JPH03216080A - Video signal processing unit - Google Patents

Abstract

PURPOSE:To expand a picture consecutively smoothly by applying interpolation processing to a video signal corresponding to an area set so as to decrease a prescribed area on a pattern sequentially so as to form the video signal corresponding to the prescribed area. CONSTITUTION:When an electronic zoom switch 31 is closed, a signal SM from a flip-flop 8 goes to a high level (electronic zoom mode) and a TELE switch 32 is closed, a luminance signal and a color difference signal are written in field memories 25, 44 while the written area is sequentially decreased for every prescribed time, e.g. for 1sec and a luminance signal and a color difference signal are read from a prescribed area at all times by interpolation processing from the field memories 25, 44 to form a luminance signal and a color difference signal for magnified picture with a prescribed magnification. Thus, after magnifying picture with mechanical zoom mechanism, the electronic zoom mechanism magnifies the picture smoothly consecutively.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention provides a video signal processing device suitable for application to a video camera.

[Prior Art] Conventionally, some video cameras have a mechanical zoom mechanism. In other words, the zoom ring of the imaging lens is
By adjusting the rotation in the ELE direction or the WIDE direction, an enlarged image of a predetermined magnification is obtained.

In addition to the mechanical zoom mechanism, an electronic zoom mechanism has also been proposed. That is, an enlarged image of a predetermined magnification is obtained by performing interpolation processing on a video signal corresponding to a predetermined area of the screen and forming an enlarged image video signal.

It has been considered to further enlarge the image using an electronic zoom mechanism after enlarging the image using a mechanical zoom mechanism.

[Problems to be Solved by the Invention] However, the magnification of conventional electronic zoom mechanisms is constant, for example, 2x, and as soon as the electronic zoom mechanism is turned on, the image suddenly increases discontinuously and the subject There were disadvantages such as losing track of the image and the roughness of the image suddenly becoming noticeable due to interpolation.

Therefore, in the present invention, it is possible to continuously and smoothly enlarge an image using an electronic zoom mechanism.

[Means for Solving the Problem] The present invention sets areas on a screen having a constant area so that they become smaller sequentially, and performs interpolation processing on the video signal corresponding to the unset area to achieve the above-mentioned constant 11. It is characterized by forming a corresponding video signal.

[Function] According to the above configuration, by sequentially decreasing the setting area from a fixed area, the magnification factor by the electronic zoom mechanism increases sequentially from 1x. Therefore, after the image is enlarged by the mechanical zoom mechanism, it is possible to roughly and continuously enlarge the image smoothly by the electronic zoom mechanism.

[Embodiment] An embodiment of the present invention will be described below with reference to FIG.

In the figure, 1 is an imaging lens, and 2 is its zoom link. The zoom ring 2 is rotated by the zoom motor 3.
It is made to rotate in the ELE direction or the WIDE direction. The zoom motor 3 is driven by a motor try 1 circuit 4, and this motor try circuit 4 is controlled by a controller 5.

Controller 5 has a zoom-in switch (TEL
E switch) 32 and zoom out switch (W
An IDE switch) 33 is connected, and a switch (X-element zoom switch) 31 for activating electronic zoom is also connected.

In mechanical zoom mode, when the TELE switch 32 is turned on, a control signal for rotating the zoom ring 2 in the TELE direction is supplied from the controller 5 to the motor drive circuit 4, while the WIDE switch 33 is turned on. At this time, the controller 5 supplies the motor drive circuit 4 with a control signal for rotating the zoom ring 2 in the WIDE direction.

A current detector 6 detects the current flowing through the zoom motor 3, and a detection signal from the current detector 6 is supplied to a pulse generator 7. In the pulse generator 7, the detection signal is compared with the reference level Vn, and when the detection signal becomes larger than the reference level Vn, a signal of high level rHJ is outputted.

The output signal of the pulse generator 7 is supplied to the set terminal S of the RS flip-flop 8. This flip-flop 8 has a signal supplied to its set terminal S at a low level rL.
It is set when the state changes from J to high level "H", and a high level rHJ signal is output to its output terminal Q.

The reset terminal R of this flip-flop 8 is reset by being supplied with a reset signal from the controller C2 and controller 5 when the power is turned on and when transitioning from the electronic zoom mode to the mechanical zoom mode F as will be described later. A low level "L" signal is output.

Signal SM output to output terminal Q of flip-flop 8
is supplied to the controller 5 as a zoom mode switching signal. In this case, when the signal SM is low level "L", the mechanical zoom mode is set;
When the mode is "H", the electronic zoom mode is activated.

Image light from a subject (not shown) is supplied to an image sensor, for example, a CCD solid-state image sensor l2, via an imaging lens 1 and an iris 11. Image taken from this image sensor 12
The l word is supplied to the process circuit l4 via the AGC amplifier 13, and the process circuit 14 outputs a luminance signal Y and a color difference signal (red difference signal R-Y, blue difference signal B-
Y) is output.

Note that the image signal from the image sensor 12 is sent to the level detector l5.
The detection signal is supplied as a control signal to the iris driver 16, and the opening of the iris 11 is controlled by the iris driver 16.

Further, the output signal of the AGC amplifier 13 is sent to the level detector 17.
The detection signal is supplied to the AGC via the amplifier 18.
The signal is supplied to the amplifier 13 as a control signal. 13a is AG
This is a potentiometer for setting the maximum gain of C amble I3.

The luminance signal Y output from the process circuit 14 is supplied to the encoder 2l via a series circuit including a comma correction circuit 19 and a gain amplifier 20, and a synchronization signal is added to the encoder 21.

The luminance signal Y output from the encoder 21 is supplied to a sync separation circuit 22, and the horizontal sync signal HD and vertical sync signal VD separated by the sync separation circuit 22 are supplied to the controller 5.

Further, the luminance signal Y output from the encoder 21 is band-limited by a low-pass filter 23, and then passed to the A/D converter 2.
4 is converted into a digital signal and stored in the field memory 25.
It is supplied as a write signal. This field memory 25 receives a write control signal W-C from the controller 5.
NT and a read control signal R-CNT are supplied to control writing and reading thereof.

Although not mentioned above, the sampling frequency in the A/D converter 24 is, for example, 4 f sc (f sc is the color subcarrier frequency), and the number of samples in one horizontal period is 9.
It becomes 10. In addition, the field memory 25 has a maximum of 262.5 lines x 7 samples, considering the effective screen, whereas one field has 262.5 lines x 910 samples.
80 samples are written (see Figure 2).

When the electronic zoom switch 31 is turned on, the signal SM from the flip-flop 8 is high level "H" (electronic zoom mode), and the TELE switch 32 is turned on, the field memory 25 stores data for a certain period of time Ta, for example, 1 sec.
In particular, the writing area is sequentially made smaller and the luminance signal is written, and at the same time, the luminance signal of a constant area is always read out from this field memory 25 by interpolation processing, and a luminance signal for an enlarged image of a predetermined magnification is formed. be done. In this case, the luminance signal to be written is divided into 20 blocks in the horizontal and vertical directions to form 20×20 blocks, and the interpolation process is performed for each block.

For example, between the first Tall after the signal SM becomes high level rHJ, a signal of 260 lines x 780 samples is written to the field memory 25, and a signal of 260 lines x 780 samples is read from the field memory 25. A signal with a magnification of 1 is formed.

Here, one block of signals to be written is 13 lines x
This results in 39 samples, and this block is output as is (as shown in FIG. 3A).

In this case, the 121st to 900th samples are written in the same horizontal direction (as shown in FIG. 4B,
The horizontal synchronizing signal HD is shown in FIG. 1), and is read out at timings corresponding to the 121st to 900th samples (shown in D of the same figure). In the vertical direction, the second
~261st line, 265th to 5th in even fields
24 lines are written (as shown in FIG. 5B, and vertical synchronization signal VD is shown in FIG. 5A), the 2nd to 261st lines are written in odd fields, and the 265th lines are written in even fields
- It is read out at the timing corresponding to the 524th line (shown in D of the same figure).

In the 28th Ta interval, the 3rd Ta period, ... the 7th Tatll J interval, and the subsequent periods, the signal of y line x x sample is written to the field memory 25, and this field memory 25 2 more
A signal of 60 lines x 780 samples is read out, and a signal with a magnification of m = 260/V = 780/x is formed. Here, one block of the signal to be written is y/20 lines Xx/20 samples, and this block is interpolated by processing such as so-called double reading and output as 13 lines x 39 samples (Fig. 3B (illustrated).

In this case, in the horizontal direction, the (121+x') to
The (120+x' +x)th sample is written (as shown in FIG. 4C) and read out at timings corresponding to the 121st to 900th samples (as shown in FIG. 4D).

Here, X is (780-x)/2.

In the vertical direction, the (2+y'
) to (1+y' +y) lines, and in even fields, (5+3y' +y) to (4+3y' +2y) lines.
As lines are written (as shown in FIG. 5C), they are read out at timings corresponding to the 2nd to 261st lines in odd fields and the 265th to 524th lines in even fields (as shown in FIG. 5D). Here, y' is (26
0-y)/2.

For example, in the second Ta Tomoma. v=240, X=72
0, m = 1.08, in the third TaIll open, y = 220, Dem
= 1.30, and in the 5th Ta period, y = 180,
x=540, m=1. 44, and the sixth Ta
In the period y = 160, X = 480, m = 1.63, and in the 7th Ta period V = 1 40, x = 420
Then, m = 1.86, and after that period, y = 1
20, x=360, and m=2.16.

Note that when the TELE switch 320 on state is released within the first to seventh Ta periods, the released Ta
The luminance signal of the magnification between the gates is repeatedly formed.

The TELE switch 3 is turned on again from the state where the brightness signal of the magnification in the 1st to 7th Ta period is repeatedly formed.
2 is turned on, the state shifts from that Ta interval to the next Ta interval for a certain period of time, and luminance signals with sequentially increased magnifications are formed in the same way as described above.

On the other hand, when the WIDE switch 33 is turned on from a state in which the brightness signals of the magnifications in the first to seventh Ta periods are repeatedly formed, the brightness signal of the magnification in the first to seventh Ta periods is In between, luminance signals with successively lower magnifications are formed.

Then, after the first Ta period has elapsed, a reset signal is supplied from the controller 5 to the reset terminal R of the flip-flop 8, and the signal SM is set to low level "L" to enter the mechanical zoom mode. As a result, the above-described write and read processing in the field memory 25 is stopped.

Note that when the electronic zoom switch 31 is turned off while the luminance signal of the magnification between the 1st and 7th TalEjJ is being repeatedly formed, the above-described writing and reading process in the field memory 25 is stopped. .

Further, when the electronic zoom switch 3l is off, the signal SM from the flip-flop 8 is high level "H" (electronic zoom mode), and the WIDE switch 33 is turned on, the controller 5 sends the reset terminal of the flip-flop 8 A reset signal is supplied to R, and the signal SM is set to low level "L" to set the mechanical zoom mode.

Further, when the electronic zoom switch 31 is off, the signal SM is at high level "H" (electronic zoom mode), and the electronic zoom switch 31 is turned on from off, the writing/reading process in the field memory 25 is The field memory 25 outputs a luminance signal with a multiplication factor of 1. When the TELE switch 32 is turned on in this state, a state is reached in which a luminance signal with a sequentially increased magnification is generated every fixed time Ta as described above.

Returning to FIG. 1, the luminance signal Y' outputted from the field memory 25 is converted into an analog signal by the D/A converter 26, and the synchronization signal SYNC supplied from the controller 5 is added by the adder 27. Later changeover switch 28
of a {is supplied to the fixed terminal of II1. The brightness signal Y output from the low-pass filter 23 is supplied to the b-side fixed terminal of the changeover switch 28.

The switching of this changeover switch on the second day is controlled by the controller 5. That is, when the electronic zoom switch 31 is on and the signal SM from the flipflop 8 is high level "H" (electronic zoom mode), a(
ljl, and otherwise connected to the b side.

Further, the color difference signal R − outputted from the process circuit l4
Y. B - Y is the encoder 21, for example NT
Corresponding to the SC system, the signal is subjected to quadrature two-phase modulation to form a carrier color erasing code C. This color signal C is band-limited by a hunt bus filter 41, then converted into a digital signal by an A/D converter 42, and supplied to a color demodulation circuit 43 for demodulation.

The color difference signal R-Y. from this color demodulation circuit 43. B-Y is
The signal is supplied to the field memory 44 as a write signal. Writing and reading operations in this felt memory 44 are controlled by the controller 5 in the same manner as in the felt memory 25 described above.

The color difference signal outputted from the field memory 44 is supplied to a color modulation circuit 45, and the color modulation circuit 45 forms a carrier color signal C'. This color signal C' is converted into an analog signal by a D/A converter 46, and then a changeover switch 47
Supply it to the fixed terminal on the a side. This changeover switch 47
The achromatic code C output from the hunt-pass filter 4 is supplied to the fixed terminal on the b side of the filter.

The switching of this changeover switch 47 is controlled by the controller 5 in the same manner as the changeover switch 28 described above.

Further, the luminance signal and color signal outputted from the changeover switches 28 and 47, respectively, are supplied to an adder 5l and added thereto, and the color video signal SV outputted from the adder 51 is supplied to an output terminal 52.

In the above configuration, the signal S from the flip-flop 8
When M is in the mechanical zoom mode at low level "L" (see Fig. 6E), when the TELE switch 32 is turned on, the zoom motor 3 is rotated under the control of the controller 5 and the zoom ring 2 is in the TELE mode. direction (as shown in Figure B). At this time, the changeover switch 28
and 47 are connected to the b side, so that the video signal S■ whose magnification is sequentially increased by mechanical zooming is outputted to the output terminal 52.

If the TELE switch 32 is left on, the detection signal of the current detector 6 reaches the reference level Vn at the time t when the zoom ring 2 rotates to the maximum position in the TELE direction and stops.
becomes larger (as shown in C in the same figure), and a high-level rHJ signal is output from the pulse generator 7 (as shown in D in the same figure).
. As a result, the flip-flop 8 is set and the signal SM becomes high-level "H" (as shown in FIG. 5E), and the mechanical zoom mode is shifted to the electronic zoom mode.

When the electronic zoom mode is activated, the rotation of the zoom motor 30 is stopped under the control of the controller 5.

When in electronic zoom mode, electronic zoom switch 3I
is in the on state and the TELE switch 32 is left on, the field memories 25 and 44 output 1x, 1.08x, ]. 18
A single luminance word and a color difference signal whose magnification is increased in order of magnification are output (as shown in F in the same figure). At this time, the changeover switches 28 and 47 are connected to a9PI, so the video signal S■ whose magnification is sequentially increased by electronic zooming is outputted to the output terminal 52.

Here, the ON state of the TELE switch 32 is 1st to 7th.
When the cancellation occurs in the Ta period, the field memories 25 and 44 repeatedly output the luminance signal and color difference signal of the magnification in the canceled Ta interval, and the output terminal 52 outputs the brightness signal and color difference signal of the magnification in the canceled Ta interval. The video signal S■ with a magnification of is repeatedly output.

When the TELE switch 32 is turned on again from this state, the state between Tall shifts to a certain period Ta, particularly to the next Ta period, and the output terminal 52 receives the magnification sequentially by the electronic zoom as described above. The enlarged video signal S■ is output.

On the other hand, when the VIDE switch 33 is turned on from a state in which the video signal S■ of the magnification in the 1st to 7th Ta periods is repeatedly not output, the video signal S■ of the magnification in the 1st to 7th Ta periods is turned on, The field memories 25 and 44 output a luminance signal and a color difference signal whose magnifications are successively decreased, and the output terminal 52 outputs a video signal S■ whose magnifications are successively decreased by the electronic zoom. Zareru.

If the WIDE switch 33 is left on, a reset signal is supplied from the controller 5 to the reset terminal R of the flip-flop 8 after the first Ta period has elapsed, the signal SM becomes low level "L", and the mechanical switch is switched from the electronic zoom mode. The target zoom mode is entered, and the writing/reading process in the field memories 25 and 44 is stopped. At this time, since the changeover switches 28 and 47 are connected to the b side, the video signal S■ at the maximum magnification by mechanical zooming is outputted to the output terminal 52.

When entering mechanical zoom mode, WIDE switch 33
If it remains on, the zoom motor 3 is rotated under the control of the controller 5 and the zoom ring 2 is set to WID.
It is rotated in the E direction.

At this time, the changeover switches 28 and 47 are connected to the b side, and the video signal SV whose magnification is successively reduced by mechanical zooming is output to the output terminal 52.

If the W I D E switch 33 is left on, the detection signal of the current detector 6 becomes larger than the reference level Vn when the zoom ring 2 rotates to the maximum position in the W I D E direction and stops, and the pulse The generator 7 outputs a high-level "H" signal. As a result, the flip-flop 8 is set, the signal SM becomes high level rHJ, and the rotation of the zoom motor 3 is stopped under the control of the controller 5. Immediately thereafter, although not mentioned above, a reset signal is supplied from the controller 5 to the reset terminal R of the flip-flop 8, and the signal SM is returned to low level "L".

Further, if the electronic zoom switch 3l is turned off while the video signal S2 of the magnification between the first to seventh talls is being repeatedly formed, the writing/reading process in the field memories 25 and 44 is stopped.

At this time, since the changeover switches 28 and 47 are connected to the b side, the video signal SV at the maximum magnification by mechanical zooming is outputted to the output terminal 52.

Further, when the electronic zoom switch 31 is off and the signal SM from the flip-flop 8 is high level "H" (electronic zoom mode), even if the TELE switch 32 is turned on, the field memories 25 and 44 cannot be read or written. processing is no longer carried out, the changeover switches 28 and 47 are connected to bm, and the video signal S■ at the maximum magnification by mechanical zooming continues to be output to the output terminal 52.

In addition, when the electronic zoom switch 31 is off and the signal SM from the flip-flop 8 is high level "H" (electronic zoom mode), when the electronic zoom switch 3l is turned on and then the TELE switch 32 is turned on, the The write and read processes are performed in the storage memories 25 and 44, and the changeover switches 28 and 47 are connected to a (Rl), and the video signal SV whose magnification is sequentially increased by electronic zoom is output to the output terminal 52. .

In addition, when the electronic zoom switch 31 is off, one word SM from the fliff "fukop 8" is high, and the WIDE switch 33 is turned on in the health rHJ (electronic zoom mode),
A reset signal is supplied from the controller 5 to the reset terminal R of the flip-flop 8, and the signal SM becomes low level.
The zoom motor 3 is rotated under the control of the controller 5, and the zoom ring 2 is rotated in the WIDE direction. As a result, the changeover switches 28 and 47 are connected to the b side, and the video signal S■ whose magnification is successively reduced by mechanical zooming is outputted to the output terminal 52.

As described above, according to this example, the magnification of electronic zoom during enlargement is: 1x; 1. 08 culture, 1. 18 days, ・ ・
Since the image size increases sequentially as shown in . . , after image enlargement using mechanical zoom, image enlargement using electronic zoom can be performed continuously and smoothly.

On the other hand, the magnification of electronic zoom during reduction gradually decreases until it reaches 1x, so after image reduction using electronic zoom, image reduction using mechanical zoom can be performed continuously and smoothly. reactor.

In the above-described embodiment, the rotational position of the zoom ring 2 is detected by detecting the current of the zoom motor 3, but other detection means may also be used. For example, this can be done using a switch or the like.

Further, the example of the magnification by electronic zoom in the above-described embodiment is only an example, and the present invention is not limited to this. Smoothness can be further improved by making the intervals between the @ rates even finer.

[Effects of the Invention] As explained above, according to the present invention, by gradually decreasing the set area from a fixed area, the magnification ratio of 18 by the electronic zoom mechanism is gradually increased from 1x. After enlarging the image using the zoom mechanism, it should be possible to continuously and smoothly enlarge the image using the electronic zoom mechanism. Therefore, it is possible to avoid inconveniences such as losing sight of the subject or sudden roughness of the image when the image is enlarged using the electronic zoom mechanism.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2 to 5 are diagrams for explaining signal processing in the field memory, and FIG. 6 is a diagram for explaining the operation of the embodiment. be.・Imaging lens・Zoom ring・Zoom motor・Controller・Current detector・Pulse generator 8...RS flip-flop l2...CCD solid-state sensor element 2 5, 2 8, 1 4 ・ 2 1 ・ 4 4 ・4 7 ● 5 2 ・Process circuit φ encoder, field memory, changeover switch, output terminal

Claims (1)

[Claims] (1) The feature is that areas are set on a screen having a certain area so that they become smaller one after another, and the video signal corresponding to the set area is subjected to interpolation processing to form a video signal corresponding to the certain area. A video signal processing device.