Measurement device, method of operating measurement device, and recording medium

1. A measurement device comprising:

an image sensor configured to acquire a first image of a subject; and

a controller configured to:

display at least one of the first image and a second image based on the first image;

read out measurement mode information indicating a measurement mode from a recording medium having the measurement mode information recorded therein;

set a plurality of reference designation points in one of the displayed first image and the displayed second image on the basis of a first position designated by a user in one of the displayed first image and the displayed second image;

calculate one of a reference line and a reference plane on the basis of the plurality of reference designation points, the reference line and the reference plane being used in the measurement mode indicated by the measurement mode information;

set a measurement point in one of the displayed first image and the displayed second image, on the basis of a second position designated by the user in one of the displayed first image and the displayed second image;

execute measurement of the subject;

calculate a plurality of reference points leading to higher reliability of a measurement result instead of the plurality of reference designation points, on the basis of one of the first image and the second image in which the measurement point is set, the plurality of reference designation points, the measurement mode, and the measurement point,

calculate one of a new reference line and a new reference plane on the basis of the plurality of reference points, and

execute the measurement on the basis of one of the new reference line and the new reference plane, the measurement point, and the measurement mode.

2. The measurement device according to claim 1 , wherein the controller is configured to calculate a portion of the plurality of reference points using a point, located at the same position as that of the reference designation point included in the plurality of reference designation points, as the reference point.

3. The measurement device according to claim 1 , wherein the controller is configured to calculate the plurality of reference points such that distances between the plurality of reference points increase.

4. The measurement device according to claim 1 ,

wherein the plurality of reference points are at least three reference points, and

the controller is configured to calculate the at least three reference points such that an area of a polygon with vertices at the at least three reference points increases.

5. The measurement device according to claim 1 , wherein the controller is configured to calculate the plurality of reference points such that one of a first intersection point and a second intersection point comes close to a centroid of the plurality of reference points, the first intersection point being an intersection point of a perpendicular line from the measurement point to the new reference line with the new reference line, and the second intersection point being an intersection point of a perpendicular line from the measurement point to the new reference plane with the new reference plane.

6. The measurement device according to claim 1 , wherein the controller is configured to calculate the plurality of reference points such that a degree to which the new reference line approximates an end of the subject becomes higher.

7. The measurement device according to claim 1 , wherein the controller is configured to calculate the plurality of reference points such that a degree to which the new reference plane approximates a surface of the subject becomes higher.

8. The measurement device according to claim 1 , wherein the controller is configured to calculate at least one reference point included in the plurality of reference points such that distances between the plurality of reference points become larger than distances between the plurality of reference designation points.

9. The measurement device according to claim 1 ,

wherein the plurality of reference designation points are at least three reference designation points,

the plurality of reference points are at least three reference points,

the controller is configured to calculate the at least three reference points such that a first area becomes larger than a second area,

the first area is an area of a polygon with vertices at the at least three reference points, and

the second area is an area of a polygon with vertices at the at least three reference designation points.

10. The measurement device according to claim 1 ,

wherein the controller is configured to calculate the plurality of reference points such that a first distance becomes smaller than a second distance,

the first distance is a distance between one of a first intersection point and a second intersection point and a centroid of the plurality of reference points, the first intersection point being an intersection point of a perpendicular line from the measurement point to the new reference line with the new reference line, and the second intersection point being an intersection point of a perpendicular line from the measurement point to the new reference plane with the new reference plane, and

the second distance is a distance between one of a third intersection point and a fourth intersection point and a centroid of the plurality of reference designation points, the third intersection point being an intersection point of a perpendicular line from the measurement point to the reference line with the reference line, and the fourth intersection point being an intersection point of a perpendicular line from the measurement point to the reference plane with the reference plane.

11. The measurement device according to claim 1 ,

wherein the controller is configured to calculate the plurality of reference points such that a first degree becomes higher than a second degree,

the first degree is a degree to which one of the new reference line and the new reference plane determined on the basis of the plurality of reference points approximates a surface of the subject, and

the second degree is a degree to which one of the reference line and the reference plane determined on the basis of the plurality of reference designation points approximates the surface of the subject.

12. The measurement device according to claim 1 , wherein the controller is configured to calculate at least one reference point included in the plurality of reference points such that a position of the at least one reference point satisfies a criterion according to characteristics of the measurement mode indicated by the measurement mode information.

13. The measurement device according to claim 12 , wherein the controller is configured to:

set a plurality of temporary reference points in one of the displayed first image and the displayed second image,

select combinations, each including at least two temporary reference points included in the plurality of temporary reference points,

calculate an evaluation value indicating a degree to which the at least two temporary reference points included in the combination are suitable for the criterion, for each combination, and

in a case where a first degree indicated by the evaluation value of a first combination is higher than a second degree indicated by the evaluation value of a second combination, set at least one of the at least two temporary reference points included in the first combination as the reference point.

14. The measurement device according to claim 1 , wherein the controller is configured to to display the plurality of reference points on at least one of the displayed first image and the displayed second image.

15. The measurement device according to claim 1 , wherein the controller is configured to display one of the reference line and the reference plane determined on the basis of the plurality of reference points on at least one of the displayed first image and the displayed second image.

16. The measurement device according to claim 1 , wherein the controller is configured to display the plurality of reference points and the plurality of reference designation points on at least one of the displayed first image and the displayed second image.

17. The measurement device according to claim 1 , wherein the controller is configured to display the new reference line determined on the basis of the plurality of reference points and the reference line determined on the basis of the plurality of reference designation points on at least one of displayed the first image and the displayed second image.

18. The measurement device according to claim 1 , wherein the controller is configured to display the new reference plane determined on the basis of the plurality of reference points and the reference plane determined on the basis of the plurality of reference designation points on at least one of the displayed first image and the displayed second image.

19. A method of operating a measurement device, the method comprising:

acquiring a first image of a subject;

displaying at least one of the first image and a second image based on the first image;

reading out measurement mode information indicating a measurement mode from a recording medium having the measurement mode information recorded therein;

setting a plurality of reference designation points in one of the displayed first image and the displayed second image, on the basis of a first position designated by a user in one of the displayed first image and the displayed second image;

calculating one of a reference line and a reference plane on the basis of the plurality of reference designation points, the reference line and the reference plane being used in the measurement mode indicated by the measurement mode information;

setting a measurement point in one of the displayed first image and the displayed second image, on the basis of a second position designated by the user in one of the displayed first image and the displayed second image;

calculating a plurality of reference points leading to higher reliability of a measurement result instead of the plurality of reference designation points, on the basis of one of the first image and the second image in which the measurement point is set, the plurality of reference designation points, the measurement mode, and the measurement point;

calculating one of a new reference line and a new reference plane on the basis of the plurality of reference points; and

executing measurement of the subject on the basis of one of the new reference line and the new reference plane, the measurement point, and the measurement mode.

20. A computer-readable non-transitory recording medium having a program recorded therein, the program causing a computer to:

acquire a first image of a subject;

display at least one of the first image and a second image based on the first image;

read out measurement mode information indicating a measurement mode from a recording medium having the measurement mode information recorded therein;

set a plurality of reference designation points in one of the displayed first image and the displayed second image, on the basis of a first position designated by a user in one of the displayed first image and the displayed second image;

calculate one of a reference line and a reference plane on the basis of the plurality of reference designation points, the reference line and the reference plane being used in the measurement mode indicated by the measurement mode information;

set a measurement point in one of the displayed first image and the displayed second image, on the basis of a second position designated by the user in one of the displayed first image and the displayed second image;

calculate a plurality of reference points leading to higher reliability of a measurement result instead of the plurality of reference designation points, on the basis of one of the first image and the second image in which the measurement point is set, the plurality of reference designation points, the measurement mode, and the measurement point;

calculate one of a new reference line and a new reference plane on the basis of the plurality of reference points; and

execute measurement of the subject on the basis of one of the new reference line and the new reference plane, the measurement point, and the measurement mode.