JP2005204724A - Endoscope apparatus for measurement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope for a measurement, which improves the measuring accuracy to a defect amount of a blade of a curve edge by approximating a lost edge by a curve and finding a distance between a virtual point on a virtual curve and a specified measurement point. <P>SOLUTION: The endoscope for the measurement is provided with an electronic endoscope with an image pickup means; a control device having an image processing means generating an image signal based on an image pickup signal, and a measurement processing means inputting the image signal and performing the measurement of an object to be measured; and a display device displaying an output image. The measurement processing means is provided with a means of specifying a part of an outline of the measurement object as a reference edge, a means of specifying a point on the object to be measured as a measurement point, a means of approximating the reference edge as a virtual curve complemented with a parametric curve, and a defect width computing means finding the distance between the virtual point as a specific point on the virtual curve and the measurement point. This constitution can improve the measuring accuracy to the defect amount of the blade of the curve edge. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a measurement endoscope apparatus that measures the depth of a chipped portion, in particular, based on an image obtained by imaging a measurement object in a device.

  In a gas turbine mainly used in an aircraft, the edge of a turbine blade or a compressor blade may be chipped due to entry of foreign matter or the like. The dimension of the depth of the chip of the blade is one of the conditions for judging the replacement of the blade, and the inspection is extremely important.

In such a situation, in a conventional measuring endoscope, a measurement method for obtaining a distance between a straight line and a point is used for measuring the depth of chipping of a turbine blade or a compressor blade (for example, According to such a method, the edge is approximated by a straight line, and the distance from the lost edge to the depth of the chip is measured.
Japanese Patent Laid-Open No. 10-248806

  However, the conventional method only measures the distance from the lost edge to the depth of the chip by approximating the chip of the edge with a straight line, so if the edge is close to a straight line or a straight line, Although accuracy can be expected, there has been a problem that a measurement error of a chip amount becomes large in a blade having a curved edge which has been increasing in recent years.

  Accordingly, the present invention has been made in view of the above-described problems, and approximates a lost edge with a curve, and obtains a distance between a virtual point on a virtual curve and a designated measurement point, An object of the present invention is to provide a measurement endoscope that improves the measurement accuracy with respect to the amount of chipped blades at curved edges.

The present invention proposes the following means in order to solve the above-described problems.
According to a first aspect of the present invention, there is provided an electronic endoscope provided with an imaging unit that images a measurement object, and an image that is connected to the electronic endoscope and generates a video signal based on an imaging signal from the imaging unit. A control device comprising a processing means and a measurement processing means for inputting the video signal generated by the image processing means and measuring the measurement object, and an output output based on an instruction from the control device A display device for displaying an image, wherein the measurement processing means designates a part of the outline of the measurement object as a reference edge, and designates a certain point on the measurement object as a measurement point Measurement point designating means, edge approximating means for approximating the reference edge as a virtual curve interpolated with a parametric curve, a virtual point that is a specific point on the virtual curve, and a missing width for obtaining a distance between the measurement points With computing means Proposes endoscope apparatus for measurement, characterized by.

  According to the present invention, a part of the contour line of the measurement object is designated as the reference edge by the operation of the reference edge designating means, and a certain point on the measurement object is designated as the measurement point by the operation of the measurement point designating means. Is done. Then, the operation of the edge approximation means approximates the designated reference edge as a virtual curve interpolated with a parametric curve, and the operation of the missing width calculation means causes a virtual point that is a specific point on the approximated virtual curve; The distance to the measurement point is determined.

The invention according to claim 2 is directed to the endoscope apparatus for measurement according to claim 1, wherein the reference edge designating unit designates the reference edge by designating a sequence of three or more points as a reference point sequence. An endoscope apparatus for measurement that is characterized by the above is proposed.
The invention according to claim 3 further includes virtual curve shape changing means for appropriately changing the shape of the virtual curve in the edge approximating means in the measurement endoscope apparatus according to claim 1 or claim 2. A characteristic measuring endoscope device is proposed.

  The invention according to claim 4 has a projection processing means for converting spatial coordinates into image coordinates for the measuring endoscope apparatus according to any one of claims 1 to 3, wherein the display means includes: Proposed is a measuring endoscope apparatus characterized by superimposing and displaying a projected virtual curve obtained by processing the virtual curve by the projection processing means and an image of the measurement object imaged by the imaging means. .

  According to a fifth aspect of the present invention, in the measurement endoscope apparatus according to any one of the first to third aspects, the display means includes the virtual point and the measurement object captured by the imaging means. An endoscope apparatus for measurement has been proposed in which an image is superimposed and displayed based on the image coordinates of the virtual point obtained by the projection processing means.

  The invention according to claim 6 is the measurement endoscope apparatus according to any one of claims 1 to 3, wherein the virtual point has a minimum distance from the measurement point on the virtual curve. A measuring endoscope apparatus characterized by the above is proposed.

  The invention according to claim 7 is the measurement endoscope apparatus according to any one of claims 1 to 3, wherein the edge approximation means increases the number of points of the reference point sequence by one. An endoscope apparatus for measurement is proposed in which the shape of the virtual curve is corrected from the coordinates of the added point and the virtual curve.

The invention according to claim 8 is the measurement endoscope apparatus according to any one of claims 1 to 3, further comprising parametric curve selection means for selecting the parametric curve. An endoscopic device is proposed.
According to this invention, the parametric curve optimum for the edge shape can be freely selected by the operation of the parametric curve selection means.

The invention according to claim 9 proposes an endoscope apparatus for measurement characterized by having an edge extraction means for extracting an edge of the measurement object with respect to the endoscope apparatus for measurement according to claim 1. doing.
According to the present invention, by operating the edge extraction means, for example, the edge can be automatically detected accurately, and the depth of the chipped portion can be measured more easily.

According to the present invention, the lost edge is approximated by a curve, and the distance between the virtual point on the virtual curve and the designated measurement point is obtained, thereby improving the measurement accuracy for the missing amount of the blade of the curve edge. There is an effect that can be.
In addition, since the shape of the virtual curve can be changed while displaying the image obtained by capturing the edge portion and the virtual curve superimposed, there is an effect that the measurement accuracy can be improved by visual adjustment.
Furthermore, since a means for selecting a virtual curve to be used is provided, there is an effect that an accurate virtual curve corresponding to the shape of the edge to be measured can be used.

  Hereinafter, an endoscope apparatus for measurement according to an embodiment of the present invention will be described in detail with reference to FIGS.

  As shown in FIG. 1, an endoscope apparatus for measurement according to an embodiment of the present invention includes an endoscope 2, a control unit 3, a remote controller 4, a liquid crystal monitor 5, and a face mount display (FMD) 6. And an FMD adapter 6a, optical adapters 7a, 7b, 7c, an endoscope unit 8, a camera control unit 9, and a control unit 10.

  The endoscope 2 includes an elongated insertion portion 20, and the insertion portion 20 includes a hard distal end portion 21, for example, a bending portion 22 that can be bent vertically and horizontally, and a flexible tube portion 23 having flexibility. Various optical adapters such as a stereo optical adapter 7a, 7b having two observation fields or a normal observation optical adapter 7c having one observation field can be attached to and detached from the distal end portion 21 by, for example, screwing. It is configured.

  The control unit 3 includes an endoscope unit 8, a camera control unit (hereinafter referred to as CCU) 9 that is an image processing unit, and a control unit 10 that is a control device. The proximal end portion is connected to the endoscope unit 8.

The endoscope unit 8 includes a light source device that supplies illumination light necessary for observation, and a bending device that bends the bending portion 22 that constitutes the insertion portion 20.
The CCU 9 inputs an imaging signal output from the solid-state imaging device 2 a built in the distal end portion 21 of the insertion unit 20, converts this into a video signal such as an NTSC signal, and supplies it to the control unit 10. .

  The control unit 10 includes an audio signal processing circuit 11, a video signal processing circuit 12, a ROM 13, a RAM 14, a PC card interface (hereinafter referred to as PC card I / F) 15, and a USB interface (hereinafter referred to as USB). 16, an RS-232C interface (hereinafter referred to as RS-232C I / F) 17, and the like, and a measurement processing unit 18.

The audio signal processing circuit 11 collects sound generated by the microphone 34 and is recorded on a generated recording medium such as a memory card, an audio signal obtained by reproducing the recording medium such as a memory card, or the measurement processing unit 18. The audio signal generated by is supplied.
The video signal processing circuit 12 is an operation menu for generating a video signal from the CCU 9 under the control of the measurement processing unit 18 in order to display a composite image obtained by synthesizing the endoscopic image supplied from the CCU 9 and a graphic operation menu. And a predetermined process for displaying on the screen of the LCD 5 is supplied to the LCD 5.

  The PC card I / F 15 can freely attach and detach a memory card which is a recording medium such as the PCMCIA memory card 32 and the compact flash (registered trademark) memory card 33. By mounting the memory card, the control processing information 18 and the data such as the image information stored in the memory card are taken in or the control processing information and the data such as the data are stored in the memory card. Can be recorded.

  The USB I / F 16 is an interface for electrically connecting the control unit 3 and the personal computer 31. By electrically connecting the control unit 3 and the personal computer 31 via the USB I / F 16, various instructions such as an instruction for displaying an endoscopic image on the personal computer 31 side and image processing during measurement are provided. Control can be performed, and various processing information and data can be input / output between the control unit 3 and the personal computer 31.

  The RS-232C I / F 17 is connected to the CCU 9 and the endoscope unit 8 and the remote controller 4 that performs control and operation instructions thereof. The operation of the remote controller 4 controls the operation of the CCU 9 and the endoscope unit 8. Performs communication for control.

Further, as shown in FIG. 2, the measurement processing unit 18 includes a reference edge designating unit 41, a measurement point designating unit 42, a control unit 43, an edge approximating unit 44, a virtual curve shape changing unit 45, and a missing width. The calculation unit 46, a parametric curve selection unit 47, an edge extraction unit 48, and a projection processing unit 49 are configured.
The reference edge designating unit 41 inputs three or more reference points designated by the edge using the remote controller 4 or the like on the image of the measurement target displayed on the liquid crystal monitor 5 or the face mount display 6. Then, the spatial coordinates of these reference points are output to the control unit 43.

  The measurement point designating unit 42 inputs an instructed measurement point on the image of the measurement object displayed on the liquid crystal monitor 5 or the face mount display 6 using the remote controller 4 or the like, and the space of this measurement point. The coordinates are output to the control unit 43.

  The control unit 43 includes a storage unit (not shown), and converts the image coordinates of the reference points and measurement points input from the reference edge designating unit 41 or the measurement point designating unit 42 into spatial coordinates and stores them. Further, in response to an instruction from the virtual curve shape changing unit 45 or the parametric curve selecting unit 47, a desired virtual curve is output to the edge approximating unit 44, and virtual curve shape change information is input. Further, the calculation result is input from the missing width calculation unit 46, and such information, the shape of the virtual curve, and the like are output to the video signal processing circuit 12.

  The edge approximation unit 44 approximates the reference edge with the selected desired virtual curve. Specifically, a predetermined calculation is performed according to a parameter given from the control unit 43, and the result is output to the control unit 43 as a coefficient of a virtual curve.

The virtual curve shape changing unit 45 outputs change information of the selected virtual curve shape to the control unit 43 according to the user's selection.
The missing width calculation unit 46 obtains a virtual point having a minimum distance from the measurement point on the virtual curve from the spatial coordinates of the determined measurement point, calculates the missing width of the measurement object, and outputs the result to the control unit Output to 43.

The parametric curve selection unit 47 outputs the selected parametric curve information to the control unit 43 according to the user's selection.
The projection processing unit 49 converts the spatial coordinates of the reference point, measurement point, virtual point, and virtual curve into image coordinates, and outputs this information to the control unit 43.

Next, a processing procedure in the measurement endoscope apparatus according to the first embodiment will be described with reference to FIGS. 4 to 19.
In the present embodiment, the measurement target object is an object in which the shape of the part where the chip has occurred is originally a curve, as shown in FIG. In order to measure the depth of chipping of such a measurement object, as shown in FIG. 5, first, the distal end portion 21 of the endoscope 2 is operated while viewing the display on the liquid crystal monitor 5 or the face mount display 6. Then, the missing part of the measurement object is displayed.

  Next, in a state in which the missing portion of the measurement object is displayed, as shown in FIG. 4, three reference points (R [0], R [1], R [2] in the figure) are provided at both ends of the edge. ) Is designated (step 101). When the three reference points are designated (step 201), as shown in FIG. 13, the reference edge designation unit 41 calculates the designated three spatial coordinates and outputs the calculation result to the control unit 43. (Step 202). The calculated spatial coordinates may be directly output to the projection processing unit 49 without using the control unit 43.

  The calculation of the spatial coordinates is performed by searching for a point corresponding to the designated reference point on the reference image displayed on the liquid crystal monitor 5 or the face mount display 6, and using the principle of triangulation, a space such as Equation 1 is obtained. This is done by calculating the coordinates. This calculation method is the same as that described in Patent Document 1.

  Next, the edge approximation unit 44 inputs the spatial coordinates of the three reference points calculated from the control unit 43, and obtains a quadratic curve passing through these three points as a virtual curve according to the procedure of FIG. The formula of the virtual curve is as shown in Equation 2 with t as a parameter.

Substituting the coordinates of the three points R [0] to [2] of Equation 1 into Equation 2, t in R [0] is 0, and t in R [1] is p (where 0 <p < 1) The coefficient a [0] to a [2], b [0] to b [2], and c [0] to c [2] of the simultaneous equations of Formula 2 are obtained by setting t in R2 to 1 (step) 301 to step 303).
Here, p is a shape factor, and the initial value is calculated with p = 0.5.

Specifically, the calculation of the coefficients of the simultaneous equations will be described below with reference to FIG. 15 taking x as an example.
That is, the simultaneous equations are replaced by the matrices shown in Equations 3 to 5 below, and the ternary simultaneous equations of Equation 6 are solved.

  Then, A is obtained using the inverse matrix of T as T '(steps 401 to 404). By the same procedure, b [0] to b [2] and c [0] to c [2] can be obtained.

  Based on the obtained curve, the projection on the input image is obtained by the projection processing unit 49, and the obtained image coordinates are output to the liquid crystal monitor 5 or the face mount display 6 as image information via the control unit 43. . And this is superimposed and displayed on the input surface image of a measurement object.

  When the shape of the virtual curve output to the liquid crystal monitor 5 or the face mount display 6 is not appropriate (step 103), the reference point can be corrected or the shape factor can be changed. That is, as shown in FIG. 5, when the correction function is selected from the menu, the operator is allowed to select whether to change the shape factor or the reference point position.

  When the operator selects the shape factor change (step 105), the shape factor is changed between 0 and 1 by directly inputting a value or moving the slide bar displayed on the screen, and the processing returns to step 102. If correction of the reference point position is selected (step 104), the reference point can be moved. When the correction of the reference point position is completed, the process returns to step 101. These processes are executed by the virtual curve shape changing unit 45 and the control unit 43.

  In addition, the change of the shape of the parabola accompanying the change of the shape factor is as shown in FIGS. 7 shows the shape of a parabola when p = 0.2, FIG. 8 shows the shape of a parabola when p = 0.3, and FIG. 9 shows the shape of a parabola when p = 0.4. FIG. 10 shows the shape of the parabola when p = 0.5, and FIG. 11 shows the shape of the parabola when p = 0.6.

According to this example, when the value of p is close to 1, the curve shape between two points from the top of the three reference points approaches a straight line, and the curvature of the curve between the two points from the bottom increases. I understand.
Therefore, if the value of p is manipulated while confirming the edge shape of the measurement object with an image, a virtual curve approximating the edge shape can be set.

  Next, when the measurement point designating unit 42 inputs information on the measurement point (step 301), the corresponding point of the measurement point is searched on the image of the measurement object, and the spatial coordinates of the measurement point are expressed by the formula 7 using the principle of triangulation. Is calculated and output to the control unit 43 (step 106, step 502).

The missing width detection unit 46 receives information on the virtual curve and the spatial coordinates of the measurement point from the control unit 43, obtains a distance from the measurement point at a point on the virtual curve (step 601), and then determines the distance. The minimum virtual point is obtained within the range of Equation 8 (step 602). The obtained spatial coordinates of the virtual point are input to the projection processing unit 49, and the projection onto the image is calculated (step 603). Then, the projection of the calculated virtual point is drawn on the image (step 604).
T_MIN and T_MAX are preset maximum and minimum values of t.

  Next, the calculated virtual point is represented by Equation 9.

  Then, the distance between the obtained virtual point and the measurement point is obtained by Equation 10 (step 107).

  Further, the obtained distance is displayed on the liquid crystal monitor 5 or the face mount display 6 as a measurement result (step 108).

  In the present embodiment, the number of reference point sequences is four compared to the first embodiment. In this embodiment, the p-value is optimized using the fourth spatial coordinate. As a result, the correction of the virtual curve is sufficient only by correcting the reference point position.

  Optimization is performed as follows. First, similarly to the virtual point input process in the first embodiment, the point on the virtual curve that minimizes the distance L from the fourth reference point is obtained. Next, t is optimized by using t ′ which is the value of t at that point and setting p = t ′.

Here, if L does not become smaller than the predetermined value L_TOL, an imaginary curve that smoothly connects all the reference points cannot be obtained. Is included. Accordingly, in this case, a warning message “Please correct the reference point position” is displayed on the liquid crystal monitor 5 or the face mount display 6 to prompt the operator to correct the reference point position.
As a result, if the position of the reference point is appropriately specified, a suitable virtual curve can be obtained without taking the effort of changing the shape factor by the operator.

  The present embodiment includes selection means for selecting which virtual curve approximates the edge of the measurement object in advance by setting from the menu. Thereby, when it is determined whether the edge shape of the measurement object is set by a specific curve, the edge shape can be estimated more accurately.

Here, if the selected virtual curve is a quadratic expression, the processing is the same as in the first embodiment. If the selected virtual curve is a cubic equation, the processing is as follows.
That is, in this case, the reference point sequence is four points as shown in Equation 11.

  At this time, the equation of the virtual curve is expressed by Equation 12 with t as a parameter.

Therefore, the coordinates of four points from R [0] to R [3] are substituted into this equation, t at R [0] is 0, and t at R [1] is p1 (where 0 <p1 <1) , R [2] is set to p1 + (1−p1) * p2 (where 0 <p2 <1), and t in R [3] is set to 1 to solve the simultaneous equations, and a [0] to a [3 ], B [0] to b [3] and c [0] to c [3] are obtained.
Here, p1 and p2 are shape factors, and the initial values are calculated with p1 = 0.3 and p2 = 0.5.

The shape factor is changed by inputting two numbers or by moving two slide bars (see FIG. 5). If the selected expression is a cubic spline, N points (N> 3) are designated as reference points.
For i = 0.1,..., N−1, the parameter t [j] at the reference point R [j] is expressed by the following equation 13 using the distance between the reference points. When a set of I = 0,..., N−1 is given, the section of Expression 15 is expressed as Expression 16.

  However, A, B, C, and D are Formula 17, and y2 [j] is the solution of the simultaneous equations of Formula 18. Note that tan (a) represents the tangent of a, and PI represents the circumference. Further, pl and p2 are shape factors, and -1 <p1 <1, -1 <p2 <1. The initial values of the two shape factors are set to 0, and the change of the shape factor is designated by inputting two numbers or moving two slide bars. Then, for each of x, y, and z, f is obtained using R [0] to R [N-1] to obtain an equation of a virtual curve.

  In this embodiment, a virtual point position correction function is added. When this function is selected from the menu, a slide bar similar to the shape factor change is displayed, and the virtual point moves on the virtual curve in response to the operation of the slide bar. A measurement result is obtained and displayed from the coordinates of the changed virtual point and the coordinates of the measurement point.

In the above-described embodiments described so far, when edges remain on both sides of the chipped portion, accurate measurement can be performed, but the virtual point is a point on the virtual curve closest to the measurement point. Therefore, when applied to a measurement object with missing corners as shown in FIG. 6, the result may be inaccurate.
However, according to the present embodiment, an accurate result can be obtained even when applied to a measurement object with missing corners.

  As shown in FIG. 3, the present embodiment has a configuration in which an edge extraction unit 48, an edge selection unit 50, a differential filter selection unit 51, and an edge detection threshold value changing unit 52 are added to FIG. In this embodiment, when an edge extracted by the edge extraction unit 48 or a plurality of edges are extracted, a virtual curve is applied to the edge selected from the edges to obtain a virtual curve. .

Hereinafter, specific processing will be described with reference to FIGS. 18 and 19.
First, a differential filter is applied to the observation image capturing the measurement object (step 801), and pixels whose differential value is equal to or greater than a threshold value are extracted (step 802). The filter to be applied can be selected from a plurality of filters such as a Sobel filter, a Roverts filter, and a Prewltt filter. When applying the differential filter, the edge direction is also calculated at the same time.

  For example, when the Sobel filter is used, the differential value g (i, j) of the coordinates i and j is expressed by Equation 19 with the pixel value being f, and the edge direction t is expressed by Equation 20. However, atan (a) represents the inverse function (arctangent) of tangent of a.

  Next, thinning processing is performed to remove noise (step 803). At this time, since a plurality of edges are usually detected, each detected edge is labeled (step 804). The amount of change in the edge direction is obtained for each point on the edge, and the edge is divided at the point where the second derivative becomes 0, that is, the inflection point, and another label is attached (steps 701 and 805).

  Then, the edge is selected (step 702), and the spatial coordinates of the point on the edge are obtained (step 703). Next, a Hough transform is applied to the selected edge to fit a quadratic curve (step 704). The projection of the obtained curve onto the input image is obtained, and is displayed superimposed on the input image. If the operator determines that there is no problem with the displayed curve, the measurement point input is performed. If there is a problem, the type of the differential filter or the threshold value for edge detection is changed to perform edge extraction (step 701) again (step 705). ).

  When the measurement point is input on the reference image, the corresponding point of the measurement point is searched on the reference image, and the spatial coordinates of the measurement point are calculated as shown in Equation 21 based on the principle of triangulation (step 706).

  When the spatial coordinates of the measurement point are calculated, a virtual point having a minimum distance from the measurement point at a point on the virtual curve is obtained (step 707). Then, the calculated virtual point is represented by Formula 22.

  Next, the distance between the calculated virtual point and the measurement point is determined based on Equation 23 (step 708). Then, the projection of the virtual point on the input image is obtained and displayed superimposed on the observation image, and the obtained distance is displayed as a measurement result (step 709).

  Therefore, in the above-described embodiments described so far, there is a problem that the measurement result becomes inaccurate when the input of the reference point is inaccurate. However, in this embodiment, the edge detection is automatically performed. Therefore, it is not necessary to specify the reference point precisely, and the load on the operator is greatly reduced. In addition, the possibility of a decrease in accuracy due to an erroneous operation by the operator can be reduced.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and includes design changes and the like within a scope not departing from the gist of the present invention. It is.

It is a block diagram of the endoscope apparatus for measurement which concerns on this invention. It is a block diagram of a measurement process part. It is a block diagram of a measurement process part. It is the figure which showed the relationship between the missing part of a measurement target object, a reference point, a measurement point, and a virtual point. It is the figure which showed the measurement object, menu, etc. which are displayed on a display part. It is the figure which showed the relationship between the chip | tip part of a measurement target object, and a reference point, a measurement point, and a virtual point when a corner | angular part of a measurement target object has a chip | tip. It is the figure which showed the shape of the virtual curve when operating a shape change coefficient. It is the figure which showed the shape of the virtual curve when operating a shape change coefficient. It is the figure which showed the shape of the virtual curve when operating a shape change coefficient. It is the figure which showed the shape of the virtual curve when operating a shape change coefficient. It is the figure which showed the shape of the virtual curve when operating a shape change coefficient. FIG. 3 is a diagram illustrating a processing flow of Example 1. It is a processing flowchart when a reference point is input. It is a processing flow figure when a measurement point is input. It is a processing flow figure at the time of calculating a virtual curve. It is a processing flow figure at the time of calculating a coefficient. It is a processing flowchart when a reference point is input. FIG. 10 is a diagram illustrating a processing flow of Example 5. It is a processing flow figure at the time of performing edge extraction.

Explanation of symbols

2 ... endoscope, 3 ... control unit, 4 ... remote controller, 5 ... liquid crystal monitor, 6 ... face mount display (FMD), 6a ... FMD adapter, 7a, 7b 7c: Optical adapter, 8: Endoscope unit, 9: Camera control unit, 10: Control unit, 11: Audio signal processing circuit, 12: Video signal processing circuit, 13 ... ROM, 14 ... RAM, 15 ... PC card interface, 16 ... USB interface, 17 ... RS-232C interface, 18 ... measurement processing unit, 41 ... reference edge Designating part, 42 ... Measuring point designating part, 43 ... Control part, 44 ... Edge approximating part, 45 ... Virtual curve shape changing part, 46 ... Missing width calculating part, 7 ... parametric curve selection unit, 48 ... edge extraction unit, 49 ... projection section,

Claims (9)

An electronic endoscope provided with an imaging means for imaging a measurement object;
An image processing means connected to the electronic endoscope for generating a video signal based on an imaging signal from the imaging means;
A control device including a video signal generated by the image processing means and a measurement processing means for performing measurement processing of the measurement object;
A display device that displays an output image output based on an instruction of the control device;
A reference edge designating unit for designating a part of the outline of the measurement object as a reference edge by the measurement processing unit;
Measurement point designating means for designating a point on the measurement object as a measurement point;
Edge approximating means for approximating the reference edge as a virtual curve interpolated with a parametric curve;
An endoscope apparatus for measurement, comprising: a virtual point which is a specific point on the virtual curve; and a missing width calculation means for obtaining a distance between the measurement point and the virtual point.   2. The measuring endoscope apparatus according to claim 1, wherein the reference edge designating unit designates the reference edge by designating a sequence of three or more points as a reference point sequence.   3. The measuring endoscope apparatus according to claim 1, further comprising virtual curve shape changing means for appropriately changing the shape of the virtual curve in the edge approximating means. Having projection processing means for converting spatial coordinates into image coordinates;
2. The display unit according to claim 1, wherein the display unit superimposes a projected virtual curve obtained by processing the virtual curve by the projection processing unit and an image of the measurement object captured by the imaging unit. An endoscope apparatus for measurement described in any one of 3 above.   The display means superimposes and displays the virtual point and the image of the measurement object imaged by the imaging means based on the image coordinates of the virtual point obtained by the projection processing means. An endoscope apparatus for measurement according to any one of claims 1 to 4.   The measurement endoscope apparatus according to any one of claims 1 to 5, wherein the virtual point is a point having a minimum distance from the measurement point on the virtual curve.   The said edge approximation means corrects the shape of the virtual curve from the coordinates of the added point and the virtual curve when the number of points in the reference point sequence is increased by one. An endoscope apparatus for measurement described in any one of 3 above.   4. The measurement endoscope apparatus according to claim 1, further comprising parametric curve selection means for selecting the parametric curve. The measurement endoscope apparatus according to claim 1, further comprising an edge extraction unit configured to extract an edge of the measurement object.

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