JPH04196787A - System converter - Google Patents

Abstract

PURPOSE:To realize the system converter not requiring complicated movement detection processing by using movement control information included in a MUSE signal so as to covert a frame frequency. CONSTITUTION:A signal with a field frequency 60Hz fed from a scanning line conversion circuit 110 is controlled by a write control circuit 202 is written in a frame memory 200 and read by a read control circuit 203 operated at a field frequency 59.94Hz. Since the write side system overtakes the readout side system without any modification to the original system, a skip signal 201 is used to stop the write and to implement one frame skip. Control information inserted in a MUSE(Multiple Sub-Nyquist Sampling Encoding) signal is detected by a control information detection circuit 8 and when the information is scene change and complete still signal information, it is fed to the write control circuit 202 by using the skip signal 201. Thus, the field frequency signal is converted into a standard television signal without need of complicated movement detection.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a system conversion device for converting a high-definition television signal (MUSE system) band-compressed using the sub-Nyquist sampling system into a current standard television signal. .

Conventional technology MUSE is an effective technology for compressing and transmitting broadband high-definition television signals to a practical level band.
(Multiple 5ub-Nyquist's
AmplifyingEncoding) method has been proposed (Ninomiya, et al., “Satellite 1-channel transmission method for high-definition television (MUSEL1 Television Society Technical Report TEBS9)
5-237 pages to 42 pages).

As stated in the paper, this method uses 4:1 sub-Nyquist sampling to compress a broadband high-definition television signal once in four fields, compressing the band to about 1/4 before transmitting it. be. This band-compressed high-definition television signal (hereinafter referred to as MUSE signal) is converted into the original broadband high-definition television signal by superimposing the four fields using intra-field, inter-field, and inter-frame interpolation in the MUSE decoder on the receiving side. Restored to high quality TV signal.

In addition, when recording high-definition television broadcasts, you can use a MUSE-based VCR (Video Ca5sette Recorder).
er) or a wideband high-definition VCR. However, these VCRs are expensive and it is thought that it will take a considerable amount of time for them to become popular in general households.

Therefore, for the time being, the standard television signal (N
Using a VCR compatible with the TSC method is considered an effective means. For this purpose, a format conversion device is required to convert the MUSE signal to a standard television signal.

First, an outline of a MUSE type television receiver will be explained with reference to FIG. In Figure 3, 1 is MUS
Input terminal for inputting the E signal, 2 is an A/D conversion circuit, 3 is a still image processing circuit, 31 is an interframe interpolation circuit, 32 is an interfield interpolation circuit, 4 is a video processing circuit, 41 is an intrafield Insertion circuit, 5 is motion detection circuit, 6 is mixing circuit, 7
8 is a TCI decoder, and 8 is a control information detection circuit for detecting control information in the MUSE system.

In the conventional MUSE receiver configured as described above, the MUSE signal input from input terminal 1 is
/D conversion circuit 2, the output signal of which is applied to a still image processing circuit 3 comprising an interframe interpolation circuit 31 with a frame memory and an interfield interpolation circuit 32 with a field memory, and a line memory. A moving image processing circuit 4 and a motion detection circuit 5 are composed of a field interpolation circuit 41 and a motion detection circuit 5.
and is supplied to the control signal detection circuit 8. The signal in the still image area is subjected to interpolation processing in the still image processing circuit 3 using still image information of sample points for four fields, and is supplied to one of the mixing circuits 6. The signal in the moving image area is subjected to interpolation processing using only the sample points within the field transmitted by the moving image processing circuit 4, and is supplied to the other input of the mixing circuit 6.

The motion detection circuit 5 detects the amount of motion based on the correlation between one frame or two frames of the MUSE signal. The detected amount of motion is connected to a mixing circuit 6. The mixing circuit 6 performs mixing processing on the signals from the still image processing circuit 3 and the moving image processing circuit 4 according to the amount of motion from the motion detection circuit 5, and generates TCI (
Tia+e-Coipressed-Integra
) is supplied to the decoder 7. TCI decoder 7
Then, time axis compression and decoding processing is performed to return the time-division multiplexed color signal to its original time axis. Control information detection circuit 8
detects various control information inserted on the transmitting side, and
Controls the decoding process of E. For example, when control information for completely still processing or scene change processing is detected in the control information regarding motion, the output signal of the motion detection circuit 5 is controlled, and the decoding processing of MUSE is forcibly controlled to still image processing or video processing. . Other control information includes:
This includes motion vector information, subsample phase information, etc.

Through the above processing, the MUSE signal is restored to the original wideband high-definition television signal.

Next, convert the NUSE TV signal to standard television (NUSE).
TSC system) is displayed on the receiver, and the standard TV signal V
The operation of the converting device for recording on CR will be explained with reference to FIG. Here, the conversion between luminance intervals will be explained. In FIG. 4, 1 is an input terminal for inputting a MUSE signal, 2 is an A/D conversion circuit, 100 is an aliasing interference removal circuit, 110 is a scanning line number conversion circuit, and 120 is an aspect conversion circuit.

First, the input MUSE signal is supplied to the A/D conversion circuit 2, and the output signal is sent to the aliasing interference removal filter 100.
is input. The aliasing interference removal filter 100 removes aliasing interference of high-definition components in the vertical direction that occurs when scanning lines are thinned out. The signal from which the vertical high-definition component has been removed has its scanning lines thinned out in a scanning line number conversion circuit 110, and is converted into a number of 525 scanning lines, which is the current standard television signal. This can be done for example by writing/
This can be easily achieved by using a memory or the like that operates asynchronously for reading, by writing to the memory at the signal rate of a high-definition television signal, and reading out at the signal rate of a standard television signal. The output signal of the scanning line number conversion circuit 110 is supplied to the aspect conversion circuit 120, and is converted from the 16:9 MUSE system to the 4:3 NTSC system. The conversion method is the fifth
As shown in the figure, all the information is displayed (Fig. 5A), which is converted into a display with left and right gaps (Fig. 5B).

There is also an EDTV system that aims to improve image quality, and one of its goals is to achieve a 16:9 wide screen. As a method compatible with such a receiver, the aspect ratio conversion circuit 120 described above is not necessary.

The standard television signal converted as described above can be displayed on a standard television receiver or recorded using a VCR.

Problems to be Solved by the Invention However, with the configuration described above, the MUSE method has 1125 scanning lines and a frame frequency of 30 Hz (field frequency: 60Hz), so simply converting the number of scanning lines is not enough to convert the regular standard signal ( It is not possible to convert the NTSC system.In other words, it is not possible to convert the horizontal frequency (15,734,266 KHz) and field frequency (59,94 Hz) that satisfies the frequency interleaving relationship.Therefore, in a standard system receiver, there is a difference between lines and frames. Since Y/C separation processing cannot be performed between the two, signal processing for high image quality cannot be performed sufficiently.

Furthermore, in order to convert to a standard signal with a field frequency of 60H2, a large-capacity frame buffer memory and complicated motion adaptation processing are required. For example, in a format conversion equipped with 1-frame buffer memory and motion adaptive processing, it is necessary to perform frame skipping once every 33 seconds, so frame skipping is performed by detecting still images and scene changes. converted into a signal. In other words, if there is no motion adaptation processing, the image will be forcibly skipped, resulting in an unnatural state.

In view of the above-mentioned problems, the present invention provides an inexpensive system conversion device that is easy to process and converts the field frequency 60H7 of the MUSE system to the standard system 59.94 Hz.

Means for Solving the Problems The format conversion device for solving the above problems is a format conversion circuit that converts a high-definition television signal band-compressed by a sub-Nyquist sampling method that goes around in four fields into a standard television signal. At least a video processing circuit that processes a video signal of a band-compressed high-definition television signal, a still image processing circuit that processes a still image of a band-compressed high-definition television signal, and one frame of a band-compressed high-definition television signal. A motion detection circuit that detects the amount of motion between frames or between two frames; a control information detection circuit that detects control information included in a MUSE high-definition television signal; and video processing using the amount of motion detected by the motion detection circuit. a mixer that controls the mixing ratio of the signal from the circuit and the signal from the still image processing circuit;
a filter for limiting vertical high frequency components of the signal from the video processing circuit; a scanning line number conversion circuit for converting the signal from the filter into the number of scanning lines of a standard television signal; and the number of scanning lines. The system conversion device includes a frame frequency conversion circuit that converts a signal of the conversion circuit to a frame frequency of a standard television signal, and controls the frame frequency conversion circuit with an output signal of the control information detection circuit.

Effect The present invention uses the motion control information included in the MUSE signal to convert the frame frequency with the above-described configuration, so it is possible to provide a format conversion device that does not require complicated motion detection processing. can.

Embodiment FIG. 1 is a block diagram showing a configuration of a system conversion device according to a first embodiment of the present invention. In Figure 1, 1 is MU
Input terminal for inputting SE signal, 2 is A/D conversion circuit, 3
1 is a still image processing circuit, 4 is a video processing circuit, 5 is a motion detection circuit, 6 is a mixing circuit, 7 is a TCI decoder, 8 is a control information detection circuit, 101 is a vertical low-pass filter, 110 is a scan conversion circuit, 130 is a frame frequency conversion circuit, 120
is an aspect conversion circuit.

The operation of the format conversion apparatus of this embodiment configured as described above will be explained below. In Figure 1, MUS
The decoding process of E is the same as that explained in the conventional example, and the explanation will be omitted. The output signal of the mixing circuit 6 is passed through a vertical low-pass filter 1 consisting of multiple line memories and arithmetic circuits.
The signal is supplied to the scanning line number conversion circuit 110 after removing the aliasing disturbance component caused by thinning out the scanning lines. The scanning line number conversion circuit 110 performs a thinning process to
The frame is converted from 1125 frames to 525 frames and supplied to the field frequency conversion circuit 120.

The field frequency conversion circuit 120 will be explained with reference to FIG. In FIG. 2, 200 is a frame memory, 201 is a skip signal, scene change information and complete still signal information detected by the control information detection circuit 8, 202 is a write sub-part circuit, and 203 is a readout control circuit. Next, the operation will be explained briefly. A signal with a field frequency of 60 Hz supplied from the scanning line number conversion circuit 110 is controlled by the write control circuit 202 and written into the frame memory 200. The signal written in the frame memory 200 has a field frequency of 59.9
It is read out by a readout control circuit 203 operating at 4Hz. If this continues, the write side will overtake the read side, so the write operation is stopped by the skip signal 201 and one frame skip is performed. Skip signal 201 is MU
The control information detection circuit 8 detects the control information inserted in the SE signal, and if it is scene change and complete static signal information, it is supplied to the write control circuit 202, the writing is stopped for one frame, and the frame frequency is converted. is performed and supplied to the aspect conversion circuit 120.

As described above, according to this embodiment, the field station wave number of 60 in the MUSE system is converted to a standard signal (NTSC system) of 59.94.
)1z, the frequency interleaving relationship is satisfied.

In this embodiment, the output signal of the mixing circuit 6 is converted into a standard signal, but the format conversion may be performed from the A/D conversion circuit 2 or the moving image processing circuit 4.

Therefore, in this embodiment, the high-quality television signal decoded by the MUSE decoder can be enjoyed using a high-definition television display or the like, and at the same time, a high-quality standard television signal can be obtained.

Furthermore, in this embodiment, the frame frequency conversion circuit uses the control information inserted into the MUSE signal, so that it can be converted into a standard television signal without requiring complicated motion detection.

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, the field frequency of 60 Hz of the MUSE method is converted into a standard signal (NTSC method>59
．． Since the system is converted to 94 Hz, the frequency interleaving relationship is satisfied, and high-quality processing is possible even on a standard television receiver.

Furthermore, in this embodiment, the frame frequency conversion circuit uses control information inserted into the MUSE signal, so it can be converted to a standard television signal without requiring complicated motion detection, and the circuit can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a system converter according to an embodiment of the present invention, FIG. 2 is a block diagram of a frame frequency converter circuit of the system converter according to this embodiment, and FIG.
The configuration diagram of the SE method decoder, Figure 4 is the conventional MUSE
FIG. 5 is a diagram illustrating a method of displaying a converted video image. 2... A/D conversion circuit, 3... Old still image processing circuit, 4... Video processing circuit, 5... Motion detection 8 circuit, 6... ...Mixed circuit, 7...
TCI decoder, 8...III control information detection circuit, 31...Interframe interpolation circuit, 32...
... Interfield interpolation circuit, 41 ... Intrafield interpolation circuit, 101 ... Vertical high frequency component filter, 110 ... Scanning line number conversion circuit, 120...
... Aspect conversion circuit, 130 ... Frame frequency conversion circuit, 200 ... Frame memory, 201 ... Skip signal, 202 ...
...Write control circuit, 203...Read control circuit. Name of agent: Patent attorney Haruaki Koebi and two others 13θ-m-
Frame 11 wave circuit (Saep circuit diagram 2

Claims (1)

[Scope of Claims] A format conversion device for converting a high-definition television signal band-compressed by a sub-Nyquist sampling method that goes through one round in four fields into a standard television signal, the system converting at least the band-compressed high-definition television signal into a moving image. A still image processing circuit that processes still images of band-compressed high-definition television signals, and a motion detection circuit that detects the amount of movement between one frame or two frames of band-compressed high-definition television signals. a control information detection circuit that detects control information included in a high-definition MUSE television signal; and a control information detection circuit that detects the mixing ratio of the signals from the video processing circuit and the still image processing circuit based on the amount of motion detected by the motion detection circuit. a mixer to control, a filter to limit vertical high frequency components of the signal from the video processing circuit, and a scanning line number conversion circuit to convert the signal from the filter to the number of scanning lines of a standard television signal. and a frame frequency conversion circuit that converts the signal of the scanning line number conversion circuit to a frame frequency of a standard television signal, and the frame frequency conversion circuit is controlled by the output signal of the control information detection circuit. System conversion device.