JP3480803B2 - Moving target detection processing apparatus and method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup device used as a target detection unit of a guided missile, for example,
The present invention relates to a moving target detection processing apparatus and method for detecting a moving target included in a captured image by using moving image processing, and particularly when a result detected as a moving target expands or splits with respect to an actual moving target. In addition, it is used to correct and obtain accurate moving target detection.

[0002]

2. Description of the Related Art Generally, in an image pickup device used as a target detection unit for a guided missile or the like, when a target included in a visible / infrared image is detected by using moving image processing, it is continuous in time. The two images are compared to detect a changed portion as a moving body.

That is, in the above detection method, the images at times t and t-1 are set as G (t) and G (t-1), respectively, and G (t-1) and G (t) are subtracted. Then, an image in which the value of the still portion such as the background becomes 0 is extracted. Therefore, it is possible to detect a portion having a certain value in this image as the moving target.

However, in the above detection method, as shown in FIG. 3, an image K obtained by subtracting G (t-1) and G (t) is obtained.
At t, in addition to the actual movement target part in G (t) (shaded part in the upper right of FIG. 3), the movement target part in G (t-1) (shaded part in the upper left of FIG. 3) also appears. become.
As a result, the moving target portion appearing in the image K (t) (the shaded area in the lower center of FIG. 3) is expanded by the amount of the moving target portion in the past than the actual moving target portion, and the moving target moves. If the distance is large, it will appear as a split form.

[0005]

As described above, in the conventional moving target detecting method, when the moving target is detected by using the moving image processing, the past moving target portion is expanded or divided according to the detection result. It has the problem of appearing in form.

An object of the present invention is to provide a moving target detection processing apparatus and method capable of detecting an accurate moving target by performing correction for eliminating a past moving target portion from an image obtained in the moving target detection process. Especially.

[0007]

A moving target detection processing apparatus according to the present invention inputs an image pickup signal obtained by an image pickup apparatus, delays the image pickup signal by a time delay corresponding to at least one screen display, and at least 3 units. Time-division means for time-division into a plurality of consecutive image signals and a plurality of image signals time-divided by the time-division means, and the difference operation is mutually performed. To the moving target signal sequence extracted as the moving target signal and the moving target signal sequence obtained by this moving target signal extracting unit, the characteristics of the past moving target components are inverted between the signal sequences. And a moving target expansion component correcting means for extracting only the moving target component at the present time by extracting the matched signal amplitude component based on the comparison result. One in which the.

According to this structure, the image pickup signal obtained by the image pickup apparatus is time-divided into a plurality of three or more consecutive image signals delayed by a time delay corresponding to at least one screen display, and the time-division is performed. By performing the difference calculation on each of the plurality of image signals, a moving target signal sequence in which only the image change component is extracted excluding the still image such as the background is generated. Then, the characteristics of the past movement target components of the movement target signal sequence are inverted and compared with each other, and the matched signal amplitude component is extracted as the current movement target. Therefore, the past moving target component that is expanded or divided and displayed in the display screen is removed, so that the accurate moving target can be detected.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a method in a moving target detection process which is an embodiment of the present invention.

First, an image pickup signal obtained by the image pickup apparatus is delayed by a time delay corresponding to at least one screen display, and at least three or more consecutive image signals G (t-2),
It is time-divided into G (t-1) and G (t). Next, the time-divided image signals G (t-2), G (t-1), and G (t) are subjected to, for example, difference calculation with respect to the image signals G (t-2) and G (t-1). , The image signals G (t-1) and G (t) are executed to remove a still image such as a background (dotted line part in the middle part of FIG. 1) to remove an image change component (in the middle part of FIG. 1). The differential signals B (t-1) and B (t) indicating only the shaded portions are generated. Then, the characteristic of one of the difference signals B (t-1) is inverted with respect to these difference signals B (t-1) and B (t), and the difference signal B (t
-1) and the difference signal B (t) are compared to obtain a signal F (t) obtained by extracting only the current movement target component.

FIG. 2 shows a circuit configuration for realizing the above method. First, the image signal G (t) obtained by the imaging device is input to the input terminal 11. The input image signal G (t) is supplied to the delay circuit 1 which constitutes the time division means.
By being supplied to 2, the first delay signal G (t-1) delayed by the time corresponding to one screen display is generated. Further, the first delay signal G (t-1) is supplied to the delay circuit 13 to generate a second delay signal G (t-2) delayed by a time corresponding to one screen display. .

The image signal G (t) input to the input terminal 11 and the first delay signal G (t-1) output from the delay circuit 12 are supplied to the difference calculation circuit 14 respectively. , A difference calculation is performed, and as a result, a first difference signal B (t) obtained by extracting only the image change component is generated,
The absolute value circuit 141 converts the value into an absolute value and the binarization circuit 1
5 is output. Further, the first delay signal G (t-1) output from the delay circuit 12 and the second delay signal G (t-2) output from the delay circuit 13 are respectively supplied to the difference calculation circuit 16. As a result, the difference calculation is executed, whereby the second difference signal B (t-
1), converted into an absolute value by the absolute value circuit 161, and output to the binarization circuit 17.

Here, the binarization circuit 15 sets a predetermined threshold value with respect to the absolute value of the input first difference signal B (t), and outputs a signal component above this predetermined threshold value. H (high)
The binary signal D1 is set to the level, and the signal component less than the predetermined threshold value is set to the L (low) level. Also,
The binarization circuit 17 receives the input second differential signal B (t-1).
The absolute value of is subjected to the same processing as that of the binarization circuit 15 to generate a binary signal D2.

The binary signals D1 and D2 output from the binarization circuits 15 and 17 are compared with the comparison operation circuit 1 respectively.
8 is output. The sign of the binary signal D2 is inverted by the inverting circuit 19. The comparison operation circuit 18 is
Input binary signal D1 and binary signal D2 whose sign is inverted
And a matching H level signal is output to the output terminal 20 as the current movement target component signal F (t).

Therefore, according to the above-described embodiment, the delay circuits 12 and 1 are provided for the image pickup signal obtained by the image pickup apparatus.
3 is time-divided into a plurality of three or more consecutive image signals delayed by a time delay corresponding to at least one screen display,
The difference calculation circuits 14 and 16 respectively perform difference calculation on the plurality of time-divided image signals to generate a moving target signal sequence in which only image change components excluding a still image such as a background are extracted. ing. Then, the characteristics of the past movement target components of the movement target signal sequence are inverted by the inverting circuit 19 and compared with each other, and the matched signal amplitude component is extracted as the current movement target. .

Therefore, the past moving target component which is expanded or divided and displayed in the display screen is removed.
It is possible to detect an accurate moving target. Also, 2
In the binarization circuits 15 and 17, the difference calculation circuits 14 and 1
A predetermined threshold value is set for the differential signals B (t) and B (t-1) obtained in step 6, and signal components above the predetermined threshold value are extracted as the moving target. The value of the image still at the predetermined position is set to 0, and the differential signal including only the moving target is obtained. Note that this threshold value may be variably settable according to the target to be detected.

Further, in the above-described embodiment, the image change component extracted by the difference calculation circuits 14 and 16 may be a change component based on the image brightness difference or the image color difference. It is also possible to extract the current movement target based on this.

The present invention is not necessarily limited to the scope of the above-described embodiment, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0019]

As described above in detail, according to the present invention,
It is possible to provide a moving target detection processing device and method capable of detecting an accurate moving target by performing correction for excluding a past moving target portion from an image obtained during the moving target detection process.

[Brief description of drawings]

FIG. 1 is an image display diagram for explaining an embodiment of a moving target detection processing method according to the present invention.

FIG. 2 is a circuit configuration diagram showing an embodiment of a moving target detection processing device according to the present invention.

FIG. 3 is an image display diagram for explaining a conventional moving target detection processing method.

[Explanation of symbols]

11 ... Input terminal, 12, 13 ... Delay circuit, 14, 16 ... Difference calculation circuit, 15, 17 ... Binarization circuit, 18 ... Comparison arithmetic circuit, 19 ... Inversion circuit, 141, 161 ... Absolute value circuit.

─────────────────────────────────────────────────── ─── Continued Front Page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04N 7/81 F42B 15/01 G01S 3/782 G06T 7/20 H04N 5/232

Claims (6)

(57) [Claims] 1. An image pickup signal obtained by an image pickup device is inputted,
A time division means for delaying the image pickup signal by a time delay corresponding to at least one screen display into at least three or more continuous image signals, and a plurality of image signals time division by the time division means. On the other hand, a moving target signal extracting means for performing a difference calculation on each other and generating an image change component as a moving target signal from each difference result in a moving target signal sequence, and a movement obtained by the moving target signal extracting means. Only the current moving target component is extracted by inverting and comparing the characteristics of the past moving target component with respect to the target signal sequence and extracting the matched signal amplitude component based on this comparison result. A moving target detection processing device, comprising: a moving target expansion component correcting means. 2. The first time division means delays an image pickup signal obtained by the image pickup apparatus by a time corresponding to a single screen display, and the output of the first delay means is displayed on the first screen display. A second delay unit that delays by a corresponding time, and the movement target signal extraction unit performs a difference calculation between the image pickup signal input to the time division unit and the output of the first delay unit. The first to extract the image change component by
Image change component extraction means and second image change component extraction means for extracting an image change component by performing a difference operation between the output of the first delay means and the output of the second delay means. The moving target expansion component correcting means includes an inverting means for converting an output of the second difference computing means into a signal having an inverse characteristic thereof;
The output of the inverting means and the output of the first difference calculating means are compared and calculated, and based on the result of the calculation, the matched signal component is extracted as the current movement target signal. The moving target detection processing apparatus according to claim 1, wherein 3. The movement target signal extraction means further comprises:
A first moving component extracting means for setting a predetermined threshold value for the output of the first image change component extracting means, and extracting a signal component equal to or higher than the predetermined threshold value as the movement target signal; A second moving component extracting means for setting a predetermined threshold value with respect to the output of the second image change component extracting means and extracting a signal component equal to or higher than the predetermined threshold value as the movement target signal. The moving target detection processing device according to claim 2, wherein 4. The moving target according to claim 2, wherein the image change component extracted by the first and second difference calculating means is a change component based on an image brightness difference or an image color difference. Detection processing device. 5. An image pickup signal obtained by an image pickup device is delayed by a time delay corresponding to at least one screen display and time-divided into a plurality of continuous image signals of at least three or more, and then the plurality of image signals are obtained. Image difference components are generated in the extracted moving target signal sequence by performing the difference calculation for each, and the characteristics of the past moving target components are inverted and compared with this moving target signal sequence. The moving target detection processing method is characterized in that only the moving target component at the present time is extracted by extracting the signal amplitude components that are matched with each other. 6. The moving target detection processing method according to claim 5, wherein the image change component is a change component based on a difference in image brightness or a difference in image color.