KR20170037783A - Method for logo detection and display device using thereof - Google Patents

Abstract

The present invention can improve the lifespan of an afterimage and increase the lifespan of a display panel by detecting a still logo including a translucent logo and changing the brightness without the deterioration of image quality. To this end, the present invention divides an image into blocks, calculates a difference value between a prior block and a posterior block, classifies a logo candidate group block and a non-logo block based on the difference value, classifies a logo candidate group by block, expands the log candidate group, groups the identical logo candidate groups, discriminates a logo and a non-logo within the expanded logo candidate group based on an adaptive threshold value, and compensates for the detected logo.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of detecting a logo,

The present invention relates to a logo detection method and a display device using the same.

As the information technology is developed, the market of display devices, which is a connection medium between users and information, is getting larger. Accordingly, the organic light emitting diode (OLED), the quantum dot display (QDD), the liquid crystal display (LCD), the plasma display panel (PDP) The use of the same display device is increasing.

The display device includes a display panel including a plurality of sub-pixels arranged in a matrix form, a driver for outputting a drive signal for driving the display panel, and a controller for controlling the driver.

The display device is implemented as a television, a set-top box, a navigation device, a video player, a Blu-ray player, a personal computer (PC), a home theater and a mobile phone. The images used on television include a variety of logos such as opaque logos, translucent logos or animated logos.

In some of the display devices, the brightness characteristics change due to deterioration of the device. Therefore, when an image including an opaque logo or a translucent logo on the display panel is displayed over a long period of time, deterioration of the logo portion appears prominently. In such a case, a residual image may be generated on the display panel due to the difference in degree of deterioration between the region deteriorated by the logo and the peripheral region, and the display quality and the life may be lowered.

The present invention for solving the problems of the background art detects a still logo including a translucent logo and changes the brightness without degrading the image quality thereof to improve the life of the display panel and to improve the afterglow life and to improve the artifact ) To improve and improve the display quality. In addition, the present invention improves the memory increase (or shortage) problem by dynamically allocating memory of a predetermined size for pixel-by-pixel compensation after deriving a logo candidate group.

The present invention provides a display device including a difference value calculating unit, a logo candidate group estimating unit, a logo candidate group expanding and grouping unit, an adaptive threshold value setting unit, and a data compensating unit. The difference value calculator divides the image into blocks and calculates difference values between the before and after blocks. The logo candidate group estimator divides the logo candidate block and the non-logo block based on the difference value between the before and after blocks, and classifies the logo candidate group on a block-by-block basis. The logo candidate group expansion and grouping unit expands the logo candidate group and groups the same logo candidates together. The adaptive threshold setting unit obtains adaptive thresholding, and distinguishes the logo from the non-logo in the expanded candidate of the logo based on the adaptive threshold value. The data compensation unit performs compensation for the detected logo.

The adaptive threshold value setting unit may obtain an adaptive threshold value by using an average of difference values between the pixels before and after the pixels in the block classified as the same logo candidate group.

The adaptive threshold value may vary at least every N (N is an integer of 1 or more) frames.

The logo candidate group expansion and grouping unit can extend the logo candidate group up to K (K is an integer of 1 or more) blocks adjacent to the logo candidate group, and group the same logo candidate groups.

And a memory allocation unit for dynamically allocating the logo memory so that the blocks classified as the logo candidate group are allocated to the logo memory and the blocks excluded from the logo candidate group are deleted from the logo memory.

The data compensation unit can compensate the brightness of the detected logo in units of pixels, blocks or pixels and blocks.

In another aspect, the present invention provides a method of detecting a logo. A method of detecting a logo comprises dividing an image into blocks, calculating difference values between the before and after blocks, classifying the logo candidate block and the non-logo block based on the difference between the before and after blocks, Expanding a logo candidate group and grouping the same logo candidates among groups; obtaining an adaptive thresholding; distinguishing a logo and a non-logo in the expanded logo candidate group based on the adaptive threshold value; And performing a compensation for the input signal.

In the step of classifying the logo candidates in units of blocks, the block counter is updated using the difference value between the before and after blocks, and the logo candidate block and the non-logo block can be distinguished by using the block counter.

In the step of distinguishing the logo from the non-logo in the extended logo candidate group, the adaptive threshold value can be obtained by using an average of the difference values between the pixels before and after the pixels in the block classified as the same logo candidate group.

In the step of grouping the same logo candidates, it is possible to expand the logo candidates to K (K is an integer of 1 or more) blocks adjacent to the logo candidate group, and group the same logo candidates together.

The present invention has the effect of detecting a still logo including a translucent logo and varying the brightness without deteriorating image quality, thereby prolonging the life of the display panel and improving the life span of the afterimage. Further, the present invention has the effect of improving and improving the display quality by lowering the influence of the artifacts generated when compensating the detected logos in block units by assigning compensation values in pixel units. The present invention has the effect of classifying a change in motion between frames into an adaptive threshold and detecting and compensating for a translucent logo based on the change. In addition, the present invention has the effect of improving the memory increase (or shortage) problem by dynamically allocating memory of a predetermined size for pixel-by-pixel compensation after deriving a logo candidate group.

1 is a block diagram schematically showing a display device;
Fig. 2 is a schematic view showing the subpixel shown in Fig. 1. Fig.
3 is a schematic diagram for explaining a logo detection method according to an experimental example;
4 is a diagram showing a result of opaque logo detection according to an experimental example;
5 is a diagram showing a result of semitransparent logo detection according to an experimental example.
6 to 8 are views for explaining a logo detection method according to an embodiment of the present invention.
9 is a diagram for explaining a logo estimation process;
10 is a diagram for explaining a logo grouping process;
11 is a diagram for explaining a memory dynamic allocation and storage process;
Fig. 12 is a diagram showing results of detection of an opaque logo and a translucent logo; Fig.
13 and 14 are diagrams for explaining a block counter update process.
15 is a view showing an example of pixel-by-pixel compensation.
Figures 16 and 17 are diagrams showing the difference map of opaque and translucent logos.
Figures 18 and 19 illustrate pixel and block-based compensation examples.
20 is a block diagram schematically showing a part of a display device according to an embodiment of the present invention;
FIG. 21 is a block diagram of the timing control unit shown in FIG. 20; FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The display device using the text detection method according to the present invention is implemented as a television, a set-top box, a navigation device, a video player, a Blu-ray player, a personal computer (PC), a home theater and a mobile phone. The display panel of the display device may be selected from a liquid crystal display panel, an organic light emitting display panel, a quantum dot display device, an electrophoretic display panel, a plasma display panel, and the like, but is not limited thereto.

Fig. 1 is a block diagram schematically showing a display device, and Fig. 2 is a schematic diagram showing a subpixel shown in Fig.

1, the display device includes an image supply unit 110, a timing control unit 120, a gate driving unit 130, a data driving unit 140, and a display panel 150.

The image supply unit 110 processes the data signal and outputs the image signal together with a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, and a clock signal. The image supply unit 110 supplies a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, a clock signal, and a data signal to the timing controller 120 (LVDS) through an LVDS (Low Voltage Differential Signaling) interface or a TMDS (Transition Minimized Differential Signaling) . For example, the image supply unit 110 outputs R, G, and B data signals.

The timing controller 120 receives the data signal DATA from the image supplier 110 and receives the gate timing control signal GDC for controlling the operation timing of the gate driver 130 and the operation timing of the data driver 140 And outputs a data timing control signal (DDC) The timing controller 120 outputs a data signal DATA along with a gate timing control signal GDC and a data timing control signal DDC through a communication interface and controls the operation timing of the gate driver 130 and the data driver 140 .

The gate driver 130 outputs a gate signal (or a scan signal) while shifting the level of the gate voltage in response to the gate timing control signal GDC supplied from the timing controller 120. The gate driver 130 supplies gate signals to the sub-pixels SP included in the display panel 150 through the gate lines GL1 to GLm. The gate driver 130 is formed in the form of an integrated circuit (IC) or a gate in panel (GIP) method in the display panel 150.

The data driver 140 samples and latches the data signal DATA in response to the data timing control signal DDC supplied from the timing controller 120 and converts the digital signal into an analog signal corresponding to the gamma reference voltage and outputs the analog signal . The data driver 140 supplies the data signal DATA to the sub-pixels SP included in the display panel 150 through the data lines DL1 to DLn. The data driver 140 is formed in the form of an integrated circuit (IC).

The display panel 150 displays an image corresponding to the gate signal supplied from the gate driver 130 and the data signal DATA supplied from the data driver 140. The display panel 150 includes a lower substrate, an upper substrate, and subpixels SP formed between the lower substrate and the upper substrate.

As shown in FIG. 2, one sub-pixel is supplied with a switching thin film transistor SW and a switching thin film transistor SW which are connected (or formed at intersections) to the gate line GL1 and the data line DL1 And a pixel circuit PC that operates in response to the data signal DATA. The subpixels SP include a liquid crystal element, an organic light emitting element, and the like depending on the configuration of the pixel circuit PC.

When the display panel 150 is composed of a liquid crystal display panel, it may be a twisted nematic (TN) mode, a VA (Vertical Alignment) mode, an IPS (In Plane Switching) mode, a FFS (Fringe Field Switching) mode, or an ECB (Electrically Controlled Birefringence) Mode. When the display panel 150 is formed of an organic light emitting display panel, the display panel 150 may be implemented as a top emission type, a bottom emission type, or a dual emission type.

The display device displays a specific image as the display panel 150 emits or transmits light based on the gate signal and the data signal DATA output from the gate driver 130 and the data driver 140 .

The display device is implemented as a television, a set-top box, a navigation device, a video player, a Blu-ray player, a personal computer (PC), a home theater and a mobile phone. The images used on television include a variety of logos such as opaque logos, translucent logos or animated logos.

In some of the display devices, the brightness characteristics change due to deterioration of the device. Therefore, when an image including an opaque logo or a translucent logo on the display panel is displayed over a long period of time, deterioration of the logo portion appears prominently. In such a case, a residual image may be generated on the display panel due to the difference in degree of deterioration between the region deteriorated by the logo and the peripheral region, and the display quality and the life may be lowered.

Hereinafter, embodiments of the present invention will be described.

[Experimental Example]

FIG. 3 is a view for schematically explaining a method of detecting a logo according to an experimental example, FIG. 4 is a diagram showing a result of opaque logo detection according to an experimental example, and FIG. 5 is a diagram showing a result of translucent logo detection according to an experimental example .

As shown in FIG. 3, the experimental example detects the logos in the order of the frame comparing step S10, the logo block detecting step S20 and the brightness adjusting step S30, and adjusts the brightness. In the experimental example, it is determined whether the image is stopped using a specific threshold value, and the logo is determined based on the determination.

If the logo is assumed to be stationary, the presence or absence of the logo can be detected by sufficiently accumulating the difference value between the before and after frames (N-1 frame, N frame) and comparing them.

The logo detection method of the experimental example compares the front and rear frames (N-1 frame, N frame) in units of blocks based on these characteristics to guess and detect the block including the logo and reduce the brightness of the detected block, . In the process of comparing the before and after frames (N-1 frame, N frame), it is possible to improve the after-image lifetime of the logo part by distinguishing the logo blocks using a specific threshold value and reducing the brightness of the blocks determined as the logo .

As shown in FIG. 4, the experimental example uses a method of accumulating difference values between the before and after frames (N-1 frame, N frame), so that the opaque logo portion and the non-logo portion are easily distinguished through the histogram I was able to.

As shown in FIG. 5, the experimental example uses a method of accumulating difference values between the previous frame and the subsequent frame (N-1 frame, N frame), so that the translucent logo portion and the non-logo portion are easily distinguished through the histogram I could not.

The experimental example is useful for judging a logo (opaque logo) having a similar change in a specified frame unit but it is not suitable for judging a logo (translucent logo) having a different amount of change depending on the screen. This is because a method of judging whether or not the image is stopped by using a specific threshold value and determining whether or not the logo is used is used based on the determination.

As can be seen from the results of the experimental example, in the experimental example, the logo that can be detected is limited according to how the threshold value is set, and the possibility of false detection is increased when the threshold value is set sufficiently high to detect the translucent logo.

[Example]

FIGS. 6 to 8 are views for explaining a logo detection method according to an embodiment of the present invention, FIG. 9 is a diagram for explaining a logo estimation process, FIG. 10 is a diagram for explaining a logo grouping process, FIG. 11 is a diagram for explaining a memory dynamic allocation and storage process, FIG. 12 is a diagram showing the result of detection of an opaque logo and a translucent logo, FIGS. 13 and 14 are views for explaining a block counter update process, FIGS. 16 and 17 are diagrams showing a difference value map of an opaque logo and a translucent logo, and FIGS. 18 and 19 are examples of pixel and block unit compensation. FIG.

6, a method of detecting a logo according to an exemplary embodiment of the present invention includes a logo block sensing step S110, a block extension and grouping step S120, a pixel and a block unit compensation step S150, And adjusts the luminance. The logo detection method performs derivation of a logo candidate group, classification of a logo pixel using an adaptive threshold in a candidate group, derivation of a compensation value, and luminance variation using a compensation value.

As shown in FIGS. 6 and 7, in the logo block sensing step S110, the image is divided into blocks of an appropriate size, and the logo block and the non-logo block are distinguished from each other using the difference between the before and after blocks, To classify the logo candidates. A block can be M (M is an integer of 2 or more) * N (N is an integer of 2 or more), but if the size of the block is too small, the number of block unit comparisons increases. Blocks of appropriate size can be set through experiments. At this time, the minimum unit of one block is defined as a pixel.

The logo block estimation step S110 includes a step S113 of updating the block counter using the difference between the before and after blocks and a step S115 of separating the logo block and the non-logo block using the block counter .

The logo portion of the video with the logo has a characteristic of being stopped when the video has a large change instantaneously. By using this property, a block including a logo can be distinguished from a block including a logo. It is possible to distinguish the logo candidate block from the non-logo block by dividing the image into blocks and limiting the size of the region in which the logo can be included and waiting until the cumulative change of the successive frames becomes the predetermined size.

The size of the region in which the logo can be included is 1% or more of the entire screen of the display panel. However, if the size of the region where the logo can be included is too small, it is difficult to derive the logo candidate group, and there is a possibility that a missing portion occurs. Therefore, it is preferable that the size of the region in which the logo can be included does not exceed 1% to 20% of the entire screen of the display panel, but this may vary depending on the ratio or resolution of the display panel through experiments.

As shown in FIG. 9, in one frame (frame), a logo (running man's battery training race) and a logo estimation (candidate group) block are all detected. However, in the subsequent frames (2 to 3 frames), the size of the region in which the logo can be included (the size of the area in which the logo can be included is limited to 5% of the entire screen of the display panel) The non-logo block is excluded as the counter counter is performed.

Therefore, in this process, the threshold value for determining the difference between the frames before and after the region in which the logo can be included is made large so that the translucent logo can be sufficiently included. In this case, there is a false detection problem in which a block not including a logo is detected, but this is a process of setting a logo candidate group, so that it does not have any influence such as an error compensation.

In the block expansion and grouping step (S120), the logo candidates are classified into blocks, and then K (K is an integer of 1 or more) blocks adjacent to the left, right, upper, and lower blocks so as to correspond to a logo of a specific shape and size, And Grouping. In this step, a candidate group is formed between adjacent blocks so that an adaptive thresholding can be applied after extending the logo candidate group, and grouping of the same logo candidates for the division between logos and logos .

As shown in FIG. 10, the logo candidate group C is classified in units of blocks (FIG. 10A), and the logo candidate group is extended (EC) to one block adjacent to the logo candidate group (FIG. 10B) (C in Fig. 10), the initially detected logo candidate group C is grouped into the first group 1, the second group 2 and the third group 3 in an expanded form and a group form .

After performing the block extension and grouping step S120, the pixel and block unit compensation step S150 may be performed immediately. However, in order to improve the detection performance of the translucent logo, it is preferable to perform the memory dynamic allocation and storage step S130 and the pixel counter update step S140 by applying an adaptive thresholding as follows.

As shown in FIGS. 6, 8, and 11, in the memory dynamic allocation and storage step (S130), a block determined as a logo is allocated and stored in a memory. By dynamically allocating memory, it is possible to allocate a logo block of arbitrary position and arbitrary size (memory allocation can be reduced because it can be allocated smaller than a predetermined size) using only a predetermined size of memory. For example, the memory may be set to store 600 blocks, and one block may store 16 * 16 pixels, but is not limited thereto.

6, FIG. 8, and FIG. 12 through FIG. 17, in the pixel counter update step S140 by applying the adaptive thresholding, the pixel counter in the block classified as the same (same) And an adaptive thresholding is obtained using an average of difference values between the subsequent frames. The adaptive thresholding is a value for estimating (or detecting) a block having a relatively small amount of change in a frame. The adaptive threshold value allows easy estimation (or detection) of different transparency of the logo. With adaptive thresholding, a pixel counter can be stored using a dynamically allocated memory, separating the logo from the non-logo on a pixel-by-pixel basis.

After classifying the logo region of the image into a logo candidate group, an adaptive thresholding is obtained by calculating an average of difference values between the previous and next frames in units of pixels within a block determined as one candidate of a logo. For separating logos and non-logos, use adaptive thresholding for translucent logo detection. Logo candidates are grouped together into the same logo candidates. Thus, while the same logo candidate group applies the same adaptive threshold, different adaptive thresholds may be applied between different logo candidate groups.

The upper left image of FIG. 12 (a) is an image capturing an opaque logo (running training battery training race), and the lower left image of FIG. 12 (a) is a difference map of the before and after frames for the opaque logo map, and the right image of FIG. 12 (a) is a histogram distribution chart of the opaque logo.

As can be seen from the histogram of the opaque logo, it is possible to detect the logo even if a sufficiently small threshold is used because the difference between the before and after frames of the pixel converges to zero.

The upper left image of FIG. 12 (b) is an image (SBS HD) capturing a translucent logo, and the lower left image of FIG. 12 (b) is a difference map of the before and after frames for the translucent logo , And the image on the right side of FIG. 12 (b) is a histogram distribution diagram of the translucent logo.

As can be seen from the histogram of the translucent logo, this occurs when the difference between the before and after frames of the pixel is not zero. In this case, if a sufficiently small threshold is used, the logo can be judged to be not a logo have. For this reason, it is necessary to use different threshold values for each frame.

Therefore, in order to detect translucent logos, adaptive thresholding should be used in which at least N (N is an integer equal to or greater than 1) frames are varied in value.

As shown in FIG. 12, in the case of the translucent logo (b), although the pixel value varies greatly according to the image of the opaque logo (a), when the degree of the difference value is continuously accumulated, . This difference value is converged to a value smaller than the non-logo portion, so that the translucent logo can be distinguished.

As shown in FIG. 13, when the pixel counter is stored in the memory, the count is incremented by one when the difference value is smaller than the average (average 3) (0, 1 and 2) , 4, and 5) are counted down to generate a pixel counter for each logo candidate block.

If the counter value is continuously obtained for a predetermined time or longer, the counter has a sufficiently large counter value in the case of a logo, and a sufficiently small counter value in case of a non-negative value. The average of this counter value can be used to distinguish the logos again. Therefore, as shown in FIG. 14, the pixel and block counter values can be used as a pixel reducing pixel luminance and a block unit compensation value (Block Gain). A pixel counter or a block counter may be used to provide a block gain map for pixel-level or block-level compensation.

Fig. 15 shows an example in which a translucent logo is compensated (Compensated value) using a pixel counter (b) for an original translucent logo (a).

As can be seen from the opaque logo and translucent logo frame difference value map shown in FIGS. 16 and 17, when determining the adaptive thresholding, if an average of difference values between the before and after frames in the group is used effective.

However, this determined adaptive thresholding does not precisely distinguish all pixels. Therefore, it is possible to separate the logo and the non-logo pixel based on the cumulative sum in order to perform the above process repeatedly for several frames and determine the logo and the non-logo. In this process, adaptive thresholding is not fixed to one value but is variable to a first adaptive threshold value, a second adaptive threshold value or the like (th1 and th2 ).

As shown in FIGS. 16, 18 and 19, after storing or updating the pixel counter, the brightness of the logo detected through the pixel and block unit compensation step (S150) is adjusted.

As shown in FIG. 18, in the pixel and block unit compensation step S150, the brightness of the detected logo can be lowered by (1) pixel, (2) block or (3) pixel and block. In addition, as shown in FIG. 19, in the pixel and block unit compensation step S150, the brightness of the screen may be lowered while maintaining the brightness of the detected logo.

As can be seen from FIGS. 18 and 19, when the pixel and the block unit compensation are performed on the detected logo, the brightness can be partially varied (reduced), thereby minimizing the deterioration of image quality and improving the life span and image retention life can do.

FIG. 20 is a block diagram schematically showing a part of a display apparatus according to an embodiment of the present invention, and FIG. 21 is a block diagram of the timing controller shown in FIG.

20 and 21, the timing control unit 120 receives the data signal DATA from the image supply unit 110 in cooperation with the frame memory 160 and the logo memory 165, And then outputs the compensation data signal CDATA.

The frame memory 160 stores the data signal DATA supplied to the timing controller 120 on a frame-by-frame basis. The timing controller 120 stores or retrieves a previous frame and a next frame (N-1 frame, N frame) (or a previous frame and a current frame) in the frame memory 160. The logo memory 165 stores a block (position, size, etc.) determined as a logo, a pixel counter, and the like. The timing control unit 120 stores or retrieves a block (position, size, etc.) determined as a logo, a pixel counter, and the like in the logo memory 165.

The timing control unit 120 includes a difference value calculating unit 121, a logo candidate group estimating unit 123, a logo candidate group expanding and grouping unit 125, a memory allocating unit 126, an adaptive threshold setting unit 127, And a compensation unit 129.

The difference value calculator 121 divides the image into blocks of an appropriate size and calculates (calculates) a difference between before and after blocks. A block can be M (M is an integer of 2 or more) * N (N is an integer of 2 or more), but if the size of the block is too small, the number of block unit comparisons increases. Blocks of appropriate size can be set through experiments. At this time, the minimum unit of one block is defined as a pixel.

The logo candidate group estimator 123 classifies the logo candidate group and the non-logo block based on the difference value between the before and after blocks, and classifies the logo candidate group on a block-by-block basis. The logo candidate group estimator 123 updates the block counter based on the difference between the previous and next blocks, and can distinguish the logo candidate block from the non-logo block using a block counter (counter value).

The logo candidate group estimating unit 123 divides the image into blocks, limits the size of an area where the logo can be included, and waits until the cumulative change of the consecutive frames becomes a predetermined size. Then, it is possible to distinguish the logo candidate block from the non-logo block.

On the other hand, the size of the area in which the logo can be included is larger than the size of one block designated to identify the logo. However, if the size of the region where the logo can be included is too small, it is difficult to derive the logo candidate group, and there is a possibility that a missing portion occurs. Therefore, it is preferable that the size of the region in which the logo can be included does not exceed 1% to 20% of the entire screen of the display panel, but this may vary depending on the ratio or resolution of the display panel through experiments.

The logo candidate group expansion and grouping unit 125 classifies the logo candidate group in units of blocks and then groups the logo candidates to K (K is an integer of 1 or more) blocks adjacent to the left, right, upper and lower sides so as to correspond to the logo of a specific shape and size Expands and groups candidate groups.

The logo candidate group expanding and grouping unit 125 creates a candidate group between adjacent blocks so that an adaptive thresholding can be applied after the logo candidate group is expanded, The same logo candidates are grouped together.

The memory allocation unit 126 allocates and stores a block determined as a logo in the logo memory 165. [ When the logo memory 165 is dynamically allocated, it is possible to allocate a logo block of arbitrary position and arbitrary size (which can be allocated smaller than a predetermined size, thereby reducing memory usage) by utilizing only a memory of a predetermined size. For example, the logo memory may be set to store 600 blocks, and one block may store 16 * 16 pixels, but is not limited thereto.

The adaptive threshold setting unit 127 obtains an adaptive thresholding using an average of difference values between pixels before and after a pixel in a block classified into the same (same) logo candidate group. The adaptive threshold setting unit 127 stores a pixel counter using the dynamically allocated logo memory 165 by separating the logo and the non-logo on a pixel-by-pixel basis through an adaptive thresholding .

The adaptive threshold value setting unit 127 distinguishes the logo from the non-logo by estimating a pixel having a small change amount in contrast to the surrounding color within the expanded log candidate group based on the adaptive threshold value. The adaptive threshold value setting unit 127 obtains an adaptive thresholding value at which at least N (N is an integer equal to or greater than 1) frames are changed for translucent logo detection when the logo and the non-logo are distinguished. Logo candidates are grouped together into the same logo candidates. Thus, while the same logo candidate group applies the same adaptive threshold, different adaptive thresholds may be applied between different logo candidate groups.

The data compensator 129 performs pixel and block unit compensation on the detected logo to provide a compensation data signal CDATA. The data compensating unit 129 compensates the brightness of the detected logo by lowering the brightness of the detected logo to (1) pixel, (2) block or (3) pixel and block or maintaining the brightness of the detected logo Can be performed.

The data compensating unit 129 omits the compensation process and outputs a data signal DATA corresponding to the original if the compensation for the logo is unnecessary. The data compensating unit 129 can perform pixel and block unit compensation on the detected logo to partially vary the luminance (reduce), thereby minimizing the deterioration of the image quality, thereby improving the life of the display panel and improving the after- .

When the pixel and block unit compensation are performed on the logo, the problem that the afterimage occurs on the display panel due to the difference in degree of deterioration between the region deteriorated by the logo and the peripheral region thereof, the display quality and the life- .

One embodiment of the present invention requires pixel-by-pixel memory because pixel and block-based compensation is performed on the logo. Accordingly, when a device (H / W) is implemented, a block classified as a logo candidate is allocated to a memory in a process of defining a logo size (using only a limited size memory and dynamic allocation is used) The memory increase (or shortage) problem can be solved by releasing (deleting) the memory.

An embodiment of the present invention is more effective when applied to an organic light emitting display. This is because the organic light emitting diode device exhibits remarkable luminance and lifetime degradation characteristics due to deterioration (deterioration of image quality, deterioration of device, and the like) during long-term (time) driving with respect to the liquid crystal device. Therefore, by detecting an opaque logo or translucent logo on a pixel-by-pixel basis using a single embodiment of the present invention, image quality deterioration factors can be minimized to partially improve the image quality of the organic light emitting display device have.

INDUSTRIAL APPLICABILITY The present invention has the effect of detecting the still logo including the translucent logo and changing the brightness without deteriorating the image quality, thereby prolonging the life of the display panel and improving the after-image life. Further, the present invention has the effect of improving and improving the display quality by lowering the influence of the artifacts generated when compensating the detected logos in block units by assigning compensation values in pixel units. The present invention has the effect of classifying a change in motion between frames into an adaptive threshold and detecting and compensating for a translucent logo based on the change. In addition, the present invention has the effect of improving the memory increase (or shortage) problem by dynamically allocating memory of a predetermined size for pixel-by-pixel compensation after deriving a logo candidate group.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive. In addition, the scope of the present invention is indicated by the following claims rather than the detailed description. Also, all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present invention.

110: image supply unit 120: timing control unit
130: Gate driver 140: Data driver
150: display panel 121: difference value calculating section
123: Logo candidate group estimation 125: Logo candidate group expansion and grouping unit
126: memory allocation unit 127: adaptive threshold value setting unit
129: Data Compensation Unit

Claims (10)

A difference value calculation unit for dividing the image into blocks and calculating difference values between the previous and next blocks;
A logo candidate group dividing the logo candidate block and the non-logo block based on the difference value between the before and after blocks and classifying the logo candidate group on a block-by-block basis;
A logo candidate group expanding and grouping unit for expanding the logo candidate group and grouping the same logo candidate groups together;
An adaptive threshold value setting unit for obtaining an adaptive threshold value and discriminating a logo and a non logo from the extended logo candidate group based on the adaptive threshold value; And
And a data compensating section for compensating for the detected logo. The method according to claim 1,
The adaptive threshold setting unit
And obtains the adaptive threshold value by using an average of difference values between pixels before and after the pixels in the block classified as the same logo candidate group. The method according to claim 1,
The adaptive threshold
Wherein the value changes at least every N (N is an integer of 1 or more) frames. The method according to claim 1,
The logo candidate group expansion and grouping unit
And expanding the logo candidate group to K (K is an integer of 1 or more) blocks adjacent to the logo candidate group and grouping the same logo candidate groups. The method according to claim 1,
Further comprising a memory allocation unit that dynamically allocates the logo memory so that a block classified as the logo candidate group is allocated to the logo memory while a block excluded from the logo candidate group is deleted from the logo memory. The method according to claim 1,
The data compensation unit
Wherein the brightness of the detected logo is compensated in units of pixels, blocks or pixels and blocks. Dividing the image into blocks, calculating difference values between the previous and next blocks, classifying the logo candidate group and the non-logo block based on the difference between the previous and next blocks, and classifying the logo candidate group on a block basis;
Expanding the logo candidate group and grouping the same logo candidate groups;
Determining an adaptive thresholding and separating a logo and a non-logo in the expanded logo candidate group based on the adaptive threshold value; And
And performing compensation for the detected logo. 8. The method of claim 7,
Wherein the step of classifying the logo candidates on a block-
Updating the block counter using the difference between the previous and next blocks, and separating the log candidate block and the non-logo block using the block counter. 8. The method of claim 7,
The step of distinguishing the logo from the non-logo in the extended logo candidate group
Wherein the adaptive threshold value is obtained by using an average of difference values between pixels before and after a pixel within a block classified as the same logo candidate group. 8. The method of claim 7,
The step of grouping the same logo candidate groups
Expanding the logo candidate group to K (K is an integer equal to or greater than 1) blocks adjacent to the logo candidate group and grouping the same logo candidate groups.

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