JPH05273143A - Image quantization processor - Google Patents

Abstract

PURPOSE:To detect the surface image of a specimen at a high speed by moving a quantization processing means linearly arranged with many quantizing elements relatively to the specimen in the direction perpendicular to the arrangement direction of the quantizing elements. CONSTITUTION:After the position detection by an image extracting device 8, the reflected light caused by a scar is transmitted from either one light modulating element 3 of multiple position detecting elements 4a. The distribution of the elements 3 in shape recognizing elements 5 in the light transmission state is symmetrical on the right and left against the face containing the elements 3 in the elements 4a in the light transmission state, i.e., the face parallel with the scanning direction, when observed from above an image processor. The tip of the scar image is necessarily located at the upper center of an extracting region, and the position of the scar image in the extracting region can be specified at this level. The shape of the scar can be classified at a high speed with a high recognition factor.

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. The present invention relates to an image quantization processing device capable of performing a quantization process on the image optically detected on the surface of the optical specimen based on the above.

[0002]

2. Description of the Related Art Conventionally, as a surface inspection apparatus to which this kind of image quantization processing apparatus is applied, for example, the 34th System Control Information Society Research Presentation Lecture Proceedings (ISCIE, 1st
The apparatus disclosed in pages 03 to 104, '90 -5) can be mentioned. The surface inspection apparatus 1 _a disclosed above is shown in FIG. According to the surface inspection apparatus _1a shown in the figure, the image sensor unit irradiates the surface of the object to be inspected, such as a running steel plate, with laser light or white light from a light source, and performs main scanning with the light reflected from the surface of the object to be inspected. Light is received by a light receiving unit that sequentially scans each pixel in the direction, and the light intensity of the reflected light is converted into an electric signal according to its intensity and output. Then, as shown in FIG. 6, the image processing unit uses 0 (white pixel) or 1 (hatched) for each pixel based on the electric signal from the image sensor unit for each pixel, for example, using a certain threshold value. Pixel) to create a two-dimensional quantized image. 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. 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, it is necessary to improve the image processing function such that the resolution of the image is improved when the size of the entire quantized image is constant, or the entire quantized image is widened when the size of the pixel is constant. When trying to plot,
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,
An object of the present invention is to provide an image quantization processing device capable of speeding up detection of a surface image of a subject.

[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 quantization processing device, the number of linear quantization elements provided in the passage of the light ray from the subject and outputting a quantized signal according to the light quantity of the light ray from the subject is linearly increased. In the image quantization processing apparatus, the arranged quantization processing means is moved relative to the subject in a direction perpendicular to the arrangement direction of the quantization elements. The quantizing element and the quantizing processing means in the present invention are not limited to the structures shown in the embodiments described below, but include any structure that achieves each of the above functions.

[0005]

When the quantizing element is exposed to a predetermined amount of light or more from the subject, 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 as is usually done, and the quantization processing can be performed at the moment when the light from the surface of the subject is incident on the quantization element, A high-speed image processing device 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. 1 is a wiring block diagram showing an image clipping device 8 as a component of a defect inspection apparatus as an application example of the present invention, and FIG. 2 is a wiring block showing a quantization processing device 13 according to an embodiment of the present invention. 3 and 4 are conceptual views 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 is a plane showing a relationship between the surface defect image and the image processing device. It is a figure.

The image cutout device 8 used in the defect detection device together with the image quantization processing device 13 according to the present embodiment is
As shown in FIG. 1, a position detecting element 4 is formed by connecting in series a light receiving element 2 _a whose electric resistance changes by receiving light and a light modulating element 3 whose light transmittance changes by an applied voltage.
_a and a shape recognition element 5 in which a plurality of light modulation elements 3 whose light transmittance changes according to an applied voltage are connected in series, and the position detection element 4 _a and the shape recognition element 5 are connected in series. A plurality of image cutout elements 6 configured in parallel are connected in parallel, and the adjacent connection points of the position detection element 4 _a and the shape recognition element 5 are connected by a wiring having a resistor 7. It is composed of a circuit. Further, a quantization processing device 13 used in combination with the above-described image cutting device
Is a quantum device constructed by connecting in parallel a quantizing device 10 formed by connecting in series a light receiving device 2 _b whose electric resistance changes by receiving light and a light emitting device 9 emitting light by an applied voltage above a certain threshold value. And a position detection circuit 12 formed by connecting in parallel a position detection element 4 _b composed of a light receiving element 2 _b whose electric resistance changes by receiving light. As shown in FIG.
When the image cut-out device 8 is installed directly above, and the quantization processing device 13 is installed on the image cut-out device 8 and is moved at a right angle to the array direction of the quantization elements, the subject 14 of the light from the exposure scanner L is detected. The regular reflection light on the surface is the image cutting device 8 described above.
When the abnormal portion exists on the surface of the subject 14 without entering the quantization processing device 13, only diffused light in the abnormal portion is generated by the image cutting device 8 and the quantization processing device 13.
Incident on. The arrangement position of the image processing device A having the image clipping device 8 and the quantization processing device 13 is determined so that such incident light can be obtained.

[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 position detection circuit 12 corresponds to the quantization element of the present invention, and the quantization processing device 13 corresponds to the quantization processing means. Then, each position detection element 4 in the quantization processing device 13
_b is arranged so as to be directly above the light modulation element 3 in each position detection element 4 _a in the image clipping device 8, and the light receiving element 2 _b in each quantization element 10 in the quantization processing device 13 is , Are arranged so as to be directly above the respective light modulation elements 3 in the respective shape recognition elements 5 in the image clipping device 8. Then, a voltage of about 5V is applied between the a terminal and the b terminal of FIG. 1 so that the a terminal side is positive, and a voltage of + 5V is applied to the c terminal of FIG. 2, as shown in FIG. Subject 1 while irradiating constant light
The iron plate of No. 4 was passed under the image processing apparatus A.
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. In the embodiment described above, in order to cut out a predetermined image and binarize it,
Although the quantizer and the image cutout device are combined, it is not necessary to combine with the image cutout device if the image cutout is not performed separately. It is also possible to combine it with a completely separate image cropping device.

[0013]

The present invention is constructed as described above. As a result, it is possible to perform the quantization process of the image of the surface of the subject by using the parallelism of light, and it is not necessary to perform the time division process for each pixel of the image, and the high-speed image quantization process can be performed. realizable. 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 a surface defect detection device as an application example of the present invention.

FIG. 2 is a wiring block diagram showing an image quantization processing device 13 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 a surface of a subject is cut out and quantized by using the image cutting device.

FIG. 4 is a plan view showing the relationship between a surface defect image and a defect detection device.

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 quantization processing device for performing a quantization process on a subject surface image obtained by exposing and scanning the subject surface,
Quantization processing means which is provided in the passage path of the light beam from the subject and has a large number of linearly arranged quantizing elements having a small area for outputting a quantized signal according to the light quantity of the light beam from the subject. An image quantization processing device, characterized in that is moved relative to the subject in a direction perpendicular to the arrangement direction of the quantization element. 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 for performing a quantization process on an image formed by reflected light from a state, a quantum device formed by connecting in series a light receiving element whose electric resistance changes by light reception and a light emitting element which emits light by an applied voltage above a certain threshold value. And a position detecting device configured by connecting in parallel a position detecting element composed of a light receiving element whose electric resistance changes by light reception, and a quantizing device configured by connecting parallelizing elements in parallel, An image quantization processing device comprising a circuit for applying a voltage from the same power source so that the position detection device side becomes positive and the quantization device side becomes negative.