JPH0435490A - Video signal processor - Google Patents

Abstract

PURPOSE:To obtain a video signal processor which is of small circuit configuration and profitable in a viewpoint of cost by generating a high band luminance signal for obtaining a composite video signal to meet an EDTV system in the video signal processor, and summing and synthesizing this high band luminance signal directly with the composite video signal supplied from a video camera main body, and outputting this synthesized signal. CONSTITUTION:In a matrix circuit 17 and a gamma correction circuit 18, a luminance signal is synthesized from three-primary-colors signals not having been gamma-corrected, and this luminance signal is gamma-corrected, and the luminance signal Y0 is generated. Next, is an ED signal generation circuit 21, the high band luminance signal which is the high band component of the luminance signal Y given level correction processing corresponding to the signal level ratio of the luminance signal Y and the luminance signal Y0 is formed, and in an addition and synthesis circuit 45, the composite video signal supplied from the video camera main body and the above-mentioned high band luminance signal are summed and synthesized and outputted. Thus, the composite video signal to meet the EDTV (Extended Definition TV) system can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Application Field The present invention is applicable to so-called HD TV (Extended Detailed Description)
The present invention relates to a video signal processing device that can obtain a composite video signal compatible with the HDTV (finition TV) system, and relates to a video signal processing device that is connected to a video camera body, for example.

B6 Summary of the Invention The video signal processing device according to the present invention is a video signal processing device to which three primary color signals and a composite video signal formed from the three primary color signals subjected to nonlinear level compression processing are input. a first luminance signal synthesized from the processed three primary color signals from the input three primary color signals;
a second luminance signal forming means for forming a second luminance signal subjected to non-linear level compression processing from the input three primary color signals; and a level correction process of the first brightness signal according to the signal level ratio of the first brightness signal from the first brightness signal forming means and the second brightness signal from the second brightness signal forming means. comprising a high-frequency luminance signal forming means for forming a high-frequency luminance signal applied to the high-frequency component; and an additive synthesis means for adding and synthesizing the input composite video signal and the high-frequency luminance signal from the high-frequency luminance signal forming means; By outputting a composite video signal that has been subjected to constant brightness signal processing from the addition/synthesis means, it is possible to generate a composite video signal based on the EDTv method without the need for a synchronization signal generation circuit, a color coder, etc. in the video signal processing device. It is made so that it can be obtained.

C0 Conventional Technology It has been more than 30 years since the current NTSC system was established for television broadcasting, and in recent years television receivers have become larger and brighter, and video signals, which are high-quality signal sources, have become larger and brighter. With the advent of tape recorders, video discs, etc., the shortcomings of the NTSC system have become more noticeable.

For example, cathode ray tubes (C
Due to the substantial increase in gamma value accompanying the increase in the brightness of RT), the overall input/output characteristics deteriorate in dark areas, resulting in deterioration in the reproducibility of brightness details in dark areas of images. Furthermore, due to the limited transmission band of color signals, deterioration of luminance definition occurs in high chroma portions of images.

For this reason, various studies have been conducted to improve the image quality of television broadcasting, and while ensuring compatibility with the current television system, improvements to signal sources and adaptation that have a large improvement effect and are relatively easy to implement have been conducted. The so-called first generation EDTV system, which aims to eliminate emphasis (commonly known as S1), gamma correction compensation (constant brightness signal processing, commonly known as Y3), and ghosts, has come into practical use.

Improvements in the signal source described above can be achieved by using a video camera that has a higher resolution than current video cameras, a progressive scan video camera, or a high-visibility video camera. Further, the adaptive emphasis can be achieved by reducing the emphasis on the high frequency range when the amplitude of the low frequency component of the video signal is large, and by reducing the emphasis when the amplitude of the low frequency component is small. Furthermore, compensation for gamma correction can be achieved by using a compensation circuit to compensate in advance for resolution degradation of the high chroma image due to gamma correction on the transmitting side. In addition, in the above ghost removal, a ghost removal reference signal is superimposed on a TV signal and broadcast on the transmitting side, and the receiving side detects the intensity and time deviation from the ghost removal reference signal, and receives the signal so that these are minimized. This can be achieved by performing signal processing.

Incidentally, in some conventional video cameras, a circuit for compensating for adaptive emphasis and gamma correction is attached to the video camera body as an adapter device, so that the conventional video camera body can be used as is.

Here, a conventional video signal processing device W (hereinafter referred to as an adapter device) for a video camera will be explained with reference to FIG.

First, the color coder 60 of the video camera body will be briefly explained.

As shown in FIG. 4, the three primary color signals that have been gamma-corrected in a so-called process circuit, that is, the R signal, G signal, and B signal (hereinafter referred to as RC and B signals), are sent to terminals 5I and 52, respectively.
．． 53 to the color coder 60 of the video camera body.

The matrix circuit 61 of the color coder 60 has the above R
A luminance signal Y and a color signal (referred to as ■ signal and Q signal) are synthesized from the GB signals, and the luminance signal Y is sent to a delay circuit 62, and the 1 signal and Q signal are respectively sent to low-pass filters (hereinafter referred to as LPF) 63 and 65. send.

The LPF 63 limits the band of the I signal, and the LPF 65
limits the band of the Q signal. This one band-limited signal is sent to the balanced modulation circuit 66 via the delay circuit 64,
The band-limited Q signal is sent directly to the balanced modulation circuit 66.

The balanced modulation circuit 66 amplitude-modulates the subcarriers having different phases from the synchronization signal generation circuit 68 using the band-limited I signal and Q signal, respectively, to generate a carrier color signal. This carrier color signal is sent to an adder circuit 67.

The adder circuit 67 receives the luminance signal Y from the delay circuit 62.
The carrier color signal from the balanced modulation circuit 66 is superimposed on the signal, and the color burst signal from the synchronization signal generation circuit 68 is multiplexed to form a composite video signal conforming to the NTSC system, a so-called composite signal. This composite video signal is output from terminal 54.

A conventional adapter device 7O that is connected to a video camera having the color coder 60 configured as described above and forms a composite video signal compatible with the EDTV system is supplied from the video camera body as shown in FIG. ED that generates the above-mentioned gamma correction compensation component and adaptive emphasis emphasis component from the RGB signal that has been subjected to gamma correction.
A signal generation circuit 80, a color coder 90 that forms a composite video signal from the ROB signal, and adds and synthesizes a gamma correction compensation component etc. from the ED signal generation circuit 80 to the composite video signal; It is composed of a synchronization signal generation circuit 100 and the like that generates various synchronization signals synchronized (genlocked) with the above-mentioned composite video signal sent, and outputs a composite video signal compatible with the EDTV system.

Specifically, the gamma-corrected RGB signals supplied via the terminals 51, 52, and 53 are sent to the connection terminals 1.2.
．． 3 to the inverse gamma correction circuit 71 and the matrix circuit 91 of the color coder 90, and the composite video signal formed by the color coder 60 of the video camera body is supplied to the synchronization signal generation circuit via the connection terminal 4. 1
00.

The above-mentioned inverse gamma correction circuit 71 performs the RG after the above-mentioned gamma correction.
Applying reverse gamma correction to the B signal, RG before this gamma correction
The B signal is sent to the matrix circuit 72.

The matrix circuit 72 synthesizes a luminance signal from the RGB signals before gamma correction, and sends this luminance signal to the gamma correction circuit 7.
Send to 3.

The gamma correction circuit 73 performs gamma correction on the luminance signal, and sends the gamma-corrected luminance signal to the ED signal generation circuit 80. Here, the luminance signal obtained by gamma-correcting the freshness signal obtained from the RGB signals before gamma correction is referred to as the luminance signal Y0 obtained from the RGB signals before gamma correction.

On the other hand, the ED signal generation circuit 80 generates a luminance signal Y0 obtained from the RGB signal before gamma correction from the gamma correction circuit 73 and the ROB signal after gamma correction from the matrix of the color coder 90 and the matrix circuit 91. A compensating component for gamma correction is generated based on this ratio, and a low-frequency component of the luminance signal Y is extracted, and an emphasis component for adaptive emphasis is generated based on the amplitude of this low-frequency component. At the same time, a signal (hereinafter referred to as a clear vision signal) is generated by adding the compensation component and emphasis component of these gamma corrections. This clear vision signal is then supplied to the adder circuit 98 of the color coder 90.

The synchronization generation circuit 100 generates synchronization signals such as subcarriers and color burst signals used when forming a composite video signal in the color coder 90 from the composite video signal supplied from the color coder 60 of the video camera body. . This subcarrier is supplied to the balanced modulation circuit Fa96 of the color coder 90, and the color burst signal is supplied to the adder circuit 97.

The color coder 90 has almost the same circuit configuration as the color coder 60 of the video camera body described above, and combines the luminance signals Y, ■, and Q signals in the matrix circuit 91, and The adder circuit 98 adds the above ED to the luminance signal Y from the matrix circuit 91.
After adding the clear vigilance signal from the signal generation circuit 80, the addition circuit 97 superimposes the carrier color signal from the balanced modulation circuit 96 on the luminance signal Y, which has been added and synthesized with the clear vision signal. 1
The color burst signals from 00 are multiplexed to form a composite video signal compatible with the EDTV system, and this composite video signal is outputted via the terminal 75.

D0 Problems to be Solved by the Invention Incidentally, in the conventional adapter device 70 described above, as shown in FIG. The adapter device 70 requires a signal generation circuit 100 and a color coder 90 that forms a composite video signal.
The whole video camera with this addition was a very unreasonable and wasteful system.

Further, for example, in an adapter device used in a video camera that can supply various synchronization signals such as subcarriers and color burst signals to the outside, the synchronization signal generation circuit 100 is not necessary, but the color coder 90 is still necessary. Furthermore, it required connection means to receive and receive various synchronization signals, making the system unreasonable.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a video signal processing device that has a smaller circuit scale and is more cost-effective than conventional devices.

80 Means for Solving the Problems A video signal processing device according to the present invention is a video signal processing device to which three primary color signals and a composite video signal formed from the three primary color signals subjected to nonlinear level compression processing are input. , a first luminance signal synthesized from the three primary color signals subjected to the nonlinear level compression processing from the input three primary color signals.
and a second luminance signal forming means for forming a second luminance signal from the input three primary color signals by performing nonlinear level compression processing on the luminance signal obtained by combining the three primary color signals that have not been subjected to the nonlinear level compression processing. and a level correction process according to a signal level ratio between a first luminance signal from the first luminance signal forming means and a second luminance signal from the second luminance signal forming means. A high-frequency luminance signal forming means for forming a high-frequency luminance signal applied to the high-frequency component of the luminance signal, and an additive synthesis means for adding and synthesizing the input composite video signal and the high-frequency luminance signal from the cough high-frequency luminance signal forming means. The above-mentioned problem SI is solved by outputting a composite video signal subjected to constant brightness signal processing from the above-mentioned addition/synthesis means.

F0 action In the video signal processing device according to the present invention, a high-frequency luminance signal for obtaining a composite video signal compatible with the EDTV system is generated within the video signal processing device, and a composite signal supplied from a video camera body, for example, is generated. The video signal and this high-frequency luminance signal are directly added together and output.

G. Embodiments Hereinafter, embodiments of the video signal processing apparatus according to the present invention will be described with reference to the drawings.

As shown in FIG. 1, the video signal processing device (hereinafter referred to as an adapter device) 10 of the first embodiment performs nonlinear level compression processing, that is, gamma correction, on input three primary color signals supplied from the video camera body. A matrix circuit 11 that synthesizes the luminance signal Y, generates three primary color signals without gamma correction from the input three primary color signals, synthesizes a luminance signal from the three primary color signals, performs gamma correction on this luminance signal, and generates a luminance signal. A reverse gamma correction circuit 12, a matrix circuit 3 and a gamma correction circuit 14, which generate Y0, perform level correction processing on the high-frequency components of the luminance signal Y in accordance with the signal level ratio of the luminance signal Y and the luminance signal Y0. an ED signal generation circuit 20 that forms a high-frequency luminance signal, and an addition and synthesis circuit 40 that adds and synthesizes the input composite video signal supplied from the video camera body and the high-frequency luminance signal,
A composite video signal subjected to constant brightness signal processing is output from the addition/synthesis circuit 40.

Specifically, as shown in FIG. 1, gamma-corrected three primary color signals are transmitted through connection terminals 1, 2, and 3 that connect the color coder 60 of the video camera body and the adabuk device 10, respectively. R signals, G signals, and B signals (hereinafter referred to as RGB signals after gamma correction) are supplied to the matrix circuit 11 and the inverse gamma correction circuit 12, and the signals obtained from the RGB signals subjected to gamma correction are obtained via the connection terminal 4. The composite video signal obtained is supplied to the addition/synthesis circuit 40.

The matrix circuit 11 synthesizes a luminance signal Y from the RGB signals, and sends the luminance signal Y obtained by synthesizing the gamma-corrected RGB signals to the ED signal generation circuit 20.

On the other hand, the inverse gamma correction circuit 12 performs inverse gamma correction on the RGB signals after the gamma correction, and
0 signal, G0 signal, B0 signal (hereinafter RG before gamma correction)
This RGB signal before gamma correction is sent to the matrix circuit 13.

The matrix circuit 13 synthesizes a luminance signal from the RGB signals before gamma correction, and sends this luminance signal to the gamma correction circuit 14.

The gamma correction circuit 4 performs gamma correction on the luminance signal from the matrix circuit 13, and the gamma-corrected luminance signal (hereinafter referred to as luminance signal Y).

) is sent to the ED signal generation circuit 20.

The ED signal generation circuit 20 includes, for example, as shown in FIG. 2, a gamma correction compensation circuit 25 that generates a gamma correction compensation component, an adaptive emphasis circuit 26 that generates an adaptive emphasis emphasis component, and an adaptive emphasis circuit 26 that generates an adaptive emphasis component. The matrix circuit 11 shown in FIG.
Luminance signal Y obtained from the RGB signal after gamma correction from 814 and RGB before gamma correction from 814 before gamma correction
The luminance signal Y0 obtained from the signal is connected to the terminal 22.2, respectively.
3.

The gamma correction compensation circuit 25 includes a low-pass filter (
(hereinafter referred to as LPF) 25a, 25c, addition circuit 25b,
Consisting of a division circuit 25d and a multiplication circuit 25e, the luminance signal Y obtained from the gamma-corrected ROB signal supplied via the terminal 22 is transmitted to the LPF 25a and the addition circuit 25.
The luminance signal Y0 obtained from the ROB signal before gamma correction supplied through the terminal 23 to the L
It is supplied to PF25c.

The LPF 25a extracts the low frequency component of the luminance signal Y obtained from the RGB signal after gamma correction, and sends this low frequency component to the addition circuit 25b and the division circuit 25d.

The LPF 25c is a luminance signal Y obtained from the RGB signals before gamma correction. , and sends this low-frequency component to the division circuit 25d.

The division circuit 25d divides the low frequency component of the luminance signal Y obtained from the RGB signal after gamma correction and the RG before gamma correction.
Luminance signal Y obtained from signal B.

The ratio of the low frequency components is determined and this ratio is sent to the multiplication circuit 25e.

The adder circuit 25b subtracts the low-frequency component of the luminance signal Y from the LPF 25a from the luminance signal Y supplied via the terminal 22, extracts the open-air component of the luminance signal Y, and multiplies this high-frequency component by the multiplication described above. It is sent to circuit 25e.

The multiplication circuit 25e multiplies the high-frequency component of the luminance signal Y from the addition circuit 25b by the ratio to generate a compensation component for gamma correction, and the compensation component for gamma correction is sent to the addition circuit 2.
Send to 7.

That is, the gamma correction compensation circuit 25
The low frequency component of the luminance signal Y from F25a and the above LPF25
Luminance signal y from c. 0) The ratio of the low frequency components is determined by the division circuit 25d, and the multiplication circuit 25e forms a high frequency luminance signal in which the high frequency components of the luminance signal Y are subjected to level correction processing according to this ratio. In other words, the gamma correction compensation circuit 25 generates a compensation component that emphasizes the high frequency component of the luminance signal Y of the high chroma image.

On the other hand, the adaptive Yu/F/S circuit 26 includes a high-pass filter (hereinafter referred to as HPF) 26a, an LPF 26b, an emphasis constant circuit 26c, and a control circuit 26d.
The luminance signal Y obtained from the GB signal is transmitted to the HPF 26a, .
It is supplied to the LPF 26b.

The HPF 26a extracts a high frequency component of the luminance signal Y obtained from the RGB signal after the gamma correction, and sends this high frequency component to the emphasis constant circuit 26c.

The LPF 26b extracts a low frequency component of the luminance signal Y obtained from the RGB signal after gamma correction, and sends this low frequency component to the control port flII 26d.

The control circuit 26d controls the emphasis constant circuit 26c based on the low frequency component of the luminance signal Y.

That is, the adaptive emphasis circuit 26
The low frequency component of the luminance signal Y is extracted in b, and the emphasis constant 11826c is controlled by the control circuit 26d based on the amplitude of this low frequency component, and when the amplitude of the low frequency component is large, the emphasis on the high frequency is reduced. However, when the amplitude of the low frequency component is small, an emphasis component is generated that increases the emphasis on the high frequency range.

The gamma correction compensation component from the gamma correction compensation circuit 25 and the emphasis component from the adaptive emphasis circuit 26 are supplied to the addition circuit 27 and added, and this addition result (hereinafter referred to as a clear vision signal) is sent to the terminal 24. The signal is then supplied to the addition/synthesis circuit 40 shown in FIG. 1 above.

As shown in FIG. 1, the addition and synthesis circuit 40
The clear visitor signal is directly added to and synthesized with the composite video signal supplied via the connection terminal 4 to form a composite video signal compatible with the EDTV system, and this composite video signal is output from the terminal 41.

Note that the color coder 60 of the video camera body is connected to terminal 5.
Gamma corrected RG supplied via 1.52.53
Although it has the function of forming a composite video signal from the B signal, it has a circuit configuration similar to that of the color coder 60 of the video camera body shown in FIG. 4 described above, so a description thereof will be omitted.

As described above, the adapter device 10 synthesizes the luminance signal Y from the RGB signals subjected to gamma correction in the matrix circuit 11, that is, the three primary color signals subjected to gamma correction, and also synthesizes the luminance signal Y from the RGB signals subjected to gamma correction in the matrix circuit 11. 13 and gamma correction circuit 14, three primary color signals without gamma correction are generated from the three primary color signals, a luminance signal is synthesized from the three primary color signals, and gamma correction is performed on this luminance signal to form a luminance signal Y. do.

Next, the ED signal generation circuit 20 generates a high-frequency luminance signal in which the high-frequency component of the luminance signal Y is subjected to level correction processing according to the signal level ratio between the luminance signal Y and the luminance signal Y0. Then, by adding and synthesizing the input composite video signal supplied from the video camera body and the above-mentioned high-frequency luminance signal in the addition/synthesizing circuit 40, a composite video signal that has been subjected to constant luminance signal processing, that is, an EDTV system It is possible to form a composite video signal corresponding to

In other words, it is possible to form a composite video signal compatible with the EDTV system without requiring a color coder, a synchronization signal generation circuit, etc. unlike the adapter device, which is a conventional video signal processing device.

Next, a second embodiment of the video signal processing device according to the present invention will be described using a third region.

In the adapter device 10 of the first embodiment described above, the three primary color signals that have been subjected to non-linear level compression processing, that is, gamma correction, are supplied from the video camera body. (referred to as adapter device)3
At 0, three primary color signals without gamma correction are supplied from the video camera body. Therefore, as shown in FIG. 3, the adapter device 30 performs gamma correction on the primary color signals that have not been subjected to gamma correction supplied from the video camera body, and synthesizes the luminance signal Y from the three primary color signals. Correction circuit 15 and matrix circuit 16
, a matrix circuit 17 and a gamma correction circuit 18 that synthesize a luminance signal from the three primary color signals that have not been subjected to gamma correction, perform gamma correction on this luminance signal to form a luminance signal Y0, and synthesize the luminance signal Y and luminance. An ED signal signal generation circuit 21 that forms a high-frequency luminance signal in which the high-frequency component of the luminance signal Y is subjected to level correction processing according to the signal level ratio with the signal Y0, and a composite video signal supplied from the video camera body. Additive synthesis circuit 45 that adds and synthesizes the above-mentioned high-frequency luminance signal
The composite video signal which has been subjected to constant brightness signal processing is sent to the addition/synthesis port 1! ! It is designed to output from 45.

Specifically, as shown in FIG. 3, three primary color signals, which have not been subjected to gamma correction, are transmitted through connection terminals 5, 6, and 7 that connect the color coder 60 of the video camera body and the adapter device 30, respectively. R0 signal, G0 signal, B0
A signal (hereinafter referred to as an RGB signal before gamma correction) is supplied to the gamma correction circuit 15 and the matrix circuit 17,
A composite video signal formed from the three primary color signals subjected to gamma correction in the color coder 60 of the video camera body is supplied to the addition/synthesis circuit 45 via the connection terminal 8.

The gamma correction circuit 15 performs gamma correction on the three primary color signals that have not been subjected to gamma correction and is supplied via the connection terminal 5.6.7, and the gamma correction circuit 15 performs gamma correction on the three primary color signals that have undergone gamma correction, that is, the R signal, the G signal, and The B signal (hereinafter referred to as RGB signal after gamma correction) is sent to the matrix circuit 16.
send to

The matrix circuit 16 receives the ROB after the gamma correction.
The luminance signal Y is synthesized from the signals, and this gamma-corrected RG
A luminance signal Y obtained by combining the B signals is sent to the EDD signal generation circuit 21.

On the other hand, the matrix circuit 17 synthesizes a luminance signal from the RGB signals before gamma correction, and sends this luminance signal to the gamma correction circuit I8.

The gamma correction circuit 18 performs gamma correction on the luminance signal from the matrix circuit 17, and sends this gamma-corrected luminance signal (hereinafter referred to as luminance signal Y0) to the EDD.
The signal is sent to the signal generating circuit 21.

The EDD signal generation circuit 21 has a circuit configuration equivalent to the ED signal generation circuit 20 of the first embodiment, that is, the circuit configuration shown in FIG. By the same operation as the circuit 20, a clear vision signal is generated from the luminance signal Y and the luminance signal Y0, and this clear vision signal is sent to the addition and synthesis circuit 45.

The addition and synthesis circuit 45 directly adds and synthesizes the clear vision signal to the composite video signal supplied via the connection terminal 8 to form a composite video signal compatible with the EDTV system, and sends this composite video signal to the terminal. Output from 46.

Note that the gamma correction circuit 69 of the video camera body receives the R signal before gamma correction supplied via the terminals 55, 56, 57.
Apply gamma correction to the GB signal. The color coder 60 has the function of forming a composite video signal from the RGB signals after gamma correction, and has the same circuit configuration as the color coder 60 of the video camera body shown in FIG. 4 described above. The explanation will be omitted.

As described above, in the adapter device 30, when the RGB signal without gamma correction is supplied from the video camera body, that is, the three primary color signals without gamma correction, the gamma correction circuit 15 and the matrix circuit 16
Gamma correction is performed on the three primary color signals that have not been subjected to gamma correction, and a luminance signal Y is synthesized from these three primary color signals. The signals are combined and gamma correction is performed on this luminance signal to form a luminance signal Y0.

Next, in the EDD signal generation circuit 21, the luminance signal Y
The high frequency component of the brightness signal Y is subjected to level correction processing according to the signal level ratio of the brightness signal Y and the brightness signal Y! + forms a high-frequency luminance signal. Then, by adding and synthesizing the composite video signal supplied from the video camera body and the above-mentioned high-frequency luminance signal in the addition/synthesizing circuit 45, a composite video signal subjected to constant luminance signal processing, that is, a composite video signal of the EDTV system, is produced. A corresponding composite video signal can be formed. In other words, EDT does not require a color coder or synchronization signal generation circuit unlike the adapter device, which is a conventional video signal processing device.
A composite video signal compatible with the V format can be formed.

Note that the present invention is not limited to the above embodiments,
For example, it may be used as an adapter device such as a video tape recorder, that is, a video signal processing device.

H1 Effects of the Invention As is clear from the above explanation, in the video signal processing device according to the present invention, the first luminance signal synthesized from the three primary color signals subjected to nonlinear level compression processing in the first luminance signal forming means. is formed from the input three primary color signals, and a second luminance signal is obtained by performing nonlinear level compression processing on the luminance signal obtained by synthesizing the three primary color signals that have not been subjected to nonlinear level compression processing in a second luminance signal forming means. and in the high-range luminance signal forming means, the signal level is determined according to the signal level ratio of the first luminance signal from the first luminance signal forming means and the second luminance signal from the second luminance signal forming means. A high-frequency luminance signal is formed by applying level correction processing to the high-frequency component of the luminance signal, and the addition and synthesis means adds the input composite video signal and the high-frequency luminance signal from the cough high-frequency luminance signal forming means. By combining and outputting, it is possible to output a composite video signal subjected to constant brightness signal processing. That is, it is possible to obtain a composite video signal subjected to constant brightness signal processing, that is, a composite video signal compatible with the EDTVD format, without requiring a color coder or a synchronization circuit within the video signal processing device. In other words, it is possible to realize a video signal processing device with a smaller circuit scale, lower cost, and lower power than conventional ones.

[Brief explanation of drawings]

FIG. 1 is a block circuit diagram of a first embodiment of a video signal processing device according to the present invention, and FIG. 2 is a block circuit diagram of an EDD signal generation circuit provided in the video signal processing device. 3 is a block circuit diagram of the second embodiment, and the fourth embodiment is a block circuit diagram of the second embodiment.
The figure is a block circuit diagram of a conventional video signal processing device. ]1.13.16.17 ... Matrix circuit 1
2 . . . reverse gamma correction circuit 14.15.18 , . . . gamma correction circuit 20/21
...ED signal generation circuit 4045 ...addition synthesis circuit 2,

Claims (1)

[Scope of Claims] A video signal processing device to which three primary color signals and a composite video signal formed from the three primary color signals subjected to nonlinear level compression processing are input, the video signal processing device comprising: a composite video signal formed from the three primary color signals subjected to nonlinear level compression processing; A first luminance signal forming means that forms a synthesized first luminance signal from the input three primary color signals, and a second luminance signal forming means that performs nonlinear level compression processing on the luminance signal that is the composite of the three primary color signals that have not been subjected to nonlinear level compression processing. a second luminance signal forming means for forming a luminance signal from the input three primary color signals; a first luminance signal from the first luminance signal forming means and a second luminance signal from the second luminance signal forming means; a high-frequency luminance signal forming means for forming a high-frequency luminance signal in which a high-frequency component of the first luminance signal is subjected to level correction processing according to a signal level ratio between the input composite video signal and the high-frequency luminance signal; 1. A video signal processing device, comprising: an addition/synthesis means for adding and synthesizing a high frequency luminance signal from a forming means, and outputting a composite video signal subjected to constant luminance signal processing from the addition/synthesis means.