KR20070122092A - Motion blur reducing apparatus of flat display unit - Google Patents

Abstract

A motion blur reducing device of a flat display apparatus is provided to minimize a flickering effect and to reduce a motion blur effect by reducing a luminance difference between an even-numbered field and an odd-numbered field. A double frame conversion unit(21) converts a frequency of an input image signal to a twofold frequency. A low-pass filter(22A) is formed to filter an image signal of an even-numbered field. An unsharp masking unit(22B) performs an un-sharp masking process for an image signal of an odd-numbered field. A first compensator(24A) compensates an overflow or an underflow of a luminance level of the filtered image signal. A second compensator(24B) compensates an overflow or an underflow of a luminance level of the unsharp-masked image signal. A first multiplier(23A) is installed at an output terminal of the low-pass filter in order to apply a scaling parameter to the filtered image signal. A second multiplier(23B) is installed at an output terminal of the unsharp masking unit in order to apply the scaling parameter to the unsharp-masked image signal.

Description

Motion Blur Reduction Device for Flat Panel Display {MOTION BLUR REDUCING APPARATUS OF FLAT DISPLAY UNIT}

1 is a diagram illustrating insertion of black data for reducing motion blur according to the prior art.

2 is a block diagram of a motion blur reduction device of a flat panel display device according to the present invention;

3 (a)-(c) are exemplary diagrams illustrating filter coefficient setting of the low pass filter of FIG. 2;

4 is a detailed block diagram of an unsharp masking unit in FIG. 2;

5 is an exemplary diagram of luminance waveform diagrams and image outputs of FIG. 4.

FIG. 6A is an exemplary diagram of a low pass filtered image of FIG. 2. FIG.

FIG. 6B is an exemplary view of an unsharp masked image of FIG. 2. FIG.

Figure 6 (c) is an illustration showing that the motion blur is improved by the combination of (a), (b).

7 is a block diagram of another embodiment of a motion blur reduction apparatus of a flat panel display of the present invention.

*** Description of the symbols for the main parts of the drawings ***

21: double frame conversion unit 22A, 41: low pass filter

22B: Unsharp masking processing unit 23A, 23B: Multiplier

24A, 24B: Compensator 42: Subtractor

43: adder

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving a motion-blur phenomenon in a display device displaying an image. In particular, the present invention relates to a motion of a flat panel display device capable of improving a motion blur phenomenon without causing flicker on the entire screen. A blur reduction device.

In the process of acquiring the image, the motion-blur phenomenon caused by the shaking of the image capturing device or the subject is a major cause of greatly reducing the sharpness of the image.

Therefore, in the impulse driving method of the conventional flat panel display device, black data or gray data is regularly inserted into an image frame to prevent motion blur. FIG. 1 illustrates an example in which black data is continuously inserted into an image frame. will be.

However, when using such a method, the luminance difference of the entire screen to be displayed is increased, which causes a flicker phenomenon.

Accordingly, an object of the present invention is to provide a motion blur reduction device that suppresses the occurrence of motion blur and prevents flicker from occurring on the screen by this operation.

The present invention for achieving the above object, and a double frame conversion unit for converting the frequency of the input video signal doubling; A low pass filter for performing low pass filtering on the video signal of the even field output from the double frame converter, and an unsharp masking processing unit for unsharp masking the video signal of the odd field; A first compensator for compensating for an overflow or an underflow in which the luminance level of the low-pass filtered image signal exceeds a preset luminance level; And a second compensator configured to compensate for an overflow or an underflow in which the luminance level of the unsharp masked image signal exceeds a preset luminance level.

Another invention for achieving the above object is an RGB / YUV converter for converting an input video signal of the RGB format into a video signal of the YUV format; A low pass filter for low-pass filtering the luminance signal Y output from the RGB / YUV converter, and an unsharp masking unit for unsharp masking the luminance signal Y; A first YUV / RGB converter for converting the luminance signal Y output from the low-pass filter side and the color signals U and V output from the RGB / YUV converter into R, G and B color signals for even fields And a second to convert the luminance signal Y output from the unsharp masking processor side and the color signals U and V output from the RGB / YUV converter into R, G, and B color signals for odd field. It features a YUV / RGB converter.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram illustrating an embodiment of a motion blur reduction apparatus for a flat panel display according to an embodiment of the present invention. As shown in FIG. 2, a double signal converts a frequency of an input video signal into double and outputs an even field and an odd field. A frame converter 21; A low pass filter 22A for low-pass filtering each of the even-numbered video signals R, G, and B inputted from the double frame converter 21; A multiplier (23A) for multiplying the video signal output from the low pass filter (22A) by the scaling parameter (a); A compensator 24A that compensates for an overflow or an underflow in which the luminance level output from the multiplier 23A exceeds a preset luminance level (for example, 0 to 255); An unsharp masking processor 22B for unsharp masking video signals R, G, and B of odd field input from the double frame converter 21; A multiplier (23B) for multiplying the scaling parameter (b) by the video signal output from the unsharp masking processor (22B); The compensator 24B compensates for an overflow or an underflow in which the luminance level output from the multiplier 23B exceeds a predetermined luminance level (for example, 0 to 255). When described in detail with reference to Figures 3 to 6 attached to the operation of the present invention configured as described above are as follows.

First, the 60 HZ input image signal INPUT IMAGE is converted into a 120 HZ double frame by the double frame converter 21, and the even field video signal is provided to the low pass filter 22A. The video signal of the field (Odd field) is provided to an unsharp masking processor 22B.

In this case, the low pass filter 22A low-pass filters the video signals R, G, and B of the even field input from the double frame converter 21, respectively, and FIG. 3 illustrates an example of the low pass filtering. It is shown. That is, FIG. 3A illustrates an input image before low pass filtering, and FIG. 3B illustrates an example of low pass filtering using each pixel value as a weighted average of neighboring pixels. FIG. 3C illustrates an example in which the weight of the center pixel is set higher than the weight of the outer pixel and filtered.

The unsharp masking processor 22B unmasks the input image signal INPUT IMAGE, which will be described with reference to FIG. 4.

The luminance component of the input image signal INPUT IMAGE as shown in FIG. 5A is directly provided to one input terminal of the subtractor 42 and low-pass filtered through the low pass filter 41 on the other hand. It is converted to a smooth luminance component as shown in b) and then provided to the other input of the subtractor 42.

In addition, the subtractor 42 subtracts the luminance component filtered through the low pass filter 41 from the luminance component of the input image signal INPUT IMAGE, and outputs the luminance component as shown in FIG. do. That is, the low pass filter 41 and the subtractor 42 serve as components of the high pass filter HPF.

The adder 43 adds the output signal of the subtracter 42 to the input image signal INPUT IMAGE to emphasize the luminance component of the edge portion of the image as shown in FIG.

The video signal output from the low pass filter 22A is multiplied by the scaling parameter a in the multiplier 23A and then compensated in the compensator 24A. The compensation process refers to compensation for overflow or underflow in which the luminance level of the input image exceeds a preset luminance level (for example, 0 to 255).

Similarly, the video signal output from the unsharp masking processor 22B is multiplied by the constant b in the multiplier 23B and then compensated in the compensator 24B as described above.

That is, in the case of the luminance level of the image output from the low pass filter 22A and the unsharp masking processor 22B, values outside the range of 0 to 255 may be generated according to neighboring pixel values. LCD cannot be displayed, so it is necessary to compensate the output properly.

When the luminance level of the image output from the low pass filter 22A or the unsharp masking processor 22B exceeds 255, the compensator 24A or the compensator 24B is over-expressed using Equation 1 below. Compensate the flow.

Further, when the luminance level of the image output from the low pass filter 22A or the unsharp masking processor 22B is less than 0, the compensator 24A or the compensator 24B uses the following Equation 2 below. Compensate the flow.

As a result, the compensator 24A sequentially outputs the image of the even field as shown in FIG. As shown in (b) of FIG. 6, the unsharp masked image is sequentially output.

Accordingly, since the luminance of the edge portion is weakened and enhanced in the even and odd fields, respectively, motion blur is suppressed by the luminance difference of the edge portion, and thus the flicker does not occur because the amount of change in luminance between the fields is not large. It is possible to provide an image as shown in FIG.

Meanwhile, FIG. 7 shows another embodiment of the present invention. As shown in FIG. 7, an RGB / YUV converter 71 converts an input image signal of RGB format into an image signal of YUV format; A low pass filter 72A for low-pass filtering the luminance signal output from the RGB / YUV converter 71; A multiplier (73A) for multiplying the luminance signal output from the low pass filter (72A) by the scaling parameter (a); YUV / which converts the luminance signal Y_IMAGE output from the multiplier 73A and the color signals U_IMAGE and V_IMAGE output from the RGB / YUV converter 71 into R, G, and B color signals for even fields. An RGB converter 74A; An unsharp masking processor 72B for unsharp masking the luminance signal Y_IMAGE input from the RGB / YUV converter 71 so that an edge portion of the image is emphasized; A multiplier (73B) for multiplying the scaling parameter (b) by the luminance signal output from the unsharp masking processor (72B); A YUV / RGB converter for converting the luminance signal output from the multiplier 73B and the color signals U_IMAGE and V_IMAGE output from the RGB / YUV converter 71 into R, G, and B color signals for odd field. 74B), the operation of the second embodiment of the present invention configured as described above is as follows.

First, the input image signal INPUT IMAGE in the RGB format is converted into the image signal in the YUV format by the RGB / YUV converter 71, and the luminance signal Y_IMAGE is converted into the low pass filter 72A and the unsharp masking processor 72B. ), And the color signals U_IMAGE and V_IMAGE are directly transmitted to the YUV / RGB converter 74B at the output terminal.

In this case, the low pass filter 72A performs low pass filtering on the luminance signal Y_IMAGE input from the RGB / YUV converter 71 so that smooth luminance components are output from the low pass filter 72 as shown in FIG. The luminance component is multiplied by the scaling parameter a in the multiplier 73A.

In addition, the unsharp masking unit 72B performs an unsharp masking process on the luminance signal Y_IMAGE input from the RGB / YUV converter 71 as in the unsharp masking unit 22B of FIG. The luminance component of the edge portion of the image is emphasized and output, and the luminance component thus output is multiplied by the scaling parameter b in the multiplier 73B.

The YUV / RGB converter 74A converts the luminance signal output from the multiplier 73A and the color signals U_IMAGE and V_IMAGE output from the RGB / YUV converter 71 into R, G, and B color signals for even fields. To print.

Similarly, the YUV / RGB converter 74B converts the luminance signal output from the multiplier 73B and the color signals U_IMAGE and V_IMAGE output from the RGB / YUV converter 71 for odd-numbered fields R, G, and B. Converted to a color signal and output.

As a result, the YUV / RGB converter 74A sequentially outputs the low-field filtered even field images as shown in FIG. 6A, and the YUV / RGB converter 74B performs the unsharp masking process as described above. The image of the odd field as shown in FIG. 6 (b) is sequentially output.

Accordingly, since the luminance of the edge portion is weakened and enhanced in the even and odd fields, respectively, motion blur is suppressed by the luminance difference of the edge portion, and the flicker is not caused because the amount of luminance variation between the fields is not large. It is possible to provide an image as shown in (c).

As described in detail above, in the present invention, the even field is low-pass filtered and the odd field is unsharp masked, and the edge portion is highlighted. There is an effect that can reduce the blur phenomenon.

Claims (10)

A double frame converting unit converting the frequency of the input video signal twice; A low pass filter for performing low pass filtering on the video signal of the even field output from the double frame converter, and an unsharp masking processing unit for unsharp masking the video signal of the odd field; A first compensator for compensating for overflow or underflow of the luminance level of the low-pass filtered image signal; And a second compensator for compensating for overflow or underflow of the luminance level of the unsharp masked video signal. The apparatus of claim 1, further comprising: a first multiplier configured to apply a scaling parameter (a) to a low pass filtered image signal at an output of the low pass filter. The apparatus of claim 1, further comprising a second multiplier configured to apply a scaling parameter (b) to an unsharp masked video signal at an output of the unsharp masked processor. . The method of claim 1, wherein the unsharp masking processing unit A low pass filter for low pass filtering the luminance component of the input video signal; A subtractor for subtracting the luminance component filtered through the low pass filter from the luminance component of the input video signal; And an adder configured to add an output signal of the subtracter to the input image signal and output an image signal in which the luminance component of the edge portion of the image is emphasized. The apparatus of claim 1, wherein the luminance level of the video signal is 0 to 255 levels. The apparatus of claim 1, wherein the first compensator and the second compensator compensate for the overflow using the following Equation.

The apparatus of claim 1, wherein the first compensator and the second compensator compensate for the underflow by using the following Equation.

An RGB / YUV converter for converting an input video signal in RGB format into a video signal in YUV format; A low pass filter for low-pass filtering the converted luminance signal (Y), and an unsharp masking processing unit for unsharp masking the luminance signal (Y); A first YUV / RGB converter for converting the luminance signal Y output from the low-pass filter side and the color signals U and V output from the RGB / YUV converter into R, G and B color signals for even fields And a second to convert the luminance signal Y output from the unsharp masking processor side and the color signals U and V output from the RGB / YUV converter into R, G, and B color signals for odd field. A motion blur reduction device for a flat panel display comprising a YUV / RGB converter. 10. The apparatus of claim 8, further comprising a first multiplier for applying a scaling parameter (a) to a low pass filtered video signal at an output of the low pass filter. 10. The apparatus of claim 9, further comprising a second multiplier for applying a scaling parameter (b) to an unsharp masked video signal at an output of the unsharp masked processor. .

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