JPH0275290A - Scanning number converter - Google Patents

Abstract

PURPOSE:To convert the number of scanning lines inexpensively by supplying an interpolation location signal to two multipliers and a memory controller from an interpolation position signal generator and controlling the weighting addition or memory address generation so that a prescribed scanning line number is converted. CONSTITUTION:An interpolation position signal (e) is supplied from an interpolation position signal generator 7 to 1st and 2nd multipliers 4, 5 applying weight multiplication to two adjacent scanning line signals of a television signal and a memory controller 2 controlling write/readout of a field memory 1 and a line memory 3. Then weight addition or memory address generation is controlled so as to convert a prescribed scanning line number. Thus, the scanning line number is converted inexpensively by using the field memory 1 having a capacity to able to store the scanning line signals by nearly one field or the television signals.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scanning line number conversion device used in a television format conversion device that performs mutual conversion between television formats having different numbers of scanning lines per frame and field frequencies. This is especially effective when performing simple format conversion in consumer video equipment, such as video tape recorders (VTRs).

2. Description of the Related Art A device for converting a certain television signal into a television signal of another system having a different number of scanning lines per frame and a different field frequency is conventionally known as a television system converter (for example, Japanese Patent Publication No. 53-31 .572 Publication @NTSC-PAL system converter”, 1986-I
NHK Giken Monthly Report P, 20-P.

28 etc.). This conventional equipment is used at broadcasting stations, so the converted signal must also satisfy the strict standards of each television signal, and it also prevents unnatural movements. Because of the strict requirements, complex processing such as motion compensation is performed using several fields of memory.

Problems to be Solved by the Invention Even in general consumer video equipment, for example, if television signal format conversion is applied to a video tape recorder (VTR), a television receiver (TV) that is compatible with only one format can be used. Even if there is PAL.

Tapes recorded in either NTSC or SECAM format can be played back and displayed, making them highly valuable. However, conventional conversion methods have had the problem of being extremely expensive and cannot be used as consumer video equipment.

The present invention solves the above-mentioned problem, and aims to provide a simple and inexpensive scanning line number conversion device using a memory having a capacity to store one field of a television signal. be.

Means for Solving the Problems In order to solve the above problems, the present invention converts a first television signal into a second television signal having a different number of scanning lines per frame.
A scanning line number conversion device for a television signal that converts the television signal into a television signal, the field memory having a capacity capable of storing one field of the television signal, and a field memory capable of storing one scanning line of the television signal. A line memory having a capacity, first and second multipliers that perform weighted multiplication on each of two adjacent scanning line signals of a television signal, and adding the outputs of the first and second multipliers to generate a scanning line an adder that outputs an interpolation signal; and an adder that calculates a position between two adjacent scanning line signals of the television signal to place the scanning line interpolation signal of the adder, and outputs an interpolation position signal representing the interpolation position. an interpolation position signal generator; and a memory controller for controlling writing and reading of the field memory and the line memory; It is configured to convert a predetermined number of scanning lines by supplying an interpolation position signal.

Operation With the above configuration, the interpolation position signal generator calculates where the scanning line interpolation signal of the output television signal is located between two adjacent scanning line signals of the input television signal, and calculates the calculated interpolation signal. A position signal is output to the first and second multipliers and a memory controller, and the memory controller controls the memory addresses of the field memory and line memory according to the interpolated position signal, and outputs the position signal to the first and second multipliers. performs weighted multiplication on each adjacent scanning line signal of the input television signal, and adds the outputs of these first and second multipliers in an adder to perform scanning line interpolation of a predetermined television signal to be output. I get a signal.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 1(a) and 1(b) are block diagrams showing the configuration of a scanning line number converter according to an embodiment of the present invention. The number is 525 and the field frequency is 60Hz) to 62
A block diagram showing the configuration in the case of conversion to a 5.50 format signal (the number of scanning lines per frame is 625 and the field frequency is 50H2), and FIG. 60 is a block diagram showing a case of conversion to a V.60 system signal.

Figures 1 (a) and (b) Nioite, 1i, t525.
This field memory is capable of storing 262.5 scanning line signals corresponding to one field of a 60 format signal, and the scanning line signals (data) of the field memory 1 are addressed by a memory controller 2, which will be described later. In FIG. 1(a), data is written at a field frequency of 60 Hz and read out at a field frequency of 50 Hz.
In bl, data is written with a field frequency of 50 Hz and read out with a field frequency of 60 Hz. 3 delays the storage capacity of one scanning line signal by one horizontal scanning period. 4.5 is the adjacent 2 by line memory 3
The first and second multipliers to which the scanning line flaw signal is input, each perform weighted multiplication by one scanning line flaw signal,
The respective output signals are added by an adder 6 and a scanning line interpolation signal is output. 7 is an interpolation position signal generator, in order to convert the number of scanning lines into the number of scanning lines of the 525.60 system signal and the 625.50 system signal, the input adjacent two
Calculates where a predetermined scanning line interpolation signal to be output is located between the scanning line flaws, and sends the calculated interpolated position signal to the first and second multipliers 4 and 5 and the memory controller 2;
Output according to field frequency. Based on this interpolated position signal, the memory control unit 2
Memory address operations are performed in the field memory 1 and line memory 2, and the first and second multipliers 4.5 determine weights to be multiplied and perform weighted multiplication. 8.9 is a signal input terminal, and 10.1.1 is a signal output terminal.

The operation of the scanning line number conversion device configured as described above will be described below.

First, with reference to Figure 1 (at) and Figure 2, 525.6
Conversion from the 0 system to the 525.50 system will be explained.

Figure 1 (in al, the signal input terminal 8 has a 525°6
0 system signal a comes in. This 525.60 system signal a
is written into the field memory 1 by address operation by the memory controller 2 field by field, and at the same time, the scanning line signal stored in the field memory 1 is the interpolation position signal e supplied from the interpolation position signal generator 7, and the field frequency is The address is operated by the memory controller 2 and read out so that the value becomes 50H2. The line memory 3 delays one scanning line flaw signal f supplied from the field memory 1 by one horizontal scanning period and supplies it to the first multiplier 4 . In the first multiplier 4 and the second multiplier 5, an interpolated position signal generator 7
The scanning line conversion signal g supplied from the line memory 3 and the one scanning line flaw signal f supplied from the field memory 1 are subjected to weighted multiplication using the interpolated position signal e supplied from the field memory 1, respectively. In the adder 6, the first and second multipliers 4
．． The two conversion signals of 5 and j are added, and the scanning line interpolation signal b
, that is, outputs a 625.50 system signal to the signal output terminal 10.

FIG. 2 shows how scanning lines are converted when converting from the 525.60 system to the 625.50 system.

In FIG. 2, the solid line on the left shows the scanning line signal of the 525.60 system signal, and the solid line on the right shows the scanning line signal of the 625.50 system signal. For example, when creating a scanning line of b2 line by scanning line conversion, a
One scanning line flaw signal f of three lines is read out and stored in line memory 3.
The scanning line conversion signal g of line a2 is read out from.

In addition, the interpolation position signal generator 7 calculates the distance between the 12-b22 line (-
L1/(L1+L2)), thereby outputting an interpolated position signal e representing a
The scanning line signals of the 2nd line and the a3 line are multiplied with a weight inversely proportional to the distance from the b2 line, and the adder 6 performs the addition and outputs the result as a scanning line interpolation signal b2. By the way, bl, b2. b3. For lines b4 and b6, one scanning line flaw signal f is read out from field memory 1 using a line address in which the address in the line direction is increased by 1 every horizontal scanning period, and from line memory 3, one horizontal scanning period is read out. Scanning line interpolation can be performed by reading out the previous scanning line conversion signal g. However, when creating the scanning line of the b5 line, the signal of the a5 line is read out twice from the field memory 1, and when the signal of the a5 line is first read out from the field memory 1, the signal is read out from the field memory 1 twice. It is necessary to prohibit writing to the line memory 3 so that it is not written to the memory 3. In order to cause the field memory 1 and the line memory 3 to perform the above operations, in this embodiment, the memory controller 2 controls the memory address using the interpolation position signal e output from the interpolation position signal generator 7. There is. In other words, bl, b2.
b3.

b4. , when interpolating scanning lines such as line b6, the value (Ll) of the interpolation position signal e decreases every horizontal scanning period, as shown in FIG. On the contrary, when the value (Ll) is interpolated, the value (Ll) increases, so the memory controller 2 detects this and performs the above-mentioned memory control.

Next, with reference to Figure 1 (bl and Figure 3), 625.50
The conversion from the 525.60 system to the 525.60 system will be explained.

The basic operation can be considered similar to the case of conversion from 525.60 system to 625.50 system.

The difference is that, as shown in FIG. The number is 625.50
The scanning line interpolation signal is written in a form that is reduced from 312.5 lines of the scheme signal to 262.5 lines of the 525°60 scheme signal.

FIG. 3 shows how the number of scanning lines is converted at this time.

In FIG. 3, the solid line on the left shows the scanning line signal of the 625.50 system signal, and the signal on the right shows the scanning line signal of the 525.60 system signal. When the C2 line signal is input to the signal input terminal 11, the C1 line signal is input from the line memory 3.
Line signals are read out, and these two lines are weighted and added together by a first multiplier 4, a second multiplier 5, and an adder 6 to create a d1 line. The signal input terminal 11 has a C
2, C3, C/4 line signals come in sequentially dl
, d2 and d3 line signals are created. However, when the C5 line signal comes in, there is no signal to be generated by scanning line interpolation, so writing of the signal to the field memory 1 must be prohibited at this time. This prohibition of writing signals into the field memory 1 is also performed using the interpolation position signal output from the interpolation position signal generator 7, as described above. In other words, C is connected to the signal input terminal 11.
When the signals on the I, C2, C3, and C4 lines are incoming, the third
As shown in the figure, the value (Ll) of the interpolated position signal (for example, the distance of the CI-d11 line when the C2 line comes in) increases sequentially, but when the C5 line signal comes in, the interpolated position signal (C5- Since the value (Ll) of the distance of line a44 decreases compared to the value (Ll) of the interpolated position signal (distance of line C3-d33) one horizontal scanning period ago, the memory controller 2 detects this. prohibits signal writing to field memory]. When the C6 line signal comes in, a signal representing the distance of the C3-d44 lines is output again as an interpolation position signal, but since this is the same as the interpolation position signal one horizontal scanning period ago, at this time the C5 and C6 line signals are output. The d4 line signal created by weighted addition is written into the field memory 1. The scanning line signal written in the field memory 1 is read out by the memory controller 2 so that the field frequency becomes 60 Hz.

In this way, from the interpolation position signal generator 7, the first and second
By supplying the interpolation position signal C to the multiplier 4.5 and the memory controller 2, and controlling the weighted addition or memory address generation so that a predetermined number of scanning lines is converted, approximately 1 of the television signal is Conversion of the number of scanning lines can be realized at low cost by using the field memory 1 which is large enough to store scanning line signals for fields.

In the description of this embodiment, the configuration for converting from 525.60 system to 625.50 system and 625.5 system will be explained.
The configuration for converting from the 0 system to the 525.60 system is shown in Figure 1 (al and (bl) are shown separately, but it is a single circuit in which each block is shared by switching the signal flow with a switch. Obviously, conversion in both directions is possible.

Effects of the Invention As described above, according to the present invention, the interpolation position signal is supplied from the interpolation position signal generator to the first and second multipliers and the memory controller, so that a predetermined number of scanning lines can be converted. By controlling weighted addition or memory address generation, it is possible to achieve the effect that a scanning line number conversion circuit can be realized at a low cost using a field memory that can store about one field of a television signal.

In particular, digital VTRs with built-in field memory
If the present invention is used in such applications, the field memory can be used in common with other functions, and the system can be equipped with a television signal format conversion function with a small increase in price.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are block diagrams showing the configuration of a scanning line converter according to an embodiment of the present invention, and FIGS. ] ) scan line. FIG. 3 is an explanatory diagram for explaining the operation of the conversion device. 1...Field memory, 2...Memory controller, 3
... Line memory, 4... First multiplier, 5...
Second multiplier, 6... Adder, 7... Interpolation position signal generator, 8.9... Signal input terminal, 10.11.
...Signal output terminal, a, d...-525,60 system signal, b, c...625.50 system signal, e...
Interpolated position signal.

Claims (1)

[Claims] 1. A television signal scanning line number conversion device for converting a first television signal into a second television signal having a different number of scanning lines per frame, which converts one field of the television signal into a second television signal having a different number of scanning lines per frame. a field memory having a storage capacity; a line memory having a capacity capable of storing one scanning line of a television signal; and first and second memory for performing weighted multiplication on each of two adjacent scanning line signals of the television signal. a multiplier that adds the outputs of the first and second multipliers and outputs a scanning line interpolation signal; and an adder that adds the outputs of the first and second multipliers and outputs a scanning line interpolation signal; an interpolation position signal generator that calculates a position between signals and outputs an interpolation position signal representing the interpolation position; and a memory controller that controls writing and reading of the field memory and the line memory; A scanning line number conversion device configured to supply an interpolation position signal from the interpolation position signal generator to the first and second multipliers and the memory controller to convert a predetermined number of scanning lines.