JPS5928606A - Detection of moving body - Google Patents

Abstract

PURPOSE:To eliminate the influence of the image moving in the direction differing from the direction where photodetector groups are arranged by disposing the plural photodetector groups in the difference positions on an image plane and combining the same. CONSTITUTION:Photodetector group X-1, Y-1, Z-1 are disposed at the center and corners of an image plane 2. The group X-1 are juxtaposed with photodetectors 6-10 at specified intervals (l), and measures dividedly the light of a part of an object image. The outputs A'-E' at the time t0 for starting measurement are stored in a storage circuit 11 and the outputs A-E after t1 are fed to an arithmetic circuit 12 for the output difference between the same photodetectors, an arithmetic circuit 13 for the output difference between the photodetectors shifted by one piece in a right direction and an arithmetic circuit 14 for the output difference between the photodetectors shifted by one piece in a left direction. The same holds true of the groups X-1, Z-1. The outputs of absolute value circuits 15- are fed to an adder 32, and average value circuits 38-. The outputs I , II, III are compared in a min. comparator 38, by which the movement and pause or moving direction of the image are known.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the movement of an image, which is used in optical equipment such as photo cameras, television cameras, and cine cameras. It concerns the method of measurement.

In general, there are two types of image blur in photography: one is due to the movement of the subject, and the other is due to movement of the camera itself.
In either case, the position of the image of the subject σ) that appears on the screen changes. The latter type of image blur caused by the movement of the camera itself is caused by the camera being mounted on a moving object such as a car or airplane (1a), and the other is caused by camera shake, which is caused by the movement of the camera itself. There are some things that happen.

If the camera or subject moves continuously and the speed of movement at the time of shooting can be predicted, the shutter speed should be set according to the speed of movement of the image, or if the shutter speed is inappropriate. Image blurring can be prevented by displaying a first-class notification, or by detecting the moving speed and direction of the image and moving the photographic lens to display it as a still image. In addition, if you measure the speed of the image while the shutter is open and calculate and display the shutter speed necessary to remove image blur from this, you can compare this value with the actual speed of the photographic film. It is possible to check whether the image recorded on the camera was shot at the time of shooting. Therefore, in order to prevent image blur, it is necessary to accurately know the moving speed (shake speed) of the image or the camera itself. .

In order to detect the moving speed of this image, the present applicant proposed a ``Moving Object Detection Method'' Japanese Patent Application No. 1973 G-15255.

This method uses a group of photodetectors arranged at regular intervals to measure an image of a subject at a desired time, stores the output of each photodetector, and then The images are measured over time, and the average value of the absolute value of the difference in the output of the same light receiving element at two different times is added, and the image is adjusted by shifting at least ili in one direction. The average value of the sum of the absolute values of the differences in output between the light-receiving elements at two different times is calculated, and when the average value of the V person is smaller than the former average value, It is determined that the image has moved by 1/2 of the distance between the light-receiving elements 1, and the time until this image movement is detected is measured 7 to determine the moving speed of the image.

If the spatial frequency of the image is tilted with respect to the direction in which the light receiving elements are arranged, erroneous detection may occur. 1st
The figure shows this state, in which a light-receiving element group 1 consisting of five light-receiving elements is arranged at the center of the screen 2. An image 8 in the form of a black and white pattern is formed on this light-receiving element group 1 and is moving in the direction of the arrow 4. In the case of such an image, even if the light receiving element group 1 moves in a direction different from the array direction, it will be mistakenly recognized as moving in the array direction, and the moving speed will be measured incorrectly. SUMMARY OF THE INVENTION An object of the present invention is to provide a moving object detection method that can eliminate the influence of images moving in a direction different from the direction in which the light receiving element group is arranged.

Generally, the directions of spatial frequencies often differ at distant positions on the screen. Therefore, in the present invention, by arranging a plurality of light-receiving element groups at different positions on both surfaces and combining these light-receiving element groups, the influence of the tilted spatial frequency that moves in a direction different from the arrangement direction of the light-receiving elements can be eliminated. It's made to cancel out.

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows an example of the arrangement of the light receiving element group.

Light-receiving element groups X-1 and Y-1 are placed on the medium heat and two corners of screen 2.
Z-1 is placed. Note that the light receiving element groups may also be arranged at the upper right and lower left.

FIG. 3 illustrates the principle of the invention. Photodetector group X
-Ltd:, for example, 5 light receiving elements 6, 7°8.9.1
0, which are arranged in parallel rows with a constant interval l. This light receiving element group 1 includes a potdiode,
A phototransistor, a Cd8 element, a CCD element, etc. are used, and part of the subject image is metered separately. 1. At the start of measurement 2o), the outputs A', B', C' of each light receiving element 6 to 10 are
, D', and E' are stored in the storage circuit 11. Each of the light receiving elements 6 to 1 at the time 1° stored in this memory circuit 11
The outputs A'-E' of O and the outputs A-E of each light-receiving element 6-100 obtained by measuring after 1 second are connected to the arithmetic circuit 12. Rightward which calculates the difference in output between the same light-receiving elements. An arithmetic circuit 18 calculates the difference in output between the light receiving elements shifted one by one to the left.The signal is sent to an arithmetic circuit 14 which calculates the difference in output between the light receiving elements shifted one by one to the left. The results of the operations a of circuits 12 to 14 are sent to absolute value circuits 15 to 17, respectively, which calculate absolute values.

Similarly, a memory circuit 1 that stores the output of the light receiving element group Y-1
8. Operator η circuits 19 to 21° absolute value circuit 22 for calculating the difference
~24 are provided. Also for the light receiving element group Z-1, the memory circuit 25. η calculation circuits 26, =-, 28, and absolute value circuits 29-81 are provided.

Said approximately 7+ value circuit t 5 , 22 , 29 output iJ
/l1lJ'? After being added in the circuit 82, the signals are sent to the average value circuit 38, where they are divided by the number of combinations, and a signal [I] representing the average value is calculated. The outputs of the absolute value circuits 16 and 28.degree. 80 are also added together in an adder circuit 84, and then an average value is calculated in an average value circuit 85. Similarly, absolute value circuit 17
, 24.81 are also added by the adding circuit 86 and then sent to the average value circuit 87.

The reason for converting to the average value is that the number of arithmetic elements is different, but this can be done by inserting a dummy signal and matching the numbers, as shown in FIG.
87 can be omitted.

The output m of the average value circuit 8B, 85.87 shown in FIG.
The old and [■] are compared by the minimum comparator circuit 88 and the output (1
) is the minimum value, the subject image is stationary (or the subject is moving very slowly), and the output is When (III) is the minimum value, the movement is l/2 to the left. This makes it possible to know whether the image is moving, stationary, or if it is moving, the direction in which the image is moving.

L11 indicating that the image remains still to check the moving speed of the image
IJJ force (II), which indicates the movement of an image, is better than 1 force [I].
, (III) is the minimum value. 1. Since this time t2 is the time required to move approximately 1/2 of the distance between the light receiving elements in the light receiving element array, It is proportional to the moving speed, so the moving speed of the image can be determined.

When the light-receiving element groups are arranged in a line, when the image moves in a direction perpendicular to this, it cannot be detected. To prevent this, it is desirable to arrange two groups of light receiving elements so as to be perpendicular to each other, as shown in FIG. In this case, the light-receiving element at point Da is used for two light-receiving element groups. These 2 arranged to intersect
The light-receiving element groups are arranged at desired positions f~ on the screen 2 shown in FIG.
will be placed in Also, if the image moves diagonally, rotate it and
Considering the case where the light receiving element is used, it is desirable to arrange the light receiving element groups vertically, horizontally, and diagonally radially at regular intervals 4 as shown in FIG.

Next, a case where the present invention is applied to a photographic camera will be described. In general, based on the physiological rule of thumb that the human eye cannot distinguish between individual objects at a viewing angle narrower than 50 to 90 seconds (in angular units), even if the distance of image movement on photographic film is less than 40 microns, If so, it is thought that the problem of blurring will not occur. The relationship between the moving speed of the image and the shutter speed when the distance is 40 μ is shown in Table 1.

Table 1 and FIG. 7 show a schematic diagram of the camera. Subject light passing through the photographing lens 40 is incident on the photographic film 41.

On the other hand, the subject light passing through the lens 42 enters the photometry section 43. The angle of view of this lens 42 is approximately the same as the shooting angle of view. Each light receiving element group X, Y, Zl-J is composed of four light receiving element groups arranged radially as shown in FIG. As shown in FIG. 2, eight sets Nf are arranged diagonally on the screen 2.

In front of each set XXYXZO is a small lens 44.45°46
are provided respectively, and when combined with the lens 42, a telescope system is created. As shown in Table 1, the slowest moving speed that is equivalent to a still image is 1.2μ/+ns,
If the 4-measurement time is 10 ms, the image moves on the screen by 12 μ within this time. Lens 42 and Lens 44.4
5.46, the movement of this image can be facilitated by setting the distance l between the light receiving elements to 120μ as shown in FIG.

If there is no need to detect internal scratches and only camera shake is detected, the light receiving Yonago y! It is also possible to provide the light receiving element UY near the outside of the photographic film surface as shown in FIG. 8 without providing the optical system Y. FIG. 9 shows an embodiment in which the present invention is utilized for exposure control. Twelve photodetector groups are used, of which X-
, 1, Y-1, and Z-1 are combined to constitute a photometric section of one detector as shown in FIG. Similarly, X-2
, Y-2, Z-2 are combined, and X-8, Y-8, Z
-3 is a combination, and X-4, Y-4, and Z-4 are each combined. Here, the numbers represent the arrangement direction of the optical element group arranged as shown in FIG.

When the release button is pressed, the reset circuit 50 is activated! -2, the counter 52 that counts the clock signal of the oscillator 51 is reset. At the same time, the tte storage circuits 54a to 54d of the calculation units 58a to 58d store the outputs of the respective light receiving element groups X-1 to Z-4. As explained in FIG. 8, the calculation units 53a to 58d When movement of the image is detected during measurement, a pulse is output.If a pulse is output from any one of the calculation units 53a to 58d, the output of the circuit 55 or 56 becomes ``11'', causing a problem or prohibition. Since the gate 57 becomes "1", the contents of the counter 52 are latched by the latch circuit 58. The output of the output circuit 56 is sent to a delay circuit 59, where it is delayed for a certain period of time, and after the latch is completed, it is sent to the memory circuits 54a to 54a.
54d and counter 52 to reset them and start measurement again. As a result, the latch circuit 58
The latest image movement will always be recorded.

The signal for detecting the faj still image is below a certain value,
And if this is the minimum value, V''1, calculation units 58a to 5
There is no pulse from 8d. That is, since the image is in this state even if the image is moving at lo at the start of measurement, if a pulse is generated at this time, it will cause malfunction. When opening an image with very slow movement, the calculation unit 533 is
Since no pulse is output from any of the pulses 58d to 58d, the counter 52 counts up to the briset value. The coincidence circuit 6° detects that the counter 52 has reached the pre-seventh value and sends a pulse to the OR circuit 56. As a result, even if it is a still image, the moving speed of the image is the slowest1,2
It is equated to tt/m s, and the contents of the counter 52 are latched into the latch circuit 58. By resetting the device at regular intervals in this manner, errors can be reduced even when the image movement speed changes rapidly over time. When the shutter is released, inhibit gate 57 prevents transfer of the contents of latch circuit 58. The exposure n0 circuit 61 determines the shutter speed according to the time required to move to a certain distance l stored in the latch circuit 58. This shutter speed is calculated together with a signal from a brightness measurement circuit 62 that measures the brightness of the subject to determine the aperture. When shooting with priority given to shutter speed, the camera compares the shutter speed determined from the image movement speed with the set shutter speed and displays a warning to see if blurring occurs.

FIG. 10 shows an example of the minimum comparison circuit. Diodes 71, 72 and resistor 73 take out the smaller of the signal (Ill'1 and signal (II)) and connect it to comparator 7.
Send to 4. On the other hand, the signal (1) is transmitted through the diode 75. After being inverted by a resistor 76, it is sent to a comparator 74, where it is compared with the smallest of the signals CII) and (III). During this comparison, if the signal []■] becomes larger, the output [L] of the comparator 74 changes to “-11
”. When the output of the comparator 74 is inverted, a rising edge detection circuit 77 outputs a Kagura pulse.

The minimum value d4 of signal (1), I [1, f,
Judgment is based on 3. 7. Only when this value is smaller than the reference value, the gate 84 is opened and the pulse from the rising edge detection circuit 77 is passed through. As shown in Figure 11, this is done so that pulses are not emitted when the moving direction of the image is perpendicular as shown in C and 2 in the figure, or rotated as shown in Po, and parallel as shown in A and Mouth. This is to enable pulses to be emitted when only in the direction. Also, if the brightness of the object changes drastically and the image jerks or jerks, the output is stopped accordingly. 1, the incoming signals from each detector are collected by the zero circuit 85, and if all are abnormal, that is, the output of the zero circuit 85 becomes rLJ, a falling detection circuit 86 outputs a pulse, and the zero circuit 85 outputs a pulse. 55 and perform the measurement again.

In the embodiment described above, the difference in output between adjacent light receiving elements is calculated, but the difference in output between light receiving elements shifted by two may also be used. In this case, the moving distance of the image is l. Furthermore, at the beginning of measurement, the contrast of the image is detected, and if this value is below a certain value, to prevent false detection,
It is desirable to interrupt the measurement of that detector.

The present invention having the above two configurations combines a plurality of light-receiving element groups arranged at different positions on the screen and treats them as if they were one light-receiving element group. It is more likely to be affected by tilted spatial frequencies moving in different directions, allowing more accurate measurements to be made.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a spatial frequency moving in a direction different from the arrangement direction of the light receiving element group. FIG. 2 is an explanatory diagram showing an example of rearranging the light receiving element group. FIG. 8 is an explanatory diagram 2 showing the principle of the present invention, and FIG. 4 is an explanatory diagram tjl'1 showing an embodiment in which the average value circuit is omitted. FIGS. 5 and 6 are explanatory diagrams showing an embodiment in which lights are arranged so as to directly connect a group of light receiving elements. FIGS. 7 and 8 are explanatory diagrams showing an embodiment in which a group of receivers>r:';p children is arranged in a photographic camera. FIG. 9 is a block diagram showing an embodiment in which the present invention is utilized for exposure control of a photographic camera. FIG. 1O is a block diagram showing an example of a minimum comparator circuit. FIG. 11 is an explanatory diagram showing the moving direction of the image. l... Light receiving element group 2 ・ ・ ・ 1 curved surface X-1, 'r-1, Z-1... Receiving 9'C element? ll7
1 J, 18.25...Storage circuit 12-14.19-21.26-28...Arithmetic circuit 1
5~17.22~24.29~31...Absolute 1111
Circuit 83 84.86...Addition circuit 8B, 85.87...Average value circuit 40...Photographing lens 48...Measuring units 44-46...Lens. Figure 4 Procedural amendment (method) Shohaku + 5 ft December 8th Mr. Commissioner of the Japan Patent Office 1 Indication of the case 1982 Patent B No. 189442 3 Person making the amendment Relationship with the case Patent applicant 11 Place Minamiashigara, Kanagawa Prefecture 210 Nakanuma, City Name
(5207 Hatashi Photo Film Co., Ltd. 4, Agent (2) All drawings 8, Contents of supplementary IF

Claims (1)

[Claims] Using multiple groups of light-receiving elements arranged at regular intervals, these groups of light-receiving elements are placed at different positions on the screen, and each part of the image is measured at an arbitrary reference time. The output of each light-receiving element is memorized, and after this memorization, a part of the image is continuously measured.
The absolute value of the difference in the output of the same light-receiving element between the reference time and the current two different times, and the absolute value of the difference in the output between two light-receiving elements combined by shifting at least one light-receiving element in one direction. Determined for each light receiving element group, each light receiving element group 4
e, at least 2f! After adding the absolute values of the IL classes, calculate the average value, and when the average value between different elements becomes smaller than the average value between the same elements, the image moves a certain distance. A moving object detection method characterized by determining that.