JPS62189893A - Television signal receiving method and its receiver - Google Patents

Abstract

PURPOSE:To upgrade the accuracy of motion correction by inserting both brightness signal and color difference signal between frames, then extending the time of the color difference signal, and applying the motion-correction to the color difference signal. CONSTITUTION:An inter-frame-insertion processing circuit consisting of a frame memory 303 and a signal-selecting switch 300 transmits a picture signal for still part to lead wires 313 and 314. As for the color difference signal transmitted by the first color extending circuit 810, current field and one frame preceding are inter-frame-inserted. The first color motion correcting circuit 813 applies the motion correction having the same amount as that of the motion correction on a luminance signal to the one of the above-mentioned signals that is one- frame preceding, however, this is executed only when motion vectors for luminance signal supplied through a lead wire 814 are singly in the horizontal direction or the vertical direction, or they are only for odd-number picture elements or even-number lines.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for receiving television signals, and more specifically, a luminance signal and a time-compressed color difference signal are time-division multiplexed, and at least between frames. The present invention relates to a receiving method and a receiving apparatus that receive a television signal subjected to sub-Nyquist sampling processing and perform interframe interpolation using a frame memory.

Conventional technology When transmitting a wideband image signal such as a high-definition television signal, the signal bandwidth is compressed by sub-Nyquist sampling [Television Society technical report material "Satellite 1-channel transmission system for high-definition television J (
MUSE j, TEBS95-2, Vol 7,
A44) F is proposed.

This MUSE method applies an offset to the sampling phase between fields, frames, and lines, and transmits an image signal by performing processing such that the sampling phase goes around in four fields, that is, two frames. Therefore, the receiving device is equipped with a frame memory to store image signals transmitted sequentially over four fields, and combines them to restore the original high-definition television image, using the known 2:1 interlaced scanning. In television, the above-mentioned inter-frame and inter-field offset subsampling processing and signal restoration processing are used for still image portions, and line-to-line offset subsampling processing and signal restoration processing are used for moving image portions. MUSE below
A conventional example of a television receiving apparatus of this type will be described with reference to the drawings.

FIG. 2 shows an example of a receiving device related to the MUSE method, and the signal input terminal 100 has an analog MUSE
The A/D converter 200 supplies signals to a signal selection switch 300 for interframe interpolation and a video filter 400 for spatial interpolation using multiple lines within the same field. The signal selection switch 300 performs interframe interpolation by switching between the previous frame signal supplied by the frame memory 301 via the conductor 302 and the current field signal from the A/D converter 20o. is controlled by a sub-sample phase control signal etc. transmitted together with the image signal. The moving image filter 400 receives an image signal for a moving part through a conductor 401, and the signal selection switch 300 receives an image signal for a moving part through a conductor 401.
12, the image signals for the still parts are respectively supplied to a mixing circuit SOO, which uses the frame correlation 4.
A motion detection circuit 600 that detects a moving part of an image switches between an image signal for a still part and an image signal for a moving part for each pixel by a detected motion signal supplied via a conductor 601, or controls the mixing ratio. will be carried out. The interfield interpolation filter 700 to which multiple signals are supplied from the mixing circuit SOO performs interfield interpolation processing between the signal of one field before the field memory 701 and the signal of the current field. The motion of the moving part is controlled so that it is interpolated within the field.

The signal output by the interfield interpolation filter 700 is time-division multiplexed into a luminance signal and a color difference signal, and in the MUSE signal, only the color difference signal is time-compressed. Therefore,
The luminance signal is sent to the signal output terminal 7 by the D/A converter 702.
03, the color difference signal is returned to the original time axis by the time axis expansion circuit 8oo, that is, the same time axis as the luminance signal, and is sent to D/D through the line sequential decoding 801 that decodes the line sequential color difference signal into a simultaneous color difference signal. A converter 802, 80
3 are supplied with color difference signals such as Cw and CN axes, respectively, and these are sent to signal output terminals 804 and 805.

The aforementioned frame memory 301 and signal selection switch 3
In the interframe interpolation loop consisting of 00, the readout timing of the image signal of the frame memory 301 is adjusted in the horizontal direction, vertical direction, or a combination thereof by the motion vector signal for the luminance signal supplied to the control signal input terminal 1o1. The structure is configured so that the position is corrected by changing the position two-dimensionally so that the image quality does not deteriorate due to camera work such as panning.Problems to be solved by the invention In the conventional receiving device described above, the control signal input terminal 1
The motion vector signal supplied to 01 is for a luminance signal, and since this motion vector signal is a signal for position correction when interpolation is performed by the receiving device, motion correction for the luminance signal is performed well. However, when performing motion correction on the color difference signal using this motion vector signal, the same position correction processing as the luminance signal is performed in the vertical direction because the color difference signal is a line sequential signal. It cannot be used and can only be used for even line shifts. For example, if a 3-bit vertical motion vector signal is used to correct the position of the luminance signal in the range of +3 lines to 14 lines for the signal from one frame before, the position of the luminance signal is corrected by +2 lines for the color difference signal. It is possible to perform motion correction for zero lines among the 14 lines, that is, for even-numbered lines, including cases where no position correction is performed, and for odd-numbered lines, it is necessary to control so that no movement correction is performed. be.

In the horizontal direction, the time axis of the color difference signal is compressed to K, and therefore, a horizontal motion vector is used for the color difference signal to perform horizontal motion correction in the range of +77 pixels to 18 pixels for the luminance signal. In this case, + for the luminance signal
4.0. -4. Only in the case of −8 pixels, motion correction of +1, 0° −2 pixels can be performed on the color difference signal.

Motion correction for these color difference signals operates essentially the same even if the motion vector for the color difference signal is transmitted together with the image signal. Therefore, in conventional receiving devices, motion correction for color difference signals is performed perpendicularly to the color difference signal. % in direction,
In the horizontal direction, the correction range is so narrow that it cannot be effectively performed.

Means for Solving the Problems The present invention provides a method for receiving a television signal in which a luminance signal and a time-compressed color difference signal are time-division multiplexed, the television signal being subject to at least sub-Nyquist sampling processing between frames. The apparatus for receiving this television signal time-expands the time-compressed color difference signal and then performs motion correction using the motion vector signal for the luminance signal. An interframe interpolation processing circuit for processing time-division multiplexed luminance signals and color difference signals including a frame memory and a signal selection circuit, and the interframe interpolation processing. A first color expansion circuit for time-expanding the time-compressed color difference signal output by the circuit, and a color difference signal motion that effectively performs motion correction on the signal one frame before, included in the output of the first color expansion circuit. a correction circuit, a second color expansion circuit for time-expanding the color difference signal output by the frame memory, and a color signal motion detection circuit for detecting a moving portion of the color difference signal from the outputs of the first and second color expansion circuits. , a video filter that performs spatial interpolation processing on the current feed signal that is the incoming input signal, a third color expansion circuit that temporally expands the color difference signal output from this filter, and this third color expansion circuit and color signal motion correction. This television receiving apparatus includes a mixing circuit which uses signals from each of the circuits as an image input signal and a signal from the color signal motion detection circuit as a control signal.

Function: The first color expansion circuit and the second color expansion circuit described above receive the image signal for the first still part of the current field and one frame before, which are the incoming input signals output by the interframe interpolation processing circuit, and the image signal for one frame, respectively. The time-compressed color difference signals of the image signals for the second still parts of the previous and two frames before are time-expanded to a predetermined length. At the output of the second color decompression circuit, the luminance signal is removed. When the motion correction of the luminance signal is for even lines or even pixels, the first color signal motion correction circuit is configured to perform motion correction in the vertical, horizontal, or both directions with respect to the signal one frame before in the first still part image signal. The second color signal motion compensation circuit performs motion compensation using a combination of
When the motion correction for the luminance signal before the frame is for even lines or even pixels, motion correction is performed for the signals of two frames in the second still portion image signal.

The color signal motion detection circuit is the first of these. Frame correlation is used between the outputs of the second color signal motion correction circuit to detect a moving portion of the image and to send a detected motion signal for controlling the mixing circuit.

Embodiment FIG. 1 shows an embodiment of the receiving device according to the present invention, and the parts in the figure whose operation is the same as the conventional example are shown in the second embodiment.
The same numbers as those in the illustration will be used. In the figure, the interframe interpolation processing circuit composed of a frame memory 303 and a signal selection switch 300 is an A/D converter 20.
An image signal for the first still part consisting of a signal from 0 to 0, that is, a signal of the current field and a signal of one frame before is sent to the conductor 313, and a second still part consisting of signals of one frame before and two frames before. ◇The frame memory 303 is connected to the control signal input terminal 1o.
The readout time, in other words, the delay time, is changed only for the luminance signal in the image signal that is time-compressed and time-division multiplexed with the luminance signal with respect to the color difference signal supplied by the signal selection switch 300, using the motion vector signal 1 or more. and performs motion compensation. A first to which image signals for the first and second stationary portions are supplied via conductors 313 and 314.
The motion detection circuit 610 detects a motion portion using the correlation between one frame or two frames of the image regarding the luminance signal portion, and outputs the motion portion to the first mixing circuit 61 via the conductor I11!611.
It is supplied as a signal to control the mixing ratio to 0. This first mixing circuit 510 inputs the image signal for the first still part supplied via the aforementioned conductor 313 and the image signal of the current field sent out by the A/D converter 200, and performs a predetermined spatial interpolation. An image signal for moving parts supplied from the moving image filter 400 via the conductor 401 is divided into two for each pixel by a control signal from the aforementioned conductor 611.
A luminance signal is supplied to an interfield interpolation filter 710 and a field memory 711 by mixing or switching two image signals, and the restored luminance signal is sent to a signal output terminal 703 via a D/A converter 702. The color difference signals are processed by a first color expansion circuit 810 for the image signal for the first static portion from the conductor 313, and a third color expansion circuit 811 for the image signal for the moving portion from the conductor 401. Furthermore, the time axis of the image signals of the second stationary portion from the conductor 314 is expanded by the second color expansion circuit 812, and returned to the original length, that is, the same length as the luminance signal described above.

The color difference signal sent out by the first color expansion circuit 810 is obtained by interpolating the current field and the previous frame.
The color motion correction circuit 813 calculates that the motion vector signal for the luminance signal supplied via the conductor 814 for the signal one frame before the signal among these signals is independent in the horizontal direction and vertical direction, or even-numbered pixels, respectively. The same amount of motion correction as that for the luminance signal is performed only in the case of even-numbered lines. The first color motion correction circuit 813 operates at the same speed as the motion correction for the luminance signal, that is, the same data processing speed, for the color difference signal sent by the first color expansion circuit 810, and the second mixing circuit 816 and the second motion detection circuit 816, a first still portion color difference signal obtained by motion-compensating the color difference signal of one frame before is supplied. The aforementioned third color expansion circuit supplies the color difference signal for the moving part to the second mixing circuit 816 via the conductor 816, and the second color expansion circuit supplies the expanded color difference signal sent from the second motion detection circuit to the second mixing circuit 816 via the conductor 817. Based on the detected motion signal, the second mixing circuit 816 controls the mixing ratio or switching of the color difference signals for the stationary portion and the moving portion for each pixel. The motion detection circuit 816 described above includes a second color expansion circuit 8.
Similarly to the first color motion correction circuit 813, the motion of one frame before is supplied from the delay circuit 818 for the color difference signal sent by 12, that is, the signal of two frames before the signal of one frame before and the signal before two frames. A second color difference signal for a still part is supplied via a conductor 820 through a second color motion correction circuit 819 that performs motion correction using a vector signal, and the color difference signal for a second still part is supplied between one frame of the first and second color difference signals for a still part. ,2
A moving part is detected using correlation between frames. A second mixing circuit 816 supplies color difference signals whose time has been expanded and whose mixing ratio between a still part and a moving part is controlled for each pixel to an interfield interpolation filter 821 and a field memory 822, respectively, and line-sequential decoding 801. , signal output terminal 804.805 via D/A converter 802.803
The color difference signals of Cw, ON axis, etc. are sent out.

Effects of the Invention As described above, when processing a television signal in which a luminance signal and a time-compressed color difference signal are time-division multiplexed, the present invention interpolates both the luminance signal and the color difference signal between frames. After that, the time of the color difference signal is expanded, and motion compensation is performed on this expanded color difference signal, so the accuracy of horizontal motion compensation is doubled compared to the conventional method, and therefore the motion compensation is This has the effect of improving the image quality of images, especially color.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a television signal receiving apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional television signal receiving apparatus. 300... Switch, 303... Frame memory, 810, 812.811... First
．． Second. Third color expansion circuit, 813, 819...
1st. To the second color movement - correction circuit, 400 moving image filter, 816...mixing circuit.

Claims (2)

[Claims] (1) A method for receiving a television signal in which a luminance signal and a time-compressed color difference signal are time-division multiplexed, the television signal being subjected to at least sub-Nyquist sampling processing between frames, and a luminance signal The apparatus for receiving the television signal time-expands the time-compressed color difference signal, and then performs motion correction using the motion vector signal for the luminance signal. Method. (2) An interframe interpolation processing circuit for processing time-division multiplexed luminance signals and color difference signals including a frame memory and a signal selection circuit, and a time-compressed color difference output from this interframe interpolation processing circuit. A first color expansion circuit for time-expanding a signal, a color difference signal motion correction circuit for effectively performing motion correction on a signal one frame before, which is included in the output of the first color expansion circuit, and a frame memory output. a second color expansion circuit for time-expanding the color difference signal; a color signal motion detection circuit for detecting a moving portion of the color difference signal from the outputs of the first and second color expansion circuits; A video filter that performs spatial interpolation processing on field signals, a third color expansion circuit that temporally expands the color difference signal output from this filter, and signals from each of the third color expansion circuit and color signal motion correction circuit. A television signal receiving device comprising a mixing circuit that uses a signal from the color signal motion detection circuit as a control signal as an image input signal.