JP2001292459A - Video signal conversion, transmission method and system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convert a video signal of 720p/30 Hz (4:2:2p) (scanning line number 720, 30 Hz noninterlace scanning system) into a video signal of 480i/60 Hz (4:2:2i) (scanning line number 480, 60 Hz interlace scanning system). SOLUTION: A luminance component and a color difference component required for the 480p/30 Hz system are extracted from a luminance component and a color difference component for the 720p/30 Hz system, the extracted luminance component and color difference component are frequency-converted and multiplexed to generate a video signal of the 480p/30 Hz (4:2:2p) system, the noninterlace scanning system of the generated video signal is converted into the interface system to generate a video signal according to the 480i/60 Hz (4:2:2i) system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal transmission technique, and more particularly to a video signal of 720p / 30 Hz (horizontal 1280 pixels, vertical 720 pixels, 30 Hz progressive scanning method) corresponding to a video signal of 480i / 60 Hz (horizontal 720 pixels). ,
The present invention relates to a technology for converting and transmitting a signal format equivalent to a vertical 480 pixel, 60 Hz interlaced scanning method).

[0002]

2. Description of the Related Art In recent years, a number of television systems have been proposed along with higher image quality. Of these proposed signal formats, the one that is becoming standardized is 720
There is a p / 30 Hz system. The 720p / 30 Hz system is a progressive scanning system with 720 scanning lines and 30 Hz, and has a high affinity for movies, and thus has the potential for widespread use.

[0003]

[Problem to be solved] However, 720p / 3
The 0 Hz system is still in the process of being standardized, and even if it is standardized, it will take time for the infrastructure of the 720p / 30 Hz system to be ready. Against this background, 720p / 30
There has been a demand for a technology that can handle a video signal of the Hz system by using existing high quality infrastructure while making use of its inherent high image quality.

Accordingly, the present invention has been made in view of the above problems, and has as its object to solve the above problems.
While taking advantage of the inherent high image quality, 720p /
The video signal of the 30 Hz system (720 scanning lines, 30 Hz sequential scanning system) is used for converting the video signal to an infrastructure 4 already in place.
It is an object of the present invention to provide a technology of converting the data into an 80i / 60 Hz system (480 scanning lines, 60 Hz interlace system) and transmitting the converted data.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for converting a video signal, which comprises converting a luminance component of 720p / 30Hz system to a luminance component required for 480p / 30Hz system and 480p / 30Hz system. Extracting a horizontal high-frequency component and a vertical high-frequency component that are equal to or higher than the luminance component required for the system;
Extracting a chrominance component required for the 80p / 30Hz (4: 2: 0p) method, frequency-converting the extracted horizontal high-frequency component and vertical high-frequency component of the luminance, and multiplexing with the extracted color difference component 480p / 30Hz (4: 2: 2
generating a color difference component of the p) type; 480 p / 30
The 480p / 30Hz (4: 4) comprising a luminance component required for the Hz system and a color difference component in which the luminance component is multiplexed.
A video signal equivalent to the 2: 2p) system is converted from a progressive scanning system to an interlaced system, and is converted to 480i / 60 Hz (4: 2p).
2: 2i) generating a video signal equivalent to the system.

480p / 30Hz (4: 2: 2p)
Video signal equivalent to the 480i / 60Hz (4: 2: 2
i) The step of converting into a video signal equivalent to the system is 480p /
It is preferable that the step of dividing a scanning line of one field into two interlaced fields in a video signal corresponding to the 30 Hz (4: 2: 2p) system.

It is another object of the present invention to provide a method for converting a video signal, wherein the method is 480i / 60Hz (4: 2: 2i).
A video signal equivalent to the system is converted from the interlace system to the progressive scanning system, and 480p / 30Hz (4: 2: 2p)
Converting to a video signal equivalent to the standard, 480p / 30
Extracting the components corresponding to the horizontal high-frequency component and the vertical high-frequency component of the luminance from the color difference components of the Hz (4: 2: 2p) system, and performing frequency conversion; 480p / 30H for high frequency component and vertical high frequency component
generating a luminance component equivalent to 720p / 30 Hz by adding the luminance component to the z-system luminance component.

[0008] Incidentally, 480i / 60Hz (4: 2: 2i)
Video signal equivalent to the 480p / 30Hz (4: 2: 2
p) The step of converting to a video signal equivalent to the method is 480i /
Preferably, the process is a step of combining two interlaced fields in a video signal equivalent to the 60 Hz (4: 2: 2i) scheme to form one progressive scanning field.

[0009] The horizontal high-frequency component and the vertical high-frequency component of the extracted luminance are 480p / 30Hz (4: 2: 2).
p) The bandwidth of the color difference signal in the system and 480p / 30H
It preferably corresponds to the difference from the bandwidth of the color difference signal in the z (4: 2: 0p) system.

[0010] Also, identification information indicating that the luminance is multiplexed is embedded in the horizontal high-frequency component and / or the vertical high-frequency component of the luminance multiplexed on the color difference signal, or
It is preferable to embed identification information indicating multiplexing in the luminance signal.

An object of the present invention is to provide a method of transmitting a video signal.
A luminance component required for the 80p / 30 Hz system;
Extracting a horizontal high-frequency component and a vertical high-frequency component equal to or higher than a luminance component required for the 0p / 30 Hz method; 720
480p / 30Hz from color difference component of p / 30Hz system
(4: 2: 0p) extracting a chrominance component required for the method, frequency-converting the extracted horizontal high-frequency component and vertical high-frequency component, and multiplexing the extracted luminance component with the extracted chrominance component. / 30 Hz (4: 2: 2p) color difference component generation step, and the extracted 480p / 30H
z luminance component and the generated 480p / 30Hz
(4: 2: 2p) color difference components are combined, and 480p
Generating a video signal equivalent to the / 30 Hz (4: 2: 2p) system; and 480p / 30 Hz (4: 2: 2p).
Converting a video signal equivalent to the standard system from a progressive scanning system to an interlace system, generating a video signal equivalent to the 480i / 60 Hz (4: 2: 2i) system, and transmitting the video signal. Is achieved by the following transmission method.

The transmitted 480i / 60Hz
A video signal equivalent to the (4: 2: 2i) system is converted from the interlace system to the progressive scanning system, and is converted to 480p / 30Hz.
(4: 2: 2p) method of converting to a video signal equivalent to the method, and, from the 480p / 30 Hz (4: 2: 2p) method of color difference component, a component corresponding to a horizontal high-frequency component and a vertical high-frequency component of luminance. Extracting and frequency converting; and cutting out components corresponding to the horizontal high-frequency component and the vertical high-frequency component of luminance from the transmitted 480p / 30 Hz (4: 2: 2p) color difference component, 480p / 30Hz (4:
2: 0p) color difference component, and adding the horizontal and vertical high frequency components of the frequency-converted and returned luminance to the 480p / 30 Hz luminance component to obtain 720
generating a luminance component corresponding to p / 30 Hz.

The extracted horizontal and high frequency components of the luminance are 480 p / 30 Hz (4: 2: 2
p) The bandwidth of the color difference signal in the system and 480p / 30H
It preferably corresponds to the difference from the bandwidth of the color difference signal in the z (4: 2: 0p) system.

Also, identification information indicating that the luminance is multiplexed is embedded in the horizontal high-frequency component and / or the vertical high-frequency component of the luminance multiplexed on the chrominance signal, and the identification information is encoded on the receiving side. By detecting, to distinguish the multiplexed video signal and the non-multiplexed video signal on the receiving side, or embedding identification information indicating that the multiplexed in the luminance signal, the receiving side said It is preferable to distinguish the multiplexed video signal and the non-multiplexed video signal on the receiving side by detecting the identification information.

An object of the present invention is to provide an encoder for a video signal, in which a luminance component of a 720p / 30 Hz system is calculated from a luminance component.
A luminance component required for the 480p / 30 Hz system,
First extraction means for extracting a horizontal high-frequency component and a vertical high-frequency component that are higher than the luminance component required for the 80p / 30 Hz method, and 480 pixels from the 720p / 30 Hz color difference component.
a second extracting means for extracting a color difference component required for the p / 30 Hz (4: 2: 0p) method, and a frequency conversion of the extracted horizontal high-frequency component and vertical high-frequency component of the luminance, and the extraction. Multiplexed to the color difference component, 480p / 30Hz (4:
Means for generating a color difference component of the 2: 2p) method,
480p / 30Hz composed of a luminance component required for the / 30Hz system and a color difference component obtained by multiplexing the luminance components.
A video signal equivalent to the (4: 2: 2p) system is converted from a progressive scanning system to an interlaced system and converted to 480i / 60 Hz.
Means for generating a video signal equivalent to the (4: 2: 2i) system.

The first extracting means is 480p / 3
Horizontal high-frequency component and vertical high-frequency component of luminance corresponding to the difference between the bandwidth of the chrominance signal in the 0 Hz (4: 2: 2p) system and the bandwidth of the chrominance signal in the 480p / 30 Hz (4: 2: 0p) system Is preferably extracted.

Also, means for embedding identification information indicating that the luminance is multiplexed in the horizontal high-frequency component and / or the vertical high-frequency component of the luminance multiplexed on the chrominance signal, or multiplexed. It is preferable to have a means for embedding identification information indicating that there is in the luminance signal.

An object of the present invention is to provide a decoder for a video signal, which converts a video signal corresponding to a 480i / 60 Hz (4: 2: 2i) system from an interlaced system to a progressive scanning system to 480p / 30Hz. Means for converting to a video signal equivalent to the (4: 2: 2p) system, and 480p / 30Hz
Extracting means for extracting components corresponding to the horizontal high-frequency component and the vertical high-frequency component of the luminance from the color difference components of the (4: 2: 2p) method, and performing frequency conversion on the extracted components to perform 480p / 3
A conversion means for converting the horizontal high-frequency component and the vertical high-frequency component of a luminance of 0 Hz (4: 2: 0p) or higher into a high-frequency component and a high-frequency component of a high frequency;
It is added to the luminance component of the p / 30 Hz method, and 720p / 30
And a generating means for generating a luminance component corresponding to Hz.

Further, a detecting means for detecting the identification information embedded in the color difference component, and when the identification information is detected by the detecting means, the extracting means performs an extraction process, and the identification information is detected. If not, the extraction means is configured not to perform the extraction processing,
Alternatively, detecting means for detecting the identification information embedded in the luminance component, and when the identification information is detected by the detection means, the extracting means performs an extraction process, and when the identification information is not detected. Preferably, the extracting means is configured not to perform the extracting process.

[0020]

Embodiments of the present invention will be described with reference to the drawings. First, a multiplexing method according to the present embodiment will be described. FIG. 1 is a diagram for explaining a multiplexing method according to the present embodiment.

Generally, 720p / 30 Hz (4: 2: 2
The output of the luminance component of the video signal of the p) method is horizontal 1280.
Pixels, 720 vertical pixels. Here, the above 720p
FIG. 1 shows a luminance component of a video signal of / 30 Hz (4: 2: 2p). A rectangular area surrounded by horizontal 1280 Lpw and vertical 720 Lph is a luminance component of 720p / 30 Hz. And 720Lpw horizontal and 480Lph vertical
A rectangular area surrounded by 480i / 60Hz (4:
2: 2i) method (480p / 30Hz (4: 2: 2i)
This is the luminance component required by the standard.

By the way, the demand for high resolution in a video is only increasing, and it is advantageous to have information of many luminance components in a transmission signal. However, 720p /
30Hz system infrastructure is not available at the moment,
The video signal of the 720p / 30 Hz system cannot be used. On the other hand, the 480i / 60 Hz system is a mainstream signal system at present, and the infrastructure is sufficiently developed.

Further, the human eye has a characteristic that it is difficult for the human eye to perceive even an image in which the high-frequency components of the color components are slightly lost.

Therefore, 720p / 30 Hz (4: 2: 2
720p / 30Hz in order to make use of the luminance component of the p) system and convert it to a signal format of the 480i / 60Hz (4: 2: 2i) system in which the infrastructure is sufficiently arranged so that transmission is possible.
The following signal processing is performed on the signal of the (4: 2: 2p) system. (1) In a 720p / 30Hz (4: 2: 2p) luminance signal, a luminance component (equivalent to a 480p / 30Hz (4: 2: 2p) method) which is horizontal 720 Lpw or less and vertical 480 Lph or less is cut out. (2) In a 720p / 30 Hz (4: 2: 2p) luminance signal, a vertical high-frequency component (VH) of 360 Lpw or less in the horizontal direction and 480 Lph or more in the vertical direction, and a horizontal high-frequency component of 720 Lpw or more in the 720p / 30 Lpw or more range.
A horizontal high-frequency component (HH) of 080 Lpw or less and a vertical of 240 Lph or less is cut out. (3) From the 720p / 30 Hz (4: 2: 2p) color difference signal, the color difference components Cb and Cr (horizontal 360 Lpw or less and vertical 240 Lph or less) corresponding to the 480p / 30 Hz (4: 2: 0p) system are cut out. (4) The frequency of the cut vertical high frequency component (VH) and horizontal high frequency component (HH) is converted, and the frequency-converted vertical high frequency component (VH) and horizontal high frequency component (HH) are converted into a color signal C.
Superimposed on the vertical high frequencies of b and Cr.

(5) The signal generated through the steps (1) to (4) (encoding) has a 480p / 30 Hz (4: 2: 2p) signal format. . Therefore, a signal (480p / 30 Hz (4: 2: 2p) signal) generated through the above process is converted into a scanning line, that is, as shown in FIG. 480i / 60Hz by dividing into two interlaced fields
(4: 2: 2i) format. Note that the image signal encoded as described above is decoded by performing the above-described reverse processing.

Next, an apparatus (encoder) for realizing the above-described multiplexing method will be described. FIG. 3 is a block diagram of an encoder that implements the multiplexing method according to the present embodiment.

In FIG. 3, reference numeral 21 denotes 720p / 30 Hz (4:
2: 2p), a low-pass filter that cuts components of 720 Lph or more in the luminance signal, 22 a low-pass filter that cuts components of 1080 Lpw or more from the output of the low-pass filter 21, and 23 a low-pass filter 2
2, a low-pass filter that cuts a component of 360 Lpw or more horizontally from the output of 2, a low-pass filter 24 that cuts a component of 480 Lph or more from the output of the low-pass filter 23, and 25 adds the output of the low-pass filter 23 and the output of the low-pass filter 24. The adder 26 is a vertical frequency converter for shifting the output of the adder 25 to the lower frequency side.

Reference numeral 27 denotes a low-pass filter that cuts components of horizontal 720 Lpw or more from the output of the low-pass filter 22, and reference numeral 28 denotes a low-pass filter that cuts components of vertical 480 Lph or more from the output of the low-pass filter 27.

An adder 29 adds the output of the low-pass filter 22 and the output of the low-pass filter 27.
0 is a low-pass filter that cuts a component of 240 Lph or more from the output of the adder 29, 31 is a horizontal frequency converter that shifts the output of the low-pass filter 30 to the horizontal lower frequency side, and 32 is the output of the horizontal frequency converter 31. Is a vertical frequency conversion unit that shifts.

33 is 720p / 30 Hz (4:
2: 2p) is a low-pass filter that cuts components of 360 Lpw or more horizontally from the color difference signal Cb, and 34 is a low-pass filter that cuts components of 240 Lph or more from the output of the low-pass filter 33.

35 is 720p / 30Hz (4:
2: 2p) is a low-pass filter that cuts components of 360 Lpw or more horizontally from the color difference signal Cr, and 36 is a low-pass filter that cuts components of 240 Lph or more from the output of the low-pass filter 35.

Reference numeral 37 denotes a downconverter for downconverting the output signal of the vertical frequency converter 26 from a 720p / 30 Hz signal to a 480p / 30 Hz signal by thinning out scanning lines and horizontal pixels. 38
Represents the output signal of the low-pass filter 28 as 720p / 30
By thinning out the scanning lines and horizontal pixels from the signal of the Hz system,
This is a down-converter that down-converts to a signal of the 480p / 30 Hz system. 39 is a vertical frequency converter 32
Is a down-converter for thinning out the scanning lines and horizontal pixels from the 720p / 30 Hz type signal and down-converting the output signal into a 480 p / 30 Hz type signal. Numeral 40 designates the output signal of the low-pass filter 34 as 720
This is a down converter that thins out scanning lines and horizontal pixels from a signal of the p / 30 Hz system to down convert to a signal of the 480 p / 30 Hz system. Reference numeral 41 denotes a signal of 480 p / 30 which is obtained by thinning the output signal of the low-pass filter 36 from the 720p / 30 Hz system signal by scanning lines and horizontal pixels.
This is a down-converter that down-converts to a signal of the Hz system.

An adder 42 adds the output of the downconverter 37 and the output of the downconverter 40.
3 is the output of the down converter 39 and the down converter 4
This is an adder for adding the output of the first and the second. And 44
The output of the adder 42, the output of the down converter 38,
The multiplexing circuit multiplexes the output of the adder 43.

45 is 480p / 30Hz (4: 2: 2
The scanning line of the signal of the p) system is converted as shown in FIG.
This is a scanning line conversion unit that converts the signal into an 80i / 60 Hz (4: 2: 2i) signal.

In such a configuration, the encoder operates as follows. First, 720p / 30Hz (4:
The luminance signal Y of the 2: 2p) image signal is input to the low-pass filter 21. The low-pass filter 21 cuts out components of vertical 720 Lph or more from the input luminance signal. The output of the low-pass filter 21 is input to the low-pass filter 22, and components of horizontal 1080 Lpw or more are cut. The output of the low-pass filter 22 is output to the low-pass filter 23 and the low-pass filter 27.
And input to the adder 29.

In the low-pass filter 23, components of the output signal of the low-pass filter 22 that are equal to or more than 360 Lpw are cut off and output to the low-pass filter 24 and the adder 25. In the low-pass filter 24, components of the output signal of the low-pass filter 23 that are equal to or greater than 480 Lph are cut off and output to the adder 25. The output of the low-pass filter 23 (horizontal 36
0 Lpw or less and vertical 720 Lph or less luminance component)
And the output of the low-pass filter 24 (a luminance component of 360 Lpw or less in the horizontal direction and a luminance component of 480 Lph or less in the vertical direction) are subtracted (the output signal of the low-pass filter 23-the output signal of the low-pass filter 24), and the horizontal 0 to 360 Lpw and the vertical 480 to 720 Lph The luminance component, that is, VH in FIG.
Is output from the adder 25. Further, the output signal of the adder 25 is input to the vertical frequency conversion unit 26, and the input horizontal 0-360 Lpw and vertical 480-720 Lph signals are converted into horizontal 0-360 Lp
w, and frequency conversion to a vertical band of 240 to 480 Lph. This frequency conversion is performed by applying 240 Lp to the input signal.
h. The output of the vertical frequency converter 26 is converted by the down converter 37 from the signal of the 720p / 30 Hz system to 480p / 3
The signal is down-converted to a signal of the 0 Hz system.

On the other hand, in the low-pass filter 27, a component of horizontal 720 Lpw or more in the output signal of the low-pass filter 22 is cut and input to the low-pass filter 28 and the adder 29. In the low-pass filter 28, components of 480 Lph or more in the vertical direction are cut out of the output signal of the low-pass filter 27, and luminance components of horizontal 0 to 720 Lpw and vertical 0 to 480 Lph, that is, luminance components corresponding to Y in FIG. 1 are output. . The output of the low-pass filter 28 is supplied to the
The signal of the / 30 Hz system is down-converted to a signal of the 480p / 30 Hz system.

In the adder 29, the output of the low-pass filter 22 (horizontal 0 to 1080 Lpw or less and vertical 0
輝 度 720 Lph or less) and low-pass filter 2
7 (horizontal 0 to 720 Lpw or less and vertical 0 to 7
20Lph or less) (the output signal of the low-pass filter 22-the output signal of the low-pass filter 27), and 720-1080 Lpw in the horizontal direction and 0-72 in the vertical direction.
A luminance component of 0 Lph is output. And the adder 29
Is output by the low-pass filter 30 in the vertical direction of 240 Lp.
h component is cut, horizontal 720-1080 Lpw,
In addition, a luminance component of 0 to 240 Lph in the vertical direction, that is, a signal component corresponding to HH in FIG. 1 is output. Further, the output signal of the low-pass filter 30 is input to the horizontal frequency conversion unit 31, and the input horizontal 720-1080 Lpw and vertical 0-240 Lph luminance components are converted to horizontal 0-360 Lph.
Lpw and frequency conversion to a vertical band of 0 to 240 Lph. This frequency conversion applies 720L to the input signal.
This is performed by applying a carrier of pw. And
The output signal of the horizontal frequency converter 31 is output by the vertical frequency converter 32 from 0 to 360 Lpw horizontally and from 240 to 360 Lpw vertically.
The frequency is converted to a luminance component of 480 Lph. This frequency conversion is performed by applying a carrier of 240 Lph to the input signal. The output of the vertical frequency conversion unit 32 is supplied to the
The signal of the / 30 Hz system is down-converted to a signal of the 480p / 30 Hz system.

On the other hand, in the color difference signal Cb, components of 360 Lpw or more in the horizontal signal are cut by the low-pass filter 33, and components of 240 Lph or more in the signal are cut by the low-pass filter 34. In addition, the color difference signal Cb in the vertical band of 0 to 240 Lph is obtained. The output of the low-pass filter 34 is output from the down converter 40 to the output of the 720p / 30
Hz signal is down-converted to a 480p / 30 Hz signal.

In the color difference signal Cr, the low-pass filter 35 cuts out components of horizontal signals of 360 Lpw or more, and the low-pass filter 36 cuts out components of vertical signals of 240 Lph or more. Further, it becomes a color difference signal Cr in a band of 0 to 240 Lph in the vertical direction. The output of the low-pass filter 36 is output from the down converter 41 to 720p / 30
Hz signal is down-converted to a 480p / 30 Hz signal.

In the adder 42, the luminance component VH (horizontal 0 to 3) downconverted by the downconverter 37 is output.
(60 Lpw, vertical 240 to 480 Lph) and the output signal (color difference signal Cb) of the down converter 38 are added (multiplexed). In the adder 43, the down converter 3
9, the luminance component HH (horizontal 0)
~ 360Lpw, and vertical 240 ~ 480Lph),
The output signal (color difference signal Cr) of the down converter 41 is added (multiplexed).

The multiplexing circuit 44 multiplexes the luminance signal Y, the chrominance signal Cb in which the luminance component VH is multiplexed, and the chrominance signal Cr in which the luminance component HH is multiplexed into 480 p / 30 Hz ( A video signal equivalent to the 4: 2: 2p) system is output.

Subsequently, 480 p / 30 Hz (4: 2: 2
The video signal corresponding to the p) system is input to the scanning line conversion unit 45, and the input video signal is converted from one field into two interlaced fields as shown in FIG. : 2: 2i) The video signal is equivalent to the system.

In the above description, the case where an ideal low-pass filter is used has been described. However, since a steep low-pass filter cannot be realized in practice, it is necessary to handle the band to be passed with some margin. .

In this embodiment, the luminance component VH is multiplexed with the color difference signal Cb, and the luminance component HH is multiplexed with the color difference signal Cr. However, the luminance component VH is converted into the color difference signal Cr, and the luminance component HH is converted into the color difference signal Cb. Each may be multiplexed.

Next, a decoder for decoding the video signal multiplexed by the encoder will be described. FIG. 4 is a block diagram of the decoder.

In FIG. 4, reference numeral 50 denotes 480i / 60 Hz (4: 2: 2) by combining two interlaced fields into one progressive scanning field.
i) A video signal equivalent to the system is converted to 480p / 30Hz (4:
2: 2p) A scanning line conversion unit for converting into a video signal equivalent to the system, 51 is a low-pass filter that cuts off a component of 240 Lph or more in the color difference signal Cb, 52 is an adder that adds the low-pass filter 51 and the color difference signal Cb. , 53 are an up-converter that inserts scanning lines and horizontal pixels into the output (480 p / 30 Hz system signal) of the adder 52 to up-convert to a 720 p / 30 Hz system signal.
Reference numeral 4 denotes a vertical frequency converter for shifting the output of the up-converter 53 to the vertical high frequency side; 55, a low-pass filter that cuts components of 240 Lph or more in the color difference signal Cr; 56, a low-pass filter 55 and the color difference signal Cr; The adder 57 performs the output of the adder 56 (480p / 3
0Hz signal) by inserting scanning lines and horizontal pixels,
An up-converter for up-converting the signal into a 720p / 30 Hz signal, a vertical frequency converter 58 for shifting the output of the up-converter 57 to the vertical high frequency side, and a shift circuit 59 for shifting the output of the vertical frequency converter 58 to the horizontal high frequency side This is a horizontal frequency converter. And 60, 61 and 62
Is an up-converter that inserts scanning lines and horizontal pixels from a signal of the 480 p / 30 Hz system and up-converts the signal into a signal of the 720 p / 30 Hz system, 63 denotes an output of the vertical frequency converter 54, an output of the horizontal frequency converter 59, This is an adder for adding the output of the up-converter 62.

Next, the operation of the decoder in the above configuration will be described. First, 480i / 60Hz (4: 2: 2
i) A video signal corresponding to the method is input to the scanning line conversion unit 50. Then, the two signals are combined for every two fields of the interlaced system to form one field of the progressive scanning system, so that a video signal equivalent to the 480i / 60 Hz (4: 2: 2i) system can be converted to a 480p / 30 Hz (4: 2 : 2
It is converted to a video signal equivalent to the p) system.

Subsequently, the low-pass filters 51 and 55 are
From the video signal corresponding to the 480p / 30 Hz (4: 2: 2p) system, the vertical direction is calculated from the color difference signal Cb and the color difference signal Cr by 240.
Cut the components above Lph. The adders 52 and 56 subtract the output signals of the low-pass filters 51 and 55 from the input color difference signals Cb and Cr. The outputs of the adders 52 and 56 are output to the up-converter 5.
According to 3,57, the signal of 480p / 30Hz system is 7
The signal is up-converted into a signal of the 20p / 30 Hz system.

On the other hand, the outputs of the low-pass filters 51 and 55 are output by the up-converters 60 and 61 to 480 p / 3
The signal of the 0 Hz system is up-converted into a signal of the 720p / 30 Hz system, and is converted into a color difference signal Cb and a color difference signal Cr of the 720p / 30 Hz system.

The vertical frequency converter 54 outputs the output of the up converter 53 (horizontal 0 to 360 Lpw, vertical 240 to
480 Lph) is converted to a frequency of 0 to
The signal is converted into a band of 360 Lpw and a vertical band of 480 to 720 Lph, that is, converted into a signal component corresponding to VH in FIG.

In the vertical frequency converter 58, the output of the up-converter 57 (horizontal 0 to 360 Lpw, vertical 2
40 to 480 Lph) in the vertical direction and frequency conversion in the horizontal direction to 0 to 360 Lpw and vertical to 0 to 240 Lph. Further, this signal is converted by the horizontal frequency converter 59 into a horizontal 720 to 1080 Lpw and a vertical 0 to 240 Lp
The signal is converted into a band of h, that is, converted into a signal component corresponding to HH in FIG.

In the adder 63, the up converter 62 converts the signal of the 480p / 30Hz system into 720p / 3.
Luminance signal Y up-converted to 0 Hz signal
(Horizontal 0-720 Lpw, vertical 0-480 Lph),
The output of the vertical frequency conversion unit 54 (horizontal 0 to 360 Lpw,
Vertical 480-720 Lph) and horizontal frequency converter 59
Output (720-1080 Lpw horizontal, 0-240 vertical)
Lph) are added to obtain a luminance signal equivalent to 720p / 30 Hz.

In the above description, the case where an ideal low-pass filter is used has been described. However, since a steep low-pass filter cannot be realized in practice, the band to be passed must be dealt with with some margin. .

In the above-described embodiment, both the high frequency component in the horizontal direction and the high frequency component in the vertical direction are multiplexed on the color difference signal. However, depending on the situation, either the high frequency component in the horizontal direction or the high frequency component in the vertical direction is used. Only one of them may be multiplexed. In this case, the decoding side may be configured to extract only one of the multiplexed signal components.

Next, a second embodiment will be described. In the second embodiment, the signal system is 480i / 60Hz (4:
A 2: 2i) method is characterized in that a luminance signal is multiplexed into a color difference signal and a pilot signal (identification signal) indicating that the signal is a 720p / 30 Hz signal is inserted into the signal.

FIG. 5 is a block diagram of the second embodiment. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. 5, 100 and 10
Reference numeral 1 denotes a pilot signal generation circuit that generates a pilot signal indicating that a part of the luminance component is multiplexed with the color difference component. This pilot signal generation circuit 100
And 101, as shown in FIG. 6, are for sequentially generating contradictory signals, for example, + X and -X signals. Then, the pilot signals generated by the pilot signal generation circuits 100 and 101 are input to adders 37 and 38, and are multiplexed into the color signals Cb and Cr.

The multiplexed pilot signal is inverted in all directions of pixels, lines, and frames, and has the highest frequency in each direction. Therefore, the pilot signal is not conspicuous as an image, and is an optimal method for inserting the pilot signal.

On the other hand, on the decoding side, by detecting the pilot signal, it is possible to determine whether the input video signal is a multiplexed signal, and appropriate processing can be performed.

In the second embodiment, the pilot signal is multiplexed on the chrominance signal Cb and the chrominance signal Cr, but may be multiplexed on the luminance signal Y. In this case, as shown in FIG. 7, an adder 200 for adding a pilot signal is provided after the low-pass filter 28, and the pilot signal of the pilot signal generation circuit 100 is input to the adder, and The pilot signal is multiplexed. Even with this configuration, the same effect as in the above case can be obtained.

[0061]

According to the present invention, 720p / 30Hz
(4: 2: 2p) signals can be converted to 480i / 60 Hz (4: 2: 2i) signals while minimizing image quality degradation. As a result, 720p / 30Hz (4:
Even if the signal is of the 2: 2p) type, the use of the 480i / 60 Hz (4: 2: 2i) type infrastructure provided with the infrastructure provides an excellent effect that signal processing and transmission can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a multiplexing method according to the present embodiment.

FIG. 2 is a diagram for explaining a multiplexing method according to the present embodiment.

FIG. 3 is a block diagram of an encoder that implements a multiplexing method according to the present embodiment.

FIG. 4 is a block diagram of a decoder that implements a multiplexing method according to the present embodiment.

FIG. 5 is a block diagram according to a second embodiment.

FIG. 6 is a diagram for explaining a pilot signal according to the second embodiment.

FIG. 7 is a diagram for explaining another embodiment of the second embodiment.

[Explanation of symbols]

 21 to 24 Low-pass filter 25 Adder 26 Frequency converter 39 Multiplexer 40 Downconverter 45 Scan line converter

Continued on front page F term (reference) 5C057 BA11 BB00 BB02 CE01 EA02 EA06 EA07 EB02 ED02 ED04 ED06 GC01 GJ00 5C063 AB05 AB20 AC10 BA03 BA04 CA21 DA07 DA20 5C066 AA00 AA02 BA08 CA21 CA25 DD02 DD04 EE01 GA02 K05 GA02

Claims (19)

[Claims] 1. A method of converting a video signal, comprising: converting a luminance component of a 720p / 30 Hz system to 480p / 3
Luminance component required for 0 Hz system, 480p / 30
Extracting a horizontal high-frequency component and a vertical high-frequency component that are equal to or higher than the luminance component required for the Hz system, and 480p / 3 from the color difference component of the 720p / 30Hz system.
Extracting a color difference component required for the 0 Hz (4: 2: 0p) system; frequency-converting the extracted horizontal high-frequency component and vertical high-frequency component of the luminance, and multiplexing the extracted luminance component with the extracted color difference component; 480
generating a p / 30 Hz (4: 2: 2p) color difference component; 480 p / 3 comprising a luminance component required for the 480 p / 30 Hz method and a color difference component in which the luminance component is multiplexed.
A video signal corresponding to the 0 Hz (4: 2: 2p) system is converted from the progressive scanning system to the interlaced system, and is converted to 480i / 60.
And generating a video signal corresponding to the Hz (4: 2: 2i) system. 2. A video signal corresponding to a 480p / 30 Hz (4: 2: 2p) system is converted to a 480i / 60 Hz (4: 2: 2) video signal.
i) The step of converting into a video signal equivalent to the system is 480p /
2. The video signal conversion method according to claim 1, further comprising the step of dividing a scanning line of one field in the video signal corresponding to the 30 Hz (4: 2: 2p) format into two interlaced fields. 3. A method for converting a video signal, comprising: converting a video signal corresponding to a 480i / 60 Hz (4: 2: 2i) system from an interlaced system to a progressive scanning system;
A step of converting to a video signal equivalent to the 480p / 30Hz (4: 2: 2p) method, and from the 480p / 30Hz (4: 2: 2p) color difference component to a horizontal high-frequency component and a vertical high-frequency component of luminance. Extracting a component to be subjected to frequency conversion, and adding the horizontal high-frequency component and the vertical high-frequency component of the frequency-converted and returned luminance to the luminance component of the 480p / 30Hz system, thereby obtaining a luminance component equivalent to 720p / 30Hz. Generating a video signal. 4. A video signal corresponding to a 480i / 60 Hz (4: 2: 2i) system is converted to a 480p / 30 Hz (4: 2: 2) video signal.
p) The step of converting to a video signal equivalent to the method is 480i /
4. The video signal according to claim 3, wherein a step of combining two interlaced fields in the video signal corresponding to the 60 Hz (4: 2: 2i) format into one progressive scanning field. Conversion method. 5. The extracted horizontal high-frequency component and vertical high-frequency component of the extracted luminance are 480p / 30Hz (4: 2: 2p).
Signal bandwidth and 480p / 30Hz
5. The video signal conversion method according to claim 1, wherein the difference corresponds to a difference from a bandwidth of a color difference signal in the (4: 2: 0p) system. 6. The method according to claim 1, wherein identification information indicating that the luminance is multiplexed is embedded in one or both of the horizontal high-frequency component and the vertical high-frequency component of the luminance multiplexed into the color difference signal. The method for converting a video signal according to any one of claims 1 to 5. 7. The video signal conversion method according to claim 1, wherein identification information indicating multiplexing is embedded in the luminance signal. 8. A method for transmitting a video signal, comprising: converting a luminance component of a 720p / 30 Hz system to 480p / 3
Luminance component required for 0 Hz system, 480p / 30
Extracting a horizontal high-frequency component and a vertical high-frequency component that are equal to or higher than the luminance component required for the Hz system, and 480p / 3 from the color difference component of the 720p / 30Hz system.
Extracting a color difference component required for the 0 Hz (4: 2: 0p) system; frequency-converting the extracted horizontal high-frequency component and vertical high-frequency component of the luminance, and multiplexing the extracted luminance component with the extracted color difference component; 480
generating a p / 30 Hz (4: 2: 2p) color difference component; the extracted 480p / 30 Hz luminance component; and the generated 480p / 30 Hz (4: 2: 2p) color difference component. And 480p / 30Hz (4: 2: 2
p) generating a video signal equivalent to the 480p / 30 Hz (4: 2: 2p) method; converting the video signal equivalent to the 480p / 30 Hz (4: 2: 2p) method from a progressive scanning method to an interlaced method; 2i) generating and transmitting a video signal equivalent to the system. 9. 480i / 60Hz transmitted
A video signal equivalent to the (4: 2: 2i) system is converted from the interlace system to the progressive scanning system, and is converted to 480p / 30Hz.
(4: 2: 2p) conversion into a video signal equivalent to the system; and, from the 480p / 30 Hz (4: 2: 2p) system color difference component, a component corresponding to a horizontal high-frequency component and a vertical high-frequency component of luminance. And converting the frequency, and the transmitted 480p / 30Hz (4: 2: 2
The components corresponding to the horizontal high-frequency component and the vertical high-frequency component of the luminance are cut from the color difference components of the p) method, and 480p / 30H
returning to the z (4: 2: 0p) color difference component; adding the horizontal high-frequency component and the vertical high-frequency component of the frequency-converted and returned luminance to the luminance component of the 480p / 30Hz method to obtain 720p / The method according to claim 8, further comprising: generating a luminance component corresponding to 30 Hz. 10. The extracted horizontal high-frequency component and vertical high-frequency component of luminance are 480 p / 30 Hz (4: 2: 2
p) The bandwidth of the color difference signal in the system and 480p / 30H
The video signal transmission method according to claim 8 or 9, wherein the transmission method corresponds to a difference from a bandwidth of a color difference signal in a z (4: 2: 0p) system. 11. Embedding identification information indicating that the luminance is multiplexed in the horizontal high-frequency component and / or the vertical high-frequency component of the luminance multiplexed on the color difference signal, and transmitting the identification information on the receiving side. The video signal transmission method according to any one of claims 8 to 10, wherein the detection discriminates the multiplexed video signal and the non-multiplexed video signal on the receiving side. 12. An image which is not multiplexed with a video signal multiplexed on the receiving side by embedding identification information indicating that the video signal is multiplexed in the luminance signal and detecting the identification information on the receiving side. The method of transmitting a video signal according to claim 8, wherein the signal is distinguished. 13. An encoder for a video signal, wherein a luminance component of a 720p / 30 Hz system is 480p / 3
Luminance component required for 0 Hz system, 480p / 30
Extraction means for extracting a horizontal high-frequency component and a vertical high-frequency component that are higher than the luminance component required for the H.Z system, and 480 p / 3 from the color difference component of the 720p / 30 Hz system.
Second extraction means for extracting a color difference component required for a 0 Hz (4: 2: 0p) system; frequency conversion of the extracted high-frequency horizontal and vertical high-frequency components; 480
means for generating a color difference component of the p / 30 Hz (4: 2: 2p) system; 480 p / 30 comprising a luminance component required for the 480 p / 30 Hz system and a color difference component in which the luminance components are multiplexed.
Hz (4: 2: 2p) format video signal is converted from a progressive scanning format to an interlaced format and converted to 480i / 60H.
means for generating a video signal equivalent to the z (4: 2: 2i) system. 14. The method according to claim 14, wherein the first extracting means is 480p / 3
Horizontal high-frequency component and vertical high-frequency component of luminance corresponding to the difference between the bandwidth of the chrominance signal in the 0 Hz (4: 2: 2p) system and the bandwidth of the chrominance signal in the 480p / 30 Hz (4: 2: 0p) system 14. The video signal encoder according to claim 13, wherein the encoder is configured to extract the video signal. 15. A method comprising embedding identification information indicating that the luminance is multiplexed into one or both of the horizontal high-frequency component and the vertical high-frequency component of the luminance multiplexed on the color difference signal. The video signal encoder according to claim 13. 16. The video signal encoder according to claim 13, further comprising means for embedding identification information indicating multiplexing in a luminance signal. 17. A video signal decoder, which converts a video signal corresponding to a 480i / 60 Hz (4: 2: 2i) system from an interlace system to a progressive scanning system,
Means for converting to a video signal equivalent to the 480p / 30Hz (4: 2: 2p) method; and equivalent to the horizontal high-frequency component and the vertical high-frequency component of the luminance from the 480p / 30Hz (4: 2: 2p) color difference component. Extracting means for extracting a component to be converted, and frequency-converting the extracted component to 480 p / 30 Hz
(4: 2: 0p) conversion means for converting the luminance into a horizontal high-frequency component and a vertical high-frequency component of a luminance equal to or higher than the (4: 2: 0p) method, and a 480p / 30 Hz method using the horizontal high-frequency component and the vertical high-frequency component of the frequency-converted luminance. Add to the luminance component and get 7
Generating means for generating a luminance component corresponding to 20p / 30Hz. 18. A detection means for detecting identification information embedded in the color difference component, and when the identification information is detected by the detection means, the extraction means performs an extraction process to detect the identification information. 18. The video signal decoder according to claim 17, wherein the extraction unit is configured not to perform the extraction process when there is no video signal. 19. A detection means for detecting identification information embedded in the luminance component, and when the identification information is detected by the detection means, the extraction means performs an extraction process, and the identification information is detected. 18. The video signal decoder according to claim 17, wherein the extraction unit is configured not to perform the extraction process when there is no video signal.