JPH0771265B2 - Scan line interpolation method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning line interpolation method for converting an interlaced signal into a non-interlaced signal on the receiving side.

[Conventional technology]

First, with respect to the above technique, a conventionally proposed scanning line interpolation auxiliary signal (hereinafter referred to as “auxiliary signal”) will be briefly described.

FIG. 2 (a) is a diagram showing scanning lines thinned out on the transmission side. The horizontal axis shows time, and the vertical axis shows the positional relationship when a 1-field screen scanning line is viewed from the side. Scanning lines to be transmitted, circles are scanning lines to be thinned out, and scanning lines to be transmitted as an interlace signal are as shown in FIG. 2 (b).

In the prior art, an auxiliary signal containing information for reproducing the thinned scanning line on the receiving side is multiplexed with a predetermined portion of the interlaced signal and transmitted.

Next, the information of the auxiliary signal will be described.

Information for reproducing scan line B to be thinned out is determined by calculating _{X B = 1/2 (-A} + 2B-C) = B- (A + C) / 2 of the formula: further band-limited frequency band to 1MHz The obtained signal is sent as an auxiliary signal LD (Line Differential).

Since this auxiliary signal LD has a horizontal frequency component of 1 MHz or less, it can be expressed as LDL = BL- (AL + CL) / 2.

FIG. 3 is a block diagram of a scanning line interpolation circuit using a conventional scanning line interpolation method. In the figure, 1 is an input terminal to which the transmitted interlaced signal is input, 2 is a 1H delay circuit, 3 is an adder, 4 is a 1/2 multiplier, 5 is an adder, and 6 is LP.
F and 7 are the output terminals of the interpolation scanning line signal.

Next, the operation will be described.

Now, assuming that the scanning line to be interpolated is B in FIG. 2, the information of the scanning line C is input to the input terminal 1,
The output of the 1H delay circuit 2 becomes the information of the scanning line A. The information of the scanning lines A and B is added in the adder 3 to become the information of A + C, and is multiplied by 1/2 in the 1/2 multiplier 4 to become the information of (A + C) / 2. Signal LD is added and signal X1
Becomes This signal X1 is X1 = {(A + C) / 2} + LDL = {(AL + AH) + (CL + CH)} + BL-{(AL + CL) /
2} = BL + {(AH + CH)} However, the subscript H is a horizontal high frequency wave component, and L is a horizontal low frequency component.

In this signal X1, the horizontal high frequency wave number component is removed by the LPF 6, and only the horizontal low frequency component BL is output to the output terminal 7.

[Problems to be Solved by the Invention]

The conventional scanning line interpolation method has a problem that the interpolated scanning line signal reproduced on the receiving side includes only the horizontal low frequency components of the original scanning line signal.

The present invention has been made to solve the above problems, and a scanning line interpolation method capable of reproducing an interpolated scanning line signal that also includes a signal component approximate to the horizontal high frequency component of the original scanning line signal. Aim to get.

[Means for Solving the Problems]

According to the present invention, the scanning line signals located above and below the scanning line to be interpolated and the scanning line signal one field before the scanning line to be interpolated are determined based on the motion information detected on the receiving side. And a horizontal high frequency component extracted from these added signals and a horizontal low frequency component obtained from the scanning line interpolation auxiliary signal are added to obtain an interpolated scanning line signal.

[Action]

According to the present invention, a horizontal low frequency component of a scan line to be interpolated is obtained from an auxiliary signal transmitted together with an interlaced signal, and a scan to be interpolated using motion information detected on the receiving side. The horizontal high frequency component of the scanning line to be interpolated is obtained from the signals of the scanning lines located above and below the line and the scanning line signal one field before the scanning line to be interpolated, and these horizontal frequency components are added. Since the scanning line signal to be interpolated is obtained, the interpolating scanning line signal having information close to the original scanning line signal is obtained.

〔Example〕

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

FIG. 1 is a block diagram of a scanning line interpolation circuit using a scanning line interpolation method according to an embodiment of the present invention. The same reference numerals as those in FIG. 3 indicate the same or corresponding portions, and they operate similarly. Therefore, description of those parts will be omitted.

In the figure, 8 is a 263H delay circuit, 9 is a MIX circuit, and 10 is a HP.
F and 11 are adders, and 12 is a motion information detection circuit.

Next, the operation will be described. Now, assuming that the signal of the scanning line C of the interlaced signal is input to the input terminal 1, 263H
The output signal of the delay circuit 8 is 1 of the scanning line B to be interpolated.
It is a signal of the scanning line D before the field and includes a horizontal high frequency component DH and a horizontal low frequency component DL. The signal of the scanning line D and the output signal (A + C) / 2 of the 1/2 multiplier 4 are input to the MIX circuit 9.

On the other hand, the motion information detection circuit 12 compares the signals of the surrounding scanning lines to detect how much the moving image of the scanning line B to be interpolated, and in the case of a complete still image, α = 0 complete In the case of a moving image, “motion adaptive coefficient α”, which is real number information of 0 ≦ α ≦ 1.0 where α = 1.0 is output.

As the motion information detection circuit 12, various types have been known in the related art, and thus detailed description thereof will be omitted.

The motion adaptive coefficient α is also input to the MIX circuit 9, the following calculation is performed, and the signal X2 is output.

X2 = α {(A + C) / 2} + (1-α)  (DH + DL) This signal X2 is input to the HPF10, and the signal XH from which the horizontal low frequency components have been removed is output. The horizontal frequency component of this signal XH is as follows.

XH = α · {(AH + CH) / 2} + (1-α) · DH This signal XH and the output signal BL of LPF6 are added by the adder 11, and = XH + BL = α · {(AH + CH) / 2} + ( 1-α) ・ DH +
A signal having a horizontal frequency component of BL is output to the output terminal 7.

This signal always includes the horizontal low frequency component BL of the scanning line B to be interpolated, which is the same as the conventional example. For example, the scanning line B to be interpolated is completely still image. In the case of the section, since α = 0, = DH + BL, and the horizontal high frequency component of the scanning line D includes the horizontal high frequency component DH of the scanning line D.

Further, if the scanning line B to be interpolated is completely a moving image part, α = 1.0, and therefore = {(AH + CH) / 2} + BL. It is replaced by the average of the horizontal high frequency components AH and CH of the scanning lines A and C.

Strictly speaking, if the scanning line B is a completely moving image portion, the horizontal high frequency component of the scanning line B does not exist, but the above (AH + CH) / 2
Gives a signal relatively close to it, so
A signal having information closer to the original scan line B than that of only BL can be obtained.

〔The invention's effect〕

As described above, according to the present invention, the scanning line signals located above and below the scanning line to be interpolated and the scanning line signal one field before the scanning line to be interpolated are detected by the receiving side. Multiply the coefficient determined based on the information, and add the horizontal high frequency component extracted from these added signals and the horizontal high frequency component obtained from the scanning line interpolation auxiliary signal to obtain an interpolated scanning signal. With this configuration, there is an effect that an interpolated scanning line signal having image information close to the original scanning line B thinned out at the time of transmission can be obtained.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, FIG. 2 is a diagram showing a scanning line structure for explaining scanning line thinning-out and interpolation processing, and FIG. 3 is a conventional scanning line interpolation circuit. It is a block diagram. In the figure, 2 is a 1H delay circuit, 3, 5, 11 are adders, and 4 is 1 /
2 multiplier, 6 LPF, 8 263H delay circuit, 9 MIX circuit, 1
Reference numeral 0 is an HPF, and 12 is a motion information detection circuit. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A scanning line interpolation method for converting an interlaced signal in which an auxiliary signal for scanning line interpolation including horizontal low frequency component information of thinned scanning lines is converted into a non-interlaced signal, at least interpolation is performed. The scanning line signals located above and below the scanning line to be interpolated and the scanning line signal one field before the scanning line to be interpolated are multiplied by a coefficient determined based on the motion information detected on the receiving side. Scanning line characterized by adding the horizontal high-frequency component extracted from the addition signal and the horizontal low-frequency component obtained from the scanning-line interpolation auxiliary signal to obtain an interpolated scanning line signal. Interpolation method.