JPH07203388A - Multiple signal correcting circuit - Google Patents

Abstract

PURPOSE:To supply a correction signal to a luminance signal system or a chrominance signal system without deteriorating it. CONSTITUTION:An input signal inputted through an input terminal 41 is Y/C separated, a luminance signal is outputted from a MIX 47 and a chrominance signal is outputted from a MIX 48. The output of the MIX 47 is supplied to a selector 83. The input signal is also inputted to the selector 83 through a delay circuit 81. An EDTV judging circuit 82 judges whether the input signal is a 2nd generation EDTV signal or not and outputs a gate pulse for discriminating a main screen part period or an upper/lower no-image part period. The selector 83 is controlled by the gate pulse and selects the output of the MIX 47 in the main screen part period or selects the output of the circuit 81 in the upper/lower no-image part period. Consequently a compensation signal multiplexed to the upper/lower no-image part can be supplied to the luminance signal system without executing its Y/C separation processing.

Description

Detailed Description of the Invention

[Object of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiple signal correction circuit, and more particularly to a multiple signal correction circuit suitable for a compensation signal in a second generation EDTV.

[0002]

2. Description of the Related Art Conventionally, television broadcasting by a first generation EDTV (Extended Definition TV) has been performed in response to the demand for higher image quality. Furthermore, since 1995, the current N
A television broadcast by a second-generation EDTV that expands the aspect ratio to 16: 9 while maintaining compatibility with TSC television broadcast is also planned. Second generation EDT
The V monitor is designed to reduce flicker by non-interlaced scanning.

Since the second generation EDTV needs to be transmitted with the same standard as the television broadcast signal of the current NTSC system, the vertical direction of the second generation EDTV signal is compressed to 3/4 and the aspect ratio is 4 :. Only the central 16: 9 portion of the current NTSC signal of No. 3 is used as an effective scanning line. That is, the number of effective scanning lines of the current NTSC signal is 480, whereas the number of effective scanning lines of the second generation EDTV signal to be transmitted is 3.
It will be 60. At the time of decoding, the 360 effective scanning lines are converted from 3 to 4 scans and returned to 480 lines. Therefore, the second-generation EDTV signal has a lower vertical resolution than the current NTSC signal. Therefore, in the second-generation EDTV, it is considered to multiplex and transmit a compensation signal for improving the vertical resolution during transmission.

FIG. 9 is a circuit diagram showing a second-generation EDTV encoder for producing such a second-generation EDTV system television signal. The example of FIG. 9 employs a method of multiplex-transmitting a high frequency component in the time direction as a compensation signal. In the second generation EDTV, the compensation signal is adaptively created for a still image and a moving image.

Sequential scanning signals (the number of scanning lines is 525 (the number of effective scanning lines is 480) transmitted to the input terminals 1 and 2 of FIG.
Main), a luminance signal Y and a color signal C having a frame frequency of 60 Hz) are input. The video signal Y from the input terminal 1 is given to the frame memory 3, the adder 4 and the subtractor 5.
The frame memory 3 stores the video signal Y for one frame period (52
5H (horizontal period)) and delay the delay signal to the adder 4 and the subtracter 5. The adder 4 adds the video signals before and after one frame, and the addition result is halved by the coefficient unit 6. The subtractor 5 subtracts the video signals of about one frame and the subtraction result is multiplied by 1/2 by the coefficient unit 7. By the addition and subtraction processing of the video signals of about one frame, the input video signal having a band of 30 Hz in the time direction is separated in the time axis direction, and the coefficient unit 6 lowers the video signal Y in the time direction (temporal) of 0 to 15 Hz. A frequency component is output, and the coefficient unit 7 outputs the video signal Y in the time direction of 15 Hz to 30 Hz (temporal).
High frequency components are output.

The temporal low-frequency component and the temporal high-frequency component are double-expanded by the time-axis expansion circuits 8 and 9, respectively, and converted into a progressive scanning signal having a frame frequency of 30 Hz. The temporal low-frequency component from the time expansion circuit 8 is limited to 360 (TVL (television book) / PH (screen height)) by a vertical low-pass filter (hereinafter referred to as VLPF) 10, and then the 4 → 3 scan conversion circuit 11 Vertically by 3
Compressed to / 4. 4 due to bandwidth limitation of VLPF10
→ Prevents aliasing due to 3-scan conversion. In this way, it is converted to a letterbox format image. In the case of a complete still image, the output of the 4 → 3 scan conversion circuit 11 may be given to the interlace conversion circuit 22 via the mixing circuit (hereinafter referred to as MIX) 14 to be used as the signal of the main screen section.

The output of the 4 → 3 conversion circuit 11 is horizontal and vertical 2
It is also given to the dimensional low-pass filter (hereinafter referred to as HVLPF) 12. The HVLPF 12 is a 4 → 3 scan conversion circuit in order to facilitate separation from color signals on the decoding side.
The color signal band is removed from the output of 11 and output to the adder 13. In still images, luminance and color can be separated by calculation between frames, so the 4 → 3 scan conversion circuit 11
There is no two-dimensional band limitation on the output of.

In a complete still picture, the temporal high frequency component is 0, but in the case of not a complete still picture, the temporal high frequency component is also used to create an interlaced signal for the main screen portion. That is, the temporal high frequency component from the time expansion circuit 9 is input to the HVLPF 15, and the HVLPF 15 limits the band in the vertical direction so that the band is not folded back by the 4 → 3 scan conversion, and in the horizontal direction due to the limitation of the transmission band. Also band limit. The output of HVLPF 15 is a 4 → 3 conversion circuit 16
Are compressed to 3/4 in the vertical direction and converted into a letterbox format video signal. The output of the 4 → 3 scan conversion circuit 16 is given to the adder 13 via a vertical (V) shifter 17. By the time expansion of the time expansion circuits 8 and 9, the rate of the video signal becomes 1/2, and the video signal of the band 30 Hz is converted into the signal of the band 15 Hz, that is, the temporal low frequency component and the temporal high frequency band. The band of the component in the time direction overlaps. Therefore, the V shifter 17 shifts the vertical low band component of the temporal high band to the vertical high band side, and then the adder 13 adds it to the vertical low band component of the temporal low band.

The adder 13 obtains vertical low-frequency components of the entire band in the time direction by addition of two inputs and outputs them to the MIX 14. MI
X14 mixes the output of the 4 → 3 scan conversion circuit 11 which is a still image component and the output of the adder 13 which is a moving image component based on the motion vector detected by the motion detection circuit 31 and jumps as a signal of the main screen section. Output to the conversion circuit 22. The interlace conversion circuit 22 converts the input progressive scanning signal into an interlaced signal and outputs it to the selector 25 as a main screen signal.

On the other hand, the temporal low-pass component from the time expansion circuit 8 is also supplied to a vertical high-pass filter (hereinafter referred to as VHPF) 19 in order to create a compensation signal. VH
The PF19 is a vertical high frequency component (360
Through 480 [TVL / PH]) are separated. The vertical low frequency component of the temporal low frequency from the VHPF 19 is shifted to the vertical low frequency which can be transmitted by the V shifter 20, and then the 4 → 3 scan conversion circuit.
It is vertically compressed into 3/4 by 21 and output to MIX 18.

The MIX 18 includes a vertical high frequency component of the temporal low frequency from the 4 → 3 scan conversion circuit 21 and a 4 → 3 scan conversion circuit 16
And the vertical low-frequency components of the temporal high frequency range are selected adaptively based on the motion vector. That is, the MIX 18 selects the vertical high-frequency component of the temporal low frequency in the still image. That is, the video signals of 120 scanning lines in the vertical high range that are not transmitted by the main screen signal during a still image are transmitted as compensation signals. For moving images, select the vertical low-frequency component of the temporal high range. The output of MIX18 is 3 → 2
It is given to the conversion circuit 23. The output of MIX18 is 320 [TVL
/ PH] signal, so 24 by the 3 → 2 conversion circuit 23
After the signal is converted into a signal of 0 [TVL / PH], it is vertically compressed to 1/2 by the multiplex processing circuit 24. In addition, the multiplexing processing circuit 24 performs waveform shaping and rearrangement so that the signals can be multiplexed in the upper and lower non-image parts of the video signal, and outputs them to the selector 25 as a compensation signal. The selector 25 synthesizes the interlaced main screen signal from the interlace conversion circuit 22 and the compensation signal from the multiplex processing circuit 24 and outputs the synthesized signal to the NTSC encoder 30. Note that due to the limitation of the transmission band, the vertical high-frequency component of the temporal high frequency, which has a small contribution to the resolution, is not transmitted.

On the other hand, the color signal C input from the input terminal 2
Is given to the HVLPF 26 and band-limited based on the transmission band. The output of HVLPF 26 is a 4 → 3 scan conversion circuit.
It is given to 27 and compressed vertically to 3/4 and converted to letterbox format. The output of the 4 → 3 scan conversion circuit 27 is converted into an interlaced signal by the interlace conversion circuit 28 and given to the multiplier 29. The frequency of the multiplier 29 is 3.5
Color signals are quadrature-modulated using a color subcarrier of 8 MHz
Output to the TSC encoder 30. NTSC encoder 30
Indicates that the number of scanning lines is 525 (the number of effective scanning lines is 480) from the video signal from the selector 25 and the carrier color signal from the multiplier 29.
The interlaced composite video signal with a field frequency of 60 Hz is created by the
Output as a generation EDTV signal.

That is, in the circuit of FIG. 9, a vertical low-frequency component of the temporal low frequency of 360 [TVL / PH] is transmitted as a main screen signal during a still image, and 120 [TVL / PH] as a compensation signal.
The vertical low-frequency component of the temporal low frequency band will be transmitted, and a video with a resolution of 480 [TVL / PH] can be obtained by the decoding process. In addition, during a moving image, the vertical low-frequency component of the temporal low band of 360 [TVL / PH] and the vertical low-frequency component of the temporal high band are transmitted by the main screen signal and the compensation signal.

FIG. 10 is a circuit diagram showing a second generation EDTV decoder for decoding the second generation EDTV signal. In the decoder of FIG. 10, the field frequency is 60H.
z, the 2: 1 interlaced signal having 525 scanning lines is converted into a 1: 1 progressive scanning signal having a field frequency of 60 Hz and 525 scanning lines.

Second generation E input via input terminal 41
The DTV signal is a 525H delay circuit 42, an adder 43 and a subtractor
Given to 44. The 525H delay circuit 42 delays the input video signal by 525H and outputs it to the adder 43 and the subtractor 44. Since the phase of the carrier color signal is inverted for each frame and the luminance signals before and after one frame have a substantial correlation during a still image, the adder 43 adds the video signals before and after one frame. , The carrier color component is removed and a luminance signal is obtained. Further, the subtractor 44 separates the carrier color signal by subtracting the video signals before and after one frame. The coefficient units 45 and 46 multiply the separated luminance signal and carrier color signal by 1/2 and output them to the MIXs 47 and 48.

On the other hand, in the case of a moving image, it is necessary to separate the luminance signal and the carrier color signal by horizontal and vertical two-dimensional filters. The second-generation EDTV signal from the input terminal 41 is given to the two-dimensional LPF 49, and the luminance signal is separated to obtain MIX47.
Is supplied to. The two-dimensional BPF50 is the second generation EDT.
The carrier color signal band of the V signal is passed to give the carrier color signal to the MIX 48. The motion detection circuit 51 receives the input second generation E
The motion vector of the DTV signal is detected to control the MIXs 47 and 48. MIX 47 calculates a coefficient unit 45 based on the motion detection signal.
From the two-dimensional LPF 49 and the luminance signal at the time of a moving image are mixed and output to the frame synthesizing circuit 52. Further, the MIX 48 mixes the carrier color signal from the coefficient unit 46 in the still image and the carrier color signal from the two-dimensional BPF 50 in the moving image by using the motion detection signal and outputs the mixed signal to the broadband color demodulation circuit 53.

The frame synthesizing circuit 52 converts a signal having a field frequency of 60 Hz into a progressive scanning signal having a frame frequency of 30 Hz and outputs the signal to the MIX 53 and the subtractor 54. At the time of a still image, the frame synthesizing circuit 52 outputs only the temporal low frequency component and outputs it via the MIX 53. At the time of moving image, the output of the frame synthesizing circuit 52 includes the temporal low-frequency component and the vertical low-frequency component of the temporal high frequency as described above. Since the temporal low-frequency component and temporal high-frequency component overlap in the time direction due to frame synthesis, the decoding process separates the temporal low-frequency component and temporal high-frequency component from the main screen signal. And the compensation signal are calculated.

In order to separate the temporal low frequency component and the temporal high frequency component, the output of the frame synthesizing circuit 52 is given to the subtractor 54. On the other hand, the compensation signals of the upper and lower non-picture portions of the video signal are demodulated by the multiplex reproduction circuit 55 and converted into a progressive scanning signal having a frame frequency of 30 Hz. Compensation signal is 240 [TVL / P by the encoder 3 → 2 conversion circuit 23.
Since it is a signal of H], it is returned to the original signal of 360 [TVL / PH] by the 2 → 3 scan conversion circuit 56 and given to the V shifter 57. The V shifter 57 vertically shifts the vertical low-frequency component of the temporal high frequency included in the compensation signal, and supplies it to the subtractor 54. Thus, the subtractor 54 removes the vertical low frequency component of the temporal high frequency range from the output of the frame synthesizing circuit 52 to remove the MIX 53.
Output to.

The MIX 53 mixes the two inputs based on the motion detection signal and outputs it to the 3 → 4 scan conversion circuit 58. The 3 → 4 scan conversion circuit 58 outputs the output of MIX 53 (360 [TVL / PH]) to 4
It is converted into 80 [TVL / PH] signal and output. The temporal low frequency component from the 3 → 4 scan conversion circuit 58 is input to the adder 65 and the subtractor 66 via the adder 64.

On the other hand, the compensation signal from the multiple reproduction circuit 55 is also given to the coefficient units 59 and 60. The coefficient units 59 and 60 are for still images and moving images, respectively, and add the coefficients based on the motion detection signals to the compensation signals and output them to the 2 → 4 scan conversion circuits 61 and 62. The compensation signal at the time of a still image is a vertical high frequency component of the temporal low range, and the compensation signal at the time of a moving image is a vertical low frequency component of the temporal high range. The vertical high-frequency components of the temporal low frequency during the still image input to the 2 → 4 scanning line conversion circuit 61 are 360 to 480.
It is converted into a [TVL / PH] signal and given to the V shifter 63.
The V shifter 63 shifts the input signal to the vertical high band and supplies it to the adder 64. As a result, the adder 64
Thus, the vertical low band component and the high band component of the temporal low band are added to obtain a signal of 480 [TVL / PH].

The vertical low band component of the temporal high band at the time of the moving image input to the 2 → 4 scanning line conversion circuit 61 is converted into a signal of 480 [TVL / PH] and given to the adder 65 and the subtracter 66.
The adder 65 adds the temporal low-frequency component from the 3 → 4 scan conversion circuit 58 and the temporal high-frequency component from the 2 → 4 scan conversion circuit 62 and supplies the result to the sequential conversion circuit 67. The subtractor 66 outputs the 3 → 4.
The temporal low-frequency component output from the scan conversion circuit 58 is subtracted from the temporal high-frequency component output from the 2 → 4 scan conversion circuit 62 and applied to the sequential conversion circuit 68. Sequential conversion circuits 67 and 68 time-compress the input signal having a frame frequency of 30 Hz to 1/2 and convert the signals into a progressive scanning signal having a frame frequency of 60 Hz and output the signals. The output of the sequential conversion circuit 67 is given to the selector 70, and the output of the sequential conversion circuit 48 is 1 /
It is delayed by 60 seconds and provided to the selector 70. The selector 70 switches between two inputs and outputs every 1/60 seconds.

That is, the sum component of the temporal low band and the temporal high band and the difference component of the temporal low band and the temporal high band are alternately output from the selector 70 at a cycle of 1/60 seconds. That is, the temporal high frequency component is shifted by 15 Hz toward the high frequency side of the time axis, and the video signal Y composed of the temporal low frequency component of 0 to 15 Hz and the temporal high frequency component of 15 to 30 Hz is reproduced. To be done.

On the other hand, the carrier color signal from the MIX 48 is subjected to color demodulation by the wide band color demodulation circuit 53, and the 3 → 4 scanning conversion circuit.
71 with a frame frequency of 30 Hz and 480 scanning lines
Converted to a book signal. Further, the sequential conversion circuit 72 converts the frame frequency into a sequential scanning signal having a frequency of 60 Hz and outputs the signal.

As described above, in the second-generation EDTV broadcast, the compensation signal corresponding to the motion is multiplexed. In the decoder of FIG. 10, the compensation signal multiplexed in the upper and lower non-image parts of the video signal is input from the input terminal 41 to the multiplex reproduction circuit 55.
Is given to and demodulated. By the way, when watching the second generation EDTV signal with the receiver for the current NTSC broadcasting,
This compensation signal visually disturbs the upper and lower non-image parts. Therefore, in order to reduce visual interference caused by the compensation signal, it has been considered that the compensation signal is orthogonally modulated and multiplexed. In this case, the demodulation circuit for the compensation signal can be shared with the color demodulation circuit. In this way, considering the advantage of sharing hardware, reduce the system,
It is advantageous to pass the compensation signal through the hardware for the main screen of the luminance signal system or the chrominance signal system and then separate it.

However, the Y / C separation processing performed on the decoder side is performed not only on the main screen portion but also on the upper and lower non-image portions. The entire transmission band is normally used for the transmission of the compensation signal. Therefore, the spectrum of the compensation signal is modified by the two-dimensional BPF or the non-linear comb filter that separates the carrier color signal. Therefore, in this case, there is a problem that the compensation signal deteriorates.

Further, it has been considered to reduce the energy of the compensation signal in order to reduce the visual interference with the upper and lower non-image parts due to the compensation signal. However, in this case, it is necessary to increase the energy level of the decoder in order to reproduce the compensation signal.
There is also a problem that the S / N of the reproduced compensation signal deteriorates and the image quality deteriorates.

[0027]

As described above, in order to commonly use the hardware on the decoder side for the main screen signal and the compensation signal, the compensation signal is passed through the circuit for the main screen signal. The compensation signal is deteriorated by the Y / C separation processing for the main screen signal. Further, in order to reduce visual interference, the compensation signal is transmitted with energy suppressed, and since the energy of the compensation signal is increased on the decoder side during transmission, the S / N of the reproduced compensation signal is reduced. There is a problem that the image quality deteriorates and the image quality deteriorates.

The present invention has been made in view of the above problems, and a multiple signal correction circuit capable of preventing deterioration of a compensation signal and improving image quality without increasing visual interference due to the compensation signal. The purpose is to provide.

[Constitution of Invention]

In the multiple signal correction circuit according to the first aspect of the present invention, a compensation signal for compensating the main screen signal corresponding to the main screen portion at the center of the screen is supplied to the non-image areas above and below the screen. A period corresponding to the main screen portion and a period corresponding to the non-picture portion are determined while determining which of the wide television signal and the current television signal multiplexed in the corresponding period is input through the input terminal. And a luminance signal / color signal separating means for separating a television signal input through the input terminal into a luminance signal and a color signal, and a method determining means for outputting a gate signal for distinguishing between A through signal for outputting the reproduced television signal without passing through the luminance signal / color signal separating means, and a gate signal indicating that it is a period corresponding to the main screen portion from the system determining means are input. Then, the luminance signal and the color signal from the luminance signal / color signal separating means are output to the luminance signal system and the color signal system, respectively, and the gate signal indicating that it is a period corresponding to the non-image portion is input. And a selecting means for outputting the output of the through path to the luminance signal system or the color signal system in place of the luminance signal or the color signal from the luminance signal / color signal separating means. The wide-angle television signal in which the compensation signal for compensating for the main screen signal corresponding to the main screen portion at the center of the screen is multiplexed in the period corresponding to the non-picture areas at the top and bottom of the screen. And a current television signal are input through an input terminal, and a method of outputting a gate signal for distinguishing between a period corresponding to the main screen portion and a period corresponding to the non-image portion is determined. And a luminance signal / color signal for separating a luminance signal and a color signal by addition and subtraction of a delay signal obtained by delaying a television signal input through the input terminal for one frame period and the input television signal. Separation means, a through path for outputting the television signal input to the input terminal without passing through the luminance signal / color signal separation means, and a non-picture part motion judgment means for judging the motion of the non-picture part, When a gate signal indicating that it is a period corresponding to the main screen portion is input from the system determination unit, the luminance signal and the color signal from the luminance signal / color signal separation unit are input to the luminance signal system and the color signal system, respectively. When a gate signal indicating that it is a period corresponding to the non-image portion is input and is output, if the non-image portion movement determination means determines that the non-image portion is a moving image, The output of the through path is output to the luminance signal system or the color signal system in place of the luminance signal or the color signal from the luminance signal / color signal separating means, and the non-image portion is judged by the non-image part motion judging means. When it is determined that the part is a still image, a selection means for outputting the addition result of the luminance signal / color signal separation means to the luminance signal system is provided.

[0030]

According to the first aspect of the present invention, the luminance signal / chrominance signal separating means separates the television signal input through the input terminal into the luminance signal and the chrominance signal. Further, the input television signal is output via the through path without being subjected to the luminance signal / color signal separation processing. The method determining means outputs a gate signal that distinguishes a period corresponding to the main screen portion at the center of the screen and a period corresponding to the non-picture portion in which the compensation signals are multiplexed. During the period corresponding to the main screen portion, the luminance signal and the color signal from the luminance signal / color signal separating means are directly output by the selecting means. The selecting means outputs the output of the through path to the luminance signal system or the color signal system in place of the luminance signal or the color signal during the period corresponding to the non-image portion. As a result, the compensation signal multiplexed in the non-picture portion is multiplexed in the luminance signal system or the color signal system without being subjected to the luminance signal / color signal separation processing.

In the second aspect of the present invention, the luminance signal
The chrominance signal separating means separates the luminance signal and the chrominance signal by adding and subtracting the delay signal obtained by delaying the input television signal for one frame period and the input television signal. The selecting means outputs the through path when the method determining means indicates that the period corresponds to the main screen portion and when the non-image portion motion determining means determines that the non-image portion is a moving image. Is output to the luminance signal system or the color signal system instead of the luminance signal or the color signal. When the non-image part movement determination means determines that the non-image part is a still image, the selection means:
The addition result of the luminance signal / color signal separating means is output to the luminance signal system. As a result, a compensation signal with an improved S / N of -3db is output to the luminance signal system.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a multiple signal correction circuit according to the present invention. In FIG. 1, the same components as those in FIG. 10 are designated by the same reference numerals. In this embodiment, the compensation signal is superimposed on the luminance signal system.

The input terminal 41 has a second signal in which a compensation signal is multiplexed.
A generation EDTV signal is input. This second generation EDTV
The signal is given to the 525H delay circuit 42, the adder 43 and the subtractor 44. The 525H delay circuit 42 delays the input video signal by 525H and outputs it to the adder 43 and the subtractor 44. The adder 43 adds the input signal from the input terminal 41 and its 1-frame delay signal and outputs the addition result to the coefficient unit 45. The subtractor 44 subtracts the input signal from the input terminal 41 and the one-frame delay signal and outputs the subtraction result to the coefficient unit 46.

Since the phase of the input carrier color signal is inverted for each frame and the luminance signals before and after one frame have a substantial correlation during a still image, the output of the adder 43 is the luminance during a still image. It becomes a signal component, and the output of the subtractor 44 becomes a carrier color signal component at the time of still image. The coefficient units 45 and 46 multiply the input luminance signal and carrier color signal by 1/2 and output them to the MIXs 47 and 48, respectively.

The second generation EDTV signal from the input terminal 41 is also given to the two-dimensional LPF 49 and the two-dimensional BPF 50. Two
Dimension LPF 49 passes the horizontal and vertical luminance signal bands. The two-dimensional BPF 50 passes the horizontal and vertical carrier chrominance signal bands. The output of the two-dimensional LPF 49 is given to the MIX 47 as a luminance signal for a moving image, and the output of the two-dimensional BPF 50 is given to the MIX 48 as a carrier color signal for a moving image.

The second generation EDTV signal from the input terminal 41 is also given to the motion detection circuit 51. The motion detection circuit 51 detects the motion of the input video signal and outputs the motion detection signal as M
It outputs to IX47,48. MIX47 is
The luminance signal in the still image from the coefficient unit 45 and the luminance signal in the moving image from the two-dimensional LPF 49 are adaptively mixed at a ratio based on the motion detection signal and output to the selector 83. The MIX 48 adaptively mixes the still color carrier color signal from the coefficient unit 46 and the moving picture carrier color signal from the two-dimensional BPF 50 at a ratio based on the motion detection signal to obtain a wide band color of a color signal system not shown. It is designed to output to the demodulation circuit.

In this embodiment, the second generation EDTV signal from the input terminal 41 is also supplied to the selector 83 via the delay circuit 81. The delay circuit 81 receives the MIX signal from the input terminal 41.
The input signal is delayed by the amount of signal delay in the circuits up to 47 and output to the selector 83. The second generation EDTV signal from the input terminal 41 is also supplied to the EDTV determination circuit 82. The EDTV determination circuit 82 determines whether or not the input video signal is the second generation EDTV signal, and when it determines that the input video signal is the second generation EDTV signal, outputs a gate pulse indicating the upper and lower non-image portions to the selector 83. . The selector 83 is controlled by the gate pulse to select the output of the MIX 47 when the input video signal is not the second generation EDTV signal, and the input video signal is the second generation EDT.
In the case of the V signal, the output of the delay circuit 81 is selected in the upper and lower non-image part periods indicated by the gate pulse, and the output of the MIX 47 is selected in the other period (main screen part period). . The output of the selector 83 is provided to a luminance signal system frame synthesis circuit (not shown).

Next, the operation of the embodiment thus constructed will be described with reference to the explanatory view of FIG. Figure 2 is ED
The gate pulse from the TV determination circuit 82 will be described.

Second generation E input via input terminal 41
The DTV signal is delayed by the 525H delay circuit 42 for one frame period. The adder 43 adds the input signal from the input terminal 41 and its 1-frame delay signal to remove the carrier color signal and separate the luminance signal during a still image. The separated luminance signal is halved by the coefficient unit 45 and then applied to the MIX 47. The subtractor 44 subtracts the input signal from the input terminal 41 and the one-frame delay signal to remove the luminance signal and separate the carrier color signal during a still image. This carrier color signal is multiplied by 1/2 by the coefficient unit 46 and then supplied to the MIX 48.

On the other hand, the second generation EDTV from the input terminal 1
The signal is also input to the two-dimensional LPF 49 and the two-dimensional BPF 50. The two-dimensional LPF 49 separates the luminance signal and outputs it to the MIX 47 as a luminance signal for a moving image. Two-dimensional BPF50
Separates the carrier color signal and uses MI as the carrier color signal for moving images.
Output to X48. The MIX 47 mixes the output of the coefficient unit 45 and the output of the two-dimensional LPF 49 at a ratio based on the motion detection signal to obtain a luminance signal at the time of still image. Also, MIX
The 48 mixes the output of the coefficient unit 46 and the output of the two-dimensional BPF 50 at a ratio based on the motion detection signal to obtain a carrier color signal for a moving image. The carrier color signal from the MIX 48 is supplied to a wide band color demodulation circuit (not shown) of a color signal system. on the other hand,
The luminance signal from the MIX 47 is supplied to a frame synthesizing circuit of a luminance signal system (not shown) via the selector 83.

In the present embodiment, the compensation signals multiplexed in the upper and lower non-image parts are superimposed on the luminance signal system. That is, the second
The generation EDTV signal is time-matched with the output of the MIX 47 by the delay circuit 81 and given to the selector 83. The selector 83 is controlled by the gate pulse from the EDTV determination circuit 82, and selectively outputs the output of the delay circuit 81 or the output of the MIX 47.

The EDTV determination circuit 82 determines whether the video signal input to the input terminal 41 is a second generation EDTV signal. When the input video signal is not the second generation EDTV signal, the output of the MIX 47 is always selected by the gate pulse of the EDTV determination circuit 82. In this case,
The whole screen is the video part, there is no non-image part, MIX
An image can be displayed by using the output of 47.

On the other hand, when the input video signal is the second generation EDTV signal, the EDTV determination circuit 82 outputs a gate pulse for distinguishing the upper and lower non-picture area period from the main screen area period. The selector 83 is controlled by the gate pulse,
The output of the MIX 47 is selected in the main screen section period, and the output of the delay circuit 81 is selected in the upper non-picture section period and the lower non-picture section period.
In the second-generation EDTV, only the main screen portion is the video portion, and the video can be reproduced by selecting the luminance signal from the MIX 47 during the main screen portion. On the other hand, the compensation signal is multiplexed in the upper and lower non-image portion periods, and by selecting the output of the delay circuit 81 in this period, the compensation signal can be supplied to the luminance signal system. The compensation signal is merely delayed by the delay circuit 81 and is not deteriorated by the Y / C separation processing.

As described above, in this embodiment, the EDT
The V decision circuit 82 generates a gate pulse for distinguishing the non-picture part period of the second generation EDTV signal from the main screen period, and the selector
83 selects the luminance signal Y / C separated in the main screen period,
The output of the delay circuit 81 is selected during the upper and lower non-image part periods, and the compensation signal can be supplied to the luminance signal system without Y / C separation processing. For this reason, the hardware of the compensation signal system and the luminance signal system can be shared, the hardware scale can be reduced, and the deterioration of the compensation signal can be prevented to improve the image quality.

FIG. 3 is a block diagram showing another embodiment of the present invention. In FIG. 3, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the compensation signal is superimposed on the color signal system.

In this embodiment, the selector 83 is deleted and the MIX48
1 is different from the embodiment of FIG. 1 in that a selector 84 for switching and selecting the carrier color signal from the output and the output of the delay circuit 81 is provided. The selector 84 is controlled by the gate pulse from the EDTV determination circuit 82, and selects the output of the MIX 48 during the main screen period and the output of the delay circuit 81 during the upper and lower non-image area periods.

In the embodiment constructed in this way,
During the main screen period of the second generation EDTV, the carrier color signal from the MIX 48 is output from the selector 84. Further, during the upper and lower non-image part periods, the output of the delay circuit 81, that is, the compensation signal is output from the selector 84.

As a result, in this embodiment, the compensation signal can be supplied to the color signal system without Y / C separation processing. Other actions and effects are similar to those of the embodiment shown in FIG.

FIG. 4 is a block diagram showing another embodiment of the present invention. 4, the same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the compensation signal S
/ N is improved.

In this embodiment, a selector 87 is used instead of the selector 83.
1 is used to provide the output of the EDTV determination circuit 82 to the upper / lower non-image section motion determination circuit 86 and to supply the output of the upper / lower non-image section motion determination circuit 86 to the selector 83. The motion detection signal from the motion detection circuit 51 is also applied to the upper and lower non-image part motion determination circuit 86. Vertical non-image part motion determination circuit 86
When a gate pulse indicating the main screen period of the second generation EDTV signal is input from the EDTV determination circuit 82, the selector 87
A select signal for selecting the output of MIX47 is output to. When the gate pulse indicating the upper and lower non-picture portion period of the second generation EDTV signal is input from the EDTV judgment circuit 82, the upper and lower non-picture portion motion determination circuit 86 determines whether the motion detection signal is a still image or a moving image. Judgment, output a select signal for selecting the output of the delay circuit 81 at the time of moving image,
At the time of still image, a select signal for selecting the output of MIX47 is output.

Next, the operation of the embodiment thus constructed will be described with reference to the explanatory view of FIG. FIG. 5 shows the relationship between the motion determination result and the select signal, where M indicates a moving image and S indicates a still image.

Now, it is assumed that the EDTV determination circuit 82 determines that the signal of the main screen period of the second generation EDTV signal is input to the input terminal 41. When the gate pulse indicating the main screen period is input, the upper / lower non-image section motion determination circuit 86 outputs a select signal for causing the selector 87 to select the output of the MIX 47, as shown in FIG. As a result, the selector 87 selects and outputs the Y / C separated luminance signal.

Here, it is assumed that the EDTV determination circuit 82 determines that the signals of the upper and lower non-image portions have been input. When the gate pulse indicating the upper and lower non-picture portion period is input, the upper and lower non-picture portion motion determination circuit 86 creates a select signal based on the motion detection signal from the motion detection circuit 51. Since the second-generation EDTV signal input through the input terminal 41 is a moving image (M) and the upper and lower non-picture section motion determination circuit 86 selects the output of the delay circuit 81 as shown in FIG. The select signal of is output. In this case, the selector 87 performs the same selection as in the embodiment of FIG. 1 and supplies the compensation signal to the luminance signal system without undergoing the Y / C separation processing.

Next, it is assumed that the signals of the upper and lower non-image portions are still images (S). In this case, the upper / lower non-image section motion determination circuit 86
As shown in FIG. 5, the MIX47
A select signal for selecting the output of the coefficient unit 45 output via As described above, the compensation signal becomes a vertical high band component of the temporal low band during a still image. Since it is a still image, the compensation signal is the same signal for each frame.
On the other hand, the noise component has no correlation between frames. Therefore, in this case, the output of the coefficient unit 45 becomes a compensation signal in which the noise component is reduced by -3 dB. Selector 87
S / N is -3 by selecting the output of MIX47
The dB improved compensation signal can be supplied to the luminance signal system.

As described above, in this embodiment, Y / C
It is possible to prevent the compensation signal from deteriorating due to the separation processing, improve the S / N of the compensation signal by -3 dB, and output it to the luminance signal system.

FIG. 6 is a block diagram showing another embodiment of the present invention. 6, the same components as those of FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment employs a vertical non-image part motion determination circuit 88 in place of the vertical non-image part motion determination circuit 86 of the embodiment of FIG. The upper and lower non-image area motion determination circuit 88 is an input terminal
The input signal from 41 is given and the movement is detected. Similar to the embodiment of FIG. 4, the upper / lower non-image section motion determination circuit 88 outputs a select signal for selecting the output of MIX47 when it is determined that the image is a still image even in the upper / lower non-image section period. It is designed to output.

Also in the embodiment configured as described above,
Similar to the embodiment of FIG. 4, the S / N of the compensation signal is improved by −3 dB when the image is still. In this embodiment,
Without using the motion detection signal from the motion detection circuit 51,
The motion of the input signal is detected by the motion determining circuit 88 for the upper and lower non-image areas. As described above, the level of the compensation signal is relatively lower than the signal level of the main screen section. Therefore, if the motion determination of the upper and lower non-image portions is performed by the same motion detection processing as that of the main screen portion, there is a risk of erroneous detection. For this reason, in the present embodiment, the motion detection different from that for the main screen portion is performed, and there is an advantage that a reliable S / N improvement of the compensation signal can be obtained.

FIG. 7 is a block diagram showing another embodiment of the present invention. 7, the same components as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, a selector 91 is used in place of the selector 87 of FIG. 4, and an array conversion circuit 89 and a selector 90 are used in place of the upper / lower non-image movement determination circuit 86. Different from When the select signal is not input, the selector 91 determines that it is the main screen section period, and MI
It is designed to select the output of X47. Array conversion circuit
89 rearranges the motion detection signals from the motion detection circuit 51 and outputs them to the selector 90. The selector 90 is turned on when a gate pulse indicating that it is in the upper and lower non-image area period is input from the EDTV determination circuit 82, and outputs the output of the array conversion circuit 89 to the selector 91 as a select signal. .

The compensation signal is created by rearranging the vertical high-frequency component and the temporal high-frequency component of the main screen portion in the upper and lower non-image portions. Therefore, by rearranging the motion detection signals for the main screen section according to this rearrangement, this motion detection signal can be used as the motion detection signal of the compensation signal. The array conversion circuit 89 obtains the motion detection signal for the compensation signal by rearranging the motion detection signals from the motion detection circuit 51, and outputs it to the selector 90 as a select signal. The selector 91 selects the output of the delay circuit 81 by a select signal indicating that it is a moving image, and selects the output of the MIX 47 by a select signal indicating that it is a still image.

Next, the operation of the embodiment thus constructed will be described with reference to the explanatory view of FIG. FIG. 8 shows the operation of the array conversion circuit 89.

The motion detection signal of the main screen portion from the motion detection circuit 51 is converted by the array conversion circuit 89 as shown in FIG.
They are rearranged so as to correspond to the compensation signals of the upper and lower non-image areas. In the main screen section period, the selector 91 selects the output of the MUX 47, and the luminance signal separated by Y / C is output. In the upper and lower non-image part period, the EDTV determination circuit 82
The selector 90 is turned on by the gate pulse from, and the selector 91 is controlled by the select signal from the array conversion circuit 89.

When the select signal from the array conversion circuit 89 indicates a moving image, the selector 91 selects the output of the delay circuit 81. As a result, the compensation signal that has not been subjected to the Y / C separation processing can be given to the luminance signal system. When the select signal from the array conversion circuit 89 indicates a still image, the selector 91 selects the output of MIX47.
The output of MIX47 is a compensation signal with S / N improved by -3 dB.

In this way, also in this embodiment, the same effect as that of the embodiment of FIG. 4 can be obtained. Further, in the embodiment of FIG. 4, the selector 87 is controlled based on the motion detection signal for the main screen portion, but in this embodiment, the motion detection signal for the main screen portion is rearranged so as to correspond to the compensation signal. It controls the selector 91. This makes it possible to match the processing on the main screen signal with the processing on the compensation signals of the upper and lower non-image areas. Further, since the result of motion detection of the compensation signal, which is difficult to judge the motion, is not used, there is an advantage that the error of the motion judgment result is small.

[0066]

As described above, according to the present invention, it is possible to prevent deterioration of the compensation signal and improve the image quality without increasing the visual interference due to the compensation signal.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a multiple signal correction circuit according to the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the embodiment.

FIG. 3 is a block diagram showing another embodiment of the present invention.

FIG. 4 is a block diagram showing another embodiment of the present invention.

5 is an explanatory diagram for explaining the operation of the embodiment of FIG.

FIG. 6 is a block diagram showing another embodiment of the present invention.

FIG. 7 is a block diagram showing another embodiment of the present invention.

FIG. 8 is an explanatory diagram for explaining the operation of the embodiment of FIG.

FIG. 9 is a block diagram showing a second generation EDTV encoder.

FIG. 10 is a block diagram showing a second generation EDTV decoder.

[Explanation of symbols]

 81 ... Delay circuit, 82 ... EDTV determination circuit, 83 ... Selector

Claims (4)

[Claims] 1. A wide television signal and a current television signal in which a compensation signal for compensating a main screen signal corresponding to a main screen portion in the center of the screen is multiplexed in a period corresponding to a non-picture portion above and below the screen. A method determining unit that determines which is input through an input terminal and outputs a gate signal that distinguishes a period corresponding to the main screen portion and a period corresponding to the non-image portion, and the input terminal A luminance signal / color signal separating means for separating a television signal input via the luminance signal and a color signal, and a television signal input to the input terminal without passing through the luminance signal / color signal separating means. When a through signal to be output and a gate signal indicating that the period corresponding to the main screen portion is input from the method determining unit, the luminance signal
The luminance signal and the color signal from the color signal separating means are output to the luminance signal system and the color signal system, respectively, and when the gate signal indicating the period corresponding to the non-image portion is input, the output of the through path is output. A multiple signal correction circuit, comprising: selecting means for outputting to the luminance signal system or the color signal system in place of the luminance signal or the color signal from the luminance signal / color signal separating means. 2. A wide television signal and a current television signal in which a compensation signal for compensating a main screen signal corresponding to the main screen portion in the center of the screen is multiplexed in a period corresponding to the non-picture portions above and below the screen. A method determining unit that determines which is input through an input terminal and outputs a gate signal that distinguishes a period corresponding to the main screen portion and a period corresponding to the non-image portion, and the input terminal 1 for the television signal input via
A luminance signal / color signal separating means for separating a luminance signal by adding a delayed signal delayed by a frame period and the input television signal and a color signal by subtraction, and a television signal input to the input terminal. A through path for outputting without passing through the luminance signal / color signal separating means, a non-picture part motion judging means for judging the motion of the non-picture part, and a period corresponding to the main screen part from the system judging means. When a gate signal indicating that
The luminance signal and the color signal from the color signal separating means are output to the luminance signal system and the color signal system, respectively, and when the gate signal indicating the period corresponding to the non-image portion is input, the non-image portion moves. When it is determined by the determination means that the non-image part is a moving image, the output of the through path is replaced with the luminance signal or the color signal from the luminance signal / color signal separation means, and the luminance signal system or color. While outputting to the signal system,
And a selection means for outputting the addition result of the luminance signal / color signal separation means to the luminance signal system when the non-image portion movement determination means determines that the non-image portion is a still image. A multiple signal correction circuit characterized by: 3. The multiple signal correction circuit according to claim 2, wherein the non-image part motion determination means uses a motion detection result for the main screen part. 4. The multiplex according to claim 2, wherein the non-image part motion determination means performs a motion determination by rearranging a motion detection result for the main screen part in association with the non-image part. Signal correction circuit.