JPH08294036A - Video camera with automatic zooming - Google Patents

Abstract

PURPOSE: To provide the video camera with automatic zooming in which pickup of a portrait is facilitated. CONSTITUTION: The camera is provided with a zoom lens 1, a projector 14, a correlation device 16, and an automatic zoom controller 18, the projector 14 emits a light intermittently to an object, and the correlation device 16 inputs an image signal stored in a memory device 6 and an image signal from an image pickup section 2 to an adder 7 to provide luminescent spot information to an automatic zoom controller 18 when both eyes of the projector 14 irradiates the image. The automatic zoom controller 18 controls the zoom driver 12 so that the interval of both the eyes of the image detected from the luminescent spot information of both the eyes to be received is a prescribed interval.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera with automatic zoom for recording moving images on a recording medium.

[0002]

2. Description of the Related Art In recent years, along with the widespread use of video cameras, automation of various adjusting mechanisms of video cameras has been advanced. For example, there is a video camera equipped with a mechanism for automating white balance, automating exposure adjustment, and autofocusing. However, only the adjustment of the zoom has not been attempted because the operator's will is involved.

[0003]

The above-described zoom adjustment is a troublesome operation for the photographer when shooting with a video camera whose angle of turn is automated.

Therefore, there is a demand for further improvement in usability by providing an automatic zooming adjustment function when photographing a person, and in particular, an automatic zooming function is a problem for a video camera that always captures an image of a person. .

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a video camera with an automatic zoom for easily photographing a person.

[0006]

Therefore, the video camera with automatic zoom according to the present invention includes: (1) video camera means for recording a moving image on a recording medium, and light projection for intermittently irradiating a subject with light. Means and a control means for controlling the both means, wherein the video camera means comprises a zoom lens having a variable lens focal length, and a driving method for changing the focal length of the zoom lens. And a signal processing unit that processes an image signal from the imaging unit and converts the image signal into a video signal and outputs the video signal. Image memory means for storing the image signal from the image pickup section, and correlation means for inputting the stored image signal and the image signal from the image pickup section into the image memory means and correlating them to output specific image information separately. The automatic zoom control means for calculating the binocular distance of the subject person image from the output information of the correlating means and controlling the zoom drive device so that the distance becomes a predetermined value. Is to achieve the purpose of.

(2) In the above structure, the correlating means inputs the image signal when the light projecting means is illuminating and the image signal when the light is not illuminating, and the light projecting means projects the binocular image of the subject person image when the light is illuminated. It is intended to achieve the above-mentioned object by a configuration characterized by outputting bright spot information.

(3) In the above structure, the wavelength of the light emitted from the light projecting means is a wavelength within the spectral sensitivity of the image pickup section, or the wavelength of the image signal of the image pickup section. It is an object of the present invention to achieve the above object by a structure characterized by being in a red signal region or a structure characterized by near infrared rays.

[0009]

With the above arrangement, the image pickup size of a person can be determined by utilizing the so-called "red eye phenomenon" when a person is imaged.

That is, according to the above-mentioned structure, the light projecting means is intermittently illuminated and irradiated, and at least one image memory means is used to input the image signals at the time of irradiation and non-irradiation to the correlating means, and the correlating means extracts them. It is possible to calculate the distance between both eyes of the human image based on the "red eye" information of the captured image and control the zoom so that the distance between both eyes of the human image becomes constant.

[0011]

1 is a block diagram showing the configuration of an embodiment of the present invention.

Light from a subject (not shown) is imaged on the image pickup surface of the image pickup section 2 by the zoom lens 1. The image pickup unit 2 photoelectrically converts the light from the subject into an electric signal, performs necessary processing, and then outputs it as an R, G, B video signal. The B and G signals are respectively delayed circuits 5-1 and 5-2.
Is sent to the process circuit 3 via. The R signal is sent to the process circuit 3 via the delay circuit 5-3 and the adder 8.

In the process circuit 3, after performing necessary processing, for example, white balance and γ correction, luminance Y, color difference RY,
The signals are output as BY signals and sent to the encoder circuit 4. The encoder circuit 4 converts the signal from the process circuit 3 into a video signal and outputs it.

On the other hand, the R signal output from the image pickup section 2 is input to one input section of the memory device 6 and the adder 7 in the correlator 16. The output of the memory device 6 is input to the + input section of the adder 7. The output of the adder 7 is input to the other input terminal of the adder 8 and also the AGC of the automatic zoom controller 18
Input to the circuit 9.

The output of the AGC circuit 9 is input to the binarization circuit 10, converted into a binary signal of "1" and "0" and sent to the zoom control device 11.

The zoom control device 11 drives the zoom drive device 12 by performing calculation based on the signal from the binarization circuit 10. Reference numeral 17 indicates an absolute value circuit.

A light projecting device 14 is also provided and is under the light projecting control by the light projecting control device 13.

Further, the SG 15 for generating the whole time timing signal, the drive timing signal for the image pickup device in the image pickup device 2, the various timing signals for generating the video signal, etc. is supplied to the blocks necessary for each SG 15. Is being sent.

Although the signal path from the SG 15 is shown only in the portion necessary for the explanation of this embodiment in FIG. 1, it goes without saying that it is actually supplied to the block necessary for processing.

The wavelength of the light emitted from the light projecting device 14 is red (for example, red in the spectral sensitivity region of the R signal of the image pickup section in FIG. 1) or invisible to humans but sensitive to the image pickup section 2. Near-infrared rays having In particular, near-infrared rays are more preferable because they are invisible to human eyes and do not affect surrounding scenes, and there are no effects such as "blinking" and "pupil closure" of human eyes.

Next, the operation of the embodiment will be described.

The light projecting device 14 is controlled by the light projecting control device 13 so as to intermittently repeat light emitting and extinguishing for each frame. This control situation is shown in the timing chart of FIG.

FIG. 2C shows the timing of turning on and off the light projecting device. That is, lighting and extinguishing are repeated for each frame. Incidentally, lighting, switching of off, as shown in the timing chart of (2) in FIG. 2, it is performed after the so-called transfer gate pulse phi _t.

As is well known, the transfer gate pulse φ _t is a pulse for transferring the charge accumulated in the photoelectric conversion element (for example, photodiode) in the solid-state image pickup element to the readout CCD transfer line. , The signal accumulated from the previous φ _t to the current φ _t is
_{Read out} before _t . Therefore, the image pickup signal during lighting of the light projecting device in the period of a is read out as a video signal in the frame period of n.

When light is emitted to an object (not shown) at such a timing of the light projecting device, the light amount increases only during the period during which the light is emitted as compared with the period during which no light is emitted.

Here, as is well known, when a person is photographed as a subject, when strong light hits the person's face, it is reflected by the retina of the human eye to cause a red-eye phenomenon. The red-eye phenomenon occurs because the long wavelength component of light is selectively reflected by the retina.

Therefore, when light (especially red or infrared rays) is emitted at the above timing, the signal of the human eye portion is selectively emphasized. The state is schematically shown in (4) of FIG.

In FIG. 2, the video camera is schematically illustrated as being installed horizontally on a subject (the height of the human eye of the subject). Although there are two human eyes, the timing of (4) in FIG. 2 is written in the “V” cycle, and thus has one bright point.

A signal such as this is fetched into the memory device 6 (for example, a frame memory in this embodiment), the time for one frame is delayed, and the signal after one frame is subtracted by the adder 7 to obtain a frame. Correlate. The state of the frame correlation output (output of the adder 7) is schematically shown in FIG.
Shown in

Incidentally, FIG. 2 (5) schematically shows the output state of the memory device 6, and it can be seen that the signal is delayed by one frame as compared with the R signal. It can be seen that, in the R signal, the bright spot A of the eye in the nth frame period is extracted in the positive direction in the n + 1th frame period at the outputs of the correlator 16 and the adder 7. The signal components other than the eyes in the n + 1 frame period are slightly raised because
This is because the area above the eyes also reflects some light.

The output signal from the correlator 16 is input to the middle point of the switch 19, and the switch 19 switches between "correlation output" and "reference 0 level" for output (FIG. 2). (7)). This signal is added to the R signal by the adder 8 to cancel the influence of the light projecting device 14 in the video signal.

The delay circuit 5-3 corrects the time delay of the path to the output of the switch 19, and the delay circuit 5-3
-1, 5-2 are for correcting the time delay until the output of the adder 8 of the R signal system. Therefore, if the time delay does not occur, 5-1 to 5-3 are unnecessary.

By controlling the timing as described above, the influence of the light projecting device (for example, the red-eye phenomenon) on the video signal is eliminated, and a normal good image is obtained.

Next, the zoom control will be described.

The output of the correlator 16 (adder 7) is sent to the automatic zoom controller 18. Automatic zoom controller 18
Then, in the absolute value circuit 17, the polarity of the output signal of the correlator 16 is made the same in all frames ((8) in FIG. 2),
The AGC circuit 9 controls the level so that the peak level becomes constant (so that the peak level at the starting point of the eye becomes constant),
The binarization circuit 10 converts the signals into "1" and "0" signals ((9) in FIG. 2). In this way, the position of the human eye is extracted.

The position information of the human eye extracted as described above is calculated by the zoom control device 11 as the distance (distance) between the eyes of the human image, and the zoom drive device 12 is adjusted so that the distance becomes a certain value. To control. A certain value determines the size of the face of the human image at that time, that is, the distance between the eyes, if the imaging size is determined to be a bust shot in advance. Therefore, if the zoom is controlled so that the distance between the eyes of the image is controlled, the desired image pickup size can be automatically determined.

The zoom control device 11 is an arithmetic unit,
For example, it is composed of a small electronic computer (microprocessor) and simple hardware.

To obtain two-dimensional position information from the binarization circuit 10, in the "V" direction, the counter is incremented every "VD" to "HD", and "1" is output from the binarization circuit. It suffices to acquire the value of the counter when the information of is entered.

For the information in the "H" direction, the counter is started from "HD", the counter is incremented by a certain reference clock, and the counter when the information of "1" from the binarization circuit is entered. Just get it. As the reference clock, it is sufficient to use, for example, the clock for the image pickup device of the image pickup unit.

The eye distance of the image is calculated from the two-dimensional position information of the "red eye" obtained as described above. (Since the calculation method is well known in various image processing, here, The description is omitted), and the zoom is controlled as described above.

The absolute value circuit 17, AG in this embodiment is
Since the C circuit 9 and the binarization circuit 10 are provided for the purpose of extracting the position information (position information in the two-dimensional image) of the "red eye" information extracted by the correlation, the configuration is limited to this. Not a thing.

Since FIG. 2 was a primary explanation of the V period, FIG. 3 shows a two-dimensional schematic diagram.

FIG. 3 is a schematic diagram of an image in which the positions of the bright points of the human eye, which are extracted by the automatic zoom control device, are restored to the captured image. The dotted line in the figure is a person image as a video signal, but the image signal of the person is not transmitted within the automatic zoom control device, but only the information of the human eye is transmitted.

In this embodiment, an example of extracting "red eye" information by frame correlation is described, but the present invention is not limited to this method. For example, the information may be extracted by field correlation.

In the present embodiment, the information extraction point in the circuit for obtaining the correlation is extracted from the R signal output from the image pickup unit, but this is not the only option. For example, in the middle of the process circuit. (For example, after white balance and γ processing)
Information may be retrieved from. Further, not only the R signal but also the luminance signal and the color difference signal may be taken out.

[0046]

As described above, according to the present invention,
It is possible to automatically determine the image size by intermittently illuminating and correlating to extract the information on the eye distance of the human image, and controlling the zoom so that the distance becomes constant. Become. Therefore, for example, the effect of the auto-zoom shooting is great when used in a video camera for a TV conference system, a video camera for taking a certification photograph, or the like.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an example.

FIG. 2 is a timing chart showing a control situation of one embodiment.

FIG. 3 is a schematic explanatory diagram of zoom control according to an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 zoom lens 2 imaging part 3 process circuit 4 encoder circuit 5-1, 5-2, 5-3 delay circuit 6 memory device 7,8 adder 9 AGC circuit 10 binarization circuit 11 zoom control device 12 zoom drive device 13 Projection control device 14 Projection device 16 Correlator 18 Automatic zoom control device 19 Switch

Claims (5)

[Claims] 1. A video camera means for recording a moving image on a recording medium, and a light projecting means for intermittently irradiating a subject with light.
A video camera with automatic zoom, comprising: a control unit for controlling the both units, wherein the video camera unit has a zoom lens with a variable lens focal length, and a zoom drive for driving the focal length of the zoom lens. An image pickup unit for converting an optical image on an image forming surface into an electric signal; and a signal processing unit for processing an image signal from the image pickup unit and converting and outputting it into a video signal. Image memory means for storing the image signal of, and a correlating means for inputting the stored image signal and the image signal from the image pickup section to the image memory means and correlating them to output specific image information separately, The automatic zoom control means for calculating the binocular distance between the human images of the subject from the output information of the means and controlling the zoom drive device so that the distance becomes a predetermined value. Okamera. 2. The correlating means inputs the image signal when the light projecting means is illuminated and the image signal when the light is not illuminated, and the light projecting means outputs the bright spot information of both eyes of the subject person image at the time of illumination. The video camera with automatic zoom according to claim 1, wherein 3. The video camera with automatic zoom according to claim 1, wherein the wavelength of the light emitted from the light projecting means is within the spectral sensitivity of the image pickup section. 4. The video camera with automatic zoom according to claim 1, wherein the wavelength of the light emitted from the light projecting means is within the red signal region of the image signal of the image pickup section. 5. The video camera with automatic zoom according to claim 1, wherein the wavelength of light emitted from the light projecting means is near infrared light.