KR20050073326A - Apparatus and method to implement the background of osd using switching plane - Google Patents

Abstract

The present invention is to implement a structure that can select the background color of the OSD, to effectively implement a graphical user interface such as data broadcasting with a flexible OSD display, the feature of the switching device between OSD layers is a plurality of subtitle signals through the receiver Or / and an OSD layer for receiving a video signal and performing a scaler, a background part for setting a background of the displayed screen to a predetermined color, and an upper layer for each pixel to be displayed at the same time among signals input through the OSD part And a switching plane outputting a control signal SP1 for setting a lower layer, a control signal SP2 for setting an insertion position of the background, and a control signal SP1 output from the switching plane. Determine upper layer and lower layer by pixel of OSD1 and OSD2 And an alpha blending processor for performing alpha blending and inserting the background through a control signal SP2, and a display unit for displaying an image processed by the alpha blending processor.

Description

OSD background implementation apparatus and method using switching plane {apparatus and method to implement the background of OSD using switching plane}

The present invention relates to a display device, and more particularly, to an apparatus and method for implementing an OSD background using a switching plane.

Recently, TV-related technologies are rapidly developing quantitatively and qualitatively as the technology of devices such as digital television, digital camera, PDA, etc. is changed from analog method to digital method. In particular, the number of channels broadcast on TV will increase exponentially by digital method that can operate much more channels than analog in terms of quantity.

Therefore, the user may not only utilize various channels by simply recognizing the names of some channels or broadcasting stations, but also may be difficult to watch the broadcasting programs he / she wants. Therefore, the recent digital broadcasting technology has a broadcasting information guide function for displaying the broadcasting program information of each channel provided from the broadcasting station on the screen so that the viewer can easily identify and select each broadcasting program. In order to cope with the development, the technical development of the broadcasting information guidance function is urgently required.

One of the methods currently used to solve such a demand is to separate additional information (subtitle signal and another video signal) such as EPG (Electronic Program Guide) transmitted along with the video signal from the receiver and then to one video signal. I am using On Screen Display (OSD), which is a superimposed display method.

The OSD (On Screen Display) is commonly used as a screen for adjusting a menu by placing a graphic layer on top of a video image. It also indicates transparency in the OSD layer. By setting a value and adjusting the transparency of a plurality of overlapping images, a plurality of images can be simultaneously displayed on one screen. This method is called alpha blending.

1 and 2 are hardware diagrams illustrating a method of implementing alpha blending according to the prior art. Assuming that an upper OSD layer is OSD1 and a lower OSD layer is OSD2, FIG. 1 is an upper layer. Is a diagram illustrating alpha blending, and FIG. 2 is a diagram illustrating alpha blending when OSD2 is a higher layer.

First, referring to FIG. 1, when the display unit 60 displays a portion where the OSD1 input to the first OSD unit 10 and the OSD2 input to the second OSD unit 20 overlap, the upper layer is displayed. Value of OSD1 Is processed using.

At this time, the Has a value between 0 and 1 when the intensity of the color to be displayed is 1. In other words, the alpha value of the OSD layer is between the minimum and maximum values that a color can have.

Therefore, for alpha blending, the color value of the upper layer OSD1 ( ) Is the alpha value of OSD1 ( Multiply by (30). Subsequently, the color value of the lower layer OSD2 is subtracted from the alpha value of 1 ( Multiply by 40.

The multiplied two result values are added to output the color value to be finally displayed on the display unit 60.

The alpha blending method between the two layers is expressed by the following equation.

At this time, : Color value of OSD1, : Alpha value of OSD1

: Color value of OSD2, : Color value to be displayed.

Next, referring to FIG. 2, when the OSD 1 input to the first OSD unit 10 and the OSD 2 input to the second OSD unit 20 overlap each other, the upper portion of the display unit 60 displays an upper portion. Alpha value of the OSD2 layer Is processed using.

At this time, the Has a value between 0 and 1 when the intensity of the color to be displayed is 1. In other words, the alpha value of the OSD layer is between the minimum and maximum values that a color can have.

For alpha blending, we first set the color value of the upper layer OSD2 ( ) Is the alpha value of OSD2 ( Multiply by 42. Subsequently, the color value of the lower layer OSD1 is subtracted from the alpha value of 1 ( Multiply by (32).

The multiplied two result values are added to output the color value to be finally displayed on the display unit 60.

The alpha blending method between the two layers is expressed by the following equation.

However, such alpha blending is difficult to move up and down smoothly between the upper layer and the lower layer during the alpha blending process.

That is, the alpha blending is calculated by setting the same alpha value in image units at the front of the alpha blending processor when multiplying the alpha value in each layer, so that pixels according to one image cannot be alpha blended through other alpha values. Will be lost. Therefore, partial vertical movement between the upper layer OSD1 and the lower layer OSD2 becomes impossible.

For example, assuming that OSD1 is the upper layer and OSD2 is the lower layer, as shown in FIG. 3, an area (a) in which OSD1 as an upper layer is displayed and an area (b) in which OSD2 as a lower layer are displayed are displayed on the display. At this time, in the case where the lower layer OSD2 is selectively viewed only in a predetermined area c including the upper layer OSD1, the alpha value of the OSD1 ( If 1) becomes '1' and has 100% opacity, the upper and lower layers may be displayed in reverse order, but OSD2, which is a lower layer, may not be selectively displayed only in the overlapping predetermined region c.

Accordingly, the present invention has been made to solve the above problems, the device having a layer (switching plane) to determine the top and bottom between the two layers to selectively determine the layer to be placed on the pixel by pixel And to provide a method.

Another object of the present invention is to provide various display effects by allowing the upper and lower layers to be freely adjusted.

Still another object of the present invention is to implement a structure capable of selecting a background color of the OSD, thereby effectively implementing a graphical user interface such as data broadcasting with a flexible OSD display.

Features of the OSD background implementation apparatus using a switching plane according to the present invention for achieving the above object is a feature of the switching device between the OSD layer is to perform a scaler by receiving a plurality of subtitle signals or / and video signals through the receiver An OSD unit, a background unit for setting a background of the displayed screen to a predetermined color, a control signal SP1 for setting an upper layer and a lower layer for each pixel to be displayed at the same time among signals input through the OSD unit; An upper layer and a lower layer for each pixel of the OSD1 and OSD2 are switched through a switching plane for outputting a control signal SP2 for setting the insertion position of the background and a control signal SP1 output from the switching plane. Determine and perform alpha blending, and perform background insertion through control signal SP2. Performing it consists of including alpha blending processing unit and a display unit for displaying the image processed by the alpha blending processing.

Another aspect of the OSD background realization apparatus using a switching plane according to the present invention for achieving the above object is a first OSD unit for performing a scaler by receiving a subtitle signal and / or video signal OSD1 from the outside through a receiver; And a second OSD unit which performs a scaler by receiving OSD2, which is a caption signal and / or an image signal simultaneously displayed on the same screen as the OSD1, and a background of the screen on which the OSD1 and OSD2 are displayed in a predetermined color. Outputs a background signal to be set, a control signal SP1 for setting an upper layer and a lower layer for each pixel among signals input through the first and second OSD units, and a control signal SP2 for inserting the background. Pickings of the OSD1 and OSD2 through a switching plane and a control signal SP1 output from the switching plane It is configured to include an alpha blending processing unit for performing alpha blending by determining the upper layer and the lower layer for each, and the background insertion through a control signal (SP2), and a display unit for displaying an image processed by the alpha blending processing unit. have.

In this case, the alpha blending processor determines an upper layer and a lower layer for each pixel of the OSD1 and OSD2 through a control signal output from the switching plane, and uses an alpha value of the upper layer to calculate transparency between lower layers. And a BG selector for selectively outputting one of the pixel color values of the background and the lower layer according to an input signal indicating whether the OSD is used in the background externally, and whether or not the corresponding pixel is in the OSD area from the outside. An OSD-BG selector for selectively outputting one of an output value C _(A) of the OSD alpha blending _unit and an output value C _(B) of the BG selector according to an input signal, and a control signal of the switching plane OSD / BG-Video to selectively output any one of the output value (C _(C) ) and the lower layer (C _V ) of the OSD-BG selector through It is preferable to include the o selection part.

The control signal output from the switching plane has a value of '0' or '1' having a size of 1 bit and has the same value to control the OSD alpha blending unit and the OSD / BG-video selection unit. desirable.

A feature of the OSD background implementation method using a switching plane according to the present invention for achieving the above object is that when a plurality of caption signals and / or video signals are received from the outside, a plurality of simultaneous input to a screen Outputting the subtitle signal and / or the video signal for each pixel by using a plurality of OSD units, and outputting characteristic information of the signal input together with the plurality of subtitle signals and / or video signals received through the receiver; Setting a top and bottom order of the layer for each pixel according to each subtitle signal and / or an image signal, and generating a control signal for determining an area of a background, and through the plurality of OSD units through the generated control signal. Set the color value of each pixel of input multiple subtitle signal and / or video signal or each pixel of background signal Is makin comprises the steps of displaying the final color value of the alpha blending process on the display unit to perform alpha blending.

In this case, the alpha blending process may determine the upper and lower layers for each pixel of the plurality of signals input through the plurality of OSD units through the generated control signal, and process alpha blending to process the final color value (C _{( A) A} first output step of outputting a ₎ ) and selectively outputs any one of the color value of the background pixel and the pixel color value of the lower layer input through the input signal indicating whether the OSD is used in the background from the outside Outputting the final color value C _(A ) and the second outputting step of the corresponding pixel outputted through the first outputting step through an input signal indicating whether or not the corresponding pixel belongs to the OSD region from the outside. A third output for receiving a color value of the background pixel or a pixel color value of the lower layer OSD2 outputted through A display unit which receives a color value of a pixel output in the third output step and a pixel color value of a lower layer through a control signal for determining a region of the background and selectively outputs any one of the final color values It is preferable to include a fourth output step for outputting to.

The characteristic information of the signal is preferably at least one of transparency, color value, height, and size of each pixel.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of embodiments with reference to the accompanying drawings.

A preferred embodiment of the switching method between OSD layers according to the present invention will be described with reference to the accompanying drawings.

4 is a diagram illustrating a structure of implementing alpha blending using a switching plane according to the present invention.

Referring to FIG. 4, first, the first OSD unit 100, which performs a scaler by receiving OSD1, which is a caption signal and / or an image signal, from the outside, is performed on the same screen as the OSD1 through the receiving unit. The second OSD unit 200 receives a subtitle signal and / or an image signal OSD2 displayed at the same time and performs a scaler. A switching plane 400 for outputting a control signal for setting an upper layer and a lower layer for each pixel among the signals input through the first and second OSD units 100 and 200, and the switching. OSD alpha blending unit 300 for performing alpha blending by determining the upper layer and the lower layer for each pixel of the OSD1 and OSD2 through the control signal SP output from the plane 400, and the OSD alpha blending unit 300 The display unit 500 for displaying the image processed in step (b).

At this time, the OSD alpha blending unit 300 is the alpha value of the OSD1 to each pixel of the OSD1 signal output from the first OSD unit 100 Multiply by The alpha value of OSD2 in each pixel of the multiplier 310 and the OSD2 signal output from the second OSD unit 200. Multiply by The alpha value of OSD1 in each pixel of the multiplier 320 and the OSD1 signal output from the first OSD unit 100. Multiply by The alpha value of OSD2 in each pixel of the multiplier 330 and the OSD2 signal output from the second OSD unit 200. Multiply by The multiplication unit 340 is configured. And said Multiplication unit 310 and A first mux 350 selectively outputting one of color values of pixels output from the multiplier 320 according to a control signal output from the switching plane 400, and Multiplication unit 330 and The second mux 360 selectively outputs one of the color values of the pixels output from the multiplier 340 according to the control signal output from the switching plane 400, and the first mux 350. And an adder 370 that calculates a final color value to be displayed by adding the color value of the pixel and the color value of the pixel output from the second mux 360 and outputs the color value to be displayed on the display unit 500.

When the alpha blending processed by the alpha blending processing unit 300 is expressed by an equation, Equation 3 is obtained.

At this time, : Color value of OSD1, : Color value of OSD2,

: Color value to be displayed.

And said And Is an alpha value selected from the first and second muxes 350 and 360, respectively, and is defined as shown in Table 1 below by the control signal SP output from the switching plane 400. In this case, Table 1 may be changed by the user's setting.

SP description 0 If OSD1 is higher One OSD2 is higher

The switching method between the OSD layers according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

5 is a flowchart illustrating a method of switching between OSD layers using a switching plane according to the present invention.

First, as shown in FIG. 5, when a plurality of caption signals and / or video signals are received from the outside (S10), a plurality of caption signals or / and video signals simultaneously input to one screen (2 for simplicity of explanation). OSD1 and OSD2 are input to the first OSD unit 100 and the second OSD unit 200, respectively (S20).

In this case, the caption signal and / or the video signal received through the receiver includes characteristic information of each signal. The characteristic information includes pixel transparency, color, height, and size information.

Accordingly, the switching plane 400 determines the top and bottom order for each pixel of the layer according to each video signal by inputting the characteristic information input together with the caption signal and / or the video signal, and generates a control signal accordingly (S30). ).

Subsequently, the first OSD unit 100 and the second OSD unit 200 perform scalers on the input OSD1 and OSD2 to output the alpha blending processing unit 300 for each pixel, and the switching plane 400 performs the scaler. The control signal corresponding to each pixel output to the alpha blending processing unit 300 is output through S40.

Then, the alpha blending processing unit 300 each pixel of the plurality of image signals OSD1 and OSD2 inputted through the first and second OSD units 100 and 200 through the control signal output from the switching plane 400. The alpha blending process is performed by determining the upper and lower layers of the star (S50).

That is, when the control signal SP output from the switching plane 400 is 0, the alpha blending processor 300 determines the pixel input from OSD1 as the upper layer and the pixel input from OSD2 as the lower layer. . In addition, when the control signal SP output from the switching plane 400 is 1, the alpha blending processor 300 determines a pixel input from OSD1 as a lower layer and a pixel input from OSD2 as an upper layer.

As such, when it is determined that the pixel input from the OSD1 is the upper layer and the pixel input from the OSD2 is the lower layer according to the control signal output from the switching plane 400, when displaying a portion where the two pixels overlap. The upper layer OSD1 is the alpha value And the lower layer OSD2 is alpha value. Alpha blended using.

In addition, if it is determined that the pixel input from the OSD2 is an upper layer and the pixel input from the OSD1 is a lower layer, when displaying a portion where two pixels overlap each other, the upper layer OSD2 is an alpha value. And the lower layer OSD1 is alpha value. Alpha blended using.

At this time, the And Has a value between 0 and 1 when the intensity of the color to be displayed is 1. In other words, the alpha value of the OSD layer is between the minimum and maximum values that a color can have.

Therefore, for alpha blending, the first layer is the color value ( ) Is multiplied by the alpha value. Subsequently, the lower layer color value is multiplied by 1 minus the alpha value. Then the sum of the two pixels adds up to 1, resulting in 100% opacity.

Therefore, the resultant color value to be displayed is added by adding the two result values multiplied by the multiplication result and displayed on the display unit 500 (S60).

Therefore, even when the opacity of the OSD1 and OSD2 is 100% and the alpha value is '1', the upper layer to be displayed can be determined for each pixel according to the control signal SP output from the switching plane as shown in Equation 4.

If SP = 1:

Here, when no signal is simultaneously input to one screen among a plurality of signals input to the first OSD unit 100 and the second OSD unit 200, the alpha blending processing unit 300 is bypassed and immediately OSD 1 or OSD 2 is displayed on the display unit 500. This is a general case and a detailed description thereof will be omitted.

In this way, the image displayed on the display unit 500 has the alpha value of the OSD1 when the OSD1 is the upper layer and the OSD2 is the lower layer as shown in FIG. 6. ) Becomes '1' to have 100% opacity, so that the OSD2 can be selectively viewed in a predetermined area (c) including the upper layer OSD1.

Table 2 is a graph showing the state of the control signal SP1 and the OSD of the switching plane for each region displayed on the display unit illustrated in FIG. 6.

domain - OSD SP Print (a) - on One OSD1 + OSD2 (b) - off - OSD2 (c) - x 0 OSD2 (d) - off One OSD2

In this case, OSD2 is displayed as it is in other areas (b) and (d) of the display unit 500.

As such, the display unit 500 may display a caption signal and / or a video signal located at a lower portion in the region (c), which is a predetermined region of the caption signal and / or a video signal located at an upper portion thereof. It is difficult to display the caption signal and / or the video signal only in a predetermined area (c), and to prevent the OSD2 signal from being displayed in the areas (b) and (d).

7 is a diagram illustrating a structure of implementing alpha blending according to the present invention for solving this problem.

Referring to FIG. 7, first, the first OSD unit 100 which receives the subtitle signal and / or the video signal OSD1 from the outside and performs a scaler, and the same screen as the OSD1 through the receiving unit from the outside A second OSD unit 200 which receives a caption signal and / or an image signal OSD2 simultaneously displayed on the screen and performs a scaler, and a background unit 600 which sets a background of a screen on which the OSD1 and OSD2 are displayed to a predetermined color. ), A control signal SP1 for setting an upper layer and a lower layer for each pixel among the signals input through the first and second OSD units 100 and 200, and a control signal SP2 for setting the insertion of the background. Determine an upper layer and a lower layer for each pixel of the OSD1 and OSD2 by using a switching plane 400 for outputting a) and a control signal SP1 output from the switching plane 400. Performing a wave blending, and is composed of alpha blending processing unit 300, a display 500 for displaying the image processed by the alpha blending processing unit 300 performs the background inserted through the control signal (SP2).

In this case, the alpha blending processor 300 determines the upper layer and the lower layer for each pixel of the OSD1 and the OSD2 through the control signal SP1 output from the switching plane 400, and determines the alpha value of the upper layer OSD1. OSD alpha blending unit 312 for calculating the transparency between the lower layers (OSD2) using the () and the pixel color values of the background and lower layers (OSD2) according to the value of the input signal BGColor_is_on indicating whether the OSD is used in the background from the outside. of any one of selective BG selecting section 314 for outputting the output value of the corresponding pixel from the outside of the OSD alpha blending unit 312 in accordance with the value of the input signal OSD_is_on indicating whether the part of the OSD area (C _{(a )} ) And the OSD-BG selector 316 for selectively outputting any one of the output value C _(B ) of the BG selector 314 and the control signal SP2 of the switching plane 400. The OSD / BG-video selection unit 318 selectively outputs any one of the output value C _(C) and the lower layer C _V of the OSD-BG selection unit 316.

In addition, the control signals SP1 and SP2 output from the switching plane 400 have a value of '0' or '1' having a size of 1 bit, have the same value, and the OSD alpha blending unit. It is desirable to control 312 and the OSD / BG-video selector 318.

The OSD background implementation method using the switching plane according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

8 is a flowchart illustrating a method for implementing an OSD background using a switching plane according to the present invention.

First, as shown in FIG. 8, when a plurality of caption signals and / or video signals are received through the receiver from the outside (S100), a plurality of caption signals or / and video signals simultaneously input to one screen (2 for simplicity of explanation). OSD1 and OSD2 are input to the first OSD unit 100 and the second OSD unit 200, respectively (S110).

In this case, the caption signal and / or video signal received through the receiver includes characteristic information of each signal, and the characteristic information includes pixel transparency, color, height, and size information.

Therefore, the switching plane 400 determines the top and bottom order and the region of the background of each pixel according to each video signal by inputting the characteristic information input together with the caption signal and / or the video signal, and determines the control signal accordingly. It generates (S120).

Subsequently, the first OSD unit 100 and the second OSD unit 200 scale the input OSD1 and OSD2 to output the OSD alpha blending unit 300 for each pixel, and the switching plane 400 The control signal SP1 for determining the order of the pixels for each pixel corresponding to each pixel output to the OSD alpha blending unit 312 through the scaler is output (S130).

Then, the OSD alpha blending unit 312 may include a plurality of image signals OSD1 input through the first and second OSD units 100 and 200 through the control signal SP1 output from the switching plane 400. The upper and lower layers for each pixel of OSD2 are determined to process alpha blending, and the color value C _(A) of the corresponding pixel is output (S140).

That is, when the control signal SP1 output from the switching plane 400 is '0', the OSD alpha blending unit 312 uses the pixel input from the OSD1 as the upper layer and the pixel input from the OSD2 as the lower layer. Judging by. In addition, when the control signal SP1 output from the switching plane 400 is '1', the OSD alpha blending unit 312 may convert a pixel input from OSD1 into a lower layer and a pixel input from OSD2 into an upper layer. To judge.

As such, when it is determined that the pixel input from the OSD1 is the upper layer and the pixel input from the OSD2 is the lower layer according to the control signal SP1 output from the switching plane 400, the overlapping portion of the two pixels is determined. When displaying, the upper layer OSD1 is the alpha value. And the lower layer OSD2 is alpha value. Alpha blended using.

In addition, if it is determined that the pixel input from the OSD2 is an upper layer and the pixel input from the OSD1 is a lower layer, when displaying a portion where two pixels overlap each other, the upper layer OSD2 is an alpha value. And the lower layer OSD1 is alpha value. Alpha blended using.

At this time, the And Has a value between 0 and 1 when the intensity of the color to be displayed is 1. In other words, the alpha value of the OSD layer is between the minimum and maximum values that a color can have.

Therefore, for alpha blending, the first layer is the color value ( ) Is multiplied by the alpha value. Subsequently, the lower layer color value is multiplied by 1 minus the alpha value. Then the sum of the two pixels adds up to 1, resulting in 100% opacity.

For example, even when the opacity of the OSD1 and OSD2 is 100% and the alpha value is '1', the upper layer to be displayed can be determined for each pixel according to the control signal SP output from the switching plane as shown in Equation 4. do.

If SP = 1:

In this way, the image displayed on the display unit 500 has the alpha value of the OSD1 when the OSD1 is the upper layer and the OSD2 is the lower layer as shown in FIG. 6. ) Becomes '1' so that the OSD2 can be additionally viewed in a predetermined area (c) including the upper layer OSD1.

Subsequently, the BG selector 314 receives a value of the input signal BGColor_is_on indicating whether the OSD is used in the background (S150), and through this, the color value of the background pixel inputted from the background unit 600 and the lower layer ( One of the values C _(B ) of the pixel color values of the OSD2 is selectively output (S160) (S170).

That is, when the input signal BGColor is on, the color value of the background pixel is output (S170). If the input signal BGColor is off, the color value of the lower layer pixel is output (S160).

In this way, the color value of the background pixel output from the BG selector 314 or the pixel color value of the lower layer OSD2 is different from the final color value C _{(A) to} be output from the OSD alpha blending unit 312. Together with the OSD-BG selection unit 316 is received.

The OSD-BG selector 316 receives an input value of the input signal OSD_is_on indicating whether the corresponding pixel belongs to an upper layer (OSD1) region from the outside (S180), and accordingly, output value C of the OSD alpha blending unit. _{One of (A)} ) and the output value C _(B ) of the BG selector are selectively output (S190) (S200).

That is, if the input signal OSD is on, the output value C _(A) of the OSD alpha blending unit 312 is output (S200). If the input signal OSD is off, the BG selection unit 314 is output. The output value C _(B ) is output (S190).

Subsequently, the OSD / BG-video selector 318 receives the output value of the OSD-BG selector 316 and the lower layer OSD2, and the OSD-BG selector according to the control signal SP2 of the switching plane. One of the output value C _(C ) of 316 and the pixel color value C _V of the lower layer OSD 2 is selectively output (S210).

That is, when the control signal SP2 input from the switching plane is '0', the output value C _(C) of the OSD-BG selector is output, and the control signal SP2 input from the switching plane is '1'. In this case, the pixel color value C _V of the lower layer is output.

The final pixel color value C _(D) output from the OSD / BG-video selection unit 318 is displayed on the display unit 500 (S220).

In this manner, when the image displayed on the display unit 500 assumes that OSD1 is the upper layer and OSD2 is the lower layer as shown in FIG. 9, the alpha value of the OSD1 ( ) Becomes '1' so that the OSD2 can be additionally viewed in a predetermined area (c) including the upper layer OSD1. In addition, the display unit 500 displays the caption signal and / or the video signal located at the lower part of the predetermined area (c) of the caption signal and / or the video signal located on the upper part, and the other areas (b) and ( The background color is displayed in the area d).

Table 3 is a graph showing the setting of the background, the control signal SP1 of the switching plane, and the state of the OSD for each region of the display unit 500 illustrated in FIG. 9.

domain background OSD SP Print (a) x on One OSD1 + OSD2 (b) off off One OSD2 (c) x x 0 OSD2 (d) on off One B

In this case, the setting of the background may use a video image having another OSD or apply a fixed color. However, in this case, the memory bandwidth and hardware cost used to read an image from the memory may be changed. If you apply a fixed color through the will increase significantly.

For example, in the case of DTV, the pixel according to one frame is 1280x720, so when using a video image with OSD, the memory bandwidth needs to be (1280x720) x data value (16 bits, 32 bits). Done.

In contrast, when a fixed color through the switching plane 400 is applied as in the present invention, the bandwidth of the memory is (1280x720) x the size of the control signal of the switching plane (1 bit). You can save size and bandwidth.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the embodiments, but should be defined by the claims.

As described above, the method for switching between OSD layers according to the present invention has the following effects.

First, it is possible to expect various display effects that could not be used in the conventional method by freely adjusting the upper and lower pixels for each layer between layers.

Second, by using the switching plane for setting the background, memory bandwidth and hardware cost can be reduced by at least 16 times.

Third, it can be utilized in all display devices using the OSD.

1 and 2 are hardware diagrams illustrating a method of implementing alpha blending according to the prior art.

3 illustrates an image displayed on a display unit according to the related art.

4 is a first embodiment showing a structure in which alpha blending is implemented using a switching plane according to the present invention.

5 is a flowchart illustrating a method of implementing alpha blending using the switching plane according to FIG. 4.

6 illustrates an image displayed on a display unit according to the first embodiment;

7 is a second embodiment showing a structure implementing alpha blending according to the present invention;

8 is a flowchart illustrating a method for implementing an OSD background using a switching plane according to FIG. 7.

9 illustrates an image displayed on a display unit according to a second embodiment;

* Explanation of symbols for main parts of the drawings

100: first OSD unit 200: second OSD unit

300: alpha blending processing unit 310: Multiplication

312: OSD alpha blending unit 314: BG selection unit

316: OSD-BG selector 318: OSD / BG-video selector

320: Multiplication Unit 330: Multiplication

340: Multiplication unit 350: the first mux

360: second mux 370: adder

400: switching plane 500: display unit

600: background part

Claims (7)

An OSD unit configured to receive a plurality of caption signals and / or video signals through a receiver to perform a scaler; A background unit for setting a background of the displayed screen to a predetermined color; Switching plane for outputting a control signal SP1 for setting an upper layer and a lower layer for each pixel to be displayed in the same area among the signals input through the OSD unit and a control signal SP2 for setting an insertion position of the background. plane), An alpha blending processor that performs alpha blending by determining an upper layer and a lower layer for each pixel of the OSD1 and OSD2 through a control signal SP1 output from the switching plane, and performs background insertion through a control signal SP2. Wow, And a display unit for displaying an image processed by the alpha blending processor. A first OSD unit configured to externally receive the subtitle signal and / or the video signal OSD1 through a receiver to perform a scaler; A second OSD unit configured to receive a scaler by receiving a subtitle signal and / or an image signal OSD2 simultaneously displayed on the same screen as the OSD1 through a receiver; A background unit for setting a background of a screen on which the OSD1 and OSD2 are displayed to a predetermined color; A switching plane outputs a control signal SP1 for setting an upper layer and a lower layer for each pixel among the signals input through the first and second OSD units, and a control signal SP2 for setting the insertion of the background. and, An alpha blending processor that performs alpha blending by determining an upper layer and a lower layer for each pixel of the OSD1 and OSD2 through a control signal SP1 output from the switching plane, and performs background insertion through a control signal SP2. Wow, And a display unit for displaying an image processed by the alpha blending processor. The method of claim 2, wherein the alpha blending processing unit An OSD alpha blending unit configured to determine an upper layer and a lower layer for each pixel of the OSD1 and OSD2 based on a control signal output from the switching plane, and calculate transparency between lower layers by using an alpha value of an upper layer; A BG selection unit for selectively outputting any one of a background color and a pixel color value of a lower layer according to an input signal indicating whether the OSD is used in the background; OSD selectively outputs one of the output value (C _(A) ) of the OSD alpha blending _unit and the output value (C _(B) ) of the BG selector according to an input signal indicating whether or not the corresponding pixel belongs to the OSD region from the outside With the BG selector, And an OSD / BG-video selection unit for selectively outputting any one of an output value C _(C) and a lower layer C _{V of} the OSD-BG selection unit through a control signal of the switching plane. OSD background implementation device. The method of claim 3, wherein The control signal output from the switching plane has a value of '0' or '1' having a size of 1 bit, has the same value, and controls the OSD alpha blending unit and the OSD / BG-video selection unit. OSD background implementation device. When a plurality of caption signals and / or video signals are received from the outside through a receiver, a plurality of caption signals and / or video signals simultaneously inputted on one screen may be scaled using a plurality of OSD units to output for each pixel. Steps, By using the characteristic information of a signal input together with a plurality of caption signals and / or video signals received through the receiving unit, a top and bottom order of layers for each pixel according to each caption signal and / or video signal are set, and a background region is set. Generating a control signal for determining; Performing alpha blending for setting a color value of each pixel of a plurality of subtitle signals and / or a video signal or a background signal inputted through the plurality of OSD units through the generated control signal; And displaying the alpha blended final color value on a display unit. The method of claim 5, wherein the alpha blending step First to output the final color value (C _(A) ) of the pixel by processing the alpha blending by determining the upper and lower layers for each pixel of the plurality of signals input through the plurality of OSD unit through the generated control signal Output stage, A second output step of selectively outputting any one of a color value of a background pixel and a pixel color value of a lower layer input through an input signal indicating whether the OSD is used in the background; The final color value C _(A) of the corresponding pixel output through the first output step through an input signal indicating whether the corresponding pixel belongs to the OSD region from the outside and the background pixel output through the second output step. A third output step of receiving a color value of or a pixel color value of the lower layer (OSD2) and selectively outputting any one of them; A color signal of a pixel output in the third output step and a pixel color value of a lower layer are input through a control signal for determining the area of the background, and one of the pixels is selectively output and the final color value is output to the display unit. And a fourth output step. The method of claim 5, And the characteristic information of the signal is at least one of transparency, color value, height information, and size information of each pixel.