JPH03243083A - Muse/edtv type converter - Google Patents

Abstract

PURPOSE:To obtain a clear vision video signal of high picture quality effectively utilizing various video information by directly converting a high vision MUSE signal into a non-interlaced clear vision video signal. CONSTITUTION:A video signal 10, a synchronizing signal, a sound signal, and a control signal for band-compressed information are extracted from a digital signal 63 obtained by A/D converting an inputted MUSE signal 61. The levels of the signal 10 and a signal 17 delayed by 2H are alternately set up to 3/8 and 1/8 in each field and added by an adder 22 to obtain a weighted mean signal 23 with the 1/2 level and the signal 23 and a signal obtained by setting up the 1H delay signal 16 of the signal 10 to a 1/2 level are respectively sampled through latch memories 24, 25, the sampled signal is added to either one of signals obtained from the latch memories to which a latch clock whose phase is inverted from that of a clock signal 12 is impressed and the obtained video signal is converted into an analog signal 33, which is synthesized with a synchro nizing signal 69 to output a clear vision video signal 74.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention converts the band-compressed MUSE signal of the so-called high-definition system, which has 1125 scanning lines, to the so-called clear vision signal, which has 525 scanning lines and 60 frames per second. The present invention relates to a system conversion device for converting a video signal into an EDTV video signal.

[Conventional technology]

The so-called high-definition system proposed for high-definition television has a large number of scanning lines, 1125, and the screen aspect ratio is 9:16, which is the same as the conventional NTSC system. In order to receive an image with an NTSC system device, it is necessary to convert the number of scanning lines.

Of the 1125 scanning lines in HDTV, 1035 contain video signals, while in NTSC, 525
Video signals are included in 483 of the scanning lines of the book.

Therefore, among the scanning lines containing high-definition video signals, 69 lines corresponding to the upper and lower ends of the display screen are omitted,
By converting the remaining scanning lines to 1/2, the high-definition video signal can be viewed on an NTSC television receiver.

Therefore, in the odd field of a high-definition video signal, the same video signal and a signal delayed by one horizontal scanning period of the signal are added via a 1/2 level converter, and 2
Outputs the scanning line of the book as one line.

In the even field of the same video signal, the scanning line arrangement is maintained by l:2 interlacing with the odd field, and the input video signal of the same scanning line is output as is one by one, and the number of scanning lines is 1. /2 NTSC format video signal.

On the other hand, from the conventional NTSC video signal, a signal is generated to compensate for the gaps between the scanning lines of the same signal, and the scanning line 525 tree,
ED, so-called clear vision, displays high-quality images using a non-interlaced method with a frame rate of 60 frames per second.
TV receivers are starting to become popular.

[Problem to be solved by the invention] A high-definition broadcasting signal is transmitted as a MUSE signal with a compressed band, and the MUSE signal is received and demodulated and then output.
The SE signal is decoded into high-definition video and audio signals.

In order to view the high-definition signal on a conventional television receiver, the restored high-definition video signal is further
It is necessary to convert it into an SC video signal, and the conversion device is complicated and expensive.

Further, as mentioned above, since the circuit configuration through which signals pass is different between odd and even fields, timing shifts in video signals occur, which tends to cause image quality deterioration such as flicker.

In addition, since the video signal is in the interlaced NTSC format, even if it is a TV receiver with a high image quality after the video signal input stage in recent years or a TV receiver using the clear vision method, the rich video information of high-definition can be effectively used. It was not something that was used for this purpose.

[Means to solve the problem]

The video signal for each field of high-visibility, which is an interlace method of 30 frames per second and ■=2, is converted into an image signal of one frame each, and is made into a video signal of 60 frames per second and a non-interlace method.

Furthermore, 37.5 lines corresponding to the upper and lower ends of 562.5 video signal scanning lines for each field are omitted, resulting in a clear vision video signal of 525 lines per frame.

A/D converts high-definition system band compressed MUSE signal
It is converted into a digital signal, and a video signal is extracted from the digital signal.

A clear vision video signal is generated by weighted averaging of three adjacent sampling information on three consecutive scanning lines of the extracted video signal.

The weighted average signal is output after timing adjustment as a clear vision video signal using a clock signal and a synchronization signal, converted into an analog signal, and output as a clear vision video signal.

[Effect]

In the block diagram of an embodiment of the MUSE/EDTV format conversion device shown in FIG.
Input the E signal.

The inputted MUSE signal 6 is A/D converted into a digital signal 63, from which a video signal IO1 synchronization signal, an audio signal, and a control signal of band-compressed information are extracted.

In the video signal processing section 72 in FIG.
The E system digital video signal 10 is directly converted into a clear vision system video signal, converted into an analog video signal 33, and then combined with a synchronization signal 69 and output.

FIG. 1 shows a detailed block diagram of the video signal processing section 72 involved in the conversion process of the MUSE signal into a clear vision video signal according to the present invention.

Digital video signal I extracted from input MUSE signal
A signal 16 delayed by one horizontal scanning period and a signal NOR delayed by two horizontal scanning periods are outputted via the delay circuit 14 and I5 of one horizontal scanning period.

In order to convert each interlaced field signal of the MUSE signal into a non-interlaced frame signal, it is necessary to correct the misalignment of scanning lines between adjacent fields of the input video signal 10.

Therefore, the levels of the input video signal 10 and the signal 17 delayed by two horizontal scanning periods are alternately set to 3/8 and 1/8, or 1/8 and 3/8, respectively, for each field.
8, and a weighted average signal 23 with a level of 1/2 is obtained.

As described above, the generation of clear vision video signals is
Due to the circuit configuration based on the interpolation method of each sampling signal on the adjacent scanning line, the circuit also functions as a filter, and can reduce aliasing signals in the MUSE signal whose band has been compressed by sampling.

Furthermore, as shown in the schematic diagram of FIG. 4, the sampling points of the MUSE signal in the high-definition video signal are delayed by 1/2 clock cycle from the sampling points of adjacent scanning lines in the same field.

The delay of sampling points between such adjacent scanning lines is M
Since this is omitted in the signal processing process of the sampling signal in the USE encoder, only the delay information at the same sampling point is sent as a control signal in the MUSE signal together with the video signal.

In the MUSE decoder that received the broadcast signal,
It is necessary to correct the delay between scanning lines of the video signal to be reproduced based on the delay information of the sampling point included in the control signal.

A video signal separation section 66 shown in the block diagram of FIG. 5 separates and outputs the video signal 10, and also separates and outputs the control signal.

The delay signal 13 of the sampling point included in the control signal output from the video signal separator 66 generates a clock signal that is in phase and in opposite phase to the clock signal 12 output from the synchronization signal separator 64, and is used for each scanning line. The latch clocks 26 and 27 which are alternately switched each time are output.

A waveform diagram showing the polarity switching relationship of the latch clocks 26 and 27 is shown in FIG.

The 1/2 level weighted average signal 23 and the 1/2 level signal of the one horizontal scanning period delayed signal 16 of the video signal IO are sent to the latch memories 24 and 25 via the latch memories 24 and 25, respectively. applying and sampling the latch clocks 26 and 27;
The signal of one of the latch memories to which a latch clock having a phase opposite to that of the clock signal 12 is applied is delayed by 1/2 clock cycle to correct the delay in sampling points between scanning lines.

The 1/2 level weighted average signal and the human video signal 10
The output signals of the latch memories 24 and 25 corrected for the 1/2 clock cycle delay of the signal with the 1/2 horizontal scanning period delayed signal I6 at 1/2 level are added together and converted into an analog video signal 33. Output.

The video signal obtained through the arithmetic processing as described above is converted into an analog signal 33, which is combined with the synchronization signal 69 generated by the synchronization signal generation section 68, and a clear vision video signal 74 is output.

〔Example〕

A/D converts MUSE signal 6I output from satellite broadcasting receiver, etc.
The digital signal 63 is inputted to the converter 62 and outputted from the A/D converter 62, and is supplied to each of the synchronizing signal separator 64, the video signal separator 66, and the audio signal separator.

The synchronization signal separation section 64 generates a clock signal I2 synchronized with the input signal and supplies it to the A/D conversion section 62 to configure a loop circuit. Discrimination unit 70,
The signal is supplied to a video signal processing section 72 and an audio signal processing section.

The video signal 10 output from the video signal separation section 66 and the field discrimination signal I output from the field discrimination section 70
I is supplied to the video signal processing section 72, which converts the inputted MUSE system video signal into a clear vision system video signal 33 and outputs it.

Details of the video signal processing section 72 will be explained with reference to a block diagram of main parts in FIG.

Digital video signal 1 extracted from input MUSE signal
0 is supplied to the first input of the selector 18 via the delay circuit 14 and I5 for l horizontal scanning period, and the same video signal IO is supplied to the second input of the selector 18.

The selector 18 outputs the signals supplied to the first and second inputs from the first and second output terminals, respectively, or switches the outputs and outputs the signals supplied to the first and second inputs from the field discrimination signal 11 output from the field discrimination section 70. 2 and 1st
Output from the terminal.

The outputs from the first and second output terminals of the selector 18 are connected to 1/8 and 3/8 level converters 19, respectively.
and 20, and the output of each converter 19, 20 is input to an adder 22, which outputs a 1/2 level addition signal 23.

The output of the adder 22 is passed through the latch memory 24, and the output signal I6 of the delay circuit No. 4 for one horizontal scanning period is branched and supplied to the 1/2 level converter 21. The output of is sent to the adder 2 via the latch memory 25.
Supply to 8.

The clock signal I2 supplied by the synchronization separator 64 is passed through a switch circuit composed of an inverter circuit 30 and exclusive OR circuits 3 and 32, and the clock signal I2 has opposite polarity to the control signal supplied together with the video signal 10. Latch clocks 26 and 27 whose polarity is switched every horizontal scanning period by the delayed signal 13 of the sampling point are supplied to the latch memories 24 and 25, respectively.

The output of the adder 28 is supplied to the D/A converter 29, which outputs an analog video signal 33, and the synchronization signal generator 68
It is supplied to a signal synthesizing section 73 together with a synchronization signal 69 outputted by a clear vision system video signal 74.

The video signal processing is related to the luminance signal of the video signal, but a similar circuit (not shown) processes the color difference signal (
B-Y) and (R-Y) are also converted into clear vision color difference signals of 525 non-interlaced scanning lines and 60 frames per second and output.

R converted into three color signals of red, green, and blue by a combination of the luminance signal, color difference signal, and synchronization signal.
It is possible to output a GB signal, a synchronization signal and a luminance signal, a Y-C separated signal converted into two types of composite color difference signals, and a composite signal in which the luminance signal, color difference signal, and synchronization signal are combined.

〔Effect of the invention〕

With the simple circuit configuration of the present invention, by directly converting a high-definition MUSE signal into a non-interlaced clear vision video signal, the rich video information of high-definition can be effectively utilized, and high-quality video for clear vision can be produced. It can be a signal.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the video signal processing section of the MUSE/EDTV format conversion device of the present invention, FIG. 2 is a waveform diagram of the lunch clock, and FIG. 3 is a schematic diagram of the sampling of the MUSE signal.
FIG. 4 is a block diagram of an embodiment of the MUSE/EDTv system conversion device. In the figure, 10 is a digitized video signal of the MUSE signal, II
is a field discrimination signal, 12 is a clock signal, 13 is a sampling point delay signal, 14 to 15 are delay circuits, 16
is a video signal delayed by 1 horizontal scanning period, NOA is a video signal delayed by 2 horizontal scanning periods, I8 is a selector, I9 is a 1/8 level converter, 20 is a 3/8 level converter, and 2 is a 1/2 level converter. , 22 and 28 are adders, 23 is an intermediate weighted average signal, 24-25 are latch memories, 26-27 are clock signals for latch memories, 29 is a D/A converter, 30 is an inverter, 31-32 are exclusive OR gate, 33 analog video signal, 6 MUSE signal, 62 A/D converter, 63 digimole MUSE signal, 64 synchronization signal separation section, 66 video signal separation section, 68 synchronization signal generation 69 is a synchronization signal, 70 is a field discrimination section, 72 is a video signal processing section, 73 is a signal synthesis section, and 74 is an output video signal.

Claims (1)

[Claims] The video signal extracted by converting the high-definition MUSE signal into a digital signal and the 2 horizontal scanning period delayed signal of the same video signal are each 3/8 in the odd field.
and 1/8 level ratio, and in even fields, they are added at a level ratio of 1/8 and 3/8, respectively, and the added signal and the one horizontal scanning period delayed signal of the video signal are added to 1/2. EDT
MUSE/EDT characterized by having a video signal of V
V format conversion device.