JPS62254593A - Picture signal processor - Google Patents

Abstract

PURPOSE:To remove the deterioration in a picture quality and to attain the high picture quality by time division multiplexing a chrominance signal and a brightness high frequency component extracted at one horizontal scanning line interval and synthesizing with a brightness low frequency component. CONSTITUTION:A luminance signal Y by a sequential scanning is separated into a high frequency component YH in a HPFS (high pass filter) 9 and into low frequency component YL in a subtraction circuit 10. The brightness high frequency component YH is delayed by 1H in a 1H delay line 12 and every 2H of the high frequency luminance signal YH of a horizontal scanning line at 1H interval is successively outputted from a switch 13. The chominance signal C obtains the time division multiplex signal YH/C of the brightness high frequency component YH and the chrominance signal C by alternately changing over the brightness high frequency component YH from the switch and the brightness high frequency component YH and the chrominance signal C at every 2H by a switch 27. The brightness low frequency component YL outputted from the subtracter 10 is supplied to an adder 29 and added to the time division multiplex signal YH/C. A synthesizing signal is converted into the synthesizing signal by a jumping scanning in an exchange 30, consists of the brightness low frequency signal YL in a low frequency area and a signal formed by alternately multiplexing the brightness high frequency signal YH and the chrominance signal C at every 1H is obtained in the high frequency area.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image signal processing device that is compatible with current standard broadcasting systems and that is capable of obtaining high-quality reproduced images.

[Conventional technology]

Current standard broadcasting system (NTSC system in Japan, the United States, etc.)
In Europe and other countries, PAL and SgCAM systems]
Interlaced scanning is performed from the video camera to the receiver. This interlaced scan.

One screen (i.e., one frame) has two fields,
The field of nest 2 scans between the portions of the scanning plane scanned by the first field, and the transmission frequency band of the image signal is narrowed to enable high-quality image transmission.

On the other hand, in recent years, there has been a desire to further improve the reproduced image quality, and 11th-order scanning has been attracting attention as one method for achieving this. This is a method in which the scanning plane is scanned sequentially, and an image signal for one screen is obtained by scanning the entire scanning plane once. Therefore, the scanning plane is repeatedly scanned at the same position. . According to this sequential scanning, when the number of horizontal scanning lines in one image is equal compared to the case using interlaced scanning, the transmission frequency band increases, but the image quality of the reproduced image is significantly reduced. When adopted as a broadcasting system, it is necessary to be able to receive image signals based on this system with a conventional receiver based on the current standard broadcasting system and reproduce the image. Conversely, a television receiver based on this progressive scanning broadcasting system also needs to be able to receive 1-all image signals according to the current standard broadcasting system and reproduce a single image.

Conventionally, one way to ensure compatibility between both methods is to
The paper ``About Eye Vision'' by Hiroshi Shibata et al. was reported in the Technical Report of the Television Society of Japan, published on October 21, 1985, TEBS 106-4 pp, 19-23. In this method, an image signal is obtained by sequentially scanning 525 scanning lines per image and 30 images per second (frame frequency 30 Hz) in a television camera, and this image signal is subjected to interlaced scanning at a field frequency of 60 Hz and a frame frequency of 30 H2. Convert it to an image signal and send it,
On the receiving side, the received image signal is converted back into a sequentially scanned image signal using a frame memory and displayed.

According to this method, there is no interlacing and only 111 vertical solutions! The image quality is greatly improved and excellent image quality can be obtained. Furthermore, when the receiving side receives an image signal based on the current standard broadcasting system, this image signal can also be converted into an image signal based on sequential scanning and displayed. Since the image signal is converted into a scanned image signal and transmitted, it can be received and reproduced even by a conventional television receiver according to the current standard broadcasting system.

[Problem that the invention seeks to solve]

By the way, in the prior art described in the above paper, the color signal is frequency-multiplexed with the luminance signal and transmitted, similar to the NTSC system. In the current standard broadcasting system, the frequency band of the luminance signal is restricted to greatly prevent mutual interference between the luminance signal and chrominance signal, that is, cross color and dot interference. However, it is not possible to limit the frequency band of the luminance signal from above, and if the frequency of the luminance signal and color signal is multiplied by 1, 1 color erasure is within the frequency band of the luminance signal (
(high frequency side). For this reason, there is a problem in that cross color and dot interference appear conspicuously. In other words, dots flow at the edges of the image, and cross-colors cause the screen to flicker in the finer details of the image), resulting in frequent problems in that the sequential scanning method cannot reproduce the calm images that should originally be produced.

The purpose of the present invention is to solve the problems of the prior art, ensure compatibility with the current standard broadcasting system, and generate an image signal by interlaced scanning that does not cause cross color or dot interference from an image signal by sequential scanning. An object of the present invention is to provide an image signal processing device capable of processing images.

[Means for solving problems]

In order to achieve the above object, the present invention divides a luminance signal by sequential scanning into a luminance high-frequency component and a luminance low-frequency component in the same frequency band as a color signal, and divides the luminance high-frequency component into one.
Extract every other horizontal scanning line, and extract two color difference signals every other horizontal scanning line, modulate them, and add them to form a color signal, and extract this color signal and every other horizontal scanning line. The high-frequency luminance component thus obtained is time-division multiplexed and combined with the low-luminance component, and this composite signal undergoes signal conversion to become an image signal by interlaced scanning.

[Effect]

The frequency bands of the luminance signal and the chrominance signal do not overlap at the same time, and the luminance signal and the chrominance signal can be completely separated by a simple selection means, and no cross color or dot interference occurs in the reproduced image.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is a block diagram showing an embodiment of an image signal processing device according to the present invention, in which 1 to 7 are input terminals, 8 is an output terminal, 9 is an HPF (bypass filter), 10 is a subtracter, and 11 is an output terminal. is a vertical LPF C low-pass filter), 12 is a 1H delay line (however, IH is one horizontal scanning period in sequential scanning), 15 is a switch, 14 is a 172 frequency divider, 15 is a vertical LPF, 16 is a 1H delay line, 17 is a switch, 1B is a multiplier, 19 is a BPF (band pass filter), 20 is a vertical LPF 121 is a 1H delay line, 22 is a switch, 23 is a multiplier, 24 is a BPF%, 25 is an adder, 26 is 172
27 is a switch, 28 is a delay line, 29 is an adder, 60 is a converter, and 51 is an adder.

In the figure, a luminance signal Y obtained by sequential scanning is inputted from an input terminal 1. This luminance signal Y is supplied to HPF'9, and the luminance signal Y corresponding to the frequency band on which the color signal is multiplexed is
A high frequency component (hereinafter referred to as a luminance high frequency component) C'ht) is separated. This brightness high-frequency component Ya is supplied to the subtraction circuit 10, where the brightness high-frequency component Ym is removed from the brightness signal Y from the input terminal 1, resulting in a low-frequency component (hereinafter referred to as a brightness low-frequency component) CYr of the brightness signal Y. ) is obtained. Also, HPF9
The brightness high frequency component Ym obtained in is supplied to the vertical LPF 11 to limit the frequency band in the vertical direction. This vertically band-limited high-frequency luminance signal YH is input directly to the switch 13 on the one hand, and is delayed by 1H with a 1H delay @12 and input to the switch 13 on the other hand.

- 10,000, a horizontal synchronizing pulse H8 for sequential scanning is input from the input terminal 4, and this horizontal synchronizing pulse H8 is divided by 172 by the 2-frequency divider 14, and the switch 13 is set to 1H by this pulse. The luminance high-frequency signal Yi from the vertical LPI' 11 and the luminance high-frequency signal Yg from the 1H delay line 12
Switch between. Therefore, the switch 13 successively outputs the high frequency emission signal YII of the horizontal scanning line every 1H, 2H each. That is, if the luminance high-frequency component Ym of the first horizontal scanning line is Ym, sy/, then when looking at the nth horizontal scanning line and beyond, Ym, n 9/
l YH* nquiy + Yll, (n+2)
? in.

The brightness high frequency component YII+ is obtained from the switch 13 in the order of Ym, (a+z)t in HYH, (n+4)j in + Yll, (n+a)94 in+ """.

Similarly, input terminals 2 and 3 output color difference signals C, .
C2 is input. These color difference signals C, , C2 are band-limited in the vertical direction by vertical LPFs 15 and 20, respectively.

The color difference signal CI output from the vertical LPF 15 is directly supplied to the switch 17 and is also input to the 1H delay line 16.
The signal is delayed by H and is supplied to the switch 17. Also, Taru @L
The strange color signal C2 output from the PF20 is directly supplied to the switch 22, and is also outputted from the IH delay I#A21 by 1H.
The signal is supplied to the switch 22 after a delay.

Switch 17.22, like switch 13,
The switching control is performed by the pulse from the frequency divider 14, so that the switches 17 and 22 successively output color difference signals C, , C2 of horizontal scanning lines every 1H by 2H. In other words, the color difference signal C of the %1st horizontal scanning line
Let I and C2 be C1, sy, yvct, sy, respectively,
Looking at the n-th horizontal scanning line and beyond, switch 17 outputs C+, ny ye C+, n9 in e C+, (a
dzn2iapC1, (n+2)t4y* C+, (
n+4)? The color difference signal CI is output in the order of 4yw C1, (n+a)t4y*-=, and similarly, the switch 22 outputs C2, my*C2, l19in*C
2, (+s+gt y * C2, (n+2947+C
The color difference signal C2 is output in the order of 2, (n+4) lines y + C2, and (11+4) lines + H*+H+H.

The color difference signal CI* from the switch 17 is supplied to a multiplier 18, multiplied by the carrier signal from the input terminal 5, and modulated. The modulated color difference signal C1 is limited to a desired frequency band by the BBr 19 and then supplied to the adder 25. Similarly, the color difference signal C: from switch 22 is supplied to multiplier 26.

After being multiplied by the carrier signal from the input terminal 6 and modulated, the signal is limited to a desired frequency band by the BBr 24 and supplied to the adder 25 .

In the adder 25, the two modulated color difference signals C1°C7
is added. The carrier signals supplied from the input terminals 5 and 6 have the same frequency and are shifted in phase by 90@, and as a result, the adder 25 obtains a color signal C that has been orthogonally modulated.

This color signal C is supplied to the switch 27 together with the j4 degree high frequency component Ya from the switch 13. This switch 27 is controlled by a 4H period pulse obtained by dividing the output pulse of the 172 frequency divider 14 by 172 by the 172 frequency divider 26, and divides the luminance high frequency component Yl and the color signal C by 2H.
Switch alternately each time. The operation of this switch 27 is to select the luminance high-frequency component Y of a different horizontal scanning layer for each horizontal scanning line with respect to the luminance high-frequency component Y;
Also, the color difference signals C of different horizontal scanning lines are selected one horizontal scanning line at a time. Therefore, if the color signal of the first horizontal scanning line is Ci, the switch 27 outputs YH, +
5゜.

YM, (a+gt in I C(+++2) line*
C(n+4)rai yI Yl, (n+rirai 77Y
ll, (+s+4) lie yw C(n+4)t ear-
C(-+s) line 1 The time-division multiplexed signal Y:/C of the luminance high-frequency component Y: and color signal C is obtained in the order of °°°゛0°. ◎However, the color signal C(n+2)t-in supplied to the adder 29 is the modulated color difference signal itself (a+2)? ti + C2, (n+2) fins are added, and hereafter, C(n+a9i2.・
...The same applies to K.

10,000, the luminance low-frequency component Y output from the subtractor 10 is
After being delayed by the delay wave of the vertical LPF 11 and 1H delay line 12 in the delay line 28, it is supplied to the adder 29 and added to the time division multiplexed signal Y:/C. If the luminance low-frequency component Yt, is YL, i%y, the luminance low-frequency component YL after the n-th horizontal scanning line supplied to the adder 29 is YL, n5 in" + (total 1) line - YL
, (+1+2)14yl... Therefore, from the adder 29, (YL-lay y + Yll, nyin) j (Y
z, (+++)raiy + Yff, (n*29iiy
)I(YL, (+++2)rai y+C(++g>ii y
) r (YL, (n+gt y 10(n+a)
Line 几(YL, (+1+4)rai/+Yn, (n+reraiy)+ (YL, (+s+5)raiy+Ya, (
n+a)Ijlino)U(Yr,, (Kano6)raiy 10(n+6)raiy) + (YL, (n+reline 10(a+s9in)1...) A composite signal is obtained. This composite signal is fed to the converter 30.

The K converter 60 has two frame memories, and writes and reads composite signals alternately. That is,
When the sequential scanning composite signal for one frame is written into the frame memory, the composite signal is sequentially read out every other horizontal scanning line during the 172-frame period to obtain the signal for one line scan period. During the 172 frame period, every other horizontal scanning line of the remaining frames is sequentially read out to obtain a signal for the next 1 line read period. Through this operation, a composite signal based on progressive scanning is converted into a composite signal based on interlaced scanning.

Therefore, in the first field of the composite signal by this interlaced scanning, for each IH, the 11th order, (Y mu line + Yl-
line) - (YL, (n+z)t in 10 (1%+2)
Line) I (Yc, (++
retweet l)* (Yz, (n+n) twin+L: (n
+a) Twin) tube... In the low range, the brightness low range signal YL is used, and in the high range, the brightness high range signal Yg and the color signal C are alternately multiplexed every 1H. is obtained. Also, in the second field, (Yx,, (e+Qjy+Ya, (n+2)2yy
), (Y11B n + 3) line + C (M Relay /) u (
YL, (a+i)Hn+Yll, ()44)%n)e
CYL, (n+7)? In + C (11-14) p
Ia)! . . . In the same way, the low frequency range consists of the luminance low frequency component YL, and the high frequency region consists of the luminance high frequency component Ym.
A signal is obtained in which the color signal C and the color signal C are alternately multiplexed every 1H.

The output signal of the converter 60 is added with a synchronization signal and a burst signal inputted from the input terminal 7 in an adder 31 and outputted from the output terminal 8 in order to match the signal of the current standard broadcasting system.

In the signal generated by K K in this way, there is almost no frequency overlap between the luminance signal and the chrominance signal, so they can be easily separated using a filter, and a dedicated frame memory is used to convert them into sequential scanning signals. In this receiver, a frame memory is used to convert an interlaced scanning image signal into a sequential scanning image signal, and intermittent high-frequency luminance signals and color signals at every IH are interpolated between one horizontal scanning line. to make a continuous signal. According to the obtained line-sequential scanning image signal, a reproduced image with no cross color, no dot interference, and no line flicker, and with both vertical and horizontal resolutions significantly improved compared to conventional ones, can be obtained. It is also clear that this dedicated receiver only needs to be able to perform υ sequential scanning using a frame memory, and does not require any complicated signal processing such as motion adaptive processing.

Furthermore, in the case of a receiver according to the current standard broadcasting system, in the composite signal by such interlaced scanning, the phases of the luminance high frequency component Yg, color signal C and luminance low frequency component YL are completely matched in the first field. And in the second field,
Since the phase shift is only one scan line in progressive scan (i.e., 172 scan lines in interlaced scan) and the band is limited in the vertical direction, this phase shift is almost invisible. Since the luminance high-frequency component YIIs color signal C is information for every other scanning line in the original sequential scanning, for example, scan 3 [5
Even a system with 25 lines can transmit a vertical resolution equivalent to 26Z TV lines.◇On the other hand, in the current standard broadcasting system, YC separation is performed using a comb filter between the scanning channels of interlaced scanning. [! [ is 131 TV lines.9 Therefore, in the above embodiment, the vertical resolution can be twice that of the current standard broadcasting system. this is,
This can be achieved by transmitting information for one scanning line ν in a sequential scanning state.

Further, in the above embodiment, the luminance high frequency component Yi and the color signal C change their phases every horizontal scanning line, and the color signal C and the luminance high frequency component YH are alternately multiplexed every 1H in an interlaced scanning state. Therefore, the current standard broadcast system receiver that receives this signal uses its comb filter circuit to detect the color signal C.
will be stretched to 2H period, and the amplitude will be 1/2
However, as long as a color signal of the correct hue is obtained for each scanning line, a color image of good quality can be obtained even if the image is received by a receiver using the current standard broadcasting system.

FIG. 2 is a block diagram showing another embodiment of the image signal processing device according to the present invention, in which 32 to 34 are switches, 35
-38 is a converter, 59.40 is an input signal, 41.42 is a multiplier, 45, 44 is a BPFL, 45 is an adder, and 46 is a switch, and the parts corresponding to those in FIG. 1 are given the same symbols. Duplicate explanations will be omitted.

In the embodiment shown in FIG. 1 above, the luminance signal and chrominance signal were combined and then converted into an interlaced scanning signal, but in this embodiment shown in FIG. 2, the luminance signal and chrominance signal were The signals are converted into signals using interlaced scanning and then synthesized.

In FIG. 2, the luminance high frequency component YH whose band is limited in the vertical direction by the vertical LPF 11 is thinned out every 1H by the switch 32 and then input to the converter 66. Here, I
The converter converts to interlaced scanning of sequential scanning every H, but at this time, the luminance high frequency component Ym thinned out for each IH is stored in memory! Among the written horizontal scanning lines, every other horizontal scanning line is read out in one horizontal scanning period every two horizontal scannings of interlaced scanning. As a result, the luminance high-frequency component YH for each horizontal scanning line of interlaced scanning is obtained.

That is, the switch 32 causes Ya, n, and so on.

Yg, (n+z)t in, Yil, (+m+4)
Life 1 Yil, (n+6)t in 9 ° 10 °
Assuming that the luminance high-frequency signal is extracted at 1 m of ゛°,
From converter 56, in the first field of interlaced scanning.

YH, +19i2. Mouth HYll, (n+4)? In the second field, Yil, (n+2) 21 units are output in the order of 21 units.

They are output in the order of Yu, (n+6)2i21, and so on. However, the mouth represents a horizontal scanning line that is not output.

Similarly, the color difference signals CI and C2 from the vertical LPF 15.20 are thinned out every 1H by a switch 33.34, and converted into interlaced scanning signals every 1H by a converter 37.38. Note that the output signals of the converters 37 and 38 are output during the 1H period when no signal is output from the converter 36, respectively. That is, CI, ny4y+ by switch 33
(:I, (n+2) line + CI, (n+4) line IC+, (11+6) line 1 (1° is 1 by switch 34 C2, nj in reference C2, (n+g noy y in C2, (n+4)? in, C2ban+a)24
CI, (n+2
) 5 in p mouth r CI, (n-N) F in mouth,...
..., and in the second field, CI
, aj i29 mouth, CI, (fi+4)rai y, mouth,
It is output as )*. Also, from the converter 38, in the first field of interlaced scanning, Cz, (a+z9i21) as li'i].

It is output in the order of C2, (n+69 Ishiguchi,...), and in the second field, C2, nt47w ro e C2,
(a+494ys port H++H+j) The output signals of the converters 57 and 38 are outputted to the input terminals 59 and 59, respectively.
It is modulated with carrier signals inputted from 40 that are 90 degrees out of phase with each other, and sent to the adder 45 via BPF43.44.
are added, and a color signal C that is orthogonally modulated is obtained.

The color signal C output from the adder 45 and the intermittent luminance high frequency component YH output from the converter 36 are time-division multiplexed by a switch 46 that changes every 1H, and converted into interlaced scanning by the converter 35. The adder 47 adds the luminance low-frequency component YL to the luminance low-frequency component YL. Therefore, the desired composite signal in which the color signal C and the luminance high-frequency component ya are alternately multiplexed every scanning period is obtained from the adder 29. , This composite signal is added with an interlaced scanning synchronization signal and a burst signal in an adder.

Note that in the obtained interlaced scanning image signal, in the first field, (YL-line 10Ys+, mquin), (YL, (11
+2) Line 10 (11+2) Line λ('Y,, (I
l+4) line+Ya, (a+49 inha(Yl,,(
n+6)2yy10(n+6) line)! In the order of
Also, in the second field, (YXI, (a10 twin + YII, (+s+z) lineha (Y), (n+s
) lie, +Qn+4)+in) t(YL, (+s+s
)tin+Ys+, (11+4)twin),
The order is °------.

Here, as a method for obtaining progressive scanning signals, it is also possible to simply use an imaging system that operates at the frame frequency of interlaced scanning (30 french in NTSC) and has the same horizontal scanning period length. Of course, 17 frames may be sequentially scanned at the field frequency of interlaced scanning and the signal may be used every other frame.

Furthermore, K is required to capture moving images at high resolution.

A shutter is used in the optical system, and only one light beam is used for a time that is sufficiently shorter than the time of one frame of interlaced scanning! Inject light into the conversion surface,
[Effects of the Invention] As explained above, according to the present invention, the color signal and the luminance signal are frequency-multiplexed. Color signals can be multiplexed every other horizontal eclipse line in a state where there are no gaps.

Since sequential positioning signals can be reproduced on the receiving side without complex processing such as motion adaptation, there is no image quality deterioration such as line 7 distortion, cross color, or dot interference, and the horizontal and vertical resolution is high. , it can be played back without deterioration of resolution, cross color or dot interference, and the image quality can be significantly improved.Furthermore, even when received by a receiver using the current standard broadcasting system, the saturation of one color decreases by about 6 dB. With this, it is possible to obtain a color image with the correct hue.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the image signal processing device according to the present invention, and FIG. 2 is a block diagram showing another embodiment of the image signal processing device according to the present invention. Input terminal, 2.3... Input ground of color difference signal, 8... Output terminal, 9... Bypass filter, 10... Subtractor % 12... 1H delay line, 13
...Switch, 16...1H delay line, 17...Switch, 18...Multiplier, 21...1H delay line, 2
2... Switch, 26... Multiplier, 25... Adder, 27... Switch, 29°°° Adder, 30...
・Converter, 32-34...Switch, 35-68...
・Converter, 39.40...carrier signal input terminal,
41.42... Multiplier, 45... Adder. 46...Switch.

Claims (1)

[Scope of Claims] 1. In an image signal processing device that forms an image signal by interlaced scanning from an image signal by progressive scanning, a first color difference signal by sequential scanning is extracted every other horizontal scanning line. a signal extraction means for generating a color signal by modulating and adding the first and second color difference signals from the first signal extraction means, and a signal generation means for generating a color signal by sequentially scanning a luminance signal for each color. a signal component separation means for dividing the signal into a high-frequency luminance component and a low-luminance component in the same frequency band as the signal; a second signal extraction means for extracting the high-luminance component every other horizontal scanning line; combining means for time-division multiplexing the color signal from the first signal extraction means and the luminance high frequency component from the second signal extraction means and further adding the luminance low frequency component; An image signal processing device comprising: conversion means for converting the image signal into an image signal by interlaced scanning. 2. In claim 1, the first signal extraction means includes first and second delay lines that delay the first and second color difference signals by one horizontal scanning line, respectively; 1. first and second switches that alternately select the second color difference signal and the first and second color difference signals delayed by the delay line for each horizontal scanning line; The signal extracting means includes a third delay line that delays the high-luminance component by one horizontal scanning line, and a third delay line that delays the high-luminance component and the high-luminance component delayed by the delay line by one horizontal scanning line. The combining means combines the color signal from the signal generating means and the luminance high frequency component from the third switch into one.
An image signal processing apparatus characterized in that the signal is selected alternately for each horizontal scanning line, and the converting means converts the output signal of the combining means into an image signal by interlaced scanning. 3. In claim 1, the first signal extraction means is means for extracting the first and second color difference signals every other horizontal scanning line, and the second signal extraction means is a means for extracting the first and second color difference signals every other horizontal scanning line. Means for extracting the luminance high frequency component every other horizontal scanning line, the converting means converting the output signals of the first and second signal extraction means and the luminance low frequency component into signals by interlacing scanning, respectively. An image signal processing device characterized by converting into.