JPH04171585A - Picture processor - Google Patents

Abstract

PURPOSE:To execute picture processing precisely by finding a precise center point from a temporary center point, picture-processing based on the precise center point and executing the picture processing of a circular body to be image-picked-up. CONSTITUTION:A first picture edge position P2 of a circular body to be image-picked- up is found at the neighborhood of a position separated for the length of the semidiameter of the circular body to be image-picked-up in the first direction from a temporary center point TP, a second picture edge position P3 on a straight line to pass through the first picture edge position P2 and the temporary center point TP is found and a middle point P4 of a line segment to connect the first picture edge position P2 and the second picture edge position P3 is found. Then, a third picture edge position P6 is found at the neighborhood of the position separated for the length of the semidiameter in the second direction except the first direction from the middle point P4, a position CP separated for the length of the semidiameter in the opposite direction of the second direction from the third picture edge position P6 is found and the processing of a picture is executed with the position as the center point CP of the circular body to be image-picked-up. Thus, the precise center of an object to be checked 100 can be found.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an image processing device.

(Conventional technology) When steel materials such as special steel used for parts of automobiles and industrial machinery come into contact with oxygen in the atmosphere during manufacturing processes such as rolling and heat treatment, carbon in the steel reacts with oxygen in the atmosphere. However, it dissipates from the steel material as Co and co2. Therefore, the carbon content on the surface and near the surface of the steel material is
lk). (Usually called decarburization.)
For example, when forming a bolt from a steel wire, the bolt is formed using a bolt forming machine without cutting the surface of the steel material, leaving the rolled or heat-treated surface intact. Therefore, if a decarburized layer occurs in the steel material, the decarburized layer also remains in the bolt. 20 Since the strength of the decarburized layer is low, the bolt may break during use.

Although it is important for steel manufacturers to improve the manufacturing method of steel products that are virtually free from decarburization, it is also important to have inspection techniques to ensure that the steel products are free from decarburization to users.

Therefore, it is necessary to periodically inspect the quality of steel materials. This inspection is performed by cutting out a portion of the steel material, making a sample with the surrounding area hardened with resin, and then performing image processing on the cut surface of this sample to measure the state of decarburization from the density information.

By the way, the state of decarburization is determined by examining the depth to which decarburization has progressed from the surface layer of the steel material toward the center.

For this reason, it is necessary to find the exact center of the steel sample.

However, with conventional inspection equipment, it is difficult to find a sufficiently accurate center of the steel sample because the alignment is performed using a positioning device, etc. This inspection requires skill and requires a large amount of man-hours. Therefore, an image processing device that can accurately determine the center has been desired.

(Problems to be Solved by the Invention) As mentioned above, it is difficult to find a sufficiently accurate center of a steel sample using conventional steel decarburization inspection equipment. It was desired.

The present invention was devised to solve the above problems, and an object of the present invention is to provide an image processing device that can accurately determine the center of an object to be inspected.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the inspection apparatus of the present invention includes an image input means for inputting an image of a circular object to be imaged, and an image input means for inputting an image from the image input means. provisional center point determining means for determining a provisional center point of an image of the circular imaged object; A first image edge position of the circular imaged object is determined, a second image edge position on a straight line passing through the first image edge position and the temporary center point is determined, and the first image edge position and the second image edge position are determined. Find the midpoint of the line segment that connects the second image edge position, and move the third image edge near a position away from the midpoint by the length of the radius in a second direction different from the first direction. determining a position, determining a position separated by the length of the radius in a direction opposite to the second direction from the third image edge position, and determining a center point by setting this position as the center point of the circular object to be inspected; and an image processing means for performing predetermined image processing on the image of the circular object based on the center point calculated by the center point calculation means.

(Function) In the image processing device of the present invention, the first image edge position of the circular imaged object is determined in the vicinity of a position that is a radius of the circular imaged object in the first direction from the temporary center point. Find the second image edge position on the straight line passing through the first image edge position and the temporary center point, and find the midpoint of the line segment connecting the first image edge position and the second image edge position. A third image edge position is found near a position a radius away from this midpoint in a second direction other than the first direction, and a third image edge position is found in the opposite direction from the third image edge position. Find a position that is the length of the radius in the direction, and use this position as the center point of the circular object to be imaged.
Image processing is performed using this center point as a reference.

Therefore, image processing is performed using a more accurate center point as a reference, resulting in higher accuracy.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of a decarburization inspection apparatus which is an embodiment in which the image processing apparatus of the present invention is applied to decarburization inspection of steel materials.

As shown in the figure, this decarburization inspection device is used for steel sample 1.
The main parts are composed of an optical system 200 for obtaining an enlarged video signal of 00, and a processing system 3OO for performing image processing on the video signal obtained by the optical system 200 and inspecting decarburization.

The optical system 200 includes a holder 2 that stores the steel sample 100.
10, an optical microscope 220 that optically magnifies the cut surface of the steel sample 100, and an ITV (INDUSTRIAL EVIS) that photographs the cut surface of the steel sample 100 magnified by the optical microscope 220 and converts it into a video signal.
ON) A camera 230, an illumination device 240 that illuminates the cut surface of the steel sample 100, an autofocus controller 250 that controls the autofocus mechanism provided in the microscope 220, and a holder 210 that is held and moved on a plane. X-Y stage 260 and image processing system 300
and an X-Y stage controller 270 that controls the movement of the X-Y stage 260 based on instructions from the X-Y stage controller 270.

A processing system 300 includes an information processing device 310 that controls the entire decarburization inspection device and processes measurement data, and a processing system 300 that inputs video signals from an ITV camera 230 based on instructions from the information processing device 310 to perform decarburization inspection. an image processing device 320 that performs image processing necessary for image processing, an image monitor 330 that displays raw images taken by the ITV camera 230, and an image monitor 3 that displays images processed by the image processing device 320.
40, a video printer 350 that outputs a hard copy of an image processed by the image processing device 320, and a printer 360 that prints measurement data processed by the information processing device 310.

FIG. 2 is a block diagram showing the configuration of the image processing device 320.

As shown in the figure, the image processing device 320 includes a CPU 321 that controls the entire image processing device 320, and an A/D converter 322 that converts the density data of the video signal input from the ITV camera 230 into digital values. A frame memory 323 that stores image data converted by the A/D converter 322, an image processing processor 324 that performs image processing of the image data stored in the frame memory 323, and an image processing processor that performs image processing. This is the work RAM to be used.

FIG. 3 is a perspective view showing the steel sample 100.

As shown in the figure, a steel sample 100 has a piece of steel 101 cut out from a steel material, and its surroundings are hardened with black resin 102.
It is cylindrical.

Next, the operation of the decarburization inspection apparatus configured as described above will be explained.

First, an image of the entire steel sample 100 is captured by the ITV camera 230. A tentative center point TP of the steel piece 101 of the steel sample 100 is determined by an alignment device (not shown) or by taking projections of the entire image of the steel sample 100 in the X and Y directions. Further, the length of the radius of the steel material registered in advance in the information processing device 310 is assumed to be R.

Next, the operation of determining a more accurate center point CP from this temporary center point TP will be explained.

FIG. 4 is a diagram for explaining the operation of determining the center point CP.

First, a position P located R away from the temporary center point TP in the positive direction of the X-axis.
When the density of one pixel is detected and it is determined that the surface is a steel material surface, the density of pixels in the positive direction of the X axis is further sequentially measured, and the boundary point P2 between the steel piece 101 and the resin 102 is determined.

(Figure (a)) As a result of detecting the density of the pixel at position P1,
If it is determined that the surface is a resin surface, pixels in the negative direction of the X-axis are sequentially measured to find a boundary point P2 between the steel piece 101 and the resin 102. ((b) in the figure) Once the boundary point P2 is determined, the density of pixels in the negative direction of the X axis is sequentially measured to determine the boundary point P3 between the steel piece 101 and the resin 102.

(Figure (c)) Furthermore, find the midpoint P4 of the line segment connecting boundary point P2 and boundary point P3. (Figure (d)) Next, find the position RM from the midpoint P4 in the positive direction of the Y axis. P5
If the density of the pixels is detected and it is determined that the surface is a steel surface,
Furthermore, the density of pixels in the positive direction of the Y axis is sequentially measured, and a boundary point P6 between the steel piece 101 and the resin 102 is determined. (
(e) of the same figure) Next, as a result of detecting the density of the pixel at position P5, which is R away from the midpoint P4 in the positive direction of the Y-axis, if it is determined that it is a resin surface, the density of the pixel is detected in the negative direction of the Y-axis. The boundary point P6 between the steel piece 101 and the resin 102 is determined by sequentially measuring the pixels. ((f) in the same figure) Then, a point separated by R in the negative direction of the Y-axis from the boundary point P6 becomes the center point CP.

After the center of the steel piece 101 is determined in this way, image processing is performed.

First, as shown in FIG. 5, an image of the peripheral portion of the steel piece 101 is captured for a screen F1. 1 on frame memory 323
The image data for the screen is divided into 255 sectors as shown in FIG. 6, and density data is added for each sector and stored in the work RAM 325.

Next, the X-Y stage controller 270 performs
The movement of the Y stage 260 is controlled to capture an image for screen F2 adjacent to screen Fl. Similarly, the image for screen F2 is divided into 255 sectors on the frame memory 323, and density data is stored for each sector. is added and the working RAM3
25.

Similarly, the density data for each sector of the images corresponding to screens F3 and F4 is added and stored in the work RAM 325.

FIG. 7 is a graph showing the relationship between the integrated value of density data for each sector and the sector. Work RA shown in this graph
The integrated density data for each sector stored in the RAM 325 is smoothed, converted into data shown in FIG. 8, and stored in the working RAM 325 again.

The decarburization depth D is the distance from the edge A of the steel piece 101 to the position B where the surface concentration of the steel piece 101 is not decarburized.
T is measured. 20 If the decarburization depth DT is greater than a predetermined value, it is determined that the product is defective. Further, a graph of the distance from the edge toward the center of the steel piece and the image density data shown in FIG. 8 is displayed on the image monitor 340.

In the decarburization inspection device of this embodiment, a more accurate center point is determined from the temporary center point, and the decarburization inspection is performed using this accurate center point as a reference, so the depth of decarburization of the steel material can be accurately measured. Ru.

[Effects of the Invention As explained above, according to the image processing device of the present invention,
An accurate center point is determined from the temporary center point, and image processing of the circular imaged object is performed based on this accurate center point. Therefore, image processing is performed accurately.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of an embodiment of the decarburization inspection device of the present invention, Fig. 2 is a block diagram showing the configuration of the image processing device, Fig. 3 is a perspective view showing a steel sample, and Fig. 4 is Figure 5 is a diagram for explaining the operation of determining the center point of a steel piece. Figure 5 is a diagram showing a screen for capturing an image of a steel sample. Figure 6 is a diagram showing how one screen image is divided into sectors. FIG. 7 is a graph showing the relationship between the integrated value of the density data for each sector and the sector, and FIG. 8 is a diagram showing the state after the density data shown in FIG. 7 has been smoothed. 100... Steel material sample, 101... Steel material piece, 10
2... Resin, 200... Optical system, 210... Holder, 220... Optical microscope, 230... ITV camera, 24O... Illumination device f, 250... Auto focus controller, 260 ...x-y stage 27
0... x-y stage controller, 300... processing system, 310... information processing device, 320... image processing device, 330.340... image monitor, 350...
・Video printer, 360... printer. Applicant: Toshiba Engineering Co., Ltd. Daido Steel Co., Ltd. Agent Patent attorney: Sa Suyama - (1 other person) Nao L - - 1 - ■ - - - Sea axis - Tatami, -11 Seiichi --" Figure 2 31 yen) Figure 4 F4 Haru 51 tqri 253 61 yen:l

Claims (1)

[Claims] (1) an image input means for inputting an image of a circular object to be imaged; a temporary center point calculating means for calculating a temporary center point of the image of the circular object to be imaged inputted from the image input means; A first image edge position of the circular imaged object is determined in the vicinity of a position separated by the length of the radius of the circular imaged object in a first direction from the point, and this first image edge position and the temporary center are determined. Find the second image edge position on the straight line passing through the first point.
Find the midpoint of the line segment connecting the image edge position and the second image edge position, and calculate the distance from the midpoint by the length of the radius in a second direction different from the first direction. Third
Find the image edge position of the third image edge position, find a position away from the third image edge position by the length of the radius in the opposite direction to the second direction, and set this position as the center point of the circular object to be inspected. Image processing characterized by comprising a point finding means and an image processing means for performing predetermined image processing on the image of the circular imaged object based on the center point found by the center point calculating means. Device.