JPH01175385A - Image processor - Google Patents

Abstract

PURPOSE:To obtain the same image as that obtained by using a frame memory by using a field memory as an image memory, forming the line of a next field from the mean value of an adjacent line stored in the image memory when correlation is hard and enabling the image signal of one frame to be obtained. CONSTITUTION:By an interpolation circuit 26, the video signal of one frame is generated from the video signal of one field. That means, the video signal of the next field is obtained from the mean value of the video signal of the adjacent line when the correlation is hard. The two fields of the video signal in an identical field are successively read from the field memory 23 and the video signal of the next field is formed by mean value interpolation in the circuit 26. Thus, the same image as that obtained by using the frame memory can be obtained without using the frame memory.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image processing device suitable for use in image processing during variable speed playback of video discs and VTRs.

[Summary of the invention]

The present invention provides an image processing device suitable for image processing during variable speed playback of a video disc or VTR, which uses a field memory as an image memory used during variable speed playback.
When the correlation is strong, the next field's line is formed from the average value of the adjacent lines stored in the image memory so that one frame worth of image signal can be obtained, and the same image quality as when using frame memory can be obtained. This is how it was done.

[Conventional technology]

Video disc player or VT equipped with image memory
R is becoming more common. When a video disc player is equipped with an image memory, even when playing a video disc in which video signals are recorded at CLV (constant linear velocity),
It becomes possible to perform still image playback and variable speed playback. Also,
If a VTR is equipped with an image memory, it is possible to improve the image quality during still image playback and variable speed playback.

Most conventional video disk players and VTRs equipped with image memory are equipped with a field memory that stores one field's worth of image signals. This is because a field memory has a smaller storage capacity than a frame memory that stores one frame's worth of image signals, allowing for cost reduction and miniaturization.

Also, when performing still playback, ■ frame images (&
(If No. K is stored in the frame memory and played back as a frame still, the screen may not freeze if the screen is moving quickly. In the case of field stills, the screen will not shake.

[Problem that the invention seeks to solve]

In this way, conventional video disk players and VTRs use field memory as image memory. Therefore, only one screen of each field can be reproduced using the video signal stored in the image memory.

However, an L-field screen has half the number of scanning lines compared to a one-frame screen, so the image becomes rough. In order to obtain clear images, it is desirable to be able to reproduce image signals for each frame.

However, in order to reproduce images for each frame, a frame memory is required. As mentioned above, frame memory is more expensive than field memory.

Therefore, an object of the present invention is to provide an image processing device that can obtain an image equivalent to that obtained using a frame memory without using a frame memory.

[Means for solving problems]

The present invention includes an image memory 23 that stores one field's worth of image signals, an interpolation circuit 26 that forms the next field's image signal using the one field's worth of image signals stored in the image memory 23, and a correlation between each line. When the correlation is strong, the interpolation circuit 26 forms the line of the next field from the average value of the adjacent lines stored in the image memory 23.
This image processing device obtains one frame's worth of image signals from one field's worth of image signals stored in the interpolation circuit 26 and the next field's image signals formed by the interpolation circuit 26.

[Effect]

The field memory 23 stores l fields worth of video signals. The interpolation circuit 26 generates one frame's worth of video signals from the one field's worth of video signals stored in the field memory 23.

That is, if the correlation is strong, the video signal of the next field can be obtained from the average value of the video signals of adjacent lines. Two fields of video signals of the same field are successively read out from the field memory 23. Interpolation circuit 26
The video signal of the next field is formed by mean value interpolation.

〔Example〕

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

FIG. 2 shows an embodiment in which the present invention is applied to a video disc player. In FIG. 2, 1 is a video disc. A video signal is FM modulated and recorded on the video disc 1. A video disc l is rotated by a spindle motor 2.

A video signal recorded on the video disc 1 is reproduced by an optical pink-up 3. optical pickup 3
is provided with a servo circuit 4 that performs servo of the optical system such as focus servo, tracking servo, thread servo, and skew servo. The optical pickup 3 is sent in the radial direction of the video disc 1 by a slider motor 5.

A drive signal for the slider motor 5 is supplied via a motor dryer 6.

The signal reproduced by the optical pickup 3 undergoes frequency correction via the RF amplifier 7 and is supplied to the video demodulation circuit 8 . A video demodulation circuit 8 performs FM demodulation on the video signal.

Further, dropout correction is performed in this video signal demodulation circuit 8. The video signal output from the video demodulation circuit 8 is supplied to the TBC circuit 9, and the synchronization separation circuit 10
is supplied to

A synchronization separation circuit 10 separates the horizontal synchronization signal in the reproduced video signal. This horizontal synchronization signal is supplied to the phase comparator circuit 11. The phase comparison circuit 11 includes a reference signal generation circuit 1.
A reference signal is supplied from 2.

The phase comparison circuit 11 compares the phase of the reproduced video signal output from the sync separation circuit 10 and the phase of the reference signal output from the reference signal generation circuit 12. This phase error signal is supplied from the phase comparison circuit 11 to the motor driver 13, and the rotation of the spindle motor 2 is controlled by the output of the motor driver 13. This allows video disc 1
The jitter component in the reproduced signal is removed.

The TBC circuit 9 removes time axis fluctuation components contained in the reproduced video signal. The TBC circuit 9 is C
Consists of an analog delay circuit using CD, VC01
It is driven by a drive signal from 8 (voltage controlled oscillator). The output of the TBC circuit 9 is supplied to a burst shaping circuit 14 and also to a synchronous separation circuit 15. The output of the burst shaping circuit 14 and the output of the sync separation circuit 15 are supplied to a burst extraction circuit 16. A burst a sampling circuit 16 extracts the burst signal.

This burst signal is supplied to the phase comparator circuit 17. The phase comparison circuit 17 compares the phase of the burst signal output from the burst extraction circuit 16 with the phase of the reference signal from the reference signal generation circuit 12. This phase error signal is supplied to the VCO 18. The drive signal output from VC018 is controlled by this phase error signal. This corrects the time axis fluctuation component of the reproduced video signal.

The video signal from which time-axis fluctuation components have been removed by the TBC circuit 9 is supplied to a noise canceller 19. The output of the noise canceller 19 is supplied to a terminal 21A of a switch circuit 20, and is also supplied to an A/D converter 22, where it is digitized.

The output of the A/D converter 22 is supplied to the field memory 23.

The field memory 23 is used, for example, to play back still images or play back at variable speeds on a CLV disc.

The field memory 23 stores one field worth of video signals. The output of field memory 23 is D/A
The signal is supplied to an interpolation circuit 26 via a converter 25. The interpolation circuit 26 generates one frame worth of video signals from the video signals stored in the field memory 23. The output of the interpolation circuit 26 is supplied to the terminal 21B of the switch circuit 20. Terminal 2IC of switch circuit 20
The output from is taken out from the output terminal 27.

The operation of the interpolation circuit 26 will be described in detail. As shown in FIG. 3, the field memory 23 stores video signals D1o, +, D (lot, D I
! Suppose that oz,... are stored. If the line correlation is strong, as shown in Figure 4, the lines of odd fields! . 3 and its adjacent line #1lk41, the line l@ of the even field is line l. k and l.

Average value of k+1 video signals 'A ・(D x,, +
D Nov-+) I can't get it.

Two fields of video signals of the same field are continuously read out from the field memory 23. However, if the field to be continuously read out is, for example, an odd field screen, the equalization pulse is replaced and the phase of the chroma signal is inverted so that the next field to be read out is an even field. These controls are
This is done by the controller 24.

The video signal read out from the field memory 23 is
After being returned to an analog signal by the D/A converter 25, it is supplied to the Y/C separation circuit 30 of the interpolation circuit 26 shown in FIG. A Y/C separation circuit 30 separates this video signal into a luminance signal Y and a chroma signal C.

The separated luminance signal Y is sent to the terminal 32A of the switch circuit 31.
is supplied to Along with this, this luminance signal '#+<L
The signal is supplied to the adder circuit 34 via the H delay circuit 33. The adder circuit 34 is supplied with the luminance signal Y from the Y/C circuit 30. For example, when the video of odd field line 1 OK+1 is output from the Y/C separation circuit 30, I
The H delay circuit 33 outputs the video signal of the previous line of the odd field, l1ok. For example, the adder circuit 34 selects the adjacent line l of an odd field. With k! . 11+
1 video signal is added. The output of the adder circuit 34 is 2
The signal is supplied to the circuit 35. The second circuit 35 outputs a video signal having an average value of the video signals of adjacent lines. The outputs of these two circuits 35 are supplied to the terminal 32B of the switch circuit 31.

The output from the terminal 31G of the switch circuit 31 is added to the adder circuit 3.
6. Further, the chroma signal C separated by the Y/C separation circuit 31 is supplied to the addition circuit 36.

The switch circuit 31 is controlled by a switch control signal output from a switch control circuit 37.

A vertical synchronization separation circuit 38 separates the vertical synchronization signal, and this vertical synchronization signal is supplied to the switch control circuit 37 . Further, the luminance signal from the Y/C separation circuit 31 and the luminance signal passed through the IH delay circuit 33 are supplied to the correlation detection circuit 39.

Two fields of video signals of the same field are continuously read out from the field memory 23, and one frame of video signals is generated from these two fields of video signals. If, for example, odd field video signals are stored in the field memory 23, when the odd field video signals are to be output from the interpolation circuit 26, the terminals 32A and 32C of the switch circuit 31 are connected. Therefore, in this case, the luminance signal Y and chroma signal C separated by the Y/C separation circuit 30 are combined again by the addition circuit 36 and output.

When an even field video signal is to be output from the interpolation circuit 26, the switch circuit 31 is controlled according to the output of the correlation detection circuit 39. When the correlation detection circuit 39 detects a line correlation of a predetermined value or more, the switch circuit 3
1 terminal 32B and terminal 32C are connected. When the correlation detection circuit 39 does not detect a line correlation of a predetermined value or more, the terminals 32A and 32C of the switch circuit 31 are connected.

That is, as described above, for example, the line β of an odd field is stored in the field memory 23. I+j”62+1
Assuming that video signals of 03,... are stored,
If the line correlation is strong, the line β of the odd field. 1
and β. Line 1 of even field between +1++
os is line l. k and line 10. , the average value of the video signal A・(D ji! ok+ D 12°3.1
) can be obtained from

When the line correlation is not strong, the screen may become blurred if the next field's line is formed from the average value of the adjacent lines in this way.

When the terminal 32'B and the terminal 32G of the switch circuit 31 are connected, the average value of the adjacent lines output from the two circuits 35 is supplied to the adding circuit 36. Therefore, when the line correlation is strong, an even field line is formed by the average value of adjacent lines, and this even field video signal is output from the adder circuit 36.

When the terminals 32A and 32C of the switch circuit 31 are connected, the video signal of the previous field is supplied to the adder circuit 36. Therefore, when the line correlation is weak, the video signal of the previous field is held and output from the adder circuit 36.

In this way, the interpolation circuit 26 generates a video signal for one field by reading out the video signal for one field stored in the field memory 23 twice in succession. This l-frame video signal is output from the adder circuit 36 and supplied to the terminal 21B of the switch circuit 20 in FIG.

In the above embodiment, the video signal is separated into Y/C, and the luminance signal Y of the next field is formed by interpolation.
Although video signals for frames are obtained, composite video signals may also be processed as they are. Alternatively, these processes may be performed using component video signals.

Furthermore, in the above-described embodiment, after the video signal read out from the field memory 23 is converted back into an analog signal,
Although processing is performed to obtain video signals for frames, it is also possible to perform these processings on digital signals as they are.

Furthermore, this invention is not limited to video disc players.
It can be applied to other video equipment such as VTR.

〔Effect of the invention〕

According to this invention, an image signal for one frame can be obtained from an image signal for one field stored in a field memory. Therefore, using the field memory, it is possible to reproduce an image equivalent to that when using the frame memory.

In this way, it is possible to reproduce an image equivalent to that when using a field memory using a field memory, thereby reducing costs and downsizing the device.

Furthermore, by using the field memory in this way to obtain the image signal for the (1) frame, even when a fast-moving screen is played back as a frame still, screen shaking will not occur.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of this invention, FIG. 2 is a block diagram of an example of a video disc player to which this invention is applied, and FIGS. 3 and 4 are explanations of an embodiment of this invention. FIG. Explanation of main symbols in the drawings 23: Field memory, 26: Interpolation circuit, 33: I
H delay circuit, 39: correlation detection circuit. Agent Patent Attorney Masatoshi Sugiura

Claims (1)

[Scope of Claims] An image memory that stores one field's worth of image signals; an interpolation circuit that forms the next field's image signal using the one field's worth of image signals stored in the image memory; and a correlation between each line. and a correlation detection circuit for detecting the correlation, and the interpolation circuit forms an image signal for the next field from the average value of the adjacent lines stored in the image memory when the correlation is strong, and An image processing device that obtains one frame's worth of image signals from one field's worth of image signals and the next field's image signals formed by the interpolation circuit.