JPS6063475A - Picture tracking device - Google Patents

Abstract

PURPOSE:To make stable tracking and search possible by switching automatically light quantity control between light quantity control based on an average luminance in a screen and that based on an average luminance in a gate in accordance with a tracking state signal to pick up the image of a tracking target quickly in an optimum light quantity state. CONSTITUTION:An incident light has the quantity adjusted by an optical stop 8, and the image is converted to an electric video signal by a sensor 9 and is supplied to a tracking target extracting part 10 to detect the position of the target, and a tracking gate 4 is set around a target 3, and an average voltage level in the tracking gate 4 is detected by an intra-gate average voltage level detecting part 12. When tracking is not performed, a stop controller 13 uses an average voltage outputted from an intra-screen average voltage level detecting part 11 to control the optical stop 8. When a tracking indication signal 17 is outputted through an operation panel 15, a state signal is transmitted from a microcomputer 16 to the stop controller 13 to switch automatically light quantity control.

Description

[Detailed description of the invention] [Technical field of invention] This invention relates to an improvement in a single image tracking device.

[Prior art]

The image tracking device uses the difference in brightness between the target and the background to
This is to extract the target. The external conditions to which the image tracking device is applied are weather conditions for 9 hours.

It varies depending on the location, etc., and the image on one screen also changes variously depending on the situation. Therefore, in order to always obtain optimal images, it is necessary to adjust the amount of incident light using an optical aperture. Hereinafter, the operation of a conventional device of this type will be explained in detail using FIG.

FIG. 1 is a diagram explaining the screen display, and fl) is the full screen.

(2) is the background, (3) is the target, (4) is the tracking gate, (
5) is a scanning line. In order to keep the brightness level of the video on the screen almost constant over time, generally, the average value of the brightness of the video signal is measured, and then the average value of the brightness of the video signal is measured, and
Light amount control is performed by applying feedback to the optical diaphragm.

By the way, as shown in the figure below, tracking is performed using the tracking game l-+
41, it may not always be optimal to measure the average brightness of the entire screen and perform the light amount control during tracking.

In Figure 1, for example, the background (2) has a large area.

It is assumed that the brightness is low and the target (3) has a small area and high brightness.

FIG. 2 is a diagram showing the video signal of the scanning line (5) when the optical aperture is controlled based on the average brightness of the entire screen in the above case. In the figure, (2a) is the background signal, (3a
) is the target signal, and (6) is the average voltage level of the entire screen.

In this case, the overall average voltage level decreases due to the background (2) with low brightness, so the Bummagical aperture is controlled to increase its opening. As a result, the amount of incident light becomes too large and the upper limit of the target signal (3a) is crushed, so S
The ratio deteriorates, making it difficult to identify targets and making tracking unstable.

To deal with such drawbacks, conventionally, during tracking, the optical aperture is controlled using the average brightness within the tracking game 1-(41) including the target (3).

FIG. 3 is a diagram showing the video signal of the scanning line (5) when the optical aperture is controlled using the average brightness within the tracking game 1-+41. In the same figure (2b
) is the background signal, (3b) is the target signal, (4a) is the gate position, and (7) is the average voltage level within the gate. In this case, the average voltage level within the gate is large due to the high brightness target (3), and as a result, the optical diaphragm is controlled to reduce its opening, so the voltage level of the background signal (2b) is suppressed. , the SA ratio of the target signal (3b) has improved to 9
The amount of incident light becomes suitable for tracking.

However, when not being tracked, game! - If the optical diaphragm is controlled based on the average brightness, it will generally be difficult to see both sides as a whole, which may cause some inconvenience when searching for a target. Figures 4 and 5 are diagrams showing one example. Figure 4 is a diagram showing a video signal for one line when the optical diaphragm is controlled by the average luminance within the gate, and Figure 5 is a screen in this case. It is a figure which shows an example of a display. In Fig. 4, (2c) is the background signal,
(3c) is the target signal. Game 1 as shown in Figure 5
- (When most of 41 is included in the high-brightness background (2), the optical aperture is controlled so that the incident scene becomes small according to the average brightness of the high-brightness background. In this case.

As shown in FIG. 4, the target signal (3c) in the low voltage level portion is suppressed and the S-ratio deteriorates.

In this way, if you want to image a target under always good conditions, it is necessary to switch between control based on the average voltage level of the whole screen and control based on the average voltage level within the gate depending on when tracking or non-tracking. I understand.

FIG. 6 shows an example of a conventional flattening device. In the figure (
8) is the optical aperture, C9) is the sensor, 1101 is the tracking target extractor, on is the average voltage level detector in the screen,
a7J is a gate average voltage level detection unit, (131 is an aperture controller, αa is an aperture drive unit, and (151 is an operation panel.) The amount of incident light is adjusted by an optical aperture (8).

The image on the sensor (9) is converted into an electrical image signal by the sensor 19). The converted video signal is supplied to the tracking target extraction section 11G, a target signal is extracted, and the position of the target is detected. Based on the position information of the detected target, the tracking game 1-+41 locates the target (3) as shown in Figure 1.
), and the average voltage level within the tracking gate (4) is detected by an in-gate average voltage level detection section (Inc.). Further, the average voltage level within the screen is detected by the average voltage level detection unit al on both sides using the video signal output from the sensor 19+. The output of these in-screen average voltage level detectors (Ill, gate average voltage level detector @) can be determined by the operator from the operation panel 0 while viewing the 91-screen image.
Selected through 51.

One output is supplied to the aperture controller 03.

The aperture controller uses this output to control the aperture drive unit aI.
J to drive the optical aperture (8).

In this way, with conventional devices, the operator has to manually switch the switch for the above-mentioned selection, which not only makes the operation complicated and puts a heavy burden on the operator, but also As mentioned above, tracking becomes unstable due to erroneous operations such as controlling the optical aperture 191 based on the average brightness within one surface, or conversely controlling the optical aperture 191 based on the average brightness within the gate when tracking is not being performed. It had the disadvantage that it could lead to situations where it was difficult to conduct a search.

[Required of the invention]

The invention is based on the operation panel (15+).
'rl: has been abolished and the tracking status signal is used to automatically switch between light amount control based on the average luminance within the screen and light amount control based on the average pancreatic intensity within the gate, thereby eliminating these drawbacks. be.

[Embodiments of the invention]

FIG. 7 shows one embodiment of this invention.
(16) is a microcomputer, and α is a tracking instruction signal. The functions of (8) to Oa are the same as those of conventional devices, so their explanation will be omitted.

In Fig. 7, when non-tracking, the aperture controller αJ is 9
The optical diaphragm (8) is controlled using the average voltage output by the screen average voltage level detector.

When the operator manually sets the tracking gate (4) to surround the target (3) as shown in Figure 1 via the damage panel (2) and outputs the tracking instruction signal aη, this The signal is read by the microcomputer (161).

The status signal is transmitted from the microcomputer a0 to the aperture controller α4, and the light quantity control is automatically switched.

〔Effect of the invention〕

As described above, in the device according to the present invention, the microcomputer reads the tracking instruction signal, and controls the amount of light based on the average voltage level within the nine screens and the scene control based on the average voltage level within the gate, depending on the two types of states (search/tracking). However, since it is automatically switched, it is possible to quickly image the tracking target under the optimal light intensity condition, which not only enables stable tracking and searching at all times, but also reduces the complexity of manual operation. Therefore, it can greatly contribute to quick and reliable tracking operations.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the screen display, Figure 2 is a diagram showing the video signal when the amount of light is controlled by the average voltage level within the screen,
Figure 3 is a diagram showing the video signal when the light intensity is controlled by the average voltage level inside the gate, Figure 4 is a diagram showing the video signal when the scene is controlled by the average voltage level inside the gate during non-tracking, FIG. 5 is a diagram showing a screen display during non-tracking, FIG. 6 is a diagram showing an example of the configuration of a conventional image tracking device, and FIG. 7 is a diagram showing an actual example of the configuration of the image tracking device of the present invention. So, (1) is full screen, (2) is background, (3) is target, (4
) are tracking gates, (2a), (2b), (2c)
is the background signal, (3a'). (3b), (3c) are eye-catching signals, (4a), (4
b) is the gate position. (6) is the average voltage level in the screen, (7) is the average voltage level in the gate, (8) is the optical aperture, C9) is the sensor,
1llB is a tracking target extraction unit, and Qll is a bell detection unit that measures the average voltage within the screen. @ is the gate average voltage level detection section, Q31 is the aperture controller, aω is the aperture drive section, and α9 is the operation/tunnel. α0 is a microcomputer, and anl is a tracking instruction signal. Note that in FIG. 9, the same or corresponding parts are denoted by the same reference numerals. Agent Masuo Oiwa Figure 1 Figure 2 a a Figure 3 Figure 4 c 3 Figure 6 L5 q /θ Figure 7

Claims (1)

[Scope of Claims] An image tracking device comprising a sensor that images a target object using an optical detection element such as visible light or infrared light, and a target detection unit that extracts a target signal from a video signal obtained from the sensor. A first means for measuring the brightness of the entire screen, a second means for measuring the brightness within the gate surrounding the target, and an average value of the brightnesses measured by the first or second means. A third means for driving the optical diaphragm of the sensor so as to maintain a constant value, and a fourth means for selecting the first means when the target is not being tracked and the second means when the target is being tracked. An image tracking device characterized by: