JPH1175103A - Television camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always magnify and monitor a moving subject at the center part of a video monitor screen by detecting the changed variables of both luminance level and color of each of areas which are divided from a generated screen having a necessary size by a screen dividing means. SOLUTION: A microcomputer 9 detects both luminance level data and color data on the digital video signals which are processed by a digital signal processing circuit 6 in every field. The necessary decision is performed from those data detection results and the changed variables of both luminance signal level and color signals of a subject, and a control signal obtained from this decision result is outputted to a drive circuit 10. The microcomputer 9 controls the timing when an image pickup device 2 is driven by the circuit 10. The read starting and ending positions of the screen to be magnified are moved by designation of the microcomputer 9. Thus, an area to be magnified can be moved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus in which the subject being imaged is always positioned at the center of the video monitor screen even when the still object being imaged starts moving or when the moving object is imaged. The present invention relates to a television camera having a function of automatically controlling electronically so that it can be monitored, and particularly useful for capturing an image of a subject moving in a limited place indoors.

[0002]

2. Description of the Related Art A conventional television camera is used when a stationary subject being imaged starts moving, or
When capturing an image of a moving subject, to capture the moving subject or to continue monitoring the moving subject, the subject comes to the center of the video monitor screen using the following means. Or surveillance had to be within the video monitor screen. (1) The television camera is mounted on the camera platform, the camera platform on which the television camera is mounted is controlled, and movement starts.
Alternatively, the imaging direction of the television camera is always adjusted to the moving subject, and monitoring is performed so that the subject comes to the center of the video monitor screen. (2) An image of a subject is taken by a television camera using a wide-angle lens, and a wide range is monitored so that the subject remains on the video monitor screen even when the subject moves. (3) A continuous wide area is imaged by a plurality of television cameras, and even if the object moves, the wide area is set so that the object is present on the video monitor screen imaged by any of the television cameras. Monitor.

[0003]

SUMMARY OF THE INVENTION A television camera according to the prior art captures an image of a moving or moving object and starts moving.
When monitoring a moving subject is continued, there are the following problems. (1) When the camera platform on which the television camera is mounted is controlled in accordance with the movement of the object to be imaged, the camera platform must be controlled in accordance with the movement of the object or each time the object moves. In addition to the control of the television camera, there is a problem that it is necessary to control the camera platform and adjust the imaging direction of the television camera. (2) Since the subject is imaged by a television camera using a wide-angle lens, there is a problem that the size of the subject on the video monitor screen is small, the details of the subject are not clear, and it is difficult to monitor. (3) When a plurality of television cameras are used to capture a wide range, a plurality of television cameras and a changeover switch or a plurality of video monitors are required, which increases the cost and uses a changeover switch. There is a problem that the changeover switch must be switched in accordance with the movement of the subject. The present invention solves the above-described problems, and has begun to move within a predetermined range, or when monitoring a moving subject, electronically automatically follows the moving subject, using an electronic zoom function, It is an object of the present invention to provide a television camera capable of always enlarging and monitoring a moving subject at a central portion of a video monitor screen.

[0004]

In order to achieve the above object, a television camera according to the present invention comprises an imaging lens on which light from a subject enters, and a video signal obtained by photoelectrically converting light incident from the imaging lens. In a television camera having an image pickup device for outputting, a driving circuit for driving the image pickup device, and a digital processing circuit for digitally processing a video signal from the image pickup device, a required image is included in an image screen picked up by the image pickup device. A screen dividing means for generating an area obtained by dividing a screen having a size, and a change amount of a luminance level and a change amount of a color of each area of the area obtained by dividing the screen having a required size generated by the screen dividing means are detected. Detecting means, and the amount of change in the luminance level and the amount of change in the color of each of the areas obtained by dividing the screen detected by the detecting means. A comparison means for comparing, a vertical expansion means for controlling a drive circuit based on a comparison result output from the comparison means, and controlling a charge transfer timing of an image pickup element so as to expand a vertical direction of a required image portion; Horizontal enlargement means for extending the horizontal direction of the required image portion by interpolation in accordance with enlargement of the vertical direction of the required image portion by the enlargement means.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a television camera according to the present invention will be described with reference to FIGS. FIG.
FIG. 1 is a block diagram of a television camera according to the present invention. In the block diagram of the television camera of the present invention shown in FIG. 1, 1 is an imaging lens on which light from a subject is incident, 2 is an imaging device that photoelectrically converts light incident on the imaging lens 1 and outputs a video signal, Reference numeral 3 denotes a correlated double sampling (CDS) circuit for removing noise of a video signal output from the image sensor 2, and 4 denotes an automatic gain control for adjusting a video signal whose signal level fluctuates to a required level. (AGC) circuit, 5 an A / D (analog-digital) conversion circuit, 6 a digital signal processing (Digital Si
gnal Processor (DSP) circuit; 7, a D / A (digital-analog) conversion circuit; 8, an amplifier for amplifying and outputting a video signal to a predetermined level; 9, control and control of a video signal processed by a digital signal processing circuit 6; A microcomputer 10 for making a determination, a driving circuit for controlling the driving of the image sensor 2 under the control of the microcomputer 9, and a digital video signal processed by the digital signal processing circuit 6 for the microcomputer 9; 1 shows an enlargement processing circuit for performing electronic zooming under control of the electronic zoom and enlargement in the vertical and horizontal directions.

In the television camera according to the present invention, light from a subject passes through an image pickup lens 1 and enters an image pickup device 2, where the light is photoelectrically converted by the image pickup device 2 into a video signal. It is output to the double sampling circuit 3. The correlated double sampling circuit 3 removes noise mixed at the time of photoelectric conversion of the video signal input from the image pickup device 2, performs sample hold, and outputs the result to the automatic gain control circuit 4. The automatic gain control circuit 4 controls the gain so that the video signal input from the correlated double sampling circuit 3 has a required signal level even if there is a level fluctuation, and converts the video signal of the required signal level into an A / D signal. Output to the conversion circuit 5. The A / D conversion circuit 5 converts a video signal of a required signal level input from the automatic gain control circuit 4 into a digital signal in order to adapt to the subsequent digital processing, and converts the digital video signal into a digital signal processing circuit 6
Output to

The digital signal processing circuit 6 converts the digital video signal input from the A / D conversion circuit 5 into a signal for controlling image quality such as luminance signal processing, color signal processing, gamma correction and contour compensation, and adjusting white balance. The processing is performed by digital processing, and the digital video signal subjected to the signal processing is output to the D / A converter 7. The D / A conversion circuit 7 converts the digital video signal subjected to the required signal processing input from the digital signal processing circuit 6 into an analog signal, and outputs the analog video signal to the amplifier 8. Amplifier 8
The analog video signal input from the D / A converter 7 is amplified to a predetermined signal level, and output to another device, for example, a video monitor, a magnetic recording / reproducing device, etc., according to the purpose.

The operation of the above-described television camera is the same as that of a normal television camera, and the digital signal processing circuit 6 performs various kinds of signal processing.
In the television camera of the present invention, the microcomputer 9 detects luminance level data and color data for each field of the digital video signal which has been subjected to the signal processing by the digital signal processing circuit 6, and detects the luminance signal of the subject from the detection result. A required determination is made based on the level change amount and the color signal change amount, and a control signal based on the determination is output to the drive circuit 10. The drive circuit 10 outputs, to the image sensor 2, a drive signal in which the timing of charge transfer for photoelectric conversion in the image sensor 2 is controlled, and outputs a charge to the image sensor 2 based on a control signal input from the microcomputer 9. The transfer timing is controlled, and only a signal of a video portion that is enlarged by electronic zooming is output to the image sensor 2 with a drive signal that is expanded in the vertical direction and transferred as a video signal.

The video signal enlargement processing circuit 11 includes a driving circuit 1
From the digital signal processing circuit 6, a video signal in which only the video signal to be enlarged in the drive signal output from 0 is expanded in the vertical direction is input from the digital signal processing circuit 6, and the video signal in which the horizontal direction is interpolated and expanded using a memory is converted into a digital signal The signal is output to the signal processing circuit 6. When a required part of the screen is enlarged by the operation of electronic zooming, the unnecessary part of the video signal generated by enlarging the required part is quickly swept out during the vertical retrace period, and only the video signal of the part to be enlarged is a video signal. The microcomputer 9 controls the timing at which the drive circuit 10 drives the image sensor 2 so that the transfer is performed as follows. When only the video signal of the portion to be enlarged is transferred, a thinned video signal is obtained. The thinned video signal is subjected to linear interpolation and stored in a memory included in the video signal expansion circuit 11. The data stored in the memory is read out at the timing of the control circuit provided in the video signal enlargement circuit 11 according to the read start and end positions of the portion to be enlarged designated by the microcomputer 9 and vertical interpolation and horizontal enlargement processing are performed. Also, by moving the read start and end positions of the screen to be enlarged by the designation of the microcomputer 9, the area to be enlarged can be moved. (Since the technology of electronic zooming is a disclosed technology, a detailed description is omitted.)

Further, a screen division pattern to be set in the television camera according to the present invention shown in FIG. 2, a screen display explanatory view of a subject imaged by the television camera according to the present invention shown in FIG. 3, and a television according to the present invention shown in FIG. A description will be given using a flowchart for displaying or enlarging a subject to be imaged by the John camera at the center of the screen. The television camera of the present invention uses a wide-angle lens as the imaging lens 1 to capture an image so as to sufficiently include a range in which the subject moves, and the digital signal processing circuit 6
In the imaging screen, the central portion as shown in FIG.
The area surrounding the area 6 is divided into an area 5 and the remaining peripheral area is divided into four areas to provide an area 1, area 2, area 3, and area 4 screen division patterns. As shown in FIG. Are set so that the subject enters the area 6.

The digital signal processing circuit 6 and the microcomputer 9 detect the amount of change in the luminance signal level and the amount of change in the chrominance signal in each of the divided areas 1 to 6 of the image pickup screen (see FIG. 1). 4, 401). As a result of detecting the amount of change in the luminance signal level and the amount of change in the chrominance signal in each region, a change of a predetermined value or more is found in regions 1, 2, 3, and 4 of the peripheral four-screen divided region. If there is (4
For example, as shown by a dotted line in FIG. 3, when the subject moves to the area 2, it is determined that the subject has moved in the direction of the area where the change is equal to or more than the predetermined value, and the changed area is centered. Move the screen gradually to make it larger. (See 403) On the other hand, the area 6 in the center part of the screen and the area 5 in the surrounding part
When there is no change in the area 1 to the area 4 in the peripheral portion, the subject is not moving, and
Judge that the size is appropriate, and keep the magnification. (41
Further, when there is a change only in the area 6 in the center part of the screen (see 409), it is determined that the size of the subject is small,
The subject is enlarged until it reaches a size between the central area 6 and the surrounding area 5. (Refer to 411) As described above, the enlargement of the screen is continued so as to reach a size between the area 5 and the area 6. (404, 40
5, 406, 412, 413)

Further, divided areas 1 to 6 of the imaging screen
When the change amount of the luminance level and the change amount of the color of each area are smaller than the predetermined values (see 401), it is determined that the subject has not moved, the current state is held, and the current state is kept for a predetermined time or more. If none of the areas change (407
Judgment is made that the subject is completely stopped, and the magnification is gradually returned to 1 so that the entire screen can be monitored (at this time, if it is not necessary to monitor the entire screen, Maintain this state). (Refer to 408) In the above-described enlargement of the screen, the enlargement of the screen is stopped when a predetermined limit value is reached.

Further, as a result of detecting the amount of change in the luminance level and the amount of change in the color of each area, the area where the change is equal to or more than a predetermined value is two areas adjacent to the peripheral area divided into four screens. Makes the area where two regions touch each other the center of the enlargement of the screen. Further, as a result of detecting the amount of change in the luminance level and the amount of change in the color of each area, the
In the case of a region that is not adjacent to the four-screen divided region in the peripheral portion, the region with the larger change amount is set as the center of enlargement. As described above, as a result of detecting the amount of change in the luminance level and the amount of change in the color of each area, the enlargement magnification and the enlargement center position are controlled such that the area having the change always comes within the surrounding area 5. .

For example, as shown in FIG. 3, when the subject imaged in the area 6 at the center of the screen starts moving and moves from the center of the screen to the upper right, the area surrounding the area 6 at the center is Since the change amount of the luminance signal level and the change amount of the chrominance signal detected in the area 5 are detected in the upper right area 2, the change amount of the luminance signal level and the change amount of the chrominance signal are detected. It can be determined that it has moved to the upper right. In this case, since it is determined that the subject has moved to the upper right, the subject moves while gradually enlarging the screen centering on the peripheral area 2 (so that the area 6 comes to the position of the area 2).
When the size of the subject becomes larger than the surrounding area 5, the enlargement of the screen is stopped.

[0015]

According to the present invention, when monitoring a subject that has begun or is moving within a predetermined range, the moving subject is automatically and automatically followed by using an electronic zoom function. Thus, it is possible to provide a television camera capable of always monitoring a moving subject in an enlarged manner at the center of the screen.

[Brief description of the drawings]

FIG. 1 is a block diagram of a television camera according to the present invention.

FIG. 2 is a screen division pattern set in the television camera according to the present invention.

FIG. 3 is an explanatory diagram of a screen display of a subject imaged by a television camera according to the present invention.

FIG. 4 is a flowchart when a subject to be imaged by the television camera according to the present invention is displayed at the center of the screen.

[Description of Signs] 1 imaging lens, 2 imaging device, 3 correlated double sampling circuit, 4 automatic gain control circuit, 5 A / D conversion circuit, 6 digital signal processing circuit, 7 D / A conversion circuit, 8 amplifier, 9 Microcomputer, 10 drive circuit, 11 video signal enlargement processing circuit.

Claims (3)

[Claims] 1. An imaging lens on which light from a subject enters, an imaging element for photoelectrically converting the light incident from the imaging lens to output a video signal, a driving circuit for driving the imaging element, and the imaging element A digital processing circuit for digitally processing a video signal from the television camera, wherein a screen dividing means for generating an area obtained by dividing a screen of a required size in an image captured by the image sensor; A television camera, comprising: detection means for detecting an amount of change in luminance level and an amount of change in color in each of regions obtained by dividing a screen of a required size generated by the screen dividing unit. 2. An imaging lens on which light from a subject enters, an imaging element for photoelectrically converting the light incident from the imaging lens to output a video signal, a driving circuit for driving the imaging element, and the imaging element A digital processing circuit for digitally processing a video signal from the television camera, wherein a screen dividing means for generating an area obtained by dividing a screen of a required size in an image captured by the image sensor; Detecting means for detecting an amount of change in luminance level and an amount of change in color of each area of the area obtained by dividing the screen of a required size generated by the screen dividing means; and an area obtained by dividing the screen detected by the detecting means. A comparison means for comparing the amount of change in the luminance level and the amount of change in the color of each area by a required field for each area. Mela. 3. An image pickup lens on which light from a subject enters, an image pickup device for photoelectrically converting the light incident from the image pickup lens to output a video signal, a drive circuit for driving the image pickup device, and the image pickup device A digital processing circuit for digitally processing a video signal from the television camera, wherein a screen dividing means for generating an area obtained by dividing a screen of a required size in an image captured by the image sensor; Detecting means for detecting an amount of change in luminance level and an amount of change in color of each area of the area obtained by dividing the screen of a required size generated by the screen dividing means; and an area obtained by dividing the screen detected by the detecting means. Comparing means for comparing the amount of change in the luminance level and the amount of change in the color of each area by a required field for each area; and a comparison result output from the comparing means. Vertical enlarging means for controlling the drive circuit to control the charge transfer timing of the image sensor so as to enlarge the vertical direction of the required image portion; and enlarging the vertical direction of the required image portion by the vertical enlarging means. A television enlargement means for extending a horizontal direction of a required image portion by interpolation in accordance with the above.