KR19990019208A - Main screen subtitle display control device in sub screen display mode - Google Patents

Abstract

The present invention relates to a main screen caption display control apparatus in the sub-screen display mode, so that the caption of the main screen is not affected by the sub-screen when the PIP mode is set in a television equipped with the first and second tuners (16, 20). In order to detect the horizontal synchronization signal from the frame memory 42 in which the image data of the main screen converted by the main screen analog-digital conversion unit 40 is recorded in units of horizontal scan lines, A horizontal sync signal detection / counter 44 for counting, a caption filter unit 46 for detecting caption data from the digitally converted main screen image data, and applying the caption data to the controller; and based on a count result of the horizontal sync signal. In addition to controlling the detection process of the caption by the filter unit 46, the pixel missing and the scan line missing of the caption data are recorded in the image data recorded in the frame memory 42. Image data from the subtitle-reduced frame memory 42 and sub-screen analog-digital data from the control unit 12 for controlling the subtitle reduction process by the control unit, and the image switching unit 50 controlled under the control of the control unit 12. An image synthesizer 52 for synthesizing the sub-screen image data converted by the converter 48, and a CRT apparatus 30 by analog-converting the main screen / sub-screen image data synthesized by the image synthesizer 52; It comprises a digital-to-analog converting section 54 for transferring to the display process of the image.

Description

Main screen subtitle display control device in sub screen display mode

The present invention relates to a main screen subtitle display control apparatus in the sub-screen display mode, and more particularly, to reduce the subtitles to be displayed on the main screen when the sub-screen display is selected in the PIP mode in a two-tuner television. The present invention relates to a main screen subtitle display control device in a sub screen display mode in which subtitles and sub screens are properly displayed.

In general, a broadcasting station loads a caption signal on a video signal of a broadcast program in order to promptly notify a viewer of an announcement or emergency news of a broadcast program. According to the transmission of the caption signal, the caption signal generated independently at a predetermined position of the video signal of the broadcast program is edited by overlapping, and when the video signal edited with the caption signal is received by the television side, the CRT apparatus displays a video screen. The subtitle is reproduced and displayed at a predetermined position of.

Here, considering that only a single channel can be tuned and viewed in the case of a television employing a single tuner, the video signal of a channel tuned in one tuner by adopting a two-tuner to the television is a CRT device. The video signal of the channel tuned by the other tuner while being displayed on the main screen of is displayed in the form of a sub picture of an appropriate size at a predetermined position defined on the main screen of the CRT apparatus.

Therefore, in a two-tuner television, a video signal of a channel tuned by one tuner is watched through the main screen, while the other tuner is tuned to a sub-screen channel to be viewed or watched automatically. Applicable to the function.

Fig. 1A is a block diagram of a television adopting a general two-tuner system, in which reference numeral 10 denotes a remote control signal for selectively executing the overall functions of the television employing the two-tuner system. 12 indicates a control unit for controlling the execution of a function corresponding to a remote control signal transmitted from the remote control unit 10, and 14 indicates that tuning data for all channels that can be tuned in the corresponding television is stored. The tuning station data memory accessed by the control unit 12 is shown.

In Fig. 1A, 16 shows a first tuner for tuning the channel corresponding to the tuning data VT1 applied from the control unit 12, and 18 shows a channel tuned by the first tuner 16. A first image IF processing unit for IF-converting the video signal component by a predetermined intermediate frequency, 20 denotes a second tuner for performing channel tuning corresponding to the channel selection data VT2 applied by the control unit 12. And a numeral 22 denotes a second image IF processing unit which performs IF conversion processing on the image signal component of the channel tuned by the second tuner 20 by a predetermined intermediate frequency.

Also, reference numeral 24 denotes an image IF applied by the second image IF processing unit 22 in response to a PIP control signal PIP applied from the controller 12 when the PIP mode is set by the remote controller 10. A PIP processing unit for compressing a signal, for example, and processing it as a sub picture signal, and 26 denotes a timing matched to a switching signal (S / W) of the sub picture signal applied from the control unit 12 in the PIP mode. A PIP switching output section for switching and outputting the sub picture signal processed in 24).

28 is an image processed only by the image IF signal processed by the first image IF processor 18 so as to be reproduced to the CRT device 30 or the image processed by the first image IF processor 18 when the PIP mode is set. An image processing unit for mixing and processing the sub picture signal outputted from the PIP switching output unit 26 at a predetermined position of the IF signal and reproducing it to the CRT device 30 is shown.

According to the two-tuner television having the above-described configuration, if a specific channel number is designated by the remote controller 10 in the state that the PIP mode for displaying the sub screen is not set, the control unit 12 determines the channel number of the target station. The tuner data VT1 for the first tuner 16 is accessed from the tuner data memory 14 and applied to, for example, the first tuner 16, so that the video signal component of the channel tuned in the first tuner 16 is selected. One image IF processing unit 18 performs IF conversion processing, and the image processing unit 28 reproduces the R / G / B color components, and then the reproduced video signal is applied to the CRT device 30 for reproduction.

While the video signal of the channel tuned by the first tuner 16 is reproduced in the CRT device 30, the remote control signal for setting the PIP mode from the remote controller 10 and the channel number of the PIP mode are transmitted. In response, the control unit 12 accesses the tuning data VT2 corresponding to the channel number from the tuning data memory 14 and applies the tuning data VT2 to the second tuner 20 and to the PIP processing unit 24. The control signal PIP is applied. Accordingly, the image signal component of the channel tuned by the second tuner 20 is IF converted by the second image IF processor 22 and applied to the PIP processor 24, and the PIP processor 24 is The video IF signal applied by the second video IF processing unit 22 is compressed to a size of a sub picture and applied to the PIP switching output unit 26 side.

The PIP switching output unit 26 is timing-matched to the switching signal S / W of the sub-screen signal applied from the control unit 12 and outputs to the image processing unit 28. Accordingly, the image processing unit 28 ) Processes the video signal of the channel tuned in the first tuner 16 as a main screen signal, and processes the video signal of the channel tuned in the second tuner 20 as a sub picture signal. In the PIP mode, the CRT device 30 displays the main screen 30a and the sub screen 30b in the form illustrated in FIG. 1B.

The video signals of the channels tuned by the first tuner 16 and the second tuner 20 are positioned on the CRT device 30 by the button operation on the remote controller 10. Can be displayed as a change.

However, in the television employing the two-tuner method shown in FIG. 1A, the main screen 30a and the sub screen 30b of the CRT apparatus 30 are reproduced with the PIP mode set by the remote controller 10. If the subtitle is not displayed on the main screen 30a, the video displayed on the main screen 30a and the sub screen 30b can be appropriately reproduced, but setting the PIP mode as illustrated in FIG. 1C, for example. When the subtitle signal is mixed with the video signal displayed on the main screen 30a while the sub screen 30b is displayed on the main screen 30a of the CRT apparatus 30, a part of the subtitle signal is displayed. Is superimposed on the sub-screen 30b, which causes a disadvantage in that the recognition of the subtitle displayed on the main screen 30b is degraded in the PIP mode.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described situation of the related art, and the video signal to be displayed on the main screen in a state in which the PIP mode is set in the television employing the two-tuner method and the main screen and the sub screen are displayed on the CRT apparatus. It is an object of the present invention to provide a main screen subtitle display control apparatus in a sub picture display mode in which a subtitle signal is mixed in a subtitle display mode so as to reduce the size of the subtitle signal so as to eliminate the influence of the sub picture.

In order to achieve the above object, according to a preferred embodiment of the present invention, the main screen of the CRT apparatus is provided with the first and second tuners and the video signal of the channel tuned by the first and second tuners when the PIP mode is set. A television configured to display simultaneously on a sub screen and a sub screen, comprising: a frame memory in which video data of the main screen converted by a main screen analog-to-digital converter is recorded in units of horizontal scanning lines, and horizontally from the main screen video signal; A horizontal synchronous signal detection / counter for detecting and counting a synchronous signal, a caption filter unit for detecting caption data from the digitally converted main screen image data and applying the caption data to the control unit, and the caption filter based on a count result of the horizontal synchronous signal Control the detection process of the subtitles by means of subtitles and convert subtitle data from the image data recorded in the frame memory. A control unit for controlling the caption reduction process by the missing and scanning line leakage processing, the image data from the subtitle-reduced frame memory from the image switching unit controlled under the control and the sub-screen analog-digital conversion unit Sub-screen display including a video synthesizer for synthesizing the sub-screen image data, and a digital-analog converter for converting the main screen / sub-screen image data synthesized by the image synthesizer to a display process on the CRT apparatus. In the mode, a main screen subtitle display control device is provided.

Preferably, the caption filter unit includes a line data memory for temporarily activating and temporarily storing image data of a caption display position among the image data digitally converted by the main screen analog-digital conversion unit, and in the line data memory. A data slicer for slicing stored video data, and a caption character detection unit for detecting caption data from the data sliced by the data slicer, wherein the white level of the caption data is set from the white level of the main screen video signal. A white level reference value for separate extraction is set, and the data slicer slices the image data at the subtitle display position based on the white level reference value.

According to the main screen subtitle display control apparatus in the sub screen display mode according to the present invention having the above-described configuration, the PIP mode in which the video signal of the channel tuned by the first and second tuners is displayed on the main screen and the sub screen by the CRT apparatus. When the caption is detected by the caption filter unit, the subtitle data included in the main screen image data recorded in the frame memory is executed under the control of the control unit. By synthesizing with the screen image data, the subtitles of the main screen and the video of the sub screen are not mutually influenced in the PIP mode.

1A is a block diagram of a television adopting a general two-tuner system;

FIG. 1B is a view for explaining a subtitle display state on a main screen in a picture-in-picture (PIP) mode for displaying a sub screen in a television employing the two-tuner method shown in FIG. 1A;

FIG. 1C is a view for explaining a display state of a sub-screen and subtitles on the main screen in the PIP mode in the television employing the two-tuner method shown in FIG. 1A;

2 is a block diagram showing a main screen caption display control apparatus in a sub screen display mode according to the present invention;

3A to 3D are exemplary views illustrating the operation of the main screen subtitle display control apparatus in the sub screen display mode according to the present invention.

* Explanation of symbols for main parts of the drawings

10: remote control, 12: control unit,

16, 20: first and second tuners, 28: the image processing unit,

40: analog-to-digital converter, 42: frame memory,

44: horizontal sync signal detection / counter, 46: subtitle filter unit,

46a: line data memory, 46b: data slicer,

46c: caption character detection unit, 50: video switching unit,

52: image synthesizer, 54: digital-analog converter.

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

FIG. 2 is a block diagram showing a main screen caption display control apparatus in the sub-screen display mode according to the present invention. Reference numeral 40 denotes an image IF signal PIF1 provided by the first image IF processing unit 18 shown in FIG. 1A. ) Is an analog-to-digital conversion unit for sampling and digitally converting horizontal units, and 42 is a control of the control unit 12 including a control function of the overall operation of the main screen subtitle display control device in the sub-screen display mode according to the present invention. And a frame memory in which the digitally converted image data is stored and read in a form that matches the horizontal line position. 44 denotes a frame synchronous signal detected by the control unit 12 by detecting / counting a horizontal synchronization signal from the image IF signal PIF1. Represents a horizontal synchronous signal detection / counter provided to be applied to judging caption positions and reducing processing of caption characters.

In FIG. 2, reference numeral 46 denotes a caption filter unit which is activated at the display position of the caption character by the control unit 12 and detects captions from the image data digitally converted by the analog-digital conversion unit 40. The caption filter unit 46 includes a line data memory 46a in which image data of the digitally converted horizontal scan line unit is temporarily recorded. The line data memory 46a is illustrated in FIG. 3A. As described above, assuming that a subtitle is displayed between the nth horizontal scan line and the n + m horizontal scan line on the main screen 30a of the CRT apparatus 30, each horizontal scan line data is temporarily stored separately. It will have multiple line data registers or memory areas. In addition, the caption filter unit 46 performs image filtering (that is, caption data) temporarily stored in the line data memory 46a in units of horizontal scan lines by digital filtering and slicing by reference values. A data slicer 46b for extracting caption data is provided. The data slicer 46b detects edges of caption characters in units of horizontal scan lines at positions where captions are displayed in the form illustrated in FIG. 3B. Subsequently, level slicing is performed based on a predetermined white level reference value or a white level reference value applied from the controller 12 to remove the image data component of the background image from the contour data of the subtitle character. . In addition, the caption filter unit 46 detects a margin portion (see 't' in FIG. 3B) between the caption character and the caption character based on the caption contour data applied to the data slicer 46b to control the controller 12. Subtitle character detecting unit 46c applied to the subtitle character detecting unit 46c. In this case, the control unit 12 subtitles recorded in the frame memory 42 based on the detected margin part (see 't' in FIG. 3B). As a result of the pixel missing reading of the data, a control for reducing the size of the subtitle to be displayed on the main screen 30a of the CRT apparatus 30 as a whole is performed.

In addition, 48 indicates a sub picture signal analog-to-digital converter for digitally converting the sub picture signal provided from the PIP switching output unit 48 on a line basis, and 50 indicates an image switching signal SW provided from the control unit 12. And an image switching unit for switching and outputting main screen image data read out from the frame memory 42 and sub-screen image data read out from the analog-digital conversion unit 48, and 52 denotes the image switching unit. An image synthesizer for storing and reading the image signals of the main screen or the main screen and the sub screen provided through the unit 52 in units of horizontal scan lines, and synthesizing the synthesized image, wherein 54 is an image synthesized by the image synthesizer 52. A digital-analog converter for converting data into analog and applying the same to the image processor 28 illustrated in FIG. 1A is shown.

Next, the operation of the main screen subtitle display control apparatus in the sub screen display mode according to the present invention having the above-described configuration will be described in detail with reference to FIG. 3.

First, as described with reference to FIG. 1A, the PIP mode is set for the controller 12 from the remote controller 10, and the caption is displayed on the main screen 30a of the CRT device 30 in the form illustrated in FIG. 3A. In the case of processing the video signal to be displayed, the controller 12 sets an enable state for the size reduction process of the subtitles when the PIP mode is set, and in this state the sub-screen displayed on the CRT apparatus 30 ( The position of 30b) is a state recognized by the controller 12 programmatically.

In such a state, the horizontal synchronous signal detection / counter unit 44 detects and counts the horizontal synchronous signal from the image IF signal PIF1 provided by the one image IF processing unit 18, and counts the result. 12) is applied. Accordingly, the control unit 12 generates an address signal Add1 for recording image data in units of horizontal scan lines in the frame memory 42 based on the count result of the horizontal synchronization signal.

In addition, the image IF signal PIF1 is digitally converted in units of horizontal scan lines by the main screen analog-to-digital conversion unit 40, and the digitally converted image data is an address signal Add1 applied by the controller 12. Is stored in the frame memory 42 in a form that matches the position of the horizontal scan line.

In addition, the control unit 12 is defined programmatically in the main screen 30a on the CRT device 30 based on the count result of the horizontal synchronization signal applied from the horizontal synchronization signal detection / counter 44. When the count result of the nth horizontal scanning line of the subtitle position (nth horizontal scanning line-n + m horizontal scanning line in FIG. 3A) is input, it is enabled in the line data memory 46a of the subtitle filter unit 46. The signal EN is applied. That is, when the horizontal synchronous signal count result associated with the nth horizontal scan line at the subtitle display position is applied from the horizontal synchronous signal detection / counter 44, the control unit 12 enables the signal to the line data memory 46. The subtitle data of the image data digitally converted by the analog-digital conversion unit 40 is also applied to the line data memory 46a of the subtitle filter unit 46. The image data of the nth horizontal scanning line-the n + mth horizontal scanning line is sequentially recorded in a plurality of line data registers or memory areas constituting the line data memory 46a.

The image data of the nth horizontal scanning line-the n + mth horizontal scanning line recorded in the line data memory 46a is sequentially read and applied to the data slicer 46b so as to be previously set white level reference value or the control unit 12. Level slicing (refer to FIG. 3B) is applied to the caption character detection unit 46c by the white level reference value applied by the control panel, and the caption character detection unit 46c uses the data from the data applied by the data slicer 46b. The caption character data is detected in the form illustrated in FIG. 3C, and the margin portion t defined between the caption characters is determined based on the detected caption character data. That is, the caption displayed on the CRT device 30 generally has a predetermined margin portion (t) between the characters, and the data slicer 46b detects the main screen image detected between the caption characters and the caption characters. Only the subtitle character data is detected by removing the white level, and the blank part defined between the subtitle character and the subtitle character by the synthesis process of the entire horizontal scan line corresponding to the subtitle display position is detected. (t) can be detected.

Therefore, the control unit 12 is a state in which the subtitle is included in the main screen signal when, for example, the low-level data for the margin portion (t) between the subtitle characters detected by the subtitle character detection unit 46c is substantially applied at regular intervals. You will be judged.

Accordingly, the control unit 12 bases on the address signal Add1 set by the horizontal synchronous signal detection / counter 44 when the sub picture is included in the main screen signal and the display of the sub screen in the PIP mode is designated. The image data recorded in the frame memory 42 is executed to determine the location where the caption data is recorded and stored, and the pixel leakage read control in the horizontal direction and the appropriate number of horizontal scan line units are determined for the determined caption data. The read control signal R is applied to the frame memory 42 so that the size of the caption character is reduced by the omission process.

Accordingly, normal image read control of the main screen signal stored in the frame memory 42 is performed from the first horizontal scan line to the n-1 horizontal scan line, but from the nth horizontal scan line where the subtitle data is recorded. For the memory positions between the n + m horizontal scan lines, pixel missing processing is performed in the horizontal direction, and an appropriate number of horizontal scanning lines are read missing processing, thereby reducing the size of the subtitle character.

In this case, the control unit 12 actually removes the blanking portion of the main screen image displayed on the CRT apparatus 30 when the horizontal scanning line for the size reduction processing for the caption data is performed in the frame memory 42. In order to prevent occurrence, it is a matter of course that the horizontal scan line located above the n-th horizontal scan line can be controlled such that redundant reading is performed.

When the image data is read out in a form in which the size of the subtitle is reduced in the frame memory 42, the controller 12 initially applies a switching signal SW to the image switching unit 50 so that the frame memory can be read. While the image data read out at 50 is switched output, the sub picture data analog-digital converted by the sub picture signal analog-digital conversion unit 48 is controlled to be switched output corresponding to the display position of the sub picture.

Therefore, the main screen data (including the reduced processed subtitle data) and the sub picture data of one frame obtained by the switching output in the image switching unit 50 are sequentially recorded in the image synthesizing unit 52 serving as a video RAM, for example. 3D forms an image frame as shown in FIG. 3D, and the image data formed in the image synthesizer 52 is analog-converted through the digital-analog converter 54 and applied to the image processor 28. The sub screen 30b is displayed on the main screen 30a of the CRT apparatus 30, and the subtitles displayed on the main screen 30a are reduced in size, thereby eliminating the influence of the sub screen 30b. .

Meanwhile, the present invention is not limited to the above-described example, but when the subtitle is included on the main screen in the PIP mode set in the two-tuner television, the size of the subtitle is reduced to prevent mutual influence with the sub picture. Various modifications and changes can be made to realize the technical idea that can be realized.

As described above, according to the main screen subtitle display control apparatus in the sub-screen display mode according to the present invention, the sub-screen is displayed on the main screen in a state in which the sub-screen is displayed on the main screen by the PIP mode in a 2-tuner television. When the display is included, the size of the subtitle can be reduced to prevent mutual influence due to overlapping of the display position of the subtitle and the sub screen, thereby improving the recognition of the subtitle and limiting the display of the sub screen. Can also be significantly reduced.

Claims (3)

The first and second tuners 16 and 20 are provided with the main screen of the CRT device 30 and the sub picture signals of the channel tuned by the first and second tuners 16 and 20 when the PIP mode is set. In a television that is intended to be displayed simultaneously on the screen, A frame memory 42 in which the image data of the main screen converted by the main screen analog-digital conversion unit 40 is recorded in units of horizontal scan lines; A horizontal synchronous signal detection / counter 44 for detecting and counting a horizontal synchronous signal from the main screen video signal; A caption filter unit 46 for detecting caption data from the digitally converted main screen image data and applying the caption data to the controller; On the basis of the counting result of the horizontal synchronization signal, the caption filter unit 46 controls the caption detection process, and also the pixel drop and scan line drop processing of the caption data in the image data recorded in the frame memory 42. A control unit 12 for controlling subtitle reduction processing by Image data from the subtitle-reduced frame memory 42 from the image switching unit 50 controlled under the control of the control unit 12 and sub-screen image data converted by the sub-screen analog-digital conversion unit 48. Image synthesizing unit 52 for synthesizing And a digital-to-analog converter 54 for converting the main screen / sub-screen image data synthesized by the image synthesizer 52 to a display process on the CRT device 30. Main screen subtitle display control device in screen display mode. The caption filter unit 46 of claim 1, wherein the caption filter unit 46 is activated under the control of the control unit 12 to control the image data of the caption display position among the image data digitally converted by the main screen analog-digital conversion unit 40. Subtitles for detecting caption data from the line data memory 46a for temporary storage, the data slicer 46b for slicing the image data stored in the line data memory 46a, and the data sliced by the data slicer 46b. Main screen subtitle display control device in the sub-screen display mode, characterized in that the character detection unit (46c). 3. The data slicer 46b is set with a white level reference value for separating and extracting the white level of the caption data from the white level of the main screen video signal, and the data slicer 46b has the white level reference value. The main screen subtitle display control apparatus in the sub-screen display mode, characterized in that for slicing the image data of the subtitle display position based on.