JPH06217262A - Television circuit - Google Patents

Abstract

PURPOSE:To prevent large picture quality deterioration even if plural signal systems have a characteristic difference by converting a signal sequence in sequential scan mode into a signal sequence in two-sequence interlaced scanning mode, and performing time-base compression and multiplexing. CONSTITUTION:The signal VP from a sequential scanning camera 1 is converted into two-sequence interlaced scanning signals VIA and VIB by a sequential- interlaced scanning converting circuit 2. The signal VIA is multiplexed by a YC multiplexing circuit 4 with a luminance signal Y and a color signal C to generate a signal YC, thereby performing signal processing (VRT recording, switcher processing, etc.) in a station. The signals VIA and VIB are converted into a signal VAB of one sequence by the 1/2 time-base compression of a time- base compressing and multiplexing circuit 3 to perform signal processing in the station. At this time, a synchronizing signal for the positioning between the signals YC and VAB may be added. Then the signals YC and VAB are multiplexed by a letter box multiplexing circuit 5 to generate a transmitted signal VI.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television circuit, and more particularly to a television circuit suitable for use in various signal processing performed in a broadcasting station.

[0002]

2. Description of the Related Art The current television system (NTSC system.
In the following, abbreviated as the current method), one frame is divided into two fields and transmitted by interlaced scanning. In conventional television receivers (hereinafter abbreviated as current receivers), display is performed with interlaced scanning, so that the roughness of the reproduced image and flicker interference (flicker) due to the scanning line structure of every other line cause deterioration of the image quality. It was the cause.

In order to reduce this image quality deterioration, the first generation EDTV receiver (clear vision receiver) performs scanning line interpolation processing, and sequentially converts and displays the scanning pattern. However, there is a limit to image quality improvement in progressive scanning that is performed only by signal processing on the receiving side, and vertical resolution decreases in a moving part of the image, or aliasing distortion due to interlaced scanning cannot be completely removed. There was a problem.

In order to solve these problems, transmission of a vertical time enhancement signal (VT reinforcement signal) for progressive scanning is being studied in the second generation EDTV, which is currently under standardization. As shown in FIG. 2, in this system, a signal source of progressive scanning mode is used on the transmitting side, and a signal converted into an interlaced scanning mode (black circles in the figure) is transmitted as a main signal.
Scan line signals that are skipped and cannot be transmitted (white circles in the figure)
And the main signal is transmitted as a VT reinforcement signal. On the receiving side, the scanning line signal skipped from the main signal and the VT reinforcement signal is reproduced and sequentially scanned. As a typical method of creating a VT reinforcement signal, a method (LD method) that takes the difference between the scanning line signal (x in the drawing) that is skipped and the upper and lower scanning line signals (b and c in the drawing) And the scanning line signal (a in the figure) of the previous field.

The VT-enhanced signal created in this way is multiplexed on the non-picture part at the top and bottom of the letterbox format wide screen as shown in FIG. 3 and transmitted to the receiving side. The main picture part in the center of the screen has the same signal form as the current system, and the image of the main picture part can be viewed without changing the existing receiver. EDTV
In the receiver, by decoding the signal of the main image portion (main signal) and the signal of the non-image portion (VT reinforcement signal) together,
High quality images can be played.

On the other hand, in the signal processing in the broadcasting station, the above-mentioned letterbox format is not encoded, but the sequential scanning signal is converted into two systems of interlaced scanning signals as shown in FIG. On the other hand, it has been proposed to perform signal processing by current equipment. That is, in the figure, the signal VP from the sequential scanning camera 1 is sequentially
The interlaced scanning conversion circuit 2 converts the interlaced scanning signals (VIA, VIB) into two systems, and the signal sequence VIA used as the main signal is multiplexed by the YC multiplexing circuit 4 with the luminance signal Y and the color signal C. The signal sequence VIB for creating the VT augmented signal may or may not be YC multiplexed. In this way, immediately after transmission (broadcasting), the same signal form as the current signal is used as the in-station signal for both systems, and signal processing is performed using existing equipment (VTR, switcher, in-station / inter-station transmission device, etc.). Then, it is encoded by the letterbox multiplexing circuit 5 into the above-mentioned letterbox format, converted into the transmission signal VI and transmitted. The above process eliminates the need to newly purchase or change the specifications of expensive equipment for letterbox processing, which is very economical.

[0007]

As shown in FIG. 4, the sequential scanning signal VP is simply converted into two systems of interlaced scanning signals (VI).
When performing signal processing separately for A and VIB), a characteristic difference between the two systems (amplitude characteristic, phase characteristic, non-linear characteristic, etc.) becomes a problem. For example, when there is a difference in DC level between the two, the scanning line signals of black circles and white circles shown in FIG. 2 do not have the same level when returning to the sequential scanning signal again.
Flicker will occur. In particular, when analog signal processing is performed, it is very difficult to completely match these characteristics between the two systems, and image quality deterioration such as flicker cannot be avoided.

An object of the present invention is to provide a television circuit which enables a progressive scanning signal to be handled by a current device for interlaced scanning and which does not cause a large deterioration in image quality even if a characteristic difference occurs between a plurality of signal systems. To do.

[0009]

In order to achieve the above object, a means for converting a signal sequence (VP) of progressive scanning mode into two systems of interlaced scanning mode (VIA, VIB), and the above two systems The signal sequence (VIA, VIB) of (1) is time-axis compressed and multiplexed.

Alternatively, a signal sequence (V
A means for replacing the sync signal of P) with the sync signal of the current signal is used.

[0011]

After the signal sequence (VP) of the progressive scanning mode is converted into the interlaced scanning signals of two systems (VIA, VIB),
The signal VIA and the signal VIB are time-axis compression multiplexed to form one interlaced scanning signal sequence (VAB). This signal V
No matter what kind of signal processing is performed on AB, the influences of the signal VIA and the signal VIB are always the same, so that there is no characteristic difference and the above-mentioned problem of flicker does not occur.

By adding the same sync signal (horizontal and vertical composite sync signal) as in the current system to the time-axis compression-multiplexed signal VAB, the current system equipment (VTR, switcher, etc.) Signal processing becomes possible. Further, the signal VIA is separately processed as a main signal YC in the station.

Immediately before transmission (broadcasting), the signal VAB is subjected to inverse processing (time axis expansion separation processing) to obtain the signal VI.
A "and the signal VIB" are reproduced, and a VT reinforcement signal is created from both signals. On the other hand, by replacing the low frequency component of the main signal YC with the low frequency component of the reproduced signal VIA ″, a new main signal M
Let N. By transmitting (broadcasting) the main signal MN and the reinforcement signal VT, the characteristics between the main signal and the auxiliary signal can be made uniform with respect to the low frequency component. Further, even if a characteristic difference occurs between the signals of the two systems (YC and VAB) due to the signal processing in the station, different image bands are used, so that the image quality is not significantly deteriorated.

Separately from the above, even if the sync signal of the progressive scan signal VP is removed to reduce the interval between the odd scan lines and the even scan lines and a new composite sync signal similar to the current signal is added, A signal equivalent to the above-mentioned signal VAB can be obtained.

With the above operation, the object of the present invention can be achieved.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention.
In the figure, the signal VP from the sequential scanning camera 1 is converted into two systems of interlaced scanning signals VIA and VIB by the sequential-> interlaced scanning conversion circuit 2. With respect to the signal VIA, the YC multiplexing circuit 4 multiplexes the luminance signal Y and the color signal C into a signal YC, and performs in-station signal processing (VTR recording, switcher processing, etc.). On the other hand, signal VIA
And the signal VIB by the time axis compression multiplexing circuit 3 described later.
The signal is converted into a system signal VAB, and signal processing in the station is performed. At this time, a synchronization signal for aligning the positions of the signal YC and the signal VAB may be added. Signal YC and signal VAB
It is multiplexed by a letterbox multiplexing circuit 5 described later to form a transmission signal VI.

FIG. 5 shows an example of the configuration of the time axis compression / multiplexing circuit 3.
The operation is shown in FIG. In this circuit, the interlaced scanning signals VIA and VIB of the two systems are time-axis-compressed by ½ and then time-axis multiplexed to generate a signal VAB. In the figure, signals VIA and VIB are respectively time-axis compressed to 1/2 by a time-axis compression circuit 6 including a filter 7 for preventing aliasing distortion due to pixel thinning, a memory circuit 8 and a control circuit 9, and then the signal VIA is obtained. '
And VIB '. At this time, by making the read speed of the memory circuit 8 twice as fast as the write speed, the time axis compression process can be easily realized. Compressed signal VIA '
And the signal VIB 'are switched by the switch 10 for each scanning line (1/2 scanning line after time axis compression) and time-multiplexed, and the synchronization signal adding circuit 11 synchronizes the same synchronization signal (horizontal Vertical composite sync signal)
Is added to form the output signal VAB. When the signal VAB is observed on the current monitor, the input signal VIA is output on the left side of the screen and the input signal VIB is output on the right side of the screen.

FIG. 7 shows a configuration example of the letterbox multiplexing circuit 5. In this circuit, the signal YC in which the luminance signal and the chrominance signal are multiplexed and the signal VAB in which the time axis compression is multiplexed are multiplexed in the letterbox format shown in FIG. In the figure, after a signal VIA "and a signal VIB" are reproduced from a signal VAB by a time axis expansion / separation circuit 12 described later, a reinforcement signal VT is generated by a VT signal creation circuit 13 described later.
To create. In order to be able to multiplex this VT reinforcement signal in the letterbox non-picture part, the time axis compression circuit 14 makes it 1/3.
After the time axis compression, the rearrangement circuit 15 moves to the non-image area. On the other hand, by using the filters 16 and 17 and the adder 18, the low-frequency component of the signal YC (for example, 1.4 MHz or less = 4.2 MHz × 1/3 or less when the reinforcing signal VT is compressed and multiplexed 1/3) Reproduced signal VIA "
To be the main signal MN. The switcher 19 is used to switch and output the main signal MN and the reinforcement signal VT so that the letter box format is achieved.
I.

FIG. 8 shows a configuration example of the time axis expansion / separation circuit 12. In this circuit, the time-domain compression multiplexed signal VA
From B, the two systems of interlaced scanning signals VIA ″ and VIB ″ returned to the original time axis are reproduced. In the figure, the switch 20 switches the output destination between the left side and the right side of the screen to separate the compressed signal VIA ′ and the compressed signal VIB ′. The respective signals are sent to the memory circuit 22 and the control circuit 23.
And a signal VIA ″ which is returned to the original time axis by a time axis expansion circuit 21 including a filter 24 for removing aliasing distortion.
And VIB ″. At this time, by setting the read speed of the memory circuit 22 to half the write speed,
The time axis extension processing can be easily realized.

FIG. 9 shows a first configuration example of the VT signal generation circuit 13. In this circuit, the reinforcement signal VT is created by taking the difference signal (LD) from the upper and lower scanning line signals in the same frame in the progressive scanning mode from the two systems of interlaced scanning signals VIA "and VIB". In the figure, the 1H delay circuit 25, the adder 26 and the coefficient circuit 27 perform intra-field interpolation (inter-line interpolation) of the signal VIA ″.
A subtracter 28 is used to create a difference signal between the interpolation signal and the signal VIB ″, and the coefficient circuit 29 reduces the amplitude to ½ to create the reinforcement signal VT.

FIG. 10 shows a second configuration example of the VT signal generation circuit 13. In this circuit, a supplementary signal VT is created by taking a frame difference signal (FD) of a progressive scanning form from the interlaced scanning signals VIA ″ and VIB ″ of two systems.
In the same figure, the signal VI is output by the 263H delay circuit 30.
A "inter-field interpolation is performed. A subtracter 31 produces a difference signal from the signal VIB", and a coefficient circuit 32 reduces the amplitude to 1/2 to produce a reinforcement signal VT.

FIG. 11 shows the configuration of another embodiment of the present invention. In this configuration, the signal VAB is created by changing the synchronization signal of the sequential scanning signal VP instead of creating the signal VAB from the interlaced scanning signals of the two systems.
In the figure, the signal VP from the sequential scanning camera 1 is converted into the interlaced scanning signal VIA by the sequential-> interlaced scanning conversion circuit 33, and the luminance signal Y and the color signal C are multiplexed by the YC multiplexing circuit 4 to obtain the signal YC. . On the other hand, the synchronization changing circuit 34, which will be described later, changes the sequential scanning signal VP to the signal VA.
Convert to B. The signal YC and the signal VAB are similarly subjected to in-station signal processing, and then converted to the letterbox format by the above-mentioned letterbox multiplexing circuit 5 to transmit the transmission signal VI.
And

FIG. 12 shows the operation of the sync signal replacement circuit 34. As shown in the figure, the input progressive scanning signal V
P is already in a form in which the time axis is compressed to 1/2. However, since the horizontal synchronizing signal (or the horizontal blanking period) is inserted for each one scanning line (sequential scanning half scanning line) of the sequential scanning, this synchronizing signal is deleted and the odd scanning lines and the even scanning are performed. The line spacing is reduced and a new composite sync signal similar to the current signal is added. By this processing, a signal equivalent to the above-mentioned signal VAB can be obtained, and the existing equipment (VTR, switcher, etc.) can be used as it is.

FIG. 13 shows an example of the configuration of the intra-station signal processing circuit. This circuit is an example of a circuit that synthesizes the signal YC1 and the signal VAB1 created from the first signal source with the signal YC2 and the signal VAB2 created from the second signal source by processing such as chroma keying. In the figure,
The key signal extraction circuit 36 extracts the key signal k1 from the signal YC1 by detecting a blue background or the like. According to the signal k1, the combining circuit 37 combines the signal YC1 and the signal YC2 into a signal YC3. On the other hand, the key signal k1 is converted into a key signal k2 by the memory circuit 38 and the control circuit 39 into a form similar to that of the signal VAB as described later. According to the key signal k2, the synthesizing circuit 4
The signal VAB1 and the signal VAB2 are combined by 0, and the signal V
It is set to AB3. Key signal extraction circuit 36 and synthesis circuit 3
Current devices 7 and 40 can be used as they are, and can be realized by the conventional technique, and therefore are not illustrated.

FIG. 14 shows the operation of the above-mentioned intra-station signal processing circuit in more detail. First, the key signal k1 is extracted from the input signal YC1. The key axis k2 for the signal VAB1 is created by compressing the time axis of the key signal k1 to ½ and repeating it. According to the key signal k2, the signal VAB1 and the signal VAB2 are combined. The above-mentioned time base compression processing and repetition processing are performed by the memory 3
This is realized by the write / read control of 8. It should be noted that although description has been given here by taking an example of combination with a key signal, the present invention is not limited to this, and modification, enlargement / reduction, etc. can be realized by performing similar key signal processing.

Although the case where the line difference signal (LD) and the frame difference signal (FD) are used as the reinforcement signal VT has been described above as an example, in addition to this, SSKF (Symmetrical Short).
Kernel Filter) and QMF (Quadrature Mirror Filte)
It is clear that the present invention is likewise applicable to the case of the augmented signal VT created using a perfect reconstruction filter bank such as r).

[0028]

According to the present invention, the progressive scanning signal can be handled by the current device for interlaced scanning, and a large image quality deterioration does not occur even if a characteristic difference occurs between a plurality of signal systems. .

[Brief description of drawings]

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

FIG. 2 is an operation diagram of VT signal processing.

FIG. 3 is an operation diagram of letterbox multiplexing.

FIG. 4 is a configuration diagram of a conventional example.

FIG. 5 is a configuration diagram of a circuit used in the present invention.

FIG. 6 is an operation diagram of a circuit used in the present invention.

FIG. 7 is a configuration diagram of a circuit used in the present invention.

FIG. 8 is a configuration diagram of a circuit used in the present invention.

FIG. 9 is a configuration diagram of a circuit used in the present invention.

FIG. 10 is a configuration diagram of a circuit used in the present invention.

FIG. 11 is a configuration diagram of another embodiment of the present invention.

FIG. 12 is an operation diagram of a circuit used in the present invention.

FIG. 13 is a configuration diagram of a circuit used in the present invention.

FIG. 14 is an operation diagram of a circuit used in the present invention.

[Explanation of symbols]

1 ... Camera, 2,33 ... Sequential-> interlaced scanning conversion circuit, 3 ... Time axis compression multiplex circuit, 4 ... YC multiplex circuit, 5 ... Letterbox multiplex circuit, 6,14 ... Time axis compression circuit, 7,16,17 , 24 ... Filter, 8,22,38 ... Memory circuit, 9,23,39 ... Control circuit, 10,1
9, 20 ... Switcher, 11 ... Sync signal addition circuit, 12 ... Time axis expansion / separation circuit, 13 ... VT signal creation circuit, 15 ... Rearrangement circuit, 18, 26 ... Adder, 21 ... Time axis expansion circuit, 25, 30 ... Delay circuit, 27, 29, 32 ... Coefficient circuit, 28, 31 ... Subtractor, 34 ... Sync signal replacement circuit, 35 ... In-station signal processing circuit, 36 ... Key signal extraction circuit, 37, 40 ... Combining circuit.

Claims (5)

[Claims] 1. A signal sequence (VI) of the first form and a n-system (n is an integer of 2 or more) of the second form.
And a means for converting the n signal series VI into a 1 / n time-axis-compressed and multiplexing means. 2. A signal sequence (VI) of the first form and a n-system (n is an integer of 2 or more) of the second form.
And a means for removing the synchronizing signal of the signal series VP and adding a synchronizing signal of the signal series VI. 3. The television circuit according to claim 1 or 2, wherein the first mode is a progressive scanning mode. 4. The first mode, the second mode, and the third mode, wherein the second mode is an interlaced scanning mode.
The television circuit according to the item. 5. The television circuit according to any one of claims 1, 2, 3, and 4, wherein n = 2.