JPS6388986A - Moving object tracking device - Google Patents

Abstract

PURPOSE:To calculate more accurately the position of the center of gravity of moving object signals on a picture by stopping outputting as a moving object extraction signal when pulse phase, a succeeding contour signal, changed within check pulse width. CONSTITUTION:Video signals sent from a television camera 1 by a signal conversion circuit 2 are converted to contour video signals. Then, picture image information after a fixed time is compared by a moving object extracting circuit 3 and those different in picture information are extracted as moving objects. Minute movement caused by wind etc. is removed by a tremble signal checking circuit 4. Then, real moving object extraction signals outputted from the tremble signal checking circuit 4 to a controlling section 5. The controlling section 5 generates control signals to a driving section 6 to make the moving objects always caught by the television camera 1. Consequently, signals in a preset tremble checking extent are not inputted to the controlling section 5, and the television camera 1 does not make tracking operation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a moving object tracking device that separates and extracts a moving object from a complex static background screen in an image obtained by an imaging device such as a television camera. be.

BACKGROUND OF THE INVENTION In recent years, as television cameras have become more widespread, their fields of use are expanding to include, for example, surveillance applications, visual applications for industrial robots, and medical education applications. In most of these applications, images were simply played back and confirmed using the screen, but in recent years, in applications such as FA (factory automation), robots, and remote monitoring, it has become possible to use images to determine the imaging angle of the TV camera itself. There are demands for controlling, monitoring specific moving objects, tracking and imaging, etc. Conventionally, there is a method in which a person specifies a moving object on one screen and the object is tracked on the screen.

Problems to be Solved by the Invention However, the system recognizes moving objects on the screen and constantly pans and tilts the camera to track the moving objects on the screen. During installation, there are cases where the desired moving object cannot be accurately tracked due to isometric micro-movement signals generated as electrical signals, such as micro-movement of the pedestal, etc., and characteristics such as afterimages of the imaging camera.

There is a need for a method to differentiate from such micro-motion signals and recognize the position of objects that move significantly on a television screen, and to automatically and continuously track moving objects with a television camera using this position data.

In particular, a moving object image signal is extracted from a continuously occurring television screen by calculation between two screen signals generated at a certain interval, and the position of the moving object is recognized on the television screen from this extracted signal. If a moving object can be reproduced and tracked to the center of the screen using this recognition, if the scene captured by the television camera is an outdoor landscape, the shaking of leaves caused by the wind or the like will also be extracted and recognized as a moving object. In many cases, such a fine movement signal is not necessary. Particularly when tracking and imaging a thick (moving) object on the screen, the micro-motion signal acts as a noise signal on the tracking control signal of the television camera.

Furthermore, when calculating between the 2ii planes, if a slight temporal jitter occurs in one of the signals, even the stationary signal will not disappear completely and a noise-like residual signal will be extracted.

In view of the above prior art, the present invention provides a moving object tracking device that removes microscopic objects such as leaves caused by wind etc. from moving object recognition.

Means for Solving the Problems In order to achieve the above object, the present invention aims to solve the problems by
A first arithmetic circuit extracts only the image information regarding the moving object from the image information and the subsequent second image information; A second arithmetic circuit removes a slight movement signal as a moving object signal, and the deviation between the output of the second arithmetic circuit and a preset tracking and reproduction reference position signal on the image is calculated, and the deviation is calculated for an object that has moved by a certain value or more. and a drive control section for tracking the television camera.

According to the above-described configuration, the present invention does not output a moving object extraction signal when the pulse phase of the subsequent contour signal changes within the blocking pulse width. Can be done more accurately. Furthermore, since the television camera tracks the image of the moving object based on this calculated data, the effect is great.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a moving object tracking device according to an embodiment of the present invention.

In Fig. 1, 1 is tracking a moving object while capturing it as an image (TV camera), 2 is a signal conversion circuit that converts the video signal output from TV camera 1 into a contour video signal, and 3 is a moving object from the contour video signal. 4 is a moving object extraction circuit that performs calculations for object extraction; 4 is a micro-motion signal blocking circuit that further blocks noise-like micro-animal signals generated by wind, etc. from the output of the moving object extraction circuit 3; 5 is a micro-motion signal blocking circuit 4; 6 is a control unit for determining the center of gravity position of the moving object signal for one screen from the output signal, further calculating the deviation from the center of the screen, and generating a control signal proportional to this value. This is a drive unit that drives the television camera 1 to track a real moving object extracted by a control signal.

The operation of the above configuration will be explained below.

First, the signal conversion circuit 2 converts the video signal sent from the television camera 1 into a contour video signal.Next, the moving object extraction circuit 3 compares the image information after a certain period of time to obtain the image information. Extract different objects as moving objects.

Then, a micro-movement signal blocking circuit 4, which will be described later, removes micro-movements caused by wind or the like. Next, the true moving object extraction signal output from the micro-motion signal blocking circuit 4 is transmitted to the control unit 5.
In contrast, in the control unit 5, moving objects are always detected by the television camera.
A control signal is generated to the drive unit 6 so that it can be understood as follows.

As described above, according to this actual case, since signals within the fine movement prevention range set in advance in the fine movement signal prevention circuit 4 are not input to the control unit 5, the television camera 1 does not perform a tracking operation.

In other words, the minute movement reproduction signal 1 that is unnecessary for tracking a moving object, such as the shaking of leaves caused by 7 locusts, can be blocked, making the tracking operation easier.

Next, a more detailed configuration of each block shown in FIG. 1 will be explained.

FIG. 2 is a detailed configuration diagram of the fine movement signal blocking circuit 4. As shown in FIG. In the figure, 21 is a contour video signal sent from the signal conversion circuit 2, 22 is a memory for storing one screen of image signals, 23 is a shift register circuit for phase compensation, and 24 is a one-screen signal read out by the memory 22. 1 or more drawing numbers 22 to 24 in a moving object signal extraction circuit by calculating the image signal and the subsequent image signal.
The configuration belongs to the moving object extraction circuit 3 shown in FIG. Reference numeral 24 denotes a fine movement signal blocking circuit, which is the same as that shown in FIG. Particularly, in the fine movement signal blocking circuit 24, 2
6.27 is a shift register for setting the fine movement prevention range in the horizontal direction of the image, 28.29 is a horizontal and vertical fine movement prevention pulse generation circuit, respectively, 3], 35 is an output signal of each of the above pulse generation circuits, 30 is shift register 36.37
32 and 36 are an AND circuit, and 33 is a vertical shift register.

Next, the operation of the above configuration will be explained based on FIG.

First, the contour signal of the image extracted from the image signal of the television camera 1 includes a moving object and a background image included in the field of view of the camera lens. First, an arbitrary time t is used to extract the contour signal of only the moving object separately from the background image. The one-screen signal input to is stored in the memory 22. Next, the edge continuation screen after t7 seconds is input to the moving object extraction calculation circuit 24 via the registers 23 and 26.

On the other hand, the image signal at the time of "TO" is outputted from the memory 22 in synchronization with the output signal of the shift register 23, and is inputted to the moving object extraction calculation circuit 24 via the shift register 27.

The moving object extraction calculation circuit 24 compares information about one screen at t0 seconds and t1 seconds, extracts only the signal for the moving object, and obtains an output signal 3o.

Shift registers 26 and 27 are provided in order to determine 1/2 of the range for removing minute signals.

Next, the output signal of the memory 22 is input to the pulse generation circuits 28 and 29 for blocking a fine movement signal. This pulse generating circuit 28 is used to block fine movement signals in the horizontal direction of the screen, and the pulse generating circuit 29 is also used to block fine movement signals in the vertical direction.

In this embodiment, there are 256 pixels per horizontal scanning line, and the horizontal pulse width is set to 4 to 6 pixels. Further, the vertical pulse width can be set to 4 to 6 scanning minutes to sufficiently achieve the purpose.

It should be noted that since the pulse generation circuits 28 and 29 are binary pulsed signals outputted from the memory 22, they can be constituted by, for example, a seven-nostable multi-by-wave circuit.

Next, output signals 30 and 31 from the moving object extraction calculation circuit 24 and the pulse generation circuit 28 for blocking a fine movement signal are outputted to the A N D circuit 32 . For example, one pixel width pulse output signal 30
is within the width of the signal 31 set to the pulse width of 4 pixels, the output signal 30 is imaged with the horizontal fine movement signal and is ANDed.
The output signal of the circuit 32 can have a blocking function.

Also, if the pulse river force signal 30 has moved by more than these four pixels, is the signal output from the AND circuit 32 as a movement signal? Make W force.

Further, in the completely stationary background image portion, the moving object extraction circuit 24 calculates so that the output signal 30 does not exist as a signal. However, if noise is superimposed on the subsequent signal, there is a shift in the image due to slight movement from the previous image of the television camera, or there is jitter in one of the signals, it will be output as a slight movement signal.

Furthermore, when controlling the tracking of a moving object included in an image, it is also possible to control the rise of the contour signal between the two screens due to mechanically generated slight movements when comparing the two screens, afterimages of the image sensor after pan-tilting the TV camera, etc. The slight movement signal is AND circuit 32
More will be output.

Therefore, the output signal 35 provides a similar effect in the vertical direction. That is, the shift register 33 has a vertical fine movement signal blocking pulse width of 172 hours,
In the AND circuit 36, if the signal 34 is within the pulse width of the signal 35, it is treated as a vertical fine movement signal and the output from the AND circuit 36 is blocked. Also output signal 3
4 has a phase exceeding the pulse width, the signal of the moving object is imaged and output from the AND circuit 36.

With the above configuration, it is possible to accurately detect a moving object on the screen by eliminating the generation of unnecessary micro-movement signals and position detection errors caused by them.

The moving object extraction arithmetic circuit 24 shown in FIG. 2 may be replaced with an AND circuit 41. as shown in FIG. EX-ru.

Regarding the signal conversion circuit 2, control section 5, etc. shown in FIG.
No. 132, Japanese Patent Application No. 61-34614, etc., a binarized signal of the entire subject is obtained from an image signal obtained by a television camera by a signal generation circuit, and this binarized signal is delayed by a storage circuit. , After extracting a signal of only the moving object by a moving object signal extraction circuit using this delayed signal and the binary signal of the image output from the imaging device, the center of gravity of the moving object is determined based on this signal, It is sufficient to generate a control signal based on the deviation between this center of gravity and the center of the effective screen set in advance to cause the television camera to perform tracking (detailed explanation will be omitted).

Effects of the Invention As described above, the present invention can selectively extract moving object image signals on the screen that are larger than a certain value, and track and image the moving object with a camera. Particularly when capturing images outdoors, it is possible to remove minute movement signals caused by the shaking of leaves, etc., so the tracking control of moving objects by the television camera can be performed more accurately.

In addition, in the case of continuous tracking operation, it is possible to eliminate the generation of a slight movement signal between the front and rear images due to slight movement, play, responsiveness, etc. of the pan/tilt control mechanism of the camera, and it is possible to determine the position of a desired moving object. Furthermore, during the calculation process for extracting moving objects on the electric circuit, calculation errors caused by minute phase shifts such as thick signals in one signal, signal superimposition noise, and camera afterimage effects can be removed.

This results in more accurate detection of the moving object position.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a moving object tracking device according to an embodiment of the present invention, and FIGS. 2 and 3 are circuit diagrams of the same essential parts. 1...TV camera, 2...signal conversion circuit, 3...
・Moving object extraction circuit, 4... Microtremor signal blocking circuit, 5.
...Control unit, 6...Drive unit.

Claims (1)

[Claims] a first arithmetic circuit that extracts only image information regarding a moving object from first image information of a television image and subsequent second image information; and a moving object image that exceeds a preset pulse width of a micromotion prevention pulse signal. A second arithmetic circuit that treats only the signal as a true moving object signal and removes the slight movement signal, and calculates the deviation between the output of the second arithmetic circuit and a preset tracking and reproduction reference position signal on the image, and calculates the deviation of the signal to a certain value or more. A moving object tracking device comprising a drive control unit that causes a television camera to track a moving object.