JPH03240394A - Muse decoder - Google Patents

Abstract

PURPOSE:To correct discontinuous movement of 2-3 system of MUSE signals by generating a smoothed vector signal from a moving vector signal at a smoothing means and delaying the MUSE signal inputted to an inter-frame interpolation circuit based on the vector signal. CONSTITUTION:When a MUSE signal subjected to telesine-conversion is inputted, a separation circuit 3' detects a flag and outputs a telesine-discrimination signal FV to turn switches SW1, SW2 from the position (a) into the position (b). A smoothing circuit 22 outputs a smoothing vector signal to a variable delay circuit 20 to apply variable control to a delay time of the MUSE signal and the pattern is deviated in horizontal and vertical directions to correct the continuity of the pattern. A one frame MUSE pattern and the MUSE pattern of a current field are subject to inter-frame interpolation by an inter-frame interpolation circuit 7. In this case, in order to correct the pattern due to panning or the like, the moving vector signal is used. In this case, the MUSE signal of a current field is delayed by the circuit 20, then the moving vector signal is corrected in matching therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention is directed to a video signal of the MUSE method (MUSE signal) when a high-definition television signal converted to telecine is transmitted by the MUSE method. MUSE to demodulate
Regarding decoders.

(b) Conventional technology When converting film video to high-definition video (high-definition video format developed by NHK), the "2-3 system" and "
A motion-compensated method is being considered.

In other words, as shown in Figure j1!2, film has a rate of 24 frames per second, and high-definition has a rate of 60 fields (30 frames) per second. For this reason, in the "2-3 method", among two adjacent frames, one frame is converted into 2 fields and the other frame is converted into 3 fields. However, with this method,
Unnatural motion (shudder) occurs because the same film frame is repeated two or three times.

Therefore, telecine conversion using a "motion compensation type" method uses a motion vector signal to move the image position in the horizontal and vertical directions and perform motion compensation to smooth the motion of the image.

Regarding the "2-3 method" telecine, for example, "
NH titled ``35-Laser Telecine for HDTV''
It is described in the K Giken Monthly Report (October 1985 issue).

On the other hand, a MUSE method is known in which a high-definition video signal (high-definition signal) is band-compressed using a multiple sub-Nyquist sampling encoding method.

The MUSE method is known by Bunyu et al. below.

(a) 112-11 of the magazine “Nikkei Electronics, March 12, 1984 issue” published by Nikkei McGraw-Hill.
6 pages.

(b) rN) IK Giken Monthly Report, July 1984 issue, pages 275-286, ``New Transmission Method for High-Definition Television''
.

(c) Pages 19 to 24 of the magazine "Television Technology September 1984 Issue" published by Denshi Gijutsu Publishing Co., Ltd.

(d) Magazine “Radio Science 19” published by Japan Broadcasting Publishing Association
April 1984 issue, pages 103-108.

(e) rNHK Technical Research, published in 1987, No. 39
rMU, pages 18-53 of "Vol. 2, No. 172"
Development of SE method”.

(f) “Nikkei Electronics, November 2, 1987
"Transmission method for high-definition broadcasting using satellites MUSEJ" on pages 189-212 of "Japanese Edition".

A video signal band-compressed by the MUSE method is divided into a moving image signal and a still signal in its decoding process. In the conventional MUSE decoder, in static processing, the video signal is processed by performing inter-field interpolation processing and inter-frame interpolation processing using signals for a total of 4 fields: the currently input signal and the previous 3 fields. Decryption is performed.

On the other hand, in motion-based processing, since there is generally no correlation with the previous field, the signal is decoded by performing intra-field interpolation processing using only the currently input signal.

FIG. 3 is a block diagram of a MUSE decoder which is the background of the present invention. This MUSE decoder is connected to receive a video signal (hereinafter referred to as a MUSE signal) SO whose band has been compressed by a multiple sub-Nyquist sampling encoding method.

MtJSE signal So (see FIG. 4) is applied to a low-pass filter (1). The signal from which noise has been removed by the filter (1) is A/D converted by the A/D converter (2). The A/D converted signal is separated into a synchronization signal and a control signal (see FIG. 5) by a circuit (3). The A/D converted signal is sent to a moving part detection circuit (6
), an interframe interpolation circuit (7), an interfield interpolation circuit (9), and an intrafield interpolation circuit (10), respectively. The moving part detection circuit (6) detects stationary and moving signals in response to the motion vector output from the synchronization/control signal separation circuit (3).

In stationary signal processing, interframe interpolation processing is performed by the circuit (7), and the output signal (Sl)
Inter-field interpolation processing is performed by circuit (8) for each field. The signal (S2) subjected to interfield interpolation processing is given to a mixing circuit (11). Mixed circuit (11)
Now, the intra-field interpolated signal (S4) is combined with the stationary signal (S2).

The signal mixed by the mixing circuit (11) is decoded by the TCI decoder (12). The decoded signals are sent to a D/A converter (13
) after 1) D/A conversion by low pass filter (1)
4), a high-definition signal is obtained.

(c) Problems to be Solved by the Invention The present invention solves the problem of telecine MU converted by the "2-3 method".
When the SE signal is demodulated, the motion becomes discontinuous as described above. If the transmitting side uses the "motion compensation type method" using motion vectors as described above, this will not result in discontinuity, but if the transmitting side transmits the "2-3 method" MUSE signal There is also.

An object of the present invention is to provide a MUSE decoder that corrects motion discontinuity of a "2-3 system" MUSE signal.

(d) Means for Solving the Problems The present invention provides a MUSE decoder that detects a motion vector signal multiplexed on a MUSE signal and performs motion vector correction in an interframe interpolation circuit (7). In order to smooth the motion vector, smoothing means (22) inputs the motion vector signal and outputs a smoothed vector signal, and the smoothed vector signal from the smoothing means (22) is used to smooth the difference between the frames. Interpolation circuit (7)
and a motion vector correction means (24) for creating a corrected motion vector signal from the motion vector signal and the smoothed vector signal. Features.

(e) Effect In the present invention, the value of the motion vector signal is smoothed by the smoothing means (22
) and input to the interframe interpolation circuit (7)
A smoothed vector signal is created to reduce the screen vector movement of the USE signal, and based on this smoothed vector signal, the MUSE signal input to the interframe interpolation circuit is delayed by the variable delay means (20). let

(F) Embodiment First, the flag (fg) included in the control signal of the MUSE signal of this embodiment will be explained with reference to FIGS. This flag can be used, for example, in the reserve area (2) in Figure 5.
1-32).

This figure 6 shows the flag (f) included in the MUSE signal sO.
FIG. 7 is a timing diagram for explaining g). In FIG. 6, the frame number of the original film and the frame number and field number of the video signal obtained by telecine are shown together with a flag (fg).

As mentioned above, film images progress at 24 frames per second, and video images progress at 30 frames (60 fields) per second. Five frames are associated. Therefore, the video fields (ao) (aE) (bo) were obtained based on frame 1 of the film. Also, field (bE) based on frame 2
(cO) is obtained. Furthermore, fields (cE) (do) (dE) are obtained based on core 3, and fields (eO) (eE) are obtained based on coma 4. From this, it can be seen that fields (ao), (aE), and (bo) are correlated with each other. Similarly, the field (
bE) and (eo), field (cE) (dO)
(dE), as well as fields (eO) and (eE
) also have a correlation in each field.

The flag included in the control signal of the MUSE signal (
fg) shows the correlation. That is, the flag (fg) is, for example, the field (aE) and (bO
) shows a high level of Therefore, it can be indicated by a flag (fg) that these fields (aE) and (bo) have a correlation with the previous one or two fields. Similarly, it can be shown that fields (cOXdo) and (dE) (eE) are correlated with one or two immediately preceding fields, respectively.

Next, referring to FIG.
3-system telecine conversion is performed and converted into a MUSE signal by a MUSE encoder, the screen at the MUSE decoder that received this MUSE signal and the motion vector signal (V) in the control signal at that time are shown. Note that the value of the motion vector signal indicates the motion vector between frames.

! Referring to FIG. II1, a schematic block diagram of an embodiment of the present invention is shown. In FIG. 1, (20) is a variable delay circuit. (22) is a smoothing circuit that outputs a smoothing vector signal for smoothing the screen based on the motion vector signal. (3') is a synchronization control signal separation circuit that detects the presence of the flag (fg) and sends a telecine discrimination signal (
FV) is output. (SWI) is a switch that is switched to the b side during telecine. (24) is a motion vector signal generation circuit for telecine, which outputs a motion vector signal for telecine based on the motion vector signal outputted to the interframe interpolation circuit (7) one frame before, the current motion vector signal, etc. (SV2) is a switch that selectively outputs a motion vector signal for telecine instead of a regular motion vector signal during telecine.

The operation will be briefly explained with reference to FIGS. 1 and 7.

First, the switch (SV11.5W2) is normally connected to the a side. Next, when the telecine-converted MUSE signal is input, the synchronization control signal separation circuit (3
') detects the flag (fg) and outputs the telecine discrimination signal (
FV) and change the switch (SWI, SV2').

The smoothing circuit (22) outputs a smoothed vector signal as shown in FIG. 7(d), which is obtained by halving the values of the motion vector signals of the first and third fields. This smoothed vector signal is input to the variable delay circuit (20), and the delay time of the MUSE signal is varied and controlled to change the screen horizontally and horizontally as shown in FIG. 7(e).
Shift vertically. In this case, the interframe interpolation circuit (
The input of the MUSE signal to 7) is accelerated, and the position of the vertical line is slightly shifted to the left. This corrects the continuity of the screen of the MUSE signal.

Next, the motion vector signal correction circuit (24) will be explained.

In other words, the variable delay circuit (20) allows the input MUS
The continuity of the screen of the E signal has been corrected. By the way, as is well known, the interframe interpolation circuit (7)
MUSE screen between frames and input IJ! The MU S E1m plane of the field is inter-frame interpolated.

At this time, a motion vector signal is used to correct the screen shift due to panning, etc., but as described above, the input MUSE signal of the current field is delayed and controlled by the variable delay circuit (20). Therefore, the motion vector signal must also be corrected accordingly. In other words,
As is clear from FIGS. 7(e) and 7(f), the corrected motion vector signal (SV) is (motion vector of current field) - ((smoothed motion vector of current field))
−(smoothed motion vector of one frame before)).

In other words, if there is a third field, S V , = V , −
(V, 5-VIS).

In the above embodiment, the telecine mode was detected using the flag (fg), but this is due to the periodicity of the motion vector signal as shown in FIG. ” The period of telecine may be determined by detecting the periodicity of “Next O”.

Further, although the motion vector in the control signal sent from the transmitting side is an inter-frame vector, the present invention is also applicable to inter-field vectors.

In this case, it is naturally necessary to make improvements to the smoothing circuit, etc.

In addition, in this embodiment, the first field of the motion vector (first field and third field) in which the same value continues twice
Since the 4th field and the 5th field are corrected, there is a drawback that the 4th field and the 5th field are the same screen, but if the cost is worth it, it is natural to correct the 1st to 4th fields to make it a continuous screen. good.

(g) Effect of the invention As described above (according to the present invention, MU by telecine conversion
M that can output continuous playback screen even if SE signal is received
A USE decoder can be realized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 2 is a diagram illustrating telecine conversion. FIG. 3 is a diagram showing a well-known MUSE decoder, FIG. 4 is a diagram showing a MUSE signal, and FIG. 5 is a diagram showing a control signal. FIG. 6 is a diagram illustrating a telecine flag. 7th
The figure is a diagram for explaining the operation of FIG. 1. (7)...Interframe interpolation circuit, (SO)...MUSE signal, (fg)...flag, (3°)...synchronous control signal separation circuit (telecine MUSE signal detection means), ( SW2)...Switch (switching means), (22)...
- Smoothing circuit (smoothing means), (20)...variable delay circuit (variable delay means), (24)...motion vector signal correction circuit (motion vector correction means). Figure 4 o6 Zu9 Figure 6 Figure 7 tel Filem original drawing

Claims (4)

[Claims] (1) In the MUSE decoder that detects the motion vector signal multiplexed on the MUSE signal and performs motion vector correction in the interframe interpolation circuit (7), a smoothed vector signal is created from the value of the motion vector signal. a smoothing means (22) for outputting the same, and a variable delay means for varying the input timing of the MUSE signal input to the interframe interpolation circuit (7) according to the smoothed vector signal from the smoothing means (22). (20); and motion vector correction means (2) for creating a corrected motion vector signal from the motion vector signal and the smoothed vector signal.
4) A MUSE decoder comprising: (2) A switching means (SW2) for supplying the motion vector signal to the interframe interpolation circuit (7) in place of the corrected motion vector signal.
MUSE decoder. (3) A telecine conversion MUSE signal that controls the switching means (SW2) to supply the corrected motion vector signal to the interframe interpolation circuit (7) when the periodicity of the motion vector signal has a predetermined characteristic. 3. The MUSE decoder according to claim 2, further comprising detection means. (4) Telecine conversion MUSE signal detection means that detects a predetermined signal in the control signal, controls the switching means (SW2), and supplies the corrected motion vector signal to the interframe interpolation circuit (7). 3. The MUSE decoder according to claim 2, further comprising: (3').