JPS6033352B2 - Image target tracking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an image target tracking device for tracking a nearby similar object or a target object with a complicated background.

This type of image target tracking device captures a target object with a sensor, extracts a target signal from the video signal output, detects a deviation of the target position from a reference position within the display screen, and
The tracking function is obtained by mechanically driving the imager in a direction that makes the deviation zero. FIG. 1 shows an example of this type of conventional device, in which 1 is a sensor, 2 is a mixer for mixing the target video signal and the tracking gate signal, 3 is a television monitor that displays the target etc. as information, 4 is a target extractor that extracts a target from the video signal obtained from sensor 1; 5 is a target extractor that detects the position of the target within the television monitor display screen and outputs a deviation signal from the reference position within the television monitor display screen; 6 is a servo amplifier that increases the deviation signal; 7 is a drive unit that changes the direction of the sensor 1 according to the output signal from the servo amplifier 6; 8 is a device that determines the target detection area within the screen. This is a gate signal generation circuit for displaying the above area to the gate signal and operator.

That is, sensor 1, target extractor 4, target position detector 5
, the servo amplifier 6, and the drive unit 7 form a negative feedback loop, so that a tracking function can be obtained so that the target always remains at the reference position within the screen even when the target moves.

However, in the conventional device described above, if another object with a similar contrast to the target enters the gate, the target extractor 4 cannot identify it as the target, so the detection of the target position is affected by the other object, and in some cases, tracking There was a drawback that it could not be continued.

The details will be explained below using FIG. 2, FIG. 3, and FIG. 4.

FIG. 2 is an example of a detailed configuration of the target extractor 4.
is a value processing gate generator 10 for setting the processing area for extracting the background video level;
an extraction threshold voltage generator 11 for the purpose of detecting the video level in the area specified by, i.e. the background video level, and extracting the target, from the sensor l with reference to the extraction threshold voltage; This is a comparator that compares and determines the video signals of and outputs only the target signal.

Further, the signal a input to the lower side of the comparator 11 is transmitted to the comparator 11 so that target extraction is performed only within the desired tracking area
This is a tracking processing gate signal for operating the gate signal generator 1, and is input from the gate signal generating circuit 8.

FIG. 3 is an example of a display of an image of a moving target observed on the television monitor 3, and 12 is a tracking gate area designated by the operator.

A signal related to this is generated by the gate signal generation circuit 8 shown in FIG. Also, for convenience, only the inside of 12 is drawn on the display screen. The target (C in the figure) is placed next to another object (B in the figure) to the left with the sky (D in the figure) and the ground (E in the figure) as backgrounds.

At this time, the value processing gate generator 9 selects, for example, A at the edge of the screen as the background video level detection area.

In this case, we have taken an example in which the threshold level is to be detected using the area at the edge of the screen, but it is also possible to use the area at the edge of the gate 12. In any case, it is usual that a region is set in advance to serve as a guide for extracting the target.

Further, it is usual to extract video signals at several points within a set area and perform averaging or the like to obtain a level serving as a threshold value. Therefore, target extraction is performed.
The value generator 10 sends the video level of the A area, that is, the video level corresponding to the empty area, to the comparator 11 as the IJ reference voltage for target extraction. Comparator 1
1 compares the video level in the tracking gate 12 with the IJ reference voltage to extract a target.

However, in a situation where the contrast between the different object B and the target C is at a similar level, the output signal of the target extractor 4 includes not only the signal for the different object B but also the signal for the different object B.

For this reason, the tracking point calculated by the target position detector 5 deviates from the tracking point F of the target object and becomes like point G in FIG. 3, making it often difficult to continue tracking.

This will be explained in more detail with reference to FIG. 4, which uses signal waveforms. FIG. 4 shows the video signal in FIG. 3 as viewed on the day and 1 lines shown in the upper part of FIG. 3, and the video signal for the day's scanning line is shown in FIG. The video signal for the line is shown in Figure 4-b.

The axis of each machine is the time axis, and the vertical axis is the voltage oscillation. The gate region corresponding to 12 in FIG. 3 is located at L in FIG. 4 on the scanning line.
'This corresponds. Also, the thresholds are as shown in Figure 4a and 4.
J. on figure b. By drawing like K, the area below the dotted line is extracted as a target for each of the gates.

However, it is clear that the target within the gate (B in FIG. 3) is also extracted together with C.

As described above, in the conventional apparatus, there is a problem in that even if an attempt is made to extract signals in terms of level, if the bells are the same, nearby similar objects are always processed as targets.

In order to improve the above-described drawbacks of the conventional art, the present invention sets the processing area of the target extractor or target position detector to be close to the shape of the target. The present invention provides an image target tracking device that makes it possible to exclude signals from other objects.

FIG. 5 shows an embodiment of the present invention, and 1 to 5 are the same as the conventional one and have similar functions. Reference numeral 13 denotes a gate signal generation circuit, which differs from the subordinate gate signal generation circuit 8 in that it generates a gate signal by referring to the contents of the tracking gate shape memory circuit 14.

The tracking gate shape memory circuit 14 determines the position specified by the operator with a cursor (or marker) on the screen as the target extraction area, on what scanning line in the vertical direction and in what position in the horizontal direction on the screen. This is a circuit that stores 1-bit information in a memory corresponding to an address on the screen. Reference numeral 15 denotes a pointing device, which is a man-machine interface for specifying the shape of the tracking cable shape memory circuit 14 by the operator while looking at the V monitor, and is a pointing device, such as a joystick, a track ball, a mouse, etc. is used.

FIG. 6 shows an example of the configuration of a tracking gate shape memory circuit,
16 is an A/D converter for converting the pointing device signal into an address corresponding to the screen; 17 is the A/D converter for converting the pointing device signal into an address corresponding to the screen;
This is an address register for temporarily storing the output signal of the A/D converter 16, and the contents are rewritten and held in correspondence with the conversion cycle of the A/D converter 16.

This address represents the boundary point of the closed area specified by the operator, and as the operator moves the pointing device to specify the processing area that the operator wants to track, this register will contain the movement of the pointing device. 'As time goes on, the address corresponding to that screen will be stored. Reference numeral 18 denotes an address counter, which has contents corresponding to a raster scan address used to image a scene in the outside world with a sensor and an address on the screen of the TV monitor 3. Reference numeral 19 denotes a selector, which switches so that a system signal from the pointing device can be obtained as an output during the retrace period when the operator desires to modify a specified area.

In situations where the operator determines that there is no need to make any corrections, the selector always outputs the signal from the address counter 18. Reference numeral 20 denotes a memory for storing an operator designated area pattern, in which data is written to an address corresponding to the output signal of the selector 19 and data is read from an address corresponding to the output of the address counter 18.

The logic state is constantly 1 outside the input data, and a pattern of 1 is written into the memory by the operator's tracking area setting. The output data of the memory is sent to the gate signal generation circuit 13 in order to generate a tracking gate and a signal for displaying its area. Note that ID is input data, OD is output data, SS is the selector switching signal, and SS2 is REA.
This is a D/WRITE switching signal. Next, the apparatus according to the present invention including the tracking gate shape memory circuit shown in FIG. 5 will be explained using an example of FIG. 7. Fig. 7 is an example of a moving target image observed on the television monitor 3, where 21 is the tracking gate area specified by the operator, and the target to be tracked (C in the figure) is a different object (B in the figure) and other objects. To the left next to another object (1.J in the figure), the sky (D in the figure) and the ground (
Assume that the object is moving with E) in the figure as the background.

At this time, the value processing gate generator 9 selects, for example, A at the edge of the screen as the background video level extraction area. Since the tracking gate area 21 designated by the operator has a shape and size similar to the target C desired to be tracked, the influence of other surrounding objects can be minimized.

Therefore, the target center of gravity can be maintained at a value very close to an ideal state with no surrounding objects. As described above, the tracking gate shape memory circuit 14 and the pointing device 15 are added to the conventional device, and the tracking gate shape memory circuit 14 and the pointing device 15 are added to the conventional device, and the tracking gate is By adding the function of referring to the output signal of the shape memory circuit 14 to the gate generation circuit 13, it is possible to track a target object with close contrast or a complex background in the vicinity, which was difficult with conventional devices. A target tracking device can be realized.

Note that in the above explanation, the output of the gate signal generation circuit 13 is introduced into the target detector 4, but the target position detector 5
It is clear that the same effect can be obtained if 13 outputs are introduced into.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional image target tracking device, Fig. 2 is a subordinate image target tracking device, Fig. 3 is a conventional image target tracking device, and Fig. 4 is a two-dimensional diagram of the image shown in Fig. 3. Signals corresponding to the scanning lines of a book are shown in waveforms, and FIG. 5 shows an example of an image target tracking device based on an embodiment of the present invention, FIG. 6 shows an example of the configuration of a tracking gate shape memory circuit, and FIG. 7 shows an example of the configuration of a tracking gate shape memory circuit. is an example of an image of a moving target observed on the television monitor 3. In the figure, 1 is a sensor, 2 is a mixer, 3 is a TV monitor, 4 is a target extractor, 5 is a target position detector, 6 is a servo amplifier, 7 is a drive section, 8 is a gate signal generation circuit, and 9 is a threshold Value processing gate generator, 10 is an extraction threshold, value generator, 11 is a comparator, 12 is a tracking gate, 13 is a gate signal generation circuit, 14 is a tracking gate shape memory circuit, 15 is a pointing device, 16 is an A /D converter, 17 is an address register, 18 is an address counter, 19 is a selector, 20 is a memory, 21 is a tracking gate, A is a background video level detection station, B is another object, C is a target object, D
is the sky, B is the ground, day is the target tracking point position, 1. J is a different object. It should be noted that the same or corresponding parts in the figures are indicated by the same reference numerals. Tazutazutazzuba3Kyotamuzutakutakutatuta5tazuta7foot

Claims (1)

[Claims] 1 A sensor that images a target object, a target extractor that extracts the target object from the video signal obtained from this sensor, and a target extractor that detects the position of the target on the display screen and outputs the deviation from the reference position of the display screen. An image target tracking device comprising a target position detector, a drive mechanism that receives the output of the detector and controls the direction in which the sensor moves, and a display device that displays a captured image of the target object. In,
A tracking system is provided with a memory circuit for storing the position specified by the operator on the display screen as a target extraction area as address correspondence information on the display screen, and a man-machine interface for storing the operator's specification in the memory circuit. The desired region is displayed as a marker representing the boundary on the display screen, and the operating range on the display screen of the target extractor or target position detector is manually set by the operator to specify and modify the shape to be similar to the target. An image target tracking device characterized by: