KR20120042165A - Image processing circuit and display device using the same - Google Patents

Abstract

PURPOSE: An image processing circuit and a display apparatus using the same are provided to output a changed image when an original image is changed. CONSTITUTION: A moving average controller(10) activates an image change signal. The moving average controller generates first and second moving average control values. The moving average controller changes the second moving average control value when an image of n-th frame data is changed. A first image processing module(30) creates the n-th frame data. A second image processing module(40) converts a representative value of the n-th frame data.

Description

Image processing circuit and display device using the same {IMAGE PROCESSING CIRCUIT AND DISPLAY DEVICE USING THE SAME}

The present invention relates to an image processing circuit and a display device using the same.

As the information society develops, the demand for a display device for displaying an image is increasing in various forms. Recently, a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode are being developed. Various flat panel display devices such as organic light emitting diodes (OLEDs) are utilized.

Among image processing circuits of such display devices, a method of using a moving average filter that analyzes brightness and color difference information of a frame and prevents a sudden change of an image is known. By using the moving average filter, it is possible to prevent a sudden change in the image, and to improve flicker and the like. However, if the moving average filter is used in the case of a transition, the effect of the scene transition cannot be obtained, and therefore, the moving average filter is not used in the transition. Therefore, the moving average filter receives a scene change signal during scene change and outputs the input image as it is, thereby preventing side effects that may occur due to the moving average filter during scene change. However, since the moving average filter processes the image based on the information of the previous frame, when the image processing module including the moving average filter is continuously used, the scene change cannot be reflected even if the original image is changed. Occurs.

The present invention provides an image processing circuit capable of outputting a scene converted image and a display device using the same when a scene change occurs in the original image even when the image processing module including the moving average filter is continuously used.

The image processing circuit of the present invention activates a scene change signal for instructing scene change of the n-th frame data by comparing and analyzing the n-1 (n is a natural number) frame data and at least one or more previously input frame data, A moving average control unit for generating first and second moving average control values and changing the second moving average control values when changing scenes of the n-th frame data; A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And converting the representative value of the nth frame data input from the first image processing module by substituting the changed second moving average control value when the activated scene change signal is generated into an infinite impulse response variable. And a second image processing module for generating +1 frame data.

In addition, the image processing circuit of the present invention activates a scene change signal for instructing scene change of the n-th frame data by comparing and analyzing the n-1 (n is a natural number) frame data and at least one or more previously input frame data. A moving average control unit for generating first and second moving average control values and changing the second moving average control values when the scene change of the n-th frame data is performed; A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And converting the representative value of the n-th frame data input from the first image processing module by substituting the second moving average control value changed when the activated scene change signal is generated into a finite impulse response variable. And a second image processing module for generating +1 frame data.

The display device of the present invention comprises a display panel for displaying an image; A display panel driver which drives the display panel; A controller configured to generate timing control signals for controlling the display panel driver; An external system for supplying timing signals to the controller; And an image processing circuit for processing an image input from the external system and supplying the image to the controller, wherein the image processing circuit includes n-th (n is a natural number) frame data and at least one or more frames previously inputted thereto. Compare and analyze the data to activate a scene change signal indicating a scene change of the n-th frame data, generate first and second moving average control values, and convert the second moving average control value to the scene of the n-th frame data. A moving average control unit changing at the time of switching; A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And converting the representative value of the nth frame data input from the first image processing module by substituting the changed second moving average control value when the activated scene change signal is generated into an infinite impulse response variable. And a second image processing module for generating +1 frame data.

The display device of the present invention comprises a display panel for displaying an image; A display panel driver which drives the display panel; A controller configured to generate timing control signals for controlling the display panel driver; An external system for supplying timing signals to the controller; And an image processing circuit for processing an image input from the external system and supplying the image to the controller, wherein the image processing circuit includes n-th (n is a natural number) frame data and at least one or more frames previously inputted thereto. Compare and analyze the data to activate a scene change signal indicating a scene change of the n-th frame data, generate first and second moving average control values, and convert the second moving average control value to the scene of the n-th frame data. A moving average control unit changing at the time of switching; A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And converting the representative value of the n-th frame data input from the first image processing module by substituting the second moving average control value changed when the activated scene change signal is generated into a finite impulse response variable. And a second image processing module for generating +1 frame data.

According to an embodiment of the present invention, when an activated scene change signal is generated, the first image processing module bypasses the n-th frame data, and the second image converts the n-th frame data by changing an input moving average control value. It includes a processing module. As a result, according to the present invention, even when the image processing module including the moving average filter is continuously used, when the scene change occurs in the original image, the scene changed image may be output.

1 is a block diagram illustrating an image processing circuit including a moving average filter.
2 is a flowchart illustrating an image processing method of the image processing circuit of FIG. 1.
3 is a block diagram illustrating a continuous structure of an image processing module including a moving average filter.
4 is a block diagram illustrating an image processing circuit according to an exemplary embodiment of the present invention.
5A and 5B are flowcharts illustrating an image processing method of an image processing circuit according to an exemplary embodiment of the present invention.
6 is a graph showing a moving average ratio of the first moving average control value according to the first embodiment of the present invention.
7 is a graph showing a moving average ratio of the second moving average control value according to the first embodiment of the present invention.
8 is a graph showing a moving average ratio of the first moving average control value according to the second embodiment of the present invention.
9 is a graph showing a moving average ratio of the second moving average control value according to the second embodiment of the present invention.
10 is a block diagram illustrating a display device including an image processing circuit of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like numbers refer to like elements throughout. In the following description, when it is determined that a detailed description of known functions or configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The names of the components used in the following description are selected in consideration of the ease of preparation of the specification, and may be different from the names of the actual products.

1 is a block diagram illustrating an image processing circuit including a moving average filter. 2 is a flowchart illustrating an image processing method of the image processing circuit of FIG. 1. 1 and 2, the image processing circuit 400 includes a moving average controller 10 and an image processing module 20. The image processing module 20 includes a frame information calculator 21, a moving average filter 22, and an image converter 23. The moving average control unit 10 outputs a moving average control value Vmac to the moving average filter 22. In addition, the moving average control unit 10 compares n-1 (n is a natural number) frame data with at least one or more previously inputted frame data to instruct a scene change signal of the nth frame data (scene_change). ) When a scene change occurs in the n-1th frame period in the original image RGB, the scene change signal scene_change is activated in the nth frame period.

Hereinafter, the image processing method of the image processing circuit of FIG. 2 will be described in detail with reference to FIG. 1. First, the original image RGB is input to the frame information calculator 21. The frame information calculator 21 calculates a representative value of the n-th frame data by analyzing the data input in the n-th frame period in units of frames. The frame information calculator 21 may calculate a luminance average value, a luminance minimum value, a luminance maximum value, and the like based on the luminance information Y of the original image RGB as the representative value of the nth frame data. The frame information calculator 21 may calculate a color difference average of the original image RGB of the n−1th frame based on the color difference information CbCr as the representative value of the nth frame data. The frame information calculator 21 outputs the representative value of the nth frame data to the moving average filter 22. (S101)

The moving average filter 22 receives a scene change signal scene_change from the moving average control unit 10. When an activated scene change signal (scene_change) is input to the moving average filter 22, the moving average filter 22 bypasses the representative value of the n-th frame data input from the frame information calculator 21. do. When the deactivated scene change signal scene_change is input to the moving average filter 22, the moving average filter 22 receives the n-th frame data input from the frame information calculator 21 according to the moving average control value Vmac. The representative value of is converted and output to the image converter 23.

The moving average filter 22 may be implemented as an infinite impulse response filter (hereinafter referred to as "IIR filter"), or a finite impulse response filter (hereinafter referred to as "FIR filter"). . First, when the moving average filter 22 is implemented as an IIR filter, if the deactivated scene change signal (scene_change) is input to the moving average filter 22, the moving average filter 22 is moved from the frame information calculating unit 21. The representative value of the input n-th frame data is substituted into an infinite impulse response equation to perform operation. The infinite impulse response equation is shown in Equation 1.

In Equation 1, Output (n) is a representative value of the nth frame data currently output from the moving average filter 22, and Output (n-1) is n-1-1 previously output from the moving average filter 22. A representative value of the frame data, Input (n), represents a representative value of the nth frame data currently input to the moving average filter 22, and Vmac denotes a moving average control value that is an infinite impulse response variable.

In Equation 1, the moving average control value Vmac has a value between 0 and 1, and as the moving average control value Vmac increases, the representative value of the n-th frame data currently input to the moving average filter 22 is increased. Highly reflected in the calculation result.

Secondly, if the moving average filter 22 is implemented as a FIR filter, if no scene change signal (scene_change) is input, the moving average filter 22 uses the finite impulse to input the value inputted from the frame calculator 21. Perform the operation by substituting the reaction equation. The finite impulse response equation is shown in equation (2).

In Equation 2, Output (n) represents a representative value of the nth frame data currently output from the moving average filter 22, and Input (nx) represents a representative value of the nx frame data input to the moving average filter 22. , Vmac means the moving average control value which is a finite impulse response variable.

In Equation 2, the moving average control value Vmac is a positive integer equal to or greater than 0, and as the moving average control value Vmac is smaller, the representative value of the n-th frame data currently input to the moving average filter 22 is calculated. Is highly reflected in the results.

The moving average control value Vmac depends on whether the moving average filter 22 is implemented as an IIR filter or an FIR filter. In addition, the moving average control value Vmac varies depending on which value, such as the luminance average, the minimum luminance value, the maximum luminance value, or the color difference average, is calculated by the frame information calculator 21 as a representative value. The moving average control value Vmac may be determined through a preliminary experiment. (S102 to S104)

The image converter 23 processes the image based on the representative value output from the moving average filter 22 and outputs the image to the controller of the display device. When the activated scene change signal scene_change is input to the moving average filter 22, the image RGB ′ output from the image conversion unit 23 is the original image RGB input to the frame information calculation unit 21. Is the same as When the deactivated scene change signal scene_change is input to the moving average filter 22, the image RGB ′ output from the image conversion unit 23 is the original image RGB input to the frame information calculator 21. Is different. (S105 and S106)

3 is a block diagram illustrating a continuous structure of an image processing module including a moving average filter. Referring to FIG. 3, the image processing circuit 400 includes a moving average controller 10 and first to third image processing modules 30, 40, and 50. The first image processing module 30 includes a first frame information calculating unit 31, a first moving average filter 32, and a first image converting unit 33. And a second frame information calculator 41, a second moving average filter 42, and a second image converter 43. The third image processing module 50 includes a third frame information calculator 51, And a third moving average filter 52 and a third image converter 53.

The scene change signal (scene_change) output from the moving average control unit 10 is input to each of the first to third moving average filters 32, 42, and 52. In addition, the moving average control value Vmac output from the moving average control unit 10 is input to each of the first to third moving average filters 32, 42, and 52. The structure and image processing method of each of the first to third image processing modules 30, 40, and 50 are the same as those of the image processing module 20 described with reference to FIGS. 1 and 2.

In FIG. 3, the first image processing module 30 analyzes the data input in the n-th frame period in frame units to calculate the representative value of the n-th frame data, and calculates the representative value of the calculated n-th frame data. It selectively converts the output to the second image processing module 40. The second image processing module 40 analyzes the data input in the n-th frame period in units of frames, calculates the representative value of the n-th frame data, and selectively converts the calculated representative value of the n-th frame data to the third image. Output to the image processing module 50. The third image processing module 50 analyzes the data input in the n + 1th frame period in units of frames, calculates the representative value of the nth frame data, and selectively converts the representative value of the calculated nth frame data. Output

When a scene change occurs in the n-1th frame period in the original image RGB, the scene change signal scene_change is activated in the nth frame period. The scene change signal scene_change is activated in the nth frame period, but the scene input is input to the first image processing module 30 in the nth frame period. In addition, the image input to the second image processing module 40 is a scene change occurs in the n + 1 frame period, the image input to the third image processing module 50 is a scene change in the n + 2 frame period. This happens. Therefore, in the second moving average filter 42 of the second image processing module 40, the scene change signal scene_change is activated in the nth frame period, but the scene change occurs in the n + 1 frame period, so the scene The transition signal scene_change is not activated in synchronization with the scene transition. In the third moving average filter 52 of the third image processing module 50, the scene change signal scene_change is activated in the nth frame period, but the scene change signal occurs in the n + 2th frame period, so the scene change signal (scene_change) is not active in sync with the scene change.

In summary, in the image processing circuit 400 as shown in FIG. 3, the second and third image processing modules 40 and 50 except for the first image processing module 30 may have a scene change signal (scene_change). It is not activated in synchronization with. Accordingly, since the second moving average filter 42 of the second image processing module 40 does not receive a scene change signal (scene_change) when changing scenes, the second moving average filter 42 converts a value input from the second frame information calculating unit 41. There is a problem that the output to the second image converter 43. The third image processing module 50 also has the same problem as the second image processing module 40. Therefore, the image processing circuit 400 as shown in FIG. 3 has a problem in that even when the original image RGB is scene changed, the image which is scene changed can not be output. Hereinafter, an image processing circuit 400 including image processing modules including a moving average filter for outputting a scene converted image when the original image RGB is scene changed will be described.

4 is a block diagram illustrating an image processing circuit according to an exemplary embodiment of the present invention. Referring to FIG. 4, an image processing circuit according to an embodiment of the present invention includes a moving average controller 10 and first to third image processing modules 30, 40, and 50. The first image processing module 30 includes a first frame information calculating unit 31, a first moving average filter 32, and a first image converting unit 33. And a second frame information calculator 41, a second moving average filter 42, and a second image converter 43. The third image processing module 50 includes a third frame information calculator 51, And a third moving average filter 52 and a third image converter 53.

The scene change signal generated from the moving average control unit 10 is input to the first moving average filter 32. The moving average control unit 40 outputs the first moving average control value Vmac1 to the first moving average filter 32, and outputs the second moving average control value Vmac2 to the second moving average filter 42. 3 outputs to the moving average filter 52. When the activated scene change signal scene_change is generated, the second moving average control value Vmac2 changes. This will be described later with reference to FIGS. 6 and 7.

Although the image processing circuit 400 of the present invention exemplifies the first to third image processing modules 30, 40, and 50, the first to m th m may be implemented as an image processing module. Hereinafter, the image processing method of the image processing circuit 400 according to an embodiment of the present invention will be described in detail with reference to FIGS. 5A and 5B.

5A and 5B are flowcharts illustrating an image processing method of an image processing circuit according to a first embodiment of the present invention. 6 is a graph showing a moving average ratio of the first moving average control value according to the first embodiment of the present invention. 7 is a graph showing a moving average ratio of the second moving average control value according to the first embodiment of the present invention. The first embodiment of the present invention illustrates a case where the moving average filter is implemented as an IIR filter.

First, the original image RGB is input to the first frame information calculator 31 of the first image processing module 30. The first frame information calculator 31 calculates a first representative value of the n-th frame data by analyzing the data input in the n-th frame period in units of frames. The first frame information calculator 31 may calculate the luminance average value, the luminance minimum value, the luminance maximum value, and the like of the nth frame data based on the luminance information Y as the first representative value of the nth frame data. The first frame information calculator 31 may calculate a color difference average of the n-th frame data based on the color difference information CbCr as the first representative value of the n-th frame data. The first frame information calculator 31 outputs the first representative value of the n-th frame data to the first moving average filter 32. (S201)

The first moving average filter 32 receives a scene change signal scene_change from the moving average controller 10. When an activated scene change signal (scene_change) is input to the first moving average filter 32, the first moving average filter 32 may include a first of n-th frame data input from the first frame information calculator 31. Bypass the representative value. When the deactivated scene change signal (scene_change) is input to the first moving average filter 32, the first moving average filter 32 generates the first frame information calculator 31 according to the first moving average control value Vmac1. The first representative value of the n-th frame data inputted from) is converted and outputted to the first image converter 33.

Since the first moving average filter 32 is implemented as an IIR filter, if an inactive scene change signal (scene_change) is input to the first moving average filter 32, the first moving average filter 32 calculates the first frame information. The first representative value of the n-th frame data input from the unit 21 is substituted into Equation 1, which is an infinite impulse response equation, to perform calculation. In this case, the first moving average control value Vmac1 is input to Equation 1 instead of the moving average control value Vmac.

Referring to FIG. 6, the x-axis of the graph of FIG. 6 represents a time and the y-axis represents a first moving average control value Vmac1, and the graph of FIG. 6 represents a first moving average control value Vmac1 over time. Shows. The first moving average control value Vmac1 has a constant value regardless of the activated scene change signal scene_change and the deactivated scene change signal scene_change. In the case of FIG. 6, the first moving average control value Vmac1 has a minimum value.

The first moving average control value Vmac1 depends on whether the first moving average filter 32 is implemented as an IIR filter or an FIR filter. In addition, the first moving average control value Vmac varies depending on which value, such as the luminance average, the minimum luminance value, the maximum luminance value, or the color difference average, is calculated by the first frame information calculator 31 as a representative value. The first moving average control value Vmac may be determined through a preliminary experiment. (S202 to S204)

The first image converter 33 processes the image based on the first representative value output from the first moving average filter 32 and outputs the image to the controller of the display device. When the activated scene change signal scene_change is input to the first moving average filter 32, the image RGB ′ output from the first image conversion unit 33 is input to the first frame information calculator 31. Is the same as the original image (RGB). When the deactivated scene change signal scene_change is input to the first moving average filter 32, the image RGB ′ output from the first image conversion unit 33 is input to the first frame information calculator 31. Is different from the original image file (RGB). (S205)

The image output from the first image converter 33 is input to the second frame information calculator 41 of the second image processing module 40. The second frame information calculator 41 calculates a second representative value of the nth frame data by analyzing the data input in the nth frame period in units of frames. The second frame information calculator 41 may calculate the luminance average value, the luminance minimum value, the luminance maximum value, and the like of the nth frame data based on the luminance information Y as the second representative value of the nth frame data. The second frame information calculator 41 may calculate a color difference average of the n-th frame data based on the color difference information CbCr as the second representative value of the n-th frame data. The second frame information calculator 41 outputs the second representative value of the n-th frame data to the second moving average filter 42. (S206)

The second moving average filter 42 receives a second moving average control value Vmac2 from the moving average controller 10. When the activated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 higher than the first moving average control value Vmac1. When the deactivated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 which is the same as the first moving average control value Vmac1.

Since the first moving average filter 32 is implemented as an IIR filter, the second moving average filter 42 calculates an infinite impulse response operation of the second representative value of the nth frame data input from the second frame information calculating unit 41. The operation is performed by substituting the equation (1). In this case, the second moving average control value Vmac2 is input to Equation 1 instead of the moving average control value Vmac.

Referring to FIG. 7, the x-axis of the graph of FIG. 7 represents a time and the y-axis represents a second moving average control value Vmac2, and the graph of FIG. 7 represents a second moving average control value Vmac2 over time. Shows. When the inactive scene change signal scene_change occurs, the second moving average control value Vmac2 has a minimum value. When the activated scene change signal scene_change occurs, the second moving average control value Vmac2 has a maximum value. When the activated scene change signal scene_change occurs, the second moving average control value Vmac2 maintains the maximum value for a predetermined w1 time. After the predetermined w1 time elapses, the second moving average control value Vmac2 is gradually lowered from the maximum value to the minimum value for the predetermined w2 time.

In the IIR filter, the larger the second moving average control value Vmac2 is, the higher the representative value of the nth frame data currently input to the second moving average filter 42 is reflected in the calculation result. Since the second moving average control value Vmac2 has a maximum value for a predetermined w1 time, a scene change is reflected in the image output from the second image processing module.

The second moving average control value Vmac2 depends on whether the second moving average filter 42 is implemented as an IIR filter or an FIR filter. In addition, the second moving average control value Vmac varies depending on which value, such as the luminance average, the minimum luminance value, the maximum luminance value, or the color difference average, is calculated by the second frame information calculator 41 as a representative value. The second moving average control value Vmac2 may be determined through a preliminary experiment.

The predetermined time w1 and w2 depend on which of the IIR filter and the FIR filter is implemented by the second moving average filter 42. The predetermined times w1 and w2 are different depending on which value, such as luminance average, minimum luminance value, maximum luminance value, or color difference average, is calculated by the second frame information calculator 41 as a representative value of the n-th frame image. The predetermined time w1 and w2 may be determined through a preliminary experiment. (S207 to S209)

The second image converter 43 processes the image based on the second representative value output from the second moving average filter 42 and outputs the image to the controller of the display device. (S210)

The image output from the second image converter 43 is input to the third frame information calculator 51 of the third image processing module 50. The third frame information calculator 51 calculates a third representative value of the nth frame data by analyzing the data input in the n + 1th frame period on a frame basis. The third frame information calculator 51 may calculate the luminance average value, the luminance minimum value, the luminance maximum value, and the like of the nth frame data based on the luminance information Y as the third representative value of the nth frame data. The third frame information calculator 51 may calculate a color difference average of the n-th frame data based on the color difference information CbCr as the third representative value of the n-th frame data. The third frame information calculator 51 outputs the third representative value of the nth frame data to the third moving average filter 52. (S211)

The third moving average filter 52 receives a second moving average control value Vmac3 from the moving average controller 10. When the activated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 higher than the first moving average control value Vmac1. When the deactivated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 which is the same as the first moving average control value Vmac1. This is the same as described in steps S207 to S209. (S212 to S214)

The third image converter 53 processes the image based on the third representative value output from the third moving average filter 52 and outputs the image to the controller of the display device. (S215, S216)

8 is a graph showing a moving average ratio of the first moving average control value according to the second embodiment of the present invention. 9 is a graph showing a moving average ratio of the second moving average control value according to the second embodiment of the present invention. The second embodiment of the present invention illustrates a case where the moving average filter is implemented as an FIR filter. 5A and 5B, an image processing method of an image processing circuit according to a second embodiment of the present invention will be described.

First, the original image RGB is input to the first frame information calculator 31 of the first image processing module 30. The first frame information calculator 31 calculates a first representative value of the n-th frame data by analyzing the data input in the n-th frame period in units of frames. The first frame information calculator 31 may calculate the luminance average value, the luminance minimum value, the luminance maximum value, and the like of the nth frame data based on the luminance information Y as the first representative value of the nth frame data. The first frame information calculator 31 may calculate a color difference average of the n-th frame data based on the color difference information CbCr as the first representative value of the n-th frame data. The first frame information calculator 31 outputs the first representative value of the n-th frame data to the first moving average filter 32. (S201)

The first moving average filter 32 receives a scene change signal scene_change from the moving average controller 10. When an activated scene change signal (scene_change) is input to the first moving average filter 32, the first moving average filter 32 may include a first of n-th frame data input from the first frame information calculator 31. Bypass the representative value. When the deactivated scene change signal (scene_change) is input to the first moving average filter 32, the first moving average filter 32 generates the first frame information calculator 31 according to the first moving average control value Vmac1. The first representative value of the n-th frame data inputted from) is converted and outputted to the first image converter 33.

Since the first moving average filter 32 is implemented as an FIR filter, if an inactive scene change signal (scene_change) is input to the first moving average filter 32, the first moving average filter 32 calculates the first frame information. The first representative value of the n-th frame data input from the unit 21 is substituted into Equation 2, which is a finite impulse response equation, to perform calculation. In this case, the first moving average control value Vmac1 is input to Equation 2 instead of the moving average control value Vmac.

Referring to FIG. 8, the x-axis of the graph of FIG. 8 represents time and the y-axis represents the first moving average control value Vmac1, and the graph of FIG. 8 shows the first moving average control value Vmac1 over time. . The first moving average control value Vmac1 has a constant value regardless of the activated scene change signal scene_change and the deactivated scene change signal scene_change. In the case of FIG. 8, the first moving average control value Vmac1 has a maximum value.

The first moving average control value Vmac1 depends on whether the first moving average filter 32 is implemented as an IIR filter or an FIR filter. In addition, the first moving average control value Vmac varies depending on which value, such as the luminance average, the minimum luminance value, the maximum luminance value, or the color difference average, is calculated by the first frame information calculator 31 as a representative value. The first moving average control value Vmac1 may be determined through a preliminary experiment. (S202 to S204)

The first image converter 33 processes the image based on the first representative value output from the first moving average filter 32 and outputs the image to the controller of the display device. When the activated scene change signal scene_change is input to the first moving average filter 32, the image RGB ′ output from the first image conversion unit 33 is input to the first frame information calculator 31. Is the same as the original image (RGB). When the deactivated scene change signal scene_change is input to the first moving average filter 32, the image RGB ′ output from the first image conversion unit 33 is input to the first frame information calculator 31. Is different from the original image file (RGB). (S205)

The image output from the first image converter 33 is input to the second frame information calculator 41 of the second image processing module 40. The second frame information calculator 41 calculates a second representative value of the nth frame data by analyzing the data input in the nth frame period in units of frames. The second frame information calculator 41 may calculate the luminance average value, the luminance minimum value, the luminance maximum value, and the like of the nth frame data based on the luminance information Y as the second representative value of the nth frame data. The second frame information calculator 41 may calculate a color difference average of the n-th frame data based on the color difference information CbCr as the second representative value of the n-th frame data. The second frame information calculator 41 outputs the second representative value of the n-th frame data to the second moving average filter 42. (S206)

The second moving average filter 42 receives a second moving average control value Vmac2 from the moving average controller 10. When the activated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 lower than the first moving average control value Vmac1. When the deactivated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 which is the same as the first moving average control value Vmac1.

Since the first moving average filter 32 is implemented as an FIR filter, the second moving average filter 42 calculates a finite impulse response operation of the second representative value of the nth frame data input from the second frame information calculating unit 41. The operation is performed by substituting Equation (2). In this case, the second moving average control value Vmac2 is input to Equation 2 instead of the moving average control value Vmac.

Referring to FIG. 9, the x-axis of the graph of FIG. 9 represents a time and the y-axis represents a second moving average control value Vmac2, and the graph of FIG. 9 represents a second moving average control value Vmac2 over time. Shows. When the inactive scene change signal scene_change occurs, the second moving average control value Vmac2 has a maximum value. When the activated scene change signal scene_change occurs, the second moving average control value Vmac2 has a minimum value. When the activated scene change signal scene_change occurs, the second moving average control value Vmac2 maintains a minimum value for a predetermined w1 time. After the predetermined w1 time elapses, the second moving average control value Vmac2 is gradually lowered from the minimum value to the maximum value for the predetermined w2 time.

In the FIR filter, the smaller the second moving average control value Vmac2 is, the higher the second representative value of the n-th frame data currently input to the second moving average filter 42 is reflected in the calculation result. When the signal is generated, the second moving average control value Vmac2 has a minimum value (Min Value) for a predetermined w1 time so that the image output from the second image processing module is reflected in the scene change.

The second moving average control value Vmac2 depends on whether the second moving average filter 42 is implemented as an IIR filter or an FIR filter. In addition, the second moving average control value Vmac varies depending on which value, such as the luminance average, the minimum luminance value, the maximum luminance value, or the color difference average, is calculated by the second frame information calculator 41 as a representative value. The second moving average control value Vmac2 may be determined through a preliminary experiment.

The predetermined time w1 and w2 depend on which of the IIR filter and the FIR filter is implemented by the second moving average filter 42. The predetermined times w1 and w2 are different depending on which value, such as luminance average, minimum luminance value, maximum luminance value, or color difference average, is calculated by the second frame information calculator 41 as a representative value of the n-th frame image. The predetermined time w1 and w2 may be determined through a preliminary experiment. (S207 to S209)

The second image converter 43 processes the image based on the second representative value output from the second moving average filter 42 and outputs the image to the controller of the display device. (S210)

The image output from the second image converter 43 is input to the third frame information calculator 51 of the third image processing module 50. The third frame information calculator 51 calculates a third representative value of the nth frame data by analyzing the data input in the n + 1th frame period on a frame basis. The third frame information calculator 51 may calculate the luminance average value, the luminance minimum value, the luminance maximum value, and the like of the nth frame data based on the luminance information Y as the third representative value of the nth frame data. The third frame information calculator 51 may calculate a color difference average of the n-th frame data based on the color difference information CbCr as the third representative value of the n-th frame data. The third frame information calculator 51 outputs the third representative value of the nth frame data to the third moving average filter 52. (S211)

The third moving average filter 52 receives a second moving average control value Vmac3 from the moving average controller 10. When the activated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 lower than the first moving average control value Vmac1. When the deactivated scene change signal scene_change occurs, the moving average control unit 10 outputs a second moving average control value Vmac2 which is the same as the first moving average control value Vmac1. This is the same as described in steps S207 to S209. (S212 to S214)

The third image converter 53 processes the image based on the third representative value output from the third moving average filter 52 and outputs the image to the controller of the display device. (S215, S216)

10 is a block diagram illustrating a display device including an image processing circuit of the present invention. Referring to FIG. 10, the display device of the present invention includes a display panel 100, a display panel driver 200, a controller 300, an image processing circuit 400, and an external system 500. The display device of the present invention is a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting diode (Organic Light Emitting Diode) OLED) such as a flat panel display device.

The display panel 100 includes a lower substrate and an upper substrate. The liquid crystal layer is formed between the lower substrate and the upper substrate. A plurality of data lines and a plurality of gate lines cross each other on the lower substrate. The data lines and the gate lines are formed of metal lines. Liquid crystal cells are arranged in a matrix form on the display panel due to the cross structure of the data lines and the gate lines. In addition, a thin film transistor (TFT), a pixel electrode of a liquid crystal cell connected to the TFT, and a storage capacitor are formed on an upper surface of the lower substrate. The liquid crystal cells are driven by an electric field generated by the potential difference between the data voltage supplied to the pixel electrode through the data lines and the common voltage supplied to the common electrode to adjust the amount of light transmitted through the display panel.

A black matrix, a color filter, and a common electrode are formed on the lower surface of the upper substrate. The common electrode is formed on the lower surface of the upper substrate in a vertical electric field driving method such as twisted nematic (TN) mode and vertical alignment (VA) mode, and a horizontal electric field driving such as IPS (In Plane Switching) mode and FFS (Fringe Field Switching) mode. In the method, the upper surface of the lower substrate is formed together with the pixel electrode. A polarizing plate is attached to each of the lower substrate and the upper substrate, and an alignment film for setting the pretilt angle of the liquid crystal is formed on an inner surface of the lower substrate and the upper substrate.

The display device of the present invention includes a display panel driver 200 for driving the display panel 100 and a controller 300 for controlling the display panel driver 200. The display panel driver 200 includes a data driver and a gate driver. The data driver includes a plurality of source drive ICs. Many source drive ICs convert digital video data (RGB) into positive / negative analog data voltages using positive / negative gamma compensation voltages under the control of a timing controller and supply them to the data lines.

The gate driver comprises a plurality of gate drive integrated circuits each including a shift register, a level shifter for converting an output signal of the shift register into a swing width suitable for driving a TFT of a liquid crystal cell, an output buffer, and the like. The gate driver sequentially outputs a gate pulse (or scan pulse) having a pulse width of approximately one horizontal period under the control of the timing controller, and supplies the gate pulse to the gate lines.

The controller 300 includes a timing controller. The timing controller receives digital video data RGB ′ processed by the moving average filter from the image processing circuit 400 and receives timing signals from an external system 500 on which an external video source is mounted. The timing controller supplies digital video data RGB ′ received from the image processing circuit 400 to the data driver in accordance with the timing control signals. The timing signals include a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, a dot clock signal, and the like. The timing controller generates timing control signals for controlling the operation timing of the data driver and the gate driver based on timing signals from an external system. The image processing circuit 400 has been described in detail with reference to FIG. 4.

When the display device of the present invention is implemented with a liquid crystal display device, a backlight unit is required. The backlight unit may be implemented as a direct type backlight unit or an edge type backlight unit. In this case, it may include a backlight driver for driving the backlight unit.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

10: scene change detection unit 20: image processing module
21: frame information calculator 22: moving average filter
23: image conversion unit 30: the first image processing module
31: first frame information calculator 32: first moving average filter
33: first image conversion unit 40: second image processing module
41: second frame information calculator 42: second moving average filter
43: second image converting unit 50: third image processing module
51: third frame information calculator 52: third moving average filter
53: third image conversion unit 100: display panel
200: display panel driver 300: control unit
400: image processing circuit 500: external system

Claims (16)

N-1 (n is a natural number) frame data and at least one or more previously input frame data are compared and analyzed to activate a scene change signal indicating a scene change of the n-th frame data, and the first and second moving averages. A moving average control unit for generating control values and changing the second moving average control value at the time of scene change of the n-th frame data;
A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And
Second image processing for converting the representative value of the n-th frame data input from the first image processing module by substituting the second moving average control value changed when the activated scene change signal is generated into an infinite impulse response variable. An image processing circuit comprising a module. The method of claim 1,
And when the activated scene change signal is generated, the second moving average control value is input to the second image processing module at a value higher than the first moving average control value. The method of claim 1,
The first image processing module,
The image is characterized by generating the n-th frame data by converting a representative value of the n-th frame data by substituting the first moving average control value into the infinite impulse response variable in response to the deactivated scene change signal. Processing circuit. The method of claim 3, wherein
The second image processing module,
And generating the nth frame data by converting a representative value of the nth frame data by substituting a second moving average control value to the infinite impulse response variable when the deactivated scene change signal is generated. Processing circuit. The method of claim 4, wherein
And when the deactivated scene change signal is generated, the second moving average control value is input to the second image processing module at the same value as the first moving average control value. The method of claim 1,
The first image processing module,
A first frame information calculator configured to calculate data representative of the n-th frame data by analyzing data input in the n-th frame period in frame units;
A first moving average filter for selectively changing the representative value of the n-th frame data by substituting the representative value of the n-th frame data into an infinite impulse response equation; And
A first image conversion unit configured to transmit the n-th frame data to the second image processing module based on the representative value of the n-th frame data input from the first moving average filter,
The infinite impulse reaction equation,

Here, Output (n) represents a representative value of the nth frame data currently output from the first moving average filter, and Output (n-1) represents the n-1 frame data previously output from the first moving average filter. And a representative value, Input (n) is a representative value of the nth frame data currently input to the first moving average filter, and Vmac is the infinite impulse response variable. The method of claim 1,
The first image processing module,
A first frame information calculator configured to calculate data representative of the n-th frame data by analyzing data input in the n-th frame period in frame units;
A first moving average filter for changing the representative value of the n-th frame by substituting the representative value of the n-th frame data into an infinite impulse response equation; And
A first image conversion unit configured to transmit the n-th frame data to the second image processing module based on the representative value of the n-th frame data input from the first moving average filter,
The infinite impulse reaction equation,

Here, Output (n) represents a representative value of the nth frame data currently output from the first moving average filter, and Output (n-1) represents the n-1 frame data previously output from the first moving average filter. And a representative value, Input (n) is a representative value of the nth frame data currently input to the first moving average filter, and Vmac is the infinite impulse response variable. N-1 (n is a natural number) frame data and at least one or more previously input frame data are compared and analyzed to activate a scene change signal indicating a scene change of the n-th frame data, and the first and second moving averages. A moving average control unit for generating control values and changing the second moving average control value at the time of scene change of the n-th frame data;
A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And
Substituting the changed second moving average control value when the activated scene change signal is generated into a finite impulse response variable, the representative value of the n th frame data input from the first image processing module is converted to the n + An image processing circuit comprising a second image processing module for generating one frame data. The method of claim 8,
And the second moving average control value is input to the second image processing module at a value lower than the first moving average control value when the activated scene change signal is generated. The method of claim 8,
The first image processing module,
The image is characterized by generating the n-th frame data by converting the representative value of the n-th frame data by substituting the first moving average control value into the finite impulse response variable in response to the deactivated scene change signal. Processing circuit. The method of claim 10,
The second image processing module,
And generating the nth frame data by converting a representative value of the nth frame data by substituting a second moving average control value to the finite impulse response variable when the deactivated scene change signal is generated. Processing circuit. The method of claim 11,
And when the deactivated scene change signal is generated, the second moving average control value is input to the second image processing module at the same value as the first moving average control value. The method of claim 8,
The first image processing module,
A first frame information calculator configured to calculate data representative of the n-th frame data by analyzing data input in the n-th frame period in frame units;
A first moving average filter for selectively changing the representative value of the n-th frame data by substituting the representative value of the n-th frame data into a finite impulse response equation; And
A first image conversion unit configured to transmit the n-th frame data to the second image processing module based on the representative value of the n-th frame data input from the first moving average filter,
The finite impulse reaction equation,

Here, Output (n) represents a representative value of the nth frame data currently output from the first moving average filter, Input (nx) represents a representative value of the nx frame data input to the first moving average filter, and Vmac And the finite impulse response variable. The method of claim 8,
The first image processing module,
A first frame information calculator configured to calculate data representative of the n-th frame data by analyzing data input in the n-th frame period in frame units;
A first moving average filter for changing the representative value of the n-th frame by substituting the representative value of the n-th frame data into a finite impulse response equation; And
A first image conversion unit configured to transmit the n-th frame data to the second image processing module based on the representative value of the n-th frame data input from the first moving average filter,
The finite impulse reaction equation,

Here, Output (n) represents a representative value of the nth frame data currently output from the first moving average filter, Input (nx) represents a representative value of the nx frame data input to the first moving average filter, and Vmac And the finite impulse response variable. A display panel displaying an image;
A display panel driver which drives the display panel;
A controller configured to generate timing control signals for controlling the display panel driver;
An external system for supplying timing signals to the controller; And
An image processing circuit for processing an image input from the external system and supplying the image to the controller;
The image processing circuit,
N-1 (n is a natural number) frame data and at least one or more previously input frame data are compared and analyzed to activate a scene change signal indicating a scene change of the n-th frame data, and the first and second moving averages. A moving average control unit for generating control values and changing the second moving average control value at the time of scene change of the n-th frame data;
A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And
The second moving average control value, which is changed when the activated scene change signal is generated, is substituted into the infinite impulse response variable, thereby converting the representative value of the nth frame data input from the first image processing module to generate the n + And a second image processing module configured to generate one frame data. A display panel displaying an image;
A display panel driver which drives the display panel;
A controller configured to generate timing control signals for controlling the display panel driver;
An external system for supplying timing signals to the controller; And
An image processing circuit for processing an image input from the external system and supplying the image to the controller;
The image processing circuit,
N-1 (n is a natural number) frame data and at least one or more previously input frame data are compared and analyzed to activate a scene change signal indicating a scene change of the n-th frame data, and the first and second moving averages. A moving average control unit for generating control values and changing the second moving average control value at the time of scene change of the n-th frame data;
A first image processing module configured to generate the nth frame data by bypassing the nth frame data in response to the activated scene change signal; And
Substituting the changed second moving average control value when the activated scene change signal is generated into a finite impulse response variable, the representative value of the n th frame data input from the first image processing module is converted to the n + And a second image processing module configured to generate one frame data.

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