JPH04119481A - Method and device for processing target picture - Google Patents

Abstract

PURPOSE:To easily remove a background part by forming a digital video signal obtained from a video signal into a histogram data, removing the signal of the background part from the digital video signal by a look-up table and calculating the center of gravity for a target in a target area. CONSTITUTION:The digital video signal obtained from the video signal outputted from an image pickup camera 1 is formed into the histogram data by a histogram processing circuit 8, and a work data obtained by working this histogram data is transferred to a look-up table 19. In this look-up table 19, the signal of the background part is removed from the digital video signal, and the center of gravity for the target in the target area is calculated. Thus, even when the density distribution of the background part is complicated, the target can be segmented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a target image processing method and apparatus, and in particular,
The present invention relates to novel improvements for identifying or tracking targets such as handling robots, palletizing robots, monitoring devices, foreign object inspection devices, defect inspection devices, aircraft, etc. with high accuracy by using histogram processing.

[Prior Art] In general, an image tracking device includes an imaging device that captures an image including a target to be tracked and outputs a video signal of this screen in time series, and a center of gravity position of the target in the screen captured by this imaging device. The imaging device is equipped with an image processing unit that calculates the deviation from the screen white reference position, and rotates and tilts the imaging device so that the center of gravity position of the target on the screen at the next time matches the screen white reference position, and displays the target in real time. For example, Japanese Patent Laid-Open Nos. 55-149064 and 561
This method has been proposed as Publication No. 16387 and Japanese Utility Model Application No. 61154996.

By the way, in order to track the target in real time, it is necessary to calculate the deviation between the center of gravity position of the target and the screen white reference position in real time. For example, the target image processing device shown in FIG. Proposed.

The target image processing device shown in FIG.
For example, monitor 1 in Figure 9 is displayed on the screen captured with D camera].
As shown in Figure 0, a window W consisting of a target window T and multiple background windows A to D is set, and the target is separated from the background by utilizing the potential difference (contrast) between the video signals of the target and the background. There is a way to extract it. That is, when the first screen is captured by the CCD camera 1, the video signal 1 from the CCD camera 1,
a passes through the differential buffer 3 at the timing of the timing generator 2, and is converted to an A/D converter (analog-to-digital converter) 4.
is converted into a digital signal 4a with a gray scale of 0 to 255,
Noise is removed by the filter 5, and the resultant signal is output to a wind threshold detection section 6 and a black/white target threshold detection section 7. At the same time, a window signal from the XY twin wind signal generator 8 is sent to each of the detectors 6 via the interface 9 and the bus 11 at the timing of the timing generator 2.
, 7.

The window threshold detection section 6 calculates the average value of the density of the pixels within the window W, and the white/black target threshold detection section 7 calculates the maximum value and minimum value, and each of them is sent to the microprocessor via the bus 11. 1
2 is output. The microprocessor 12 calculates an average value + k (maximum value - average value) representing white and an average value k (average value - minimum value) not representing black, and calculates a white target threshold value and a black target threshold value, respectively. These are outputted to the target extracting section 13 as a pewter type signal and a point target signal. At that time, each of the above-mentioned persons must be aware that the targets are, for example, a white target 14 and a black target 15 as shown in FIG.
, it is calculated as shown in FIG.

The setting of each of the threshold values to the target extraction unit 13 is performed by opening a window W on the screen captured by the CCD camera 1.
is set, this is done while the screen is being scanned, that is, in real time.

In addition, when a screen at the next time is captured, for example, 1/60 seconds after capturing the first screen, the video signal of this screen is converted into a digital signal with gray scales of 0 to 255 in the same manner as described above. and is taken into the target extraction section 13. In this target extraction section 13, the density of the pixels within the window W set by the XY twin-wind signal generation 8 is compared with each threshold value, and the video signal of each pixel is binarized.

This allows the target to be separated and extracted from the background. Further, the binarized video signal of the target is taken in in real time by the center of gravity detection section 14, and the position of the center of gravity of the target is calculated. Then, the microprocessor 12 calculates the deviation between the target gravity center position and the center of the window W, which is the screen white reference position, and outputs it as a tracking position deviation signal.

Thereafter, the extraction of the target, the calculation of the target's center of gravity position and the deviation between the target's center of gravity position and the center of the window W are performed in the same way for each captured screen, but these operations are performed until the next screen is captured. It will be held in

[Problems to be Solved by the Invention] Since the conventional target image processing apparatus was configured as described above, the following problems existed.

That is, in the conventional configuration, for example, as shown in Figure 12A and Figure 1.2B, the L○ and UP values of the window comparator are set by determining the maximum value, minimum value, and average value of the image. and L〇-G ave
-K ・(Gave -G L○), UP-Gave
+ K (G U P -Gave), and thus,
Separation is achieved by binarizing.

In other words, as shown in Figure 12A, it is easy to separate field 6 where the background image distribution is simple, but when the background image is complex as shown in Figure 7, it may be misrecognized. .

Therefore, the white target threshold value and black eye source threshold value for extracting the target are set based on the average value, maximum value, and minimum value of the density of pixels within the window W, and are the density of the target itself. Therefore, the present invention was made in view of the above-mentioned conventional situation, and its purpose is to improve the accuracy of the target by using histogram processing even when the background histogram distribution is complex. It is an object of the present invention to provide a target image processing method and apparatus that can extract images well and improve the accuracy of detecting the position of the center of gravity of the target, the accuracy of tracking the target, and the like. [Means for Solving the Problems] A target image processing method according to the present invention creates a target region and a background region using a composite video signal output from an imaging camera and a position setting signal, and creates a target region and a background region from a video signal of the composite video signal. The resulting digital video signal is
- The center of gravity of the target in the target area is determined by converting it into histogram data through gram processing and transferring the processed data obtained by processing the histogram data to a look-up table circuit to remove the background part. This is a target image processing method characterized by the following.

Further, a target image processing device according to another invention includes an area setting circuit that sets a target area and a background area using a composite video signal output from an imaging camera and a position setting signal, and a video signal obtained from the composite video signal. a histogram processing circuit for receiving the histogram data as a digital video signal, a processing means for processing the histogram data from the histogram processing circuit, and a look for inputting the processed data from the processing means and the digital video signal. This configuration includes an up-table circuit and an integration circuit connected to the look-up table circuit.

More specifically, the configuration includes a sync signal separation circuit for inputting the composite video signal, and a counter circuit connected to the sync signal separation circuit and the area setting circuit. X-direction position signal (QX) and Y-direction position signal (
QY) is input to the area setting circuit.

More specifically, the area setting circuit is connected to a setting device containing a plurality of position setting signals.

More specifically, the processing means includes a square root calculation circuit, an integration circuit, a counter circuit, a latch circuit, a clip circuit, and a subtraction circuit.

[Function] In the target image processing method and device according to the present invention,
A digital video signal obtained from a video signal output from an imaging camera is converted into histogram data by a histogram processing circuit, and processed data obtained by processing this histogram data is transferred to a look-up table circuit.

This look-up table circuit removes background signals from the digital video signal and determines the center of gravity of the target in the target area.

Therefore, even when the density distribution of the background part is complicated, the target can be extracted by His1-Gram processing.

[Embodiments] Hereinafter, preferred embodiments of the target image processing method and apparatus according to the present invention will be described in detail with reference to the drawings.

Note that the same or equivalent parts as in the conventional example will be described using the same reference numerals.

1 to 6 and FIG. 12B are for illustrating the target image processing method and apparatus according to the present invention.
The figure is a block diagram showing the overall configuration, Figures 2A to 2E are configuration diagrams showing examples of target windows and background windows, Figures 3A to 3C are waveform diagrams showing histograms, and Figure 4 is timing diagrams. Waveform diagram of signal LT, etc.
Fig. 5 is a block diagram showing the state reproduced on a monitor, Fig. 6 is a block diagram showing an aircraft tracking device to which the target image processing device according to the present invention is applied, and Fig. 2B shows the background part from the target part. FIG. 3 is a waveform diagram showing a state of separation and removal.

First, in FIG. 1, the reference numeral 1 is an imaging camera such as an ITV camera, and a composite video signal 1a from this imaging camera 1 is input to a synchronization signal separation circuit 2. The video signal 2a of
It is input to the A/D converter 3.

The synchronization signals VDHD and OD/EV from the early synchronization signal separation circuit 2 are synchronized with the tarock signal D from the first oscillator 4.
It is input to the first counter circuit 5 to which CLK is input.

X-direction position signals QX and Y from the first counter circuit 5
The direction position signal QY is the position setting signal XTS, XTE, Y.
TS, YTF, , XBS, XBE.

The background window area signal BGATE for setting the background window area from this area setting circuit 7 is input to the area setting circuit 7 which has built-in YBS and YBE and is connected to the saw setting device 6. 8
has been entered.

The histogram processing circuit 8 includes the A/D converter 3.
The digital video signal G F from , the clock signal D CLK , and the synchronization signals VD and HD are input,
Sawtooth wave signals G and D from a second counter circuit 10 connected to a second oscillator 9 are input.

The histogram store Fl! Frequency distribution processing of circuit 8 (
Histogram processing) The histogram data NH of f& is input to the square root calculation circuit 11 for data compression, and the calculation result NHR from this square root calculation circuit 11 is
A clear signal CLR and a clock signal CLK from the counter circuit 10 are input to an integrating circuit 12 and a clip circuit 13.

The integration output A from the integration circuit 12 and the addition output B from the addition section 14 are input to a division circuit 15.
The division output C from 5 is input to a latch circuit 16 to which the timing signal LT from the counter circuit 10 is input.

The average value Gave of the image intensity from the latch circuit 16 is inputted to the clipping circuit 13 as a signal α·Gave via the averaging circuit 17, and this signal α·Gave and the output signal 13a from the clipping circuit 13 are The subtraction circuit 18 subtracts the signal α·G ave, and the output signal 18a of this subtraction circuit 18 is the clock signal CL.
K, digital video signal GH and sawtooth signal G
D is input into one lookup table circuit.

The aforementioned square root calculation circuit 11. Second counter circuit 10, integration circuits 1, 2 . Latch circuit 16. The histogram data NH
It constitutes a machining element u20 for machining.

The target image signal Go from one of the look-up table circuits is directly input to the first integration circuit 22, and is also input to the first multiplier 20 and the second multiplier 21,
The first multiplier 20 receives the X-direction position signal QX, and the second multiplier 21 receives the Y-direction position signal QY.
is entered.

Output signal 20a of each multiplier 20.21.

21a is input to the second integration circuit 23 and the third integration circuit 24, and each integration circuit 22, 23, 24 receives the target window area signal TGATE for setting the target area from the area setting circuit 7 and the target window area signal TGATE for setting the target area from the area setting circuit 7. A clock signal DCLK is input.

The first VT calculation output B from the first integration circuit 22 and the second integration output A from each integration circuit 23. input to the second division circuit 25.26, each division circuit 25.2
The division output C from 6 is input to the first and second latch circuits 27.28 to which the synchronization signal VD is input, and each latch circuit 27.28 outputs the center of gravity position signal xz,
xy is output.

The target image processing device according to the present invention is configured as described above, and its operation will be explained below.

First, the imaging camera 1. The composite video signal 1a from V is separated into a video signal 2a and a synchronization signal V
It is separated into D, HD, and OD/EV.

These synchronization signals VD, HD, ○D/EV and tarok signal D
By inputting CLK to the counter circuit 5,
An X-direction position signal QX and a Y-direction position signal QY on the screen shown in FIG. 2 are created.

By inputting the X-direction position signal QX, the Y-direction position signal QY, and the position setting signal XTS□-YBE from the setting device 6 to the area setting circuit 7, two target window areas T G A T E and a background window area BGAT are set.
E is created and these areas TGATE BGATE
When is active, it indicates that the target 40 is located within the target window and the background window, as shown in FIG.

Examples of these set target windows and background windows are shown in FIGS. 2A to 2E.

Next, the aforementioned video signal 2a is converted into a digital video signal GF by the A/D converter 3, and this digital video signal GF is combined with the aforementioned signal BGATE, synchronizing signals VD, H
D and tally signal DCLK are input to the histogram processing circuit 8, and this histogram processing circuit 8
Using these signals, a frequency distribution (histogram) NH for the image signal strength GD is created as shown in FIGS. 3A to 3C.

Further, the clock signal CLK from the second oscillator 9 is input to the second counter circuit 10, and the sawtooth image intensity GD, timing signal LT, and clear signal CLR shown in FIG. 3A are created.

In synchronization with the image intensity GD, a histogram processing circuit 8
The histogram data N H output from is compressed by a square root calculation port I¥811, and the distribution frequency NHR of the processing result is obtained.

This processing result NHR is input to the integration circuit 12, and the image intensity GD is cumulatively added in the range O to GMX in synchronization with the clock signal CLK, as shown in FIGS. 3A to 3C. This taken data passes through a division circuit 15 and a latch circuit 16, and is then converted to the average value Gave of the image intensity GD.
is taken.

Therefore, the histogram of FIG. 3A shows that the clip circuit 13
As shown in FIG. 3B, clipping is performed to α·Gave to obtain clipped output NC, and this clipped output NC
is subtracted by the subtraction circuit 18, and the internal data GL(
Figure 3C) is created.

This internal data GL physically indicates the degree to which the digital video signal GF is a target signal.

The one look-up table circuit converts the digital video signal GF into a target image signal GO, which target image signal GO has already been weighted with respect to the degree of being a target image, and the background image has been removed. has been done.

Next, this target image Go is calculated by the first integration circuit 22 in the target window to obtain ΣGo.

Similarly, the first arithmetic unit 20 and the second integration circuit 23 calculate ΣG0QX during the target window, and the second multiplier 21 and the third integration circuit 23 calculate ΣG during the target window.

Calculate QY.

Next, the first divider 25 calculates (ΣGOQX)/ΣGo
is calculated, the center of gravity xZ in the X direction is derived, and the second divider 26 calculates (ΣG○・QY)/ΣGo,
The center of gravity YZ in the Y direction can be derived.

Further, FIG. 6 shows the application of the target image processing bag W50 as a visual sensor according to the present invention to an aircraft tracking device 51, in which a composite video signal 1a from an imaging camera 1 is obtained.
are input to the target image processing device 50, and the center of gravity position xz,
yz is converted by a polar coordinate conversion circuit 52, and deviation data αZ and βZ are output from this polar coordinate conversion circuit 52.

These deviation data αZ and βZ are input to the vertical rotation direction servo motor 55 and the rotation direction servo motor 56 via a pair of servo amplifiers 53 and 54, and control the position of the imaging camera 1 in the α direction and the β direction. Is going.

[Effects of the Invention] Since the target image processing method and apparatus according to the present invention are configured as described above, the following effects can be obtained.

That is, the digital video signal obtained from the video signal is converted into histogram data, the background signal is removed from the digital video signal using a look-up table circuit, and the center of gravity of the target in the target area 1 is determined. Even in the case of a complex density distribution of the background part as shown in Fig. 12B, the background part can be removed very easily.

[Brief explanation of drawings]

1 to 6 and 12B are for showing the target image processing method and apparatus according to the present invention.
The figure is a block diagram showing the overall configuration, Figure 2A, Figure 2B,
2C, 2D and 2E are block diagrams showing examples of target windows and background windows;
Figures 3B and 3C are waveform diagrams showing histograms, Figure 4 is a waveform diagram of timing signals LT, etc., and Figure 5
The figure is a configuration diagram showing the state of the image reproduced on the monitor.
The figure is a block diagram showing an aircraft tracking device to which the target image processing device according to the present invention is applied, and Figure 1.2B shows Targetera 1.
Waveform diagram showing a state in which the background portion is separated and removed from the bottom portion, No. 7
The figures from Figure to Figure 12A are for showing the conventional configuration.
FIG. 7 is a waveform diagram showing the separation and removal of the background portion from the target portion, FIG. 8 is a block diagram, and FIGS. 9 and 10.
The figure is a monitor image configuration diagram, Figure 11 is a waveform diagram, and Figure 12A is a waveform diagram.
The figure is a configuration diagram showing a state in which a background part is separated from a target part. 1 is an imaging camera, 1a is a multiple video signal, X'TS~Y
BE is a position setting signal, 2a is a video signal, NH is histogram data, TGATE is a target area, BGATE is a background area, GF is a digital video signal,
5 is a counter circuit, 7 is a region setting circuit, 8 is a histogram processing circuit, 10 is a counter circuit, 11 is a square root calculation circuit, 12 is an integration circuit, 13 is a clip circuit, 1 is a look-up table circuit, 20 is a processing means , QX is an X-direction position signal, and QY is a Y-direction position signal.

Claims (5)

[Claims] (1), the target area (TGATE) and background area (BGA
A digital video signal (GF) obtained from the video signal (2a) of the composite video signal (1a)
Histogram data (NH
), and the processed data obtained by processing the histogram data (NH) is processed into a look-up table circuit (19).
A method for processing a target image, characterized in that the center of gravity of the target in the target area is determined by transferring the image to the target area and removing the background part. (2) The target area (TGATE) and background area (BGA
a histogram processing circuit (8) for accepting the video signal (2a) obtained from the composite video signal (1a) as a digital video signal (GF); Processing circuit (
a look-up table circuit (19) for inputting the processed data from the processing means (20) and the digital video signal (GF); ), and an integration circuit (19) connected to the lookup table circuit (19).
22), wherein the look-up table circuit (19) removes a background signal from the digital video signal (GF) to obtain the center of gravity of the target in the target area (TGATE). Characteristic target image processing device. (3) a synchronization signal separation circuit (2) for inputting the composite video signal (1a); and a synchronization signal separation circuit (2) for inputting the composite video signal (1a);
) and a counter circuit (5) connected to the area setting circuit (7), and the X-direction position signal (QX) and Y-direction position signal (QY) from the counter circuit (5) are connected to the area setting circuit ( 7). The target image processing device according to claim 2, wherein (4) The target image according to claim 2 or 3, wherein a setting device (6) containing the position setting signal (XTS to YBE) is connected to the area setting circuit (7). process. (5) The processing means (20) includes a square root calculation circuit (1
Claim 1 characterized in that it is comprised of: 1) an integration circuit (12), a counter circuit (10), a latch circuit (16), a clip circuit (13), and a subtraction circuit (18).
5. The target image processing device according to any one of 4 to 4.