JPH0519955B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluorescent point detection device for image-measuring the landing position of a fluorescent bullet.

[Conventional technology]

FIG. 3 is a diagram showing the configuration of a conventional flash point detection device. In FIG. 3, 1 is a video signal input from an image sensor, 2 is an A/D converter, 3 is a frame memory, and 4 is a video signal input from an image sensor. Gun firing pulse signal, 5 is a counter, 6 is counter preset data, 7 is a frame memory freeze pulse, 8 is video data, 9 is pixel address data, 10 is a peak point detection circuit, 11A is peak point address data, 11
B is peak level data. Figure 4 is the third
4 is a configuration diagram of the peak point detection circuit shown in FIG. 4, 12 is a data flip-flop circuit, 13 is a comparator, 14A is a frame reset pulse, 14B is a trigger pulse, and 15 is a data flip-flop circuit. It is a circuit.

FIG. 5 is a diagram showing an example of an imaging frame when a reflected light image is captured in saturation over a plurality of pixels, in which 16 is a screen, 17A is a reflected light image, 17B is a background image, and 18A is a captured image. 18B is the pixel with the earliest scanning time among the maximum brightness pixels, and 18B is the pixel with the latest scanning time among the maximum brightness pixels.

The conventional fluorescent spot detection device is configured as described above, and the video signal 1 from the image sensor is sent to the A/D
One frame is constantly written into the frame memory 3 while being converted from analog to digital by the converter 2. On the other hand, the counter 5 is preset with counter preset data 6 representing the flight time to the target distance plane of a shell whose initial velocity is known.

When a shell is fired and passes through the muzzle, a gun firing pulse 4 is input from a sensor such as a pressure sensor to a counter 5 at that time, and preset data 6 is input.
subtraction is started.

When the content of the subtraction result of the counter 5 reaches the beginning of the frame when it becomes less than the data representing one frame time, the counter 5 outputs a frame memory freeze pulse 7 and new writing to the frame memory 3 is stopped. Then, the position of the illuminated light, which is the brightest bright spot, is detected by the method described below.

FIG. 4 is a diagram showing details of the peak point detection circuit 10, in which the video data 8 read from the frame memory 3 is processed by the frame reset pulse 14.
The data is input to the flip-flop circuit 12 which is reset at the beginning of the frame at A, and the comparator 1 is output only when a trigger pulse 14B, which will be described later, is generated.
The signal is transmitted to one input terminal A of 3. The video data of the current pixel is input to the other input terminal B of the comparator 13, and the comparator 13 outputs the trigger pulse 14B only when the input B is greater than the input A. Initially, the data flip-flop circuit 12 has been reset as described above, so input A is O, and for video data input to input terminal B, B is
>A, a trigger pulse 14B is generated, and this video data is sent to the data flip-flop circuit 1.
2 and appears at the input terminal A of the comparator 13.

If the level of the subsequent video data is lower or equal to that of the above video data,
Since B>A does not hold, the trigger pulse 14B is not generated, and therefore, the maximum video data up to now is held in the data flip-flop circuit 12.

When video data at a level exceeding the above-mentioned maximum video data appears at the input terminal B of the comparator 13, the trigger pulse 14B is output again at this time, and this new maximum video data is held in the data flip-flop circuit 12. , and the pixel address data 9 are held in the data flip-flop circuit 15.

In this way, by processing one frame image in the order of scanning, the data flip-flop circuit 12,
15 holds the level and pixel address of the fastest scanning pixel among the maximum brightness pixels, and the peak point address data 11 respectively
A and peak level data 11B.

[Problem that the invention seeks to solve]

By the way, if the fluorescent image is far enough away or the brightness is not significantly higher than the background brightness, the fluorescent image will be captured at a size within about 1 pixel and will be higher than the background. Since it is a luminance, the position of this fluorescent image can be detected correctly using the method described above, but if this is not the case, the fluorescent image will be captured in saturation across multiple pixels, making it difficult to detect the end points of the fluorescent image. There is a problem when it happens.

FIG. 5 shows an example of an imaging frame in such a state. When scanning is performed from the upper left to the lower right of the screen 16, the pixel 18A with the earliest scanning time among the saturated pixels is , will be detected as a peak point.

The present invention has been made to solve this problem, and an object of the present invention is to accurately detect the center of a fluorescent image even when the fluorescent image is saturated with a plurality of pixels.

[Means for solving problems]

The fluorescent spot detection device according to the present invention includes means for storing the pixel addresses of the latest pixel and the earliest pixel of maximum brightness scanning time, and calculating the center of the above two types of pixel addresses. A means for detecting the position of the light spot is provided.

Further, a focused light point detection device according to another aspect of the present invention includes means for determining a threshold value using a peak level detected in a previous frame, and binarizing a processing area of a current frame using the threshold value determined by the means. and means for calculating the center of gravity of the fluorescent image using the binarized video data obtained by the means and detecting the position of the fluorescent light spot.

[Effect]

In the present invention, when the maximum brightness pixel is one pixel, the pixel is detected, and when the pixel is spread over a plurality of pixels, the approximate center of the spread is detected.

Further, in another aspect of the present invention, since the center of gravity near the maximum brightness pixel is found, even if the maximum brightness pixel spreads over a plurality of pixels, the approximate center of the spread can be similarly detected.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention,
In FIG. 1, 8 is video data, 9 is pixel address data representing pixel coordinates in the in-screen orthogonal coordinate system in units of pixel pitch, 11A is peak point address data, 11B is peak level data,
12 is a data flip-flop circuit; 13A is a trigger pulse 14B when input B is larger than input A;
13B is a comparator that outputs a trigger pulse 14C when input B is greater than or equal to input A, 15A, 15
B, 15C is a data flip-flop circuit, 19
is the output of the data flip-flop circuit 15A, 2
0 is the output of the data flip-flop circuit 15B,
21 is an averaging circuit, and 22 is a processing area completion pulse.

The pixel with the highest signal strength is defined as the maximum brightness pixel, and among these maximum brightness pixels, the address of the pixel that is scanned fastest is the address of the data flip-flop circuit 15.
The process obtained at the output 19 of A is the same as that of the conventional device described above, so a description thereof will be omitted. The maximum brightness level of the previous scans is input to the input terminal A of the comparator 13B. Since the comparator 13B continues to output the trigger pulse 14C even when the input B is equal to the input A,
The latest address data of a pixel having a luminance equal to the previous maximum luminance is held in the data flip-flop circuit 15B.

When the scanning of the processing area, which is the measurement target area set in advance on the screen, is completed, one input of the averaging circuit 21 receives the following information:
The earliest scanned pixel address (X _f , Y _f ) of the maximum brightness pixels is input as the output 19 of the data flip-flop circuit 15A, and the other input is inputted to the scanned earliest pixel address (X f , Y f ) of the pixels with the highest brightness. Since the slowest pixel address (X _l , Y _l ) is input as the output 20 of the data flip-flop circuit 15B, the center address of those pixels ((X _f +X _l )/2,
(Y _f +Y _l )/2) is input to the data flip-flop circuit 15C. This center address is taken into the data flip-flop circuit 15C by the processing area completion pulse 22 generated when scanning within the processing area is completed, and is output as peak point address data 11A representing the center of the peak point. become.

The above description has been made regarding the case where there are a plurality of maximum brightness pixels. As is clear from the above explanation, when there is a single maximum brightness pixel, the pixel address of this maximum brightness pixel is held in both outputs of the data flip-flop circuits 15A and 15B, and the pixel address of the maximum brightness pixel is held in the output of the averaging circuit 21. The pixel address of the maximum brightness pixel is output as is as the peak point position.

Further, FIG. 2 is a diagram showing an embodiment of another invention of the present invention, in which 8, 9, and 10 are the same as the above conventional device, 23 is a threshold value determination circuit, 24 is threshold value data, and 25 is a diagram showing an embodiment of another invention of the present invention. 26 is a binarization circuit, 26 is a binarization video, and 27 is a centroid calculation circuit.

In the peak point detection circuit 10, similar to conventional devices, peak level data 11B in the previous frame is measured and held, and this is taken into the threshold value determination circuit 23, and a value multiplied by a constant (<1), for example, is obtained. This is now given to the field as threshold data 24. The binarization circuit 25 binarizes the image within the processing area using this threshold data 24,
A binarized video in which only the fluorescent image is binary detected is output. Significant pixel a _i (i=1,
2,...N, N is the number of significant pixels), let a _i (X _i , Y _i ) be the pixel address, then the center of gravity calculation circuit 2
7 uses the binarized video 26 and pixel address data 9 to execute the centroid point calculation shown in equation (1) and output the centroid point address (X _c , Y _c ) as peak point address data 11A. Become.

_{X c = N 〓X i} ⁱ ₌ ¹ _{_} Our simple configuration, which only detects the final scan pixel address together, allows us to detect the center of the saturated region even when the fluorescent image is saturated across multiple pixels, which improves the detection accuracy of the device. It can significantly contribute to improvement. In another aspect of this invention, the center of gravity of the reflected light image is determined.
It has the advantage of not being easily affected by noise, and can detect the illuminated spot with high accuracy, making it possible to significantly contribute to improving the reliability of the device.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing one embodiment of the present invention, Fig. 2 is a diagram showing another embodiment of the invention, Fig. 3 is a diagram showing the configuration of a conventional device, and Fig. 4 is a peak point detection circuit. FIG. 5 is a diagram illustrating an example of an imaging frame when a reflected light image is captured over a plurality of pixels in a saturated manner. In the figure, 12, 15A, 15B, 15C are data flip-flop circuits, 13A, 13B are comparators, 21 is an averaging circuit, 23 is a threshold value determination circuit, 25 is a binarization circuit, and 27 is a centroid calculation circuit. be. It should be noted that the same or corresponding parts in the figures are designated by the same reference numerals.

Claims (1)

[Claims] 1. The pixel having the maximum signal intensity of one field picture is the maximum brightness pixel, and the pixel address is the pixel coordinate in the in-screen orthogonal coordinate system in which the pixel pitch is the unit, and there are multiple maximum brightness pixels. In this case, the first storage means stores the pixel address (X _f , Y _f ) with the earliest scanning time among the plurality of maximum brightness pixels, and the pixel address (X ₁ , Y ₁ );
Means for _calculating the arithmetic mean address ( ₍ X _{f +}
This maximum brightness pixel address (X, Y) is
and a means for storing in a second storage means. 2. Means for measuring the maximum brightness level, with the pixel having the maximum signal intensity of one field picture as the maximum brightness pixel, and the pixel coordinates in the in-screen orthogonal coordinate system in which the pixel pitch is the unit, as the pixel address, and K<
means for setting a value K times the maximum brightness level as a threshold using a constant K equal to 1; means for A/D converting a video signal output from an image sensor to obtain video data; Calculate the centroid address (X _c , Y _c ) of the binarized image using means for binarizing data, the binarized image obtained by the binarization, and the pixel address of the binarized image. 1. A fluorescent spot detection device characterized by comprising: means.