JP2623335B2 - Television signal receiving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a so-called MUSE (Multiple Sub-nyquist Sa).
More particularly, the present invention relates to a device for converting a band-compressed television signal into a three-primary-color signal that has not been subjected to band-compression processing such as the NTSC system.

[Prior Art] The baseband bandwidth of a high definition television signal is about 30
[MHz], which cannot be transmitted over one channel of the current satellite broadcast, and therefore needs to be transmitted after being band-compressed to about 8 [MHZ]. One of systems for transmitting a high-definition television signal by compressing a band is a so-called MUSE system. The MUSE method uses a band compression method as exemplified below.

(1) The time axis of the chrominance signal is compressed to 1/4 and multiplexed in a period in the horizontal blanking of the luminance signal.

(2) In a still region of an image, dot interlace by offset sampling between fields and between frames is used.

(3) In the moving area of the image, dot interlace by offset between lines is used.

(4) Deterioration of resolution during pan and tilt is kept to a minimum by motion compensation.

Therefore, in the receiving apparatus, a band extension configuration corresponding to these band compression methods is required.

[Problems to be Solved by the Invention] However, the band-compressed television signal is NT
When compared with a standard television signal that has not been subjected to band compression as represented by the SC system, the signal and display format are different, so it is not possible to reproduce using the conventional TV receiver that conforms to the NTSC system etc. as it is Can not. Further, a conventional video cassette recorder conforming to the NTSC system or the like cannot be used as it is for recording a band-compressed television signal. Therefore, it is necessary to convert the signal using a dedicated display or a dedicated video cassette recorder.

Means for Solving the Problems The present invention has solved the above-mentioned problems, and a first invention compresses a time axis of a chrominance signal at a predetermined compression ratio and multiplexes the time axis of a luminance signal at a predetermined time. A decoding process of receiving a band-compressed television signal using dot interlacing with different offsets in a still region and a moving region of an image, and dividing the band-compressed television signal into a still region and a moving region; Means, extracting only the decoding processing output related to the moving area from the decoding processing output of the decoding processing means, converting the decoding processing output into the time axis of the standard television signal, and weighting and adding the luminance signal portions of a plurality of scanning lines. Time-axis scan conversion means for synthesizing into one scanning line and outputting as a luminance signal of a standard television signal; and obtaining the time-axis conversion from the time-axis conversion means. And a time axis extending means for supplying a standard television signal supplied thereto, time-expanding the multiplexed portion of the color signals at a ratio opposite to the compression ratio, and outputting the color signal of the standard television signal. It is a feature.

The present invention also provides a method of compressing the time axis of a color signal with a predetermined compression ratio, multiplexing the time axis of a luminance signal in a predetermined period, and performing band compression using dot interlace with different offsets in a still region and a moving region of an image. Decoding means for receiving the decoded television signal and decoding the charged compressed television signal by dividing it into a still area and a moving area, and extracting only the decoding processing output related to the moving area from the decoding processing outputs of the decoding processing means Then, the time axis is converted to the time axis of the standard television signal, the luminance signal portions of a plurality of scanning lines are weighted and added to be combined into one scanning line, and output as the luminance signal of the standard television signal. Scanning conversion means, supplied with a standard television signal obtained by the time axis conversion from the time axis conversion means, and A time axis extending means for extending the time in inverse proportion to the contraction ratio and outputting it as a color signal of a standard television signal; a luminance signal output from the time axis scan converting means and a color output from the time axis extending means A signal and a luminance signal and a chrominance signal included in the band-compressed television signal, and a switching circuit for selectively selecting and outputting one of the luminance signal and the chrominance signal of one of these four types of signals; And a dematrix means for decomposing the luminance signal and the chrominance signal selected and output by the switching circuit into three primary color signals and outputting the three primary color signals.

[Operation] According to the first aspect of the invention, the time axis of the color signal is compressed with a predetermined compression ratio, multiplexed in a predetermined period of the luminance signal, and dot interlace due to different offsets between a still area and a moving area of an image is performed. After receiving the band-compressed television signal and decoding it by dividing it into a still area and a moving area, only the decoding processing output relating to the moving area is extracted and converted to the time axis of the standard television signal. By weighting and adding the luminance signal portions of the two scanning lines and combining them into one scanning line, the luminance signal portion is output as a luminance signal of a standard television signal, and the standard television signal obtained by the time axis conversion is output. The multiplexed portion of the color signal is time-expanded at the inverse ratio of the compression ratio and output as a color signal of the standard television signal, so that the band-compressed television signal is output. A standard television signal is reproduced by interpolating information on a moving region from among abundant video information of the television signal. By doing so, the memory capacity can be reduced and the scale of hardware can be reduced.

According to the second invention, as in the first invention,
A luminance signal is output by the time axis scan conversion means, and a time signal is extended by the time axis expansion means to output a color signal. The luminance signal, the color signal, and the luminance included in the band-compressed television signal are output. The signal and the chrominance signal are arbitrarily selected by the switching circuit, and any one of the luminance signal and the chrominance signal is decomposed by the de-matrix circuit to output the three primary color signals which have not been subjected to the band compression processing.

[Embodiment] Hereinafter, an embodiment in which the present invention is applied to a receiving apparatus that converts a band-compressed television signal of the MUSE system into a three-primary-color television signal of the NTSC system will be described in detail with reference to the drawings. 1 and 2 are block diagrams showing an embodiment of a band-compressed television signal receiving apparatus according to the first invention, respectively. FIG. 3 is a detailed block diagram of the time-axis scan conversion circuit shown in FIG. FIG. 4 is a time chart showing a MUSE signal, and FIG.
FIG. 3 is a diagram schematically illustrating conversion of a scanning line with an NTSC television signal.

A satellite broadcast radio wave captured by a parabolic antenna (not shown) is demodulated to a pace band of about 8 [MHz] by a satellite broadcast (BS) tuner section (not shown), and converted into a first MUSE television signal. It is input to the receiving device shown in the figure. The input television signal is applied to an analog / digital conversion circuit 1, converted into digital data, and then applied to a clock recovery circuit 2 and a de-emphasis circuit 4. The de-emphasis circuit 4 performs an inverse process of the process by the emphasis circuit of the transmission system, and supplies the de-emphasized signal to the inter-frame interpolation circuit 5.
Since the SE method is a sample value transmission, the decoder needs to reproduce an accurate resample clock. The clock recovery circuit 2 and the timing generation circuit 3 are provided for this purpose, and thereby, an accurate resample clock can be obtained.

The frame interpolating circuit 5 includes a frame memory 6 because the static area of the received television signal is dot-interlaced by inter-frame offset sampling.
Is used to interpolate the data for the previous frame as data for dots that have been compressed and have no data. At this time,
Based on a motion vector signal provided from a control signal detection circuit (not shown), data of one frame before is moved in a predetermined direction and interpolated so as to prevent the resolution of a panned or tilted screen from deteriorating. At the same time, the frame memory 6
To perform noise reduction processing.

The television signal output from the frame interpolating circuit 5 is supplied to a low-pass filter circuit 7 to limit the band, the sampling frequency is converted by a sampling frequency converting circuit 8, and the next field interpolating circuit 9 Is prevented from occurring, and is supplied to the inter-field interpolation circuit 9 as information on the still area. The inter-field interpolation circuit 9 uses the field memory 10 to interpolate data for a dot having no data with data one field before. At this time, the field memory is controlled according to the motion vector signal given from the control signal detection circuit.
Address control is performed on the address 10, and the data position is corrected in the horizontal direction, and a panned screen is also treated as a still area to prevent deterioration in resolution. The television signal interpolated between the fields is supplied to the adaptive mixing circuit 11.

The television signal interpolated by the above-described inter-frame interpolation circuit 5 is supplied to a field interpolation circuit 13 via a sub-sample switch circuit 12. The sub-sample switch circuit 12 opens at the data timing of the interpolated dot, replaces the dot data with "0", closes the dot data with data from the beginning, and It is passed as data. The field interpolation circuit 13 has a memory for several lines, and forms data of a dot of interest (a dot to be processed) from data of several dots adjacent in the vertical and horizontal directions.

The television signal interpolated in the field is provided to the noise coring 14. The noise coring 14 removes, as a noise component, a component having a frequency equal to or higher than a predetermined frequency and a level equal to or lower than a predetermined value, and supplies the television signal from which the noise has been removed to the adaptive mixing circuit 11 described above. Adaptive mixing circuit 11
Is provided with a motion detection signal from a motion detection circuit (not shown), and has a ratio corresponding to the motion detection signal.
The television signal mixed with the television signal interpolated in each of the stationary region and the moving region is mixed, and the mixed television signal is supplied to the low-frequency replacement circuit 15.

The low-frequency replacement circuit 15 is supplied with a television signal from the de-emphasis circuit 4. The low-pass replacement circuit 15
4 of the television signal given from the adaptive mixing circuit 11
The component below [MHz] is replaced with a component below 4 [MHz] of the television signal given from the de-emphasis circuit 4, and the replaced television signal is given to the temporal filter circuit 16. The temporal filter circuit 16 uses the frame memory 17 to perform processing to reduce a change in resolution at a change point between the still area and the moving area. The television signal from the temporal filter circuit 16 is applied to a dematrix circuit 19.

The television signal output from the above-described frame interpolation circuit 5 is supplied to a time axis expansion circuit 20. The time base expansion circuit 20 extracts the color signal that has been inserted by being compressed to 1/4 during the horizontal blanking period, expands the color signal by four times in the time axis, and supplies the expanded signal to the inter-field interpolation circuit 21. The field interpolation circuit 21 uses the field memory 22 to
A dot without data is interpolated in the data one field before so as to correspond to the inter-field dot interlace for the still area. The color signal interpolated between the fields is supplied to the adaptive mixing circuit 23.

In addition, the television signal via the above-described noise coring 14 is provided to the time axis expansion circuit 24. The time axis extending circuit 24 has a time axis of 1/4 during the horizontal blanking period.
The color signal that has been inserted after being compressed is extracted, and the time axis of the color signal is expanded by a factor of four and applied to the field interpolation circuit 25. The field interpolation circuit 25 uses a built-in memory for several lines to interpolate the data of the dot of interest from the dot data adjacent in the vertical and horizontal directions, and sends the interpolated color signal to the adaptive mixing circuit 23. give. Adaptive mixing circuit
23 receives a motion detection signal from the motion detection circuit, mixes the motion detection signals at a ratio determined according to the motion detection signal, and supplies the mixture to a line-sequential decoding circuit 27.

The color signals according to the MUSE system have color-difference signals RY and BY inserted in a line-sequential manner, and a line-sequential decoding circuit 27 separates and extracts these color-difference signals, and a sampling frequency conversion circuit.
Give to 28. The sampling frequency conversion circuit 28 provides the sampling frequency of the incoming chrominance signal from the temporal filter circuit 16 to the dematrix circuit 19 so that the aliasing interference does not occur even in the conversion processing by the dematrix circuit 19 and is performed well. Is converted to the same sampling frequency as the sampling frequency of the luminance signal to be obtained.

The de-matrix circuit 19 converts the luminance signal supplied from the temporal filter circuit 16 and the color-difference signal supplied from the sampling frequency conversion circuit 28 into three primary color signals by de-matrix processing, and matches the gamma characteristic of a CRT (not shown). Gamma correction is performed, and each primary color signal is supplied to a corresponding digital / analog conversion circuit 29R, 29G, 29B. Each digital /
The analog conversion circuits 29R to 29B convert the primary color signals composed of digital signals into analog signals and output the analog signals to a display device (not shown).

On the other hand, the television signal of the noise coring circuit 14 is also supplied to the time axis scan conversion circuit 30 shown in FIG. The detailed block diagram of the time axis scan conversion circuit 30 is shown in FIG.
It is shown in the figure. Referring to the figure, the television signal given to the time axis scan conversion circuit 30 is
31 and a second time base conversion circuit 34. The line memory 31 delays an input signal by one horizontal scanning period in the MUSE system, and its output signal is given to a first time base conversion circuit 33 in the next stage.

Each of the first and second time axis conversion circuits 33 and 34 is constituted by a memory, and a clock based on the MUSE system is output from the timing generation circuit 32 by an output timing signal (read, ride address, write pulse, memory enable). A signal is written for each line, and a read is performed with a clock signal based on the NTSC system. As shown in FIG. 4, the writing to the time axis conversion circuits 33 and 34 is performed almost at the center of both the luminance signal and the chrominance signal with respect to the signal in the MUSE system, and in the horizontal direction of the NTSC system. Only the number of pixels corresponding to the number of pixels are extracted and output. The output signal of the first time axis conversion circuit 83 is provided to a third arithmetic averaging circuit 39 described later. This output signal is indicated by reference numeral B in FIG.

The output signal of the second time base conversion circuit 34 is supplied to a second line memory 35, a first arithmetic average circuit 36, a field switching circuit
37 and a time axis expansion circuit 41 described later. This output signal is indicated by the symbol A in FIG.

The second line memory 35 delays an input signal by one horizontal scanning period in the NTSC system and outputs the delayed signal. The delayed output signal (indicated by reference numeral C in FIG. 5) has a first phase. The averaging circuit 36 and the field switching circuit 37 are provided. The output signal A and the output signal B are shifted by one horizontal scanning period in the MUSE system, and the output signal A and the output signal B are shifted by one horizontal scanning period in the NTSC system.

The first arithmetic averaging circuit 36 outputs a relative daily average signal (A + C) / 2 of the output signal A of the second time axis conversion circuit 34 and the delay signal C of the second line memory 85, and The second arithmetic averaging circuit 38 of the stage.

For example, when the signal C is selected in the first field by the field switching circuit 37 and applied to the second arithmetic averaging circuit 38, this signal C and the output signal (A + C) / 2 of the second arithmetic averaging circuit 36 are calculated. Arithmetic average signal [C + (A + C) / 2]
/ 2 is output and supplied to the third arithmetic averaging circuit 39 at the next stage.

The input signal [C +
The arithmetic average of (A + C) / 2] / 2 = A / 4 + 3C / 4 and the signal B is calculated and output as A / 8 + B / 2 + 3C / 8. The output signal A / 8 + B / 2 + 3C / 8 of the third arithmetic averaging circuit 39 is employed as a luminance signal (indicated by the symbol D) in the NTSC system in the first field as shown in FIG. It is provided to the dematrix circuit 48.

When the signal A is selected by the field switching circuit 37 in the second field, the signal 3A / 8 + B / 8 + C / 8 is output from the third arithmetic averaging circuit 39 in the same manner as described above. It is adopted as a luminance signal in the NTSC system in the field.

The color signal output from the second time axis conversion circuit 34 is supplied to a time axis expansion circuit 41. Simultaneously, the time-base expansion circuit 41 performs the line-sequential decoding by expanding the color signal by four times in the time-axis, similarly to the time-base expansion circuits 20 and 24 described above.
Give to 42. The line-sequential decoding circuit 42 separates the color-difference signals (corresponding to BY and RY) inserted line-sequentially into the color signals, similarly to the above-described line-sequential decoding circuit 27, and demultiplexes the dematrix circuit. Give to 43.

In the dematrix circuit 43, the luminance signal Y and the color difference signals BY and RY input to the circuit 48 are subjected to dematrix processing to obtain
Converts each primary color signal to a corresponding digital /
This is given to the analog conversion circuits 44R, 44G, and 44B. Each of the digital / analog conversion circuits 44R-44B converts the signal into an analog signal and outputs it.

As described above, according to the receiving apparatus, the time axis of the chrominance signal is compressed with a predetermined compression ratio and multiplexed with the predetermined time of the luminance signal, and dot interlace due to different offsets in the still area and the moving area of the image is performed. After receiving the band-compressed television signal and decoding it by dividing it into a still area and a moving area, only the decoding processing output relating to the moving area is extracted and converted to the time axis of the standard television signal. By weighting and adding the luminance signal portions of the two scanning lines and combining them into one scanning line, the luminance signal portion is output as a luminance signal of a standard television signal, and the standard television signal obtained by the time axis conversion is output. Since the multiplexed portion of the color signal is time-expanded in the inverse ratio to the compression ratio and output as the color signal of the standard television signal, the band compression is performed. Of the abundant video information of the revision signal, only the information on the moving area can be extracted and interpolated to reproduce the standard television signal.For the still area where the high-definition image is compressed, the standard Since it is not used for reproducing a television signal, the memory capacity required for converting the band-compressed television signal to the standard television signal can be reduced, and the scale of hardware can be reduced. In addition, a display device dedicated to the MUSE band compression television signal or a display device conforming to a standard television signal format that is not subjected to charge compression processing such as the NTSC system without using a video cassette recorder. You can display images on the
It is possible to record a band-compressed television signal using a cassette recorder.

FIG. 6 is a block diagram showing an embodiment of the band compression television signal receiving apparatus according to the second invention. In this figure, the same components as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.

The device shown in FIG. 6 is different from the device shown in FIG. The switching circuit 18 includes a luminance signal and a chrominance signal output from the temporal filter 16 and the sampling frequency conversion circuit 28 according to the switching selection of the operator, the time-axis scan conversion circuit 30, and the line-sequential decoding circuit 42. Is switched between the luminance signal and the color difference signal output from the multiplexor, and are supplied to the dematrix circuit 19 in the next stage.

The dematrix coefficients used in the dematrix processing are the same as the coefficients in the MUSE system and the coefficients converted to the NTSC system. Therefore, even if the dematrix circuit 19 is shared, no problem occurs and an appropriate three primary color signal is obtained. be able to. Therefore, by introducing the switching circuit 18, the structure of the band compression television signal receiving apparatus can be simplified.

In the above embodiment, an apparatus for converting a band-compressed television signal based on the MUSE system into three primary color signals based on the NTSC system has been described in detail. The present invention is also applicable to the case of converting into a television signal.

[Effects of the Invention] As described above, according to the first invention, the time axis of the color signal is compressed at a predetermined compression ratio and multiplexed in a predetermined period of the luminance signal, and the still and moving areas of the image are Receives a band-compressed television signal using dot interlacing with different offsets, decodes it into a still area and a moving area, extracts only the decoding output for the same area, and outputs a standard television signal. By converting the luminance signal portions of a plurality of scanning lines into a single scanning line by weighting and adding them, thereby outputting as a luminance signal of a standard television and obtaining by the time axis conversion. A configuration in which the multiplexed portion of the color signals is time-expanded at an inverse ratio to the compression ratio, and the standard television signal is output as a color signal of the standard television signal. Therefore, from the abundant video information of the band-compressed television signal, only the information relating to the moving area was extracted, and this was interpolated to reproduce the standard television signal, and a high-definition image was compressed. Since the static area is not used for reproduction to a standard television signal, the memory capacity required for converting the band-compressed television signal to the standard television signal can be reduced, and the scale of the hardware can be reduced. Display according to the standard television signal format that is not subjected to band compression processing, such as NTSC, without using a dedicated display device or video cassette recorder for MUSE band compression television signals. Displaying images on a device or recording a band-compressed television signal using a video cassette recorder. Excellent effects such as kill.

According to the second invention, as in the first invention,
A luminance signal is output by the time axis scan conversion means, and a time signal is extended by the time axis expansion means to output a color signal. The luminance signal, the color signal, and the luminance included in the band-compressed television signal are output. The signal and the chrominance signal are arbitrarily selected by the switching circuit, and any one of the luminance signal and the chrominance signal is decomposed by the de-matrix circuit to output the three primary color signals which are not subjected to the band compression processing. In addition, the dematrix circuit can be used for both the band compression television signal and the standard format television signal, and the structure of the charging compression television signal receiver can be simplified.

[Brief description of the drawings]

FIGS. 1 and 2 are block diagrams each showing an embodiment of a band-compressed television signal receiving apparatus according to the first invention, and FIG. 3 is a detailed block diagram of a time-axis scan conversion circuit shown in FIG. FIG. 4, FIG. 4 is a time chart showing a MUSE signal, FIG. 5 is a diagram schematically showing conversion of scanning lines between a MUSE system television signal and an NTSC system television signal, and FIG. FIG. 6 is a block diagram showing an embodiment of a band-compressed television signal receiving apparatus according to the second invention. 18 Switching circuit 19 Dematrix circuit 20, 24, 41 Time expansion circuit 30 Time scan conversion circuit 42 Line sequential decoding circuit

Claims (2)

(57) [Claims] 1. A time axis of a chrominance signal is compressed with a predetermined compression ratio, multiplexed in a predetermined period of a luminance signal, and band-compressed using a dot interlace with a different offset between a still region and a moving region of an image. Receiving the television signal,
Decoding processing means for separating the band-compressed television signal into a still area and a moving area, and extracting only a decoding processing output related to the moving area from the decoding processing outputs of the decoding processing means, A time axis scan conversion means for exchanging for a time axis, weighting and adding the luminance signal portions of a plurality of scanning lines to synthesize one scanning line, and outputting as a luminance signal of a standard television signal; The time when the standard television signal obtained by the time axis conversion is supplied from the conversion means, and the portion where the color signals are multiplexed is time-expanded at the inverse ratio to the compression ratio and output as the color signal of the standard television signal. An apparatus for receiving a television signal, comprising: an axis extending unit. 2. A time axis of a color signal is compressed with a predetermined compression ratio, multiplexed in a predetermined period of a luminance signal, and band-compressed using a dot interlace with a different offset between a still region and a moving region of an image. Receiving the television signal,
Decoding processing means for separating the band-compressed television signal into a still area and a moving area, and extracting only a decoding processing output related to the moving area from the decoding processing outputs of the decoding processing means, A time axis scan conversion means for exchanging for a time axis, weighting and adding the luminance signal portions of a plurality of scanning lines to synthesize one scanning line, and outputting as a luminance signal of a standard television signal; The time when the standard television signal obtained by the time axis conversion is supplied from the conversion means, and the portion where the color signals are multiplexed is time-expanded at the inverse ratio to the compression ratio and output as the color signal of the standard television signal. Shaft extension means;
The luminance signal output from the time-axis scan conversion unit, the color signal output from the time-axis expansion unit, and the luminance signal and the color signal included in the band-compressed television signal are supplied. A switching circuit for arbitrarily selecting and outputting one of the luminance signal and the chrominance signal, and a dematrix means for decomposing the luminance signal and the chrominance signal selectively output by the switching circuit into three primary color signals and outputting the same; And a television signal receiving device.