JPH06292226A - Luminance signal/chrominance signal/high frequency luminance signal separator - Google Patents

Abstract

PURPOSE:To halve a required memory size for a motion adaptive separate filter by forming a C/HH signal through the sum of a C signal and an HH signal and separating a Y signal through the subtraction of the C/HH signal from the original C and HH signals. CONSTITUTION:Y/C/HH signals and a new subcarrier are multiplied at a 1st multiplier 10, and only low side band data resulting from the product passing through an LPF 11 is fed to a motion adaptive separate filter 2. The filter 2 separates the C and HH signals of the lower side band and they are multiplied respectively with the new subcarrier at 2nd and 3rd multipliers 12, 13 to restore the C and HH signals to the original band, The C and HH signals at the original band pass through respectively a BPF 115 and a BPF 216, in which the low frequency component is eliminated to obtain the C and HH signals. The obtained C and HH signals are used for C and HH signal output of the separator, both of the signals are added at an adder 18 to obtain the C and HH signals. the original Y/C/HH signals and the C/HH signals as above are fed to a subtractor 19 and the Y signal is obtained by eliminating the C/HH signals from the Y/C/HH signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Y / C / HH separation device for separating a luminance signal / color signal / high frequency luminance signal from a composite signal of a high definition television.

[0002]

2. Description of the Related Art Before explaining a conventional luminance signal / color signal / high band luminance signal (Y / C / HH) separation device of a high definition television (EDTV), first, an input composite signal will be described. Excluding sync signals).

The input composite signal is composed of a luminance signal and a color signal (C signal) containing color information. In the EDTV, the luminance signal has a frequency band of DC to 6.3 MHz, and the same low luminance signal (Y signal) of DC to 4.2 MHz as the luminance signal in the known NTSC system and 4.2 MHz to 6.
It is divided into a high-frequency luminance signal of 3MHz. The high frequency luminance signal is
The color sub-carrier (f _SC ) of about 3.58 MHz is multiplied by 16/7 and the sub-carrier of about 8.18 MHz is multiplied, and the result 1.8 is obtained.
A new high-band luminance signal (HH
Signal) is frequency-multiplexed with the Y signal.

The C signal is the same as the NTSC color signal, and f _SC is amplitude-modulated by a color difference signal of maximum 1.5 MHz, and the upper sideband is band-limited to 4.2 MHz.
It has a Hz band. As shown in FIG. 8, the C signal is changed to Y
The signal and the HH signal are frequency-multiplexed to form a new composite signal. New composite signal (Y / C / HH signal)
The three-dimensional frequency display of is shown in FIG.

A conventional Y / C / HH separator (1) is shown in FIG.
As shown in Fig. 9, first, the above Y / C / HH for two frames
The signal is stored as data in the memory (5) with the input data length and clock frequency unchanged. Furthermore, based on the stored data, C separation filter (30), HH separation filter (4
0), and a motion adaptive separation filter including a C / HH separation filter (50) and a motion detection (60), separates the C signal, the HH signal, and the multiplexed signal (C / HH signal) of the C signal and the HH signal. The subtracter 19 subtracts the separated C / HH signal from the original signal Y / C / HH signal to obtain a Y signal.

Each component of the motion adaptive separation filter (2) will be described in detail. As shown in FIG. 15, the C separation filter (30) receives an output (MD output) from a motion detection (60) described later, and receives a still image C separation filter (31) and a moving image C separation filter.
(32) is switched by the switch (MIX (23)) to adapt to movement. Still image C separation filter (31) and moving image C separation filter
Each of (32) is composed of a transversal filter, and as shown in FIG. 14, taps are made from delay units (24) having taps (a) to (k) for outputting data between frames and between lines, respectively. (a) (d) (e) (g) (i) (j) (k) inter-frame data and taps (f) (g) (h) line-to-line data are received, so-called three-dimensional and two-dimensional Operates as a comb filter, Y / C / H
Separate the C signal from the H signal. In FIG. 14, 1H is 1
It represents the delay of the horizontal scanning period. 1 field at 262.5H, 5
A delay of 1 frame occurs at 25H. Incidentally, in each of the filters shown below, the data input is obtained from a predetermined tap of the delay unit (24) as in the above. The symbols of taps (a) to (k) of the delay device (24) correspond to the symbols (a) to (k) of the input of each filter.
The memory (5) functions as the delay device (24).

The HH separation filter (40) and the C / HH separation filter (50), as shown in FIGS. 16 and 17, are still image HH separation filters (41), respectively, like the C separation filter (30).
It has a moving picture HH separation filter (42), a still picture C / HH separation filter (51) and a moving picture C / HH separation filter (52). Only the coefficient of the multiplier (21) is different, and the motion adaptive comb The operation as the separation filter operates in the same manner as the C separation filter (30) and outputs the HH signal and the C / HH signal, respectively.

The motion detection (60) is as shown in FIG.
The inter-frame data is received from the delay unit (24) of No. 4, and the difference between the current image, the image between one frame and the image two frames before is taken, and by MAX, the maximum value for the sub-sampling and the moving image or the still image An image is compared with a predetermined prescribed value for judging an image, and if the difference is equal to or larger than the prescribed value, it is determined to be a moving image, and if it is less than the prescribed value, it is determined to be a still image. (30), HH separation filter (40) and C
/ HH separation filter (50).

[0009]

The frame frequency f _f of the EDTV is 30 Hz. And the conventional digital Y
The / C / HH separation device (1) has a data length of 8 bits for two frames of the Y / C / HH signal and a clock of f _SC .
I remember it at 14.32MHz. Therefore, the total number of required memory bits = (2 frames x 8 bits x 14.32MHz) / 30H
z = 7.64 mechanical bit, which required a total memory (5) of about 8 megabits. Although the price of memory is decreasing recently,
It was still necessary to reduce the memory capacity.

[0010]

SUMMARY OF THE INVENTION The present invention discloses a device capable of reducing the memory capacity of the above problem by half. The separating device (1) has the following three devices (1): first, second and third. The first Y / C / HH separation device (1) is
As shown in FIG. 1, the Y / C / HH signal is connected to the subtracted inputs of the first multiplier (10) and the subtractor (19), and the other input of the first multiplier (10) has the color A new subcarrier fo, which is an integer proportional to the subcarrier, is added, and the output of the first multiplier (10) is connected to the motion adaptive separation filter (2) via the LPF (14) to obtain the C signal of the motion adaptive separation filter (2). The output is connected to one input of the second multiplier (11), the HH signal output is connected to one input of the third multiplier (12), and the HH signal output of the second and third multipliers (11) and (12) is connected. A new subcarrier fo is added to the other input, and the second and third multipliers (11)
The outputs of (12) are connected to BPF1 (15) and BPF2 (16), respectively, and the outputs of BPF1 (15) and BPF2 (16) output the C signal and the HH signal, respectively, and the output of the adder (18). Connected to both inputs, the output of the adder (18) is connected to the subtraction input of the subtractor (19), and the subtractor (19) outputs the Y signal.

The second Y / C / HH separator (1) is shown in FIG.
As shown in, in the first Y / C / HH separation device (1), the motion adaptive separation filter (2) includes a C signal, an HH signal,
C / HH signal is output, and the C signal, HH signal, C / HH
The signal is connected to one of the inputs of the second, third and fourth multipliers (11), (12) and (13), respectively, and the second, third and fourth multipliers (11), (12) and (1) are connected.
The new subcarrier fo is connected to the other input of 3), and the outputs of the second, third and fourth multipliers (11), (12) and (13) are respectively the first, second and
It is connected to the third BPF (15) (16) (17), and the output of the third BPF (17) is connected to the subtraction input of the subtractor (19). Therefore, the adder (18) of the first Y / C / HH separator (1) (FIG. 1) is removed.

The third Y / C / HH separator (1) is shown in FIG.
And a BPF for band-limiting the input Y / C / HH signal at point A of the first and second Y / C / HH separation devices (1) in FIG.
Insert (not shown).

[0013]

The color signal of the Y / C / HH signal and the high frequency luminance signal are
For EDTV, 2.1MHz to 4.2MHz and 1.88MHz to 3.98MHz respectively.
Has a frequency band of. Properly select the new subcarrier fo,
The first multiplier multiplies the C / HH multiplexed signal fc of the Y / C / HH signal. Now, assuming that ω = 2 x π x f _SC ω C / HH multiplex signal fc = f (t) x cos (ωt) new subcarrier fo = cos (ωt / 2 + θ), the first multiplier (10) Let f1 be the output of f1 = fc x fo = f (t) x cos (ωt) x cos (ωt / 2 + θ) = f (t) / 2 x {cos (3ωt / 2 + θ) + cos ( ωt / 2-θ)} LPF (14) is set appropriately (for example, larger than ω / 2 and smaller than ω) and the upper sideband is removed, the output f2 of LPF (14) is f2 = f (t) / It becomes 2 x cos (ωt / 2−θ), and f _SC can be suppressed to half. That is, 4xf
Memory (5) of motion adaptive separation filter (2) with _SC clock
The new motion adaptive separation filter
For (2), 2xf _SC is sufficient, and the memory (4) size can be halved.

The size of the memory (4) of the new motion adaptive separation filter (2) is reduced to half the size of the memory (5) of the conventional motion adaptive separation filter (2), and the operation clock is also halved. , The basic function and operation are the same as the conventional motion adaptive separation filter (2). The output of the new motion adaptive separation filter (2) is the C signal, the HH signal, and the second Y signal.
/ C / HH separation device (1) motion adaptive separation filter
For the C / HH signal of (2), the subsequent demodulation processing will be the same for each signal, so an arbitrary one signal will be described.

In order to confirm that the signal is demodulated further, an arbitrary one signal f2 of the output of the new motion adaptive separation filter is set to the same f2 = f (t) / 2 x cos (ωt / 2-θ) as above. Considering the case where f2 is input to the second multiplier (11) as a representative, the output f3 of the second multiplier (11) is f3 = f (t) / 2 x cos (ωt / 2 -θ) x cos ( ωt / 2 + θ) = f (t) / 4x {cos (ωt) + cos (-2xθ)}. Set the band of BPF1 (15) appropriately, and
The following equation is obtained by setting the output of 1 (15) to f4 (however, BPF1
Has a gain of 4). f4 = f (t) x cos (ωt) That is, the original signal can be demodulated.

As described above, in the motion adaptive separation filter (2) of the first Y / C / HH separation device (1), the C signal, HH
Demodulate the signal. At the same time as outputting the C signal and the HH signal, both signals are added by an adder (18) to create a C / HH signal, and the addition is performed from the original Y / C / HH signal by a subtractor (19). The C / HH signal obtained by the above is subtracted to separate the Y signal.

The second Y / C / HH separation device (1) separates the C signal and the HH signal by the motion adaptive separation filter (2), and simultaneously separates the composite signal of the C / HH signal. Therefore, the first adder (18) in the first Y / C / HH separation device (1) becomes unnecessary, and the C / HH signal obtained from the motion adaptive separation filter (2) becomes a subtracter (18). 19) to separate the Y signal.

The third Y / C / HH separator (1) has a first
Also, a BPF (not shown) is inserted in the input stage of the second Y / C / HH separation device (1) (1) to remove unnecessary components of the luminance signal in advance, and the first multiplier ( 10) plus the first multiplier (1
C) at the output of 0), the influence of the luminance signal on the HH signal, and the affected C signal at the output of the subtracter (19),
The influence of the HH signal on the luminance signal is completely eliminated.

[0019]

According to the present invention, a motion adaptive separation filter is provided.
The required memory size of (2) can be halved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In this embodiment, the frequency fo of the new subcarrier is
Is set to 1.79 MHz, which is 1/2 of f _SC , and the same Y / C / HH signal as that of the related art shown in FIGS. 8 and 9 is input. (First embodiment) Y / C / HH separator of the first embodiment (1)
Is the frequency of the new subcarrier, fo, as described above, f _SC /2=1.7
The LPF (14) was set to 9 MHz, and the LPF (14) was composed of the 8-stage transversal filter shown in FIG. 6, and the band was set to 2.5 MHz with a rectangular window. BPFs 1 and 2 (15) and (16) are the same transversal type bandpass filters as shown in FIG. In the figure, "1D" is a 1-data delay unit (27).

The input Y / C / HH signals are shown in FIGS.
One-dimensional and three-dimensional frequency display respectively. The Y / C / H
When the H signal and the new subcarrier are multiplied in the first multiplier (10), the outputs are one-dimensional and three-dimensional frequency-represented outputs in FIGS. 10 and 11, respectively. As can be seen from both figures, the lower sidebands of the C and HH signals are 0.31MHz to 2.4, respectively.
1 MHz, distributed 0.09MHz～2.19MHz, upper sideband C ₁ signal and HH ₁ signals respectively 3.89MHz~5.99MHz and 3.67MHz~5.77
Distributed in MHz. The both sidebands have a band of 2.5 MHz LPF (1
4) to remove the upper sideband, separate only the lower sideband as shown in FIGS. 12 and 13, and send the separated one to the motion adaptive separation filter (2) as data.

As shown in FIG. 3, the motion adaptive separation filter (2) comprises a memory (4) of 4 megabits / 2 frames, a C separation filter (30), an HH separation filter (40) and a motion detection (2). The configuration and operation of 60) are the same as the conventional one.

The C and HH signals of the lower sideband are separated by the motion adaptive separation filter (2), and the C and HH signals are separated.
The signal is multiplied by the new subcarrier in the second multiplier (11) and the third multiplier (12), respectively, and as described in the section of operation,
The C signal and the HH signal are returned to the original band. C of the original band
Signal and HH signal to BPF1 (15) and BPF2 (16) respectively
To remove the low frequency component and obtain the C signal and the HH signal. The obtained C signal and HH signal are output as the C signal and HH signal of the present apparatus, while the adder (18) adds both signals to obtain a C / HH signal. The original Y / C / HH signal and the C / HH signal are added to the subtractor (19), and Y / C / HH
The Y signal is obtained by removing the C / HH signal from the signal.

(Second Embodiment) Y / C / HH of the second embodiment
LPF (14) and BPF 1-2 (15) (16) of the separation device (1)
And the operation up to the motion adaptive separation filter (2)
This is the same as the device (1) of the first embodiment. In addition, BPF3
(17) also has the same structure as BPF1 (15) and BPF2 (16).

The second Y / C / HH separator (1) is shown in FIG.
And as shown in FIG. 4, the first Y / C / HH separation device described above.
A C / HH separation filter (50) is added to (1). As shown in FIG. 5, the C / HH separation filter (50) receives data between frames and lines from the delay unit (24) (FIG. 14) as in the conventional case, and in the case of a still image, a still image C / H H
The H separation filter (51) operates as a three-dimensional separation filter, and in the case of a moving image, the moving image C / HH separation filter (52) operates as a two-dimensional separation filter.

The motion adaptive separation filter (2) has a C signal, H
In addition to the H signal, the C / HH signal is further separated and output. A fourth multiplier (13) and a BPF3 (17) restore the output to the original band and further remove low frequency components to demodulate into a C / HH signal,
The C / HH signal is added to the subtraction input of the subtractor (19), and the original Y
The C / HH signal is subtracted from the / C / HH signal to obtain the Y signal. Others are the same as the first embodiment.

(Third Embodiment) The third Y / C / HH separator (1) is the same as the first and second Y / C / HH separators (1).
In the Y / C / HH signal of the input of the first multiplier (10),
A BPF (not shown) for band limitation is added to remove the influence of the high frequency component of the Y signal on the C signal and the HH signal.

The first to fourth multipliers (10) (11) (12) (13), the adder (18) and the subtractor (19) used in this embodiment are:
It is known.

The above description of the embodiments is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. The configuration of each part of the present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

FIG. 1 is a block diagram of a first embodiment of the present invention.

FIG. 2 is a block diagram of a second embodiment of the present invention.

FIG. 3 is a block diagram of a Y / C / HH separator according to the first embodiment.

FIG. 4 is a block diagram of a Y / C / HH separation device according to a second embodiment.

FIG. 5 is a block diagram of a C / HH separation filter of the present invention.

FIG. 6 is a block diagram of an LPF.

FIG. 7 is a block diagram of a BPF.

FIG. 8 is a frequency spectrum of a Y / C / HH signal.

FIG. 9 is a three-dimensional frequency spectrum of a Y / C / HH signal.

FIG. 10 is a frequency spectrum of the C / HH signal at the output of the first multiplier.

FIG. 11: C / HH signal 3 at the output of the first multiplier
Dimensional frequency spectrum.

FIG. 12 is a frequency spectrum of the C / HH signal at the LPF output.

FIG. 13 is a three-dimensional frequency spectrum of the C / HH signal at the LPF output.

FIG. 14 is a block diagram of a delay device.

FIG. 15 is a block diagram of a C separation filter.

FIG. 16 is a block diagram of an HH separation filter.

FIG. 17 is a block diagram of a conventional C / HH separation filter.

FIG. 18 is a block diagram of motion detection.

FIG. 19 is a block diagram of a conventional Y / C / HH separation device.

[Explanation of symbols]

 (1) Y / C / HH separation device (2) Motion adaptive separation filter (4) Memory (10) First multiplier (11) Second multiplier (12) Third multiplier (13) Fourth multiplier ( 14) LPF (15) BPF1 (16) BPF2 (17) BPF3 (18) Adder (19) Subtractor

Claims (3)

[Claims] 1. A new composite signal is stored in a memory as data, a high-frequency luminance signal and a color signal are separated by a motion adaptive separation filter based on the stored data, and further separated from the new composite signal. In a luminance signal / color signal / high-frequency luminance signal separation device that separates a low-frequency luminance signal by subtracting a high-frequency luminance signal and a color signal, a new composite signal is subtracted from a first multiplier and a subtractor. The input of the first multiplier is connected to the other input of the first multiplier by a new subcarrier which is an integer proportional to the color subcarrier, and the output of the first multiplier is connected to the motion adaptive separation filter via the LPF. C signal output is connected to one input of the second multiplier, HH signal output is connected to one input of the third multiplier, and the other inputs of the second and third multipliers are respectively connected to the new sub unit. Add carrier and add second and third power The output of the vessel are each BPF1
And BPF2, the outputs of BPF1 and BPF2 output the C signal and the HH signal, respectively, and are connected to both inputs of the adder, the output of the adder is connected to the subtraction input of the subtractor, and the subtractor is A luminance signal / color signal / high-frequency luminance signal separation device characterized by outputting a Y signal. 2. The motion adaptive separation filter is a C signal, HH.
Signal, C / HH signal, and outputs the C signal, HH signal, C
/ HH signal is connected to one input of the second, third, and fourth multipliers, respectively, and a new subcarrier is connected to the other input of the second, third, and fourth multipliers. The luminance signal according to claim 1, wherein the outputs of the third and fourth multipliers are respectively connected to the first, second and third BPFs, the output of the third BPF is connected to the subtraction input of the subtractor, and the adder is removed. Color signal / high frequency luminance signal separation device. 3. The luminance signal / chrominance signal / high frequency luminance according to claim 1 or 2, wherein an input new composite signal is applied to an input of a band-limited BPF, and an output of the BPF is applied to a first multiplier. Signal separation device.