JPH0580874B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention generally relates to analogous discrimination of image signals, that is, image signals, and in particular, by comparing an image signal to be discriminated, that is, a comparison image signal, with various reference image signals to be compared, or By comparing the comparison image signal with the reference image signal to be compared, it is determined which of the various reference image signals the comparison image signal is most similar to, or to which of the various reference image signals the reference image signal is most similar. This invention relates to a device that determines which of the comparison image signals is most similar and switches the circuit to that image signal. In particular, when a perfectly circular image signal is used as a reference image signal, different image signals such as triangles and squares are used as comparative image signals to be compared with the perfectly circular image signal, and the square image signal has a higher degree of similarity ( Degree of coincidence)
The present invention relates to an image similarity determination and selection device that can determine and select which of completely different images is more similar (coinciding) with its reference image signal, such as selecting a square based on a higher image signal.

[Conventional technology]

There are various methods for determining whether the appearance of a certain object is the same as that of another object. Among these methods, a method is often used in which the object is represented in an image as an image signal, recognition is performed to determine whether the two images match, and then similarity is determined between the two images. In addition, to determine the image shift, either the reference image signal or the comparison image signal is passed through multiple delay circuits, and the other is passed through a 1/2 time delay circuit of the multiple delay circuits. There is also a device that determines the amount of deviation by determining at which position in the plurality of delay circuits the values match within the allowable range.

[Problems to be solved by the invention]

In this case, the conventional method has been to multiply the image signals of both images by an electronic computer, but this is not only extremely costly, but also takes time to determine whether they are similar or not. became even more costly. Accordingly, in the present invention, when the same object or different objects are photographed as image signals, the signal with the highest similarity is selected from among a plurality of reference images, and the coincidence of both image signals is determined. To simplify the explanation, the principle of operation will be explained using an operation related to positional deviation as an example.
The positions in the image signals of the image and the second image are
If there is a shift in the front, back, top, bottom, left, right, or rotational direction, it is extremely difficult to determine that they are the same object. However, this is because the positional shift of an image appears as a time shift of the image signal, and it is impossible to determine whether or not the two image signals are the same unless the two image signals match in time. Furthermore, if there is a positional shift between two identical images, it is impossible to determine the position unless the two images are corrected to the same position in each image signal, so this must be corrected. However, if this "displacement" is made mechanically as a spatial thing, it will not be possible to follow objects that move quickly in terms of speed. Of course, even if it is assumed that the distance and direction of the imaging device can be moved quickly, the afterimage will set its limits. Therefore, there are many demands for matching objects. For example, there are various issues such as whether the parts of the product are installed correctly, whether the characters printed on the IC etc. are printed correctly, and even whether the seal stamped on the document is genuine or not. . especially,
In the case of fine shapes, it is easy for the human eye to make mistakes and it is physically impossible to continue for a long time. In particular, temporal tracking is a problem when it comes to identifying products that are being sent one after another on a belt conveyor or the like. Therefore, as described above, a method for comparing not only the positional shift of images but also the similarity of various images can be considered. For example, when selecting a required part from among various parts, an image of the required part is stored in the storage means as a reference image signal. Therefore, images of the various parts are sequentially projected, and this image signal to be determined is sequentially compared with the above-mentioned reference signal to determine which of the first comparison image signal and the second comparison image signal is closer to the reference image signal. Have them make a judgment and choose the one that is more similar. and,
This is further compared with a third comparison image signal.
By repeating this process, the target part is selected from among those parts. There is also a need for an apparatus that compares completely different images to a reference image and determines which one is more similar to the reference image and selects one. For example, you can compare the completeness of images in a computer game, or make various comparative judgments (contamination rate, diffusion rate, removal rate,
However, with conventional devices, it has been impossible to compare and determine the irregularity of these images. Furthermore, it was possible to determine similarity within the range of images that were close to similar, but when a circular or reference image was used and a completely different triangular or quadrilateral image was compared, both were treated as dissimilar, resulting in a special problem. Application to other fields was not possible.

[Means to solve the problem]

In the present invention, the appearance of a certain object is first converted into an image signal by using an imaging device, and for example, to easily explain the case of spatial or positional deviation of the object, this is expressed as a temporal deviation of the image signal. This was resolved as a discrepancy. That is, for example, first, the appearance of a reference object is converted into an image signal,
This is passed through multiple delay circuits, each with a slightly different time constant. Therefore, the respective outputs taken out from the respective delay circuits are slightly shifted in time. In this way, a plurality of reference image signals are created, stored in the storage means, and compared one after another with the image signals from the object to be discriminated.
If it is possible to determine which of the image reference signals is closest to the image signal output from the delay circuit and switch to that signal, the time difference will be instantly corrected. As mentioned above, it is possible to search for not only the positional deviation but also the object in the image that the user desires to select. In this way, both of these image signals, for example, a reference image signal such as an image signal of a filled-in circular shape, and an image signal of a filled-in triangle, square, hexagon, oval, perfect circle, or any other shape or pattern. Rather than sequentially comparing comparison image signals such as , etc. with a reference image signal, by determining and selecting which of the two comparison image signals has a higher degree of coincidence with the reference image signal, centering on the reference image signal, The degree of coincidence between the two image signals, that is, the degree of coincidence between the two objects can be determined, and it is possible to determine whether they are similar or not (high degree of coincidence). However, in the second invention, if the similarity is not set as the reference value even when compared with the closest comparison image signal, it is determined that the signal is dissimilar. become. The specific configuration of the image signal comparison and selection device according to the present invention will be described below. First, to describe the first invention, first, a reference image signal, such as a perfectly circular image signal with a filled inside, and a signal to be compared with the reference image signal, such as a triangle, square, hexagon, or ellipse with a filled inside. There are comparison image signals such as image signals of circular shapes, circular shapes, and other shapes/patterns. This reference image signal or the above-mentioned comparison image signal is composed of a plurality of signals. Next, there is a storage device that stores the reference image signal or the comparison image signal. and,
A first image signal that compares the image signal stored in the storage device with the other signal and is one of the plurality of signals and the single image signal. There is a comparator. Furthermore, there is a second comparator that similarly compares a second image signal, which is another one of the plurality of image signals, with the single image signal. Then, there is a comparison switch that compares the output signals from the first comparator and the second comparator to determine similarity and selects the same signal or one that is more similar. Furthermore, the first comparator, the second comparator, and the comparison switcher are considered as one block, and a plurality of blocks are provided, and a plurality of selection means are provided for sequentially comparing and selecting the more similar one. be. Next, the second invention includes the configuration of the first invention, plus a discrimination comparison for comparing the image signal selected by the apparatus of the first invention with a discrimination image signal to discriminate whether the images match or do not match. It is a vessel.

[Effect]

The image signal switching system configured as described above operates as follows. First, in the first invention, the second and third signals are each compared with the first signal, and the output of the closer one is extracted. If there is a plurality of third signals, the number increases to the fourth, fifth, and so on. In other words, for example, to explain in terms of positional deviations, the reference signal is passed through various delay circuits and t ₁ , t ₂ , t ₃ , ... t _o
The time-delayed signals B ₁ , B ₂ , B ₃ , . . . B _o are extracted. And do this first, for example:
Image signals having adjacent delay times such as B ₁ and B ₂ are compared with a comparison image signal that is an image signal from an object whose similarity is required to be determined.
In other words, this comparison image signal is tentatively compared with the delayed reference image signal _B1 signal. At the same time, this comparison image signal is compared with the adjacent delayed reference image signal _B2 . Then, each comparative image signal is taken out, a comparator determines which signal is closer, and a switch linked thereto shifts to the next delayed signal. For example, in the above example, if it is determined that B ₂ is closer, the circuit moves on to compare B 2 with B ₃ , which is adjacent to B ₂ . Therefore, a comparison between B ₂ and B ₃ is made here, and this is repeated to arrive at the signal with the closest delay time. In the above case, if the comparison image signal is also delayed by about 1/2 time _t4 , the relative delay of the time shift can be determined. Although the above delay circuits may each be provided in parallel, it is more economical to connect the delay circuits in series and provide a tap at each point. It goes without saying that the reference signal and comparison image signal in the above example may be reversed to perform comparison and discrimination. Of course, this works in exactly the same way not only for the positional shift but also for the similarity judgment and selection of various images.

【Example】

An image signal selection device according to the present invention will be described in detail below with reference to an embodiment thereof and the accompanying drawings showing the same. FIG. 1 shows a part of a circuit diagram used in an embodiment of the image signal selection device according to the present invention. First, we will explain the positional shift of the image to make it easier to understand. Since it is impossible to advance the time of the image signal, the comparison image signal and/or the reference image signal are delayed through a delay circuit, and the first signal and the second signal are separated by a time difference between the two signals. Signal. Then, the second signal is further delayed by passing through another delay circuit to produce a delayed amplified signal having a time difference from the second signal. In this case, the number of other delay circuits that further delay the second signal may be one, or may be a plurality of delay circuits with time differences. If there is only one signal, the delayed increased signal from there is set as the third signal, and the third signal and the second signal are each compared with the first signal. Then, the two output signals are further compared to determine which of the second signal and the third signal is closer to the first signal. Based on this, the image signal selection device automatically operates the switching device instructed by the comparator and extracts the output of the signal with the smaller time difference. If there are multiple delay circuits, a plurality of delayed image signals with time differences are extracted, so each of them is compared with the first signal as described above, and the output signal is further added to the first signal. The signal is compared with the first signal as follows, and this process is repeated until it is determined which signal is closest to the first signal. Now, as described above, the output of the signal with the smallest time difference is extracted. By the way, in the latter case, if a central time is provided, the result will be as follows. That is, as described above, outputs of each delay whose delay time is gradually increased are extracted from a plurality of delay circuits each having a time difference. Then, a signal near the midpoint between the undelayed signal and the most delayed signal is set as the center time signal, and the comparison image signals of relatively delayed time are arranged around the center time signal. As described above, each of the image signals having adjacent delay times and the corresponding image signal are successively compared by the comparator. Next, the second invention will be described. Since this includes all of the first invention, all of the above description is incorporated. Then, the final output image signals output as described above are compared by another comparator to determine whether they match or do not match. This will be explained in more detail below. First, a reference signal is provided. This is done by taking an image of the appearance of the object to be determined using an imaging device, creating an image signal, and directly taking it out, or by recording it in a storage device or the like and taking it out. Of course, depending on the image to be discriminated, this reference signal may be generated by an electric computer. That is, the method of acquiring the image signal is not limited as long as it is an image signal from which a reference image can be obtained. By passing this reference signal through delay means such as a delay circuit, two image signals B1 and B2 with a time lag are generated. Then, the signals B1 and B2 with the time lag are compared with the comparison image signal J in comparators 1 and 2, respectively, and further, this output signal is compared in comparator 3, and the output signal is also compared with the comparison image signal J. , switches the switch S. This switch S may be mechanical or electronic. However, this switching of image signals is performed by switching to the closer signal when the comparator 3 determines which of the signals Bn and B2 with a time lag of the above-mentioned reference signal is closer. It must be configured so that it can be connected to a circuit. Using the above circuit as one block, the output signal from the switch S is compared with the next signal. This "next signal" is a signal B3 which has a further time lag from the signals B1 and B2 which have a time lag from the above reference signal (although it is possible to combine them freely, the circuit configuration is complicated). become). In the same way, if you create the necessary number of signals with the time lag gradually increasing, compare them one after another, and switch the signal to the one that is closer, all of the switching devices will be able to use the above comparison image signal. In contrast, the reference signal with the closest delay time is switched to, and its output signal can be extracted last. Note that this delay time with a slight difference is
B ₁ , B ₂ , B ₃ . . . of the series delay circuit as shown in Fig. 2.
It is best to take it out from the B _o tap. The above is an example in which the reference time is shifted, but in contrast to the above example, the comparative image signal J
may be delayed one after the other. Of course, it is better to delay both of them, but in that case, one signal will create many signals with slightly shifted delay times, and the other will have a delay time that is about half the slowest among the many signals above. It is best to use a delay time of . This allows for the relative slowing down of time. In addition, the comparison of B ₁ to B _o of the signals with slightly different delay times and the switching of all signals are as follows.
For example, one method compares signals B ₁ and B ₂ , then compares the output signal of the switch S with the third signal B ₃ , and sequentially compares them up to signal B _o , and the other method compares all of the adjacent signals. For example, all signals such as B ₁ and B ₂ and B ₃ and B ₄ are compared simultaneously, and the output signal from each switch is compared simultaneously with the blocks adjacent to each block. There is a method of switching a switch and extracting the final output. In either case, since the blocks of the comparison switching circuit shown in Fig. 1 are simply stacked,
The circuit can be simplified, which helps reduce costs and save labor in manufacturing. Similarly, as shown in the circuit diagram of FIG. 2, the delay circuit can be stacked into single blocks, contributing to cost reduction and manufacturing labor savings. On the other hand, a case where the image signal selection device according to the present invention is applied to a completely different image will be described with reference to FIG. FIG. 3 is an explanation showing comparison and judgment of completely different images. There is a reference image signal J that is a perfect circle with a filled inside. Next, there is a first comparison image signal B1 in the form of a filled triangle. Therefore, this reference image signal J and the first comparative image signal B1 are compared by the first comparator 1. On the other hand, the square second comparison image signal B
There are 2. This is also compared with the reference signal J in the second comparator 2. Then, the third comparator 3 compares the degree of coincidence between the images from the first and second comparators 1 and 2 (the shaded area in Figure 3), and which image is better for the reference. Determine whether it is closer to the image. Then, the comparison image signal of the closer image (i.e., square image B
2) issues a command to switch the switch S, and sends the comparison image signal to the next block. In other words, rather than sequentially comparing one comparison image signal and its reference image signal to determine similarity, one comparison image signal and its reference image signal are compared to determine which of the two comparison image signals corresponds to the reference image signal. The selection is made by determining whether the degree of coincidence with the signal is high, and these steps are performed in sequence. Similarly, this is compared sequentially or in parallel with comparison image signals B3, B4, B5, and B6, and the image with the higher degree of similarity is selected. As mentioned above, in the past, it was not possible to determine which of the above-mentioned triangles and quadrilaterals was more similar to the circular reference image signal.
Regarding the relationship between B5 and B6, it was not possible to determine which one is closer to the reference image signal. The present invention accomplishes this impossible point. Furthermore, if the comparison signals are arranged in an orderly manner like a delay circuit for positional deviation, the similarity can be easily selected using conventional equipment, but as shown in Figure 3, the object to be compared is of an unusual shape and the comparison When the order of the shapes is also random, it is not possible to select which shape among them has the highest degree of matching with the reference shape. The present invention also solves this problem. 4. Effects of the Invention As described above, the image signal selection device according to the present invention automatically sequentially compares a large number of image signals, automatically selects the one that is more similar to the reference image, and achieves the purpose. It allows you to instantly reach the desired object. In particular, when selecting an image with no positional shift, the process can be simplified because the image pickup device is not moved to align the images. Furthermore, it became possible to use a combination of block circuits, reducing costs and greatly contributing to labor savings in circuit manufacturing. The main advantage is that the speed of discrimination has been greatly improved, and the circuit has become extremely simple, making it even more effective in discrimination than ever before. In particular, it has become possible to instantly compare two images and select from among a large number of images the one closest to the reference image signal. In addition, the second invention, which can simultaneously determine whether the images match or do not match, has a great effect. Furthermore, it has become possible to judge the degree of matching between completely different figures.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of one block of an embodiment of a portion of a comparison switching circuit used in an image signal selection device according to the present invention. FIG. 2 is a circuit diagram of one embodiment of the delay circuit. FIG. 3 is an explanatory diagram showing comparison and judgment of completely different images, and a to f are plan views for comparison of respective figures. 1, 2, 3... Comparator, B ₁ , B ₂ , B ₃ , _Bo ...
Delayed reference image signal of time shift, J...comparison image signal, S...switcher.

Claims (1)

[Scope of Claims] 1. A reference image signal and a comparison image signal to be compared with the reference image signal, which includes a plurality of the reference image signals or the comparison image signals, the reference image signal or the comparison image. A storage device that stores signals; a first image signal that is one of the plurality of signals that compares the image signal stored by the storage device with another signal; and the single image described above. A first comparator that compares the image signal with the image signal, and a second comparator that is another one of the plurality of image signals described above.
A second comparator that compares the image signal of the image signal with the above-mentioned single image signal, and compares the output signals from the first comparator and the second comparator and makes an analogy judgment to determine whether they are the same or similar. A comparison switcher to select, the first comparator and second comparator, and the comparison switcher described above are set as one block, and a plurality of blocks are provided to sequentially compare and select more similar ones. An image signal selection device comprising: means. 2. A reference image signal and a comparison image signal to be compared with the reference image signal, which includes a plurality of the reference image signals or the comparison image signals, and a storage device that stores the reference image signal or the comparison image signal. , a first image signal for comparing the image signal stored in the storage device with another signal, which is one of the plurality of signals, and the single image signal. 1 comparator, and a second comparator which is also another one of the plurality of image signals described above.
A second comparator that compares the image signal of the image signal with the above-mentioned single image signal, and compares the output signals from the first comparator and the second comparator and makes an analogy judgment to determine whether they are the same or similar. A comparison switcher to select, the first comparator and second comparator, and the comparison switcher described above are set as one block, and a plurality of blocks are provided to sequentially compare and select more similar ones. and a discriminating comparator for comparing the image signal selected as described above with a discriminating image signal and discriminating whether the images match or do not match. 3. The image signal selection device according to claim 1 or 2, wherein the plurality of image signals are obtained by capturing a plurality of separate images by an imaging device. 4. Claim 1 or 2, characterized in that the plurality of image signals are one image captured by an imaging device and converted into a plurality of image signals with time differences by a delay circuit. image signal selection device.