JPH10178620A - Character data transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a character data transmission system which simplifies an algorithm that detects a character signal. SOLUTION: When a character data inserting means 11 of a sending means, etc., superimposes a character signal on a video signal, prescribed attributes of character data that corresponds to the character signal, e.g. a symbol signal that represents the position, size, etc., of the character data are superimposed just before and just after the character signal. When a character data recognizing means 23 of a receiving means, etc., refers to such a symbol signal, it can simplify an algorithm to detect the character signal by fixing a parameter, etc., in the algorithm to detect the character signal. For instance, when a symbol signal represents the position of character data, a parameter, etc., that regulates a segmenting position of a video signal in the algorithm can be fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a character data transmission system capable of simultaneously transmitting a video signal and character data.

[0002]

2. Description of the Related Art The technology of inserting character data into a video signal of the NTSC system or the like and reproducing it on the receiving side has been developed as a means for adding value to information transmitted by television broadcasting or the like. . An example of such a technique will be described below. On the transmitting side, the video signal is converted into a digital signal at a white level and a black level by a predetermined means.
A character signal corresponding to character data is superimposed. On the reproduced video image screen, the character signal is displayed as a temporally continuous column of the white level and the black level. When a television receiver is used as the reproducing means, the vertical scanning frequency is 60 Hz, so that a character signal can be transmitted and displayed at 60 bits / second.

In the transmitting means, the position where the above-mentioned white level and black level are displayed on the reproduced video image screen is controlled in relation to the setting of the signal processing parameters used when inserting the character data. be able to. The above-mentioned white level and black level are read by optical means and detected as digital signals. Then, the character data inserted into the video signal is reproduced from the digital signal by a predetermined means.

[0004] A character data transmission system is also used in which a character signal superimposed on a video signal is detected by a signal processing system such as a receiving means, and character data is reproduced from the detected character signal. An example using such a reproducing method will be described below. The transmitting side inserts character data into the video signal by superimposing a character signal corresponding to the character data to be transmitted on the video signal. On the receiving side, the received video signal is supplied to video output means such as a video monitor and character data recognition means for recognizing character data. The video output means reproduces a video video from the supplied video signal. On the other hand, the character data recognizing means reproduces the inserted character data from the supplied video signal as described below. The reproduced character data is output by a predetermined output unit such as a video output unit such as a video monitor described above.

[0005] The video signal supplied to the character data recognizing means is temporarily held by predetermined means provided in the character data recognizing means. On the other hand, all predetermined signal patterns used as character signals are stored by means such as a ROM. By comparing a fragment of a video signal cut out from the temporarily held video signal as described later with a signal pattern used as a character signal stored as described above, the video The character signal superimposed on the signal is detected. Character data is reproduced from the detected character signal.

[0006]

In the conventional method as described above, the following problem occurs when the character data recognizing means detects a character signal. That is, the video signal on which the character signal is superimposed on the transmitting side includes a character signal having an unknown data length at an unknown position in the video signal when supplied to the character data recognizing means.
FIG. 6 shows an example of character data reproduced from a character signal having an unknown data length at an unknown position in the video signal when the character data output means is the above-described video output means. . Such character data is displayed at an unknown position on the effective screen in an unknown size.

In order to detect a character signal having an unknown data length at an unknown position in a video signal as described above, the character data of the character data is extracted from the temporarily stored one-frame video signal. With all regions that can be the starting points as starting points, fragments of all lengths that can be the data length corresponding to the size of the character data must be cut out, and the presence or absence of a character signal must be determined for each of these fragments.

[0008] In the algorithm for performing such detection, it is necessary to treat parameters or the like defining the cutout position and cutout length of the video signal as variables. For this reason, the algorithm for detection becomes complicated.

Accordingly, it is an object of the present invention to provide a character data transmission system which simplifies an algorithm for detecting a character signal.

[0010]

According to a first aspect of the present invention, there is provided a transmitting means having character data inserting means for inserting character data into a video signal by superimposing a character signal corresponding to character data on a video signal. In a character data transmission system comprising a reproducing means and a receiving means or a reproducing means having a character data recognizing means for detecting a character signal from a received video signal and reproducing character data from the detected character signal, The means superimposes a symbol signal expressing a predetermined attribute of character data immediately before and immediately after the character signal when superimposing the character signal on the video signal, and the character data recognition means refers to the symbol signal. A character data transmission system for detecting a character signal.

By using the above means, it is possible to fix parameters in an algorithm for detecting a character signal by referring to a symbol signal superimposed immediately before and after the character signal.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. FIG. 1 is a block diagram showing the overall configuration of a character data transmission system to which the present invention is applied. In the transmitting means 1, the video signal and the character data to be transmitted are supplied to character data inserting means 11 such as a character generator. The character data inserting means 11 generates a character signal corresponding to the supplied character data, and superimposes the character signal on the video signal. At this time, a predetermined symbol signal is superimposed immediately before and after the character signal. The video signal on which the character signal and the symbol signal are superimposed is supplied to the video signal transmitting means 12. Video signal transmitting means 1
2 modulates and amplifies the supplied video signal and transmits it via the antenna 13.

On the other hand, in the receiving means 2, the video signal is supplied by the video signal receiving means 22 via the antenna 21. The video signal receiving unit 22 demodulates the supplied video signal, and supplies the demodulated video signal to the character data recognizing unit 23 and a video image output unit 24 such as a video monitor. Character data recognition means 2
Reference numeral 3 detects a superimposed character signal from the supplied video signal, as described later. When detecting a character signal, as described above, the character data insertion means 11 on the transmitting side is used.
Refers to a symbol signal superimposed immediately before and after the character signal.

The character data recognizing means 23 reproduces the corresponding character data from the detected character signal and supplies it to a predetermined display means. The display means displays the supplied character data. On the other hand, the video image output means 24 reproduces the supplied video signal and outputs a video image. In this embodiment, the predetermined display means for displaying the above-mentioned character data is the video image output means 24. Therefore, the reproduced character data is displayed on the video image output by the video image output means 24.

The character data recognizing means 23 will be described in detail with reference to FIG. Character data recognition means 23
Comprises a video signal storage means 31, a microcomputer 32 for comprehensively controlling the operation of the character data recognition means, a character signal storage means 33, and a video signal comparison means.

As described above, the video signal supplied from the video signal receiving means 22 is temporarily stored in the video signal storage means 31 for a predetermined data amount, for example, for each frame. On the other hand, the character signal storage unit 33 stores all signal patterns that can be superimposed on the video signal as character signals by the character data insertion unit 11.

A microcomputer 32 for comprehensively controlling the operation of the character data recognizing means generates a signal for controlling the clipping of the video signal, and supplies the signal for controlling the clipping of the generated video signal to the video signal storage means 31. . A microcomputer 32 for comprehensively controlling the operation of the character data recognition means.
Controls the timing of the character signal detection operation performed by the video signal comparison means 34. Further, the microcomputer 32, which comprehensively controls the operation of the character data recognizing means, receives the character signal detected from the video signal comparing means 34 and reproduces character data from the received character signal.

The video signal storage means 31 operates in accordance with the above-mentioned signal for controlling the extraction of the video signal. That is, a video signal fragment is cut out from the temporarily held video signal in accordance with a cut-out position, a cut-out length, and other cut-out conditions specified by a signal for controlling the cut-out of the video signal, and supplied to the video signal comparing means 34. The video signal comparing means 34 is supplied with a signal pattern used as a character signal at a predetermined timing from the character signal storage means 33 described above.

The video signal comparing means 34 refers to the signal pattern used as the character signal supplied from the character signal storing means 33, and is included in the video signal fragment supplied from the video signal storing means 31. Character signal is detected. As described above, this detection operation follows a command from the microcomputer 32 that comprehensively controls the operation of the character data recognition means. The detected character signal is supplied to a microcomputer 32 that comprehensively controls the operation of the character data recognition means.

As described above, the character data recognition means 23
Is detected by the character data insertion means 11 on the transmission side with reference to the symbol signal superimposed immediately before and after the character signal. A method for detecting such a character signal will be described. The microcomputer 32 that comprehensively controls the operation of the above-described character data recognition means operates according to an algorithm for detecting a character signal. As described above, the algorithm for detecting the character signal includes the parameters that define the cutout position and cutout length of the video signal.

If the position of the character signal in the video signal and the data length of the character signal are unknown, these parameters and the like must be treated as variables. For this reason, the above-described problem has occurred. However, in the present invention, the position of the character signal in the video signal, the data length of the character signal, and the like are known by referring to attributes such as the size and position of the character data represented by the above-described symbol signal. Therefore, fixed values can be set for parameters of an algorithm for performing detection.

A microcomputer 32 that comprehensively controls the operation of the character data recognizing means in accordance with the algorithm in which the fixed values are set in the parameters and the like as described above issues a signal such as issuing a signal for controlling the extraction of a video signal. Control.

The above-mentioned symbol signal is supplied to video image output means 2
4 is an example of character data to be displayed when the position of character data on the effective screen of the video image to be output is expressed, that is, when the position at which the character is to be displayed is previously notified to the character recognizing means 23. Is shown in FIG.
In FIG. 3, an area for displaying a character (a square for three characters)
Are marked with black square symbols at the upper left and lower right.
The black square symbols indicate the start position and the end position of the area for displaying the characters (the meshes for three characters).

The black square symbol corresponds to the symbol signal superimposed before and after the character signal in the video signal. First, if a symbol signal corresponding to this black square can be detected from a video signal of one frame constituting a video image, processing for recognizing the inserted character data is performed by using the symbol signal as a starting position. What is necessary is just to perform it about the area | region where an end position is shown. As the symbol signal superimposed before and after the character signal in the video signal, various signals can be used in addition to the signal corresponding to the black square symbol used in this example.

That is, in this case, it is sufficient to detect the character signal in a situation where the position of the character signal in the video signal is fixed. For this reason, in an algorithm for detecting a character signal, it is possible to fix a parameter or the like defining a cutout position of a video signal.

If the above-mentioned symbol signal represents the size of character data on the effective screen of the video image output by the video image output means 24, the data length of the character signal in the video signal In this situation, it is only necessary to detect the character signal. For this reason, in an algorithm for detecting a character signal, it is possible to fix a parameter or the like defining a cutout length of a video signal.

Further, when the above-mentioned symbol signal represents both the position and the size of the character data on the effective screen of the video image output by the video image output means 24, the character data to be displayed is An example is shown in FIG. In FIG. 4, black square symbols of the size of one cell are displayed on the left and right sides of the area for displaying characters (cells for three characters). The black square symbol indicates the position of the area for displaying characters (cells for three characters).
In this example, the size of such a black square indicates the size of the displayed character (the size of a square for one character).

This symbol corresponds to the symbol signal superimposed before and after the character signal in the video signal. First, if a symbol signal corresponding to this black square can be detected from the video signal for one frame constituting the video image, the process for recognizing the inserted character data is performed by using the symbol signal to determine the start position. If the region where the end position is indicated is divided into the size indicated by the symbol signal, that is, the size of the character indicated by the black square symbol in FIG. Good. As the symbol signal superimposed before and after the character signal in the video signal, various signals can be used in addition to the signal corresponding to the black square symbol used in this example.

That is, in this case, it is sufficient to detect a character signal in a situation where the position of the character signal in the video signal and the data length of the character signal are fixed. For this reason, in an algorithm for detecting a character signal, it is possible to fix parameters and the like that define a cutout position and a cutout length of a video signal.

In the above-described example shown in FIGS. 3 and 4, the case where all the displayed character strings have the same size has been described, but the sizes of the characters included in the displayed character strings are different. In this case, the present invention can be applied. However, if the symbol signal expresses both the position and the size of the character data, the symbol signal needs to be superimposed at the position where the character size changes in the displayed character string.

In one embodiment of the present invention, as described above with reference to FIG. 1, character data insertion means 11 for inserting character data into a video signal is included in transmission means 1. However, the video signal recording means for recording a video signal on a recording medium such as a magnetic tape is provided with the same character data insertion means as the character data insertion means 11, so that it has a function of inserting character data at the time of video signal reproduction. The present invention can be applied to a video signal recording / reproducing system including a video signal recording unit.

FIG. 5 shows the overall configuration of an example of such a recording / reproducing system. In the recording means 3,
A character data insertion unit 61 similar to the character data insertion unit 11 of FIG. 1 is provided. The character data insertion means 61 is supplied with a video signal to be recorded and character data to be inserted. The character data inserting means 61 generates a character signal corresponding to the supplied character data, and superimposes the character signal on the video signal. At this time, similar to the above-described embodiment of the present invention, a symbol signal representing a predetermined attribute of character data is superimposed immediately before and after the character signal.

The video signal on which the character signal and the symbol signal are superimposed is supplied to the video signal recording means 62.
The video signal recording means 62 performs predetermined signal processing on the supplied video signal and converts the signal into a recording signal. And
The recording signal is supplied to a video signal recording medium 63 such as a magnetic tape. The video signal recording medium 63 records the supplied recording signal.

On the other hand, in the reproducing means 4, a recording signal recorded on the video signal recording medium 63 is supplied to the video signal reproducing means 72 by a predetermined means. The video signal reproducing means 72 converts the supplied recording signal into an NTS
The video signal is converted into a format of a video signal such as the C system, and the video signal is supplied to a character data recognition unit 73 similar to the character data recognition unit 23 in FIG. The character data recognizing means 73 reproduces the inserted character data from the supplied video signal. On the other hand, the video image output means 74 reproduces the supplied video signal and outputs a video image.

[0035]

As described above, according to the present invention, the character data corresponding to the character data is superimposed, so that the character data inserting means in the transmitting means for inserting the character data into the video signal, etc. When the character signal is superimposed, a predetermined attribute of the character data to be inserted, particularly a symbol signal representing the position or size of the character data, is superimposed immediately before and immediately after the character signal, and is included in the receiving means and the like. In the character data recognizing means, a character signal is detected with reference to the above-mentioned symbol signal.

By referring to the attribute of the character data represented by the above-mentioned symbol signal, in particular, the symbol signal representing the position or size of the character data, the position of the character signal in the video signal or the data of the character signal is referred to. Since the length is known, it is possible to fix a parameter or the like, which is included in the algorithm for detecting the character signal, and specifies the cutout position or cutout length of the video signal. Therefore, in the algorithm for detecting a character signal, the complexity caused by treating such parameters and the like as variables is eliminated, and the detection of the character signal can be performed according to a simpler algorithm.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of a part of the receiving means in more detail in one embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating an example of character data to be displayed when a symbol signal represents a position of character data in one embodiment of the present invention.

FIG. 4 is a schematic diagram showing an example of character data to be displayed when a symbol signal represents the position and data length of character data in one embodiment of the present invention.

FIG. 5 is a block diagram showing an overall configuration of another embodiment of the present invention.

FIG. 6 is a schematic diagram illustrating an example of character data of an unknown size existing at an unknown position in a conventional character data transmission system.

[Explanation of symbols]

11 ... character data insertion means, 23 ... character data recognition means, 24 ... video image output means, 31 ...
Video signal storage means, 32: microcomputer for comprehensively controlling the operation of character data recognition means, 33: character signal storage means, 34: video signal comparison means, 61 ...
Character data insertion means, 62 ... video signal recording means,
63 ... video signal recording medium, 72 ... video signal reproducing means, 73 ... character data recognition means, 74 ...
Video image output means

Claims (3)

[Claims] 1. A transmitting means or a reproducing means having character data inserting means for inserting the character data into the video signal by superimposing a character signal corresponding to the character data on the video signal, and In a character data transmission system comprising: a receiving unit or a reproducing unit having a character data recognizing unit that detects the character signal and reproduces character data from the detected character signal, the character signal superimposing unit includes: When superimposing the character signal, a symbol signal expressing a predetermined attribute of the character data is superimposed immediately before and immediately after the character signal, and the character data recognition unit refers to the symbol signal. A character data transmission system for detecting the character signal. 2. The character data transmission system according to claim 1, wherein the predetermined attribute of the character data represented by the symbol signal is a position of the character data in the video signal. 3. The character data transmission system according to claim 1, wherein the predetermined attribute of the character data represented by the symbol signal is a size of the character data.