Measurement method, measurement device, and recording medium

1 . A measurement method executed by one or more processors, the measurement method comprising:

calculating three-dimensional coordinates of two or more points on a subject having a three-dimensional shape on the basis of a two-dimensional image of the subject, wherein the subject includes a surface defining a normal line having a direction perpendicular to the surface;

generating three-dimensional image data including the three-dimensional coordinates of the two or more points;

extracting, on the basis of the three-dimensional coordinates of the two or more points, shape features including a first shape feature in the three-dimensional shape of the subject and a second shape feature different from the first shape feature in the three-dimensional shape of the subject, the shape features being extracted on the basis of three-dimensional distances between the three-dimensional coordinates of the two or more points and a change in a direction of the normal line on the surface of a three-dimensional shape formed by the three-dimensional coordinates of the two or more points on the subject having the three-dimensional shape;

detecting a first feature region on the three-dimensional shape of the subject having the first shape feature and a second feature region on the three-dimensional shape of the subject having the second shape feature;

assigning each of the two or more points to one of the first feature region or the second feature region on the basis of the shape features;

controlling a display to display an image of the first feature region and the second feature region so that the first feature region and the second feature region are visually distinguished from each other;

selecting one of the first feature region and the second feature region as a selected region;

accepting a point on the subject through an input device after displaying the image of the first feature region and the second feature region;

generating point information indicating the accepted point;

invalidating the accepted point information when a point outside the selected region is accepted as the point on the subject accepted through the input device;

generating new point information indicating a point in the selected region; and

measuring a size of the subject on the basis of three-dimensional coordinates of at least two points of the two or more points on the subject including the new point in the selected region and other than the invalid point information.

2 . The measurement method according to claim 1 , further comprising:

selecting one of the first feature region and the second feature region as a selected region; and

validating the point information only when a point in the selected region is accepted as the point on the subject,

wherein the size of the subject is measured on the basis of the three-dimensional coordinates of the two or more points including the point indicated by the valid point information.

3 . The measurement method according to claim 2 ,

wherein a feature region that is included in the first feature region and the second feature region and includes a first point on the subject is selected as the selected region when the first point is accepted as the point on the subject,

wherein the size of the subject is measured on the basis of the three-dimensional coordinates of the two or more points including the first point and a second point in the selected region when the second point is accepted as the point on the subject, and

wherein the second point is different from the first point.

4 . The measurement method according to claim 2 ,

wherein, when a position on the image of the first feature region and the second feature region is accepted through the input device, a feature region that is included in the first feature region and the second feature region and corresponds to the accepted position is selected as the selected region.

5 . The measurement method according to claim 1 , further comprising:

controlling the display to display one of an image of the three-dimensional image data and the two-dimensional image with the image of the first feature region and the second feature region;

selecting one of the first feature region and the second feature region as a selected region;

controlling the display to display a mark on one of the image of the three-dimensional image data and the two-dimensional image; and

calculating a position at which the mark is displayed on the basis of information accepted through the input device,

wherein the position at which the mark is displayed is restricted to a position in a region corresponding to the selected region, and

wherein a point corresponding to the position of the mark is the point on the subject accepted through the input device.

6 . The measurement method according to claim 1 , further comprising:

selecting one of the first feature region and the second feature region as a selected region, controlling the display to display a mark on the image of the first feature region and the second feature region; and

calculating a position at which the mark is displayed on the basis of information accepted through the input device,

wherein the position at which the mark is displayed is restricted to a position in the selected region, and

wherein a point corresponding to the position of the mark is accepted as the point on the subject accepted through the input device.

7 . The measurement method according to claim 1 , further comprising:

controlling the display to display one of an image of the three-dimensional image data and the two-dimensional image with the image of the first feature region and the second feature region;

selecting one of the first feature region and the second feature region as a selected region;

controlling the display to display a mark on one of the image of the three-dimensional image data and the two-dimensional image; and

calculating a position at which the mark is displayed on the basis of information accepted through the input device,

wherein the size of the subject is measured on the basis of the three-dimensional coordinates of the two or more points including the point indicated by the point information when the mark is displayed in a region corresponding to the selected region and the point corresponding to the position of the mark is accepted as the point on the subject accepted through the input device, and

wherein a position at which the mark is displayed is changed to a position in the region corresponding to the selected region when the mark is displayed outside the region corresponding to the selected region and the point corresponding to the position of the mark is accepted as the point on the subject accepted through the input device.

8 . The measurement method according to claim 1 , further comprising:

selecting one of the first feature region and the second feature region as a selected region;

controlling the display to display a mark on the image of the first region and the second feature region; and

calculating a position at which the mark is displayed on the basis of information accepted through the input device,

wherein the size of the subject is measured on the basis of the three-dimensional coordinates of the two or more points including the point indicated by the point information when the mark is displayed in the selected region and the point corresponding to the position of the mark is accepted, and

wherein a position at which the mark is displayed is changed to a position in the selected region when the mark is displayed outside the selected region and the point corresponding to the position of the mark is accepted.

9 . The measurement method according to claim 1 , further comprising:

selecting one of the first feature region and the second feature region as a selected region,

wherein the selected region is displayed in a first color and a feature region that is included in the first feature region and the second feature region and is different from the selected region is displayed in a second color different from the first color.

10 . The measurement method according to claim 1 , further comprising:

selecting one of the first feature region and the second feature region as a selected region,

wherein only the selected region is displayed.

11 . The measurement method according to claim 1 , further comprising:

selecting one of the first feature region and the second feature region as a selected region,

wherein the selected region is highlighted when displaying the selected region.

12 . The measurement method according to claim 1 , further comprising:

detecting at least one of an edge and a step on the surface of the subject on the basis of the three-dimensional coordinates of the two or more points and the change in the direction of the normal line on the surface of the subject,

wherein extracting the shape features comprises extracting the shape features on the basis of the three-dimensional distances between the two or more points and the at least one of the edge and the step detected on the basis of the change in the direction of the normal line on the surface of the subject.

13 . A measurement method executed by one or more processors, the measurement method comprising:

calculating three-dimensional coordinates of two or more points on a subject having a three-dimensional shape on the basis of a two-dimensional image of the subject, wherein the subject includes a surface defining a normal line having a direction perpendicular to the surface;

generating three-dimensional image data including the three-dimensional coordinates of the two or more points;

extracting, on the basis of the three-dimensional coordinates of the two or more points, a shape feature in the three-dimensional shape of the subject, the shape features being extracted on the basis of three-dimensional distances between the three-dimensional coordinates of the two or more points and a change in a direction of the normal line on the surface of a three-dimensional shape formed by the three-dimensional coordinates of the two or more points on the subject having the three-dimensional shape;

detecting a feature region on the three-dimensional shape of the subject having the shape feature;

assigning at least one of the two or more points to the feature region on the basis of the shape feature;

controlling a display to display one of an image of the three-dimensional image data, the two-dimensional image, and an image of the feature region;

selecting one of the first feature region and the second feature region as a selected region;

accepting a point on the subject through an input device after displaying the one of the image of the three-dimensional image data, the two-dimensional image, and the image of the feature region;

generating point information indicating the accepted point;

invalidating the generated point information when a point outside the selected region is accepted as the point on the subject accepted through the input device;

generating new point information indicating a new point in the selected region; and

executing one of a first control and a second control,

wherein the point information is controlled in the first control so that the point information indicates a position in the feature region or a position on an edge of the feature region,

wherein a mark is displayed on one of the image of the three-dimensional image data, the two-dimensional image, and the image of the feature region in the second control,

wherein a position of the mark is restricted to a position in a region corresponding to the feature region, and

wherein the point corresponding to the position of the mark is accepted in the accepting the point on the subject through the input device; and

measuring a size of the subject on the basis of three-dimensional coordinates of at least two points of the two or more points on the subject including the new point in the selected region and other than the invalid point information.

14 . A measurement device comprising:

one or more processors configured to:

calculate three-dimensional coordinates of two or more points on a subject having a three-dimensional shape on the basis of a two-dimensional image of the subject, wherein the subject includes a surface defining a normal line having a direction perpendicular to the surface;

generate three-dimensional image data including the three-dimensional coordinates of the two or more points;

extract, on the basis of the three-dimensional coordinates of the two or more points, shape features including a first shape feature in the three-dimensional shape of the subject and a second shape feature different from the first shape feature in the three-dimensional shape of the subject, the shape features being extracted on the basis of three-dimensional distances between the three-dimensional coordinates of the two or more points and a change in a direction of the normal line on the surface of a three-dimensional shape formed by the three-dimensional coordinates of the two or more points on the subject having the three-dimensional shape;

detect a first feature region on the three-dimensional shape of the subject having the first shape feature and a second feature region on the three-dimensional shape of the subject having the second shape feature;

assign each of the two or more points to one of the first feature region or the second feature region on the basis of the shape features;

control a display to display an image of the first feature region and the second feature region so that the first feature region and the second feature region are visually distinguished from each other;

select one of the first feature region and the second feature region as a selected region;

accept a point on the subject through an input device after displaying the image of the first feature region and the second feature region;

generate point information indicating the accepted point; and

invalidate the generated point information when a point outside the selected region is accepted as the point on the subject accepted through the input device;

generate new point information indicating a new point in the selected region; and

measure a size of the subject on the basis of three-dimensional coordinates of at least two points of the two or more points on the subject including the new point in the selected region and other than the invalid point information.

15 . A non-transitory computer-readable recording medium storing a program causing a computer to at least execute:

calculating three-dimensional coordinates of two or more points on a subject having a three-dimensional shape on the basis of a two-dimensional image of the subject, wherein the subject includes a surface defining a normal line having a direction perpendicular to the surface;

generating three-dimensional image data including the three-dimensional coordinates of the two or more points;

extracting, on the basis of the three-dimensional coordinates of the two or more points, shape features including a first shape feature in the three-dimensional shape of the subject and a second shape feature different from the first shape feature in the three-dimensional shape of the subject, the shape features being extracted on the basis of three-dimensional distances between the three-dimensional coordinates of the two or more points and a change in a direction of the normal line on the surface of a three-dimensional shape formed by the three-dimensional coordinates of the two or more points on the subject having the three-dimensional shape;

detecting a first feature region on the three-dimensional shape of the subject having the first shape feature on the subject and a second feature region on the three-dimensional shape of the subject having the second shape feature;

assigning each of the two or more points to one of the first feature region or the second feature region on the basis of the shape features;

controlling a display to display an image of the first feature region and the second feature region so that the first feature region and the second feature region are visually distinguished from each other;

selecting one of the first feature region and the second feature region as a selected region;

accepting a point on the subject through an input device after displaying the image of the first feature region and the second feature region;

generating point information indicating the accepted point;

invalidating the accepted point information when a point outside the selected region is accepted as the point on the subject accepted through the input device;

generating new point information indicating a point in the selected region; and

measuring a size of the subject on the basis of three-dimensional coordinates of at least two points of the two or more points on the subject including the new point in the selected region and other then the invalid point information.