KR101666897B1 - Improving method for image display and image display device thereof - Google Patents

Abstract

The present invention relates to an image quality improving method and a video display apparatus therefor, and more particularly, to a video quality improvement method and a video display apparatus capable of improving a picture quality deterioration caused by a reception failure of a received signal.

Description

TECHNICAL FIELD [0001] The present invention relates to an image display method,

The present invention relates to an image quality improving method and a video display apparatus therefor, and more particularly, to a video quality improvement method and a video display apparatus capable of improving a picture quality deterioration caused by a reception failure of a received signal.

Broadcasters transmit content, such as video or audio data, produced through a terrestrial transmission medium such as terrestrial, cable or satellite broadcasting. The transmitted content is transmitted in the form of a radio frequency signal (RF signal), and the transmitted signal is received through an image display device of an individual user. Here, the video display device refers to a digital broadcast receiver such as a digital TV or a personal computer (PC).

A signal transmitted in the form of a high frequency signal or the like may not be received by the user's image display apparatus due to a problem of transmission. In addition, even if a signal is received, a signal having a small signal size or a damaged signal may be received so that the broadcasting company can not display an intended image.

1 is a view showing a general video display device.

The tuner 110 receives a signal transmitted from the outside.

The decoder 120 decodes a signal output from the tuner and outputs the decoded signal.

The display unit 130 displays an image screen according to a signal output from the decoder.

The tuner 110 receives a frequency signal that exists over a wide band. Specifically, the tuner 110 is a device that selects and receives only signals within a predetermined frequency bandwidth. A signal input to the tuner 110 must be received at a predetermined electric field strength or higher to display a correct image.

That is, when the size of the signal applied to the tuner 110 is too small or the received signal can not be inputted to the tuner 110 due to the change of the reception environment, the display unit 130 displays the intended image screen I can not do it.

In addition, an error may occur in the decoding of the received signal due to the noise applied in the decoding process of the decoder 130. [ Also in this case, the display unit 130 can not display the image screen intended by the broadcaster.

The reception error of the reception signal due to the change of the reception environment or the occurrence of the decoding error due to the noise input deteriorates the image quality of the image display device. In addition, since a broadcaster can not display an intended video image, a problem that broadcast reception is not performed smoothly occurs.

Therefore, it is necessary to solve the image quality degradation problem of the image display device due to the reception failure of the received signal.

The present invention relates to a picture quality improvement method and a picture display apparatus therefor, and more particularly, to a picture quality improvement method capable of improving a picture quality deterioration phenomenon caused by a reception failure of a received signal and a video display apparatus .

The present invention relates to an image quality improving method and a video display apparatus therefor, and more particularly, to a video quality improvement method capable of preventing screen breakage or screen breakage of a displayed video screen and a video display device .

According to another aspect of the present invention, there is provided a picture quality improvement method including: storing first frame data in which a received signal received in a previous cycle is decoded; Storing second frame data obtained by decoding the received signal in a predetermined period following the previous period; Determining whether an error has occurred in the received signal; Generating a motion vector between the first frame data and the second frame data if the error occurs; And generating third frame data to be displayed in a subsequent period subsequent to the predetermined period based on the motion vector.

In addition, the step of storing the first frame data may include generating a first group of pictures including the first frame data.

The step of storing the second frame data may include generating a second group of pictures including the second frame data.

In addition, the predetermined period is a current display operation period, the previous period is a display operation period immediately before the current display operation period, and the subsequent period is a display operation period immediately after the current display operation period.

The step of determining whether an error has occurred in the received signal may include determining whether a value of a carrier-to-noise ratio of the received signal received in the subsequent period is less than or equal to a predetermined threshold value, It may be determined that an error has occurred in the received signal if it is determined that the error is less than or less than the threshold value.

The step of generating a motion vector between the first frame data and the second frame data may further comprise the step of comparing intra-coded frame data of the first pixel group with intra-coded frame data of the second pixel group corresponding thereto, A motion vector can be generated.

The generating of the motion vector between the first frame data and the second frame data may further include comparing predictive encoded frame data of the first pixel group with predictive encoded frame data of the second pixel group corresponding thereto, A motion vector can be generated.

The generating of the motion vector between the first frame data and the second frame data may include comparing bidirectionally predictive encoded frame data of the first pixel group with bi-predictive encoded frame data of the second pixel group corresponding thereto Thereby generating the motion vector.

In addition, the image quality improvement method according to an embodiment of the present invention may further include displaying the third frame data generated in the subsequent period.

An image display apparatus according to an embodiment of the present invention includes a tuner for selectively receiving a reception signal having a predetermined frequency band; A decoder for decoding the received signal to generate frame data; A storage element for storing first frame data in which a received signal received in a previous period is decoded and second frame data in which a received signal in a predetermined period following the previous period is decoded; And a display unit for displaying the decoded received signal. The decoder may determine whether an error has occurred in the received signal, generate a motion vector between the first frame data and the second frame data if the error occurs, and determine, based on the motion vector, Lt; / RTI > frame data to be displayed at a later period.

The decoder may determine whether a value of a carrier-to-noise ratio of the received signal received in the subsequent period is less than or equal to a predetermined threshold value, and if it is determined that the value is less than or equal to the predetermined threshold value, It can be determined that an error has occurred in the received signal.

An image display apparatus according to an embodiment of the present invention includes a tuner for selectively receiving a reception signal having a predetermined frequency band; A decoder for decoding the received signal to generate frame data; A storage element for storing first frame data in which a received signal received in a previous period is decoded and second frame data in which a received signal in a predetermined period following the previous period is decoded; A controller for determining whether an error has occurred in the received signal and generating a motion vector between the first frame data and the second frame data if the error occurs; And a display unit for displaying the decoded received signal.

Then, the decoder generates third frame data to be displayed in a subsequent cycle subsequent to the predetermined cycle based on the motion vector.

Also, the controller may determine whether the value of the carrier-to-noise ratio of the received signal received in the following period is less than or equal to a certain threshold value, and if it is determined that the value is less than or equal to the predetermined threshold value, It can be determined that an error has occurred in the received signal.

The image quality improvement method and image display apparatus according to the present invention can predict and generate frame data to be displayed at a time point after a reception signal error occurs by using a motion vector when a reception signal error occurs due to a reception failure of a reception signal.

Accordingly, by displaying the frame data generated by using the motion vector at a point in time after the occurrence of the reception signal error, it is possible to improve the picture quality deterioration due to the screen breakage phenomenon or the screen break phenomenon that may occur at the time point after the reception signal error occurs .

1 is a view showing a general video display device.
FIG. 2 is a graph showing changes in field strength of a received signal according to operation periods in which a received signal is received and displayed.
3 is a view illustrating an image display apparatus according to an embodiment of the present invention.
4 is a flowchart illustrating an image quality improvement method according to an embodiment of the present invention.
5 is a diagram showing that a received signal is decoded and generated as frame data.

The objects, features and advantages of the present invention will be more readily understood by reference to the accompanying drawings and the following detailed description. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

2 is a graph showing changes in electric field intensity of a received signal according to an operation cycle in which a received signal is received and displayed.

Referring to FIG. 2, the x-axis represents time and the y-axis represents the electric field strength of a received signal received by the image display device. The time axis (x-axis) is indicated by the period T interval. Here, the period T represents a time interval required for the image display apparatus to display an image screen according to a group of pictures (GOP). A group of pictures (GOP) may consist of one frame data or a plurality of frame data.

That is, the image data corresponding to the image screen to be displayed at intervals of the period T is received, and the image screen displayed through the image display device changes at intervals of the period T. Or a picture group (GOP) of frame data corresponding to an image screen to be displayed at intervals of period T is changed.

If the period T is referred to as a current time period and the time period immediately preceding the period T is referred to as a previous time period T-1, the electric field intensity of the received signal is maintained at about a until the period T, The intensity of the electric field is reduced to have a value of approximately c. Further, the time periods subsequent to the period T are sequentially (T + 1), (T + 2), and (T + 3). Hereinafter, the periods T, (T-1), and (T + 1) are referred to as a predetermined period, a preceding period, and a subsequent period, respectively.

The causes of the decrease of the electric field strength of the received signal include a problem on the transmission line, an instantaneous lightning strike, an obstacle present on the transmission path due to the movement of the airplane, or a climate change.

Due to the above-described cause, the field strength of the received signal can be sharply reduced based on a certain point in time. Here, the predetermined point of time is an instantaneous occurrence of the lightning stroke, an obstacle occurrence point on the transmission path due to the movement of the airplane, and the like.

The electric field strength of the received signal must be maintained at a certain level or more in order to reproduce the image by receiving the received signal. If the electric field intensity of the received signal is reduced to a certain level or less, a screen image corresponding to the received signal may be broken or a screen may be interrupted. The image quality of the image screen may be deteriorated accordingly.

Hereinafter, an image quality improvement method and image display apparatus according to an embodiment of the present invention, which can improve a picture quality degradation due to a screen break phenomenon or a screen break phenomenon that may occur due to a decrease in electric field intensity of the received signal 3 to Fig. 5.

3 is a view illustrating an image display apparatus according to an embodiment of the present invention.

3, an image display apparatus according to an exemplary embodiment of the present invention includes a tuner 310, a demodulator 320, a demultiplexer 330, a decoder 340, a display 350, a controller 360 ), A storage element unit 370, and an antenna 380.

An antenna 380 receives a signal transmitted from a broadcasting station or satellite. A broadcast station or the like can transmit a high frequency signal (or a radio frequency signal), and accordingly, the antenna 380 receives a high frequency signal.

The tuner 310 selects and receives a reception signal having a predetermined frequency. Then, the reception signal is converted into an intermediate frequency signal (IF signal). That is, the tuner 310 tunes a received signal (RF signal) transmitted to a predetermined broadcast channel that the image display device wants to view or hear.

The demodulator 320 receives the intermediate frequency signal output from the tuner 310, demodulates the intermediate frequency signal, and outputs the demodulated intermediate frequency signal. That is, the demodulation unit 320 restores the received signal to the original video signal, which is a signal before being transmitted by the broadcasting station or satellite.

The demultiplexer 330 demultiplexes the audio data and the video data from the demodulated broadcast signal.

The demultiplexing of the audio data and the video data can be controlled by the control unit 360. The demultiplexed audio data and video data are transmitted to the decoder 340.

The decoder 340 decodes the received signal to generate frame data. Specifically, the decoder 340 generates the first frame data by decoding the received signal in the previous period T-1, generates the second frame data by decoding the received signal in the current period T do. Then, the first and second frame data are stored in the storage element unit 370.

The decoder 340 may decode a received signal to generate a picture group (GOP) including a plurality of the frame data at predetermined intervals (T intervals). That is, the first frame data is one frame data included in the picture group (first picture group) generated by decoding the reception signal received in the previous period T-1, the second frame data is the current frame T, Is one frame data included in the picture group (second picture group) generated by decoding the received signal.

Then, the decoder 340 determines whether an error has occurred in the received signal. If it is determined that an error has occurred, a motion vector between the first frame data and the second frame data is generated. Subsequently, the generated third motion vector is used to generate third frame data to be displayed in a subsequent period (T + 1) immediately following the current period (T). Here, the control unit 360 may determine whether an error has occurred in the received signal.

The operation of the decoder 340 will be described in detail with reference to FIG. 4 and FIG.

The display unit 350 may internally include a display panel (not shown). The display unit 350 displays an image screen according to the frame data transmitted from the decoder 340 through the display panel.

The control unit 360 controls the overall function of the video display device and controls the decoded audio data and the video data to be output from the display unit 350.

The storage element unit 370 stores data transmitted from the decoder 340 or the controller 360. In addition, the storage element unit 370 may perform a data storage operation in response to the control of the controller 360.

4 is a flowchart illustrating an image quality improvement method according to an embodiment of the present invention.

Referring to FIG. 4, an image quality improvement method according to an exemplary embodiment of the present invention stores frame data of a previous period (operation 410). (For example, (T-1)) of a predetermined period (for example, T), which is a period of receiving the current reception signal. The frame data of the previous period T-1 is frame data obtained by decoding the received signal transmitted in the previous period T-1, hereinafter referred to as 'first frame data'.

With respect to the operation of step 410, generating the first frame data by decoding the received signal received in the previous period T-1 may be performed in the decoder 340. [ The first frame data may be stored in the storage element unit 370.

In step 420, frame data obtained by decoding the received signal in a predetermined period T following the previous period T-1 is stored. Herein, the predetermined period (T) refers to a period immediately after the previous period of step 410. Hereinafter, frame data at a predetermined period T will be referred to as 'second frame data'.

With respect to the operation of step 420, generating the second frame data by decoding the received signal in the predetermined period T may be performed by the decoder 340. [ The second frame data may be stored in the storage element unit 370.

The first and second frame data in steps 410 and 420 will be described in detail with reference to FIG.

5 is a diagram showing that a received signal is decoded and generated as frame data.

Referring to FIG. 5, a group of pictures (GOP) including a plurality of frame data is generated during each period (T-1, T, and T + 1), as described above.

Specifically, during a period (T-1), a picture group (GOP) composed of a plurality of frame data 501, 502, 503, and 504 corresponding to the received signal in the period T-1 is generated. That is, a first picture group including a plurality of frame data 501, 502, 503, and 504 is generated by decoding a received signal received in the (T-1) period. Here, the frame data generated during one period (for example, (T-1)) forms one picture group (GOP).

During the current period T period, a second picture group including a plurality of frame data 511, 512, 513, and 514 corresponding to the received signal in the T period is generated.

Subsequently, during the (T + 1) period, a plurality of frame data 521, 522, 523 and 524 corresponding to the received signal in the period T + 1 are generated.

In one picture group (GOP), an intra-coded frame (I frame) data, a bidirectional-coded frame (B frame) data, and a predictive- coded frame - 'P frame') data. In FIG. 5, intra-coded frame data is denoted by 'I', bidirectional predictive coded frame data is denoted by 'B', and predictive encoded frame data is denoted by 'P'.

One picture group (GOP) may include a plurality of frame data, and as shown, I, B, B, and P frame data may be sequentially arranged.

The number of frame data included in one picture group (GOP) varies, and the order in which the I, B, and P frame data are arrayed is also very diverse. It is apparent to those skilled in the art Therefore, the detailed description will be omitted.

It is determined whether an error has occurred in the received signal (operation 430).

In step 430, the occurrence of an error in the received signal indicates that a failure or an error has occurred in reception of the received signal at a subsequent period (for example, after T + 1 cycle) of a predetermined period (for example, T period) .

Whether or not an error has occurred in the received signal in step 430 can be determined by determining whether there is a possibility of a screen break or an image screen being cut off when an image decoded by the received signal is displayed.

When an error occurs in the received signal, the electric field strength of the received signal is weak, so that the user can not display the intended image screen. That is, when the reception signal is received by the tuner 310 and the image screen corresponding thereto is displayed in a state where the electric field strength of the reception signal is weak, the screen is broken or the image screen is cut off and the intended image screen can not be displayed . As described above, the cause of the decrease of the electric field strength of the received signal is a problem on the transmission line, an instantaneous lightning stroke, an obstacle present on the transmission path due to the movement of the airplane, or a climate change.

In step 430, whether or not an error has occurred in the received signal is determined by determining whether the Carrier to Noise (CN) value of the received signal received in the following period (T + 1) is below a certain threshold value , It can be determined that an error has occurred in the received signal if it is determined that the carrier-to-noise ratio value is less than or equal to a predetermined threshold value.

If the electric field intensity of the received signal is weak and the carrier-to-noise ratio (CN) value is less than a certain threshold value, the above-mentioned screen breakage or breakage of the image screen occurs. Accordingly, when the carrier-to-noise ratio (CN) value is less than or equal to the predetermined threshold value, it can be determined that the reception signal error in step 430 has occurred.

The value of the carrier-to-noise ratio is a recommendation in the Moving Picture Experts Group (MPEG) standard and is specified to be below a certain threshold value. In accordance with the MPEG standard, the value of the carrier-to-noise ratio (CN) must be more than a certain value or exceed a certain value in order to guarantee the image quality of the image screen to a certain level or more. Here, the limit value of the carrier-to-noise ratio (CN) for ensuring the image quality of the image screen to a certain level or more according to the MPEG standard becomes the above-mentioned 'constant threshold value'.

The operation of step 430 may be performed in the decoder 340. In addition, the operation of step 430 may be performed by the control unit 360.

If it is determined in step 430 that no error has occurred in the received signal, the receiver decodes the received signal in a subsequent period (for example, (T + 1) period) to display the generated image screen ). Here, the image screen is generated according to the frame data generated by decoding the received signal.

If it is determined in step 430 that an error has occurred in the received signal, a motion vector between the first frame data and the second frame data is generated (step 440).

Here, the first frame data can be read by using the stored frame data in step 410, and the second frame data can be read by using the stored frame data in step 420. [

The motion vector of step 440 may include intra-coded frame data among pixel groups of the previous period (for example, (T-1) period) and intra-coded frame data of a pixel group of a predetermined period Can be generated by comparing data. That is, a 501-frame data is used as the first frame data, and a 511-frame data is used as the second frame data to generate a motion vector between 501-frame data and 511-frame data.

In addition, the motion vector of step 440 may be predictively encoded among pixel groups of a predetermined period (for example, T period) corresponding to predictive encoded frame data of a pixel group of a previous period (for example, (T-1) period) And may be generated by comparing frame data.

That is, a motion vector between 502 or 503 frame data and 512 or 513 frame data is generated using 502 or 503 frame data as first frame data and 512 or 513 frame data as second frame data. Specifically, a motion vector may be generated by comparing 502 frame data and 512 frame data corresponding thereto, or a motion vector may be generated by comparing 503 frame data and 513 frame data corresponding thereto.

The motion vector of step 440 is generated by comparing bidirectional predictive coded frame data among pixel groups of a previous cycle (for example, (T-1) cycle) and bidirectionally predictive encoded frame data of a pixel group of a predetermined cycle corresponding thereto . That is, 504 frame data is used as the first frame data, and 514 frame data is used as the second frame data, thereby generating a motion vector between 504 frame data and 514 frame data.

Then, the third frame data to be displayed is generated in a subsequent period (for example, (T + 1) period) subsequent to the predetermined period (for example, T period) based on the motion vector generated in step 440 Step 450). Hereinafter, the call is a period immediately after a predetermined period.

Since the motion vector includes direction information of moving the image screen in a predetermined cycle, if a motion vector in a predetermined cycle is known, an image screen to be displayed in a subsequent cycle can be predicted and generated. Accordingly, in step 450, frame data corresponding to an image screen to be displayed in a subsequent period (for example, (T + 1) period) is generated using the motion vector generated in step 440. The frame data generation operation in step 450 may be performed in the decoder 340. [

Then, in step 460, an image screen according to the frame data generated in step 450 is displayed using the frame data generated in step 450. FIG. The display of the image screen in step 460 is performed by the display unit 350 under the control of the controller 360. [

The terminology used in the present invention is defined in consideration of the function of the present invention. It may vary depending on the intention or custom of the technician working in the field, .

The present invention is not limited to the above-described embodiments and various changes and modifications may be made by those skilled in the art, which is included in the spirit and scope of the present invention as defined in the appended claims.

310: Tuner
320: Demodulator
330: Demultiplexer
340: decoder
350:
360:
370:
380: Antenna
501, 511, 521: Intra-coded frame ('I frame') data
502, 503, 512, 513, 522, 523: Bidirectional-coded frame (B frame) data
504, 514 and 524: Predictive-coded frame (P frame) data

Claims (14)

Storing first frame data in which a received signal received in a previous period is decoded;
Storing second frame data obtained by decoding the received signal in a predetermined period following the previous period;
Determining whether an error has occurred in the received signal;
Generating a motion vector between the first frame data and the second frame data if the error occurs; And
And generating third frame data to be displayed in a subsequent period subsequent to the predetermined period based on the motion vector,
Wherein the step of determining whether an error has occurred in the received signal comprises:
And determining that an error has occurred when the magnitude of the field strength of the received signal decreases to a predetermined size or less. The method according to claim 1,
Wherein the step of storing the first frame data comprises:
And generating a first group of pictures including the first frame data,
Wherein the step of storing the second frame data comprises:
And generating a second group of pictures including the second frame data. 3. The method of claim 2,
The predetermined period is a current display operation period,
Wherein the previous period is a previous display operation period of the current display operation period,
Wherein the subsequent period is a display operation period immediately after the current display operation period. Claim 4 has been abandoned due to the setting registration fee. 3. The method of claim 2,
Wherein the step of determining whether an error has occurred in the received signal comprises:
Determining whether a value of a carrier-to-noise ratio of the received signal received in the subsequent period is less than or equal to a predetermined threshold value, and if it is determined that the value is less than or equal to the predetermined threshold value, . Claim 5 has been abandoned due to the setting registration fee. 3. The method of claim 2, wherein generating the motion vector between the first frame data and the second frame data comprises:
Wherein the motion vector is generated by comparing intra-coded frame data of the first picture group with intra-coded frame data of the second picture group corresponding thereto. Claim 6 has been abandoned due to the setting registration fee. 3. The method of claim 2, wherein generating the motion vector between the first frame data and the second frame data comprises:
Wherein the motion vector is generated by comparing predictive coded frame data of the first picture group and predictive coded frame data of the second picture group corresponding thereto. Claim 7 has been abandoned due to the setting registration fee. 3. The method of claim 2, wherein generating the motion vector between the first frame data and the second frame data comprises:
Wherein the motion vector is generated by comparing bidirectional predictive coded frame data of the first picture group with bidirectional predictive coded frame data of the second picture group corresponding thereto. The method according to claim 1,
And displaying the third frame data generated in the subsequent period. A tuner for selectively receiving a reception signal having a predetermined frequency band;
A decoder for decoding the received signal to generate frame data;
A storage element for storing first frame data in which a received signal received in a previous period is decoded and second frame data in which a received signal in a predetermined period following the previous period is decoded; And
And a display unit for displaying the decoded received signal,
The decoder
Wherein when the magnitude of the field strength of the received signal is reduced to a predetermined size or less, it is determined that an error has occurred in the received signal, a motion vector between the first frame data and the second frame data is generated, And generates third frame data to be displayed in a subsequent period subsequent to the predetermined period. 10. The apparatus of claim 9, wherein the decoder
Decoding a received signal received in the previous period to generate a first group of pictures including the first frame data,
And generates a second group of pictures including the second frame data by decoding the received signal in the predetermined period. 11. The apparatus of claim 10, wherein the decoder
And determining whether a value of a carrier-to-noise ratio of the received signal received in the subsequent period is less than or equal to a certain threshold value and determining that an error is less than or equal to the predetermined threshold value, And determines that the image is generated. 11. The apparatus of claim 10, wherein the decoder
Comparing the intra-coded frame data of the first picture group with the intra-coded frame data of the second picture group corresponding thereto,
Compares the predictive encoded frame data of the first picture group with the predictive encoded frame data of the second picture group corresponding to the predicted encoded frame data,
By comparing bidirectionally predictive encoded frame data of the first picture group and predictive encoded frame data of the second picture group corresponding thereto,
And generates the motion vector. A tuner for selectively receiving a reception signal having a predetermined frequency band;
A decoder for decoding the received signal to generate frame data;
First frame data in which a received signal received in a previous cycle is decoded,
A storage element for storing second frame data obtained by decoding the received signal in a predetermined period following the previous period;
A controller for determining that an error has occurred when the magnitude of the field strength of the received signal is reduced to a predetermined size or smaller and generating a motion vector between the first frame data and the second frame data; And
And a display unit for displaying the decoded received signal,
The decoder
And generates third frame data to be displayed at a subsequent period subsequent to the predetermined period based on the motion vector. 14. The apparatus of claim 13, wherein the control unit
And determining whether a value of a carrier-to-noise ratio of the received signal received in the subsequent period is less than or equal to a certain threshold value and determining that an error is less than or equal to the predetermined threshold value, And determines that the image is generated.

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