JP2550299B2 - Video signal playback device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention reduces the amount of information in a video signal.
A recording device suitable for recording after reduction or compression.
The present invention relates to a raw device and a reproducing device. 2. Description of the Related Art Remarkably higher definition than the current television system
Degree, like a so-called high-definition television with high image quality,
It has several times more image information than before, and therefore several times wider bandwidth
The new high-definition television system needed is being studied
I have. In order to put this high-definition television into practical use, a wideband
A video tape recorder that can accurately record and reproduce high-definition video signals
Recorder (VTR), video disc recorder, player
Realization of a recording / reproducing device such as (VDP) has become an important issue.
ing. As a recording / reproducing apparatus compatible with this high-definition television
As a prototype, the technical report VOL.
8, No. Ogeya, 33 (November 1984),
A sentence entitled "VTR for High Definition Television" by Tateno and Tsujikawa
It is reported by the dedication. This VTR is mainly a studio
It was prototyped for use in the
A head drum with a comparatively large diameter is used,
The recording method is divided into multiple channels on the channel.
[0005] [Problems to be solved by the invention]
For widespread use in general households, high-definition television
Downsizing of VTR for use, reducing equipment cost
To enable long-time recording and playback with a small cassette
Has become an important issue.
Miniaturize the drum to make it smaller and lighter and use it
Reduce the number of heads and channels to reduce the circuit scale
Ingenuity such as cost reduction is needed. Only
On the other hand, it is technical because the recording density of the tape increases correspondingly.
Are difficult to record, and the recording time is limited.
It was causing an unacceptable problem. In view of the above, an object of the present invention is to provide a recording medium
Compact and light equipment by reducing the recording density per channel
High-definition TV, etc. that can realize low cost and long time
It is to provide a recording / reproducing apparatus that can handle the above. [0007] To achieve the above object
In addition, in the present invention, the luminance information and the two first and first
The video signal including the color information of 2 is transferred to a predetermined medium on a predetermined channel.
In a device configured to record in the Nell number, the above
Luminance information is specified for each specified block including multiple pixels.
Sampling by frequency reduces the original amount of information in each block.
The amount of processed information after reduction or compression is different
At least two luminance signals (Y1) of the first group and a second group
Luminance signal generating means for generating the luminance signal (Y2) of
Where each of the first and second color information includes a plurality of pixels
Lower than the sampling frequency of the above luminance information for each fixed block
Sampling by frequency reduces the original amount of information in each block.
Above with the amount of information processed after reduction or compression
The first group of color signals (C1) based on the first color information and
Generate a second group of color signals (C2) based on the second color information
Color signal generating means and at least two first groups described above.
And the luminance signals (Y1, Y2) of the second group and the first group and
And the color signals (C1, C2) of the second group are
The transmission amount recorded per unit time becomes almost constant.
Time-division multiplexing means for time-divisional division and multiplexing
The output from the time division multiplex means is used for each channel of the medium.
Recording means for recording the
To collect. Further, in reproducing the data,
The at least two records recorded by the recording means.
The luminance signals (Y1, Y2) of the first and second groups, and
Reproduces color signals (C1, C2) of the first and second groups
Playback means, and the
At least the above-mentioned first group in which the amount of information is reduced or compressed
Complements the processed information amount of any of the second group luminance signals.
Therefore, there is almost the same amount of information as the original amount of the above luminance information.
First conversion means for converting into a luminance information signal for
Reproduced from raw means, at least not reducing the amount of information
The compressed color signals of the first and second groups.
The color information is almost the same as the original color information.
Second conversion means for converting into a color information signal having the same amount of information
And the luminance information signal from the first conversion means and the second information signal.
Output means for outputting the color information signal from the conversion means of
It is characterized by comprising. With the above configuration, the image including the luminance information and the color information is displayed.
Recording medium in which the amount of information in the image signal is reduced or compressed
Recording signal per unit time to record per channel
Transmission amount (that is, transmission of recording signal per channel)
Rate) is reduced and becomes constant, so that the recording signal
It is possible to prevent an increase in recording density by reducing the occupied band. Ma
Also, the amount of information that has been reduced or compressed during playback is
Depleted as appropriate to recover almost the original amount of information
High image quality performance with less is achieved. This operation will be described in detail with a concrete example as follows.
As shown in the embodiment of FIG.
Sampling pixels per line, sampled by
The number of the video signals is n (for example, n = 512).
Multiple m in field or frame (for example,
n × m (= 512 × 2 = 1) over m = 2 lines
024) a block containing pixels is constructed.
The amount of information is reduced or compressed for each
Information amount (for example, n × m / 2 = 512 in terms of the number of pixels)
The first group of luminance signals (Y1) and
The second amount of processed information (for example, n × the number of pixels)
a second group of luminance signals (Y2) having m / 4 = 256)
Is generated. In addition, the above-mentioned first and second color information
The information is that each frequency is lower than the above frequency fs (eg
Sampled at a frequency of fs / 4)
The number of sampling pixels per line is k (for example, k = n / 4
= 128), the number of duplicates in the field or frame
K × h over several h (eg, h = 2) lines
A block including (= 128 × 2 = 256) pixels is constructed.
Information is reduced or compressed for each block.
The amount of information processed based on the first color information (for example,
If the number of pixels is k × h / 2 = 128)
Processing based on the group color signal (C1) and the second color information
Information amount (for example, k × h / 2 = 128 in terms of the number of pixels)
A second group of color signals (C2) is generated. So
Then, the luminance signals of the first and second groups (Y1, Y
2) and the color signals of the first and second groups (C1, C2)
When recording these on each channel of the above medium,
The time occupied by recording each signal
Time-division multiplexing after apportioning based on the amount of information processed
(For example, depending on the number of pixels per block that each signal has
Y1: Y2: C1: C2 = 512: 256: 12
8: 128 = 4: 2: 1: 1 at the ratio of time division multiplexing)
You. This allows the transmission level of the signal to be recorded on each channel.
Is constant for each of the above signals (Y1, Y2, C1, C2).
And the transmission rate remains constant between channels.
You. Next, in the reproduction, the first group and
And the processed information amount of the luminance signals (Y1, Y2) of the second group
Is compensated, the same amount of information as the original amount of the above luminance information
(For example, the number of pixels is n × m = 1024 for each block.
Signal is recovered. Similarly, the first group
And the processed information amount of the second group of color signals (C1, C2)
Are supplemented respectively, and the original information of each of the above two color information is
The same amount of information as the amount of information (eg
(k × h = 256) is restored. Here, red (R), green (G), and blue (B)
Let each occupied band of the three primary color video signals be Bw (block
The total number of pixels is n × m = 1024)
3 × Bw recording band (3 pixels in block)
× n × m = 3072 pieces) is required, but according to the present invention,
For example, with the above configuration, this wideband video signal can be compared
For example, the bandwidth is equivalently reduced to 1/3 (the number of pixels per block
512 + 256 + 128 + 128 = 1024)
Can be recorded and further divided into, for example, 2 channels.
If divided and recorded, narrow band of Bw / 2 per channel
(The number of pixels per block is 1024/2 = 512
It will be possible to record with. This is applied to, for example, the above VTR.
In this way, the occupied band of the recording signal per channel can be narrowed.
Therefore, the recording density of the tape can be significantly reduced.
Size of the head drum, the number of heads used,
The number of channels is reduced to reduce the size, weight and cost of the device.
Can be revealed. An embodiment of the present invention will be described below with reference to FIG.
You. Figure 1 shows a wideband video signal divided into two channels.
Example of a rotary head type magnetic recording / reproducing apparatus for recording
Show. Video signals to be recorded include red (R) and green
(G) and blue (B) three primary color video signals
a, 1b, and 1c. These three primary color video signals
Matrix operation is performed appropriately by the encoder 10.
It is converted into a luminance signal Y0 and two color signals C01 and C02.
The luminance signal Y0 from this encoder 10 is a low-pass filter.
The bandwidth is appropriately limited according to the bandwidth required by the filter 11.
The luminance signal Y limited to the band Bw is
It is output from the filter 11. From the encoder 10
The two color signals C01 and C02 of
3 depending on each direction horizontal and vertical
Both are band limited. This vertical band limitation is
Conversion to a line-sequential system by a switching circuit 104 described later
To eliminate the vertical fold distortion caused by
It is valid. Here, both are limited to the band Bw / 2.
Whether the two color signals C1 and C2 are filters 12 and 13, respectively.
Output from A block 100 indicated by a broken line is the luminance signal described above.
Occupation of video signal consisting of signal Y and two color signals C1 and C2
Compress the band so that image quality is less likely to deteriorate, and
Make sure that the signal occupancy band does not become unbalanced between the channels.
A band compression circuit for dividing into two channels
You. The operation of the band compression circuit 100 is shown in FIG.
This will be described using a ring pattern. In FIG. 2, L1
, L2, L3, ... Indicate line numbers of the video signal,
(i) is an example of a sampling pattern for the luminance signal Y
(Ii) is a sampling pattern for the color signals C1 and C2.
An example of a turn is shown. The line indicated by the broken line in (ii) of FIG.
The fields L1 ', L2', L3 ', ...
Interlaced by 2: 1 interlaced scanning
Indicates a field. In this case, the luminance signal of FIG.
Even though there are fields that are interlaced,
It is omitted here. In FIG. 1, the output from the filter 11 is
The luminance signal Y in the occupied band Bw is the A / D conversion circuit 10
Sampling clock CR with period τ (τ in FIG. 2) at 1
It is sampled by Y and converted into a digital signal. here
Then, the frequency fs of this sampling clock CRY is
In order to prevent foldback distortion, the following formula must be satisfied.
However, this is a limitation of the present invention.
Not the case. 2 × Bw ≦ fs (= 1 / τ) (1) The sampling clock CRY is not shown.
Is included in the above video signal, or is included separately with it.
It is generated in synchronization with the input synchronization information. Reference numeral 103 denotes a memory including a RAM and the like.
Yes, of the outputs from the A / D conversion circuit 101,
The sample data corresponding to the pixel indicated by the circle in 2 (i) is bright.
Are sequentially written to I of the memory 103 as the frequency signal Y1.
Sample data corresponding to the pixel indicated by X in FIG. 2 (i)
Are sequentially written in II of the memory 103 as a luminance signal Y2.
You. In addition, in the example of the sampling pattern in FIG.
Pixels are extracted in each line of L1, L2, L3, L4, ...
On the other hand, the pixels marked with X are L1, L3, L5, ...
Every other line is extracted as follows. The pixel of each of these
Although not shown, writing to the memory 103 is performed by the above sampler.
With a write clock generated based on the Gclock CRY
The above-mentioned pixels are marked with the sampling clock
The period 2τ (frequency fs
Of the memory 103 based on the write clock CR1 of
It is written to I line by line. In addition, the pixel marked with × is
Cycle 2 in which the write clock CR1 is delayed by time τ
Based on τ (frequency fs / 2) write clock CR2
Every other line is written in II of the memory 103. From the above, the luminance signal Y is sampled with a period τ.
All pixels obtained by sampling with the ring clock CRY
First, half the pixels (pixels corresponding to the circles) are extracted.
Are sequentially written to I of the memory 103, and the remaining half
From the pixel, half of that pixel (pixel corresponding to x mark)
It is extracted and sequentially written in II of the memory 103. Hiding
The sample data for each pixel written by
The above-mentioned memo by the read clock generated based on the clock.
It is sequentially read by the printer 103. The frequency of this read clock
The wave number may be appropriately determined as necessary, and is not a limitation of the present invention.
Although not prime, here, the write clocks CR1 and C are used.
Read clocks CR1 'and C of the same frequency as R2, respectively
R2 'is generated. Read clock CR1 '(frequency fs
/ 2), the sample data is
It is sequentially read for each IN, and accordingly, the D / A conversion circuit 121
Of the luminance signal Y1 which is converted into an analog signal and output.
The band is Bw / 2, which is lower than the band Bw of the original luminance signal Y.
The output that has been band-compressed to 1/2 is the D / A conversion circuit 1 described above.
Obtained from 21. Similarly, the read clock CR2 '(frequency f
s / 2), the sample data from II of the memory 103
Data is sequentially read at intervals of every other line, and the data switching circuit 1
An analog signal is input from the D / A conversion circuit 122 via the terminal a of
The band of the luminance signal Y2 that is output after being converted into
It becomes Bw / 2, and the band pressure is halved compared to the original band.
The reduced output is obtained from the D / A conversion circuit 122. Reference numeral 104 is a line-sequential system for switching simultaneous color signals.
Is a switching circuit for obtaining the above-mentioned filters 12 and 13
Two color signals of occupied bandwidth Bw / 2 output from each
C1 and C2 are connected to terminals a and b of switching circuit 104, respectively.
It is supplied and alternately switched by the switching circuit 104 for each line.
And the color signal C1 is changed over the lines L1, L3, L5, ....
Is selected and output, and the lines L2, L4, L6, ...
The signal C2 is selectively output. Thus, in the switching circuit 104
The color signal C0 converted into the line-sequential system is supplied to the A / D conversion circuit 1
At 02, as shown in (ii) of FIG.
s / 4) sampling clock CRC sampled
Converted to digital signal. This sampling clock
The frequency of the CRC is not a limiting condition of the present invention, but here
Is set to fs / 4. 2 (i) from the A / D conversion circuit 102.
i) Pixel indicated by ◯ (or interlace indicated by broken line)
Corresponding to the pixel of the field)
The sample data is the sampling clock CRC
Writing cycle of period 4τ (frequency fs / 4) generated based on
Lock CR3 to line III of memory 103 line by line
It is written in sequence. The sump for each pixel written in this way
Data is generated based on the above write clock CR3.
For the read clock CR3 'with a period of 2τ (frequency fs / 2)
Sequentially every other line from III of memory 103
It is read and its output is output from the terminal b of the data switching circuit 110.
Is converted into an analog signal by the D / A conversion circuit 122 via
Be done. The data switching circuit 110 described above is used for the memory.
The luminance signal Y2 output from II of 103
The line sequential color signal C output from III of
This is a circuit for division multiplexing and outputting. 3a is
The luminance signal Y1 output from the circuit 121 is shown as follows: b
Is a luminance signal Y2 output from the circuit 122 in a time division manner.
And line-sequential color signals C1 and C2. First, the line L1 is read from the memory 103-I.
1H (H is a horizontal scan)
Cycle 110), the circuit 110 is connected to the terminal a side.
Then, the luminance signal Y of the line L1 is read from the memory 103-II.
2 is read out and output. During this period, the memory 103-
Reading III is stopped. Subsequently, the memory 103
-The luminance signal Y1 of the next line L2 is read from I and output.
During this 1H period, the circuit 110 is connected to the terminal b side.
It is connected and the color signal C is read from the memory 103-III.
Output from the memory 103-II during this period.
Is stopped. As is clear from the above description, the above
Line-sequential color signal C of occupied bandwidth Bw / 2 from the circuit 104 of
Is a sampling clock of frequency fs / 4 in the circuit 102.
Since it is sampled by Rock CRC, its occupied bandwidth is Bw
/ 4 compressed, written to memory and sampled
The signal was read from memory at twice the frequency fs / 2
Therefore, the color signal C output from the memory 103-III is
The occupied bandwidth is expanded to Bw / 2, and its time axis is 1 /
Compressed to 2. Therefore, the period of 1H (that is, the line
The period when the luminance signal Y1 of the input L2 is output from the circuit 121.
Between the above), the color signal of the line L1 is output from the circuit 122.
C1 is time-compressed to 1/2 and output, and continues.
Then, the color signal C2 of the next line L2 is halved on the time axis.
Is output. Since the above operation is repeated thereafter,
As shown in FIG. 3, from the circuit 121, the lines L1 and L
2, L3, ... Luminance signal Y (pixels thinned to 1/2)
1 is continuously output, and the line 122 from the circuit 122
L3, L5, ... Luminance signals (pixels thinned to 1/2)
Y2 and line-sequential color signal C are output alternately in time-divisional lines.
I will be forced. Also, each output from the circuits 121 and 122
Have an occupied bandwidth of Bw / 2. Thus, the circuit 1 of the band compression circuit 100.
The output from the reference numeral 21 (luminance signal Y1) is the recorded video processing circuit.
Frequency modulation after pre-emphasis at 31
(FM), and the rotary magnetic head is passed through the recording amplification circuit 33.
Of the channel 1 on the magnetic tape 3 by the terminals 51a and 51b.
The signals are sequentially recorded. Similarly, the band compression circuit 10
0 output from the circuit 122 (luminance time-division multiplexed)
The signal Y2 and the color signal C) are output by the recording video processing circuit 32.
Recording processing is appropriately performed similarly to the recording circuit 31, and the recording amplification circuit 34
Through the rotary magnetic heads 52a and 52b.
Channel 3 signals are sequentially recorded in channel 3. Here, the heads 51a and 51b are mutually
Concentric head drum (not shown) with the same azimuth
They are mounted on the circumference at an angle of 180 ° to each other.
The heads 52a and 52b also have the same azimuth.
(The head 51a, 51b has a different azimuth
)) On the concentric circumference of the head drum,
A step is formed at an angle and near the heads 51a and 51b.
Installed. The magnetic tape 3 is
Wrapped around the dead drum slightly more than 180 °
The magnetic heads 51a, 51b, 52a, 52b are contacted with each other.
You. Therefore, on the magnetic tape 3, as shown in FIG.
As shown, scanning by the head 51a of channel 1
Tracks T11, T13, T15, ...
By scanning the head 51b of the track 1
4, T16, ... Are formed, and T11, T1 are formed on each of these tracks.
2, T13, T14, T15, ...
The signal of channel 1 is recorded. Similarly, channel
Tracks T21, T2 by scanning the head 52a of the track 2
, T25, ... are formed and the head 52b of the channel 2 is formed.
, The tracks T22, T24, T26, ... Are formed.
And each track has T21, T22, T23, T24, T2
The signal of channel 2 shown in Fig. 3b is recorded in the order of 5, ...
Go away. Next, the operation during reproduction will be described. Up
Recording is done by dividing into multiple tracks on the magnetic tape 3
The generated signal is transmitted to the magnetic heads 51a, 51b, 52.
a and the same magnetic head 61a corresponding to 52b,
The same as that formed at the time of recording by 61b, 62a, and 62b.
The tracks are played sequentially. That is, the heads 61a and 61 of the channel 1 are
b, T11, T12, T from the channel 1 track
The signal of the above channel 1 alternates in the order of 13, T14, ...
Regenerated, amplified by regeneration amplifier circuit 43 and switched alternately
A continuous signal is output from this circuit 43.
Be done. The reproduction output signal from the circuit 43 is the reproduction video processing time.
De-emphasis after FM demodulation on path 41
Then, the luminance signal Y1 corresponding to a in FIG.
1 and is supplied to the A / D conversion circuit 201.
Similarly, by the heads 62a and 62b of channel 2,
From the track of channel 2 T21, T22, T23, T24,
In this order, the signals of channel 2 above are reproduced alternately,
Is it amplified by the reproduction amplifier circuit 44 and switched alternately?
In the same way as the circuit 41, the reproduction video processing circuit 42 reproduces
Raw processed and time-division multiplexed corresponding to FIG.
The luminance signal Y2 and the line-sequential color signal C are output from this circuit 42.
It is supplied to the A / D conversion circuit 202. The block 200 indicated by the broken line is the circuit 4 described above.
Channel 1 signal from channel 1 and channel from circuit 42
Information thinned out from the signal of channel 2 without being recorded or reproduced.
Recording / playback information that is close to it temporally or spatially
Interpolate and restore correctly based on time axis and band
It is a band expansion circuit for. This band expansion circuit 200
FIG. 5 is a waveform chart of each part showing the operation and the sampling of FIG.
This will be described using a pattern diagram. First out of the circuit 41
The applied luminance signal Y1 is filtered by the A / D conversion circuit 201.
Sampling clock CPY of period 2τ (frequency fs / 2)
Corresponding to the pixel indicated by the circle in FIG. 2 (i).
The sample data is stored in I of the memory 203,
Writing the frequency fs / 2 generated based on the clock GCP CPY
Only the clock CP1 allows L1, L2, L3,
It is written in order of L4, ... On the other hand, the time division output from the circuit 42
The luminance signal Y2 and the color signal C are input to the A / D conversion circuit 202.
Sampling clock with a period of 2τ (frequency fs / 2)
Period when the luminance signal Y2 is input by sampling with CPC
In between, it is generated based on the above sampling clock CPC.
With the write clock CP2 having the frequency fs / 2,
The circuit 202 corresponding to the pixel indicated by the X mark in FIG.
The sample data from is written in II of the memory 203,
During this period, writing data to III of memory 203 is prohibited.
Be stopped. Next, in the period when the color signal C is input,
Frequency fs generated based on sampling clock CPC
By the write clock CP3 of / 2, as shown in FIG.
O (or X for fields indicated by broken lines)
The sample data from the circuit 202 corresponding to the pixel indicated by
Data is written to the memory 203-III,
Data writing to the memory 203-II is prohibited. others
Therefore, only the luminance signal Y2 is extracted to the memory 203-II.
Is written and written in the memory 203-III.
Only No. C is extracted and written. Reference numeral 211 is for performing pixel interpolation of the luminance signal Y.
Is a Y-interpolation circuit, and 212 is an image of the line-sequential color signal C
It is a C interpolation circuit for performing elementary interpolation and converting into a simultaneous expression.
You. Luminance signal written in the memory 203-I.
No. Y1 is a read clock with a period of 2τ (frequency fs / 2).
It is read line by line by CP1 'and is shown in Fig. 5a.
As described above, the luminance signal Y1 of each line is L1, L2, L3.
, L4, L5, ...
11 is supplied to one side. Write to the above memory 203-II
The luminance signal Y2 thus obtained has a period of 2τ (frequency fs / 2).
Repeated twice per line with read clock CP2 '
As a result of reading, as shown in FIG.
The luminance signal is continuous for two lines L1, L1, L3, L3,
L5, L5, ...
Is supplied to the other. In this Y interpolation circuit 211,
Luminance signal Y1 from the memory 203-I (a in FIG. 5)
And the luminance signal Y2 from the memory 203-II (see FIG. 5).
b) and are alternately selected and extracted for each period τ from FIG.
As shown in C, the combined luminance signal Y'is output.
Is done. Of the luminance signal Y ', lines L1, L3,
Luminance signals Y11, Y33, Y55, which are output as L5, ...
Is the luminance signal Y1 of the original lines L1, L3, L5, ....
The luminance signal of the same line as (the pixel indicated by the circle in FIG. 2 (i))
No. Y2 (pixels indicated by x in FIG. 2 (i)) are at time τ
The original luminance information Y is restored correctly because it is synthesized with a shift.
Be done. On the other hand, the lines L2, L4, L6, ...
The applied luminance signals Y21, Y43, Y65, ... are the original lines.
Luminance signals Y1 of L2, L4, L6, ... (O in FIG. 2 (i)
Mark pixel) and the brightness of the lines L1, L3, L5, ... In front of it
The frequency signal Y2 (pixels marked with X in FIG. 2 (i)) are mutually time τ
Synthesized by shifting. That is, it is not transmitted without being recorded and reproduced.
It was wrong (empty lines L2, L4, L6, ... in Fig. 2 (i).
Luminance pixel information (shown in white) is recorded, reproduced, and transmitted (Fig.
2 (i) lines L1, L3, L5, ...
The original luminance information is close to the
Restored similarly. Generally, image information has a strong correlation between lines.
Since it is related, the image of pixel thinning by the above interpolation is
The impact on quality can be greatly improved. D / A conversion output from the circuit 211
Brightness converted into an analog signal and output by the circuit 221
The frequency signal Y ′ is obtained by the above-mentioned pixel interpolation by the above-mentioned filter.
The same occupied band Bw as the original luminance signal Y which is the output of 11
Have. Next, the data is written in the memory 203-III.
The line-sequential color signal C has a period of 4τ (frequency fs / 4)
Are sequentially read by the read clock CP3 '. As above
As described above, the writing to the memory 203-III has the frequency fs /
2 is performed by the write clock CP3, while read is performed.
The read clock C has a frequency fs / 4 that is half of the read clock C.
Since it is performed by P3 ', the time axis is 2 for writing and reading.
Doubled and, as shown in FIG. 5d, lines L1 and L
In 3, L5, ..., The color signal C1 is the lines L2, L4, L
6, the color signal C2 is line-ordered with the original regular time axis.
It is output by the following formula. Output from this memory 203-III
The line-sequential color signal C is supplied to the pixel by the C interpolation circuit 212.
Interpolated and the line-sequential formula is converted to the simultaneous formula, the simultaneous formula 2
Two color signals Ca1 and Ca2 are output from this circuit 212.
You. Pixel interpolation in this C interpolation circuit 212
The color signal C from the memory 203-III which is input is line-ordered.
Since it is the following formula, two lines before in the same field
Interpolates with signals of similar colors after two lines, or
One field before or one field after (or one frame
Interpolation with similar color signal of line before frame or after 1 frame)
Should be done. Here, the latter one field before
The operation when performing interpolation with the color signal
To do. In the C interpolation circuit 212, the memory 2
The color signal C from 03-III (d in FIG. 5) is at least
Consists of a memory that stores color information for one field
One field is delayed by the field delay circuit.
The output from this field delay circuit is shown in FIG. Output signal C from the memory 203-III
(D in FIG. 5) is a line L1 shown by the solid line in FIG.
L2, L3, ...
Then, the output signal C ′ from the field delay circuit (see FIG.
E) indicates the field one field before indicated by the broken line in FIG. 2 (ii).
Including color pixel information indicated by x marks of L1 ', L2', L3 '
No. From the two color signals C and C ′, the period 2τ
5 are alternately selected and extracted for each pixel, and as shown in FIG.
As described above, the combined color signal Ca is output. Further
Specifically, the color signals C1 of the lines L1, L3, L5, ...
The same as the lines L1 ', L3', L5 ', ... one field before.
The color signals C1 of system colors are interpolated, and the lines L1, L3, L5
, Are output as color signals C11, C33, C55, ...
You. Further, the color signals C2 of the lines L2, L4, L6, ...
The same as the lines L2 ', L4', L6 ', ... one field before.
The color signals C2 of system colors are interpolated, and the lines L2, L4, L
Are output as color signals C22, C44, C66, ...
You. Therefore, this output Ca (f in FIG. 5) is a line-sequential color.
Pixels that are signals and that were not recorded / played back and transmitted were
Since it is interpolated as described below, its occupied band is Bw / 2.
It will be restored to its original state. The output Ca is further supplied to the C interpolation circuit 212.
Then, as shown in g and h of FIG. 5, two signals Ca1 and C1
It is divided into a2. One signal Ca1 (g in FIG. 5) is
From the line-sequential color signal Ca (f in FIG. 5), the lines L1 and L
Extracting the color signals C11, C33, C55, ... Of 3, L5 ,.
By outputting two lines continuously, in other words, the line is output.
Color signals of L2, L4, L6, ...
By interpolating with the previous color signals C11, C33, C55, ...
can get. Similarly, the other signal Ca2 (h in FIG. 5)
Is a line from the line-sequential color signal Ca (f in FIG. 5).
Color signals C22, C44, C66, ... Of L2, L4, L6, ...
In other words, by extracting and outputting continuously for two lines
Then, the color signals of the lines L1, L3, L5, ...
Interpolation with the color signals C22, C44, C66, ... One line before
It is obtained by Thus, the line-sequential color signal Ca is
Converted to two simultaneous color signals Ca1 and Ca2,
The analog signals are supplied to the D / A conversion circuits 222 and 223.
Is converted into a number. Band restoration by the above band expansion circuit 200
From the D / A conversion circuits 221, 222, 223
The luminance signal Y ′ and the color signals Ca1 and Ca2 which are the outputs of
Unnecessary signals in the low-pass filters 21, 22, and 23, respectively
After the components are removed, the decoder circuit 20
Of the original 3 primary color signals
The corresponding red (R), green (G), and blue (B) primary color signals are
It is output to the output terminals 2a, 2b and 2c, respectively. Incidentally, the A / D conversion circuits 201 and 202
Sampling clock CPY supplied to each
And CPC are output from the circuits 41 and 42, respectively.
The synchronization information contained in the signals of channels 1 and 2
Are generated synchronously. In addition, the above-mentioned read clock C
P1 ', CP2', and CP3 'are not crystal oscillator circuits, though not shown.
It is generated based on the stable internal reference clock obtained. As described above, in the embodiment of FIG.
The line-sequential color signal C0 of the band Bw / 2 output from the above
Sampler with period 4τ (frequency fs / 4) in circuit 102
If the pixel is thinned by sampling with the ing clock CRC
However, the frequency of this sampling clock CRC
Number f _CP Is the horizontal scanning frequency f of the video signal _H For n
As a number, 1/4 to 3/4 as shown in the following equation (2)
Line-sequential color signal
Interpolation of pixels thinned out from C0 is performed in the same field.
It can be performed with little quality deterioration. F _CP = (N + (1/4)) × f _H Or f _CP = (N + (3/4)) × f _H (2) Sampling clock CRC represented by the equation (2)
Sampling pattern for line-sequential color signal C0
Is shown in FIG. In the figure, lines L1, L3, L5, ...
The pixel indicated by the circle is one of the colors of the line-sequential color signal C0.
The sampling pixels for the signal C1 are shown, and the lines L2 and L4 are shown.
, L6, ... Pixels indicated by ● correspond to the other color signal C2.
Sampling pixels to be displayed. As is clear from FIG.
And the sampling clock C given by the above equation (2)
The sampling phase of RC becomes in-phase in 4 line periods and becomes horizontal.
Aligned in the same direction, the pixels are in opposite phase in the 2-line cycle
Thinned out. On the other hand, since the color signal C0 is a line-sequential type, it has two lines.
Signals of similar colors (C1 to C2) are repeated every
Therefore, as shown in FIG. 6, the color signal C1 of the line L1
The line L3, which is two lines after the sampling pixel a, is of the same system.
Same as pixel a above line L3, including color signal C1
The phase pixel a'is thinned out without being sampled. Similarly,
For the sampling pixel b of the color signal C2 on the line L2, 2 lines
After that, line L4 contains signal C2 of similar color,
The pixel b'of the same phase as the pixel b on L2 is sampled
Without being thinned out. Pixels a ′ (not present) thinned out in this way
B ′) is as indicated by the arrow in FIG. 6 in the circuit 200.
Are closest to the same field in the same field and have the same color and phase (
The pixel a (or b) recorded and reproduced is interpolated. In this way, the same temporally and spatially close
Pixel interpolation is performed with a signal having a strong correlation of system colors, and
It is possible to minimize image quality deterioration due to thinning. It should be noted that, in the above embodiment, the pixel for the color signal is
Although the case where interpolation is performed is shown, the present invention is not limited to this.
Generally, the human eye does not have enough resolution for color.
Since it does not have the capacity,
Either one of the two color signals C01 and C02 from 0 is absent
Further band limit both of them (eg to Bw / 4)
Therefore, the pixel interpolation as described above may not be performed,
It can be put to practical use. Note that such band control of color signals
The bandwidth margin of the recording signal generated by the
It is also possible to assign them, one example of which is shown in FIG.
You In the figure, a is the luminance recorded as the signal of channel 1.
The signal Y1 is shown, and b is recorded as a channel 2 signal.
Luminance signal Y2 'and line-sequential color signals C1', C2. Two color signals C01 and C from the circuit 10
One of the two, C01, is a band Bw / 8 in the above filter 12.
And the time axis of the circuit 100 is 1/4.
To the color signal C1 '(of FIG. 7b)
It is recorded as C1 '). The other color signal C02 is the above
Is limited to the same band Bw / 2 as before by filter 13 and
Pixel thinning is performed in the same manner as described above in the circuit 100.
Further, the time axis is compressed to 1/2 and the occupied bandwidth Bw /
Two color signals C2 (C2 in FIG. 7b) are recorded. So
As a result, the line-sequential color signals C1 'and C2 are (3 /
4) It is possible to record at H, and the line sequential color signals C1 and C2 are 2 lines.
Compared to the previous embodiment shown in FIG. 3 in which 1H is recorded for each time,
In between, a redundant period of (1/4) H is obtained for two lines.
It is possible to record extra luminance information in this redundant period.
2 lines, as shown in FIG. 7b, for example.
Band (Bw / 2) similar to the above during the period of (5/4) H
To record as a signal Y2 'containing more luminance information.
You can As described above, the present invention is based on the image to be recorded.
The brightness information of the image signal is divided into 1/2 pixel group and 1/4 pixel group.
Separate and record on the first and second channels separately
The pixel group can be divided arbitrarily.
Is. In FIG. 2 (i), a pixel marked with a circle is a half image.
It records in the 1st channel as a prime group, and the pixel of X mark is 1 /
Example of recording on the second channel as a 4-pixel group
Is. Another embodiment of the present invention described above is illustrated.
8 shows. 8 (i) and (ii) are both luminance signals.
The sampling pattern for No. Y is shown,
Is recorded in the first channel as a 1/2 pixel group,
Pixel is a 1/4 pixel group together with color information not shown.
It is recorded on the second channel by time division. (I) in the figure
Are sampling pixels from the lines L1, L3, L5, ...
All are extracted and recorded as a channel 1 signal.
, L2, L4, L6, ...
Example of outputting and recording as channel 2 signal
Indicates. (Ii) uniformly extract pixels from each line
This is an example of the case of performing the sampling pixel of each line.
Then, thin out every other pixel and extract (pixels marked with a circle)
It is recorded as the signal of channel 1 and the pixel different from this is recorded.
Channels are extracted by thinning out every third (pixels marked with ×)
An example of recording as a 2 signal will be described. Next, the embodiment shown in FIG. 3 and FIG.
In both cases, one channel (channel 1)
One screen extracted from video information (one field or one
1/2 the first luminance information per frame) (that is, the above figure)
2 (i) and (i) and (ii) of FIG.
Luminance information corresponding to the pixel of the mark) Y1 is recorded, and the other
The rest of the original video information on the channel (channel 2)
2nd luminance information of 1/4 per one screen (that is, FIG.
(I) and the x marks shown in (i) and (ii) of FIG. 8 above.
Luminance information corresponding to a pixel) Y2 and two types of color information C1,
The case where C2 is recorded by time division multiplexing has been shown.
Is not limited to this.
Channel (two channels in the above embodiment) to each other.
The above two types of brightness are
Degree information Y1 and Y2, and the above two types of color information C1 and C2
May be mixed and recorded, and the gist of the present invention
Does not deviate. One example is shown in FIG.
The operation will be described with reference to the waveform chart of 10. In FIG.
And a is the luminance information (Y1, Y2) and the color information (C
The original video signal V including 1 and C2 is supplied for four line periods (line
L1, L2, L3, L4 for 4H period)
It is a waveform diagram. This original video signal V has a period of 4 lines.
The band compression circuit 100 ′ shown in FIG.
Video signal V1 of channel 1 (b in FIG. 10) and channel 2
Image signal V2 (c in FIG. 10). In FIG. 9, the band compression circuit 100 'is not shown.
It is almost common to the band compression circuit 100 shown in FIG.
The same symbols are used for the common parts, and the operation of the common parts is
Since it is the same as FIG. 1 described above, detailed description will be omitted. This band
In the compression circuit 100 ′, I
The degree information Y1 is written, and the above luminance is stored in II of the memory 103.
Information Y2 is written, and the above is written in III of the memory 103.
The point that the color information C1 and C2 are written line-sequentially is as shown in FIG.
It is the same, but reading from these memory 103 is basically
Cyclic in units of 4 lines with period T0 (T0 shown in FIG. 10)
1 is different from that in FIG. 1 described above. In the embodiment of FIG. 10, the configuration of FIG.
Based on the sampling pattern shown in (i),
The frequency signal Y is sampled and written in I and II of the memory 103.
Get caught. That is, the brightness from the filter 11 shown in FIG.
The signal Y is the A / D conversion signal of the band compression circuit 100 'shown in FIG.
Is supplied to the conversion circuit 101 and converted into a digital signal,
The output is alternated to I and II of the memory 103 for each line.
Written in. Odd-numbered lines shown in FIG. 8 (i)
For L1, L3, L5, L7 ...
This pixel (as described above, of the effective part of the original image information,
(Equivalent to 1/2 effective pixels per field)
By writing clock of frequency fs to I of memory 103
Sequentially written. In addition, even-numbered lines L2, L4,
For L6, L8, ... Sampling pixels (original
Of the effective part of the video information, 1/4 per field
Frequency corresponding to II in the memory 103
It is sequentially written by the write clock of fs / 2. From the filters 12 and 13 of FIG.
The output color signals C1 and C2 are output to the switching circuit 10 of FIG.
4 is converted into a line-sequential color signal C0, and its output C0 is
Converted to a digital signal by the A / D conversion circuit 102
And then write frequency fs / 4 to III of memory 103
It is sequentially written line by line by the clock. Next, the data is written in I of the memory 103.
Brightness of the odd-numbered lines L1, L3, L5, L7, ...
Degree information Y1 is based on the read clock of frequency fs / 2
It is read sequentially, so its time axis is doubled and
The line period is output as a signal of T1 (= 2H)
You. The output from I of the memory 103 is the dividing circuit 11
At 1, the signal is divided into two signals alternately line by line.
Output to terminals 1 and 2, respectively. Therefore, the above terminal 1
Et al., As shown in b of FIG.
Every 2T1 = 4H) in the order of lines L1, L5, L9, ...
Then, the luminance information Y1 is output, and (T0 −
A time gap of T1) is produced. Similarly, from terminal 2 above,
As shown in c of FIG.
The luminance information Y1 is output in the order of in L3, L7, L11, ....
The time gap between each line is (T0-T1)
Cause Shaped by the output of the above odd-numbered lines
Time gap between each line above (T0-T1)
The signals written in II and III of the memory 103 are
The signals from these II and III are divided so that they can be output separately.
Reading is controlled. That is, it is written in II of the memory 103.
The brightness of the even-numbered lines L2, L4, L6, L8, ...
Information Y2 is read by the read clock of frequency fs / 2.
It is read next time, so the time axis is not expanded and one line
Is output as a signal of T2 (= 1H). This
The output from II of the memory 103 is sent to the division circuit 111.
Are divided into two signals alternately on a line-by-line basis.
Following the output of the luminance information Y1 from the terminals 1 and 2
Output in time division. In addition, to III of the memory 103
The written line-sequential color information C1 and C2 is the frequency.
read sequentially with a read clock of fs / 2, and
The time axis is compressed to 1/2 and the period of one line is T3.
(= 0.5H) signal (C1) and T4 (= 0.5H)
It is output line-sequentially as a signal (C2). This memory 1
The output from III of 03 is divided into two lines by the dividing circuit 111.
Are alternately divided into two signals, and
The output of the luminance information Y2 from the children 1 and 2 is followed by time division.
Is output. Thus, the terminal 1 of the division circuit 111 and
From 2 onward, as shown in b and c of FIG.
The above-mentioned luminance information Y1 of T1 and the above-mentioned luminance of T2
Information Y2 and T3 above color information C1 and T4 above color information C
2 is time-division-multiplexed so that the basic period T0 (= T1 + T2 + T
It is output at 3 + T4). The output from the terminal 1 is the D / A conversion circuit 1
Signal of channel 1 converted to analog signal at 21
V1 is output, and this output V1 is the recorded image of FIG.
It is supplied to the image processing circuit 31. Similarly, the output from the terminal 2 is D / A converted.
Channel converted to analog signal by conversion circuit 122
2 is output as signal V2, and this output V2 is shown in FIG.
Is supplied to the recorded image processing circuit 32. Both of the above two outputs V1 and V2 are occupied
It goes without saying that the band is Bw / 2. In addition, above
The signal V1 is shown in FIG. 4 as the signal of channel 1.
On the channel 1 track (T11, T12, T13, ...)
The recorded signal V2 is recorded as a channel 2 signal.
Recorded on the channel 2 (T21, T22, T23, ...)
However, the recording position is perpendicular to the longitudinal direction of each track.
In the same direction, the signals V1 and V2
In order to align each basic period T0 with the above,
The dividing circuit 111 in FIG. 9 outputs the above V1 and V2.
Imming is controlled. FIG. 11 is based on the above in connection with the present invention.
An example of a track pattern to be recorded and formed will be shown. As described above, each channel is recorded between adjacent tracks.
The channel signals V1 and V2 are
Since it is aligned in the vertical direction of the rack, it can be regenerated.
Sometimes a tracking error occurs and the
Even if there is stalk, the crosstalk signal will
Since it has a very strong correlation with the playback signal from the
For example, if the reproduction signal from the own track is Y1, the adjacent track
Y1 component with strong correlation in the crosstalk signal from the clock
Therefore, the interference caused by the crosstalk signal is
It has the effect of becoming zero beat and visually reducing the interference.
can get. The samples shown in FIG. 2, FIG. 6 and FIG.
Both the vertical pixels and the horizontal blanking period
Effective pixels in the effective period of video information excluding the king period
Shows the vertical blanking period and horizontal
Sampling pixels in the sampling period along with the effective pixels
Even if the data is apportioned and recorded on the channels, it falls within the scope of the present invention.
Needless to say. In addition, each blanking period above
Separate synchronization information (vertical synchronization signal, horizontal synchronization signal or predetermined
Such as burst signals that repeat multiple cycles at a frequency)
In the case of recording arbitrary information in a multiplexed manner,
Of the blanking information and time-division multiple
Even in the case of overlapping recording, it falls within the scope of the present invention,
The same effect can be obtained in any of these cases.
You. Particularly, the vertical blanking period and the horizontal blanking period are
Delete all or part of the ranking period
If you do, the blanking period will be deleted.
In order to eliminate the time gap caused by
Time of report Y1 and Y2 and the above two types of color information C1 and C2
The axis can be stretched and recorded, and thus its time axis
The occupied band of the recording signal can be further narrowed according to the extension amount.
It is possible to improve the S / N ratio of the reproduced signal or for a longer time.
The effect that it becomes possible to record for a while is obtained. In FIG. 3, FIG. 5, FIG. 7, FIG.
In each waveform diagram, only luminance information and color information are shown.
Without vertical blanking or horizontal blanking.
Blanking information and sync information such as vertical sync and horizontal sync
Are omitted, but the present invention is impaired by the above-mentioned gist.
Not a thing. Also, as mentioned above, vertical blanking
Remove all or part of the period and horizontal blanking
Delete the blanking period and delete the blanking period.
For each line to eliminate the time gap caused by
Since the time axis extension is performed, one line shown in FIGS.
The in period becomes longer than 1H, and the other FIG.
The same applies to FIG. 11. As described above, according to the present invention, a wide range is provided.
The band video signal can be band-compressed with little deterioration in image quality. Only
However, multiple channels are used so that the occupied bandwidth of the signal is almost even.
Channels can be recorded separately by dividing them into channels.
The recording signal band per unit is efficiently reduced without excess or deficiency,
Therefore, in a magnetic recording / reproducing apparatus such as a VTR,
It is possible to record and reproduce wideband video signals using RAM.
Therefore, it is possible to reduce the size and weight of the device, and
Since the number of channels used can be reduced, the circuit scale can be reduced.
It is possible to reduce the size of the device and reduce the cost of the device.
It is possible to obtain the effect that recording can be performed for a long time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a magnetic recording / reproducing apparatus showing one embodiment of the present invention. FIG. 2 is a schematic diagram of a sampling pattern according to the present invention. FIG. 3 is a signal array diagram showing an example of a recording signal waveform. FIG. 4 is a schematic diagram of a track pattern of a tape. 5 is a signal array diagram showing waveforms of respective parts of FIG. FIG. 6 is a schematic diagram showing another example of a sampling pattern. FIG. 7 is a signal array diagram showing another example of a recording signal waveform. FIG. 8 is a schematic diagram showing another example of a sampling pattern. FIG. 9 is a block diagram showing another embodiment of the band compression circuit according to the present invention. FIG. 10 is a signal array diagram showing waveforms at various points in FIG. FIG. 11 is a signal array diagram showing another embodiment of the track pattern. [Description of Reference Signs] 100 ... Band compression circuit, 104 ... Switching circuit, 103 ... Memory, 110 ... Data switching circuit, 101, 102, 201, 202 ... A / D conversion circuit, 121, 122, 221, 222, 223 ... D / A conversion circuit, 200 ... Band expansion circuit, 211 ... Y interpolation circuit, 212 ... C interpolation circuit.

   ────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fumio Okamura               292 Yoshida-cho, Totsuka-ku, Yokohama-shi Co., Ltd.               Home Appliance Research Laboratory, Hitachi, Ltd.                (56) References JP-A-60-94591 (JP, A)                 JP 61-62290 (JP, A)                 JP 57-210789 (JP, A)

Claims (1)

(57) [Claims] 1. In a device configured to reproduce a medium in which a video signal including luminance information and two pieces of first and second color information is recorded in a prescribed number of channels, the luminance information is provided in a prescribed block including a plurality of pixels. Each of the at least two first group luminance signals (Y1) and second group luminance signals (Y1) having different processed information amounts after being sampled at a predetermined frequency to reduce or compress the original information amount of each block A luminance signal including a luminance signal (Y2) and each of the first and second color information are sampled at a frequency lower than the sampling frequency of the luminance information for each predetermined block including a plurality of pixels, A first group of color signals (C1) based on the first color information having a processed information amount after reducing or compressing the original information amount of each block and a second group based on the second color information. Color signal (C2) of Reproducing means for reproducing the medium in which the color signals including the time-division multiplexed signals are recorded, which are time-divided and multiplexed so that the transmission amount per unit time recorded in each of the channels is substantially constant. And the luminance signal contained therein is separated from the reproduced time division multiplexed signal from the reproducing means, and at least the first group or the second group in which the amount of information is reduced or compressed.
Supplementing the processed information content of either of the group luminance signals,
First color conversion means for converting into a luminance information signal having substantially the same information amount as the original information amount of the luminance information, and the color signal contained therein from the time division multiplexed signal reproduced from the reproducing means. By separating and at least supplementing the processed information amount of the color signals of the first group or the second group, in which the information amount is reduced or compressed, an information amount which is almost the same as the original information amount of the color information is obtained. And second output means for outputting the luminance information signal from the first conversion means and the color information signal from the second conversion means. An apparatus for reproducing a video signal, characterized in that 2. In a device configured to reproduce a medium in which a video signal including luminance information and two pieces of first and second color information is recorded in a prescribed number of channels, the luminance information is provided in a prescribed block including a plurality of pixels. Each of the at least two first group luminance signals (Y1) and second group luminance signals (Y1) having different processed information amounts after being sampled at a predetermined frequency to reduce or compress the original information amount of each block A luminance signal including a luminance signal (Y2) and each of the first and second color information are thinned out at least in a field of the video signal by an information amount corresponding to an information amount in scanning line units by line sequential processing. And converting into a line-sequential signal having an information amount reduced to at least ½ of the original information amount per field, and converting the line-sequential signal based on each of the first and second color information. each Is sampled at a frequency lower than the sampling frequency of the luminance information for each predetermined block including a plurality of pixels, and the first information having the processed information amount after reducing or compressing the original information amount of each block A color signal including a first group of color signals (C1) based on the first color information and a second group of color signals (C2) based on the second color information, for each channel, Recording means for reproducing the medium on which the time-division multiplexed signal is recorded so as to apportion the time occupied by the recording by a ratio based on the processed information amount of each, and the reproduction means. The luminance signal included in the time-division multiplexed signal is separated from the time-division multiplexed signal, and at least the amount of information is reduced or compressed.
Supplementing the processed information content of either of the group luminance signals,
First color conversion means for converting into a luminance information signal having substantially the same information amount as the original information amount of the luminance information, and the color signal contained therein from the time division multiplexed signal reproduced from the reproducing means. By separating and at least supplementing the processed information amount of the color signals of the first group or the second group, in which the information amount is reduced or compressed, an information amount which is almost the same as the original information amount of the color information is obtained. And second output means for outputting the luminance information signal from the first conversion means and the color information signal from the second conversion means. An apparatus for reproducing a video signal, characterized in that 3. The first conversion means outputs the processed information amount of either the first group or the second group of luminance signals whose information amount has been reduced or compressed at least in the same field of each block. 3. The video signal reproducing apparatus according to claim 2, further comprising means for supplementing with a signal of a block of a field before or after the field. 4. The second conversion means outputs the processed information amount of at least the color signal of the first group or the second group, which has been reduced or compressed, in the same field of each block or at least 1. 3. The video signal reproducing apparatus according to claim 2, further comprising means for supplementing with a signal of a block of a field before or after the field.