KR100667297B1 - Display device for decreasing noises of main image signal and sub image signal separately and method thereof - Google Patents

Abstract

A display device and a method for individually attenuating noises of a main video signal and a sub video signal are provided to detect the noises of the main video signal and the sub noise signal and individually perform a noise attenuation operation for the main video signal and the sub video signal to effectively remove the noises. A display device includes a first signal input unit(110) for receiving a main video signal, a second signal input unit(120) for receiving a sub video signal, a signal processor(130) for synthesizing the main video signal and the sub video signal to output a composite video signal, and a controller(140) for outputting a timing signal for selectively processing the main video signal and the sub video signal. The display device further includes a noise detector(150) for carrying out a noise detection operation for the composite video signal in response to the timing signal to individually detect noise included in the main video signal and noise included in the sub video signal, and a noise attenuator(160) for performing a noise attenuation operation for the composite video signal in response to the noise detected by the noise detector and the timing signal to individually attenuate the noise of the main video signal and the noise of the sub video signal.

Description

Display device for reducing noise of main video signal and sub video signal separately and method thereof {Display device for decreasing noises of main image signal and sub image signal separately and method

1A is a schematic diagram illustrating a screen displaying a main video signal and a sub video signal in a double window manner;

1B is a schematic diagram illustrating a screen displaying a main video signal and a sub video signal in a picture-in-picture manner;

2 is a block diagram illustrating a configuration of a display apparatus according to an exemplary embodiment.

3 is a block diagram illustrating an example of a configuration of a noise detector used in the display device of FIG. 2;

4 is a block diagram illustrating still another example of a configuration of a noise canceling unit used in the display apparatus of FIG. 2;

5 is a schematic diagram illustrating an example of a timing signal used in the display device of FIG. 2;

6 is a schematic diagram illustrating still another example of a timing signal used in the display apparatus of FIG. 2, and

7 is a flowchart illustrating a noise removing method according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawing

110: first signal input unit 120: second signal input unit

130: signal processing unit 140: control unit

150: noise detector 160: noise attenuator

The present invention relates to a display apparatus and method for attenuating noise included in an input video signal. More particularly, when a main video signal and a sub video signal are received, noise detection and detection are performed separately for each video signal. The present invention relates to a display apparatus and a method for performing attenuation.

In order to satisfy various needs of a user, a technology of displaying a plurality of video signals on the same screen has been applied to display devices for a long time.

1A and 1B are schematic diagrams showing an example of a method of simultaneously displaying a plurality of video signals on the same screen.

First, FIG. 1A illustrates a screen displaying a main video signal and a sub video signal in a double window manner. The double window method refers to a method of simultaneously displaying the main image 10 and the sub image 20 by dividing the screen into two as shown in FIG. 1A. The video signal for displaying the main image 10 and the sub image 20 may be a signal supplied from various sources such as a TV broadcast signal, a DVD playback signal, a VCR playback signal, or the like.

FIG. 1B is a schematic diagram illustrating a screen displaying a main video signal and a sub video signal in a picture-in-picture (PIP) method. As shown in FIG. 1B, the sub image 20 may be displayed as a small sub screen on one side of the screen edge.

On the other hand, noise applied to an image signal is a major cause of deterioration of image quality during image reproduction. Accordingly, in the display device, various techniques for reducing the noise applied to the image signal to improve the image quality of the reproduced image are applied. In this case, the operation of accurately detecting the amount of noise included in the video signal is preceded in order to reduce the noise. Accordingly, the degree of noise attenuation is determined according to the detected amount of noise.

On the other hand, in the conventional display device having a function of simultaneously displaying a plurality of video signals, the above-described noise detection operation and noise reduction operation is performed based on one video signal of the main video signal and the sub video signal. In this case, when the amount of noise reduction is determined by detecting the amount of noise on the basis of the main video signal, the noise reduction operation is performed to the same degree of noise reduction for the sub video signal. In this case, when the amount of noise of the sub video signal is larger than that of the main video signal, the noise attenuation of the sub video signal is not normally performed. In addition, when the amount of noise of the sub video signal is less than that of the main video signal, there is a problem that the sub image displayed by the sub video signal is blurred due to excessive noise attenuation.

In order to improve this problem, the noise detection module and the attenuation module should be provided separately for each source. In this case, the noise detection module and the attenuation module added cause a problem that the manufacturing cost of the display device increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to detect an amount of noise separately for a main video signal and a sub video signal, and then to detect the amount of noise for the main video signal and a sub video signal. The present invention provides a display apparatus and a method for effectively removing noise by individually performing noise reduction operations.

According to an aspect of the present invention, there is provided a display apparatus including a first signal input unit for receiving a main image signal, a second signal input unit for receiving a sub image signal, the main image signal, and the sub image. A signal processor for outputting a synthesized video signal obtained by synthesizing the signals, a controller for outputting a timing signal for selectively processing the main video signal and the sub video signal, and performing a noise detection operation on the synthesized video signal according to the timing signal A noise detector configured to separately detect an amount of noise included in each of the main image signal and the sub image signal, and a noise of the synthesized image signal according to the amount of noise detected from the noise detector and the timing signal Performing the attenuation operation so that the main video signal and the sub-zero It comprises with respect to each signal individually noise reduction part for attenuating the noise.

Preferably, the control unit is configured to process the processing section for the main video signal and the processing section for the sub video signal according to the main image position displayed by the main video signal and the sub image position displayed by the sub video signal. Can be determined.

In this case, the timing signal preferably includes a first pulse signal indicating a processing section for the main video signal and a second pulse signal indicating a processing section for the sub video signal.

More preferably, the noise detector provides the amount of noise detected from the synthesized video signal while the first pulse signal is applied from the controller as the main noise amount to the noise attenuation unit, and the second controller detects the second noise from the controller. The second noise amount detected from the composite video signal while the pulse signal is applied may be provided as the sub noise amount to the noise reduction unit.

The noise attenuator may attenuate the noise of the composite image signal to attenuation corresponding to the main noise amount when the first pulse signal is applied from the controller, and when the second pulse signal is applied from the controller, The noise of the composite video signal may be attenuated to an extent corresponding to the amount of noise.

On the other hand, the noise reduction method according to an embodiment of the present invention, (a) receiving a main video signal and a sub video signal, (b) outputs a composite video signal obtained by combining the main video signal and the sub video signal (C) generating a timing signal for selectively processing the main video signal and the sub video signal, (d) performing a noise detection operation on the composite video signal according to the timing signal, Separately detecting the amount of noise included in each of the main video signal and the sub video signal, and (e) performing a noise reduction operation on the synthesized video signal according to the individually detected noise amount and the timing signal. The method may further include attenuating noise separately for each of the main video signal and the sub video signal.

Preferably, in the step (c), the processing section for the main image signal and the sub image according to the main image display position displayed by the main video signal and the sub image display position displayed by the sub video signal. And determining a processing interval for the signal.

More preferably, the step (c) generates a timing signal including a first pulse signal indicating a processing interval for the main video signal and a second pulse signal indicating a processing interval for the sub video signal. Can be output.

Also preferably, the step (d) may include outputting an amount of noise detected from the composite video signal as a main noise amount while the first pulse signal is output, and while outputting the second pulse signal. And outputting an amount of noise detected from the composite video signal as a sub noise amount.

On the other hand, the step (e), attenuating the noise of the composite video signal to the degree of attenuation corresponding to the amount of main noise while the first pulse signal is output, and while the second pulse signal is output And attenuating the noise of the composite image signal to a degree of attenuation corresponding to the amount of sub-noise.

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

2 is a block diagram illustrating a configuration of a display apparatus according to an exemplary embodiment. The display apparatus according to FIG. 2 includes a first signal input unit 110, a second signal input unit 120, a signal processor 130, a controller 140, a noise detector 150, and a noise attenuator 160. .

The first signal input unit 110 serves to receive the main video signal. The second signal input unit 120 serves to receive the sub image signal. The main video signal and the sub video signal may be an external input signal such as a TV broadcast signal, a DVD playback signal, or a VCR playback signal. In order to receive the main image signal and the sub image signal, the first signal input unit 110 and the second signal input unit 120 may be implemented as a tuner or an external input interface.

The signal processor 130 synthesizes the signals received through the first signal input unit 110 and the second signal input unit 120 to generate a composite image signal. Specifically, the signal processor 130 may decode and scale the main video signal and the sub video signal, respectively, and then de-multiplex each scaled signal to generate a composite video signal.

The controller 140 generates a timing signal for separately processing the main video signal and the sub video signal. Specifically, the controller 140 checks the position of the sub image displayed by the sub image signal on the screen. The position of the sub image may be preset. That is, when the double window display function is activated, half of the screen becomes the sub image display position. When the PIP function is activated, one of the corner portions of the screen becomes the sub image display position. The controller 140 considers the main image to be displayed in the remaining screen areas except for the screen area occupied by the sub-image.

Accordingly, the controller 140 determines a signal section to be displayed on the region where the sub-image is located among the composite video signals as the sub video signal processing section and determines the other signal section as the main video signal processing section. Accordingly, a timing signal for displaying the main video signal processing section and the sub video signal processing section, respectively, is generated. The generated timing signal is provided to the noise detector 150 and the noise attenuator 160.

The noise detector 150 detects the noise included in the composite video signal according to the timing signal provided from the controller 140 to separately detect the amount of noise included in the main video signal and the amount of noise included in the sub video signal. Can be. Specifically, the noise detector 150 detects the amount of noise detected from the composite video signal input during the main video signal processing period as the amount of main noise included in the main video signal. On the other hand, the amount of noise detected from the composite video signal input during the sub video signal processing period is detected as the amount of sub noise included in the sub video signal. Accordingly, the detected main noise amount and the sub noise amount are provided to the noise attenuator 160.

3 is a block diagram illustrating an example of a configuration of a noise detector 150 used in the display apparatus of FIG. 2. The noise detector 150 according to FIG. 3 includes a calculator 151 and a switching unit 152.

The calculator 151 calculates the amount of noise included in the composite video signal. The amount of noise is usually expressed as a standard deviation, which is the variance value or the square root of the variance value. Since the noise calculation method is described in detail in Patent Application No. 10-2002-0079292, etc., which was previously filed under the name of the apparatus 'Measurement apparatus and method for measuring the noise of an image signal,' a detailed description thereof will be omitted.

The switching unit 152 is switched according to the timing signal provided from the control unit 140. That is, the switching unit 152 outputs the amount of noise calculated by the calculating unit 151 as the main noise amount to the noise attenuation unit 160 during the main image signal processing period, and the calculating unit 152 during the sub image signal processing period. The amount of noise calculated by is output to the noise attenuation unit 160 separately as a sub-noise amount.

Meanwhile, the noise attenuator 160 performs a noise attenuation operation on the composite image signal by referring to the timing signal provided from the controller 140 and the amount of noise provided from the noise detector 150. Specifically, the timing signal is checked to determine whether the main video signal processing section or the sub video signal processing section. In the case of the main video signal processing section, the noise reduction operation is performed to a degree corresponding to the amount of main noise provided from the noise detector 150. On the other hand, in the case of the sub image signal processing section, the noise reduction operation is performed to the degree of attenuation corresponding to the amount of sub noise. In this case, the attenuation degree may be determined according to the magnitude of the noise attenuation weight. That is, the noise attenuation operation may be attenuated by multiplying a weight value between 0 and 1 by an input pixel value.

4 is a block diagram illustrating an example of a configuration of the noise reduction unit 160 used in the display apparatus of FIG. 2. According to FIG. 4, the noise attenuator 160 includes a weight generator 161 and a noise processor 162.

The weight generator 161 generates a weight corresponding to the amount of noise provided from the noise detector 150. Specifically, a first weight corresponding to the main noise amount and a second weight corresponding to the sub noise amount are generated. In this case, each weight may be determined as a predetermined value between 0 and 1. The weight generator 161 may generate first and second weights using a database in which the amount of noise and the weight information corresponding thereto are recorded. Each generated weight is provided to the noise processor 162.

The noise processor 162 performs a noise reduction operation on the composite image signal by using the timing signal and each weight. That is, in the case of the main video signal processing section, the noise is attenuated by applying a first weight, and in the case of the sub video signal processing section, the noise is reduced by applying the second weight.

5 is a schematic diagram illustrating an example of a timing signal configuration output from the controller 140. According to FIG. 5, the timing signal is implemented as one signal including a high pulse period and a low pulse period. The high pulse section refers to the main video signal processing section and the low pulse section refers to the processing section of the sub video signal. As shown in FIG. 5, when the main image 10 and the sub image 20 are displayed in a double window manner, the timing signal may be implemented in a form in which the high pulse interval and the low pulse interval are alternately repeated at the same interval. Can be.

6 is a schematic diagram illustrating an example of a timing signal configuration output from the controller 140. According to FIG. 6, the timing signal may be implemented as two pulse signals. That is, the first pulse signal may indicate a processing period of the main video signal and the second pulse signal may indicate a processing period of the sub video signal.

7 is a flowchart illustrating a noise removing method according to an embodiment of the present invention. According to FIG. 7, when the main video signal and the sub video signal are received (S710), the synthesized video signal is synthesized by synthesizing them (S720).

Next, the display position of the main image and the sub image is checked to generate a timing signal for displaying the main video signal processing section and the sub video signal processing section (S730).

Next, after detecting the amount of noise separately for each of the main video signal and the sub video signal according to the timing signal (S740), the amount of attenuation corresponding to the detected amount of noise is individually reduced for the main video signal and the sub video signal. The noise is attenuated (S750). Accordingly, different attenuation levels may be applied to each of the main video signal and the sub video signal, thereby effectively removing noise.

As described above, according to the present invention, the amount of noise is separately detected for the main video signal and the sub video signal, and then a noise attenuation operation is performed to a degree corresponding to the detected noise amount. Accordingly, noise can be effectively attenuated with respect to both the main video signal and the sub video signal, thereby improving image quality. In particular, by using the timing signal, noise can be attenuated with respect to both the main video signal and the sub video signal without additional hardware, thereby reducing the display device manufacturing cost, volume, and the like.

In addition, although the preferred embodiment of the present invention has been shown and described above, the present invention is not limited to the specific embodiments described above, but the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Of course, various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (10)

A first signal input unit for receiving a main video signal; A second signal input unit receiving a sub image signal; A signal processor for outputting a composite video signal obtained by synthesizing the main video signal and the sub video signal; A controller configured to output a timing signal for selectively processing the main video signal and the sub video signal; A noise detector configured to perform a noise detection operation on the composite video signal according to the timing signal to separately detect an amount of noise included in each of the main video signal and the sub video signal; And, A noise reduction operation is performed by applying a weight corresponding to the amount of noise individually detected for each signal from the noise detector to the composite video signal according to the timing signal, thereby performing the noise reduction operation on each of the main video signal and the sub video signal. And a noise attenuator for individually attenuating the noise. The method of claim 1, The control unit, A processing section for the main image signal and a processing section for the sub image signal are determined according to a main image position displayed by the main image signal and a sub image position displayed by the sub image signal. Device. The method of claim 2, The timing signal may include a first pulse signal indicating a processing period for the main image signal and a second pulse signal indicating a processing period for the sub image signal. The method of claim 3, The noise detector, The amount of noise detected from the composite video signal while the first pulse signal is applied from the controller is provided as the main noise amount to the noise reduction unit, and the composite video signal while the second pulse signal is applied from the controller. And providing the second noise amount detected from the noise attenuation portion as a sub noise amount. The method of claim 4, wherein The noise reduction unit, When the first pulse signal is applied from the controller, the noise of the composite video signal is attenuated to a degree corresponding to the amount of main noise. When the second pulse signal is applied from the controller, the attenuation degree to correspond to the amount of sub noise. And attenuating noise of the composite video signal. In the noise reduction method of the display device, (a) receiving a main video signal and a sub video signal; outputting a composite video signal obtained by combining the main video signal and the sub video signal; (c) generating a timing signal for selectively processing the main video signal and the sub video signal; performing a noise detection operation on the composite video signal according to the timing signal to separately detect an amount of noise included in each of the main video signal and the sub video signal; And, (e) applying a weight corresponding to the amount of noise detected separately for each signal to the composite video signal according to the timing signal, and then performing a noise reduction operation for each of the main video signal and the sub video signal. And attenuating the noise individually. The method of claim 6, Step (c) is, Determining a processing section for the main video signal and a processing section for the sub video signal according to a main image display position displayed by the main video signal and a sub image display position displayed by the sub video signal; Noise reduction method comprising the. The method of claim 7, wherein Step (c) is, And generating and outputting a timing signal including a first pulse signal indicating a processing section of the main video signal and a second pulse signal indicating a processing section of the sub video signal. The method of claim 8, In step (d), Outputting a noise amount detected from the composite video signal as a main noise amount while the first pulse signal is output; And, And outputting an amount of noise detected from the composite video signal as a sub-noise amount while the second pulse signal is output. The method of claim 9, In step (e), Attenuating the noise of the composite video signal to an attenuation degree corresponding to the main noise amount while the first pulse signal is output; And And attenuating the noise of the composite video signal to a degree of attenuation corresponding to the amount of sub-noise while the second pulse signal is output.

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