JPH02235488A - Reproducing device for video signal - Google Patents

Abstract

PURPOSE:To obtain a reproduced picture with natural scene even with a fast shutter speed at pickup by detecting field correlation of a reproduced video signal and adding a component of a blur or fog to a component without the field correlation. CONSTITUTION:Even when a switch 32 is closed or opened, in the case of a small non-field correlation, that is, when the movement of a reagent is small, since the relation of k=1 or k 1 exists by a signal Sm, a luminance signal Sy as an output signal Sa is outputted nearly as it is at a terminal 9. That is, a reproduced pattern similar to that by a conventional VTR is obtained. On the other hand, with the switch 32 opened and in the case of a large non- field correlation, that is, when the movement of the reagent is large, since the value (k) is small by the signal Sm, the luminance signal Sa extracted at the terminal 9 has a smaller ratio of a substantial luminance signal Sy and ratio of a defocus luminance signal Sd is increased thereby adding a blur or fog to the picture in the reproduced pattern.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a video signal reproducing device.

[Summary of the invention]

This invention enables a video signal playback device to obtain a natural playback screen even if the video signal is shot and recorded with a high-speed shutter by adding a non-blurring component to the played video signal. This is what I did.

[Conventional technology]

In the NTSC system, the field frequency is approximately 60
Hz, the exposure time (
Shutter speed) was 1 no 60 seconds.

However, in video cameras that use CCD or MOS type image sensors, even if the incident light of the subject image is continuously supplied to the image sensor, the signal charge generated by the incident light is swept away. , the actual exposure time can be made shorter than 1760 seconds, and depending on the image sensor, the exposure time can be reduced by 1/2.
A high-speed electronic shutter of about 10' seconds can also be realized.

And if you can use such a high-speed electronic shutter,
Even if the subject moves at high speed, images can be played back without blur or blur when playing back in slow motion or in still mode.

Furthermore, when photographing in an extremely bright place, such as a summer beach, it can also be used as a means to limit the amount of incident light in place of an ND filter.

Literature: Television Society Technical Report, Volume 12, No. 12, No. 3
Magazines with pages 1 to 36 [TV Technology J, November 1988 issue, pages 49 to 54, etc.]

[Means to solve the problem]

Therefore, in the present invention, the field correlation of the reproduced video signal is detected, and based on this detection output, a non-blurred component is added to the portion where there is no field correlation. It was made by sea urchin.

[Problem to be solved by the invention]

However, when shooting with such a high-speed electronic shutter, the aperture effect on the video signal decreases, the frequency characteristics of the video signal improves, and signal components with higher frequencies than necessary are obtained. Since this unnecessary Takagi component is aliased within the band of the original video signal, the playback screen becomes jerky and unnatural during normal playback.

Therefore, the high-speed electronic shutter cannot be used satisfactorily as a means for limiting the amount of incident light.

This invention attempts to solve these problems. This results in a video signal with a natural playback screen.

〔Example〕

In Fig. 1, (1) indicates a magnetic tape, and on this tape (1), an FM signal Sf modulated by a luminance signal Sy is sequentially transmitted such that one field corresponds to one diagonal magnetic track. recorded.

Further, in this example, a signal Ss indicating the shutter speed (exposure time) of the video camera at the time of recording is inserted into the vertical planking section of the luminance signal Sy recorded on the tape (1).

Then, this tape (1) is connected to the rotating magnetic head (2^》,
(2B) is run diagonally at a constant speed over an angular range of just over 180 degrees with respect to the rotating circumferential surface of the head (2 people). (2B) are rotated in field frequency with an angular spacing of 180° from each other. Thus, the head (2 people). (2B) From tape (1
) is continuously reproduced.

Then, this reproduced signal Sf is transmitted to the head (2A),
(2B) From playback amplifier [3] and limiter (4
) is supplied to the FM demodulation circuit (5) and the luminance signal s
y is demodulated, and this signal sy is sent to a delay circuit (6
) and the addition circuit (
8).

Further, the signal Sy from the demodulation circuit (5) is supplied to the addition circuit (8) through the defocus filter <<11>> and the variable attenuator circuit <<12>>.

In this case, the deforce filter (l1) has, for example, an impulse response as shown in FIG.
Is there a bright spot at the intersection (indicated by Q mark)? When the signal is displayed, within a circle of a predetermined radius centered on this bright spot,
It outputs a brightness signal Sd that displays bright spots (indicated by ● marks) at a line pitch. And the delay circuit (
6) is for compensating for the delay time in this filter (l1).

Furthermore, if the signal passing rate of the attenuator circuit (7) is the value k, then 0≦k≦1, and the signal passing rate of the attenuator circuit (12) is the value (1 − k).

The addition output Sa of the addition circuit (8) is then added to the tape (1
) is taken out to terminal (9) as a playback output.

Furthermore, the signal sy from the demodulation circuit (5) is transmitted to the delay circuit.
(21) is supplied to the luminance signal Sv delayed by one field period, and this signal Sv and the original signal Sy
is supplied to the subtraction circuit (22), and a signal SITI1 indicating non-field correlation, that is, a signal SL11 indicating the movement of the subject is extracted. And this signal Sm is
After the signal is converted into a predetermined signal form in the control circuit (23), it is sent to the attenuator circuit (7). <12) as its control signal, and when the non-field correlation indicated by the signal Sm is large, the value k is made small.

Further, the signal sy is supplied to a detection circuit (31), from which a signal Ss indicating the shutter speed at the time of recording is taken out, and this signal SS is supplied to the control circuit (23) to determine the shutter speed at the time of recording. The signal Sm is controlled so that the faster the value k is, the smaller the value k becomes.

Furthermore, the control circuit (23) includes a manual switch (32).
is connected and turned on, the signal Sffl
k=1 regardless of the

In such a configuration, when the switch (32) is on, and even when it is off, the signal S
Since k=1 to kζ1 depending on m, the luminance signal Sy is taken out almost as is at the terminal (9) as the output signal Sa. In other words, it is possible to obtain a playback screen similar to that of a general VTR.

On the other hand, when the switch (32) is off and the non-field correlation is large, that is, when the movement of the subject is large, the value k becomes small due to the signal Sm, so the luminance signal Sa taken out to the terminal (9) In this case, the proportion of the original luminance signal sy becomes smaller, and the proportion of the defocused luminance signal Sd increases, so that on the reproduced screen, the image appears to be unshaken and blurred.

In this way, according to the present invention, even if the shutter speed at the time of shooting is high, during playback, the image is not blurred and blur is added, just like when the shutter speed is normal, so that a natural-looking playback screen can be obtained. be able to. For example, even if a high-speed electronic shutter is used to reduce the light in a place with a large amount of light, a natural reproduction screen can be obtained.

Further, since the amount of blur without blurring is increased or decreased by the signal Ss in accordance with the shutter speed at the time of photographing, an appropriate reproduction screen can always be obtained.

When you want to see the movement in detail through slow playback or still playback, you can turn on the switch (32) to get an image without blur or blur.

In the example shown in FIG. 3, the circuit is also used as a noise reduction circuit.

That is, the signal sy from the demodulation circuit (5) is sent to the subtraction circuit (41). (43) and the subtraction circuit (4l
The output of the signal Sg is supplied to the delay circuit (4.2)' and is delayed by one field period to become the signal Sv,
This signal Sv is supplied to a subtraction circuit (43), and from the subtraction circuit (43) a signal Sn indicating a non-field correlation between the signals sy and Sv, that is, a signal Sn indicating a noise component and the movement of the subject is taken out. This signal Sn is supplied to the subtraction circuit (41) through the variable attenuator circuit (44).

Also, from the control circuit (23) to the attenuator circuit (44)
The control signal Sm is supplied to the attenuator circuit (44), and the faster the shutter speed is, the higher the signal passing rate k of the attenuator circuit (44) is (0≦'k<l). Note that when the switch (32) is turned on, the passage rate k is set to a constant value suitable for noise reduction regardless of the signal Ss.

Therefore, in this case, as shown in Fig. 4, the time-frequency characteristic becomes a low-pass characteristic, so the aliasing component in the luminance signal sy is suppressed and extracted as the signal Sg, resulting in a more natural movement. It can be used as a playback screen.

In addition, in the above, the defocus filter (11) can be configured as a two-dimensional moving average filter, or simply reduce the amount of correction of an averture correction circuit (not shown) or reverse the correction signal. It can also be substituted by adding the phases. Furthermore, a delay circuit (21). (4
2) can be configured using field memory or the like.

Furthermore, an electronic still camera may be used instead of a VTR. Further, color signals can also be processed in the same way.

〔Effect of the invention〕

According to this invention, even if the shutter speed during shooting is fast,
At the time of playback, the image is not blurred and blur is added like when the shutter speed is normal, so a natural-looking playback screen can be obtained. For example, even if a high-speed electronic shutter is used to reduce the light in a place with a large amount of light, a natural reproduction screen can be obtained.

Further, since the amount of blur without blurring is increased or decreased by the signal Ss in accordance with the shutter speed at the time of photographing, an appropriate reproduction screen can always be obtained.

Then, by slow playback or still playback, you can see the movement in detail.
When you want to see it, you can turn on the switch (32) to get an image without blur or blur.

[Brief explanation of drawings]

Figures 1 and 3. Systematic diagram of an example of Hoko's invention, Fig. 2,
FIG. 4 is a diagram for explaining this. (11) is a defocus filter, (7). (12>
．． (44) is a variable absorber circuit, (21). (
42) is a delay circuit. Agent Hidemori Matsukuma

Claims (1)

[Claims] In a playback device that plays back a video signal from a recording medium on which a video signal shot at a shutter speed faster than the field period is recorded, a non-field correlation component is detected from the played back video signal. a detection circuit; and a forming circuit for forming a steady and blurred signal component from the reproduced video signal, and according to a detection output of the detection circuit, the steady and blurred signal component formed by the forming circuit. , a video signal reproducing device which adds the video signal to the reproduced video signal.