JPS6034317B2 - TV image analog correlation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a television image analog correlation apparatus that obtains a horizontal scanning direction autocorrelation image of a television image in real time.

Conventionally, image correlation devices input images from a television camera and perform correlation calculation processing. There are devices that display only horizontal scanning direction autocorrelation images, but such image correlation devices have the following drawbacks in terms of performance and operation.

m Since only correlated images can be displayed on the receiver screen, it is difficult to compare and examine input and output images.

Therefore, a receiver dedicated to displaying the input image is required, and
These two image receivers dedicated to input and output images must have the same screen size and performance. {21 Since finite interval correlation calculations are repeatedly and continuously performed, in terms of the operating principle, the left and right quarters of the correlation image display receiver screen, that is, the screens corresponding to half of the entire screen are not used for display.

Since the finite interval correlation calculation is performed repeatedly and continuously, due to the operating principle, the length of the input image in the horizontal scanning direction must be less than 1/sa of the horizontal synchronization time after being converted to a binary pulse video signal. Furthermore, due to the structure of the optical correlator, there is a condition that the binary pulse video signal must not exist in a range of 1/4 synchronization time before and after the horizontal synchronization pulse.

For this reason, restrictions are placed on the size, composition, and background of an image when capturing an input image. '4} Square value correlation calculation, which is the basic operation of an optical correlator [C(7) = no {f(x one)}
Signal f(x) at 2 {g(x+7)}2dx],
Restricting g(x) to a binary signal, in other words, limiting it to a binary signal of [0, 1]. Therefore, since Pi = 0, 12 = 1, F = f, Z = g, and {f (x one piece)}2 to f(x-
↑) and considering {g(x17)}2 as g(x+7),
Since the normal correlation calculation [C(7)='f(x one block) g(x ten blocks)] is realized, an analog video signal cannot be used as an input signal.

The author and others attended a previous academic conference (IEICE Transactions, 1979, 3rd edition).
Month Vol. 62-A ground. 3 "One configuration method of an image correlation device using an ultrasonic light modulator and a TV camera"), that is, the configuration and operating principle of a conventional image correlation device will be described below. FIG. 4 shows a schematic diagram of the configuration of a conventional device. The outline of the purpose of creating this device was to focus on the fact that the video output signal of a commonly used television camera has a repetition period and frequency band appropriate for the input signal to an ultrasonic optical modulator. The one-dimensional autocorrelation function of the video output signal for each horizontal scan is detected by an optical correlator having a The goal is to obtain correlated images. In the apparatus shown in FIG.
On July 2, 2017, a video camera 14 was used to perform two-way horizontal scanning using triangular waves. Add this. Since the video signal separated here satisfies the conditions for optical correlation calculation described later, it is sent to the video signal pulsing circuit 9 and is compared with a set threshold value to determine whether it is black or white.
It is converted into a binary pulse video signal that represents only values. This binary pulse video signal is applied as an external modulation signal to a pair of sine wave oscillators la and lb which are capable of pulse amplitude modulation.
The sine wave oscillators la and lb oscillate at the resonant frequency of the ultrasonic transducers constituting a pair of ultrasonic light modulators 5a and 5b arranged in the optical correlator, and the oscillated waves are generated by the oscillator. The signal is amplitude-modulated by the two types of pulse image signals and applied to the ultrasonic light modulators 5a and 5b. The optical correlator is constructed as follows. A Caesar 4 is used as a light source, and after the light is magnified by a lens, it enters the ultrasonic light modulators 5a and 5b. The pair of ultrasonic light modulators are arranged so that the ultrasonic waves travel in opposite directions, and the speed of light that passes through them is converged by a lens to create a bright spot on the focal plane. A spatial light intensity filter 6 is arranged on the focal V point plane, and the light passing through this filter is photoelectrically converted by a photoelectric converter 7 to become an output current of an optical correlator. Note that the principle of optical correlation calculation will be explained in detail later. The synchronizing pulses separated by the synchronizing pulse separation circuit 10' are sent to a horizontal synchronization time delay circuit 11, subjected to a time delay, and then added to a mixer 12. This mixer 12 adds a delayed synchronization pulse to the correlation output signal obtained by the photoelectric converter 7 to create a composite video signal to be a correlation image. If the delay time of the horizontal synchronization time delay circuit 11 is set to approximately 1/2, 32rs of the horizontal synchronization time, and the composite video signal is formed into an image by the receiver 16, the autocorrelation image of the input image 13 can be displayed on the screen. It can be displayed in the center. Next, the principle of optical correlation calculation will be described. The image signals obtained by bidirectional horizontal scanning, the scanning direction of which is reversed for each scan, are spatially inverted, delayed, and shifted by two ultrasonic optical modulators, and then integrated by a lens to produce images that are adjacent to each other, i.e., the screen. In the above example, the cross-correlation function between video signals in a vertical relationship is roughly obtained by approximating the auto-correlation function. As shown in FIG. 5, the input image is a binary image P(Q, 3), and the video signal f(Q, n) obtained by the n-th horizontal scan from the vertical synchronizing pulse is assumed. As shown in Figure 6, 2
The ultrasound signal shaped into a value pulse video signal and amplitude modulated by f(Q,n) is applied to an ultrasound transducer in an ultrasound light modulator. Since the ultrasonic light modulators 5a and 5b are arranged so that the directions of ultrasonic propagation are opposite to each other, the ultrasonic signals in the ultrasonic light modulators are u(x, n), u(1×
, n). The ultrasonic light modulator 5a is made to have a longer length in the ultrasonic traveling direction than the ultrasonic light modulator 5b, and the ultrasonic light modulator 5a
The time for (x, n) to reach the laser beam is u(1×,
n) is delayed by one horizontal scanning time of 63.5 seconds from the same time. Therefore, the ultrasonic signals that overlap within the laser beam are u(x, n) and u(1×, n11). The superposition of two signals within the optical system is expressed by a product operation, and the convergence effect of the laser is expressed by an integral operation. Also, u(x, n), u(
1×, n+1) is moving at an ultrasonic velocity v, we can generate an electric current by photoelectrically converting only the diffracted light generated by the ultrasonic signal detected by the spatial light intensity filter 6. It is known that the following correlation output c(t,i) can be obtained as a value. Here, d represents the width of Caesar Koto. g(x,n) represents the hull vertical line of u(x,n), and is obtained by linearly converting Q of f(Q,n) to x.

In this {1} formula, g(X, i) main g(1×, j+1)...
Applying the relationship [2-], c(t, i) represents the autocorrelation function of g x,i, that is, f(Q, i).

Both c(t, n) and f(Q, n) are functions of the number of horizontal scans n. Therefore, c(t,n) becomes f(Q,n
), the horizontal scanning direction autocorrelation function of the input binary image is obtained. However, as a condition to obtain independent c(t, n) for each n by executing equation 3', there must be a no-signal part of the same length before and after the video signal, so The maximum length of the signal is limited to 1/2 of the horizontal synchronization time. Further, when the above equation '1) is executed by an optical correlator, the square value correlation calculation shown in the following equation is actually performed due to the square characteristic during photoelectric conversion in the photoelectric converter 7. '4} expression and '31
In order to make the expressions equivalent, we limit g(x) to a binary function of [10] and write {g(x-vt,i)}2=g(x-vt,i
) “Use the relationship ``.

Specifically, it is necessary to limit the input image to a black-and-white binary image as in the conventional apparatus, or to provide a circuit for converting the video signal into a binary value based on a set threshold value. The above is the configuration and operating principle of the conventional device.

Since the purpose of the conventional device is to recognize patterns of simple figures or letters and symbols, various limitations arising from the above-mentioned operating principle are overcome by limiting the operation of the device. In other words, the generation of no-signal parts is done by fixing the TV camera and placing the input image with a limited horizontal length on a black and white background, and the binarization of the video signal is done by converting the input screen itself into a black and white binary image. I am doing it. In addition, there are problems in the performance and operation aspects of the conventional device as listed above. The present invention aims to compensate for the drawbacks of the image correlation device described above, and to make the device more practical and functional by adding new devices.

That is, it is an object of the present invention to provide a television image analog correlation device that removes restrictions on the size of input images and can input all analog images including moving images that can be input with a television camera.

Furthermore, it is characterized by simultaneously displaying the input image and the correlated image on the left and right sides of the center of the receiver screen for simultaneous comparison of input and output images. To achieve this purpose, we newly added an analog circuit that square-compresses the video signal applied to the correlator, such as a signal compression circuit that uses the nonlinear voltage-current characteristics of a diode that is commonly available on the market. In order to form a no-signal portion in the video signal regardless of size or movement, a light intensity filter (also referred to as an optical filter) is placed on the light incident surface of the image pickup tube inside the television camera.

Furthermore, a single horizontal scanning image is extracted from the bidirectional horizontal scanning image.

A horizontal synchronization selection selection circuit was added. Next, the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of a television image analog correlation apparatus for displaying an autocorrelation image in a horizontal scanning direction according to the present invention.

In this apparatus, an autocorrelation calculation is performed using an analog video signal, and the correlation calculation operation in the correlator 101 is similar to the operating principle of the conventional apparatus. The configuration and operating principle of FIG. 1 will be explained as follows while comparing it with FIG. 4, which describes the configuration of a conventional device. In the present invention, the optical system portion (FIG. 1A) of the television camera 14 used as a follower device is an enlarged view of the portion A. A light intensity filter (optical filter) 22 as shown in FIG. 2 was arranged. FIG. 2 shows that a light intensity filter (optical filter) 22 is arranged between the television camera lens system 21 and the image pickup tube 23. FIG. 3 shows the shape of this light intensity filter 22 when viewed from all directions of the optical axis of the lens system 21 of the television camera.
In FIG. 3, the rectangle in the center of the figure is an open circle through which light enters. The short side of this opening coincides with the horizontal scanning direction of the imaging tube 23, and the width of the opening is determined to be 1/Z horizontal scanning length of the imaging tube 23. Further, this light intensity filter 22 is arranged at the center of the light entrance window of the image pickup tube 23. Next, in the present invention, the video signal pulsing circuit 9, which is a component of the conventional device, is removed, a compression circuit 17 for compressing the video signal is newly added, and a horizontal synchronization selection circuit 2 is added. There is. The function of this horizontal synchronization selection circuit 2 is to sample the video signal of the input image obtained by bidirectional horizontal scanning using an analog gate circuit that operates in synchronization with the horizontal synchronization pulse.
It extracts only the video signal obtained by horizontal scanning in a single direction, which allows the input image to be displayed on the receiver without correlation processing, avoiding the duplication of reversed images due to bidirectional horizontal scanning. . In addition, the delay time of the horizontal synchronization time delay circuit 11 is 1/Z used in the conventional device.
Changed from 32 ms Tue flat synchronized time, 1' evening k flat synchronized time 1
It was set to 6rs. FIG. 7 shows that based on these results, the input image and the correlated image can be displayed on the screen of the image receptor 16 with the center as the border. Fig. 7a shows a video signal obtained by bidirectional horizontal scanning of an image to be autocorrelated, and Fig. 7b,
c represents the ultrasonic signal in the ultrasonic modulators 5a and 5b already described. Figure d shows the output of the mixer 12. Inside the ultrasonic light modulator 5a in d of the same figure, the ultrasonic signal is
Since it requires a delay of 3.5 peaks and 32ms to overlap with the internal ultrasonic signal of the ultrasonic optical modulator 5b, the center of the correlation output appears at the same time as the horizontal synchronizing pulse, as shown in d of the figure. Therefore, if the sweep width of the video signal is set to 1/Z horizontal scanning length by the light intensity filter 22 of the television camera 14, the video signal and the correlation signal will not overlap in time. Therefore, as shown in the figure, the horizontal synchronization pulse is 1/t
By delaying the fire level synchronization time by 16 seconds, it becomes possible to display the input image and its correlated image on the left and right sides of the center of the image receptor screen. Further, the video signal f(Q, n) is square compressed by the compression circuit 17, and the video signal f(x, n) is
and is added to the correlator 101.

Therefore, the square value correlation calculation shown in the above equation [4} is as follows. Therefore, there is no need to limit the video signal to a binary signal, and correlation calculation using an analog video signal becomes possible.

The present invention has the above-described configuration, and has the effect that, as long as the image can be photographed by the television camera 14, the horizontal scanning direction autocorrelation image of the image can be simultaneously compared and observed on the same picture tube as the input image.

Further, since correlation processing of analog images is possible and there are no restrictions on the size of the input image or the position of the captured image, it is also possible to photograph and input moving objects. In this case, it is also possible to record the results of long-time photography with the television camera 14 fixed on a video tape or the like, and use the video signal as an input signal for the device, or to use the correlation result as a key image. Effects such as time-lapse photography and high-speed photography within the operating speed of the television system can also be expected. Furthermore, the input image can be enlarged or reduced by replacing the lens system of the television camera 14, which is effective for more accurate measurements.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the internal structure of the section A in FIG.
2, FIG. 4 is a diagram showing a conventional example, FIG. 5 is a diagram showing bidirectional horizontal scanning of an image, FIG. 6 is a diagram showing a signal timing chart, and FIG. 7 is a diagram showing a signal timing chart. Figure shown. la, lb are sine wave oscillators, 2 is a selection circuit, 3a, 3b
is a broadband amplifier, 4 is a Caesar, 5a and 5b are ultrasonic light modulators, 6 is a spatial light intensity filter, 7 is a photoelectric converter,
8 is a video signal amplifier, 9 is a video signal pulsing circuit, 1-stream synchronization pulse separation circuit, 11 is a horizontal synchronization time delay circuit, 12 is a mixer, 13 is an input image, 14 is a television camera, I5 is both 16 is an image receiver, 17 is a compression circuit, 18 to 2 are missing numbers, 21 is a television camera lens system, 22 is a light intensity filter (optical filter), 23
100 is an imaging tube, 101 is a correlator, 102
indicates the Fourier transform optical system, and A indicates the position where the light intensity filter is located. ULM5a and ULM5b are ultrasonic light modulators, and f(Q,i) and f(Q,i+1) indicate input image signals. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. An image correlation device for displaying an input image and an autocorrelation image of the input image to the left and right with the center of the same screen of an image receiver serving as a border, comprising: a lens system 21 and an image pickup tube 23; an imaging device 100 that outputs a composite video signal obtained by bidirectionally horizontally scanning the input image; an optical filter 22 having an aperture width limited to: a separation circuit 10 for separating the composite video signal into a video signal and a synchronization signal; a compression circuit 17 for square-compressing the separated video signal; a correlator 101 that receives a compressed video signal output from the circuit and outputs an autocorrelation signal; output from the separation circuit to display the autocorrelation image on either the left or right half of the screen of the receiver; a delay circuit 11 for delaying the synchronization signal; and a selection circuit 2 for selecting only the signal obtained by one-way scanning of the horizontal scanning by the delayed synchronization signal from among the separated video signals. and; receiving and mixing the separated video signal output from the selection circuit, the autocorrelation signal output from the correlator, and the synchronization signal output from the delay circuit;
A television image analog correlation device comprising: a mixer 12 which supplies the mixed output to a television receiver. 2. The correlator 101 includes a pair of amplitude modulated sine wave oscillators 1a and 1b; broadband amplifiers 3a and 3b which take the output signal of the sine wave oscillator as an input signal; and ultrasonic wave using the output signal of the amplifier as an input signal. a Fourier transform optical system 102 having a pair of ultrasonic light modulators 5a and 5b whose propagation directions are opposite to each other; a laser 4 that is a light source of the optical system; and a photodetection filter that detects the output light of the optical system. 6; and a photoelectric converter 7 for photoelectrically converting the output light.