive value and smaller than the second negative value, the shadow map for the target pixel And &quot; 0 &quot; to &quot; 0 &quot;.

According to another aspect of the present invention, the step of calculating the shadow gain includes: when the average value of data of the target pixel is a second negative value to a first negative value, the shadow gain for the target pixel decreases as the data average value of the target pixel decreases Determining a shadow gain for a target pixel so as to decrease to a first ratio, if the data average value of the target pixel is a first negative value to 0 and a first positive value to a second positive value, To 1, and when the average value of the data of the target pixel is 0 to the first positive value, the shadow gain for the target pixel is reduced so that the shadow gain for the target pixel is decreased to the second ratio as the data average value of the target pixel is decreased When the data average value of the target pixel is a second positive value to a third positive value, Determining a shadow gain for a target pixel such that a shadow gain for a target pixel decreases to a third ratio as the average value of the target pixel is increased; and when the average value of data of the target pixel is smaller than a second negative value and larger than a third positive value , And determining the shadow gain for the target pixel to be zero.

According to still another aspect of the present invention, the step of calculating the global feedback gain is a step of calculating a global feedback gain of a pixel having a difference in luminance value between a pixel of the original image and a pixel of the original image to which a shadow gain corresponding to the pixel of the original image is applied, Determining a global feedback gain to be 1 if the number is less than a first value, and determining a global feedback gain to be a minimum value less than 1 if the number is greater than a second value greater than the first value, And if the number is a first value to a second value, determining that the global feedback gain linearly decreases from 1 to a minimum value, wherein applying the global feedback gain comprises: applying a global feedback gain to the next frame of the calculated frame And applying a global feedback gain to the video data for the original image of the source image.

According to another aspect of the present invention, the step of calculating the global feedback gain includes: calculating a global feedback gain based on a difference between luminance values of pixels of an original image and pixels of an original image to which a shadow gain corresponding to a pixel of the original image is applied, Determining a global feedback gain to be 1 if the sum of the differences is less than the first value; and if the sum of the differences is greater than a second value greater than the first value, setting the global feedback gain to 1 Determining a global feedback gain to linearly decrease from 1 to a minimum value if the sum of the differences is a first value to a second value, Applying a global feedback gain to the video data for the original image of the next frame of the frame in which the feedback gain is calculated .

According to another aspect of the present invention, a method of driving a display device includes the steps of acquiring depth information on an original image, calculating a depth gain on the original image based on the depth information, and applying a global feedback gain And applying a depth gain to the video data for the original image to which the shadow gain is applied, wherein applying the global feedback gain comprises applying a global feedback gain to the video data for the original image to which the shadow gain and the depth gain are applied And the like.

According to another aspect of the present invention, the step of calculating the depth gain may include calculating a depth gain of the target pixel in proportion to the depth of the target pixel of the original image.

The display device includes a shadow map generator for generating a shadow map using video data for the original image to be provided on the display panel and the display panel, a shadow gain generator for calculating a shadow gain for the shadow thickness and size in the shadow map, A shadow gain operation unit for applying the shadow gain to the video data for the image, and a global feedback gain based on the video data for the original image to which the shadow gain is applied and the video data for the original image before the shadow gain is applied, And a global feedback gain operation unit for applying global feedback gain to video data for the image and providing video data for the original image to which the shadow gain and global feedback gain are applied, to the display panel.

According to another aspect of the present invention, the shadow map generation unit may generate a shadow map by obtaining a right image by shifting the original image to the right and comparing the original image and the right image.

According to another aspect of the present invention, the global feedback gain computing unit may provide video data for the original image corresponding to the left hole of the right image to the display panel without applying the shadow gain and the global feedback gain.

According to still another aspect of the present invention, the shadow gain computing unit calculates an average of data values of a target pixel in the shadow map, n pixels on the left side of the target pixel, and n pixels on the right side of the target pixel, , And the number of pixels for which the shadow map generator shifts the original image to the right may be n.

According to another aspect of the present invention, the shadow gain computing unit may determine a shadow gain for a target pixel differently when the average value of data of the target pixel has a positive value and when the average value has a negative value.

According to another aspect of the present invention, the shadow gain computing unit can determine a method of computing the shadow gain based on the distribution of the average value of data of each pixel in the shadow map.

According to another aspect of the present invention, the global feedback gain computing unit may calculate the global feedback gain based on the number of pixels whose difference in luminance value between the pixels of the original image and the pixels of the original image to which the shadow gain is applied corresponding to the pixels of the original image, The global feedback gain is determined to be 1 when the number is smaller than the first value and the global feedback gain is determined to be the minimum value smaller than 1 when the number is larger than the second value which is larger than the first value, Value to a second value, the global feedback gain may be determined to linearly decrease from 1 to the minimum value, and a global feedback gain may be applied to the video data for the original image of the next frame of the frame in which the global feedback gain is calculated.

According to another aspect of the present invention, the global feedback gain computing unit may calculate a global feedback gain based on a difference between a luminance value between pixels of an original image and pixels of an original image to which a shadow gain corresponding to a pixel of the original image is applied, And if the sum of the differences is smaller than the first value, the global feedback gain is determined as 1. If the sum of the differences is larger than the second value larger than the first value, the global feedback gain is set to a minimum value smaller than 1 And determines that the global feedback gain linearly decreases from 1 to the minimum value if the sum of the differences is from the first value to the second value and determines that the global feedback gain is less than or equal to the minimum value in the video data for the original image of the next frame of the calculated frame Global feedback gain can be applied.

According to another aspect of the present invention, a display device obtains depth information about an original image, calculates a depth gain for the original image based on the depth information, and calculates a global feedback gain based on the data on the original image to which the shadow gain is applied Further comprising a depth gain calculator for applying a depth gain to the video data of the original image to which the shadow gain is applied, wherein the global feedback gain calculator calculates the global gain of the video data for the original image to which the shadow gain and the depth gain are applied, Global feedback gain can be applied.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, it is to be understood that the present invention is not limited to those embodiments and various changes and modifications may be made without departing from the scope of the present invention. . Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (20)

Generating a shadow map using video data for the original image;
Computing a shadow gain for the shadow thickness and size in the shadow map;
Applying the shadow gain to video data for the original image;
Computing a global feedback gain based on video data for the original image before applying the shadow gain and video data for the original image to which the shadow gain is applied; And
And applying the global feedback gain to video data for the original image to which the shadow gain is applied. The method according to claim 1,
Wherein the generating the shadow map comprises:
Obtaining a right image by shifting the original image to the right; And
And comparing the original image with the right image to generate the shadow map. 3. The method of claim 2,
Wherein the generating the shadow map by comparing the original image with the right image comprises generating the shadow map by computing the difference between the luminance value of the original image and the luminance value of the right image pixel by pixel, Device driving method. The method according to claim 1,
Wherein computing the shadow gain comprises computing a data mean for each pixel in the shadow map,
Wherein the step of calculating the data average value for each pixel in the shadow map comprises calculating an average of data values of a target pixel in the shadow map, n pixels on the left side of the target pixel, and n pixels on the right side of the target pixel, And calculating an average value of the data of the target pixel. 5. The method of claim 4,
Wherein computing the shadow gain comprises determining a shadow gain for the target pixel differently when the average value of the data of the target pixel has a positive value and when it has a negative value. Device driving method. 6. The method of claim 5,
Wherein the step of calculating the shadow gain comprises:
Determining a shadow gain for the target pixel to be 1 if the data average value of the target pixel is a first negative value to 0;
Determining a shadow gain for the target pixel so that the shadow gain for the target pixel decreases to a first ratio as the average data value of the target pixel increases from 0 to the first positive value, ;
Wherein when the data average value of the target pixel is a second negative value to a first negative value, the shadow gain for the target pixel is reduced to a second ratio larger than the first ratio as the data average value of the target pixel decreases, Determining a shadow gain for a target pixel; And
Determining a shadow gain for the target pixel to be 0 when the data average value of the target pixel is larger than the first positive value and smaller than the second negative value. 6. The method of claim 5,
Wherein the step of calculating the shadow gain comprises:
Wherein when the data average value of the target pixel is from the second negative value to the first negative value, the shadow gain for the target pixel is decreased so that the shadow gain for the target pixel decreases as the data average value of the target pixel decreases, ;
Determining a shadow gain for the target pixel to be 1 if the data average value of the target pixel is the first negative value to 0 and the first positive value to the second positive value;
And determines a shadow gain for the target pixel so that the shadow gain for the target pixel decreases to a second ratio as the average data value of the target pixel decreases as the data average value of the target pixel is 0 to the first positive value step;
Wherein when the average value of the data of the target pixel is the second positive value to the third positive value, the shadow gain for the target pixel is reduced to a third ratio as the data average value of the target pixel increases, ; And
Determining a shadow gain for the target pixel to be 0 when the data average value of the target pixel is smaller than the second negative value and larger than the third positive value. The method according to claim 1,
Wherein the step of computing the global feedback gain comprises:
Calculating a number of pixels having a difference in luminance value between a pixel of the original image and a pixel of the original image to which the shadow gain is applied corresponding to the pixel of the original image is greater than a threshold value;
Determining the global feedback gain to be 1 if the number is less than a first value;
Determining the global feedback gain as a minimum value less than 1 if the number is greater than a second value greater than the first value; And
Determining that the global feedback gain linearly decreases from 1 to the minimum value if the number is the first value to the second value,
Wherein applying the global feedback gain comprises applying the global feedback gain to video data for the original image of the next frame of the frame in which the global feedback gain is calculated. The method according to claim 1,
Wherein the step of computing the global feedback gain comprises:
Calculating a sum of the differences for pixels having a difference in luminance value between a pixel of the original image and a pixel of the original image to which the shadow gain is applied corresponding to the pixel of the original image is larger than a threshold value;
Determining the global feedback gain to be 1 if the sum of the differences is less than a first value;
Determining the global feedback gain as a minimum value less than 1 if the sum of the differences is greater than a second value greater than the first value; And
Determining that the global feedback gain linearly decreases from 1 to the minimum value if the sum of the differences is the first value to the second value,
Wherein applying the global feedback gain comprises applying the global feedback gain to video data for the original image of the next frame of the frame in which the global feedback gain is calculated. The method according to claim 1,
Obtaining depth information on the original image;
Calculating a depth gain for the original image based on the depth information; And
Further comprising applying the depth gain to video data for the original image to which the shadow gain is applied, prior to applying the global feedback gain,
Wherein applying the global feedback gain comprises applying the global feedback gain to video data for the original image to which the shadow gain and the depth gain are applied. 11. The method of claim 10,
Wherein the step of calculating the depth gain includes calculating a depth gain of the target pixel in proportion to the depth of the target pixel of the original image. Display panel;
A shadow map generator for generating a shadow map using video data of an original image to be provided on the display panel;
A shadow gain calculator for calculating a shadow gain for the shadow thickness and size in the shadow map and applying the shadow gain to video data for the original image; And
Calculating a global feedback gain based on the video data for the original image before the shadow gain is applied and the video data for the original image to which the shadow gain is applied, And a global feedback gain computing unit for applying feedback gain and providing the display panel with video data on the original image to which the shadow gain and the global feedback gain are applied. 13. The method of claim 12,
Wherein the shadow map generator obtains a right image by shifting the original image to the right and compares the original image with the right image to generate the shadow map. 14. The method of claim 13,
Wherein the global feedback gain computing section provides the display panel with video data for the original image corresponding to the left hole of the right image without applying the shadow gain and the global feedback gain. 14. The method of claim 13,
Wherein the shadow gain computing unit computes an average of data values of a target pixel in the shadow map, n pixels on the left side of the target pixel, and n pixels on the right side of the target pixel as the data average value of the target pixel,
Wherein the shadow map generator shifts the original image to the right by n pixels. 16. The method of claim 15,
Wherein the shadow gain computing unit determines a shadow gain for the target pixel differently when the data average value of the target pixel has a positive value and when the data average value has a negative value. 14. The method of claim 13,
Wherein the shadow gain computing unit determines a method of calculating the shadow gain based on a distribution of an average value of data of each pixel in the shadow map. 13. The method of claim 12,
The global feedback gain computing unit may include:
Calculating a number of pixels having a difference in luminance value between a pixel of the original image and a pixel of the original image to which the shadow gain is applied corresponding to the pixel of the original image,
Determines the global feedback gain to be 1 if the number is less than a first value,
Determining the global feedback gain to be a minimum value less than 1 if the number is greater than a second value greater than the first value,
Determining that the global feedback gain linearly decreases from 1 to the minimum value when the number is the first value to the second value,
Wherein the global feedback gain is applied to the video data for the original image of the next frame of the frame for which the global feedback gain is calculated. 13. The method of claim 12,
The global feedback gain computing unit may include:
Calculating a sum of the differences for pixels having a difference in luminance value between a pixel of the original image and a pixel of the original image to which the shadow gain is applied corresponding to the pixel of the original image,
Determining the global feedback gain to be 1 if the sum of the differences is less than the first value,
Determining the global feedback gain to be a minimum value less than 1 if the sum of the differences is greater than a second value greater than the first value,
Determining that the global feedback gain linearly decreases from 1 to the minimum value if the sum of the differences is the first value to the second value,
Wherein the global feedback gain is applied to the video data for the original image of the next frame of the frame for which the global feedback gain is calculated. 13. The method of claim 12,
The depth gain for the original image is calculated on the basis of the depth information and the global feedback gain is applied to the data for the original image to which the shadow gain is applied, Further comprising a depth gain operation unit for applying the depth gain to the video data of the original image to which the shadow gain is applied,
Wherein the global feedback gain operation unit applies the global feedback gain to video data for an original image to which the shadow gain and the depth gain are applied.

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