KR20190017286A - Method for Image Processing and Display Device using the same - Google Patents

Abstract

Provided is an image processing method for generating a compensation frame between an N^th frame and an (N+1)^th frame and forming a motion compensation image based on a first image in the N^th frame and a second image in the (N+1)^th frame within the compensation frame. To this end, the image processing method comprises the steps of: analyzing a feature of the first and second images to analyze whether a background image and a foreground image are present; defining an artifact occurring region according to whether the background image and the foreground image are present; and selecting at least one compensation scheme of forward and backward motion compensations respectively using the first and second images by considering the artifact occurring region.

Description

TECHNICAL FIELD [0001] The present invention relates to an image processing method and a display device using the same,

The present invention relates to an image processing 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 use of display devices such as an organic light emitting display (OLED), a liquid crystal display (LCD), and a plasma display panel (PDP) is increasing.

Some of the above-described display devices, for example, a liquid crystal display device or an organic light emitting display device, can supply a scan signal, a data signal, or the like to subpixels included in a display panel, have.

Organic electroluminescent display devices, liquid crystal display devices and the like belong to hold-type display devices, and plasma display devices and the like belong to impulse type display devices. The hold type display device may observe a motion blur in a moving picture and may deteriorate the picture quality compared to an impulse type display device.

A hold-type display device uses an image processing method called Frame Rate Up-Conversion (FRUC) technique to improve motion blur. The frame rate upconversion technique is a technique of inserting a new frame between frames of an input original image, and can improve motion blur without reducing the brightness of the hold type display device.

The frame rate upconversion technique mainly includes Motion Estimation (ME) and Motion Compensation. The motion estimation (ME) is a process of calculating a motion of an object between consecutive frames to obtain a motion vector (MV) corresponding to a motion change. The motion compensation (MC) And generating a new frame image for interpolation based on the obtained motion vector (MV). However, the image processing method proposed in the prior art requires a buffer memory with a high capacity when a new frame image is generated, which is required to be improved.

The present invention for solving the above-mentioned problems of the background art predicts errors that may occur due to buffer size reduction during image processing and minimizes artifacts that may occur in an actual image. The present invention also improves the image quality while reducing the size of the buffer.

According to an aspect of the present invention, there is provided a method for generating a compensation frame between an Nth frame and an (N + 1) -th frame and generating a compensation frame based on a first image in the Nth frame and a second image in the And a compensated image is formed. An image processing method includes analyzing characteristics of a first image and a second image to analyze presence / absence of a background image and a foreground image, defining an artifact occurrence area according to presence or absence of a background image and a foreground image, And selecting at least one compensation scheme among forward motion compensation using the first image and backward motion compensation using the second image in consideration of the generated region.

In the step of selecting the compensation scheme, one compensation scheme may be selected, and the size of the buffer memory required for the forward motion compensation and the backward motion compensation may be different.

In the step of selecting the compensation scheme, the size of one of the forward motion buffer for forward motion compensation and the backward motion buffer for backward motion compensation can be reduced.

The range for reducing the size of one of the forward motion buffer and the backward motion buffer may be based on the intermediate motion vector field corresponding to the set of motion vectors scaled by the size of the compensation frame.

The intermediate motion vector field includes a forward intermediate motion vector field of the foreground image, a forward intermediate motion vector field of the background image, a backward intermediate motion vector field of the foreground image, and a backward intermediate motion vector field of the background image .

The step of reducing the size of one of the forward motion buffer and the backward motion buffer considers the area where no error occurs and the area where the error occurs, the size of the area where the error occurs, Can be determined as the sum of the area of occurrence.

The size of the motion buffer can be reduced with a low specific gravity in consideration of the occurrence of an artifact in an area where an error occurs.

In another aspect, the present invention provides a display device including a MEMC processing section and a display panel. The MEMC processing unit generates a compensation frame between the Nth frame and the (N + 1) th frame, and forms a motion compensated image based on the first image in the Nth frame and the second image in the (N + 1) th frame in the compensation frame. The display panel displays an image based on the image output from the MEMC processing unit. The MEMC processor analyzes the presence or absence of the background image and the foreground image by analyzing the characteristics of the first image and the second image, defines an artifact occurrence area according to presence or absence of the background image and the foreground image, And selects at least one of compensation methods of forward motion compensation using the first image and backward motion compensation using the second image.

The MEMC processing unit may select at least one compensation method of forward motion compensation and private backward motion compensation as well as different sizes of the buffer memory required for the forward motion compensation and the backward motion compensation.

The size of one of the forward motion buffer for forward motion compensation and the backward motion buffer for backward motion compensation can be reduced by the operation of the MEMC processing unit.

The present invention has an effect of predicting an error that may occur due to a reduction in size of a buffer in image processing and minimizing artifacts that may occur in an actual image. Further, since the present invention is based on a buffer size increase and reduction factor analysis technique, the image quality can be improved while reducing the size of the buffer.

1 is a schematic block diagram of a display device;
Fig. 2 is a schematic circuit configuration example of a subpixel; Fig.
3 is a cross-sectional exemplary view of a display panel.
4 is a diagram for explaining a basic structure of a motion judgment;
5 is a diagram for explaining a basic structure of motion compensation;
6 is a diagram for explaining a unidirectional motion compensation method according to the first experimental example;
7 is a view for explaining a bidirectional motion compensation method according to a second experimental example;
FIG. 8 and FIG. 9 are diagrams for explaining a motion compensation scheme of an experimental example and a motion vector field set for performing the motion compensation scheme; FIG.
10 is an exemplary diagram for explaining the size of the buffer memory when the motion compensation method of the experimental example is used.
11 is a first exemplary view for explaining an embodiment of the present invention.
12 is a second exemplary view for explaining another embodiment of the present invention.
13 is an exemplary diagram for explaining a buffer size reduction error;
14 is an exemplary diagram for explaining a relationship between a buffer size reduction error and an actual motion compensation video error;
15 is a diagram for explaining forward motion compensation and backward motion compensation;
16 is a view for explaining a covered area and an unburned area;
17 is a diagram for explaining a relationship between a size of a buffer and an intermediate motion vector field;
18 is a diagram for explaining a method of determining an intermediate motion vector field;
19 illustrates a first principle associated with selective reflection of forward motion compensation and backward motion compensation;
Figure 20 illustrates a second principle related to selective reflection of forward motion compensation and backward motion compensation;
21 is a graph that linearly represents the first and second principles;
22 is a graph for explaining selective reflection of forward motion compensation and backward motion compensation for buffer size reduction;
23 is an illustration of an example of a forward motion compensation method in accordance with the prior art;
24 illustrates an example of a backward motion compensation method according to the prior art;
25 is an illustration of an exemplary motion compensation method in accordance with an embodiment.
26 is a first exemplary view showing a partial configuration of a display device according to an embodiment of the present invention;
27 is a second exemplary view showing a part of the configuration of a display device according to an embodiment of the present invention;
Figures 28 to 30 illustrate exemplary differences between a conventional method and an exemplary method.

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 according to the present invention is implemented as a television, a video player, a personal computer (PC), a home theater, a smart phone, an augmented / virtual reality device and the like. The display panel of the display device may be a hold type such as a liquid crystal display panel, an organic light emitting display panel, an electrophoretic display panel or the like, but is not limited thereto.

FIG. 1 is a schematic block diagram of a display device, FIG. 2 is a schematic circuit configuration example of a subpixel, and FIG. 3 is an exemplary cross-sectional view of a display panel.

1, a display device according to an exemplary embodiment of the present invention includes an image processing unit 110, a timing control unit 120, a data driving unit 130, a scan driving unit 140, and a display panel 150 .

The image processing unit 110 outputs a data enable signal DE together with a data signal DATA supplied from the outside. The image processing unit 110 may output at least one of a vertical synchronizing signal, a horizontal synchronizing signal, and a clock signal in addition to the data enable signal DE, but these signals are omitted for convenience of explanation.

The timing controller 120 receives a data signal DATA from a video processor 110 in addition to a data enable signal DE or a driving signal including a vertical synchronizing signal, a horizontal synchronizing signal, and a clock signal. The timing controller 120 includes a gate timing control signal GDC for controlling the operation timing of the scan driver 140 and a data timing control signal DDC for controlling the operation timing of the data driver 130, .

The data driver 130 samples and latches the data signal DATA supplied from the timing controller 120 in response to the data timing control signal DDC supplied from the timing controller 120 and converts the sampled data signal into a gamma reference voltage . The data driver 130 outputs the data signal DATA through the data lines DL1 to DLn. The data driver 130 may be formed in the form of an IC (Integrated Circuit).

The scan driver 140 outputs 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 scan driver 140 outputs a scan signal through the scan lines GL1 to GLm. The scan driver 140 is formed in the form of an integrated circuit (IC) or a gate-in-panel (GATE) panel in the display panel 150.

The display panel 150 displays an image corresponding to the data signal DATA and the scan signal supplied from the data driver 130 and the scan driver 140. The display panel 150 includes sub-pixels SP that operate to display an image.

The subpixels SP include a red subpixel, a green subpixel, and a blue subpixel or a white subpixel, a red subpixel, a green subpixel, and a blue subpixel. The display panel 150 may be divided into a liquid crystal display panel, an organic light emitting display panel, and an electrophoretic display panel according to the configuration of the pixel circuit PC included in the subpixels SP.

As shown in FIG. 2, one subpixel SP is supplied with a scan signal supplied through a switching transistor SW and a switching transistor SW connected to a scan line GL1 and a data line DL1, And a pixel circuit (PC) that operates in response to the data signal. When the display panel is selected as the organic light emitting display panel, the pixel circuit PC of the subpixel SP can be configured to further include various types of compensation circuits in addition to the driving transistor, the storage capacitor, and the organic light emitting diode.

3, the display panel 150 includes a substrate (or a thin film transistor substrate) 150a having a display area AA and a non-display area NA, and a protective film (or a protective substrate) 150b. . In the display area AA, the pixel P is formed based on the circuit described in Fig. Pixels P arranged on the display area AA include red (R), white (W), blue (B) and green (G) subpixels. The subpixels of red (R), white (W), blue (B), and green (G) may be arranged horizontally or vertically on the substrate 150a. However, the arrangement order of the subpixels described above is only one example, and may be variously changed according to the implementation of the display panel 150. [ Also, the subpixels may be red (R), blue (B), and green (G) may be one pixel (P).

A display device such as the liquid crystal display panel or the organic light emitting display panel described above belongs to a hold type display device and a display device implemented by a plasma display panel belongs to an impulse type display device. The hold type display device may observe a motion blur in a moving picture and may deteriorate the picture quality compared to an impulse type display device.

A hold-type display device uses an image processing method called Frame Rate Up-Conversion (FRUC) technique to improve motion blur. The frame rate upconversion technique is a technique for increasing the frame rate and inserting a new frame between the frames of the input original image. The frame rate upconversion technique improves the motion blur without reducing the luminance of the hold-type display device .

The frame rate upconversion technique mainly includes Motion Estimation (ME) and Motion Compensation. The motion estimation (ME) is a process of calculating a motion of an object between consecutive frames to obtain a motion vector (MV) corresponding to a motion change. The motion compensation (MC) And generating a new frame image for interpolation based on the obtained motion vector (MV).

FIG. 4 is a diagram for explaining a basic structure of motion judgment, and FIG. 5 is a diagram for explaining the basic structure of motion compensation.

As shown in Fig. 4, moving pictures are input in frame units. When a rectangular box image in the Nth frame (frame [n]) is defined as a second image (image2) in the first image (Image1) and in the (N + 1) A motion vector (MV) expresses the motion of image information from the first image (Image1) to the second image (image2) in the horizontal and vertical directions. The process of obtaining a motion vector is called motion estimation (ME).

A block matching method is generally used for performing motion matching based on a preset block unit between the current frame data and previous frame data for cost reduction or the like.

As shown in FIG. 5, in addition to motion determination information, a second image (image2) of an Nth frame (frame [n]) or an N + 1th frame (frame [n + Or a process of generating an Nx frame (frame [nx]) (hereinafter referred to as a compensation frame) using a plurality of pieces of image information including the image information is referred to as motion compensation (MC). The rectangular box image generated in the N.X frame (frame [n.x]) (hereinafter referred to as the compensation frame) by the compensation operation at this time is referred to as a motion compensated image (MCI).

<Experimental Example>

FIG. 6 is a view for explaining the unidirectional motion compensation method according to the first experimental example, FIG. 7 is a view for explaining the bidirectional motion compensation method according to the second experimental example, and FIGS. 8 and 9 are diagrams for explaining the motion compensation FIG. 10 is an exemplary diagram for explaining the size of the buffer memory when using the motion compensation method of the experimental example.

As shown in FIG. 6, the unidirectional motion compensation scheme <Uni-D MC example> performs motion compensation using only one of the first image (image 1) or the second image (image 2). It is called "uni-directional MC" because it uses only unidirectional video.

As shown in FIG. 7, the bidirectional motion compensation scheme < Bi-D MC example > performs motion compensation using a plurality of images including a first image image1 and a second image image2. It is called "bi-directional MC" because it uses both images in both directions.

6 and 7, the process of performing motion compensation using the first image image1 is referred to as forward MC (FW-MC), and the process of performing motion compensation using the second image (image2) May be referred to as backward motion compensation (BW-MC).

8 and 9, the unidirectional and bidirectional motion compensation schemes may be configured to perform one or more of the forward motion compensation (FW-MC) and the backward motion compensation (BW-MC) ] In the forward direction (+) or the reverse direction (-). At this time, a set of motion vectors obtained by scaling the size of the compensation frame (frame [n.x]) is called an intermediate motion vector field (IMVF). In motion compensation, the buffer size (BFS) of the buffer memory of the first image (image1) or the second image (image2) is determined according to the range of the intermediate motion vector field (IMVF) value.

6 and 10, only one of the forward motion compensation (FW-MC) or the backward motion compensation (BW-MC) is performed according to the unidirectional motion compensation scheme according to the first experimental example. As a result, since the unidirectional motion compensation scheme < Uni-D MC > uses only a selected one of the first image image1 or the second image image2, the buffer memory also includes the forward motion buffer FW- Only the motion buffer (BW-BFS) is required.

Since the unidirectional motion compensating scheme < Uni-D MC > uses only a selected one of the first image (image1) or the second image (image2), the degree of freedom in allocating buffer memory is high. However, this method is not free from deterioration in image quality such as motion artifacts when a moving image is implemented.

As shown in FIGS. 7 and 10, both the forward motion compensation (FW-MC) and the backward motion compensation (BW-MC) are performed according to the bidirectional motion compensation scheme according to the second experimental example. As a result, since the bidirectional motion compensation scheme < Bi-D MC > uses both images over the first image image1 and the second image image2, the buffer memory also includes the forward motion buffer FW- All motion buffers (BW-BFS) are required.

Since the bidirectional motion compensation method < Bi-D MC > uses both of the images over the first image (image1) and the second image (image2), it is relatively free from image deterioration such as motion artifacts. However, this method requires more than twice the buffer memory as compared with the unidirectional motion compensation method.

Therefore, in the image processing method according to the experimental examples, when generating a compensation frame (a new frame image), it is required to preserve image quality (lower image quality deterioration) while reducing the buffer memory size.

<Examples>

FIG. 11 is a first exemplary view for explaining an embodiment of the present invention, and FIG. 12 is a second exemplary view for explaining another embodiment of the present invention.

11, the embodiment of the present invention provides an optional motion compensation scheme capable of reducing the size of the buffer memory while increasing the degree of freedom from deterioration in image quality at the time of generating a compensation frame (new frame image) do.

Embodiments of the present invention provide the size of the backward motion buffer (BW-BFS) for backward motion compensation (BW-MC) rather than the size of the forward motion buffer (FW-BFS) for forward motion compensation Lower. In other words, the size of the forward motion buffer (FW-BFS) is kept the same as that of the prior art, but the size of the backward motion buffer (BW-BFS) is lower than that of the prior art.

12, when the compensation frame (new frame image) is generated, the size of the buffer memory can be reduced while increasing the degree of freedom from the deterioration of the image quality. In addition, as in the second exemplary embodiment shown in FIG. 12, .

Yet another embodiment of the present invention is the use of a forward motion buffer (FW-BFS) for forward motion compensation (FW-MC) rather than a backward motion buffer (BW-BFS) size for backward motion compensation Decrease size. In other words, the size of the backward motion buffer (BW-BFS) is kept the same as that of the prior art, but the size of the forward motion buffer (FW-BFS) is reduced compared to the conventional case.

FIG. 13 is an exemplary diagram for explaining a buffer size reduction error, and FIG. 14 is an exemplary diagram for explaining a relationship between a buffer size reduction error and an actual motion compensation video error.

13, when the compensation frame (frame [nx]) having the motion compensation image MCI is generated in the bi-directional motion compensation scheme, the size of the backward motion buffer BW-BFS is reduced A reduction error (reduction error) occurs as the buffer size is reduced. This is because the size of the backward motion buffer (BW-BFS) is reduced without considering the characteristics of the second image (image2) of the (N + 1) th frame (frame [n + 1]). Theoretically, the reduction error (reduction error) is said to be proportional to the size of the buffer to be reduced.

However, as shown in FIG. 14, when the size of the buffer to be reduced is determined and experimented, the actual motion compensated image error (MCI error) may be different according to the intermediate motion vector field (IMVF) value of the image. .

Therefore, it can be concluded that MCI error can be minimized if the size of either buffer is effectively reduced depending on the characteristics of the image. However, in order to effectively reduce the size of the buffer, the following considerations must be considered, including the analysis of motion compensation, the relationship between foreground and background images, and the principle of weighting for selectively reflecting motion compensation. Hereinafter, the conditions for achieving the first example will be described as a reference.

FIG. 15 is a view for explaining the forward motion compensation and the backward motion compensation, FIG. 16 is a view for explaining a covered area and an unkembered area, and FIG. 17 is a diagram for explaining the relationship between the size of the buffer and the intermediate motion vector field FIG. 18 is a view for explaining a method of determining an intermediate motion vector field, FIG. 19 is a diagram for explaining a first principle related to selective reflection of forward motion compensation and backward motion compensation, and FIG. 20 is a diagram for explaining the second principle related to the selective reflection of the forward motion compensation and the backward motion compensation, FIG. 21 is a graph that linearly represents the first and second principles, FIG. FIG. 5 is a graph illustrating the selective reflection of the forward motion compensation and the backward motion compensation.

In FIGS. 15 to 17, 19 and 20, a first image (image1) in the Nth frame, a second image (image2) in the N + 1th frame, and a motion compensated image (MCI) A background image BG and a foreground image FG of a rectangular shape are present together. The circular background image (Background; BG) is in a stopped state, while the rectangular foreground image (Foreground; FG) is in a moving state. That is, an example of generating a compensation frame and a motion compensation image based on a foreground (FG) image of a rectangle moving in a background image BG of a stationary circular shape will be described below.

15, a circular background image (BG) and a rectangular foreground image (FG) may exist in the first image (image1) and the second image (image2). Therefore, it is necessary to analyze the existence of the background (BG) and the foreground (FG) by analyzing the characteristics of the first image (image1) and the second image (image2).

In the case where a background image (BG) and a foreground image (FG) exist in an image, an intermediate motion vector field included in the motion compensated image (MCI) in the compensation frame includes a forward intermediate motion vector field FW-IMVF_FG) of the background image, the forward intermediate motion vector field FW-IMVF_BG of the background image, the backward intermediate motion vector field BW-IMVF_FG of the foreground image, and the backward intermediate motion vector field BW- And they are distinguished from each other. MV_BG is the motion vector of the background image, and MV_FG is the motion vector of the foreground image.

As shown in Fig. 16, when generating the motion compensated image MCI based on the forward intermediate motion vector field FW-IMVF_BG of the background image, the area where the artifact occurs is defined as the uncovered area Uncovered . When the motion compensated image MCI is generated based on the backward intermediate motion vector field BW-IMVF_BG of the background image, the area where the artifact occurs is defined as a covered area.

As can be seen from the drawings, the uncovered area (Uncovered) does not generate artifacts only by the forward motion compensation. Therefore, when generating an uncovered area (Uncovered), the size of the backward motion buffer for backward motion compensation can be reduced instead of maintaining the size of the forward motion buffer for forward motion compensation.

Alternatively, the covered area generates artifacts in backward motion compensation. Therefore, when creating the covered area, it is preferable to keep the size of the forward motion buffer for forward motion compensation as it is, but to increase the specific gravity so that no artifacts are generated.

On the other hand, since the unidirectional motion compensation method mainly uses only the forward motion compensation, artifact generation in the uncovered area (Uncovered) can not be reduced through the backward motion compensation. Since bidirectional motion compensation uses both forward motion compensation and backward motion compensation, it is possible to reduce the occurrence of artifacts in the uncovered area through backward motion compensation. In addition, both unidirectional and bidirectional motion compensation schemes comprise forward motion compensation to construct motion compensated images, so that the probability of occurrence of artifacts in the covered area is relatively low.

16 and 17, in order to generate the motion compensated image MCI for the uncovered area Uncovered, unlike the covered area, the backward intermediate motion vector field BW-IMVF_BG ) That is, an intermediate motion vector field of the background image is required. In addition, there is also a backward intermediate motion vector field (BW-IMVF_FG) of the foreground image around the uncovered area (Uncovered).

The size of the buffer is related to the intermediate motion vector field. In order to effectively reduce the size of the buffer, the intermediate motion vector field (IMVF_BG) of the background image and the intermediate motion vector field (IMVF_FG) of the foreground image are used .

The intermediate motion vector field IMVF_BG of the background image includes a single or plural forward motion vector FW-MV, a backward motion vector BW-MV, a forward intermediate motion vector field FW-IMVF, Field (BW-IMVF). The method is not limited because there may be various methods, such as a method of using motion information in a region having a high probability of being a background, a maximum frequency in a single frame or a plurality of frames.

As shown in FIG. 18, the intermediate motion vector field IMVF_FG of the foreground image includes M (M is an integer of 4 or more, but nine in the drawing) of the current blocks, (IP, jQ) to (i + P, j + Q) are selected to obtain the largest difference from the intermediate motion vector field IMVF_BG of the background image. In the above description, the predetermined distance may be P = 2 in the vertical direction and Q = 4 in the horizontal direction, but is not limited thereto.

The intermediate motion vector field IMVF_FG of the foreground image is set to a value having the largest difference from the intermediate motion vector field IMVF_BG of the background image among the candidates (iP, jQ) to (i + P, j + Because the probability that the intermediate motion vector field having a small difference from the intermediate motion vector field IMVF_BG of the background image in the local candidate region is the intermediate motion vector field IMVF_BG of the background image is the highest.

The present invention takes into consideration one or more of the principles described below, selectively reflecting either forward motion compensation or backward motion compensation in view of the foregoing to effectively reduce buffer size.

As shown in FIG. 19, it is desirable to reduce artifacts in both cases where the value of the backward intermediate motion vector field (BW-IMVF) in the uncovered area (Uncovered) is close to the background or close to the foreground.

Therefore, in the case of selectively reflecting the forward motion compensation and the backward motion compensation, the present invention determines the direction of increasing the reflection specific weight (weight) of the backward motion compensation in the uncovered area (Uncovered) It is decided by one principle.

However, if background image information is changed and new image information is present at the boundary between the foreground and the background of the second image (image2), a new artifact occurs in the backward intermediate motion vector field (BW-IMVF_FG) of the foreground image .

In this case, it is contrary to the first principle of increasing the proportion of reflection of backward motion compensation in the uncovered area (Uncovered). An example in which new image information (?) Appears at the boundary between the foreground and the background of the second image (image2) can be found by comparing FIG. 19 and FIG. At this time, the following second principle can be followed.

As shown in FIG. 20, in the motion compensation process, it is difficult to grasp the characteristics of the image with respect to the boundary between the foreground image FG and the background image BG. Therefore, the probability that new image information (?) Appears at the boundary between the foreground image FG of the second image image 2 and the background image BG is defined and determined to be approximately?.

If you define and judge it like this, you can interpret and cope with occurrence twice at 50% level instead of assuming that artifact occurs once at 100% level. However, the degree of this problem is low in real images. Therefore, the specific gravity w of the intermediate motion vector field FW-IMVF_FG of the foreground image can be set to half of the intermediate motion vector field FW-IMVF_BG of the background image.

The first and second principles described above are expressed in a linear fashion as shown in the graph of FIG. The formula for obtaining the first slope L1 existing in the graph of FIG. 21 is expressed as follows. (For convenience, see FG <BG, MV <BG only.)

As shown in FIG. 22, the present invention for achieving the first example reduces only the size of the backward motion buffer used for backward motion compensation to reduce the size of the buffer while preserving the image quality (lowering image quality deterioration) . The size reduction of the backward motion buffer is determined within the range of values that the backward intermediate motion vector field (BW-IMVF) may have.

(First Condition) The area where no error occurs when reducing the size of the backward motion buffer follows the first slope (L1) considering at least one of the first principle and the second principle described above. (Second Condition) The area where the error occurs when reducing the size of the backward motion buffer follows a second slope L2 determined as a sufficiently low specific gravity w in consideration of the artifact occurrence.

The size of the area where the error occurs is determined as the area including the area (D) where the error does not occur + the artifact generation part (artifact generation area)?. The range of values that the buffer size reduction area, that is, the backward intermediate motion vector field (BW-IMVF), can have is determined by considering the first and second conditions, the intermediate motion vector field (IMVF_BG) Based on the intermediate motion vector field (IMVF_FG).

Expressions for obtaining the first slope L1 and the second slope L2 existing in the graph of FIG. 22 are expressed as follows. (For convenience, see FG <BG, MV <BG only.)

FIG. 23 is an exemplary view of a conventional forward motion compensation method, FIG. 24 is an exemplary view of a conventional backward motion compensation method, and FIG. 25 is an exemplary view of an optional motion compensation method according to an embodiment.

As shown in Figs. 23 and 24, the motion compensation method according to the prior art simply takes the forward motion compensation (FW) or the backward motion compensation (BW) method for the purpose of reducing the size of the buffer. As a result, according to the conventional art, deterioration brightness is maintained and displayed, so that image quality deterioration occurs even in the motion compensated image MCI or it becomes more apparent than before.

As shown in FIG. 25, the selective motion compensation method according to the embodiment includes an analysis of motion compensation, a relation between the foreground and background images, and a weight determination principle for selectively reflecting the motion compensation in order to effectively reduce the size of the buffer Taking into consideration at least one of forward motion compensation and backward motion compensation. As a result, degradation of image quality of the motion compensated image (MCI) is improved or the image becomes insensitive to the previous image because the deteriorated luminance is reduced according to the embodiment.

Hereinafter, an apparatus for constructing an embodiment of the present invention will be described.

FIG. 26 is a first exemplary view showing a part of a configuration of a display device according to an embodiment of the present invention, FIG. 27 is a second exemplary view showing a part of a configuration of a display device according to an embodiment of the present invention, 30 are diagrams for illustratively showing differences between the conventional method and the exemplary method.

26 and 27, a display device according to an embodiment of the present invention includes an image processing unit 110, a MEMC processing unit 160, and a timing control unit 120. [ The MEMC processing unit 160 receives data signals from the image processing unit 110, increases the frame rate for the data signals, and inserts new frames between the frames.

26, the MEMC processing unit 160 may be configured as an independent apparatus between the image processing unit 110 and the timing control unit 120 or may be configured inside the timing control unit 120 as shown in FIG. However, this is only an example, and the MEMC processing unit 160 may be configured inside the image processing unit 110. [

As described above, the present invention has an effect of predicting an error that may occur due to the reduction in size of a buffer during image processing and minimizing artifacts that may occur in an actual image. Further, since the present invention is based on a buffer size increase and reduction factor analysis technique, the image quality can be improved while reducing the size of the buffer.

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 processor 120: timing controller
130: Data driver 140:
150: display panel 160: MEMC processor

Claims (10)

A compensation frame is generated between the Nth frame and the (N + 1) th frame, and a motion compensated image is formed in the compensation frame based on the first image in the Nth frame and the second image in the (N + 1) In the image processing method,
Analyzing characteristics of the first image and the second image to analyze the presence or absence of a background image and a foreground image;
Defining an artifact generation area according to presence or absence of the background image and the foreground image; And
And selecting at least one of a forward motion compensation using the first image and a backward motion compensation using the second image in consideration of the artifact generation area. The method according to claim 1,
In the step of selecting the compensation scheme
And selecting a compensation scheme and varying the size of the buffer memory required for the forward motion compensation and the backward motion compensation. 3. The method of claim 2,
In the step of selecting the compensation scheme
Wherein the size of one of the forward motion buffer for the forward motion compensation and the backward motion buffer for the backward motion compensation is reduced. The method of claim 3,
The range for reducing the size of one of the forward motion buffer and the backward motion buffer is
And an intermediate motion vector field corresponding to a set of motion vectors obtained by scaling the size of the compensation frame. 5. The method of claim 4,
The intermediate motion vector field
A forward intermediate motion vector field of the foreground image,
A forward intermediate motion vector field of the background image,
A backward intermediate motion vector field of the foreground image,
And a backward intermediate motion vector field of the background image. 5. The method of claim 4,
Wherein reducing the size of one of the forward motion buffer and the backward motion buffer comprises:
Consider an area where an error does not occur and an area where an error occurs,
Wherein the size of the area where the error occurs is determined as a sum of the area where the error does not occur and the artifact generation area. The method according to claim 6,
The area where the error occurs is
Wherein the size of the motion buffer is reduced with a low specific gravity in consideration of the artifact occurrence. A compensation frame is generated between the Nth frame and the (N + 1) th frame, and a motion compensated image is formed in the compensation frame based on the first image in the Nth frame and the second image in the (N + 1) A MEMC processing unit; And
And a display panel for displaying an image based on the image output from the MEMC processing unit,
The MEMC processing unit
Analyzing characteristics of the first image and the second image to analyze presence / absence of a background image and a foreground image, defining an artifact generation area according to presence or absence of the background image and the foreground image, And compensating for at least one of a forward motion compensation using the first image and a backward motion compensation using the second image. 9. The method of claim 8,
The MEMC processing unit
Wherein at least one of the forward motion compensation and the backward motion compensation is selected and the size of the buffer memory required for the forward motion compensation and the backward motion compensation is different. 10. The method of claim 9,
By the operation of the MEMC processing unit
Wherein the size of one of the forward motion buffer for the forward motion compensation and the backward motion buffer for the backward motion compensation is reduced.

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