Position measurement method, position measurement device, and program

A non-transitory recording medium containing a program for running the following steps to a computer, the steps comprising:

• an initial value calculating step for calculating initial values of exterior orientation parameters, which are a photographing position and a photographing posture in an initial image;
• an exterior orientation parameter-calculating step for calculating exterior orientation parameters, based on known points in a moving image which follows the initial image, or characteristic points in which three-dimensional coordinates are already calculated;
• an exterior orientation parameter correcting step for correcting the exterior orientation parameters calculated in the exterior orientation parameter-calculating step;
• a bundle-adjusting step for simultaneously adjusting a bundle of the exterior orientation parameters of one or more images and the three-dimensional coordinates of the characteristic points, based on the exterior orientation parameters corrected by the exterior orientation parameter correcting step;
• a three-dimensional coordinate calculating step for calculating three-dimensional coordinates of characteristic points subsequently detected in an area in which the density of the characteristic points is decreased, based on the exterior orientation parameters adjusted bundle thereof;
• and
• a repeating step for repeating processing from the exterior orientation parameter-calculating step to the three-dimensional coordinate calculating step until the image becomes a final image,
• wherein the exterior orientation parameter correcting step corrects the exterior orientation parameters, based on difference between photographing timing of an image and obtaining timing of a photographing position measured by a position measuring unit, wherein the exterior orientation parameters are obtained by the photographing position measured by the position measuring unit at the obtaining timing.

A position measurement device comprising:

• a camera that obtains a moving image that is photographed by relatively shifting a photographing section and a photographed object incrementally;
• a position measuring unit that measures a photographing position of a camera from an outside;
• a posture measuring unit that measures photographing posture of the camera from the outside;
• and
• a computer processing unit that inputs the photographing position measured by the position measuring unit, and the photographing posture measured by the posture measuring unit and comprising a central processing unit (CPU) and a memory device storing position measurement programs,
• wherein the central processing unit (CPU) reads and executes the position measurement programs to perform operations comprising:
• (a) calculating initial values of exterior orientation parameters, which are a photographing position and a photographing posture in an initial image;
• (b) calculating exterior orientation parameters, based on known points in a moving image which follows the initial image, or characteristic points in which three-dimensional coordinates are already calculated;
• (c) correcting the calculated exterior orientation parameters, based on difference between photographing timing of the image and obtaining timing of the photographing position measured by the position measuring unit and the photographing posture measured by the posture measuring unit, wherein the exterior orientation parameters are obtained by the photographing position measured by the position measuring unit at the obtaining timing;
• (d) simultaneously adjusting a bundle of the exterior orientation parameters of one or more images and the three-dimensional coordinates of the characteristic points, based on the exterior orientation parameters corrected by the exterior orientation parameter correcting section;
• (e) calculating three-dimensional coordinates of characteristic points subsequently detected in an area in which the density of the characteristic points is decreased, based on the exterior orientation parameters adjusted bundle thereof;
• and
• repeating the operations (b) to (e) until the image becomes a final image.

A position measurement method comprising:

• an initial value calculating step for calculating initial values of exterior orientation parameters, which are a photographing position and a photographing posture in an initial image;
• an exterior orientation parameter-calculating step for calculating exterior orientation parameters, based on known points in a moving image which follows the initial image, or characteristic points in which three-dimensional coordinates are already calculated;
• an exterior orientation parameter correcting step for correcting the exterior orientation parameters calculated in the exterior orientation parameter-calculating step;
• a bundle-adjusting step for simultaneously adjusting a bundle of the exterior orientation parameters of one or more images and the three-dimensional coordinates of the characteristic points, based on the exterior orientation parameters corrected by the exterior orientation parameter correcting step;
• a three-dimensional coordinate calculating step for calculating three-dimensional coordinates of characteristic points subsequently detected in an area in which the density of the characteristic points is decreased, based on the exterior orientation parameters adjusted bundle thereof;
• and
• a repeating step for repeating processing from the exterior orientation parameter-calculating step to the three-dimensional coordinate calculating step until the image becomes a final image,
• wherein the exterior orientation parameter correcting step corrects the exterior orientation parameters, based on difference between photographing timing of an image and obtaining timing of a photographing posture measured by a posture measuring unit, wherein the exterior orientation parameters are obtained by the photographing posture measured by the posture measuring unit at the obtaining timing.