JPH02180474A - Television signal processor - Google Patents

Abstract

PURPOSE:To discriminate difference in the system of an input television signal by comparing the standard system of the television signal with the frequency distribution of the high resolution television signal, for example, to which band compression is executed, extracting the some kinds of parts, in which the frequency distribution is different, and comparing the signals. CONSTITUTION:For a detection output signal inputted to an input terminal 21 of a detection circuit 12, the respective components of a frequency area B (near 4.8MHz), frequency area D (near 9.5MHz) and frequency area E (near 5.7MHz) are respectively extracted by BPFs 22, 23 and 24. The level of a signal in the frequency area B is compared with the level of the signal in the frequency area E by a comparator 28. When the signal level of the frequency area E is larger than the signal level of the frequency area B, the detection signal is outputted to show that the input television signal is an NTSC system. When the frequency area B is compared with the frequency signal D and the signal level of the frequency area B is larger than the signal level of the frequency area D, the detection signal is outputted to show that the input television signal is a band compression transmission system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a television signal for discriminating between, for example, a band-compressed high-resolution television signal and a standard format (for example, NTSC format) television signal. The present invention relates to a signal processing device.

[Summary of the invention]

The present invention has detection means for detecting the difference in frequency distribution between a band-compressed high-definition television signal and a standard television signal. To make it possible to reliably distinguish between a band-compressed television signal and a standard format television signal even if the content is not accurately demodulated.

[Conventional technology]

Television signal transmission systems using broadcasting satellites include the standard NTSC system and a band-compressed high-resolution television signal transmission system.

In the above NTSC system, for example, the frequency bands are 6, 2
MHz, the number of scanning lines is 525, and the aspect ratio is 4:3. On the other hand, various transmission methods are currently being proposed for the above-mentioned high-resolution television signals, and one example of such a transmission method is the so-called MUSE (Multiple Sub-Nyquist Sampling Encoding) method, which has a frequency band of 32.5 MH2. , the number of scanning lines is 1125, and the aspect ratio is 16:9, so there are considerable differences between the two systems. Here, most of the television receivers currently popular in general households reproduce the above-mentioned NTSC system television signals, so if the above-mentioned high-resolution TV broadcasting is started in the future, It is necessary for an NTSC television receiver to be able to reproduce the band-compressed high-resolution television signal. For this reason, various technologies are currently being developed to convert the above-mentioned band-compressed high-resolution television signals into NTSC television signals, and in the future, it will be possible to convert the band-compressed high-resolution television signals into NTSC television signals. It is conceivable that system conversion will be possible.

By the way, if satellite broadcasting using the above-mentioned high-definition television signal is started, it may be possible to set up a dedicated channel, but even though it is the same channel, the above-mentioned N
It is also expected that both TSC television signals and high-definition television signals will be received. Therefore, in order to view transmission signals of one system on a television receiver of the other system, means for converting the system is required, and at the same time, means for discriminating between both systems is required.

As an example of a currently proposed device for discriminating both types as described above, there is a device having a configuration as shown in FIG. 8, for example.

That is, in Fig. 8, S of a parabolic antenna, etc.
The N received by the HF receiving antenna 101
Satellite broadcast radio waves of TSC television signals or high-resolution television signals are supplied to a tuner circuit 102 serving as a satellite broadcast receiving circuit. The tuner circuit 102 performs various processing such as tuning and detecting the satellite broadcasting waves, and supplies a detection output signal to a decoder 103 that decodes the high resolution television signal.

The decoder 103 converts the detection output signal of the NTSC television signal or high resolution television signal from the tuner circuit I02 into R, G, and B signals.

Here, the above-mentioned high-resolution television signal has an AFC (
The difference is that there is a key pulse (for example, 60 Hz) for NTSC (Automatic Frequency Control), and an NTSC television signal has an AFC signal but no key pulse. Therefore, the AFC key pulse is detected only when the television signal input to the decoder 103 is the high resolution television signal. That is, the presence or absence of the key pulse is detected and the detected signal is transmitted to the tuner circuit 1102.

The tuner circuit 102 receives the AF signal from the decoder 103.
Based on the C key pulse, a signal for determining whether the signal is an NTSC television signal or a high resolution television signal is transmitted to the center microcomputer 104, and the center microcomputer 104 controls each part of the television receiver. A controlling IIJIB signal is output.

In the case of the NTSC television signal, since there is no AFC key pulse, the detection signal is not transmitted to the tuner circuit 102 and is directly converted into R, G, and B signals and output.

[Problem to be solved by the invention]

Currently, NTSC television signals and high-resolution television signals are distinguished as described above.
This method has the following drawbacks.

First, the current method has a slow detection rise time, which may pose a practical problem. That is, the above SHFHF
The television signal received by the receiving antenna 1 is
Even though it has already been input to the tuner circuit 102, the detection rise time from when the decoder 103 detects the AFC key pulse to when the tuner circuit 102 outputs it as a discrimination signal is 1 second to 1.5 seconds. It is very slow, about seconds. This means that if, for example, the transmission method suddenly changes while the television receiver is monitoring the image, the image on the television receiver will disappear or become distorted for the above detection rise time. The detection rise time is similarly delayed not only for the television signal received by the SHFHF receiving antenna 1 but also for the television signal input from the external input terminal.

Second, the modulation content needs to be demodulated. That is, C
/N is bad (or when the radio waves are weak), even if the tuner circuit 102 barely obtains a detection output, the level of the key pulse of the AFC is insufficient and the key
It may happen that the pulse cannot be demodulated.

Also, as mentioned above, the AFC key pulse can be used to
Apart from the method of distinguishing between a TSC television signal and a high-resolution television signal, the decoder 103 is not used, but a separate microcomputer and digital circuit are used to detect the 60Hz signal that exists only in the high-resolution television signal.
A method for detecting frame synchronization pulses has been proposed. However, in this case as well, since the frame synchronization pulse is detected from the tuner's detection output signal as in the above-described method, if the C/N is poor or the radio waves are weak, the frame synchronization pulse may be disturbed. Furthermore, this method requires a separate microcomputer and digital circuit, resulting in a complex circuit configuration and high cost.

The present invention was proposed in view of the above-mentioned circumstances, and is a method for modulating N, TSC television signals and band-compressed high-resolution television signals with a simple and inexpensive circuit configuration. The object of the present invention is to provide a television signal processing device that does not require accurate demodulation of the content, has more reliable discrimination operation even under poor C/N conditions, and can make discrimination in a short time. be.

[Means to solve the problem]

The present invention has been proposed to achieve the above-mentioned object, and uses a band-compressed, for example, high-definition television signal having a substantially uniform frequency distribution within a transmission band, and a standard format television signal. A television signal processing device for discriminating between the standard type television signal and the band-compressed, for example, high-resolution television signal, comprising a detection means for detecting a difference in frequency distribution between the standard type television signal and the band-compressed, for example, high-resolution television signal. It is something.

[Effect]

According to the present invention, the frequency distribution of a standard television signal and a band-compressed, for example, high-definition television signal are compared, and several different parts of the frequency distribution are extracted and compared. It distinguishes between different signal systems.

[Embodiment] First, a schematic configuration of a television signal processing device of the present invention will be described with reference to FIG.

That is, in FIG. 1, the input terminal 11 of the television signal processing device 3 receives a television signal of a band compression transmission method or a television signal of a standard method having a substantially uniform frequency distribution within the transmission band. and a detection circuit 12 for detecting the difference in frequency distribution between the standard type television signal and the band compression transmission type television signal, and a reproducing circuit 12 for performing reproduction processing of the television signal. The data is transmitted to the processing circuit I3. A detection signal in the format of the input television signal is output from the detection circuit 12 and transmitted to the reproduction processing circuit 13. The reproduction processing circuit 13 reproduces the television signal of the standard method or band compression transmission method based on the detection signal. In the illustrated example, a television signal received from, for example, a satellite broadcast radio wave through an SHFHF receiving antenna 1 and a tuner circuit 2 is supplied to the input terminal 11.

A specific embodiment of the present invention shown in FIG. 1 will be described below. Here, in this embodiment, for example, the so-called MUSE method described above is assumed as an example of a method for compressing and transmitting a high-resolution television signal (bandwidth compression transmission method), but the method is limited to this method. It's not a thing.

As described above, in the television signal processing device of the present invention, since the discrimination is made by detecting the difference in frequency distribution, the tuner circuit 2 first receives the satellite broadcast radio waves of the NTSC system and the band compression transmission system. The differences in the frequency distribution of the detected output signal (of the television signal) are shown in Figures 2 to 4.
This will be explained with reference to the figures.

FIG. 2 shows the frequency distribution when the satellite broadcast radio waves are television signals of the band compression transmission method. As shown by curve a in the figure, the television signal of the above-mentioned band compression transmission method is about 8. It shows a -like frequency distribution in the range up to I M II z.

Although this frequency distribution may change slightly depending on the video content, the characteristic that the frequency distribution is -like remains the same.
Furthermore, since there are many rectangular pulses even when there is no image, as shown by the curve in the figure, the above-mentioned path 8. A signal component having a substantially uniform frequency component in the range up to IMHz remains and can be clearly distinguished from the noise component. Therefore, it is easy to distinguish it from outside the band.

Figure 3 shows the case where the satellite broadcasting radio waves are NTSC television signals, and the frequency of the color subcarrier is 3,58.
This shows a frequency distribution with high signal levels in the band around MH2 and around 5"13M11z, which is the frequency band of the 4-phase PSK audio signal for satellite broadcasting. Note that this video signal varies somewhat depending on the video content. It is something to do.

On the other hand, if the satellite broadcast radio waves are not input to the tuner circuit 2, that is, the frequency distribution of only noise components, theoretically a --like (but low level) frequency distribution from O to ωHz is expected. It shows.

FIG. 4 shows a frequency distribution in which the television signals and noise components of the NTSC system and the band compression transmission system shown in FIGS. 2 and 3 described above are superimposed.

Here, if the vertical axis is the signal level (dBm), the NTSC television signal shown by curve C in the figure is 3MH
If the signal level near Z, 4.8 MHz, and 6.8 MHz is low, and the reception condition is good and there is little noise, the signal level near 4.8 MHz and 6.8 MHz will be approximately -55 dBm, which is equal to the 3 MHz above. The signal level in the vicinity is approximately -55 dBm, although the signal level may increase somewhat depending on the video content. However, if the noise components reach their maximum due to deterioration of C/N during reception, etc., these signal levels are likely to increase to approximately -45 dBm, which is the maximum value of the noise level shown by curve d in the figure. It will be done. Also, 3.58 of the color subcarrier
The signal level near MHz and around 5.73 MHz of the audio signal is high, and in particular, the signal level around 5.73 MHz is approximately -35 dBm because it is a digital audio signal. In addition, these signal levels do not fall below the maximum noise level of approximately -45 dBm even if the reception condition worsens.On the other hand, the television signal of the band compression transmission method shown by curve e in the figure varies depending on the video content. Although there is a change in the signal level of 2 to 3 dBm, it is approximately 8. up to IMHz
The signal level is approximately -35dB.
m.

As mentioned above, there is a large difference or characteristic in the signal level between the band compression transmission method 27 NTSC system, and the difference or characteristic is best found in the frequency region indicated by A-F in Figure 4. There is.

That is, frequency region A around 3MHz and 4.8MHz
Frequency region B around z, frequency region C around 6.8 MHz, and frequency region R around 9.5 MHz,
Frequency region E around 5.73MHz and 3.58Ml1
This is the frequency region F near z.

Therefore, by comparing the above frequency regions A-F in a predetermined combination, it is possible to distinguish between a band compression transmission system and an NTSC system television signal. For example, to detect an NTSC system television signal, ,
It is sufficient to extract each signal component in frequency domain B or C and frequency domain E, compare the levels, and detect that the level in frequency domain E is higher than the level in frequency domain B or C. In addition, in order to detect a television signal using a band compression transmission method, each signal component in the frequency domain B or C and the frequency range is extracted and compared in level, and the level in the frequency domain is the same as that in the frequency domain B or C. It is sufficient to detect that it is larger. Note that for both the NTSC system and the band compression transmission system, either frequency domain B or C may be extracted, but it is appropriate to select frequency domain B. This is because, in the case of a television signal using a band compression transmission method, the signal level changes less depending on the video content in frequency domain B. In addition, in the case of an NTSC television signal, for frequency region B around 4.8 MHz, N
Since this is the frequency band in which the audio components of TSC system terrestrial broadcasting are located, the video signal level is kept low, and the audio components of satellite broadcasting are located in the above frequency range, so the frequency band B is This is because the television signal level is low regardless of the video content. Note that combinations other than the frequency domain combinations as in the above example may be used.

In addition, this discrimination method not only distinguishes between the NTSC method and the band compression transmission method, but also distinguishes between the unmanned television signal and N
It is also possible to discriminate between television signals using the TSC system or the band compression transmission system. That is, the frequency domain A mentioned above
By appropriately combining -F, it becomes possible to clearly detect the difference in level between the television signal and the unmanned state.

Hereinafter, a television signal processing apparatus according to the present embodiment will be described, which detects the difference in the frequency distribution described above and determines the format of the television signal.

In Figure 1, satellite broadcast radio waves (approximately 12
GHz) is received by an SHF band receiving antenna l such as a parabolic antenna, and supplied to a tuner circuit 2 serving as a satellite broadcast receiving circuit. In the tuner circuit 2, the above? ! Performs various processing such as tuning and detection of 7-star broadcasting waves, and connects the satellite broadcasting input terminal 11 of the television signal processing circuit 3.
is transmitted as a detected output signal.

The detection output signal input to the satellite broadcasting input terminal 11 is
Detection circuit 1 which is a detection means for detecting differences in frequency distribution
2 and a reciprocating processing circuit 13 that performs reproduction processing of the television signal. 9. is a BPF (band pass filter) 22 whose passband is around 4.8 MHz;
5. BPF23 whose passband is around 5 MHz;
Each signal is input to a BPF 24 whose passband is around 7 MHz. The BPFs 22 and 23.24 extract each component of the frequency domain B (near 4,8 MIIz), frequency domain D (near 9,5 MHz), and frequency domain E (near 5,7 MHz) from the detected output signal, respectively. Extracted. Each frequency component of the extracted detection output signal is rectified by an envelope detector 25, 26, 27, and then transmitted to a comparator 28, 29 that compares the DC voltage (l! (signal level)) of the signal. The above comparator 2
The comparator 29 outputs a detection signal indicating that the television signal is an NTSC television signal, and the comparator 29 outputs a detection signal indicating a television signal of the band compression transmission system. Compare the signal level, that is, the DC voltage value, in the frequency range E and the signal level in the frequency range E, and as mentioned above, if the signal level in the frequency range E is higher than the signal level in the frequency range B, the human-powered television signal is N.
A detection signal indicating that the TSC system is used is output; otherwise, the detection signal of the comparator 28 is not output. Further, in the above comparison 2S29, frequency domain B and frequency domain RI are compared, and if the signal level of frequency domain B is higher than the signal level of the frequency domain signal, it is detected that the input television signal is of the band compression transmission method. If the signal is not output, the detection signal of the comparator 29 is not output. In addition, the above frequency region B and frequency head region E
The level difference of the above-mentioned NTSC television signal (detected output signal) is usually about 20 dBm, but even when the C/N becomes the worst due to changes in reception conditions, the level difference of the detected output signal will be Similarly, the level difference of the detected output signal is 10 dB in the television signal of the band compression transmission method in the frequency domain B and the frequency domain.
It never goes below m.

Here, the comparator 28.29 is required to have a performance capable of detecting a difference in signal level of about 5 dBm to 6 dBm of the detected output signal, and if the comparator 28.29 does not meet this performance, the comparator 28. 29, it is possible to detect television signals of the NTSC system and band compression transmission system even under the worst reception conditions.

The detection signals detected in comparisons 2i28 and 29 as described above are transmitted to the reproduction processing circuit 13 via the output terminals 30a and 30b, respectively. The reproduction processing circuit 13 reproduces the detected output signal from the tuner circuit 2 based on the detection signal, converts it into RG and B signals, and outputs them from an output terminal 14 to a television receiver or the like.

Although the discrimination method described in the above embodiments is for responding to changes in the broadcasting method of the satellite broadcast radio waves received by the SHFHF receiving antenna, the present invention is not limited to this, and the present invention is not limited to this, but may be applied to the above-mentioned NTSC method or The invention can also be applied to discrimination processing of television signals when television signals using a band compression transmission method are manually switched to the same terminal using switching means such as a selector.

FIG. 5 shows the frequency distributions of the NTSC system and the band compression transmission system, which are switched and input to the same terminal, for example, an external input terminal, etc., using a selector, as described above.

In FIG. 5, in the band compression transmission method shown by curve r in the figure, approximately 8. There is a similar frequency distribution up to 1 MHz, but since there is no 4-phase PSK audio signal for satellite broadcasting in the NTSC system in the above case, the frequency distribution as shown by curve g in Figure 4 is 5.7 M
+l There is no audio component near z. therefore,
Here, in order to detect the NTSC method, approximately 100 K
[(Z's frequency domain G is newly set, and the frequency domain B (4, 8 MHz) and frequency domain D (9, 8 MHz) described above are
MHz), and by combining and comparing
Distinguish between SC system and band compression transmission system television signals. Here, the above frequency domain G is the synchronization signal frequency component of the NTSC system television signal, which always has a predetermined signal level regardless of the video content. It is. In addition, in the case of the terrestrial broadcasting NTSC system, the audio signal is arranged in the frequency region B around 4.8 MHz, but in the case of external input, the audio signal is input in a separate system, so the audio signal is placed in the frequency region B around 4.8 MHz. The signal level is kept low.

That is, for example, to detect an externally input television signal of the NTSC system, frequency domain B and frequency domain G are extracted, their levels are compared, and it is detected whether the level of frequency domain G is higher than the level of frequency domain B. Just do it. In addition, to detect a television signal using a band compression transmission method, it is necessary to extract frequency domain B and frequency domain 2, compare their levels, and detect whether the level of frequency domain 2 is higher than the level of frequency domain B. good. In this case as well, many combinations of frequency domains other than the above-mentioned combinations are conceivable, and it is also possible to distinguish between noise components and television signals of the NTSC system or band compression transmission system.

In addition, when receiving a television signal as a satellite broadcast radio wave as in the above-mentioned embodiment, in the above frequency range G, if the radio wave condition of the satellite broadcast deteriorates, the C/N deteriorates. The signal level is the maximum noise level (-4
5d Bm) and become approximately the same level. That is, it becomes difficult to distinguish between signals and noise, and the frequency region G cannot be used to determine the image transmission method. On the other hand, when a television signal is directly input to an external input terminal etc. as in this embodiment, the frequency range G
Since the level difference always exists at 15 dBm or more, it can be used to determine the above-mentioned image transmission method.

Next, an example of a television signal processing device that processes television signals input from the above-mentioned external input terminal etc. will be described in the sixth section.
In FIG. 6, which is explained using the block circuit diagram shown in the figure, the external input terminal 15 of the television signal processing device 3 has a fifth
A television signal of the NTSC standard system or the band compression transmission system as shown in the figure is input. The television signal input to the external input terminal 15 is transmitted to a reproduction processing circuit 13 that reproduces the television signal and a detection circuit 12 that determines the transmission method of the television signal. Here, each television signal transmitted to the input terminal 21 of the detection circuit 12 has a frequency of 100 KHz.
LPF (tel-bus filter) with the following passband
The signal is transmitted to the BPF 22, which has a pass band around 31 and 4.8 MHz, and the BPF 23, which has a pass band around 9.8 MHz. .8
Television signal components near M H2 are extracted.

The extracted television signal components are input to envelope detectors 32, 25, and 26, respectively, and rectified.
Sent to comparator 33.29. This comparison'r&33.2
At step 9, the DC voltage values of the television signal components extracted in the same manner as described above are compared and detection processing is performed. That is, the output signal of the envelope detector 32 (frequency domain G) and the output signal of the envelope detector 25 (frequency domain B) are
The signals are input to the comparator 33 and compared, and if the level of frequency domain G is higher than the level of frequency domain B, an NTSC detection signal is output. In addition, the output signal of the envelope detector 25 and the output signal of the envelope detector 2G (
The frequency 6R range D) is compared manually by the comparator 29, and if the level of the frequency range B is higher than the level of the frequency range B, a detection signal of the band compression transmission method is output.

NTS detected by comparator 33.29 as described above
The detection signal of the C system or the band compression transmission system is transmitted to the reproduction processing circuit 3 via the output terminals 30a and 30b, respectively, as described above.

In addition to the above, a case may also be considered in which both satellite broadcasting input and external input are used. The television signal processing device in this case has a configuration as shown in FIG.

That is, in the television signal processing device 4 shown in FIG. 7, the satellite broadcast radio waves transmitted through the SHFHF receiving antenna 1 are input to the satellite broadcast input terminal 1G, and are input from the terminal 16 to the SHF tuner circuit 17. Further, a television signal is also input to the external input terminal 15. here,
The television signal from the S J (F tuner circuit 17 and the external input terminal 15) is transmitted to the reproduction processing circuit 13 that performs reproduction processing of the television signal, and at the same time, the S H
The signal is transmitted to a changeover switch 18 that selectively switches and connects the output signal of the F tuner circuit 17 and the human input signal of the external input terminal 15. The changeover switch 18 operates in conjunction with, for example, an operation switch on the front panel of the television signal processing device, or is operated by a remote control or the like. The television signal selected by the changeover switch 18 is input to the detection circuit 12,
This detection circuit 12 performs the process of determining the transmission method of the television signal in the same manner as described above. That is, the detection circuit 1
2 includes an LPF 31 whose pass frequency band is 100 KHz or less, a BPF 22 whose pass frequency band is around 4.8 MHz, and 5.
The signals are transmitted to envelope detectors 32, 25, and 27.26 via a BPF 24 around 7 MHz and a BPF 23 around 9.5 MHz, respectively, and are then transmitted in a predetermined combination to a comparator 34.29. Here, the output signal of the envelope detector 32°25.27 (i.e., frequency domain G).

The signal levels of frequency domain B1 and frequency domain E) are sent to the comparator 34 for comparison, and if the level of frequency domain G or frequency domain E is greater than the level of frequency domain B, N
A TSC television signal is detected. Specifically, for example, one of the output signals of the envelope detector 32 and 27 is connected to the comparator 3 in conjunction with the switching switch 18.
This is realized by supplying the output signal of the envelope detector 25 to one input terminal of the envelope detector 25 and the output signal of the envelope detector 25 to the other input terminal. Further, the output signals of the envelope detectors 25 and 26 (that is, the signal level in the frequency domain B1) are sent to the comparator 29 and compared, and if the level in the frequency domain B is higher than the level in the frequency domain For example, a television signal using a band compression transmission method is detected. in this way,
The configuration can be simplified by switching the system identification (automatically) in conjunction with switching between satellite broadcast reception and external input terminal.

NTS detected by comparator 34.29 as described above
The detection signal of the C method or the band compression transmission method is transmitted to the reproduction processing circuit 13 in the same manner as described above.

[Effects of the Invention] In the present invention, by focusing on the frequency distribution of a standard format television signal and a band compression transmission format television signal, and detecting the difference in frequency distribution, the format can be determined in a short time. It is possible to obtain a television signal processing device that does not require the modulation content to be accurately demodulated and can reliably discriminate even under poor C/N conditions. Further, it is possible to obtain a television signal processing device with a simple and inexpensive circuit configuration.

[Brief explanation of the drawing]

Fig. 1 is a block circuit diagram of the television signal processing device of this embodiment for satellite broadcasting, Fig. 2 is a characteristic diagram showing the frequency distribution of the television signal of the band compression transmission method, and Fig. 3 is the characteristic diagram of the television signal of the NTSC system. Characteristic diagram showing the frequency distribution of the signal, Figure 4 shows the band compression transmission method of satellite broadcasting and NTSC
A characteristic diagram showing the frequency distribution of the television signal and noise components of the system, Figure 5 shows the external input band compression transmission system and the NT
A characteristic diagram showing the frequency distribution of SC system television signals and noise components. Figure 6 is a block circuit diagram of the television signal processing device of this embodiment using external input. Figure 7 is a diagram showing the frequency distribution of SC system television signals and noise components. FIG. 8 is a block circuit diagram of a television signal processing device according to an embodiment of the present invention. FIG. 8 is a block circuit diagram of a device using a conventional discrimination method. 1... SHF reception antenna 2...
- Tuner circuit 3.4...Television signal processing device 12...
. . . Detection circuit 13 . . . Regeneration processing circuit 22.23, 24.31 ・ ・ Filter 28.29,
33.34... Comparator patent applicant Sony Corporation

Claims (1)

[Scope of Claims] A television signal processing device for discriminating between a band-compressed television signal having a substantially uniform frequency distribution within a transmission band and a standard format television signal, comprising: A television signal processing device comprising a detection means for detecting a difference in frequency distribution between a television signal and the band-compressed television signal.