JPH07286822A - Method for measuring dimension from picture - Google Patents

Abstract

PURPOSE:To measure the inclination of a rectangle with accuracy by means of a picture processor and, at the same time, to measure the width of the rectangle to the same accuracy as that obtained when the width is visually measured. CONSTITUTION:The center of gravity of a nearly rectangular picture is found and a vertical line which passes through the center of gravity and is perpendicular to scanning lines is set. Then first and second lines perpendicular to the vertical line are drawn at an interval (h) and the area A1 of the quadrangle ABCD specified by the points A and B where the first line intersects the near rectangle and points C and D at which the second line intersects the near rectangle, is found. The area surrounded by the outermost ones on both sides of the perpendiculars drawn from the intersections A, B, C, and D to the first and second lines and the first and second lines is made to be A0 and the angle thetaexpressed by theta=tan<-1>(A0-A1)/h<2> is made to be the angle between the center line which passes through the center of gravity of the near rectangle and indicates the direction of the longer sides of the rectangle, and the vertical line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of measuring an inclination angle and a width of an image having a shape close to a rectangle (hereinafter simply referred to as a rectangle) having a wavy shape on each side. The present invention relates to a method of measuring by image processing so as not to make a big difference with the visual measurement.

[0002]

2. Description of the Related Art Television shadow masks and ICs
In the case of making a hole in a (integrated circuit) substrate, exposure etching is performed. This is a processing method in which the pattern to be processed is enlarged and drawn on a transparent film, and a reduced image is obtained by projecting an image onto a target surface coated with a photosensitive agent to form an image, and then etching this to obtain the target pattern. Is.
When a rectangular small hole is formed by such exposure etching, the smaller the hole is, the more the laser light used for exposure is extruded due to refraction by diffraction, and when the rectangle on the film is projected, the center tends to be dented in a cocoon shape. On the other hand, the shadow mask is a CRT
A barrel-shaped rectangle is used because a barrel-shaped shape having a bulge in the center is preferable for converting the scanning image formation of the (cathode ray tube) into an electric signal. Since each side of the rectangle is particles of the photosensitizer itself and etching progresses like rust, it is not a straight line but an uneven curve. In addition, in many cases, the unevenness has a small width but a large peak randomly mixed.

FIG. 8 shows the shape of a rectangular small hole obtained by exposure etching. (A) shows a barrel-shaped rectangle,
(B) shows a cocoon-shaped rectangle. Each side is composed of a curve of unevenness, and the unevenness has a narrow width but a large peak. As an example of the size of a rectangle, the quadrangle (width) is 8
The peak-to-peak wave height is 0 to 200 μm, the peak to peak is 4 to 10 μm, and the large wave height that occurs suddenly is about 2 to 3 times that of most other waves. Further, when this rectangle is imaged by a television camera connected to a microscope and displayed on a CRT, the size of one pixel is about 2 μm, so the width of the rectangle is 40 to 100 pixels, and the normal peak to peak of unevenness is measured. Is represented by 2 to 5 pixels. Moreover, the period of the unevenness is 3 to 8 pixels.

With respect to a rectangle having such a shape and size, the inclination θ and width of the rectangle are measured. At the same time, the relative position and spacing of the rectangles in the vicinity are also measured. Conventionally, the measurement was performed by visually moving the crosshair and the image relatively in the visual field of the microscope.
When this is automatically measured by image analysis, the inclination θ is the inclination of the center line S passing through the center of gravity G of the rectangle and indicating the direction of the long side with the line Q perpendicular to the scanning line P of the CRT screen, as shown in FIG. It is represented by the angle θ. For the measurement of the angle θ, a center of gravity G of a rectangle is obtained, and a line segment that passes through the center of gravity G and intersects with the rectangle is obtained. Using the bisector of L1 and L2 as the center line S, θ was obtained as the angle with the vertical line Q perpendicular to the scanning line P.

When a person measures the width of a rectangle by using a crosshair of a microscope, an average line can be drawn as shown in FIG. 8 to obtain a measurement with good resolution and reproducibility. On the other hand, FIG.
0 indicates an automatic measurement method by image analysis of the width of a rectangle.
(A) is a dimension obtained from a line segment parallel to the width, and the angle θ of the center line S with respect to the vertical line Q perpendicular to the scanning line P is obtained by the above-described method, passing through the center of gravity G, and the line segment of the angle θ to the scanning line P. Draw a line segment before and after this line segment in parallel, find the intersections of each line segment and the rectangle, find the length between the intersections for each line segment, and calculate the average value of this length as the width of the rectangle. To do. The distance between the parallel lines was set to be several pixels apart. (B) is a method of obtaining from the area, and it is drawn with two parallel lines H1 and H2 spacing h orthogonal to the center line S with the center of gravity G sandwiched between them and surrounded by these two line segments H1 and H2 and the long side of the rectangle. This is a method in which the area indicated by the hatched line is obtained and the value obtained by dividing this area by h is used as the width.

[0006]

However, in order for a person to visually measure with a crosshair, human power is required, which causes fatigue and takes a long time. When the angle θ is measured by the method based on the image analysis shown in FIG. 9, the line segments L1 and L2 are determined by the shapes of the four corners of the rectangle, but the shapes of these four corners are often collapsed and are greatly affected by the deformation due to unevenness. As a result, a large error occurs in the determination of the line segments L1 and L2, and the error of the angle θ of the center line obtained by the bisector is large.

In the method shown in FIG. 10 (A), the pitch of the parallel lines matches the pitch of the concavities and convexities on the long sides of the rectangle, and the parallel lines only come to the positions of the concave portions on both sides, or only the positions of the convex portions. In many cases, such measurement data is different from the case where the rectangular shape is linearized by visual observation and the distance between the long sides is measured. In the case of visually lining up uneven sides, the maximum and minimum data are often unconsciously removed and straightened.
Another reason is that such processing is not performed.

Further, in the method shown in FIG. 10 (B), when h is set large, when the rectangle has a barrel shape, it includes a portion having a small distance between opposite sides which is deviated from the bulge at the center, which is smaller than a visually measured value. It will be a small value. Further, when h is made small, the area shown by diagonal lines changes depending on how the pixels representing the parallel lines H1 and H2 are taken. Fig. 11 shows parallel lines H1 and H2 when calculating the area.
In a diagram for explaining how to take a pixel represented by, the area size is different between when the pixel represented by the solid line is taken and when the pixel represented by the broken line is taken. Note that, in FIG. 11, straight lines L1 and L2 drawn along the long side represent average lines drawn by a person when visually observed.

The present invention has been made in view of the above problems, and a method of accurately calculating the inclination of a substantially rectangular shape by an image processing apparatus and a method of measuring the width of a substantially rectangular shape with the same accuracy as the visual measurement. The purpose is to provide.

[0010]

In order to achieve the above object, the center of gravity of a substantially rectangular image is obtained, a vertical line passing through the center of gravity and orthogonal to the scanning line is set, and at a distance h orthogonal to the vertical line. The first line and the second line are drawn, the intersection of the first line and the substantially rectangular shape is A, B, the intersection of the second line and the substantially rectangular shape is C, D, and the quadrangle A
Obtain the area A1 of the BCD, draw a perpendicular line from the intersection points A, B, C, D to the first line and the second line of the opponent, and set the area enclosed by the perpendicular line at both ends and the first line and the second line as A0, θ = tan ⁻¹ (A0−A1) / h ² (1) θ expressed by the equation (1) is an angle between the center line indicating the direction of the long side and the vertical line passing through the center of gravity of the substantially rectangular shape. To do.

Further, the center of gravity of a substantially rectangular image is obtained, and an angle θ between a vertical line passing through this center of gravity and orthogonal to the scanning line and a center line passing through the center of gravity of the substantially rectangle and indicating the direction of the long side is determined by a predetermined method. Find, draw each line that makes an angle θ ± mΔθ (m is an integer) with the scanning line through the center of gravity, find the intersection of each line and the rectangle, find the length of the line segment between the intersections of each line, and find the maximum and minimum values Is a method of calculating the average value M of the remaining lengths except that the estimated value of the average value M is Δθ, and Δθ · M ′ / 2 is defined in the vicinity of the intersection of the substantially rectangular shape and the line segment. The size is set to be about one pixel, and the m is defined so as to include one or more sets of concavo-convex representing the wave of the side of the substantially rectangular shape within the crossing range of the 2m + 1 lines.

Further, the center of gravity of a substantially rectangular image is obtained, and an angle θ between a vertical line passing through this center of gravity and orthogonal to the scanning line and a center line passing through the substantially center of gravity and indicating the direction of the long side is determined by a predetermined method. Obtain a reference line that passes through the center of gravity and forms an angle θ with the scanning line, draw a total of n lines in parallel with this reference line at a pitch δ, including this reference line, and between the intersections of these lines and the sides of the substantially rectangular shape. Of the line segment and the remaining average value N excluding the maximum value and the minimum value is obtained, wherein the pitch δ is about one pixel size, and n is a substantially rectangular side. It is determined that at least one set of unevenness representing the corrugation is included within the intersection range of the n lines.

Further, the coordinate points of the line segment that intersects the substantially rectangular shape use the center points of the pixels or the center points of the four pixels arranged in the squares. If there is no intersection at this coordinate point position, The length of the line segment is calculated with the line that passes through the center of gravity and forms an angle θ with the scanning line as the inner side and the center of the closest pixel or the center point of the four pixels on the outer side of the corresponding line segment as the intersection.

[0014]

FIG. 2 is a diagram for explaining a method of calculating the inclination θ of a substantially rectangular shape. The image captured by the television camera attached to the microscope is displayed in pixels. When displaying an image on a display device, a line perpendicular to the scanning line P is defined as a vertical line Q, and a center of gravity G of a rectangle is set.
The centerline S is a line that passes through and extends along the long side.
The angle θ between the vertical line Q and the vertical line Q is a substantially rectangular inclination. The value obtained by subtracting the substantially rectangular area A1 represented by the diagonal lines from the area A0 of the quadrilaterals A, E, D, and F is the triangle AEC and the triangle BD.
The area of F is shown, and the area is divided by h (A0-A
1) / h represents the average value of the straight line CE and the straight line BF. Angle C
If AE is θa, angle BDF is θb, and the average angle of θa and θb is θ, then h · tan θ = (A0−A1) / h holds, and equation (1) is derived from this equation. The inclination of the rectangle.

FIG. 4 is a diagram showing a method of calculating the width M near the center of gravity of a substantially rectangular shape in which the angle between the center line S and the vertical line Q is θ. A reference line T which is an inclined straight line is drawn. The reference line T is orthogonal to the center line S. Radially straight lines are drawn from the reference line T at an angle of Δθ at right and left sides to obtain intersections with a substantially rectangular shape, and the length of the line segment between these intersections is obtained. The average value M is calculated. Let this average value M be the width of a substantially rectangular shape. By excluding the maximum and minimum values, sudden peak values can be eliminated and an appropriate average value can be obtained. Let Δθ · M '/ 2, which represents the pitch of the radial straight line near the intersection, be approximately the size of one pixel, and the radial straight lines allow each radial straight line to be located only at the positions of the concave portions on both sides of the rectangle. It reduces the probability of passing through and only the position of the convex portion. Also, 1
By providing a radial line in a range including more than one set of irregularities, it is possible to represent the average position of the sides of a substantially rectangular shape. When the above is put together, the result close to the visual measurement is obtained. By averaging the lengths between the intersections of a plurality of straight lines, a resolution exceeding the resolution of the size of each pixel (for example, 2 μm) can be obtained. In the actual example, 1μ by averaging
Measurement results with a reproducibility of about m can be obtained.

FIG. 6 is a diagram showing another method for calculating the width N near the center of gravity of a substantially rectangular shape in which the angle between the center line S and the vertical line Q is θ, and unlike FIG. 4, parallel to the reference line T, N lines including the reference line T are drawn at intervals of about 1 pixel to obtain intersection points with the substantially rectangular shape. Next, the length of the line segment between the intersections is calculated, and the average value N is calculated except for the maximum value and the minimum value. Compared with the conventional method of measuring the width using parallel lines, the pitch is as small as about 1 pixel,
By setting the range of the parallel lines to a range including one set of concaves and convexes, it is less likely that each parallel line will pass only the positions of the concave portions and the positions of the convex portions on both sides of the substantially rectangular shape. Similar to the method shown in FIG. 4, a result close to the visual measurement is obtained.

The length between the intersections of line segments that intersect the substantially rectangular shape is calculated as the length between coordinate points representing pixels, and the coordinates representing pixels are pixels arranged in squares as shown in FIG. The center point (A) or the pixel center (B) is used, and one of the images is used so as not to be mixed. Both sides of the substantially rectangular shape and the radial lines shown in FIG. 4,
When the parallel lines shown in FIG. 6 intersect and the position of the intersection does not coincide with the center of the pixel or the center of the four pixels, that is, the coordinates representing the pixel on the intersection with the corresponding radial line or parallel line. If there is not, the coordinates representing the closest pixel on the outside of the radial line or parallel line are used with the reference line T shown in FIGS. 4 and 6 as the inside. By doing so, the positions of radial lines and parallel lines can be displayed by pixels at a pitch of 1 pixel or less.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the arrangement of an apparatus for realizing this embodiment. An image pickup lens 16 is attached to the eyepiece portion of the microscope 1 and an image pickup device 16 for picking up an image through the image pickup lens is attached. The stage 17 on which the measurement sample is placed is subjected to plane position adjustment by a plane moving mechanism 18 for moving the stage 17 back and forth and left and right by a pulse motor provided on the stand in response to a signal from the auto stage driver 10.
Vertical movement mechanism 19 by autofocus driver 11
Is operated to move the stage 17 in the vertical direction to focus. When inspecting the shadow mask of a TV, the shadow mask is rotated on the auto stage by a certain angle to bring the inspection point into view, and the hole is tilted with respect to the scanning line to increase the measurement accuracy. There is a mechanism.

The A / D converter 2 converts the input data from the image pickup device 16 from analog to digital, and the input buffer 3 temporarily stores the digital data. The bus 4 transmits signals, the program memory 5 stores a program that defines the operation of the apparatus, and the CPU 6 controls the entire apparatus according to this program.

The image processor 7 performs grayscale processing, binarization processing, image analysis, etc. of the input image data, the grayscale image memory 8 stores the grayscale image data, and the binarization memory 9
Stores the binarized image data. The auto-stage driver 10 controls the plane moving mechanism 18 to move the stage 17 on which the measurement sample is placed in the X and Y directions according to an instruction from the CPU, and sets the measurement position and area of the measurement sample. The autofocus driver 11 receives a control command from the CPU 6 to the vertical movement mechanism 19, controls the vertical movement mechanism 19,
Focus automatically. The output buffer 12 temporarily stores the data to be output, the D / A converter 13 converts the output data from digital to analog, and the CRT 14 displays the output data on the screen. The operator inputs instructions and data from the keyboard 15.

Next, as a first embodiment, a method for calculating the inclination θ of the rectangle will be described with reference to the flow charts shown in FIGS. First, a rectangular image is captured to obtain image data (ST1). Next, the center of gravity G of the rectangle is obtained from this image data (ST2). A vertical line Q orthogonal to the scanning line P for displaying an image through the center of gravity G is set (ST3), and a first line L1 and a second line L2 orthogonal to the vertical line Q are separated by an interval h.
And then the intersections A and B of the first line L1 and the rectangle, the second line L2
And intersections C and D of the rectangle are set (ST4). Next, a perpendicular is drawn from the intersection to the line on the other side, and the area A0 of the quadrangle AFDE surrounded by the outermost perpendicular and the first line L1 and the second line L2 is obtained (ST5). The area A1 of the quadrangle A, B, C, D is calculated, and h, A0, A1 are substituted into the equation (1), and θ
(ST6). A line that passes through the center of gravity G and is inclined by θ with respect to the vertical line Q is a rectangular center line S.

Next, a method for measuring the width of a rectangle will be described as a second embodiment. FIG. 4 is a diagram showing a method for measuring the shape and the width M of the barrel rectangle in the vicinity of the center of gravity, and FIG. 5 is a flowchart of the second embodiment. In FIG. 4, a vertical line Q is a line perpendicular to the scanning line P, and a center line S is a vertical line Q passing through the center of gravity G and a straight line inclined by θ obtained in the first embodiment. It should be noted that θ may be a value obtained by a method other than the first embodiment, for example, an angle obtained by the conventional example shown in FIG. The reference line T is a straight line that passes through the center of gravity G, is inclined by θ with respect to the scanning line P, and is orthogonal to the center line S. The shape of the long side near the center of gravity G of the rectangle is shown by the left and right stepwise solid lines, and the pixels indicated by the diagonal lines are squares to show the outline of the pixels, as shown in some detail.
The straight lines L3 and L4 are imaginary lines drawn in parallel to the center line S after the width M of the rectangle is obtained, in order to show M easily.

According to this method, m lines are drawn radially through the center of gravity G around the reference line T at every angle Δθ, the intersections with the left and right long sides are obtained, and the length between the intersections of the line segments is calculated. The average value M is calculated and used as the width near the center of gravity G of the rectangle. In calculating the average value, the maximum and minimum values are excluded as abnormal values, and the remaining values are averaged. Further, Δθ is set so that the value of Δθ · M ′ / 2 is about one pixel size (about 0.3 to 1.5 times the size of one pixel), where M ′ is the expected width. Set. The value of Δθ · M ′ / 2 corresponds to the pitch of the intersections of the lines drawn for each angle Δθ with the straight lines L3 and L4. Assuming straight lines L3 and L4 for the value of m, one set of concave and convex waveforms with L3 and L4 as the center is 1
More than one set (preferably about two sets) is defined so that it can be covered by 2m + 1 radial lines. FIG. 4 shows the case of one set.

Radial lines drawn on the left and right sides of the reference line T at intervals of Δθ are m = 1, 2,
3, ..., clockwise m = -1, -2, -3, ...
Is displayed. The intersection of the reference line T, each radial line m, and the long side of the rectangle does not often coincide with the center point of the four pixels representing the coordinates of the pixel shown in FIG. 7 or the center of the pixel. In this case, The reference line T is the coordinate point of the pixel closest to this intersection, and the intersection with each radial line m is the coordinate point of the pixel closest to the outside of each radial line m with the reference line T inside. The distance between the intersections of the line segments is calculated from the distance between the coordinate points. A method of moving the intersection of the radial line m = -5 and the long side to the coordinate point -5p as shown by an arrow will be described in detail in part of FIG. In this case, the center point of the four pixels shown in FIG. 7A is used as the coordinate point, but it may be the center of the pixel shown in FIG. 7B. However, unify to either one. The coordinates of the pixel at each intersection are indicated by mp and mq, where mp indicates the coordinates of the intersection with the right long side, and mq indicates the coordinates of the intersection with the left long side.
Find the distance between the intersections mp and mq. When the average value M obtained as described above and the estimated value M ′ are significantly different, M is used as M ′ and the average value M may be obtained again.

Next, a method for measuring the width of a rectangle will be described with reference to the flow chart of the second embodiment shown in FIG. In this embodiment, the operation shown in the flow chart of the first embodiment is performed subsequently,
It is assumed that the rectangular image data, the center of gravity G, the center line S, and the inclination θ of the center line S are already stored in the image processing apparatus shown in FIG. First, Δθ, m is input from the keyboard 15 (ST11). As for the value of Δθ, the estimated value M ′ of the width is obtained, and Δ
Although θ · M ′ / 2 is set to be about one pixel, the value of Δθ is also constant when the size of the rectangle is almost fixed. In this embodiment, the size of one pixel is 2
It is about μm. M to determine the number of radial lines 2m + 1
The value of is determined so as to cover one to two sets of irregularities on the long side of the rectangle, but since one concave or convex is often composed of 3 to 5 pixels, in the case of one set, m = 5. In case of 2 sets, m =
It can be predetermined as 10.

Next, a reference line T passing through the center of gravity G and orthogonal to the center line S is obtained (ST12). The reference line T is passed through the center of gravity G, the angle Δθ is pitched to the left and right, and 2m + 1 radial line segments including the reference line T are drawn to obtain intersections with the left and right long sides of the rectangle (ST13). ). When the intersection is not at the coordinate point of the pixel of the image, the reference line T is set to the inside, and the coordinate point of the pixel closest to the outside of the corresponding radial line m is set to the intersection (ST14). With respect to the reference line T and each radial line m, the distance between the intersections is calculated, the maximum value and the minimum value are excluded, and the remaining average value M is calculated (ST15).

Next, another method for measuring the width of a rectangle will be described as a third embodiment. In the second embodiment, the width is calculated from the intersection of the radial line segment passing through the center of gravity G and the long side of the rectangle, whereas in the present embodiment, the width is calculated in parallel with the reference line T at a pitch of about one pixel. A parallel line is drawn, and the width is obtained from the intersections of n parallel lines including the reference line T and the rectangle. Figure 10
By making the pitch smaller than in the conventional example shown in (A) and excluding the maximum value and the minimum value when obtaining the average value, a value close to the visually measured value can be obtained.

FIG. 6 is a diagram showing a method of measuring the shape and the width N of the barrel-shaped rectangle in the vicinity of the center of gravity as in FIG. 6, the scanning line P, the vertical line Q, the center line S, the angle θ between the vertical line Q and the center line S, the reference line T, and the straight lines L3 and L4 are the same as those in FIG. This method draws n parallel lines including the reference line T at a constant pitch δ in parallel with the reference line T, obtains the intersections with the long sides of the left and right rectangles, and calculates the length between the intersections of the line segments. The average value N is obtained and used as the width near the center of gravity G of the rectangle. When calculating the average value, average the remaining values excluding the maximum and minimum values. The pitch δ is about the size of one pixel (1
The value of n is about 0.3 to 1.5 times the number of pixels), and the value of n is one or more waveforms for one set of concave and convex centering on L3 and L4, preferably about two sets, assuming straight lines L3 and L4. To be covered with n parallel lines. When the intersection of the parallel line and the long sides of the left and right rectangles is not on the coordinate point of the pixel described in FIG. 7, the reference line T is the coordinate point of the closest pixel, and the other parallel lines are the reference points. The line T is defined as the inner side and is the coordinate point of the pixel closest to the outer side of the corresponding parallel line. In the present embodiment, the n parallel lines have the same number in the vertical direction with respect to the reference line T, but they do not necessarily have to have the same number in the vertical direction. In FIG. 6, the number attached to the parallel line indicates the number of each parallel line, and n
p indicates the coordinate point of the pixel at the intersection on the right side of the parallel line n, and nq
Indicates the coordinate point of the pixel at the intersection on the left side.

The flow chart of this embodiment is almost the same as the flow chart of the second embodiment of FIG. 5, and the pitch δ is set to about the size of one pixel, and the value of n is 10 (in the case of one set of concave and convex). It is set to a value of 20 (in the case of about two sets of unevenness).

The rectangular shape has been described as a barrel shape, but since it is not the measurement unique to the barrel shape, the cocoon shape also has
Moreover, the method of each embodiment can be applied to the measurement of the inclination θ of the center line and the width M (or N) of an ordinary rectangle whose opposite sides are parallel. Also, the distance between rectangles can be measured.

[0031]

As is apparent from the above description, according to the present invention, the inclination angle θ of the rectangular center line is calculated by measuring the area, so that the change in shape can be absorbed and the measurement can be performed accurately. In addition, the width near the center of gravity of the rectangle is drawn through the center of gravity through the center of gravity, and radial lines are drawn to the left and right at a pitch of Δθ centering on the reference line T, and the distance between the intersections with the long sides of the rectangle is calculated for each line And the average value of the values excluding the minimum value is the width,
The pitch of Δθ is set to about 1 pixel near the intersection, and the value of m is set to be 2m + 1 radial lines so as to cover at least one set of irregularities on the sides of the rectangle, and the width measured visually. You can get the same accuracy range as. In addition, n parallel lines including the reference line T are drawn in parallel with the reference line T at a pitch of about 1 pixel through the center of gravity of the rectangle, the intersections with the rectangle are obtained, and the distances between the intersections of the parallel lines are obtained. The average value of the values excluding the maximum value and the minimum value is taken as the width, and the value of n is the width measured visually by defining the n parallel lines so as to cover at least one set of irregularities on the sides of the rectangle. A range of almost the same accuracy can be obtained. By obtaining the average value, a resolution exceeding the resolution due to the pixel size can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of an image processing apparatus that implements an exemplary embodiment.

FIG. 2 is a diagram illustrating a method of calculating a tilt θ of a rectangle according to the first embodiment.

FIG. 3 is an operation flowchart of the first embodiment.

FIG. 4 is a diagram illustrating a method of measuring a width of a rectangle according to a second embodiment.

FIG. 5 is an operation flow chart of the second embodiment.

FIG. 6 is a diagram illustrating a method of measuring the width of a rectangle according to a third embodiment.

FIG. 7 is a diagram showing coordinate points representing pixels.

FIG. 8 is a diagram showing a rectangular shape processed by exposure etching and a width measurement by visual observation.

FIG. 9 is a diagram illustrating a conventional method for measuring the inclination θ of a rectangle.

FIG. 10 is a diagram illustrating a conventional method for measuring the width of a rectangle.

FIG. 11 is a diagram showing a conventional method for measuring the width of a rectangle using an area.

Claims (4)

[Claims] 1. A center of gravity of a substantially rectangular image is obtained, a vertical line passing through the center of gravity and orthogonal to a scanning line is set, and a first line and a second line are drawn at an interval h orthogonal to the vertical line, The intersections of the first line and the substantially rectangle are A and B, the intersections of the second line and the substantially rectangle are C and D,
The area A1 of the quadrangle ABCD is calculated, and the intersection points A, B, C,
A perpendicular line is drawn from D to the other party's first and second lines, and the area enclosed by the perpendicular lines at both ends and the first and second lines is A0, and θ = tan ^-1 (A0-A1) / h ² ... (1) A dimension measuring method using an image, wherein θ represented by the equation (1) is an angle formed by a vertical line passing through a center of gravity of a substantially rectangular shape and indicating a direction of a long side. 2. A center of gravity of a substantially rectangular image is obtained, and an angle θ between a vertical line passing through the center of gravity and orthogonal to the scanning line and a center line passing through the center of gravity of the substantially rectangle and indicating the direction of the long side is determined by a predetermined method. Seeking,
Draw each line that makes an angle θ ± m Δθ (m is an integer) with the scanning line through the center of gravity, find the intersection of each line and the rectangle, find the length of the line segment between the intersections of each line, and remove the maximum and minimum values. A method for calculating the average value M of the remaining lengths, wherein Δθ is the estimated value of the average value M, and Δθ · M ′ / 2 is one pixel near the intersection of the substantially rectangular shape and the line segment. The size of
Where m is 2 sets of one or more pairs of irregularities representing the wavy side of a substantially rectangular side.
A dimension measuring method using an image, characterized in that it is defined so as to be included in a crossing range of m + 1 lines. 3. A center of gravity of a substantially rectangular image is obtained, and an angle θ between a vertical line passing through the center of gravity and orthogonal to the scanning line and a center line passing through the center of gravity of the substantially rectangle and indicating the direction of the long side is determined by a predetermined method. Seeking,
A reference line that passes through the center of gravity and forms an angle θ with the scanning line is obtained, and a total of n lines including this reference line are drawn in parallel with this reference line at a pitch δ, and the line between the intersections of these lines and the sides of the substantially rectangular shape. A method of obtaining a length of a minute and obtaining an average value N remaining after excluding a maximum value and a minimum value, wherein the pitch δ is set to about one pixel size, and n is a wave of a substantially rectangular side. A dimension measuring method using an image, characterized in that at least one set of concave and convex portions representing the above is defined so as to be included in a crossing range of n lines. 4. The coordinate point of a line segment that intersects with the substantially rectangular shape uses the center point of the pixel or the center point of four pixels arranged in a square, and when there is no intersection at this coordinate point position, A feature is that the length of the line segment is calculated with the center of the closest pixel or the center point of four pixels outside the corresponding line segment as the inside, with the line passing through the center of gravity and forming an angle θ with the scanning line as the inside. The method for measuring a dimension by an image according to claim 2 or 3.