JPH0461493A - Recording/reproducing system for video signal - Google Patents

Abstract

PURPOSE:To attain recording/reproduction of a video signal with high picture quality by converting a time division multiplex signal outputted from a Time Compressed Integration(TCI) encoder into an analog signal and then recording the analog signal onto a recording medium. CONSTITUTION:A sequential scanning signal whose scanning lines are 1125 are interleave-processed by a vertical filter 6b at an interval of one line, and a luminance signal Y' and a line sequential chrominance signal C' whose data quantity is reduced are subject to time base compression for each line by a TCI encoder 11. An output of the TCI encoder 11 is converted into an analog signal by a D/A converter 12, the band of the signal is limited by a low pass filter 13 and the result is outputted via an output terminal 14 and recorded on a recording medium. Thus, the recording/reproduction of the video signal is attained with high picture quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a new video signal recording/playback method that enables recording/playback of high-quality video signals.

[Conventional technology]

As the screens of television receivers have recently become larger, flickering and blurring on the screen, which were not so noticeable in conventional receivers due to visual characteristics, have become noticeable. For this reason, there is a growing demand for improved picture quality, and various high-definition television systems are being considered. For example, improvements to the current method
IDT V (Improved Definition) improves vertical resolution by sequential scanning without modification.
On Television) system, we aim to improve vertical and horizontal resolution by making necessary improvements and changes while maintaining compatibility with the current system.
ded Definition Te1vision
) system, which pursues the ideal next-generation television system without being bound by the current system.
h Definition Te1evision) method, etc.

[Problem to be solved by the invention]

In this way, various high-definition television systems have been proposed,
Some of them have already been put into practical use and broadcasting has begun. On the other hand, VTR (Video Tape Rec
order) and VDP (Video Disk
In the field of packaged media such as NTSC Player, video signals are still only recorded/played using the current NTSC system, and compared to the advancement of high image quality in the broadcasting field, this field, especially the field of consumer packaged media, is Improving the quality of video is lagging behind.

An object of the present invention is to propose a new video signal recording/playback method that enables recording/playback of high-quality video signals on package media such as VTRs and VDPs.

[Means for Solving the Problems] The video signal recording method according to the present invention interpolates the scanning lines of an input high-definition signal using a median filter to convert them into a sequential scanning signal, and the number of scanning lines of the converted sequential scanning signal is is reduced by a vertical filter to reduce the number of scanning lines to 52.
A method converting means for obtaining five sequential scanning signals; and a method converting means for separating the sequential scanning signals output from the method converting means into a luminance signal and a color signal consisting of two color difference signals, and converting the luminance signals into two-dimensional signals. a thinning means for reducing the amount of data by applying sub-sampling, and reducing the amount of data by applying two-dimensional sub-sampling after sequentially thinning out pixels for each line of the color signal; A TCI that compresses the time axis of the luminance signal and color signal output from the means for each line, and outputs the time-division multiplexed signals.
encoder, and is configured to convert the time division multiplexed signal outputted from the TCI encoder into an analog signal and then record it on a recording medium.

In addition, the video signal reproduction method according to the present invention converts a sequential scanning signal read from a recording medium, in which a luminance signal and a chrominance signal are time-axis compressed and time-division multiplexed into a luminance signal and a chrominance signal. TC that separates into two parts, expands the time axis, and outputs
The luminance signal and color signal output from the I decoder and the TCI decoder are passed through an interpolation circuit to restore the pixels thinned out during recording, and separate and output the two multiplexed color signals. interpolation means; and inverse matrix means for generating three primary color RGB signals from the luminance signal and two color signals output from the interpolation means, and converts the three primary color ROB signals output from the inverse matrix means into analog signals. The configuration is such that it is converted into a signal and output as a sequential scanning signal with 525 scanning lines.

[For production]

In the configuration of the present invention, a high-definition signal subjected to interlaced scanning is converted into a sequential scanning signal by interpolating the number of scanning lines by a median filter, and then thinned out and converted into a sequential scanning signal with 525 scanning lines. is converted to Among the converted progressive scanning signals, the luminance signal has its pixel count reduced by half by a two-dimensional sub-sampling filter, and the two color signals are thinned out line by line and then line-sequentialized. , the number of pixels is reduced by a factor of 2 by a two-dimensional subsample filter. The luminance signal and color signal thinned out in this way are time-axis compressed line by line, time-division multiplexed, and recorded on a recording medium.

During reproduction, the time-division multiplexed luminance signal and chrominance signal are separated, and the pixels thinned out by the subsample filter during recording are interpolated by an interpolation circuit. The color signal is further separated into two color difference signals, and each color difference signal is subjected to horizontal interpolation and vertical interpolation to produce two color difference signals P and l.
and P, are restored.

The luminance signal Y and two color difference signals PIl restored in this way
, P and are converted into three primary color RGB signals by an inverse matrix circuit, with 525 scanning lines and an aspect ratio of 16:9.
, is supplied to the television receiver as a progressively scanned component signal with a frame frequency of 60 Hz. By using a wide aspect ratio EDTV compatible television receiver, it is possible to reproduce high-quality video signals.

[Embodiment] Recording thread Figure 1 is a block diagram showing an embodiment of a recording system of the video signal recording/reproducing system according to the present invention.

In FIG. 1, a componentized high-definition RGB signal is band-limited by a low-pass filter (LPF) 1 and converted into a digital signal by an AD converter (ADC) 2. The converted digital RGB signal is separated into a luminance signal Y and two color difference signals P, , P, by the matrix circuit 3. The two separated color difference signals PR+pH are band-limited by a low pass filter (LPF) 4, and then dot multiplexed line by line by a multiplexer (MPX) 5 and converted into a color signal C.

The luminance signal Y and chrominance signal C thus obtained are transmitted to a system conversion circuit 6 consisting of a vertical interpolation circuit 6a and a vertical filter 6b.
A high-definition signal with 1125 scanning lines, which is an interlaced scanning signal, is converted into a sequential scanning signal with 525 scanning lines.

FIG. 2 is a block diagram showing the configuration of the system conversion circuit 6. As shown in FIG. In the figure, a vertical interpolation circuit 6a is a circuit that converts a high-definition signal, which is an interlaced scanning signal, into a sequential scanning signal by interpolating the scanning lines, and is a circuit that stores a horizontal scanning line signal for one line of the high-definition signal. A memory 20, a field memory 21 which is connected to the output of the line memory 20 and stores scanning signals for one field, and a field memory 2.
The comparator circuit 22 is configured to receive three signals: the output a of the line memory 20, the output a of the line memory 20, and the input high-definition signal C. The comparison circuit 22 is composed of a 3-point median filter that outputs the center value when the density values of pixels in the local area are arranged in order of magnitude. Median filters have advantages over local averaging circuits, such as no edge blurring and resistance to noise.

The vertical filter 6b thins out the video signal with 1125 scanning lines converted into sequential scanning by the vertical interpolation circuit 6a every l line, and then cuts the upper and lower lines to create a sequential scanning signal with 525 scanning lines. In the circuit to convert, comparison circuit 2
A line memory 23 is connected to the output of 2 and stores horizontal scanning line signals for one line, an adder 24 adds the input C and output of the line memory 20, and the added value is 172
A multiplier 25 that multiplies the output of the multiplier 25 and a comparator 22
An adder 26 adds the output d of 172 to the added value.
A multiplier 27 that multiplies the input d and the output e of the line memory 23, an adder 28 that adds the input d and the output e of the line memory 23, a multiplier 29 that multiplies the added value by 172, and adds the output of the line memory 20 and the output of the multiplier 29. Adder 30 that adds 1 to the added value
It is comprised of a multiplier 31 that multiplies by /2, and a switch circuit 32 that switches between the output of the multiplier 27 and the output of the multiplier 31 for each field.

Now, as shown in FIG. 3(a), the vertical interpolation time Nl6a
When interpolating pixel d on line Laz of the first field, pixel C on line Lbz of the second field
When input to the line memory 20, the line memory pixel output from the line memory 20 will be the line L one field before output from the field memory 21.
From pixel a on az, a pixel with a median value is selected by the comparator circuit 22 and output as an interpolation pixel d for interpolation. By repeating this operation, a video signal with 1125 sequentially scanned scanning lines is obtained as shown in FIG. 3(b).

The 1125 sequential scanning signals thus obtained are thinned out every other line by the vertical filter 6b.

Now, as shown in ) in FIG. 3, if pixels a to e are defined on lines L1 to L4, pixel C will
At the time when the pixel is input to the line memory 20, the pixel d is output from the output of the comparator 22, and the pixel e is output from the output of the line memory 23. If the switch circuit 32 is switched to the multiplier 27 side in this state, the weighted sum of pixels S, d, and c is calculated as shown in the following equation, and pixel d' is obtained.

Furthermore, if the switch circuit 32 is switched to the multiplier 31 side in this state, a weighted sum is obtained from pixels S, d, and e as shown in the following equation, and is output as pixel b'.

Switching of the switch circuit 32 is performed for each field.

The video signal converted into a sequential scanning signal with 525 scanning lines by the system conversion circuit 6 is then supplied with the luminance signal Y to the sub-sample filter, and the data amount is reduced by half.
The color signal C is reduced to a low pass filter 89 and a thinning line sequential circuit 9. It is fed to a sub-sample filter 10 to reduce the amount of data by a factor of two.

FIG. 4 is a block diagram showing the configuration of the subsample filter 7. This sub-sampling filter 7 is a circuit that performs sampling by multiplying every 3 lines x 3 pixels of the sequential scanning signal output from the conversion circuit 6 by a matrix-like coefficient of 3/3, thereby halving the amount of data. .

The second sub-sample filter 7 includes a two-phase dividing circuit 40 that separates the input sequential scanning signal of 525 scanning lines every other pixel for each line and time-divides it into two-phase data. The two-phase data is alternately switched line by line by a switching circuit 41.

One output of the switching circuit 41 is input to a line memory 42 that stores one line of scanning line signals, and the other output is
The signal is input to a line memory 43 that stores scanning line signals for 1 line - 1 pixel. The output of the line memory 43 is transmitted to the first and second delay circuits 4 that store scanning line signals for one pixel.
4 and 45, and the output of the delay circuit 45 is input to the line memory 4 which stores the scanning line signal for "1 line - 1 pixel".
6 will be man-powered. The input and output of the delay circuit 440 are alternately outputted by a switch circuit 47 which is switched on a line by line basis, and the input and output of the delay circuit 45 are alternately outputted by a switch circuit 48 which is also switched on a line by line basis. The outputs of switch circuits 47 and 48 are added by adder 49.

Further, the output of the line memory 42 is converted into a coefficient by a multiplier 50.
is input to the adder 51 after being multiplied. The output of the adder 49 is input to this adder 51 after being multiplied by 2 in a multiplier 52, and the output of the line memory 46 is input after being multiplied by 3 in a multiplier 53. ,
Further, the line memory 430 input is multiplied by a coefficient of 3 in a multiplier 54 and inputted.

In this configuration, as shown in FIG. 5(a), sequential scanning signals of 525 scanning lines are transmitted from the conversion circuit 6 to
(pixel P1°, PI+9...), L2 (pixel P2
゜yP2゜...), L3 (pixel P3゜IP21t...
)..., the two-phase dividing circuit 40 takes in the pixels of each line at a frequency of 2fs, and
As shown in FIGS. 5(b) and 5(C), each line is separated into every other pixel and output as two-phase data at the timing of frequency fs. Therefore, from the two-phase dividing circuit 40, the line La is output as the output signal Do.

(Pixel P, o, P +z, "・), Laz (Pixel Pzo*Pzz...) = Lat (Pixel P3゜t P
3□,...),... are output, and the line Lb+ (pixel P) is output as the output signal D1.

gPI:ly...), Lb2 (pixel P2+, 73t
), Lb3 (pixel P:1IIP3:l,...
), ... are output.

The output signals DO and Dl are alternately switched line by line by the switching circuit 41, and the line memory 42 has the line La+
→Lbz→La3→Lba→... are output, and the lines Lb+→Laz→Lb, →La4 are output to the line memory 43.
→... is output.

Now, when the switching circuit 41 outputs the pixel P3° to the line memory 42 and at the same time outputs the pixel P31 to the line memory 43, the line memory 42 outputs the pixel P2I, and the line memory 43 outputs the pixel P2I. Pixel P2□
is output, the delay circuit 44 outputs the pixel P2°, and the line memory 46 outputs the pixel P11.

Since the switch circuits 47 and 48 are switched to the illustrated state, the adder 51 calculates and outputs the sub-sampled pixel P21' as shown in the following equation.

P 21' - + P 21+ 2 (P 2゜0P
2□)+ to 3 (P z+ P , l+) In this way, each pixel is alternately thinned out every other pixel on each line and aligned vertically at the same time, as shown in FIG. 5(d). It is output as a luminance signal Y'.

The color signal C output from the system conversion circuit 6 is shown in FIG.
As shown in Fig. 6, the dots are multiplexed line by line, and after being band-limited by a vertical low-pass filter 8, they are processed by a thinning line sequential circuit 9 to become a line-sequential color signal as shown in Fig. 6 Φ). The signals are thinned out, shifted and aligned in the vertical direction as shown in FIG. 6(C), and input to the subsample filter 10. In the subsample filter 10, after removing aliasing distortion in advance,
As shown in d), each pixel is alternately thinned out every other pixel in each line, and shifted and aligned in the vertical direction as shown in FIG.
’ is output.

The luminance signal Y' and the line sequential color signal C' whose data amount has been reduced in this way are processed by TCI (Time Compress).
ed Integration) The encoder 11 compresses the time axis line by line and time-division multiplexes the signals. T
The output of the CI encoder 11 is converted into an analog signal by a DA converter 12, band-limited by a low-pass filter 13, and outputted via an output terminal 14, and then output by a magnetic tape recording circuit or an optical disk recording circuit (not shown). It is recorded on a recording medium such as a video tape or a laser disc.

FIG. 7 is a block diagram showing an embodiment of the reproduction system of the video signal recording/reproduction method according to the present invention.

Depending on the recording system mentioned above, video tape or laser
A video signal recorded on a recording medium such as a disk is read out by a magnetic tape playback circuit or an optical disk playback circuit (not shown), band-limited by a low-pass filter 60, and then converted into a digital signal by an AD converter (ADC) 61. The signal is converted into a signal and input to the TCI decoder 62. T.C.
The I decoder 62 separates the luminance signal Y' and color signal C' which are time-division multiplexed for each line, expands the time axis, and outputs the signal. The luminance signal Y' is supplied to an interpolation circuit 63,
Data thinned out by subsampling during recording is interpolated.

FIG. 8 is a block diagram showing the configuration of the interpolation circuit 63.

This interpolation circuit 63 is a circuit that restores thinned out pixels by multiplying the luminance signal Y' output from the TCI decoder 62 by 3 x 3 matrix coefficients for every 3 lines x 3 pixels. , the signal input to the input terminal 80 is input to the line memory 81 which stores the scanning line signal for 1 line - 1 pixel j, and the output of the line memory 81 is the first and second line memory 81 which stores the scanning line signal for one pixel. Second delay circuit 8
2 and 83, and the output of the delay circuit 83 is input to the line memory 8 which stores the scanning line signal for "1 line - 1 pixel".
4 is input. The input and output of the delay circuit 82 are alternately outputted by a switch circuit 85 which is switched on a line-by-line basis, and the input and output of the delay circuit 83 are alternately outputted with a switch circuit 86 which is also switched on a line-by-line basis. The outputs of the switch circuits 85 and 86 are added by an adder 87, and the added value is multiplied by a coefficient of 12 by a multiplier 88 and then input to an adder 89. The input to the line memory 810 and the output from the line memory 84 are added to the adder 89 by an adder 90, multiplied by a coefficient 13 by a multiplier 91, and then inputted to the adder 89. Adder 89
The output of is inputted to one movable terminal a of the switch circuit 92.

The other movable terminal of the switch circuit 92 is connected to the delay circuit 8.
The output of 2 is multiplied by a coefficient 11 in a multiplier 92 and then inputted. This switch circuit 92 is switched every clock CK (frequency fs).

In this configuration, as shown in FIG. 9(a), the input terminal 80 receives a sequential scanning signal of 525 scanning lines from the TCI decoder 62 on the line Lx (Pro', p+□'
...) t L2 (P 21' s P 24
1'? ...).

It is input as Ls (P3°, P32', . . .) . Now, from the input terminal 80 to the line memory 8
When pixel P3□′ of line L8 is input for 1,
Pixel P23' is output from line memory 81, and pixel P2. ' is output and the line memory 84
Pixel P1□' is output from. When switch circuits 85 and 86 are switched to the state shown, adder 8
From 9 onwards, pixel P2□ is calculated and interpolated as shown in the following equation.

P2□=lt (P2I' + P23') + lz (
P + z' + Pz
When switched by K, pixel Pal is output.

By repeating this operation, a restored progressive scanning luminance signal Y with 525 scanning lines is output as shown in FIG. In addition, the coefficient K. The relationship between and coefficient 17 is 1. , =2XKh.

T(l line sequential color signal C' output from the decoder 62
(FIG. 6(e)) is the vertical interpolation circuit 64, and FIG.
Zero data is inserted as shown in a), and the 10th
Pixels in the vertical direction are interpolated as shown in Figure (b). The output of the vertical interpolation circuit 64 is input to a vertical interpolation line sequential return circuit 65, where it is returned to line sequential order and vertically interpolated at the same time, as shown in FIG. 10(C). Next, the horizontal interpolation circuit 6
6, the two color signals are horizontally interpolated separately, and the two color difference signals P
, and P are restored.

The luminance signal Y and color difference signal PR+P thus obtained are converted into three primary color RGB signals by an inverse matrix circuit 67, converted into analog signals by a DA converter 68, band-limited by a low-pass filter 69, and output. It is output from the terminal 70.

Therefore, from the output terminal 70, a progressive scanning signal having 525 scanning lines, an aspect ratio of 16:9, and a frame frequency of 60 Hz is supplied as a component RGB signal to a television receiver (not shown). As a television receiver, for example, if a wide aspect ratio HDTV compatible device is used, high-quality video signals can be reproduced.

〔Effect of the invention〕

According to the present invention, a component signal having 525 scanning lines obtained by sequential scanning is recorded on a recording medium and reproduced, so that it is possible to record/reproduce a high-quality video signal.

Furthermore, since the number of scanning lines is 525, it can be easily converted into a video signal of the current NTSC system by incrementing, and compatibility with the current system can be achieved.

In addition, when converting a high-definition signal into a sequential scanning signal with 525 scanning lines, we interpolated the scanning lines using a median filter and then thinned out the scanning lines.
With a simple configuration, you can convert formats with high image quality for both videos and still images.

In addition, since the amount of data is compressed by performing intra-field subsampling during recording, it is possible to reduce the amount of data to be recorded, and the frame memory is only needed for one frame, reducing costs. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a video signal recording system according to the present invention, FIG. 2 is a block diagram of the format conversion circuit in FIG. 1, and FIG. 3 shows the operation of the vertical interpolation circuit in FIG. Figure 4 is a block diagram of the subsample filter in Figure 1. Figure 5 is a diagram to explain the operation of the subsample filter. Figure 6 is the sequential order of the thinning lines in Figure 1. A block diagram of the circuit. FIG. 7 is a block diagram showing an embodiment of the video signal reproduction system according to the present invention. FIG. 8 is a block diagram of the interpolation circuit in FIG. 7. FIG. 9 is a block diagram showing the interpolation operation of the luminance signal. FIG. 10 is a diagram for explaining the color signal interpolation operation in FIG. 7. 6... System conversion circuit, 7... Subsample filter, 9... Thinning line sequential circuit, 10... Subsample filter, 11... TCI encoder, 62...
・T(l decoder, 63... interpolation circuit, 64... vertical interpolation circuit, 65... line sequential return circuit.

Claims (3)

[Claims] (1) The scanning lines of the input high-definition signal are interpolated by a median filter and converted into a progressive scanning signal, and the number of scanning lines of the converted progressive scanning signal is reduced by a vertical filter to generate a progressive scanning signal with 525 scanning lines. a system conversion means for obtaining the data; and a system converter that separates the sequential scanning signal outputted from the system conversion system into a luminance signal and a color signal consisting of two color difference signals, and performs two-dimensional subsampling on the luminance signal. 1 for each of the above color signals.
a thinning means for reducing the amount of data by thinning line sequentially thinning out pixels for each line and then applying two-dimensional subsampling; and compressing the luminance signal and color signal output from the thinning means on a time axis for each line; T to output by time division multiplexing
1. A video signal recording method comprising: a time-division multiplexed signal outputted from the TCI encoder, which converts a time-division multiplexed signal outputted from the TCI encoder into an analog signal and then records the signal on a recording medium. (2) The sequential scanning signal read from the recording medium, in which the luminance signal and chrominance signal are time-axis compressed line by line and time-division multiplexed, is separated into the luminance signal and chrominance signal and time-axis expanded. The TCI decoder outputs, and the luminance signal and color signal output from the TCI decoder are passed through an interpolation circuit to restore the pixels thinned out during recording, and separate the two multiplexed color signals. an interpolation means for outputting, and an inverse matrix means for generating three primary color RGB signals from the luminance signal and two color signals output from the interpolation means, and the three primary color RGB signals output from the inverse matrix means, A video signal reproduction method characterized in that each signal is converted into an analog signal and output as a sequential scanning signal with 525 scanning lines. (3) Separating the sequential scanning signal with 525 scanning lines into a color signal and a luminance signal consisting of two color difference signals, and applying two-dimensional subsampling to the luminance signal to reduce the amount of data, and For each color signal, the pixels are thinned out line by line and then subjected to two-dimensional subsampling to reduce the amount of data, and the luminance signal and color signal after the data amount reduction are time-division multiplexed for each line. a recording means for recording on a recording medium; and a recording means for separating the luminance signal and color signal which are time-division multiplexed and recorded on the recording medium, and interpolating the pixels thinned out during recording to sequentially print 525 scanning lines. A recording/reproducing method for a video signal, comprising: a reproducing means for obtaining a scanning RGB signal.