JPH08294113A - Image processor - Google Patents

Abstract

PURPOSE: To provide a visual check device in which an undesired signal resulting from a lighting condition is accurately eliminated without the use of complicated image processing and a large sized device. CONSTITUTION: Plural image frame signals a, b are obtained by conducting image pickup for each of plural times of lighting from different directions through the control of light sources 21-24. Then each picture element signal outputted from the same picture element in each of the image frame signals a, b (hereinafter called same picture element signal) is given to an AND circuit 33, in which ANDing is conducted to obtain an image frame signal (c) for discriminating the acceptance of a checked article. Thus, even when an undesired signal intrudes due to undesired reflection signal to signals of one frame image obtained by pickup with a lighting in a direction, since other frame image signal obtained by pickup with a lighting in other direction does not often increase the undesired signal, two or over of same picture element signals obtained sequentially from the same picture elements of both the image frame signals are subjected to logic arithmetic operation for each same picture element to simply eliminate the undesired signal in an excellent way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, for example, processes a two-dimensional image signal (image frame signal) output from an image pickup means attached to a robot hand to perform inspection, object recognition, operation control of equipment, and the like. The present invention relates to an image processing device that obtains an image signal.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 61-293657 discloses an illumination condition that cannot be avoided by a single image frame signal under a single illumination condition (to be exact, a background in an imaging region or an imaging target). In order to reduce unnecessary signals due to (reflection state), a plurality of light sources are provided at different spatial positions to illuminate an imaging target, control means for individually controlling lighting of each light source, and each light source. From the image signal processing means, an image pickup means for sequentially outputting a plurality of image frame signals obtained by sequentially picking up an image pickup object under different lighting conditions, an image signal processing means for binarizing each image frame signal, and an image signal processing means. Disclosed is an image processing apparatus (image inspection apparatus) including a determination unit that determines the quality of an imaging target based on a plurality of output binarized image signals.

The processing method of a plurality of binarized image signals specifically disclosed in the above publication is as follows. That is, the white area (or black area) in each binary image frame signal
The area, the perimeter, and the vertical or horizontal length of each are calculated and compared with predetermined threshold values.

[0004]

According to the discrimination method of the above publication, the quality of a plurality of image frame signals picked up by changing the illumination direction as described above is judged separately, and the final judgment is made based on those judgment results. Since this is a method, such final determination must be finally determined to be good when all the determinations of each image frame signal are all good, and in the end, the illumination light irradiation direction Change only and inspect multiple times.

However, if the inspection is performed a plurality of times by simply changing the irradiation direction of the illumination light, the image of the object to be imaged (inspection image) due to the relationship between the irradiation direction of the illumination light and the unnecessary reflected light or unnecessary shadow. It is difficult to remove unnecessary signals that are mixed in with the background image, and it is unavoidable to perform image determination based on the existence of these unnecessary signals. Of course, in order to avoid unnecessary reflection (especially reflection of the light source on a smooth surface) and the generation of shadows, it is possible to devise a surface light source, etc., but for inspection of the imaging target etc., image the light from a predetermined direction such as oblique light. There are cases where it is desired to illuminate an object to enhance the contour, or where a spot light source has to be adopted due to the layout at the production site, and in such cases, the above-described unnecessary reflection and shadow are generated.

Further, in the multiple inspection method of the above publication, the circuit scale of the image signal processing unit such as the image memory is increased,
In addition, there is a drawback that the processing time becomes long. Explaining specifically with an example, for example, when illuminating the periphery of the imaging target from a certain oblique angle, if oil adheres to the surface of the imaging target or the surface of the support table on which the imaging target is placed, The illumination light to be scattered may be totally reflected and may enter the TV camera, and an area that should originally be a black area may become a white area. The process of removing such a false signal is troublesome and requires complicated image processing.

In addition to the oil surface, unnecessary reflected light from the object to be imaged or the mounting table itself on which it is mounted may occur depending on the illumination direction, and the same problem as described above occurs. Further, the above-described generation of unnecessary reflection and shadow poses a problem not only in image inspection but also in image recognition of an object and image recognition. The present invention has been made in view of the above problems, and provides an image processing apparatus capable of accurately removing unwanted signal removal due to illumination conditions without using complicated image processing and a large-scale apparatus. That is the first purpose.

[0008]

In the first configuration of the present invention, a plurality of image frame signals are obtained by taking an image each time illumination is performed a plurality of times from different directions. Then, among the image frame signals, each pixel signal output from the same pixel (hereinafter referred to as the same pixel signal) is subjected to a predetermined logical operation to be converted into an image frame signal suitable for the subsequent processing. In this way, 1 obtained by imaging with illumination from a certain direction
Even if an unnecessary signal is mixed into a single image frame signal, that is, a signal forming an image of one frame due to unnecessary reflection, it is not included in the other one image frame signal obtained by illuminating from another direction. Often not included, so
These unnecessary signals can be satisfactorily and easily removed by logically calculating, for each same pixel, two or more same pixel signals sequentially obtained from the same pixel of both image frame signals.

That is, it is possible to remove an undesired signal due to illumination conditions without using complicated image processing and a large-scale device. In the second configuration of the present invention, a plurality of images obtained by picking up the same image pickup target from a plurality of different image pickup positions are used. First, the displacement of the coordinate position of each imaging target in each image due to the displacement of the imaging position is corrected, and then the logical operation of each pixel signal of each displacement-corrected image frame signal is sequentially executed for each same pixel position.

By doing so, unnecessary signals such as unnecessary reflections and shadows can be removed as in the first configuration. In the third configuration of the present invention, a logical product operation of the displacement-corrected image frame signals is further performed in the second configuration. By doing so, it is possible to remove a difference in images (hereinafter referred to as an image error due to stereoscopic parallax) that occurs when a stereoscopic object is imaged from different imaging positions.

In a fourth structure of the present invention, the TV camera and the TV camera are further moved between respective image pickup positions in the second structure to obtain the plurality of image frame signals. With this configuration, the second configuration can be easily realized. In the fifth configuration of the present invention, each image frame signal is further obtained by a plurality of TV cameras individually arranged at a plurality of different image pickup positions in the second configuration.

With this configuration, image processing can be performed at high speed, and image processing can be performed even when the image pickup means and the image pickup target are relatively moving. In a sixth configuration of the present invention, in addition to the second configuration, the light introduced from a plurality of different image capturing positions is switched by the optical light changeover switch unit and sequentially input to the common image capturing unit. This makes the system configuration simple.

In a seventh structure of the present invention, the logical operation means is further composed of an AND circuit or software means equivalent thereto in the first or second structure. By doing so, it is possible to easily remove an unnecessary white area caused by unnecessary reflection. In a preferred aspect, this configuration applies the present apparatus to an imaging target to which an oil film is attached. That is, originally,
If oil, that is, an oil film, adheres to the surface that is determined to be the black region, total reflection of the light source or concentrated reflection in a predetermined direction is likely to occur. Therefore, in the appearance inspection of the background on which the oil film is adhered or the image pickup target, the present configuration can greatly improve the determination accuracy.

According to an eighth structure of the present invention, in addition to the first or second structure, a plurality of pixel signals output for each lighting condition change under a plurality of lighting conditions in which the lighting direction changes from the same pixel. Select a lower level signal. By doing so, the unnecessary reflection can be removed. According to a ninth configuration of the present invention, in addition to the above-mentioned first or second configuration,
At least a pair of light sources arranged on both sides of the image pickup means are turned on at the same time. By doing so, it is possible to easily reduce the shadow input to the image pickup means.

In the tenth structure of the present invention, the first and second light sources are arranged on both sides of the image pickup means, and the third and fourth light sources are arranged on both sides of the image pickup means at different positions. It The first and second image frame signals obtained by turning on the first and second light sources in the first image pickup period and turning on the third and fourth light sources in the second image pickup period are supplied to each pixel. The value is converted into a logical product for each pixel. If it does in this way, the following effects will be produced.

The provision of a camera (imaging means) or a light source on the robot hand is extremely advantageous in practical use in that the hand does not enter the field of view of the camera or the illumination field of the light source, but the degree of freedom of movement of the hand is limited. From the viewpoint of securing, it is quite a burden to attach a camera alone, and it is extremely difficult to use a uniform illumination light source or a large planar light source on the hand. A point light source such as a light is most suitable.

However, when the radiated light from such a point light source (non-uniform illumination light source) is reflected by a smooth surface such as a grinding surface or an oil surface on the grinding surface, even if the same plane is imaged, there is a problem. In a region (hereinafter, also referred to as a shining region), the lightness becomes extremely high due to the incidence of this reflected light (a portion that is originally black as a binarized signal is white). This problem peculiar to using a light source (non-uniform illumination light source) as the illumination light is that two image frame signals which are signals of different imaging periods are binarized for each pixel and then the logical product of them is taken. This solves the problems described above.

However, when the point light source is arranged on one side of the camera, the amount of reflected light which enters the camera from the work surface on the side opposite to the point light source with the camera in between enters the camera from the work surface on the camera side. The amount of reflected light is significantly reduced. Further, if the work has irregularities or steps, a shadow is generated, and the signal of the pixel in this shadow part becomes black due to the above-mentioned logical product, and a normal work image cannot be obtained.

In order to reduce the shadow and to reduce the variation in the amount of light reflected to the camera due to the positional relationship with the point light source, a plurality of point light sources are arranged around the camera and they are turned on at the same time for imaging. Just go. But if you do this
Since the number of shining areas (high bright spots) in the first and second image frame signals increases, the possibility that the shining areas of both image frame signals overlap will increase. If this overlap occurs, the shining area cannot be removed by the logical product processing.

That is, when the number of simultaneously lit light sources provided in the above-mentioned robot hand is small, unnecessary shadows and brightness variations (as seen from the camera) in each part of the work occur, and when the number of these simultaneously lit light sources increases, both image frames are displayed. The signal shining areas (high bright spots) overlap and cannot be removed by logical product processing. This configuration is made in order to improve this problem. First and second light sources that are simultaneously turned on are arranged on both sides of the image pickup means, and they are arranged at positions different from them (preferably at positions orthogonal to them). The third and fourth light sources that are turned on at the same time are arranged on both sides of the image pickup means. By doing so, it is possible to effectively reduce the shadows in both image frame signals, and also to effectively reduce the overlap of the shining areas (high bright spot areas) of both image frame signals. The work image of can be obtained.

Further, in this configuration, since the scale can be removed by the binary information processing called the logical product operation, the storage and processing of each pixel signal becomes simple. According to the eleventh configuration of the present invention, a light source is provided on the side of the image pickup means at the tip of the robot hand, and the image frame signal obtained by turning on the light source is binarized for each pixel to obtain a binarized image. Get the frame signal.
Particularly, in this configuration, the threshold level is individually stored for each pixel in advance, and the image frame signal is binarized for each pixel using the threshold level. If it does in this way, the following effects will be produced.

The provision of a camera (imaging means) or a light source in the robot hand is extremely advantageous in practical use in that the hand does not enter the field of view of the camera or the illumination field of the light source, but the degree of freedom of movement of the hand is limited. From the standpoint of securing, it is quite a burden to attach a camera alone, and it is extremely difficult to use a uniform illumination light source or a large planar light source on the hand. A point light source such as a light is most suitable.

However, the reflected light emitted from such a point light source (non-uniform illumination light source), reflected from the work or the background, and incident on the camera is most effective when reflected from an intermediate point between the camera and the light source. It is large and sharply decreases with distance from the optical axis of the camera, and as a result, the amount of reflected light entering the camera varies. This configuration is made in order to solve this problem in the case of a light source provided in the robot hand. Since the binarization processing is performed for each pixel according to a threshold level stored in advance, the above-mentioned incident light amount is The problem of variation from time to time is solved.

In the twelfth structure of the present invention, a first light source arranged on one side of the image pickup means and a second light source arranged on the other side of the image pickup means (a side different from the one side). Are sequentially turned on to sequentially take out the first and second image frame signals, the image frame signals are binarized for each pixel, and the logical product operation is performed for each pixel to remove the above-mentioned light. In particular, in this configuration, the signals of the same pixel of both image frame signals are individually binarized at different threshold levels, so that the following operational effects are achieved.

The provision of a camera (imaging means) or a light source on the robot hand is extremely advantageous in practical use in that the hand does not enter the field of view of the camera or the illumination field of the light source, but the degree of freedom of movement of the hand is limited. From the viewpoint of securing, it is quite a burden to attach a camera alone, and it is extremely difficult to use a large area light source on the hand. A light source is most suitable.

However, when the radiated light from such a point light source is reflected on the ground surface or a smooth surface such as an oil surface on the ground surface,
Even if the same plane is imaged, in a certain area (hereinafter, also referred to as a “shining area”), the brightness becomes extremely high due to the incidence of the reflected light (a portion that is originally black as a binarized signal becomes white). This problem peculiar to using a point light source (non-uniform light source) as the illumination light is that two image frame signals, which are signals of different imaging periods, are binarized for each pixel, and their logical product is calculated. By taking it, it is solved as described above.

However, since the positions of the first light source and the second light source are different, the amount of reflected light that is reflected from these light sources at a predetermined point in the image pickup area and is incident on the camera (image pickup means) is greatly different. It turns out that it may be converted to a value level. This configuration is made in order to solve this problem, and different threshold levels are stored in advance for the same pixel of both image frame signals, and both image frame signals are detected by these threshold levels. Binarization separately solves the above problem.

In the thirteenth structure of the present invention, the first light source arranged on one side of the image pickup means and the second light source arranged on the other side of the image pickup means are sequentially turned on to turn on the first light source. , The second image frame signal is sequentially taken out, both of these image frame signals are binarized for each pixel, and a logical product operation is performed for each pixel to remove the shine. In particular, in this configuration, the state quantity related to the average signal level of the entire image frame signal is extracted, and the state quantity is set in the direction in which the number of white pixels in the binarized image frame signal approaches the predetermined reference number. Based on this, the threshold level for each pixel is shifted by the same amount. If it does in this way, the following effects will be produced.

The provision of a camera (imaging means) or a light source on the robot hand is extremely advantageous in practical use in that the hand does not enter the field of view of the camera or the illumination field of the light source, but the degree of freedom of movement of the hand is limited. From the standpoint of securing, it is quite a burden to attach a camera alone, and it is extremely difficult to use a uniform illumination light source or a large planar light source on the hand. A point light source such as a light is most suitable.

However, when the work is imaged by the set of the camera and the light source fixed to the robot hand as described above, the point light source emits light due to the subtle changes in the work posture and the hand posture. In some cases, the amount of reflected light reflected by the surface of the work and incident on each pixel of the camera (imaging unit) changes uniformly. For example, if the reflecting surface of the work is slightly tilted with respect to the optical axes of the camera and the point light source that are parallel to each other, the amount of reflected light that enters the camera from this reflecting surface will vary slightly from pixel to pixel, but this is generally the case. Change uniformly.

The present configuration is made in order to solve this problem, and extracts the change amount of the average signal level of the entire image frame signal, and accordingly shifts the threshold level of each pixel by the same amount. Then, the change in the average signal level is canceled (compensated). In the fourteenth configuration of the present invention, the threshold level is changed so that the number of white pixels in the binarized image frame signal becomes a predetermined reference value in the thirteenth configuration. Such an overall change in the amount of reflected light that enters the camera can be easily made constant, and even if a large amount of reflected light is incident from some pixels as in the above-mentioned scale, it is the overall change in the amount of reflected light. The problem of fluctuating can be prevented.

In the fifteenth aspect of the present invention, the tenth to tenth aspects described above are provided.
Since it has 14 configurations, an excellent robot hand-mounted image processing apparatus as a whole can be realized.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) (Structure Description) One embodiment of an image processing apparatus of the present invention is shown in FIG.
This will be described with reference to FIG. FIG. 1 is a side view showing a main part of this image processing apparatus, FIG. 2 is a layout view showing a planar layout of a light source device 10 used in this image processing apparatus, and FIG. 3 is a block circuit diagram of this image processing apparatus. FIG. 4 is an explanatory diagram for explaining the logical product processing that is a feature of this image processing apparatus.

This image processing apparatus, as shown in FIG.
TV camera (imaging means) 1, light sources 21 to 24, TV
An image signal processing circuit (image signal processing means) 3 for signal-processing an image frame signal output from the camera 1 to output a processed image signal, and an image for processing the processed image signal to determine whether the image pickup target is good or bad. A signal processor 4 and a timing controller (lighting control means) 5 are provided.

The TV camera 1 having an optical axis that hangs vertically picks up an image of a punched product (imaging target) 7 of a predetermined three-dimensional shape on a pallet 6, and the light source is provided on the side, front, back, left and right of the TV camera 1. 21 to 24 are individually arranged. More specifically, the TV camera 1 is formed integrally with the light sources 21 to 24 and is movable in the front-rear direction and the left-right direction (horizontal direction) relative to the press-punched product 7 on the pallet 6. Also,
An oil film 8 is attached to the upper surface of the pallet 6, and an oil film 80 is also attached to the upper surface of the stamped product 7.

The image signal processing circuit 3 binarizes the image frame signal output from the TV camera 1 for each pixel and outputs it as a binarized image frame signal.
And a frame memory 32 for storing one frame of the binarized image frame signal output from the comparator 31.
And an AND circuit 33 which performs a logical product operation of the read binary image frame signal read from the frame memory 32 and the binary image frame signal output from the comparator 31 for each pixel.

The image signal processor 4 calculates a predetermined inspection amount from an input signal on the basis of an image processing program and a judgment program incorporated therein. However, the judgment routine itself is not the gist of the present embodiment, and therefore no more. The detailed description of is omitted. The timing controller 5 is a circuit that controls the timing of the TV camera 1, the light sources 21 to 24, and the frame memory 32, but the specific circuit description thereof is omitted.

The light sources 21 to 24 are arranged at right angles to the optical axis of the TV camera 1 and at 90 degrees from each other, and are controlled by the timing controller 5 to obtain a first image frame signal. Light sources 21, 23 during the period
Is turned on, and the light sources 22 and 24 are turned on during the second imaging period in which the second image frame signal is obtained. In this embodiment, since the light sources 21 and 23 are symmetrically arranged with the TV camera 1 interposed therebetween, the lighting of them makes it difficult for the press-punched product 7 existing immediately below the optical axis of the TV camera 1 to be shaded. Similarly, since the light sources 22 and 24 are symmetrically arranged with the TV camera 1 interposed therebetween, the lighting of them makes it difficult for the press-punched product 7 existing immediately below the optical axis of the TV camera 1 to be shaded.

(Explanation of Operation) When the TV camera 1 stands still right above the pallet 6, a start signal is output from an external controller (not shown) to the timing controller 5, and the timing controller 5 outputs a TV signal based on the start signal. While the left and right light sources 21 and 23 of the camera 1 are turned on, the TV camera 1 is instructed to image the upper surface of the pallet 6 and the punched product 7 placed on the pallet 6, and the TV camera 1 makes the first frame for one frame. The image frame signal A is serially output. This signal output is executed in synchronization with the vertical and horizontal synchronizing signals from the timing controller 4 to the TV camera 1, and the first image frame signal is binarized by the comparator 31 having a predetermined threshold value and the frame memory 32. Stored in. During this image pickup period, the timing controller 4 outputs the lighting signal W and the lighting is performed.

After that, when the storage of the binarized image frame signal in the frame memory 32 is completed, the timing controller 4 causes the light sources 22 before and after the TV camera 1,
While turning on 24, the TV camera 1 is instructed to take an image again, and T
The V camera 1 uses the second image frame signal B for one frame.
In the same manner as above, and the second image frame signal B is also binarized by the comparator 31.

The timing controller 4 outputs a read signal R to the frame memory 32 when the image frame signal is output.
And the vertical and horizontal synchronization signals described above are output, whereby the frame memory 32 outputs the first binarized image frame signal A,
The binary image frame signal B output from the comparator 31 is read at the same pixel timing. In this way, the two binarized image frame signals A and B that are synchronized and output are logically ANDed for each pixel by the AND circuit 33, and the output, that is, the logical product of the binarized image frame signals is output. The signal is output to the image signal processor 4 for further processing.

Next, the operation and effect of the above-described AND operation will be described with reference to FIG. In FIG. 4, (a) shows the image A represented by the first binarized image frame signal, and 71 and 72 are images of the light sources 21 and 23 concentratedly reflected by the oil film 8 attached to the upper surface of the pallet 6. In FIG. 4, (b) shows the image B represented by the second binarized image frame signal, and 73 and 74 are images of the light sources 22 and 24 concentratedly reflected by the oil film 8 attached to the upper surface of the pallet 6.

Since the light sources 21 to 24 are arranged apart from each other, the images 71 to 74 are formed at different portions on the oil film 8. Therefore, by performing the logical product operation of the image a and the image b for each same pixel, as shown in FIG. 4C, the concentrated reflection by the oil film 8 can be removed very easily. (Modification) FIG. 5 shows a different arrangement example of the light sources 21 to 24. (A) shows the light sources 21 to 24 arranged at respective vertices of a rectangle having the TV camera 1 as its center of gravity, and (b) shows the light sources 21 to 24 intersecting the optical axis M of the TV camera 1 at a right angle. It is arranged on the horizontal line. If the combination of the light sources that are sequentially turned on is line-symmetrical about the optical axis M (that is, if they are arranged on both sides of the TV camera 1 in between), the number, shape, and arrangement pattern of the light sources can be freely set. Is. For example, each of the light sources 21 to 24 may be a light source such as a spotlight, a linear light source such as a fluorescent lamp or a ring-shaped light source, or a ring-shaped light source arranged coaxially. (Embodiment 2) Another embodiment will be described with reference to FIGS.

In this embodiment, the light sources 21 to 24 are constantly turned on to illuminate the entire pallet 6. The TV camera 1 is moved to the front and back in the horizontal direction, left and right, or both independently of the light source by an actuator (not shown) such as a robot hand. For example, the TV camera 1 is moved forward to obtain the image a, and the TV camera 1 is moved backward to obtain the image b. By doing so, the reflection positions of the light sources 21 to 24 on the surface of the oil film 8 move, so that the reflection images of the light sources 21 to 24 can be removed from the logical product image c.

However, in the present embodiment, the coordinate position of the image frame signal moves in the same direction or in the opposite direction due to the movement of the TV camera 1, so that the entire screen is shifted in the opposite direction, and both image frame signals are shifted. The pixel coordinate positions of the images of the two punching press products (imaging targets) in the pair of images formed by are matched. That is, the same pixel signals of both images a and b are controlled to be input to the AND circuit 33 at the same timing.

In this embodiment, this image shift is performed by adjusting the read timing of the stored image frame signal from the frame memory 32. That is, if the vertical direction, the horizontal direction, and the direction of the image pickup surface of the TV camera 1 at the two image pickup positions match, the TV can be easily read by adjusting the read timing of the stored image frame signal from the frame memory 32. It is possible to match the pixel coordinate positions in the virtual image space of the imaged target as the camera 1 moves.

Further, according to the present embodiment, the logical product of both image frame signals a and b is calculated. If it does in this way, the following effects will also be produced. That is, when binarization is performed so that the background is black (0) and the imaging target is white (1), if the imaging position of the TV camera 1 is different, and the imaging target is a stereoscopic image,
The shape of the upper surface of the imaging target is the same for both image frame signals, but the shape of the imaging target is different for both image frame signals because the side surfaces (wall surfaces) look different. However, in the present embodiment, since the logical product of both image frame signals is obtained, the side surface of the imaging target that becomes a white region at different positions becomes black (0) by the logical product operation and can be removed, so-called parallax. It is possible to eliminate the difference in shape of the imaging target due to.

Also in the present embodiment, the lighting light source at the time of image pickup at each image pickup position can be changed. That is, when the TV camera 1 takes an image at the first imaging position, the lamp group of the first group is turned on, and when the TV camera 2 takes an image at the second imaging position, the lamp group of the second group is turned on. Of course, the first group of lamps and the second group of lamps have different lighting positions. In this way, if the logical product process of both image frame signals a and b is executed for each pixel, in some cases, the unnecessary reflection image input to the TV camera can be removed better. (Embodiment 3) Another embodiment will be described with reference to FIG.

In this embodiment, the AND circuit 33 of FIG.
Comparator 334, analog gate circuits 335, 33
6 and the position of the comparator 31 is changed. The frame memory 32 is an 8-bit (256 gradation) image memory, and an A / D converter (not shown) is provided at its input end and a D / D converter is provided at its output end.
An A converter (not shown) is installed.

The operation of this circuit will be described below. In the same write operation as in the first embodiment, the first image frame signal (image) a having 8-bit brightness information is converted into the frame memory 32.
Then, the TV camera 1 outputs an image frame signal (image) b which is an analog signal, and both images a,
b is sequentially compared by the comparator 334 for each pixel.
When the pixel signal of the image a is large (when it is bright), the comparator 334 outputs a high level to make the analog gate 335 conductive and cut off the analog gate 336. As a result, the pixel signal of the image b, which is the darker pixel signal, is selected.

Similarly, when the pixel signal of the image a is small (when it is dark), the comparator 334 outputs a low level to cut off the analog gate 335 and make the analog gate 336 conductive. As a result, the image a which is the darker pixel signal
Pixel signal of is selected. The signals of both analog gates are binarized by the comparator 31 and output to the circuit 4. With this configuration, the same operational effect as that of the first embodiment can be obtained. (Embodiment 4) Another embodiment will be described with reference to FIGS.

This embodiment is a modification of the second embodiment. Instead of moving the TV camera 1 with the robot hand as described above, one TV is provided at each of the two image pickup positions in advance.
The cameras 1a and 1b are individually arranged. With this configuration, the same effect as that of the second embodiment can be obtained. The operation of the image processing apparatus will be described with reference to FIG. 9. The analog image frame signals output from the TV cameras 1a and 1b are individually binarized by the binarizing circuits 31a and 31b, respectively, and the binarized image is generated. The frame signal a is a binarized image frame signal b delayed by the delay circuit 32a for a predetermined time.
AND circuit 4 performs a logical product process.

The operation of this circuit and the effect itself are the same as those of the second embodiment.
Since it is the same as the above, further description will be omitted. In addition,
In the present embodiment, the delay circuit 32a is a variable delay circuit, and the delay time can be appropriately changed according to the change of the image pickup position of the TV camera 1 or the like. (Embodiment 5) Another embodiment will be described with reference to FIGS.

This embodiment is a modification of the fourth embodiment. Instead of providing two TV cameras 1, one TV camera 1 using a double periscope type mirror device (or prism device) 9. The same signal light as that captured at two image capturing positions is made incident on the left and right of the image capturing surface.
In the mirror device 9, 90 is a prism-shaped barrel.
Reference numerals 91 to 94 are mirrors.

FIG. 11 shows the image pickup surface 100 of the TV camera 1. A mirror 91 is provided on the left half 100L of the imaging surface 100.
The signal light that is incident from is incident on the right half 1 of the imaging surface 100.
Signal light incident from the mirror 93 is incident on 00R. The operation of this image processing apparatus will be described with reference to FIG. The image frame signal output from the TV camera 1 is binarized by the binarization circuit 31 and then delayed by the delay circuit 32 for a predetermined time.
And the binary image frame signal a which is not delayed, and the AND circuit 4 takes the logical product of these binary image frame signals a and b.

The operation and effect of this circuit itself are the same as those of the second embodiment.
Since it is the same as the above, further description will be omitted. (Sixth Embodiment) Another embodiment will be described with reference to FIGS. In this embodiment, a TV camera (imaging unit) 1, four light sources 21 to 24 around it, a timing controller 5 for driving and controlling the light sources 21 to 24, and the TV camera 1
The A / D converter 10 for A / D converting the image frame signal output from the A / D converter and the digital image frame signal output from the A / D converter 10 are stored, signal processed, and a processed image signal is output. It comprises a microcomputer (image signal processing means, threshold level storage means, overall brightness normalization means) 30. The timing controller 5 is controlled by the microcomputer 30, and the TV camera 1 outputs a horizontal synchronizing signal and a vertical synchronizing signal to the microcomputer 30.

The operation of the microcomputer 30 will be described below with reference to FIGS.
This will be described with reference to the flowchart of FIG. First, when the power is turned on, the initial setting operation of each unit is performed (100), and it is checked whether or not an image pickup command is input from the outside (102).
It waits until it is input, and if it is input, the first and second light sources 21, 22 arranged on both sides of the TV camera 1 are turned on (104), and the illuminance is changed from the turn-on command in step 104. After a predetermined period of stabilization (105), the first image frame signal S1 which is a digital image signal of one frame is read from the TV camera 1 in synchronization with the vertical sync signal and stored in the first frame memory (106), ,
The second light sources 21 and 22 are turned off (107).

Next, the third and fourth light sources 23 and 24 arranged on both sides of the TV camera 1 are turned on (108), and a predetermined time after the illumination is stabilized from the turn-on command of this step 108 (109). ), TV in sync with the vertical sync signal
The second which is a digital image signal of one frame from the camera 1
The image frame signal S2 is read and stored in the second frame memory (110), and the third and fourth light sources 23 and 24 are turned off (112). The light sources 23 and 24 are arranged at right angles to the light sources 21 and 22 with the camera optical axis as the center.

Here, the microcomputer 30 has a built-in first threshold value memory, and this first threshold value memory is used for binarizing the above-mentioned first image frame signal S1 for each pixel. It is assumed that the 1 threshold signal VtS1 is stored. Next, the pixel signal S1PCi at the address i of the first image frame signal S1 is read from the first frame memory,
In synchronization with this, the pixel signal VtS1i at the address i of the first threshold signal VtS1 is read from the first threshold memory,
The size of both is compared (200). Note that i is initially 0
It has been.

If S1PCi is larger than VtS1i, 1 is stored in the address i of the first binary image memory (2
02), and proceeds to step 206. S in step 200
If 1PCi is not larger than VtS1i, 0 is stored in the i-th address of the first binary image memory (203), and the routine proceeds to step 206. In step 206, 1 is added to the number of addresses i, and then it is checked whether i is the final address of the imaging region (first binary image memory) (208), and if not so, the process returns to step 200. If i is the final address of the imaging area, i is reset to 0 (210) and the process proceeds to step 212.

Next, the pixel signal S2PCi at the i-th address of the second image frame signal S2 is read from the second frame memory, and in synchronization with this, the pixel signal VtS2i at the i-th address of the second threshold value signal VtS2 is set to the second threshold. It is read from the value memory and the magnitudes of the both are compared (212). If S2PCi
Is larger than VtS2i, 1 is stored in the i-th address of the second binary image memory (214), and the routine proceeds to step 218. If S2PCi is not larger than VtS2i in step 212, 0 is stored in the address i of the second binary image memory (215), and the process proceeds to step 218.

At step 218, 1 is added to the address number i,
Then, it is checked whether i is the final address of the imaging area (second binary image memory) (220), and if not, the process returns to step 212. If i is the final address of the imaging area, i is reset to 0 (222), and step 40
Go to 0. Hereinafter, the first binarized image frame signal stored in the first binary image memory will be referred to as S1 ′, the value of the i address thereof will be referred to as S1PCi ′, and the first binary image frame signal stored in the second binary image memory will be referred to as S1 ′. The binary image frame signal is called S2 ',
The value of the i-th address is called S2PCi '.

In step 400, the first binarized image frame signal S1PCi 'at the i-th address and the second binarized image frame signal S2PCi' at the i-th address which are binarized by the above-described routines with a suitable reflected light amount are used. Of S1PCi 'and S2PCi' are 1
If it is (white), 1 is assigned to the i-th address of the first binarized image memory.
Is written (402), 1 is added to the count value N of the built-in white counter for counting the number of accumulated white addresses, and the process proceeds to step 406. If both S1PCi 'and S2PCi' are 1 (white), the first 0 is written to the address i of the binarized image memory of (404), 1 is added to i (406), and i
Is checked to see if it is the final address iend (408). If not, the process returns to step 400, and if not, the process proceeds to step 300.

In step 300, it is checked whether or not the cumulative number of white addresses N is within a suitable range (Nmin <N <Nmax) stored in advance. If N is equal to or less than the predetermined minimum value Nmin, the threshold value is set. It is judged to be unsuitable because it is high overall (the amount of reflected light is too small overall), and the process proceeds to step 302. Steps 302 to 308 are the first threshold signal VtS1 and the second threshold signal VtS1 stored in the memory for storing the threshold value.
Pixel signals VtS1i of all addresses of the threshold signal VtS2,
This is a routine for reducing VtS2i (i = 0 to iend) by a small constant value ΔVt. First, two pixel signals VtS1 and iVtS2i at the address i are respectively Δ.
Vt is subtracted (302), 1 is added to i (304), i
Has reached iend (306). If it has not reached iend, the process returns to step 302. If it has reached iend, i is reset to 0 (308) and the process returns to step 200.

If N is greater than or equal to the predetermined maximum value Nmax in step 300, the threshold value is low overall (the amount of reflected light is too large overall), and it is determined to be inappropriate and step 3
Proceed to 12. The steps 312 to 318 have essentially the same routine structure as the steps 302 to 308 described above, and the first threshold signal VtS1 and the second threshold signal V
Pixel signals VtS1i and VtS2i (i of all addresses of tS2
= 0 to iend) is a routine for increasing each by a small constant value ΔVt, and therefore further description will be omitted.

Further, if N is within the above range in step 300, the routine is ended. As a result, since the light and dark image binarized by the optimum threshold value for each pixel is used in the third binarized image memory to remove the scale, an accurate work shape can be obtained.

[Brief description of drawings]

FIG. 1 is a side view illustrating a main part of an image processing apparatus according to a first exemplary embodiment.

FIG. 2 is a layout diagram of light sources used in the image processing apparatus of FIG.

FIG. 3 is a block diagram of the image processing apparatus in FIG.

FIG. 4 is an explanatory diagram illustrating image processing according to the first embodiment.

5 is an arrangement diagram showing a modified example of the arrangement of light sources in FIG.

FIG. 6 is a perspective view showing a main part of an image processing apparatus according to a second embodiment.

FIG. 7 is a logic circuit diagram showing a main part of the third embodiment.

FIG. 8 is a front view showing a main part of an image processing apparatus according to a fourth embodiment.

FIG. 9 is a block circuit diagram showing a main part of the fourth embodiment.

FIG. 10 is a partially cutaway front view showing a main part of an image processing apparatus according to a fifth embodiment.

FIG. 11 is a diagram illustrating an image pickup surface of a TV camera 1 according to a fifth embodiment.

FIG. 12 is a block circuit diagram showing a main part of a fifth embodiment.

FIG. 13 is a block circuit diagram showing a sixth embodiment.

14 is a flowchart showing the operation of the circuit of FIG.

15 is a flowchart showing the operation of the circuit of FIG.

16 is a flowchart showing the operation of the circuit of FIG.

17 is a flowchart showing the operation of the circuit of FIG.

[Description of Reference Signs] 1 is a TV camera (imaging means) 21 to 24 is a light source, 3 is an image signal processing circuit (image signal processing means), 5 is a timing controller (control means), and 7 is a punched product (imaging target) Is.

Claims (15)

[Claims] 1. A plurality of light sources for illuminating an imaging target from different directions, lighting control means for individually controlling lighting of each light source, and a plurality of image frame signals obtained by sequentially imaging the imaging target. In an image processing device comprising an image pickup means for outputting and an image signal processing means for applying a predetermined image signal processing to each of the image frame signals, the image pickup means sequentially picks up the image pickup target under different lighting conditions of the respective light sources. The image signal processing unit outputs an image of each of the image frame signals, and the image signal processing unit includes a logical operation unit that sequentially performs a logical operation of each pixel signal of the plurality of image frame signals for each same pixel position. An image processing device characterized by: 2. An image pickup means for outputting a plurality of images respectively obtained by picking up the same image pickup target from a plurality of different image pickup positions as image frame signals, and each of the images between the respective images due to the displacement of the image pickup positions. An image pickup target alignment unit that corrects a displacement of a coordinate position of the image pickup target, and a logical operation unit that sequentially executes a logical operation of each pixel signal of the displacement corrected image frame signals for each same pixel position. An image processing device characterized by the above. 3. The image processing apparatus according to claim 2, wherein the logical operation means has a logical product circuit for performing a logical product operation of the displacement-corrected image frame signals. 4. The image pickup means includes a TV camera and the TV.
The image processing apparatus according to claim 2, further comprising a moving unit that moves a camera between the image capturing positions. 5. The image processing apparatus according to claim 2, wherein the image pickup means includes a plurality of TV cameras individually arranged at the plurality of different image pickup positions. 6. The image pickup means is a T arranged at a predetermined position.
The image processing apparatus according to claim 2, further comprising a V camera and a signal light switching unit that sequentially inputs light introduced from the plurality of different image pickup positions to the TV camera. 7. The image processing apparatus according to claim 1, wherein the logical operation means includes an AND circuit. 8. The logical operation means has a circuit for selecting a signal at a lower level among pixel signals output a plurality of times from the same pixel of the image pickup means under different illumination conditions. Alternatively, the image processing device according to item 2. 9. The image according to claim 1, wherein the lighting control means turns on the light sources, which are at least a pair of light sources arranged on both sides of the imaging means, in the same imaging frame period. Processing equipment. 10. An image pickup means fixed to the tip of a robot hand and sequentially outputting first and second image frame signals obtained by picking up an image of an object to be imaged in first and second image pickup periods, respectively. First and second light sources that are fixed to the tip of the robot hand and illuminate the imaging target while being close to both sides of the imaging unit
Light source, and third and fourth light sources that are fixed to the tip of the robot hand and illuminate the imaging target while being close to both sides of the imaging means at different parts from the first and second light sources. And turning on the first and second light sources and turning off the third and fourth light sources during the first imaging period, and turning on the third and fourth light sources during the second imaging period And lighting control means for turning off the first and second light sources, and image signal processing means for binarizing the first and second image frame signals pixel by pixel and then performing a logical product operation for each pixel. An image processing apparatus comprising: 11. An image pickup means fixed to the tip of the robot hand to sequentially output image frame signals obtained by sequentially picking up images of an image pickup target, and fixed to the tip of the robot hand while being close to the image pickup means. In the image processing device, a light source for illuminating the imaging target and an image signal processing unit for binarizing the image frame signal at a predetermined threshold level for each pixel, wherein the image signal processing unit is Threshold value storage means for individually storing the threshold level for each or a predetermined area composed of a plurality of pixels, the threshold level read from the threshold level storage means, and An image processing apparatus comprising: a binarizing unit that compares an image frame signal with each pixel. 12. An image pickup means fixed to the tip of a robot hand and sequentially outputting first and second image frame signals obtained by picking up an image of an image pickup target in first and second image pickup periods, respectively. A first light source that is fixed to a distal end of the robot hand and illuminates the imaging target while being close to the imaging unit; and the robot that is close to the imaging unit at a portion different from the first light source. A second light source that is fixed to the tip of the hand and illuminates the imaging target; a second light source that turns on the first light source and turns off the second light source during the first imaging period; Lighting control means for turning on the second light source and turning off the first light source during a period, and after binarizing the first and second image frame signals for each pixel at a predetermined threshold level , An image signal processing means for performing a logical product operation for each pixel The image processing device is characterized in that the image signal processing means binarizes signals of the same pixel of the both image frame signals at different threshold levels. 13. An image pickup means fixed to the tip of a robot hand and sequentially outputting first and second image frame signals obtained by picking up an image of an image pickup target in first and second image pickup periods, respectively. A first light source that is fixed to a distal end of the robot hand and illuminates the imaging target while being close to the imaging unit; and the robot that is close to the imaging unit at a portion different from the first light source. A second light source that is fixed to the tip of the hand and illuminates the imaging target; a second light source that turns on the first light source and turns off the second light source during the first imaging period; Lighting control means for turning on the second light source and turning off the first light source during a period, and after binarizing the first and second image frame signals for each pixel at a predetermined threshold level , An image signal processing means for performing a logical product operation for each pixel The image signal processing means extracts a state quantity related to an average signal level of the entire image frame signal, and the number of white pixels in the binarized image frame signal approaches a predetermined reference number. An image processing apparatus comprising: an overall brightness adjusting unit that shifts the threshold level of each pixel by the same amount in the direction based on the state quantity. 14. The image signal processing means extracts the number of white pixels in the binarized image frame signal as the state quantity, and the number of white pixels approaches a predetermined reference number. 14. The image processing apparatus according to claim 13, wherein the threshold level for each pixel is shifted by the same amount. 15. An image processing apparatus comprising all the constituent elements according to claims 10 to 13.