JPH05273144A - Image processor - Google Patents

Abstract

PURPOSE:To provide an image processor using the surface inspecting method capable of physically detecting a surface flaw on the surface of a specimen at a high speed. CONSTITUTION:An image processor quantization-processing the surface image of a specimen 14 obtained by exposing and scanning the surface of the specimen 14 is linearly arranged with many shutter elements closed normally, opened when more than preset quantity of light is received, and having a small area, it is provided with an image extracting means 8 arranged on the passing passage of the light from the specimen 14, and it is also provided with a quantization processing means 13 arranged to face the shutter elements of the image extracting means 8, linearly arranged with many quantizing elements receiving the light passing through the shutter elements, outputting the quantized signal in response to the light quantity, and having a small area and provided behind the image extracting means 8 in the advance direction of the light from the specimen 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanner for two-dimensionally scanning the surface of an object such as iron, non-ferrous metal, synthetic resin, glass and semiconductor, and the reflected light measured from the surface of the object. On the basis of the above, the present invention relates to an image processing device for cutting out and quantizing an optically detected image on the surface of an optical specimen, and in particular, it is possible to cut out the optically detected image at high speed and perform a quantizing process. The present invention relates to an image processing device.

[0002]

2. Description of the Related Art Conventionally, as a surface inspection apparatus to which this type of image processing apparatus is applied, for example, the 34th System Control Information Society Research Presentation Lecture Proceedings (ISCIE, pp. 103 to 104, '90- Examples include the device disclosed in 5). The surface inspection apparatus 1 _a disclosed above is shown in FIG. According to the surface inspection apparatus 1 _a shown in FIG.
Laser light or white light from a light source is applied to the surface of the running object such as a steel plate, and the reflected light from the surface of the object is received by a light receiving unit that sequentially scans each pixel in the main scanning direction. The strength is converted into an electric signal according to the strength and output. Then, as shown in FIG. 6, the image processing unit, based on the electric signal for each image from the image sensor unit, uses 0 (white pixel) or 1 (hatched) for each pixel using, for example, a certain threshold value. Pixel), and a two-dimensional quantized image binarized into the values of Then, based on this quantized image, a defect image which is regarded as a flaw or a defect on the surface of the subject is cut out, and the cut out defect image, for example, the length h, the width w, the area, etc. Extract feature quantities. Subsequently, the determination unit determines the types of flaws and defects on the surface of the subject and their grades based on the feature amount of the defect image from the image processing unit. In the determination unit, for example, a back-propagation weight learning type, a so-called back propagation type neural network is used to perform the determination as described above, and learning prepared in advance corresponding to the various feature amounts is performed. The feature amount related to the defect image calculated by the image processing unit is input as data to the neural network that has been learned from the input data for calculation.
Such a surface inspection apparatus has an advantage that the calculation in the determination unit can be performed at high speed. In the above-mentioned conventional example, the cutout process is performed after the quantization process, but it is naturally possible to perform the reverse process. In the present invention, either of them can be performed first.

[0003]

In [0006] the conventional surface inspection apparatus as described above 1 _a, when the image processing unit is a two-dimensional quantized image is created, the for all the pixels for each individual pixel It is necessary to apply threshold processing and perform quantization (binarization) processing. In addition, when the defect image is cut out from the entire two-dimensional quantized image, the contour (edge line) of the defect image is obtained to specify the defect image, so that all pixels are adjacent to each other. It has been necessary to compare the binarized data for each individual pixel. As described above, performing the quantization process or the defect image cutout process for all the pixels requires a large amount of calculation time in the image processing unit, and in particular, the surface of the subject running at a high speed. It is hard to say that it is an appropriate method when trying to accurately inspect. On the other hand,
In order to improve the image processing function such as improving the resolution of the image when the size of the entire quantized image is constant, or widening the entire quantized image when the size of the pixel is constant. In that case, the number of pixels to be calculated must be increased. In such a case, the conventional apparatus has a problem that the calculation in the image processing unit takes much longer. The present invention has been made in view of the above conventional problems, and is used for a surface inspection method capable of speeding up detection of a physically detected state such as a surface defect of a surface of a subject. It is an object of the present invention to provide an image processing device capable of performing the above.

[0004]

In order to achieve the above object, the main means adopted by the present invention is the gist of the present invention, in which a subject surface image obtained by exposing and scanning the subject surface is quantized. In the image processing apparatus, an image cutting-out means provided in a passage path of a light beam from a subject, in which a large number of shutter elements having a small area which are normally closed and open by receiving a light of a predetermined light amount or more are arranged linearly When,
A large number of linear quantizing elements are provided corresponding to the shutter elements of the image clipping means and receive the light passing through the shutter elements and output a quantized signal according to the amount of light. In addition, the image processing apparatus comprises a quantization processing unit provided behind the image cutting unit as viewed in the traveling direction of the light beam from the subject.
It should be noted that the shutter element, the image cutting-out means, the quantizing element and the quantizing processing means in the present invention are not limited to the constitutions shown in the embodiments described below, but include all constitutions for achieving the above respective functions.

[0005]

When the shutter element is exposed to a predetermined amount of light or more from the subject, the shutter element opens and the quantizing element arranged behind the shutter element is exposed. When the amount of light hitting the quantizing element is equal to or larger than a predetermined value, the element outputs a quantized signal. Since the plurality of quantizing elements are arranged in a plane, the quantized signal group represents a quantized image of the surface of the subject. In this device, it is not necessary to scan the drive voltage to each element, which is usually performed, and the image is cut out and quantized at the moment when the light from the surface of the object is incident on the shutter element in the image cutout means. It is possible to perform processing, and an image processing device with extremely high speed operation can be realized.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. In addition, the following embodiments are examples of embodying the present invention and are not intended to limit the technical scope of the present invention. Further, although the following embodiments relate to image detection of a two-dimensional surface, the present invention is naturally applicable to one-dimensional detection. Here, FIG. 1 shows an image cropping device 8 which is a component of an image processing device A according to an embodiment of the present invention.
2 is a wiring block diagram showing the quantization processing device 13 which is a component of the image processing device A according to the embodiment of the present invention.
3 is a schematic block diagram showing a state in which a surface defect image or the like on the surface of a subject is cut out and quantized by using the image processing device, and FIG. 4 shows a relationship between the surface defect image and the image processing device. It is a top view shown.

As shown in FIG. 1, the image processing apparatus A according to the present embodiment comprises, in series, a light receiving element 2 _a whose electric resistance changes by receiving light and a light modulation element 3 whose light transmittance changes by an applied voltage. position sensing element formed by connecting to 4 _a and, made of a light modulation element 3 formed by connecting a plurality series shape recognition device 5 for light transmittance is changed by the applied voltage, the position detecting element 4 _a and the A plurality of image cutting elements 6 configured by connecting the shape recognition element 5 in series are connected in parallel,
An image clipping device 8 including a circuit in which adjacent connection points of the position detecting element 4 _a and the shape recognizing element 5 are connected to each other by a wiring having a resistor 7, and a light receiving device whose electric resistance changes by light receiving A quantizing circuit 11 constituted by connecting in parallel a quantizing element 10 in which an element 2 _b and a light emitting element 9 which emits light by an applied voltage of a certain threshold value or more are connected in parallel, and an electric resistance by light reception A position detecting circuit 12 constituted by connecting position detecting elements 4 _b composed of variable light receiving elements 2 _b in parallel is provided with a quantization processing device 13 formed by connecting in series, and as shown in FIG. The image cutout device 8 is installed directly above the subject 14, and the quantization processing device 13 is installed thereon. The specular reflection light of the light from the exposure scanner L on the surface of the subject 14 is cut out from the image. Device 8 and the above quantization processing Not incident on the location 13, only diffusely reflected light at the abnormal portion when the abnormal portion in the subject 14 surface exist, the image clipping unit 8 and the quantization processing apparatus 1
The position of the image processing device A having the image cutting device 8 and the quantization processing device 13 is determined so that the image processing device A enters the image processing device 3.

[0008] In this embodiment, the position sensing element 4 _a of the image clipping device 8 is provided 100, the light modulation device 3 of shape recognition element 5 is formed by four 100 columns. Further, 100 position detecting elements _4b were provided in the quantization processing device 13, and 100 rows of 4 quantizing elements 10 were formed.
The image cutout element 6 corresponds to the shutter element of the present invention, the image cutout device 8 corresponds to the image cutout means, the position detection circuit 12 corresponds to the quantization element, and the quantization processing device 13 corresponds to the quantization processing means. Then, the position detection elements 4 _b in the quantization processing device 13 are arranged so as to be directly above the light modulation elements 3 in the position detection elements 4 _a in the image clipping device 8, and the quantization processing device 13 is arranged. Each quantization element 10 in
The light receiving element 2 _b in the inside is arranged so as to be directly above each light modulation element 3 in each shape recognition element 5 in the image clipping device 8. Then, a voltage of about 5V is applied between the a terminal and the b terminal in FIG. 1 so that the a terminal side becomes positive, and the + terminal is applied to the c terminal in FIG.
With a voltage of 5 V applied, as shown in FIG. 3, the iron plate, which is the subject 14, was passed under the image processing apparatus A while irradiating with stationary light. At that time, if the surface of the iron plate is smooth, the specular reflection light is not applied to the surface inspection device.

[0009] If a flaw on the surface of the iron plate, the irregular reflection light at the tip portion of the flaw with respect to the moving direction of the steel plate, a portion of the reflected light is incident from the image cutout unit 8 lower the position sensing element 4 _a of the image cutout unit 8 To be done. As a result, the electrical resistance of the light receiving element 2 _a of the incident of the reflected light position detecting element in 4 _a is reduced, the voltage applied to the light receiving element 2 _a and the optical modulation element 3 connected in series is increased, The light modulation element 3 is in a light transmitting state. Therefore, the reflected light is reflected by the light modulator 3
After passing through, the light enters the one position detection element 4 _b in the quantization processing device 13 installed on the upper part of the image clipping device 8 and operates the quantization processing device 13. That is, when the image cropping device 8 operates, the quantization processing device 1
3 also operates almost at the same time. When the reflected light is incident on the light receiving element 2 _a in one position detecting element 4 _a in the image clipping device 8, the voltage applied to the position detecting element 4 _a is decreased, and conversely, it is applied to the shape recognition element 5. The applied voltage increases. Moreover, from the irradiated position sensing element 4 _a of the reflected light, the wiring resistance as shape recognition element 5 is increased in the distant position, as a result, the voltage applied to each of the shape recognition element 5, located far The shape recognition element 5 becomes smaller. That is, from the irradiated position sensing element 4 _a of the reflected light, the shape recognition element light modulation element 3 in 5 located far, not higher than the threshold voltage is applied, the light-absorbing state.

In the case of this embodiment, the unit of distance is as shown in FIG.
If the space between the adjacent shape recognition elements 5 in is adopted,
From the irradiated position sensing element 4 _a of the reflected light, the light modulation device 3 of a distance in a range greater than 2 units shape recognition element 5 were all light-absorbing state. As a result, light reflected by the flaw, by entering into one position detecting element 4 _a of the image clipping device 8, the distance only through the shape recognizing device 5 in the following two units, from all or part of the flaw The reflected light could be transmitted. As a result, it was possible to recognize the location of the scratch image and cut out a part or the whole of the scratch image. Furthermore, the image cropping device 8
The reflected light that has passed through is incident on the quantization processing device 13. That is, the reflected light is incident only on the light receiving element 2 _b in the quantization processing device 13 which is directly above the light modulation element 3 in the light transmitting state in the image clipping device 8. As a result, if the distance between the adjacent position detection elements 4 _b in the quantization processing device 13 in FIG. 2 is adopted as the unit of distance, one position detection element 4 in which the reflected light is incident in the quantization processing device 13 is adopted.
_b (light receiving element 2 _b ) electric resistance and its position detecting element 4
The electric resistance of the light receiving element 2 _b in the quantizing element 10 connected in series with the position detecting element 4 _b within a distance (2 units) from _b is reduced. In the present embodiment, and one in the position detecting elements 4a of the quantization processor 13, the electrical resistance of the total of 21 light receiving elements 2 _b of twenty quantization circuit 11 is reduced. As a result, the voltage applied to the light emitting element 9 connected in series with the light receiving element 2 _b whose electric resistance has decreased increases. Then, only the light emitting element 9 whose applied voltage becomes equal to or higher than the threshold value emits light. That is, the binarization (quantization) process based on the threshold value is performed. In the above embodiments, there is no need to scan the voltage applied to each pixel as is done with CRTs, CCDs, liquid crystals, etc., and since the parallelism of light is used as it is, there is a flaw. The location recognition, segmentation, and quantization can be performed almost simultaneously, and high-speed processing can be performed. A recognition process using a neural network was applied to a part or the whole of the scratch image thus obtained.

According to this embodiment, after the position is detected by the image clipping device 8, a plurality of position detecting elements 4 _{a are formed.}
From any one of the light modulation elements 3, the reflected light caused by the flaw is transmitted. Further, when the distribution of the light modulation elements 3 in the shape recognition element 5 in the light transmission state is viewed from above the image processing apparatus A, the light modulation elements 3 in the position detection element 4 _a in the light transmission state are shown. Left and right are symmetrical with respect to the surface including (the surface parallel to the scanning direction). That is,
In the clipped area, the tip of the scratched image is always located at the upper center of the clipped area, and the position of the scratched image in the clipped area can be specified at this level. Then, with respect to the image by the reflected light cut out by the image cutout device 8, a quantized image by the light emitting element 9 can be obtained almost simultaneously by the quantization processing device 13, and this quantized image also appears at the tip of the scratch image. The corresponding optical signal always emits from the light emitting element 9 in the upper center of the cutout area. This effectively contributes to the neural network in which the recognition rate generally decreases when the position of the target image changes in the clipped image, and the recognition rate can be improved. With the above configuration, it was possible to perform classification by the shape of scratches at high speed and with high recognition rate.

In this embodiment, the case where the voltage applied to the surface scanning device is 5V has been described, but the applied voltage is 1V, 1V.
Even in the case of 0V, 30V, and 100V, it was possible to recognize the flaw by the same method by changing the electric resistance of each element. Moreover, not only scratches but also foreign substances and dirt on the surface of the subject could be recognized.

[0013]

The present invention is constructed as described above. As a result, it is possible to perform the clipping processing and the quantization processing of the image of the surface of the subject almost at the same time, and the parallel processing utilizing the parallelism of light can be performed, and the time division processing can be performed for each pixel of the image. It is not necessary to perform it, and high-speed image cutout processing and image quantization processing can be realized. Then, the quantized image of the surface abnormality is recognized by the neural network, so that the shape of the surface abnormality portion can be classified at high speed and with a high recognition rate.

[0014]

[Brief description of drawings]

FIG. 1 is a wiring block diagram showing an image clipping device 8 which is a component of an image processing device A according to an embodiment of the present invention.

FIG. 2 is a wiring block diagram showing a quantization processing device 13 which is a component of the image processing device A according to an embodiment of the present invention.

FIG. 3 is a conceptual diagram showing a state in which a surface defect image or the like on the surface of a subject is cut out and quantized by using the image processing apparatus.

FIG. 4 is a plan view showing the relationship between a surface defect image and an image processing apparatus.

FIG. 5 is a conceptual diagram of a conventional surface inspection device.

FIG. 6 is a functional block diagram showing a procedure for extracting a characteristic portion from a conventional quantized image.

[Explanation of symbols]

2 _a , 2 _b ... Light receiving element 3 ... Light modulation element 4 _a , 4 _b ... Position detecting element 5 ... Shape recognition element 6 ... Image cutting element 7 ... Resistor 8 ... Image cutting device 9 ... Light emitting element 10 ... Quantization element 11 ... Quantization circuit 12 ... Position detection circuit 13 ... Quantization processing device 14 ... Subject

Claims (2)

[Claims] 1. An image processing apparatus for quantizing an image of a surface of a subject obtained by exposing and scanning the surface of the subject, the shutter element having a small area which is normally closed and is opened by receiving light of a predetermined light amount or more. A plurality of linearly arranged image cut-out means provided in the passage path of the light beam from the subject, and the shutter element of the image cut-out means, which are provided in correspondence with each other and receive the light passing through the shutter element. Quantization provided in the rear of the image cutting-out means as seen in the traveling direction of the light beam from the subject by arranging a large number of quantizing elements having a small area that output a quantized signal according to the light quantity An image processing apparatus comprising a processing means. 2. An exposure scanner that two-dimensionally exposes and scans the surface of the subject to optically detect the surface of the subject based on the amount of reflected light measured from the surface of the subject. In an image processing device that cuts out a predetermined area from an image formed by reflected light from a state and performs quantization processing, a light receiving element whose electric resistance changes by light reception and a light modulation element whose light transmittance changes by applied voltage are connected in series. And a shape recognition element in which a plurality of light modulation elements whose light transmittance changes according to an applied voltage are connected in series, and the position detection element and the shape recognition element are connected in series. A circuit in which a plurality of image cutout elements configured as described above are connected in parallel, and the adjacent connection points of the position detection element and the shape recognition element are connected by wiring having resistance. An image cropping device characterized by
A quantizer circuit composed of a light-receiving element whose electric resistance changes by receiving light and a light-emitting element that emits light when an applied voltage exceeds a certain threshold value are connected in series A quantization processing device comprising a position detection circuit configured by connecting in parallel a position detection element including a light receiving element whose electric resistance changes, and a quantization processing device characterized by a circuit connected in series. The image cut-out device is installed in, and the quantization processing device is installed thereon, and the specular reflection light of the light from the exposure scanner on the object surface is
The image cut-out device and the quantization processing device do not enter, and when an abnormal part exists on the surface of the subject, only the diffused reflected light in the abnormal part enters the image cut-out device and the quantization processing device, An image processing apparatus characterized in that an exposure scanner, the image cutting-out apparatus, the quantization processing apparatus, and a subject are mutually arranged.