JPH09288060A - Method and apparatus for capturing moving body image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly decide the image adapted to image analysis from images by a simple method when the images are captured by imaging moving bodies sequentially fed at a predetermined interval. SOLUTION: The method for capturing moving body image comprises the steps of imaging the bodies by an imaging camera 4 at a predetermined time interval, storing present image data in a first memory 61, and storing the image before one in a second memory 62. The method further comprises the steps of fetching the representative range of the image data by a sampling unit 71 as one-dimensional image, converging it into one-dimensional binary image by a binarizer 72, checking whether one body is completely input to a screen or not by an effective visual field deciding unit 73, and calculating the deviation of the center of the body from the input binary image from the center of the screen by a central deviation calculator 74. The best image deciding unit 75 decides the continuation of using either the image stored in the first memory or the image stored in the second memory based on the deviation or capturing the image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for capturing an image of a moving body, which selects an image of an object continuously moving on a belt conveyor or the like from image data taken at regular intervals to obtain the best image. And equipment.

[0002]

2. Description of the Related Art In some cases, objects moving one after another on a belt conveyor or the like, such as melons, are imaged one by one, and are graded by image analysis. FIG. 11 is a diagram showing a conventional moving body imaging apparatus. 1
0 is an object to be imaged, and the belt conveyor 11
Are transported one after another. Reference numeral 1 denotes an arrival detector of the object 10, which is, for example, a photoelectric sensor or the like, and is arranged at a distance L from the imaging camera 4 along the belt conveyor 11. Reference numeral 2 is a transmitter for measuring the moving distance of the belt conveyor 11, that is, the moving distance of the object 10. For example, an incremental encoder is used to generate one pulse per unit moving distance ΔL of the belt conveyor 11. I shall. The number P of pulses generated when the object 10 is moved by the distance L from the arrival detector 1 to the position of the imaging camera 4 is represented by P = L / ΔL.

The width of the object 10, that is, the length in the moving direction is called the width of the object 10, and r is 1/2 of the width of the object 10.
Represents When the object 10 is close to a sphere like a melon, r indicates a radius. This value should be considered in order to define the effective installation distance L between the arrival detector 1 and the imaging camera 4. Reference numeral 5 denotes a trigger generator, which starts counting pulses from the oscillator 2 each time a signal from the arrival detector 1 is received, and opens the shutter for the imaging camera 4 each time the value reaches P described above. Give a command T. At the same time, the image capturing permission signal I is generated to the image analyzer 6 which captures and analyzes the image captured by the image capturing camera 4. This ensures that the video signal V immediately after receiving the signal I is centered in the field of view of the camera. Note that a strobe flash may be used instead of an image pickup camera whose shutter can be opened at an arbitrary time (hereinafter referred to as a random shutter camera).

[0004]

Although the above-mentioned moving body image pickup device has been put into practical use and is operating satisfactorily, it also has the following problems. Arrival detector 1 is required. A transmitter is required to measure the distance traveled by conveyors such as belt conveyors. A trigger generator 5 (delay calculator) for notifying the image pickup camera 4 of the timing of opening the shutter is required. When the size of the object changes, an error occurs in the image capture position. It requires a relatively expensive random shutter camera or strobe illuminator. The layout of the trigger generator becomes complicated in the layout in which a plurality of objects are placed within the physical distance between the arrival detector and the camera.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a moving body image pickup apparatus which is simple and capable of high-speed processing.

[0006]

In order to achieve the above object, according to the invention of claim 1, a moving body moving in front of a fixed image pickup device is imaged at a constant time interval, and the present image data and the previous image data are obtained. Image data of the image data is stored, the amount of deviation between the center coordinates of the moving direction of the moving body and the center of the screen is calculated for both image data, and either image data is used or the image is captured based on this amount of deviation. Decide whether to continue.

A moving moving body is imaged at regular time intervals, that is, at the field of a normal television camera or at a frame rate, the current image and the previous image are stored, and the stored image is displayed at the center of the screen. Discriminate between an effective image in which the entire image of the moving body is shown in the vicinity, and an ineffective image in which a part of the entire image of the moving body is missing near the edge or in which the images of two moving bodies are shown. . The ineffective image is discarded, the amount of deviation between the center coordinate of the moving direction of the moving body of the effective image and the center of the screen is calculated, and either the current image data or the previous image data is calculated based on this amount of deviation. Decide whether to use or continue with image capture. When the best image data is discriminated from the image data itself taken at regular time intervals in this way, the hardware configuration becomes extremely simple.

According to a second aspect of the present invention, a fixed image pickup device for picking up an image of a moving body at fixed time intervals, a sampling section for taking out a representative range of image data picked up by the image pickup device as one-dimensional data, and A binarization unit for binarizing one-dimensional data into a moving body and a back shadow, and
An effective field-of-view determination unit that determines effective image data in which the entire image of the moving object is within the screen for the binarized data, and an image memory that stores the current image data captured by the image capturing apparatus and the previous image data. A center shift calculation unit that calculates a shift amount between the center position of the moving body and the center of the screen of the binarized data determined by the effective visual field determination unit; and based on the shift amount calculated by the center shift calculation unit, The present image data in the image memory and the best image determination unit that determines whether the previous image data is used or whether image capture is continued are provided.

[0009] The image pickup device picks up an image of an object moving forward one after another at regular intervals, and a typical range of the imaged image data, for example, in the case of a sphere, one-dimensional data near the equator,
In other words, the data on the horizontal scanning line is taken out by the sampling unit, and this one-dimensional data is used to represent the background and the object.
Convert to digitized data. The effective visual field determination unit analyzes the binarized data thus obtained, and determines whether or not the entire image of the moving body is the effective image data within the screen. Image data is stored in the image memory and is sequentially stored together with the previous image data. The center shift calculation unit obtains the shift amount between the center of the moving body and the center of the screen for the effective image data determined by the effective visual field determination unit, and uses any image data stored in the memory based on this shift amount. Or leave it to the next and subsequent decisions. As a result, the hardware such as the arrival detector, the transmitter, and the trigger generator used in the conventional device is not required, so that the structure is simple.

In the third aspect of the present invention, the sampling section adds one-dimensional data of a plurality of horizontal scanning lines in a predetermined range in the vertical direction, in other words, calculates averaged one-dimensional data.

The moving direction of the object is the horizontal scanning line direction of the screen, and the length in the moving direction of the object is called the width. If the width of one object completely appears on the screen, effective image data is obtained. Becomes Therefore, a certain range in the vertical direction of the horizontal scanning line near the maximum width is predetermined for the object, and one-dimensional data of this horizontal scanning line is added in the vertical direction of the specified range to obtain the average. The obtained one-dimensional data is obtained. By this addition, the influence of noise can be considerably eliminated.

In the invention of claim 4, the effective visual field determining section assigns level 1 when the binarized data changes from 0 to 1, and when it changes from 1 to 0, level 0
To represent changes in an alternating array of 0s and 1s. The change pattern thus obtained is compared with a standard change pattern created in advance to determine whether or not one moving object is surely included in the screen. In this case, the change from 0 to 1 may be the level of 0, and the change from 1 to 0 may be the level of 1. By doing this, for example, 5
One-dimensional data composed of 12 pixels can be represented by a change pattern of 4 to 5 bits. Such a change pattern is compared with a standard change pattern prepared in advance, and it is determined whether or not one moving object is definitely included in the screen.

According to a fifth aspect of the present invention, the center deviation calculating section calculates an average value of positions at which the binarized data first detects the arrival of the moving body and subsequent positions at which the disappearance of the moving body is detected. It is the center of the binarized data.

When one moving object is certainly included in the screen, for example, in the case of one-dimensional data in which the moving object is 1 and the background is 0, the position of the first rising edge and the subsequent falling edge are on the screen. The position of the moving body above is shown. Therefore, the average value of the rising and falling positions represents the center position of the moving body on the screen. In the case of one-dimensional data in which the moving body is represented by 0 and the background is represented by 1, the average value of the positions of the first falling and the subsequent rising is the center position on the screen of the moving body.

According to a sixth aspect of the present invention, the image memory is composed of a first memory and a second memory, and image data of a changed screen is alternately stored in the first memory and the second memory each time the screen changes. , The best image determination unit issues a first command to select the current image data and the image data of the previous screen.
The first selection command represented as the current image data is fixedly stored in the memory and the previous image data is fixedly stored in the second memory is inverted by the first selection command in synchronization with the screen change. 2 Change to a selection command and output.

The invention of this claim is one means for storing the current image and the previous image at a higher speed by hardware. When the image data of the current screen is stored in the first memory and the image data of the previous screen is stored in the second memory, a command for selecting the current image data and the image data of the previous screen is issued. The place to put out may be fixed. However, the contents of the first memory must be moved to the second memory each time new current image data arrives. Therefore, the current image data is alternately stored in the first memory and the second memory each time the screen (frame) changes, and the selection command also changes its polarity each time the screen changes, for example, if the first memory is selected. If the second memory is selected, the second memory is output instead of the first memory. This eliminates the need to transfer data from the first memory to the second memory, which simplifies the device and speeds up the process.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of the first embodiment. The present embodiment is a device that takes in the best image data of the image data of each object 10 captured by the image analyzer 6 while the object 10 is moving on the belt conveyor 11 one after another. The object 10 is, for example, a melon, and the image analyzer 6 is a device that analyzes a mesh image on the surface of the melon and determines a grade and the like. In the present embodiment, only the process of capturing the best image data to be the basis of analysis will be described, and the subsequent analysis processing will not be described. The image pickup camera 4 is a camera that outputs a video signal, and uses a so-called normal shutter camera in which a shutter operates at a constant cycle generated by itself. The image analyzer 6 has two memories for capturing image data, a first memory and a second memory, and the image data V captured by the imaging camera 4 in a constant cycle is overwritten in the first memory one after another and at the same time originally. The image data in the first memory is transferred to the second memory. As a result, the current image data is stored in the first memory, and the previous image data is stored in the second memory. The image data of the image pickup camera 4 is also sent to the best image determination device 7, and the current image data or the previous image data of the image in the effective field of view is the best image data, or the still best image data. It is determined whether or not the data is recognized, and a signal N for instructing the continuation of the acquisition or update of the image data is given to the image analyzer 6.

The object 10 is sufficiently illuminated to make it bright, and the background is made dark so that the object can be easily recognized by binarization. Of course, when the object is close to black, the background may be close to bright white to facilitate identification.

FIG. 2 is a block diagram showing a detailed configuration of the first embodiment. Corresponding to FIG. 1, reference numerals 61 to 63 denote parts for outputting the best image of the image analyzer 6, and 71 to 75 denote detailed structures of the best image determination device 7. Imaging camera 4
The image data picked up in is stored in the first memory 61 which stores the current image data. The image data stored in the first memory 61 is moved to the second memory 62 as the previous image data. The memory selector 63 uses the signal N sent from the best image determination unit 7 to generate the first memory 61.
Alternatively, one of the valid image data stored in the second memory 62 is selected and output as the best image, or is not output, and the memory contents are updated.

The field of view of the imaging camera 4 is set so that one object 10 is completely entered in one image pickup, but two or more objects 10 are not completely entered.

The sampling unit 71 calculates one-dimensional data representing the representative portion of the object 10 from the image data from the image pickup camera 4. The binarization unit 72 binarizes the object and the background by setting thresholds so that the portion of the one-dimensional data corresponding to the object 10 has a level of 1 and the background has a level of 0. The object 10 may be inverted to the 0 level and the background to the 1 level. In the following description, the object 10 is 1, and the background is 0. The effective visual field determination unit 73 determines whether or not one and only one moving body is completely included in the screen with respect to the binarized one-dimensional binary data, and the included data is referred to as the subsequent data. The image data is effective for making a judgment. An image containing an image of one complete object 10 and an image of an incomplete object 10 is also effective image data.

FIG. 3 is a diagram showing an effective visual field and an invalid visual field. The effective visual field is one in which the object 10 is completely included, and the ineffective visual field is one in which the object 10 is not completely included. Note that, as described above, the field of view is set so that the two or more objects 10 do not completely enter. The combination of 0 and 1 on the left is a change pattern representing an image of each field of view. 0-1-0 represents image data in which the background 10 is on both sides and the object 10 is 1 in the center and is present in a perfect form. The leftmost 1 of 1-0-1-0 represents the shape of the incomplete object 10. The shape of the complete object 10 is the case where there are 0s on both sides of 1. The layout pattern of the invalid visual field is not such a change pattern.

The center deviation calculating section 74 is set to 1 of the effective image data.
The center of the positions of both ends of the object 10 obtained from the dimensional binarized data is set as the center position of the object 10, and the amount of deviation between this center position and the center of the screen is obtained. It also has a memory capable of holding the center position and the shift amount of the previous effective image data. The current center position of the object 10 is Pn, and the shift amount is δ
n, the previous center position is Pp, and the shift amount is δp.

The best image determining section 75 is a center shift calculating section 74.
The following three types of judgments are generated from the data of Pn, δn, Pp, and δp obtained in step 1 and the set allowable deviation δo. The current image is the best image. The previous image is the best image. Continues to capture images, leaving it to the next set of images.

In the following case, it is determined that the selection signal is generated so as to fetch the current image data. | Δn | ≦ δo (1) That is, this is the case where the absolute value of the current shift amount δn is equal to or less than the allowable shift amount δo. Moreover, it is a case where the following formula is materialized. || Pn + (Pn-Pp) | -F / 2 |> | δn | (2) where (Pn-Pp) is the object 1 on the previous screen.
0 represents the distance traveled to get the current screen, and an estimate that it will move there on the next screen. F
/ 2 represents the center of the screen, and the left side of the equation (2) represents the expected shift amount of the center of the object on the next screen. In equation (2), the absolute value of the deviation amount on the next screen is the absolute value δ of the deviation amount on the current screen.
The case where it is larger than n is shown. At this time, the current image data is taken in even if the expression (1) is not established. This is because at least the current screen will be closer to the center than the next screen.

When the absolute value δn of the current displacement amount is larger than the absolute value δp of the previous displacement amount, the selection command is issued to capture the image data of the immediately preceding displacement described in (2) Is. | Δn |> | δp | (3)

If it does not belong to any of the above, it becomes all.

The judgment criteria described above are the operations when the contents of both the first and second memories are valid images, but at least at least one of the memories is an invalid field of view image. Follows the table below. Current image Front view image operation Invalid Invalid Image capture continued Valid Invalid Image capture continued Invalid Invalid Front field image adopted

Once the best image has been captured, there are no more valid images in the field of view, ie 0-1-0,0-1.
As long as -0-1, ... continues, the dummy cycle is repeated.

The operation of the block diagram shown in FIG. 2 can be easily configured by a software program.
However, since it takes a long processing time to perform calculation by software, it is generally unsuitable for fast online inspection. For high speed online inspection, an example of performing calculation by a hardware circuit is shown below.

Next, a circuit configuration example of the sampling section 71 will be described. FIG. 4 is a diagram showing the relationship between the horizontal scanning line and the image of the object. In order to check whether or not the object 10 is imaged at an appropriate position on the screen, that is, in the substantially central portion of the screen, a vertical position near the maximum width of the object 10, that is, a substantially vertical center in FIG. It suffices to check the image data on the horizontal scanning line. By doing so, the two-dimensional image data can be made one-dimensional, and the handling becomes easy. But one
Since the data of the horizontal scanning line of one book is weak against noise and the like, it is better to use the average value of a plurality of upper and lower lines. In FIG. 4, when the horizontal scanning lines are sequentially numbered from the top to H0 to Hn, for example, one-dimensional binarized data using a binarized image of an average image of four lines Hm0 to Hm3 in the central portion is taken out. The circuit will be described.

FIG. 5 is a diagram showing a sampling circuit and a binarization circuit. Reference numeral 711 denotes a vertical scanning timing generator of the imaging camera 4, which determines the timing of generating the horizontal scanning line Hk. A video signal digitized for each horizontal scanning line is input to the addition gate 712, and only the data of a preset horizontal scanning line, that is, Hm0 to Hm3 in the case of FIG. 4, is passed and the data of other horizontal scanning lines are masked. So that it is not output. The 1H delay line 713 is a memory that holds the data for one horizontal scanning line added by the adder 714. The adder 714 is an adder that adds each pixel on the horizontal scanning line and each pixel on the 1H delay line 713 at the same position in the horizontal direction. The result of the addition is stored again in the 1H delay line 713, so that the output of the adder 714 is the integrated value of the horizontal scanning lines that have passed through the addition gate. Since the average value can be obtained by dividing the integrated value by the number of added lines, the integrated value can be said to be the average value itself.

The threshold setter 722 sets a threshold for distinguishing the object 10 from the background. The binarizer 721 binarizes the one-dimensional data accumulated by this threshold value,
An averaged one-dimensional binary image is output. Although the data of four horizontal scanning lines are added in the above description, the horizontal scanning lines to be added and the number thereof can be adjusted by changing the timing of the vertical scanning timing generator 711. The 1H delay line 713 is initialized (clears each pixel) for each image data.

Next, a circuit example of the effective visual field determination section 73 will be described. In the one-dimensional binarized image output from the binarizer 721, the object is represented by 1 and the background is represented by 0. Therefore, by using this, one object is perfectly displayed on the screen on the horizontal scanning line. It is possible to check whether it appears (on the one-dimensional binarized image). For this, the change pattern described in FIG. 3 is extracted from the one-dimensional binarized image, and it is checked whether it is valid or invalid by comparing it with a change pattern representing a preset effective visual field and invalid visual field.

FIG. 6 is a diagram showing an example of a circuit representing the effective visual field determination section 73. Although the effective visual field determination unit 73 can be easily realized by software, this circuit is provided because the hardware can perform higher speed processing. 73
1 is a polarity inversion detector, and the value of the one-dimensional binary image is 0 →
The shift signal SH is generated every time 1 or 1 → 0. Reference numeral 732 is a register for synchronizing the timing, which delays the output of data for one clock and sends out the pixel after the polarity change. Reference numerals 7320 to 7324 are 1-bit registers, and form a 5-bit shift register as a whole. The contents of the shift register are sequentially shifted in the arrow direction by the shift signal SH. The reason for using the 5-bit shift register is to match the 5-bit maximum change pattern shown in FIG. A determination ROM 734 compares the change pattern output from the shift register with the change patterns of the effective visual field and the invalid visual field shown in FIG. 3, which are stored in advance, and makes a determination. This determination result is latch 73
It is held for a required period at 5 and is output by the strobe signal ST. The strobe signal ST is, for example, Hm shown in FIG.
It is convenient at the end of 3, etc. The shift register 73
20 to 7324 are also initialized for each screen (one frame).

Next, a circuit example of the center deviation calculating section 74 will be described. In order to establish this circuit, the field of view of the imaging camera 4 is adjusted so that one object 10 is completely imaged on the screen and two or more objects 10 are not completely imaged on the screen. This is because the analysis becomes impossible when the two objects 10 completely enter the screen. The object 10
As long as one and only one is perfectly visible, it is okay to have an imperfect object together.

FIG. 7 is a diagram showing an example of a circuit representing the center deviation calculating section 74. The pixel synchronization pulse is a system clock common to the entire system, and one pulse is generated each time image information moves by one pixel. The pixel synchronizing pulse is counted by the horizontal pulse counter 741. Therefore, the output Hp of the horizontal pulse counter 741 represents the current horizontal position of the one-dimensional binary image in real time. 742,743
Holds the value of the counter output Hp when the clock signal CK is input to the register. 744 and 745 are polarity change detectors, 744 detects the first rising edge of the one-dimensional binarized image and outputs it as a clock signal CK to the register 742, and 745 detects the falling edge following the first rising edge, and the clock signal It is output to the register 743 as CK. As shown in FIG. 3, in the change pattern of the effective visual field, the first rising edge of the one-dimensional binarized image indicates the left end position of the object 10 and the trailing edge thereof indicates the right end position of the object 10. As a result, the register 742 holds the left end position of the object 10 and the register 743 holds the right end position of the object 10.

The averager 746 is composed of both registers 742 and 743.
The center position of the object 10 is calculated by taking the average of the left end and right end positions held by. The averaging device 746 is, in principle, only a two-input adder, so that it is easy to realize. F is the total number of pixels in the horizontal direction, for example, 256 or 512 is used. F / 2 indicates the center coordinate in the horizontal direction of the screen. The subtractor 747 calculates the difference δ between the center position P of the object 10 and F / 2. The difference δ is the amount of deviation δ from the center of the screen of the object 10.
Represents Numerals 748 and 749 hold data of the image immediately preceding the current image in the memory, 748 holds the center position P of the object 10, and 749 holds the shift amount δ. The current center position of the object is represented by Pn, the previous center position by Pp, the current displacement amount by δn, and the previous displacement amount by δp.

FIG. 8 is an explanatory diagram of the center shift calculating circuit shown in FIG. As an example, the change pattern 1-0-1-0-
The case of 1 is shown. For the one-dimensional binarized image of this change pattern, the point a is the first rising edge detected by the change detector 744, and the point b is the first falling edge following this first rising edge. To be detected. Other rising edges and falling edges are not detected. Thereby, the positions of the left end a and the right end b of the object 10 can be detected. Pn indicates the center of the points a and b. Also F
/ 2 indicates the horizontal center of this screen. δn is this F
The amount of deviation between / 2 and Pn is shown. It can be seen that the center Pn of the object 10 is on the right side or the left side of the screen depending on whether the shift amount is positive or negative.

Next, a second embodiment will be described. This embodiment is different from the first embodiment in that the first memory 61, the second memory
The usage of the memory 62 is changed, and the others are the same.
In the first embodiment shown in FIG. 2, since the current image data is stored in the first memory 61 and the previous image data is stored in the second memory 62, the screen is changed and new current image data is input. Then, this is stored in the first memory 61, and the contents of the first memory are transferred to the second memory 62 to be the previous image data. That is, the first memory 61 and the second memory are 2
It works like a dimensional data shift register. However, image data is two-dimensional and has a large amount of information, which requires a large amount of time for one operation. In order to solve this, in the second embodiment, the image data is alternately stored in the first memory 61 and the second memory 62, and the selection command also corresponds to this.

FIG. 9 is a basic conceptual diagram of the image memory of the second embodiment. The best image determination device 7 is the same as in the first embodiment. Normally, as shown in FIG. 2, it is possible to transfer data to the second memory one after another via the first memory and issue a selection command to the fixed first memory and second memory. As described above, the operation of transferring the new current image is required each time, and the operation time is required. Therefore, the method of FIG. 9 is used in order to perform higher speed processing by hardware. The first memory 61 and the second memory 62 are image memories for one screen which are completely equal to each other. Writing can be similarly performed for both 61 and 62. However, only one of them can be accessed at a time. The access order is alternating, and after writing the image data of the current screen in the first memory 61, the image data of the next screen is written in the second memory 62. Reading can be performed from either 61 or 62 by an inversion selection command. First
The current image data is stored in one of the memory 61 and the second memory 62, the image data of the previous screen is stored in the other, and the current image data is stored in either one. Follow

When the writing is performed in the first memory 61, the image data of the immediately preceding screen: the second memory 62, the image data of the current screen: the first memory 61, the writing is performed in the second memory 62. Image data of the previous screen: first memory 61 image data of the current screen: second memory 62

If the contents stored in the first memory 61 and the second memory 62 are changed every time the frame is changed (the screen is changed) by such a method, it is necessary to deal with the selection command. It is easier to create the selection command assuming that the current image data and the previous image data are stored in the fixed memories, respectively. Therefore, the selection command created in this way can be changed according to the frame change. Inverted reverse selection command,
It corresponds to the change of memory.

FIG. 10 is a block diagram of the image memory related to the second embodiment. The input image is two-dimensional image data from the imaging camera 4 shown in FIG. The pixel synchronization pulse is a write command to the first memory 61 and the second memory 62, and the frame signal is a signal generated each time the imaging camera 4 advances by one frame. The memory selector 63 is shown in FIG.
This is the same as the case of 1., the data from the first memory 61 or the second memory 62 is input from the D1 or D2 terminal, selected by the value of the inversion selection command signal N ', and selectively output from the Y terminal. Reference numeral 64 denotes a T flip-flop, which reverses the polarity output every time one screen changes depending on the frame signal.
As a result, the write signal based on the pixel synchronizing pulse applied to the first memory 61 and the second memory 62 is not AND gate 66.
Alternately prohibited at A and 66B. That is, each frame signal is alternately written in one of the memories 61 and 62. On the other hand, the selection command N to the memory selector 63 does not operate as it is, but the polarity is inverted by the XOR gate 65 in accordance with the output of the T flip-flop 64, and an inversion selection command N'corresponding to the alternate conversion of the memories 61 and 62 is generated. Then, it is added to the S terminal of the memory selector 63. Since this operation does not need to be grasped from the outside, that is, it is transparent, the control is not complicated by adopting this method.

As described above, a normal image memory operates equivalently as a two-dimensional shift register with a small amount of additional logic circuits, and the operation time required for actual image transfer becomes completely unnecessary.

[0046]

As is apparent from the above description, the present invention has been conventionally required by picking up an image of a moving object at regular intervals and selecting the best image data from the image data. It does not require a moving distance measuring device for the object carrier, a trigger generator that opens the shutter of the imaging camera, and the imaging camera can be a normal shutter camera that opens and closes at a fixed cycle instead of the expensive random shutter system. Is extremely simple and inexpensive. Further, by alternately storing the current screen and the previous screen in the two image memories, it is not necessary to transfer the image data from one memory to another memory, which enables further high speed processing.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of the first embodiment.

FIG. 3 is a diagram illustrating determination of an effective visual field and an invalid visual field.

FIG. 4 is a diagram showing a relationship between a horizontal scanning line and an image of an object.

FIG. 5 is a diagram showing a sampling circuit and a binarization circuit.

FIG. 6 is an effective visual field determination circuit diagram.

FIG. 7 is a center shift calculation circuit.

FIG. 8 is a diagram illustrating a center shift calculation circuit.

FIG. 9 is a basic conceptual diagram of an image memory according to a second embodiment.

FIG. 10 is a configuration diagram related to an image memory according to a second embodiment.

FIG. 11 is a configuration diagram of a conventional moving body imaging apparatus.

[Explanation of symbols]

 4 Imaging Camera 6 Image Analyzer 7 Best Image Judgment Device 61 First Memory 62 Second Memory 63 Memory Selector 71 Sampling Section 72 Binarization Section 73 Effective Field of View Judgment Section 74 Center Deviation Calculation Section 75 Best Image Judgment Section

Claims (6)

[Claims] 1. A moving body moving in front of a fixed image pickup device is imaged at regular time intervals, current image data and previous image data are stored, and the moving direction of the moving body for both image data is stored. The amount of deviation between the center coordinates of the image and the center of the screen is calculated, and based on this amount of deviation, it is determined whether to use any image data or continue image capture as it is. Acquisition method. 2. A fixed image pickup device for picking up an image of a moving body at fixed time intervals, a sampling unit for taking out a representative range of image data picked up by the image pickup device as one-dimensional data, and moving the one-dimensional data. A binarization unit for binarizing the data of the body and the back shadow, an effective visual field determination unit for determining effective image data in which the entire image of the moving body is on the screen for the binarized data, and the imaging device. An image memory for storing the captured current image data and the immediately preceding image data, and an amount of deviation between the center position of the moving body and the center of the screen of the binarized data extracted by the determination of the effective visual field determination unit. Best image determination for determining use of the current image data and the previous image data of the image memory or continuation of image capture based on the center shift calculating unit to be calculated and the shift amount calculated by the center shift calculating unit And a moving body image capturing device. 3. The moving object image according to claim 2, wherein the sampling unit calculates one-dimensional data by vertically adding one-dimensional data of a plurality of horizontal scanning lines in a predetermined range. Capture device. 4. The effective visual field determination unit assigns a level of 0 or 1 when the binarized data changes from 0 to 1, and when the binarized data changes from 1 to 0. Then, the other level is assigned to create a change pattern in which these changes are represented by an alternating arrangement of 0 and 1, and one moving object is surely included in the screen in comparison with the standard change pattern created in advance. The moving image capturing apparatus according to claim 1, wherein it is determined whether or not the moving body image is captured. 5. The center deviation computing unit binarizes an average value of a change position indicating that the moving body is first detected in the binarized data and a subsequent change position indicating the disappearance of the moving body. The moving object image capturing apparatus according to claim 1, wherein the apparatus is the center of the converted data. 6. The best image determination means is configured such that the image memory includes a first memory and a second memory, and image data of a screen changed every time the screen is changed is alternately stored in the first memory and the second memory. The section shows the instruction to select the current image data and the image data of the previous screen, assuming that the first image data is fixedly stored in the first memory and the previous image data is fixedly stored in the second memory. 2. The moving object image capturing apparatus according to claim 1, wherein the first selection command is output by changing the first selection command to a second selection command that is the inverted first selection command in synchronization with the screen change.