JPH11150709A - 420p signal processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the deterioration of the vertical resolution of a color difference signal by replacing a main signal and a sub signal only by a luminance signal when frames are not coincident with each other. SOLUTION: A judging means 4 judges that the frame of the output of a judging means 2 for the frame of picture data is coincident with the frame of the output of a detecting means 3 for a transmission frame. Then, the result and reproduced picture data are inputted to a conversion means 5 to replace the main signal side and the sub signal side of a luminance signal only by a frame whose the frame is judged to be noncoincident. A separation means 7 separates the 420P signal of the output of the means 5 into the luminance signal on the signal side on the main side, the luminance signal on the side of the sub signal and a color difference signal and a first signal preparing means 8 multiplexes the luminance signal on the side of the main signal and the color difference signal to output from an output terminal 10 as a 422P main signal. A second signal preparing means 9 multiplexes the luminance signal on the side of the sub signal and the color difference signal to output from an output terminal 11 as a 422P sub signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 420P signal processing apparatus for transmitting a 420P signal and performing signal processing such as 420P / 422P conversion.

[0002]

2. Description of the Related Art First, a 420P signal will be briefly described. The 420P signal is different from the current interlaced signal and is based on a progressive signal (sequential scanning signal).

FIG. 8 is a schematic diagram showing an interlaced system and a progressive system. As shown in the figure, in the interlaced mode, about 30 image data (frames) per second
And has 525 scanning lines per sheet. In one image data having 525 scanning lines, the interlacing method is such that scanning lines are skipped one by one and transmitted 262.5 lines in 1/60 second. The progressive system, unlike the interlace system, transmits 525 image data per 1/60 second without interlaced scanning.

[0004] The progressive signal sequentially scanned at 525 lines per screen is a Recommendation ITU-R.6.
It is digitized in the format of 8: 4: 4, which is twice the sampling frequency of 4: 2: 2 specified in 01-3, the sampling frequency of the luminance signal is 27 MHz, and the sampling frequency of the color difference signal is 13.5 MHz. , Quantized with 10 bits.

The above-mentioned 8: 4: 4 signal is alternately divided for each line, and a main signal composed of one luminance signal and two color difference signals, and a main signal that interpolates the main signal.
There is a method in which a signal is divided into sub-signals composed of one luminance signal and two color difference signals and transmitted. The main signal and the sub signal of this system are 525 interlace signals having 525 scanning lines per frame, and are 4: 2: 2 signals. By combining the main signal and the sub signal,
It is called a 4: 2: 2: 4: 2: 2 signal (422P signal).

Before dividing the 8: 4: 4 signal into a main signal and sub-signals, the vertical frequency band of the color difference signal is restricted by a line thinning vertical filter.
The signal is called an 8: 4: 4v signal. As a line thinning vertical filter, a three-tap 1: 2: 1 filter is being studied.

FIG. 9 shows a configuration of a line thinning vertical filter. In the figure, [2] and [1/4] indicate coefficients of the multiplier. The 8: 4: 4v signal obtained by thinning out the color difference signal by the line thinning vertical filter is transmitted as a 4: 2: 2: 4 signal not including the color difference signal in the sub signal. The 4: 2: 2: 4 signal is also called a 420P signal, and is hereinafter referred to as a 420P signal.

[0008] A standardized version of the 420P signal as a 360 MHz serial interface is SMPTE.
FIG. 10 shows a schematic diagram of a 294M signal encoded with a 420P signal. As shown in the figure, the effective portion of one horizontal line of the interlaced signal is expanded, and the main signal Ym and the sub-signal Ys of the luminance signal and the main signals Pb and P of the color difference signal are expanded.
r is mapped to one horizontal line and transmitted. This means that 2160 samples out of 2288 samples in one horizontal line are used as the effective part.

FIG. 11 shows the correspondence between the 420P signal and the scanning lines on the TV screen. The luminance signal is always composed of 525 lines / 1 frame for both odd and even frames, whereas the color difference signal is always present only on the main signal side as shown in FIG. The screen position of the line is shifted by one line, and is constituted by 525/2 lines per frame (the same as the pixel position of the interlace signal).

[0010] 42 corresponding to the above SMPTE294M
An image data processing device for transmitting and monitoring a 0P signal has not been commercialized at present. However, SMPTE 294
M specifies how to receive a 420P signal and create a 422P signal.

According to SMPTE 294M, the received 4
The color difference signal of the 20P signal is extracted, and the color difference signal on the sub signal side is interpolated from the color difference signal on the main signal side by a color difference signal interpolation circuit using a vertical filter.

FIG. 12 shows a configuration diagram of the interpolation circuit. [-38], [294], and [1/512] in FIG. In the interpolation circuit, a color difference signal on the sub signal side is created by inputting a color difference signal on the main signal side and passing through a vertical filter. Thus, the 4: 2: 2: 4: 2: 2 signal (4
22P signal). By creating a 422P signal,
By changing the clock frequency to a double rate, the clock frequency can be converted to 844 signals and monitored on a TV screen.

According to Japanese Patent Application Laid-Open No. Hei 8-205088, when the frame of the output synchronization signal does not match the frame of the image data, as in the case of slow reproduction of a VTR or the like, the luminance signal becomes the main signal. And sub-signals are interchanged and output, and the color difference signal is the interpolated color difference signal on the main side,
The original color difference signal is output on the sub side to improve the image quality of image data during slow reproduction.

[0014]

However, the output signal of the conventional signal processing device is a signal composed of two systems of a main signal and a sub signal, and there is no description about the case of outputting as a 420P signal.

Now, the 4 signal output from the conventional signal processing device is
Consider a problem when a 22P signal is transmitted as a 420P signal and then converted to a 422P format again on the receiving side.

FIG. 13 shows a 422P signal composed of two main and sub systems output from a conventional signal processing device.
A configuration diagram in the case of converting to a 0P signal, transmitting the signal, and converting the signal to a 422P signal or 844 signal again on the receiving side and monitoring it on a TV screen is shown. In the figure, 51 is a conventional signal processor, 52 is a 422P-420P converter, 53 is a transmission cable, 54 is a 420P-422P converter, and 55 is T
It is a V monitor. FIGS. 14 and 15 show timing charts of respective parts in the system of FIG. FIG.
FIG. 15 is a timing chart in the case where the image data frame and the output frame match in the conventional signal processing device 51, and FIG.
FIG. 6 is a timing chart when a frame of image data does not match an output frame.

FIG. 14A is a timing diagram of the output of the main signal of the conventional signal processing device, and FIG. 14B is a timing diagram of the output of the sub-signal of the conventional signal processing device. In the figure, Ym indicates a luminance signal component of a main signal when input to a conventional signal processing device or a luminance signal component of a recorded main signal. Ys indicates a luminance signal component of a sub-signal when input to a conventional signal processing device or a luminance signal component of a recorded sub-signal. Cm indicates the color difference signal component of the main signal when input to the conventional signal processing device, the color difference signal component after passing through the filter in FIG. 9, or the recorded color difference signal component. Cho indicates a color difference signal component generated by converting Cm by the interpolation circuit shown in FIG. FIG. 14C shows 422P-420.
The timing chart of the output signal of the P converter 52, FIG.
A timing diagram of the output signal of the OP-422 converter 54 is shown.

FIGS. 15A, 15B, 15C, and 15D show FIGS.
4, the timing chart of each part and each reference numeral are the same as those in FIG. Also, Cho is a color difference signal component created from Cho by the interpolation circuit of FIG.

Considering FIGS. 14 and 15, FIG.
As shown in FIG. 15, when the frame of the image data and the output frame coincide with each other, the Cm signal is transmitted until (d). However, as shown in FIG. If not, Cm is (d)
Not transmitted until. Therefore, the color difference signals of the image monitored on the TV screen are all only components due to the interpolation filter, and as a result, there is a problem that the band in the vertical direction of the color difference signals is deteriorated.

Considering the case where the system shown in FIG. 13 is cascaded, the amount of degradation of the vertical band of the color difference signal when the number of stages of connection increases and the frame of the image data and the output frame do not match. When viewed on a screen, the number of screen flickers is increased in frames that match and frames that do not match.

The present invention is to improve the screen flicker of the color difference signal in the transmission of the 420P signal and to improve the vertical resolution of the color difference signal when the 420P signal is slow-reproduced by a VTR or the like and recorded again. .

[0022]

According to the present invention, there is provided an image frame detecting means for detecting whether an image data frame to be transmitted is an odd frame or an even frame, and a synchronizing signal to be transmitted. Transmission frame detecting means for detecting whether the frame is an odd frame or an even frame, and determining whether or not the frame of the image data output from the image frame detecting means matches the frame of the transmission frame detecting means. If the determination means and the determination means match the frame, the image data
A conversion means is provided for outputting as a 20P signal, and when they do not coincide with each other, only the luminance signal is replaced with the main signal and the sub signal, and the color difference signal is output as it is as a 420P signal.

If they do not match, only the luminance signal is replaced with the main signal and the sub signal, and the color difference signal is output as it is as a 420P signal. Flag inserting means for inserting the signal into the signal.

This makes it possible to prevent the band of the color difference signal from deteriorating.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, in an apparatus for transmitting a 420P signal, an image frame detecting apparatus detects whether an image data frame to be transmitted is an odd frame or an even frame. Means, a transmission frame detection means for detecting whether the frame of the synchronization signal to be transmitted is an odd frame or an even frame, and a frame of the image data output from the image frame detection means and a frame of the transmission frame detection means. Determining means for determining whether or not they match each other; if the frames match, the image data is output as it is as a 420P signal; if not, only the luminance signal includes the main signal and the sub signal. And replace the color difference signal with 4
A conversion means for outputting a 20P signal, and has an effect of transmitting a base color difference signal as a 420P signal even when a frame of image data and a transmission frame do not match.

Further, the invention according to claim 2 of the present invention provides:
4. The signal transmitted by the processor for processing a 420P signal according to claim 1.
In a device that receives a 20P signal and converts it into a 422P signal or a 844 signal, the color difference signal component of the 420P signal is separated and copied as it is as a color difference signal on the sub signal side.

[0027] The invention described in claim 3 of the present invention provides:
In a device for transmitting a 420P signal, an image frame detecting means for detecting whether an image data frame to be transmitted is an odd frame or an even frame, and a frame of a synchronization signal to be transmitted is an odd frame or an even frame. Transmission frame detection means for detecting whether or not the frame of the image data output from the image frame detection means and the frame of the transmission frame detection means coincide with each other; If they do not match, a flag inserting means for inserting a flag into the 420P signal is provided, and a flag is inserted into a frame where the image frame and the transmission frame do not match.

Further, according to a fourth aspect of the present invention, a 420P signal transmitted by the 420P signal processing apparatus according to the third aspect is received, and a 422P signal or 84
4. An apparatus for converting into four signals, a flag detecting means for detecting a flag according to claim 3, and a color difference signal for generating a second color difference signal by separating and interpolating a first color difference signal transmitted as a 420P signal. A color difference signal of a frame in which a flag has not been detected by the interpolation means and the flag detection means includes a first color difference signal as a color difference signal on a main signal side, a second color difference signal as a color difference signal on a sub signal side, and a luminance signal. The main signal corresponds to the main signal, the sub signal corresponds to the sub signal, and the color difference signal of the frame in which the flag is detected is the first color difference signal for the sub signal side color difference signal, and the second color difference signal for the main signal side. The color difference signal, the luminance signal, the main signal is made to correspond to the sub signal, the sub signal is characterized by comprising conversion means to correspond to the main signal, the flag detection means to detect a flag, Difference signal, and controlled by the flag in both the luminance signal, it is performed switching of the main signal and the sub signal.

Further, the invention according to claim 5 of the present invention provides:
In a device for transmitting a 420P signal, an image frame detecting means for detecting whether an image data frame to be transmitted is an odd frame or an even frame, and a frame of a synchronization signal to be transmitted is an odd frame or an even frame. Transmission frame detection means for detecting whether or not the frame of the image data output from the image frame detection means and the frame of the transmission frame detection means coincide with each other; If they match, the image data is output as it is as a 420P signal. If they do not match, only the luminance signal is replaced with the main signal and the sub signal, and the color difference signal is
It has a converting means for outputting as a P signal and a flag inserting means for inserting a flag into the 420P signal when the frame is not coincident with the judging means, so that only the luminance signal is replaced with the main signal and the sub signal. A flag is inserted in the frame.

Further, according to a sixth aspect of the present invention, a 420P signal transmitted by the 420P signal processing device according to the fifth aspect is received, and a 422P signal or 84
4. An apparatus for converting into four signals, a flag detecting means for detecting a flag according to claim 3, and a color difference signal for generating a second color difference signal by separating and interpolating a first color difference signal transmitted as a 420P signal. The frame in which the flag is not detected by the interpolation means and the flag detection means is a frame in which the first color difference signal is a color difference signal on the main signal side and the second color difference signal is a color difference signal on the sub-signal side, and the flag is detected. And a conversion means for converting the first color difference signal into a color difference signal on the sub-signal side and converting the second color difference signal into a color difference signal on the main signal side. ,
The color difference signal transmitted with the color difference signal and the color difference signal interpolated by the color difference signal interpolation means are replaced by the conversion means.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG.
FIG. 2 is a block diagram illustrating a configuration of a signal processing device. In the present embodiment, a 420P signal is reproduced by a
The 0P signal is transmitted coaxially, and the 420P signal is
It is converted to a 2P signal and monitored on a TV screen.

In FIG. 1, reference numeral 1 denotes a VTR reproduction data input terminal, 2 denotes image data frame detection means for detecting whether an image data frame is an even frame or an odd frame, and 3 denotes a frame to be transmitted. Is a transmission frame detecting means for detecting whether the frame is an even frame or an odd frame, 4 is a judging means for judging whether the frame of the image data frame detecting means 2 and the frame of the transmitting frame detecting means are coincident, and 5 is A conversion means for outputting the 420P signal without processing if the frames match in the determination means 4 and replacing the main signal and the sub-signal only for the luminance signal when the frames do not match;
Is a transmission cable, 7 is separating means for separating the transmitted 420P signal into a luminance signal and a chrominance signal, and 8 is 422 by adding the chrominance signal separated by the separating means 7 to the transmitted luminance signal component on the main signal side. A first signal generating means 9 for generating a signal is a second signal generating means 9 for generating a 422 signal by adding a color difference signal output from the separating means to the transmitted luminance signal component on the sub-signal side, and 10 is a 422P signal. An output terminal for the main signal, and 11 is an output terminal for the 422P sub-signal.

The operation of the apparatus for processing a 420P signal configured as described above will be described in detail. The reproduction data input from the input terminal 1 is input to the image data frame detection means 2 to detect a frame of the image data.
The reproduction data input from the input terminal 1 can easily detect the frame of the recorded image data by detecting the ID or the like of each track of the VTR. The transmission frame detecting means 3 detects whether the frame to be transmitted is an even frame or an odd frame based on a reference signal (not shown). Also, the judgment means 4
Then, it is determined whether the output frame of the image data frame determination means 2 and the output frame of the transmission frame detection means 3 match, and output. Judgment means 4
And the reproduced image data input to the input terminal 1 are
Only the frame that is input to the conversion unit 5 and whose frame is determined to be mismatched by the determination unit 4 is switched between the main signal side and the sub signal side of the luminance signal. 4 of the output of the conversion means 5
The 20P signal is transmitted by the coaxial cable 6 and input to the separating means 7. The separating means 7 separates the 420P signal into a luminance signal on the main signal side, a luminance signal on the sub-signal side, and a chrominance signal. Plex 42
It is output from the output terminal 10 as a 2P main signal. The second signal generating means 9 multiplexes the luminance signal on the sub-signal side and the chrominance signal, and outputs the multiplexed signal from the output terminal 11 as a 422P sub-signal.

FIG. 2 is a timing chart in the case where the frame of the image data and the output frame match by the judging means 4, and FIG. 3 shows the case where the frame of the image data does not match the output frame in the judging means 4. FIG.
2 and 3, (a) shows the output 42 of the conversion means 5.
(B) is a 422P main signal output from the output terminal 10, (c) is a 422P sub signal output from the output terminal 11, Ym is a luminance signal on the main signal side recorded on the tape, and Ys is The luminance signal on the sub-signal side recorded on the tape, and Cm indicates the color difference signal recorded on the tape. As apparent from FIGS. 2 and 3, the obtained 422P
The main signal and the sub-signal are the same, and only the Ym and Ys are interchanged in the luminance signal, and the vertical band does not change for each frame so that the screen flicker does not occur. Also, the color difference signal of the 420P signal output from the conversion means 5 always outputs the recorded signal.
Even if the 420P signal is recorded and reproduced again, the vertical resolution is constant.

On the receiving side, the color difference signal transmitted as the 420P signal is compared with the 422P signal main signal and 422P signal.
The reason why interpolation is not performed by the vertical filter by allocating to both sub-signals of the P signal will be described.

FIG. 4 is a schematic diagram showing the vertical pixel position of the color difference signal of the 420P signal. In the figure, column (a) is the pixel position of the luminance signal, column (b), column (c), column (d),
The (e) column shows the pixel position of the color difference signal, respectively, and (b)
(C) shows the case where the color difference signal of the odd frame exists in the even frame, and (d) shows the case where the color difference signal of the odd frame exists in the even frame. If it exists,
(E) is a case where the color difference signal of the even frame exists in the odd frame. As shown in the figure, two samples of the color difference signal correspond to one sample of the luminance signal. Therefore, the effect of creating a sample at the midpoint between the two samples using the interpolation filter is small. Therefore, in the present embodiment, similar performance is realized with less expensive hardware without using an interpolation filter.

As described above, in this embodiment, the color difference signal always transmits the recorded color difference signal as the color difference signal component of the 420P signal. Image flicker does not occur. Also, the 420P signal output from the conversion means 5 of the present system is
The vertical resolution of the color difference signal does not degrade even when recorded and reproduced on a TR or the like. Furthermore, since an interpolation filter is not used, it can be realized with inexpensive hardware.

However, in the first embodiment of the present invention, since the same color difference signal is output to the main signal side and the sub signal side of the 422P signal, there is a disadvantage that the gradation in the vertical direction of the color difference signal is deteriorated. . Embodiment 2 of the present invention solves the above-mentioned disadvantage.

(Embodiment 2) FIG. 5 is a block diagram showing a configuration of a 420P signal processing apparatus according to Embodiment 2 of the present invention.

In FIG. 1, reference numeral 1 denotes a VTR reproduction data input terminal, 2 denotes image data frame detecting means for detecting whether an image data frame is an even frame or an odd frame, and 3 denotes a frame to be transmitted. Is a transmission frame detecting means for detecting whether the frame is an even frame or an odd frame, and 4 is a judging means for judging whether or not the frames of the image data frame detecting means 2 and the transmitting frame detecting means 3 match. Is output as a 420P signal without processing when the frames match in the determination means 4, and when the frames do not match, the conversion means outputs the luminance signal by exchanging the main signal and the sub signal.
1 is a flag inserting means for inserting a flag into a frame determined to be mismatched by the determining means 4, 6 is a transmission cable, 7 is a separating means for separating a transmitted 420P signal into a luminance signal and a color difference signal, and 22 is a frame-by-frame Flag detecting means for detecting whether or not a flag has been inserted;
Color difference signal interpolating means for generating a second color difference signal by a vertical interpolation filter from the first color difference signal separated by
A switching unit 24 switches the first color difference signal and the second color difference signal according to the flag detected by the flag detection unit 22 and outputs the first and second color difference signals. Reference numeral 8 denotes first signal generation means for generating a 422 signal by adding the color difference signal switched by the switching means 24 to the transmitted luminance signal component on the main signal side. Reference numeral 9 denotes a luminance signal component on the transmitted sub signal side. A second signal generating means for generating a 422 signal by adding the color difference signal output from the switching means 24 is an output terminal of a 422P main signal, and 11 is an output terminal of a 422P sub signal.

The operation of the apparatus for processing a 420P signal configured as described above will be described in detail. The reproduction data input from the input terminal 1 is input to the image data frame detection means 2 to detect a frame of the image data.
The reproduction data input from the input terminal 1 can easily detect the frame of the recorded image data by detecting the ID or the like of each track of the VTR. The transmission frame detecting means 3 detects whether the frame to be transmitted is an even frame or an odd frame based on the reproduction reference signal. The determination means 4 determines whether the output frame of the image data frame from the determination means 2 matches the output frame of the transmission frame detection means 3 and outputs it. The result of the judging means 4 and the reproduced image data inputted to the input terminal 1 are inputted to the converting means 5, and only the frames for which the judging means 4 judges that the frames do not match are provided on the main signal side and the sub signal side of the luminance signal. Will be replaced. The image data output from the conversion unit 5 is input to the flag insertion unit 21, and the flag is inserted and output only for the frame determined to be non-matching by the determination unit 4. The 420P signal output from the flag insertion means 21 is transmitted by the coaxial cable 6, and the flag detection means 22
And the flag for each frame is detected. Also,
The 420P signal transmitted by the coaxial cable 6 is input to the separating means 7. The separating means 7 separates the 420P signal into a luminance signal on the main signal side, a luminance signal on the sub signal side, and a first color difference signal. Further, the first color difference signal separated by the separation means 7 is input to the color difference signal interpolation means 23, and the second color difference signal is created by the vertical interpolation filter shown in FIG. The first color difference signal and the second color difference signal are input to the switching unit 24. The switching means 24 performs switching as described below according to the flag of the output of the flag detection means 22.

Frame where no flag is detected First color difference signal is input to first signal generation means 8 Second color difference signal is input to second signal generation means 9 Frame where flag is detected First color difference The signal is input to the second signal generating means 8 The second chrominance signal is input to the first signal generating means 9 Further, the first signal generating means 8 outputs the luminance signal on the main signal side of the output of the separating means 7 and A 422 signal is created from the color difference signal output from the switching means 24 and output from the output terminal 10 as a 422P main signal. Further, the second signal generating means 9 generates a 422 signal from the luminance signal on the sub-signal side of the output of the separating means 7 and the color difference signal of the output of the switching means 24, and outputs it from the output terminal 11 as a 422P sub-signal.

Further, the timing of each section will be described in detail with reference to FIGS. FIG. 6 is a timing chart in the case where the frame of the image data and the output frame coincide with each other by the judging means 4 of FIG. 5, and FIG. 7 shows that the frame of the image data coincides with the frame of the output by the judging means 4 of FIG. FIG. 4 shows a timing chart in a case in which no operation is performed. 6 and 7, (a) shows the 420P signal of the output of the conversion means 5 of FIG. 5, (b) shows the 422P main signal of the output of the output terminal 10 of FIG. 5, and (c) shows the output terminal 11 of FIG. 422P sub-signal of the output of
m is the luminance signal on the main signal side recorded on the tape,
Ys is a luminance signal on the sub signal side recorded on the tape,
Cm indicates the color difference signal recorded on the tape, and Cho indicates the color difference signal interpolated by the color difference signal interpolating means 23. As is clear from FIGS. 6 and 7, one of the obtained color difference signals of the 422P main signal and the sub-signal is always the original signal and the other is the interpolation signal. In the luminance signal, Ym and Ys
Are merely replaced, so that the vertical band does not change for each frame, so that screen flicker does not occur. Also, the color difference signal of the 420P signal output from the conversion means always outputs the recorded signal.
Even if the 0P signal is recorded and reproduced, the vertical resolution is constant. Further, since the interpolation filter for the color difference signal uses the high-order filter shown in FIG. 12, the gradation of the color difference signal is good.

As described above, in this embodiment, the color difference signal always transmits the recorded color difference signal as the color difference signal component of the 420P signal, and the phase of the color difference signal to be transmitted in the vertical direction is shifted to the sub signal side. When the signal matches the luminance signal, the flag is inserted and transmitted.Therefore, the receiving side detects the flag, and transmits the transmitted color difference signal and the color difference signal interpolated by the color difference signal interpolation means to the main signal side and the sub signal. Can be remapped to the side. Therefore, the vertical resolution of each frame is constant and does not cause flicker. Also, a good gradation of the color difference signal in the vertical direction can be obtained.

In the present embodiment, the main signal and the sub-signal of the luminance signal are exchanged on the transmitting side so that 420 P
Although transmitted as a signal, it goes without saying that the main signal and the sub-signal may be exchanged by detecting the flag on the receiving side without transmitting the main signal and the sub-signal on the transmitting side.

[0046]

As described above, according to the first and second aspects of the present invention, the judging means judges whether or not the frame of the image data matches the frame of the transmission, and performs the conversion. By replacing the main signal and the sub signal only by the luminance signal, the color difference signal always transmits the recorded color difference signal as the color difference signal component of the 420P signal, so that an image with the same vertical resolution can be obtained. As a result, screen flicker does not occur.
Even if the 420P signal output from the conversion means of the present system is recorded and reproduced on a VTR or the like again, the vertical resolution of the color difference signal does not deteriorate. Further, since a color difference signal interpolation filter is not used, it can be realized with inexpensive hardware.

According to the third to sixth aspects of the present invention, the color difference signal is always the recorded color difference signal.
When the color difference signal component of the 0P signal is transmitted and the phase of the color difference signal to be transmitted in the vertical direction matches the luminance signal of the sub signal side, a flag is inserted and transmitted. Thus, the transmitted color difference signal and the color difference signal interpolated by the color difference signal interpolation means can be remapped to the main signal side and the sub signal side. Therefore, the vertical resolution of each frame is constant and does not cause flicker. Also, a good gradation of the color difference signal in the vertical direction can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a 420P signal processing device according to a first embodiment of the present invention.

FIG. 2 is a timing chart of each unit when a frame is matched by a determination unit of the processing apparatus.

FIG. 3 is a timing chart of each unit when a frame does not match by a determination unit of the processing apparatus.

FIG. 4 is a timing chart of a vertical luminance signal and a color difference signal of a 420P signal.

FIG. 5 is a block diagram showing a configuration of a 420P signal processing device according to a second embodiment of the present invention.

FIG. 6 is a timing chart of each unit when a frame coincides with a determination unit of the processing apparatus.

FIG. 7 is a timing chart of each unit when a frame is not matched by a determination unit of the processing apparatus.

FIG. 8 is a schematic diagram showing a difference between an interlace system and a progressive system.

FIG. 9 is a configuration diagram of a line thinning filter.

FIG. 10 is a schematic diagram when a 420P signal is encoded.

FIG. 11 is a schematic diagram showing correspondence between 420P signals and scanning lines on a TV screen.

FIG. 12 is a configuration diagram of a vertical interpolation filter.

FIG. 13 is a configuration diagram of a conventional 420P signal processing device.

FIG. 14 is a timing chart of each unit in a case where a frame of image data and a frame of an output match in a conventional 420P signal processing apparatus.

FIG. 15 is a timing chart of each unit when a frame of image data does not match an output frame in a conventional 420P signal processing apparatus.

[Explanation of symbols]

 2 Frame detection means for image data 3 Transmission frame detection means 4 Judgment means 5 Conversion means 7 Separation means 8 First signal creation means 9 Second signal creation means 21 Flag insertion means 22 Flag detection means 23 Color difference signal interpolation means 24 Switching means

Claims (6)

[Claims] 1. An image frame detecting means for detecting whether a frame of image data of a 420P signal to be transmitted is an odd frame or an even frame, and a frame of a synchronization signal to be transmitted is an odd frame or an even frame. Transmission frame detection means for detecting whether or not the frame of the image data output from the image frame detection means matches the frame of the transmission frame detection means; and A conversion unit that outputs the image data as it is as a 420P signal when they match, and outputs only a luminance signal as a 420P signal in which a main signal and a sub signal are interchanged when they do not match, . 2. An apparatus for receiving a 420P signal transmitted by the 420P signal processing apparatus according to claim 1 and converting the 420P signal into a 422P signal or an 844 signal, wherein the color difference signal component of the 420P signal is separated and copied as it is. A 420P signal processing device, wherein the signal is a color difference signal on the sub signal side. 3. An image frame detecting means for detecting whether a frame of image data of a 420P signal to be transmitted is an odd frame or an even frame, and a frame of a synchronization signal to be transmitted is an odd frame or an even frame. Transmission frame detection means for detecting whether or not the frame of the image data output from the image frame detection means and the frame of the transmission frame detection means match, the result of the determination means Match frame /
42 having flag insertion means for inserting a mismatch flag
A processing device for the 0P signal. 4. An apparatus for receiving a 420P signal transmitted by the apparatus for processing a 420P signal according to claim 3 and converting the received signal into a 422P signal or a 844 signal, comprising: a flag detecting means for detecting a flag; A color difference signal interpolating unit for separating and interpolating the transmitted first color difference signal to generate a second color difference signal; and a color difference signal of the frame when the detected flags match each other is a first color difference signal. Is a color difference signal on the main signal side, and a second color difference signal is a color difference signal on the sub signal side. The luminance signal corresponds to the main signal, the sub signal corresponds to the sub signal, and the frame in which the flag is detected as mismatched. The first color difference signal is a color difference signal on the sub signal side, the second color difference signal is a color difference signal on the main signal side, the luminance signal is a main signal corresponding to the sub signal, and the sub signal is a main signal. A processing device for 420P signals, comprising: conversion means for making the signals correspond to the signals. 5. An image frame detecting means for detecting whether a frame of image data of a 420P signal to be transmitted is an odd frame or an even frame, and a frame of a synchronization signal to be transmitted is an odd frame or an even frame. Transmission frame detection means for detecting whether or not the frame of the image data output from the image frame detection means and the frame of the transmission frame detection means coincide with each other; A conversion unit that outputs the image data as it is as a 420P signal when they match, and replaces the main signal and the sub-signal only for the luminance signal when they do not match, and outputs the color difference signal as it is as a 420P signal; Means for inserting a frame match / mismatch flag resulting from the means. Processing equipment. 6. An apparatus for receiving a 420P signal transmitted by the apparatus for processing a 420P signal according to claim 3, and converting the received signal into a 422P signal or a 844 signal. A color difference signal interpolating unit that separates and interpolates the transmitted first color difference signal to generate a second color difference signal, and a frame detected as a match by the flag detection unit converts the first color difference signal into a main signal side. The second color difference signal and the second color difference signal are used as color difference signals on the sub-signal side, and the frames determined to be inconsistent by the detection means use the first color difference signal as the color difference signal on the sub-signal side and the second color difference signal on the main signal side. And a conversion means for converting the color difference signal into a color difference signal.