JPH01212194A - High fidelity television receiver - Google Patents

Abstract

PURPOSE:To obtain a high-picture-quality frieze picture by using the normal signal of the line corresponding to an interlace from an intra-field inserting means, preparing the auxiliary signal of the line which does not correspond to the line for a luminance signal and a chrominance signal respectively and supplying them to a mixing means. CONSTITUTION:When the frieze picture is requested, a field signal, which is taken out from an inter-frame inserting part 6, having the same capacity at any time is supplied tot he intra-frame inserting means. Consequently, even when a motion part is stored in memories 9 and 11 in the inter-frame inserting part 6, a flicker is not generated. Further, since an interlace correcting circuit 19 executes an interlace-correction for the separate interlaces by the luminance signal and the chromiance signal, even when the frieze picture is set by repeatedly using the same data, the flicker due to the interlace is not generated. Thus, the high-picture-quality frieze picture can be obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a high-definition television that demodulates and reproduces a band-compressed high-definition television signal into the original wideband high-definition television signal. The present invention relates to a television receiver, and particularly relates to a decoder circuit that obtains a good image when a frozen image is obtained.

(Prior Art) As a method of compressing the bandwidth of a wideband high-definition television signal to a level that is practical for transmission, MUSE is a method of subsampling the original high-definition television signal in a cycle of four fields.
(Multiple Sub-NyQlstSample
NHK Giken Monthly Report.

(written by Ninomiya, Vol. 27, No. 7, 1982).

Figure 5 shows a band-compressed high-definition television signal (MU
This figure shows a decoder for demodulating a SE signal (referred to as SE signal) to the original wideband high-definition television signal.

The MUSE signal (2) is supplied to input terminal 1, and the MUS
The E signal (2) is input as a signal (5) to the interframe interpolation unit 6 via the switch 3, which is closed during normal demodulation. The switch 3 is turned off when a signal requesting a frozen image for freeze playback is input to the terminal 4, and prohibits input of a new MUSE signal to the interframe interpolation section 6.

The interframe interpolation unit 6 interpolates the signal one field before the input signal (5) and the signal three fields before the input signal (5) in the field memory 9 to generate the signal (10).
) is generated by interpolating the signal two fields before and the signal four fields before. Then, in the input switching circuit 7, the signal included in the signal (12) four fields before is replaced with a new input signal (5), that is, the current signal and the signal two fields before are interpolated into a signal (8 ) is processed in a cyclic manner.

The signal (8) is supplied to the intra-field interpolation unit 17 for intra-field interpolation. The intra-field interpolation unit 17 generates an intra-field interpolated signal (18) from the data of the current field and supplies it to the mixing circuit 51. The interfield interpolation section 47 uses a delay line of the intrafield interpolation section 17 to delay the signal (8) by an amount corresponding to the amount of delay in the intrafield interpolation section 17 (for example, the luminance signal is 2H, the color signal is 4H). A signal (46) with a delay of (H is one horizontal period) is input. In the interfield interpolation unit 47, the signal (46
) is used to interpolate data for four fields between fields to obtain a signal (48) and supply it to the mixing circuit 51. The motion detection unit 49 detects image motion using the signal (8),
A motion detection signal (50) is obtained. The mixing circuit 51 outputs the signals (18) and (48) at a ratio according to the motion detection signal (50).
Mix with. In the case of a moving image, the ratio of the signal (18) is large, and in the case of a still image, the ratio of the signal (48) is large.

The above decoder has a freeze function as disclosed in Japanese Utility Model Application Publication No. Sho 61-121083.

When a frozen image is requested, the freeze signal supplied to terminal 4 turns off switch 3, and a new signal (
2) is prohibited from being input to the interframe interpolation unit 6. In addition, the input switching circuit 7 stops switching the input, selects only the output signal (12) of the field memory 11, and selects only the output signal (12) of the field memory 11.
8). As a result, data for four fields in the field memories 9 and 11 are cyclically processed and held, and a high-quality television signal of a frozen image can be obtained at the output section 52.

However, in the above circuit, image data of the same field is not always output as the signal (8) during the period in which a frozen image is requested. Therefore, if there is movement in the original stored image, the frozen image will flicker at the moving parts.

(Problems to be Solved by the Invention) In the conventional MUSE decoder, when a frozen image is requested, a flicker problem may occur in a moving part of the frozen image, degrading the image quality.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a high-definition television receiver that can eliminate flicker problems and obtain high-quality frozen images.

[Configuration of the Invention (Means for Solving Problems) This invention provides the following features when a frozen image is requested:
Means are provided for inhibiting high definition television signals from being written to the interframe interpolation means having a second field memory. And as an input signal to the intra-field interpolation means that constitutes the demodulation section.

A switching means is provided for alternately inputting the output of the first field memory and the output of the second field memory for each field. Furthermore, the luminance signal and the color signal are respectively delayed and inputted to the interfield interpolation means to correspond to the amount of delay in the interfield interpolation means,
Further, using the normal signal of the line corresponding to the interlace from the field interpolation means, create auxiliary signals for the line that does not correspond to the line for the luminance signal and color signal, respectively, and combine the auxiliary signal and the normal signal. An interlace correction means is provided which selects and derives the signal for each field and supplies it to the mixing means as a final field-interpolated signal.

(Function) With the above means, when a frozen image is requested, a field signal with the same content is always extracted from the interframe interpolation section and supplied to the intraframe interpolation means.
Even if a moving part is stored in the memory of the intra-frame interpolator, no flicker occurs. In addition, interlace correction is performed for separate interlaces for the luminance signal and color signal, so even if the same data is used repeatedly to create a frozen image, it is possible to obtain a high-quality frozen image without flickering due to interlace. can.

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

FIG. 1 shows one embodiment of the present invention, in which a MUSE signal (2) supplied to an input terminal 1 is input to an interframe interpolation section 6 via a switch 3 that is on during normal operation. The interframe interpolation section 6 has an input switching circuit 7, a field memory 9, and a field memory 11 arranged in series and cyclically, and has the same configuration as that described in FIG. 5.

In this device, when the signal from the interframe interpolation section 6 is supplied to the intrafield interpolation section 17, the input side signal (8) and the output side signal (10) of the field memory 9 are selected by the selector 13. can be supplied. The intra-field interpolation unit 17 creates an intra-field interpolated signal (18) from the data of the current field and supplies it to the interlace correction circuit 19.

When a frozen image is requested, the switch 3 is turned off by the freeze signal applied to the terminal 4, and the input switching circuit 7 enters a state in which only the signal (12) from the frame memory 11 is selected. In addition, the selector 13
When a freeze signal is applied to terminal 15, signals (8) and (1) are activated in response to a field switching signal applied to terminal 15.
0) are alternately selected for each field and supplied to the intra-field interpolation unit 17. Therefore, the intra-field interpolator 17
A signal with the same content will always be tracked and introduced.

By the way, the MUSE signal (2) is an interlaced signal. Therefore, if the same signal is always selected by the selector 13, the line concerned and the line other than the concerned line become image data of the same line, and the signal (18) is no longer an interlaced signal. If this image is projected as is, line flicker for one line will occur.

Therefore, in this embodiment, the signal (18) is supplied to the interlace correction circuit 19, and the interlaced signal (38
). The interlace correction circuit 19 has an ink-lace correction system for luminance signals and an interlace correction system for color signals. The luminance signal interlace correction circuit is composed of an IH delay line 20 and an adder 22, and the adder 22 adds and averages the signal (21) and signal (18) from the IH delay line 20 to obtain a signal (23). obtain. When a frozen image is requested, the signal (23) and the previous signal (18) are switched and derived for each field by the selector 24. Note that during normal demodulation processing, the selector 24 selects and derives only the signal (18). When the freeze signal is supplied to the terminal 25, the selector 24 alternately selects and derives the signals (23) and (18) in response to the field switching signal supplied to the terminal 26, and outputs the freeze signal. is not given, only signal (18) is selected and derived.

The output signal (27) of the selector 24 is supplied to the selector 36.

On the other hand, the color signal interlace correction circuit uses the 2H delay line 2
8. Adder 30. It has a selector 32.

As shown in FIG. 4, the color signal in the MUSE signal is transmitted line-sequentially with the Cv multiplied signal CN signal, which is a color difference signal, being switched line by line.

Now, the solid lines in Fig. 4 (b, d, f.

Assume that h) is the relevant line corresponding to interlacing, and the line indicated by a broken line (a+C+''+g) is a line that is not relevant.Then, line a.

It is assumed that b, e, and f are CW multiplied signals, and c, d, g, and h are CN signals. When the image is frozen, it is sufficient to use the solid line as is in the field of the relevant line, but in the next field that does not apply, a new signal of the broken line is created from the signal of the solid line that is input again. I need to do it. At this time, for example, if you want to generate a CW multiplied signal indicated by a dotted circle in the figure, use the signals on lines b and f to generate the CW multiplied signal shown in the solid line.

Make by adding at a ratio of 1:3. Therefore, when the signal on line f is input now, it is necessary to delay the signal on line b by two line periods and then add it.

In order to perform the above processing, the color signal line correction system includes two
An H delay line 28 is provided. The selector 32 is the fourth
In the field from which the solid line in the figure is derived, the signal (18
) is adopted as is, and when deriving the signal of the broken line in FIG. 4, the signal (31) from the adder 30 obtained according to the above-mentioned principle is selected and derived. Therefore, even when the 'C1 image is frozen, the color signal (35) derived from the selector 32 becomes a signal having an interlaced relationship.
The signal is supplied to the selector 36. Note that the selector 32 is controlled to select only the signal (18) during normal playback. That is, when there is no freeze signal at the terminal 33, only the signal (18) is selected and derived, and when the freeze signal is supplied to the terminal 33, the field switching signal applied to the terminal 34 selects and derives the signal (18). (31) are alternately selected for each field and derived as a signal (35).

The selector 36 selects the signal (27) during the brightness signal period of the MUSE signal according to the timing signal applied to the terminal 37.
is selected and derived, and in the color signal period, the color signal (35) is selected and derived. In this way, the intra-field interpolation unit 17
The signal (18) from the interlace correction circuit 19 independently performs interlace correction on both the luminance signal and the color signal.
This becomes an intra-field interpolation signal (38) and is supplied to the mixing circuit 51.

Next, in this apparatus, the signal (46) supplied to the interfield interpolation section 47 is the signal (8) delayed by the delay circuit 39.

The signal (46) input to the interfield interpolation section 47 must be delayed by an amount commensurate with the signal delay of the previous field interpolation section 17. Conventionally, for this purpose, a delay line included in the intra-field interpolation section 17 ensures a delay of, for example, the luminance signal 2H1 and the color signal 4H. However, in this embodiment, since each field signal input to the intra-field interpolation unit 17 during image freezing is a signal interpolated between the same frames, the delay line in the intra-field interpolation unit 17 is If the output is used as an input to the interfield interpolation unit 47, normal interfield interpolation cannot be obtained.

Therefore, in this embodiment, in order to obtain a signal (46) corresponding to the amount of delay of the intrafield interpolation section 17 and supply it to the interfield interpolation section 47, the 2H delay line 40° and the 4H delay line 42. A signal (46) is obtained by a delay circuit 39 using a selector 44. The selector 44 is controlled by a timing signal applied to a terminal 45, and selects and derives the output signal (41) of the 2H delay line 40 during the luminance signal period.
In the color signal period, the output signal (43) of the 4H delay line 42 is selected and derived. The signal (46) is subjected to interfield interpolation processing in the interfield interpolation unit 47, and the signal (48) is
and is supplied to the mixing circuit 51.

The mixing circuit 51 controls and mixes the signals (38) and (48) in accordance with the motion detection signal (50), and outputs a high-quality video signal to the output terminal 52. The motion signal is detected by the motion detection section 49 using signal (8).

FIG. 2(a) shows another embodiment of the interlace correction circuit 19, and FIG. 2(b) shows another embodiment of the delay circuit 39. When performing interlace correction, the MUSE signal can be divided into a luminance signal period and a color signal period, so IH
The delay lines 53 and 54 are connected in series, and the IH delay line 53 is connected in series.
This is used for both luminance signal line correction and color signal line correction. That is, the configuration is such that the IH delay signal (21) and the signal (18) are supplied to the adder 22, and the output signal of the 2H delay line 54 and the signal (18) are supplied to the adder 30. With this configuration, the line correction signal of the luminance signal when a frozen image is requested is sent to the adder 2.
2, and the line correction signal of the color signal is obtained from the adder 30. Selectors 24, 32, 36 are controlled in the same manner as in the previous embodiment.

FIG. 3B shows another embodiment of the delay circuit 39.

This example connects 2H delay lines 55 and 56 in series to
It is configured to supply the output signal (41) of the H delay line 55 and the output signal (4B) of the 2H delay line 56 (a signal obtained by delaying the signal (8) by 4H) to the selector 44. selector 4
4 is controlled to select the signal (41) during the luminance signal period and select the signal (43) during the color signal period, as in the previous embodiment.

FIG. 3 shows still another embodiment of the interlace correction circuit 35.

In this embodiment, IH delay lines 53 and 55 are connected in series,
The output (21) of the IH delay line 53 and the signal (18) are added by an adder 22, and the output of the adder 22 is supplied to one of the selectors 55. The selector 55 receives the timing signal at the terminal 55, selects and derives the signal (23) during the luminance signal period, and supplies the selected signal (23) to the selector 58 as the signal (57).

When a frozen image is requested, the selector 58 selects
The signal (57) and signal (18) are alternately selected and derived for each field by a field switching signal supplied to the terminal 60, and an interlace-corrected luminance signal is derived. Further, in the color signal period, the output signal (29) of the IH delay line 54 and the signal (18) are added by the adder 30, and the added signal (31) is supplied to the other input of the selector 55. During the color signal period, the selector 55 is controlled by the timing signal to select and derive the signal (31).

Therefore, the output signal (57) of the selector 55 becomes an interlace correction signal of the color signal, and is supplied to the selector 58. When a freeze image is requested, this selector 58 sends a signal (5
7) and the signal (18) are alternately selected and derived to output an interlaced signal (38).

[Effects of the Invention] As explained above, the present invention makes it possible to obtain a high-definition television receiver that can eliminate flicker problems and obtain high-quality frozen images even when frozen images are requested. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2(a) is a diagram showing another embodiment of the interlace correction circuit of FIG. 1, and FIG. FIG. 3 is a diagram showing another embodiment of the interlace correction circuit, FIG. 4 is a diagram for explaining the principle of interlace correction regarding color signals, and FIG. 5 is a diagram showing another embodiment of the interlace correction circuit. FIG. 1 is a block diagram showing a conventional MUSE decoder. 3...MUSE signal, 6...Interframe interpolation unit, 7
...Input switching circuit, 9.11...Field memory, 13, 24, 32, 36.44...Selector, 1
7... Intra-field interpolation unit, 1... Interlace correction circuit, 20.53.54... IH delay line, 28
．． 40,55.56...2H delay line, 22°30...
Adder, 42... 4H delay line, 47... Interfield interpolation section, 49... Motion detection section, 51... Mixing circuit. Applicant’s representative Patent attorney Takehiko Suzue a Cw−−−−−−m−−−−−−−−−−
-------------g CN----1------
~---------------m---h C
N □ Figure 4

Claims (1)

[Claims] A high-definition television signal that is interlaced and band-compressed by subsamples that circulate in n fields, and whose color signals are line-sequential is input, and n/2 fields of this high-definition television signal are input. an interframe interpolation means having first and second field memories stored in series and performing interframe interpolation processing by circulating signals in the first and second field memories; inter-field interpolation means for performing inter-field interpolation processing on the high-definition television signal output from the inter-field interpolation means; and inter-field interpolation processing for the high-definition television signal from the inter-field interpolation means. intra-field interpolation means; motion detection means for obtaining an image motion detection signal using the high-definition television signal from the interframe interpolation means; In a decoder circuit comprising mixing means for mixing the output of the interpolation means and the output of the intrafield interpolation means, when a frozen image is requested, a new high-definition television signal is sent to said field memory. and means for inhibiting the output of the first field memory and the output of the second field memory from being written as input signals to the field interpolation means when the frozen image is requested. switching means for inputting the signal alternately for each field; and when the frozen image is requested, the signal input to the interfield interpolation means is changed to a luminance signal so as to correspond to the amount of delay in the intrafield interpolation means. and a delay means for delaying and inputting the auxiliary signal of the line not corresponding to the line using the normal signal of the line corresponding to the interlace from the field interpolation means and inputting the luminance signal and color signal, respectively. 1. A high-definition television receiver comprising interlace correction means for selectively switching and deriving the auxiliary signal and the regular signal for each field and supplying the auxiliary signal and the regular signal to the mixing means.