JPS6057794A - Scanning converter - Google Patents

Abstract

PURPOSE:To simplify the constitution by applying time division multiplex to two color difference signals in demodulating a carrier chrominance signal so as to decrease the number of time axis converting circuit. CONSTITUTION:An NTSC signal AD-converted by an AD converting circuit 16 is separated into a luminance signal Y and a carrier chrominance signal C at a Y/C separating circuit 1, and after the chrominance signal C is demodulated into two color difference signals at a color demodulation/demultiplex circuit 2, the signal is outputted to an interpolation circuit 4 as a signal CRB subject to time division multiplex in one system. The interpolation circuit 4 forms an interpolation signal to interpolate the signal between the interlace scanning lines from the luminance signal Y and the color difference signal CRB and outputs the signal to the time axis converting circuits 3a, 3b. Then a matrix circuit 5 generates three primary color signals R, G and B and outputs the signals to a high resolution monitor via D/A converting circuits 6a, 6b and 6c.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention converts a supplied interlaced color television signal into a progressive scan color television signal and converts it into a progressive scan color television signal. The present invention relates to a scan conversion device that displays high-quality images on a high-resolution monitor.

Color television gene signal of the current interlacing system (hereinafter referred to as 1)
The JTsc signal (abbreviated as "JTsc signal") suffers from deterioration in image quality due to the composite signal, as well as cross color, dot crawl interference, and a reduction in resolution due to percent separation.

Further, image quality deterioration due to interlaced scanning (hereinafter abbreviated as ink-lacing) includes noticeable line flickers, bearings, and scanning gland defects.

One method for removing these disturbances is to apply scan conversion processing to a signal of 525 lines and 22 l increments, thereby converting it into a television signal of sequential scanning of 525 lines per frame and displaying it.

Conventionally, the one shown in FIG. 1 is well known as a scan converter for converting an NT8C signal into a progressive scanning system.

The method shown in Fig. 1 consists of 147I, % conversion circuit 16% separation circuit 1, R-G@B conversion circuit 30, and time axis conversion circuit 3.
at 3 be 30 N') 1 conversion circuit 6 am
A tail consisting of 6 be 6 c. N'rSC(lt) The signal given after % conversion is divided into a luminance signal Y and a carrier color signal C in a % separation circuit l [tL, R-G-B
The conversion circuit 30 obtains red (2), 9 green, 0, and 2 signals by a matrix from the luminance signal Y and the carrier color signal C, and generates each interpolation signal (Rb, Gb, Bb) to the time axis conversion circuit 3a.

,) % after making sequential scanning signals (R・0・B) in 3b and 3c
It is output to the monitor through 6a, 6b, and 6c.

As described above, this method has the disadvantage that the time axis converting circuit requires a total of three time axis converting circuits for 几, G, and B. The purpose of the present invention is to convert two It is an object of the present invention to provide a scan conversion device which can simplify the hardware process by requiring only two time axis conversion circuits for time-division multiplexing of color difference signals, one for a bright signal Y and one for a color difference signal.

A conversion device for converting into a digital or increment type television signal includes a separation circuit that separates the converted input NT8C signal into a luminance signal and a carrier color signal, and a signal obtained by recovering the carrier color signal. a color demodulation/multiplexing circuit that time-division multiplexes two color difference signals into one system; an interpolation circuit that uses the multiplexed color difference signal to obtain an interpolation signal for compensating between interlaced scanning lines; a multiplexed color difference signal; ! A scan conversion device is obtained, comprising: a time axis conversion circuit for obtaining a multiplexed color difference signal subjected to scanning interpolation from an interpolated signal;

Next, the present invention will be explained in detail. After converting the input signal into
Obtain B-Y. These two color difference signals are −Y,・B Y
x・几−Y、・13 Yx” ”−Yass' B−
Yass is time-division multiplexed into one system, and the color difference signal Cns matches the number of samples of one line of the luminance signal Y.
Create. As a result, only two time axis conversion circuits are required for the color difference signal Cnn)1jζ multiplexed with the luminance signal Y.

Next, a block diagram of a specific example is shown in FIG.

The configuration includes a yD conversion circuit 16, a k separation circuit 11, a color demodulation/multiplexing circuit 2, an interpolation circuit 4, and a time axis conversion circuit 3m.

It consists of a 3BS straight line circuit 29, a matrix circuit 5, and % conversion circuits 6a, 61), and 6c. Subcarrier (
f, T to the input that is % converted with a sampling frequency of 3° and 4 times
The IC signal is separated into a luminance signal Y and a carrier color signal C in a percentage separation circuit 1.

The separated carrier color signal C is demodulated into two color difference signals in the color tone/multiplexing circuit 2, and then outputted to the next stage interpolation circuit 4 as a signal CRB time-division multiplexed into one system. Note that the portion composed of the % separation circuit 11, the color demodulation multiplexing circuit 2, and the interpolation circuit 4 will be referred to as a % separation demodulation circuit 31 hereinafter. In the interpolation circuit 4, the input luminance signal Y and the multiplexed color difference signal C! An interpolation signal is created for the luminance signal Y and the color difference signal CRB to compensate for the gap between scan lines of increments necessary when changing from LB to j-order scanning. Thereafter, the luminance signal Y of the original signal, the multiplexed color difference signal CnB, and the luminance signal Y' of the interpolation signal and the multiplexed color difference signal CRB' are output to the time axis conversion circuits 3a and 3b. Time d,'di? ;: The control circuits 3a and 3b store the signal in the line memory at 4fsc.
After writing at a clock frequency of 8 fBc, conversion is made to sequential scanning by switching between the original signal and the interpolation signal read at a speed of 8 fBc. Further, the color difference signal CJ that has been subjected to the rigid transition conversion is divided into the original two color difference signals by the linear conversion circuit 29.
The obtained class, dust→)° sample and υ, can be interpolated within the range by adding the sample and dividing by 2. As a result, the number of samples of the luminance signal Yx and the two color difference signals R-Y and B-Y match, the matrix is shifted by the matrix circuit 5 at the next stage, and the three primary color signals G and B are generated. and%
Sent to transfer devices 6a, 6b and 6c, respectively
B"i and output to a high-resolution monitor.

FIG. 3 shows an example of the % separation demodulation circuit 31. As described above, the k-separation demodulation circuit 31 demodulates the luminance signal Y (!: separated into carrier color signal C, carrier color signal C and p color difference signal) L, -Y, B-Y signals using a comb filter. , time-division multiplexed and output, and interpolation data necessary for one prefecture scan is created for the color difference signal multiplexed with the luminance signal Y.

First, the % separation circuit l will be explained. The composition is a line memo! I 7a, 7b, band pass filter (hereinafter 1
'BPF) 8, a control section 9, an adder 10, and a subtracter 11.

Now, when the signal 51 obtained by converting the NTSC signal into % is input, the control signal 55 from the control section 9 is input to the first line memory 7a.
The signal is stored as a signal 52 delayed by one line and is supplied to the next stage line memory 7b and the subtracter 11.

Here, the control signal 55 consists of a write signal to the line memory, a read signal, and a signal indicating the address of both. The line memory 7b operates according to the control signal 55 from the control section 9, and outputs a signal 53 delayed by one line. In other words, the signal 53 is delayed by two lines with respect to the input 51. The adder 10 has a coefficient of 2=-"7.
Input the multiplied signal 59.

Further, a signal 101 obtained by multiplying the coefficient by 3=-% is input to the input 51 to the adder IO. The coefficient 1=-% signal 100 is input to the signal 52 to the other. The increase result becomes a signal 54 and is supplied to the BPF 8. In other words, this constitutes a comb filter. B P F 8 is a generally known Reintal bandpass filter, and the carrier color signal C is concentrated by the clock 56 of the control section 9).
It has the characteristic of passing only around 8 NHZ, and the output of the HPFa is obtained as a carrier spacer 58. The subtracter 11 obtains a luminance signal 57 by subtracting the carrier color number 58 from the signal 52 containing the luminance signal and the carrier color signal.

As described above, the a*vtit= signal and the carrier color signal are separated. The separated carrier color signal 58 is outputted by the color route multiplexing circuit 2 at the next stage.

The color demodulation/multiplexing circuit 2 is composed of a multiplexer 13. The input conveyance color 1β number 58 is input to one side of the multiplexer 13, and is multiplied by the coefficient 1K4=-1 to obtain the negative value of color difference ID number d -Y・B -Y (=(几-Y
), -CB-Y) is obtained on the juice signal +@6Q and inputted to the other side of the multiplexer 13.

The multiplexer 13 receives the select signal 64 from the control unit 9.
The positive and negative values of the color difference signals R-Y and B-Y are switched and time-division multiplexed to obtain a multiplexed color difference signal 61 of R-Y and B-Y, which is output to the interpolation circuit 4 at the next stage.

FIG. 4 is a waveform diagram for explaining the operation of the color demodulation/multiplexing circuit 2. In FIG.

In the figure, 200 is the R-Y signal 1300 modulated by the subcarrier.
indicates a B-Y signal modulated by a subcarrier.

A waveform obtained by adding waveform 200 and waveform 300 is input to color demodulation/multiplexing circuit 2 . The RY and B-Y signals are each modulated by subcarriers with a 90° phase difference. Therefore, the sampling frequency is set to 4 fsc
If the sampling phase is locked to the subcarrier, the sampling time will be the time indicated by the dotted line in the figure, and the color control/multiplexing circuit 2 will receive (R-
The signals Y), CB-Y), -(RY), -CB-Y) are input. Therefore, the color demodulation/multiplexing circuit described with reference to FIG. 3 can demodulate and multiplex the 9s carrier color signal.

Interpolator 4 has two field memos IJ 14a and 1
The input brightness i@ signal 57 and multiple color difference signal 61 are input to the field memories 14a and 14b, respectively, and stored in accordance with the signal 65 of the control unit 9, and become delayed signals 66 and 67 for l fields during sequential scanning. As the original signal of the interpolated signal 57. ．． 61 and is output to the next stage time 1i'J switching circuit 3.

FIG. 5 is a block diagram showing an example of the time axis conversion circuits a, 3b, the matrix circuit 5, and the straight line conversion circuit 29.

The time axis conversion circuits 3a, 31) simultaneously write the input original signal and interpolation signal into the line memory at 4 fsc, and
Gino primary scanning is made possible by switching between the readout original signal and the interpolation signal using fsc. Time axis conversion circuit 3
Since the operations of a and 3b are the same, only 3a will be explained now. As for the configuration, line memory '7m, 17bs
Multiplexer 18a1 is the control section 19a.

The original signal 66 and interpolated signal 57 are each line memo! J17a
.

17b and is stored at 4 fsc according to the signal 71 from the control section 19a. The signal 105 is read out at twice the speed of 8 fsC, and the signals 68 and 69 whose time bases are compressed are input to the multiplexer 183. The multiplexer 18a alternately switches between the original signal 68 which has been time-base compressed and the interpolation signal 69 every 5i lines using the signal 70, and outputs the signal 72 for sequential scanning (75 for the color difference signal) to the matrix circuit 5 at the next stage. .

A waveform diagram of time axis conversion is shown in FIG.

The numbers inside 0 in the figure represent the numbers of scanning lines.

In the straight line circuit 29, the luminance signal Y is 910 samples/line, while the multiplexed color difference signal is R-Y, B-
Each Y has 455 samples/line.

Therefore, after separating the multiplexed 几-Y and B-Y, they are separated in a straight line.

The configuration is a control unit 20, a register 12#23121
a.

21b1 adder 25a, 25 multiplexer 22a.

It consists of 22b. According to the input multiplexed signal 75i and signals 8Q and 81 from the control unit 20, set R-Y in register 12 and B-Y in register B, and output R-Y signal 8.
2 and a BY signal 83, respectively. Next, since the interpolation circuit of R-Y and the interpolation circuit of B-Y are the same circuit, R-Y will be explained. Insert the signal 82 into one input of the adder 25a and send the Y signal 82 to the single-stage register 21a.
Put the delayed signal lR into the other input and calculate the sum.
It is output to one side of the multiplexer 22a. The multiplexer 22a alternately switches the signals lR and (84) to obtain h'.
The signal has 910 samples per line and is sent to the next stage)
It is output to the IJx circuit 5. The B-y<= number is also output in the same way.

FIG. 7 shows a sample unit diagram.

In the same figure, Circles indicate original samples, and double circles indicate interpolated samples.

The matrix circuit 5 outputs a luminance signal Y and color difference signals RY, B.
The following matrix is taken from -Y to obtain RGB three primary color signals.

The configuration includes limiters 24a, 24b, 24c, 1 adders 26B, 26b, 26C% subtracters 27, 28.

Next, the It-G-'B signal is matrixed.

The brightness signal 79 is sent to the adder 26a, where it is added to the luminance signal 72 and lR'(R
-Y) manually and take the phase. First, the G signal 94 is obtained by subtracting a signal 89 obtained by multiplying lR'(a-y) by a coefficient of 5 (K5=) from the corridor signal 72 in the subtracter 27.
Enter 1 into the subtractor A.

Next, in the adder 26b, a signal 103 obtained by multiplying the coefficient by □=-X and a signal obtained by multiplying the coefficient by 7:% are added to form a signal 104, which is input to the subtracter section. In other words, the signal 104 becomes Vss di (B-y).

The subtractor % subtracts signal 104 from signal 91.

The B signal 96 is sent to the adder 26C with the jjFff signal 72 and II
All you have to do is input B'(B-Y) and calculate the sum.

After that, the calculation result for R79/G94-R96 is 10 bits.
Limiter 2' a e 24 b +
Convert to 8bit through 24c, R97/098
- Output as R99.

The R and -G@B signals output from the matrix circuit 5 are each converted at 9/A6 and output to a high resolution monitor.

Furthermore, although the first embodiment describes the case of a progressive scanning system, it goes without saying that the present invention can also be applied to an interlaced scanning system.

That is, by interpolating the corresponding signal between the scanning lines of the signal converted to the progressive scanning method obtained in the first embodiment, the obtained interpolated signal and the signal converted by the sequential scanning method are used. If you switch it for each frame, you can use sequential scanning.
An interlaced scanning signal having twice the number of scanning lines is obtained.

As described above, according to the present invention, two color difference signals when demodulating a carrier color signal are time-division multiplexed to treat them as a multiplexed color difference signal of the Lou system. It is possible to provide a scan conversion device that requires only two multiplexed color difference signals and has simple hardware. Further, although the above description has been made regarding the case where N=2, it can also be applied to a progressive scanning method or an interlaced scanning method when N≧3.

[Brief explanation of the drawing]

Figure 1 is a block diagram for explaining the conventional method; Figure 2 is a block diagram for explaining the present invention in detail; Figures 3 and 5 are for explaining the embodiment of the present invention in more detail. FIG. 4 is a waveform diagram to clarify the operation of the color demodulation/multiplexing circuit used in the present invention, and FIG. The waveform diagram shown in FIG. 7 is FIG. 9 for explaining the operation of the linear interpolation circuit used in the present invention. In the figure, 1... Separation circuit, 2... Color demodulation/multiplexing circuit, 3a, 3b, 3c... Time axis f supply circuit, 4...・Interpolation circuit, 5...Ma) IJ
Fuchs path, 6a, 6b, ct, Converter, 16...56 converter, 29... Straight line circuit, 3X)...R・(
1.13 Meal replacement circuit, 31...% separation demodulation circuit.

Claims (1)

[Claims] In a conversion device that converts an input interlaced scanning color television signal into a progressive scanning or interlaced scanning television signal with horizontal scanning and W*a being approximately N times (N is an integer of 2 or more), A four-separation circuit separates the input interlaced scanning color TV gene signal converted into a luminance signal and a carrier chrominance signal, and time-division multiplexes the two color difference signals obtained by demodulating the carrier chrominance into one system. A color demodulation/multiplexing circuit, an interpolation circuit that uses the multiplexed color difference signal to obtain an interpolation signal for compensating between scan strings in interlaced scanning, and a multiplexer in which scanning line interpolation is performed from the multiplexed color difference signal and the interpolation signal. A scan conversion device characterized by being equipped with a time 111!1 conversion circuit for obtaining color difference signals◎