Specifying method, specifying system which accurately specifies the correspondence relation between the projector coordinate system and the camera coordinate system

1. A specifying method comprising:

determining whether an camera that images a projection object onto which a projection image is projected from a projector is fixed;

sequentially projecting images belonging to a first group onto the projection object from the projector when determining that the camera is not fixed;

sequentially projecting images belonging to a second group onto the projection object from the projector when determining that the camera is fixed;

imaging the projection object with the camera to generate a captured image in a state in which the images belonging to the first group or the images belonging to the second group are projected; and

specifying, based on an image projected onto the projection object from the projector and the captured image by the camera, a correspondence relation between a position on the image projected onto the projection object and a position on the captured image.

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

detecting an amount of change of a position of the camera from first time to second time;

determining that the camera is not fixed when the amount of change is equal to or larger than a threshold; and

determining that the camera is fixed when the amount of change is smaller than the threshold.

3. The specifying method according to claim 1 , further comprising:

detecting an amount of change of speed of the camera from first time to second time;

determining that the camera is not fixed when the amount of change is equal to or larger than a threshold; and

determining that the camera is fixed when the amount of change is smaller than the threshold.

4. The specifying method according to claim 3 , further comprising:

detecting first acceleration, which is acceleration of the camera at the first time, and second acceleration, which is acceleration of the camera at the second time; and

setting a sum of the first acceleration and the second acceleration as the amount of change of the speed of the camera.

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

detecting acceleration of the camera in each of first time, second time, third time, and fourth time;

determining that the camera is not fixed when intensity at a peak of a spectrum in a frequency domain, converted from a distribution of an acceleration of the camera in a time domain from the first time to the fourth time, is equal to or larger than a threshold; and

determining that the camera is fixed when the intensity at the peak of the spectrum is smaller than the threshold.

6. The specifying method according to claim 1 , further comprising

determining, based on an information indicating whether the camera is fixed input by a user, whether the camera is fixed.

7. The specifying method according to claim 1 , wherein a number of images of the first group is smaller than a number of images of the second group.

8. The specifying method according to claim 1 , wherein the images of the first group are the images of patterns different from one another, and the images of the first group are the images obtained by adding markers for positioning of the patterns to the images of the patterns different from one another.

9. A specifying system comprising:

a projector;

a camera; and

at least one processor executes:

determining whether the camera is fixed;

causing the projector to sequentially project images belonging to a first group onto a projection object when determining that the camera is not fixed;

causing the projector to sequentially project images belonging to a second group onto the projection object when determining that the camera is fixed;

causing the camera to image the projection object to generate a captured image in a state in which the images belonging to the first group or the images belonging to the second group are projected; and

specifying, based on an image projected onto the projection object from the projector and the captured image by the camera, a correspondence relation between a position on the image projected onto the projection object and a position on the captured image.

10. A non-transitory computer-readable storage medium storing a program, the program causing a computer to execute:

determining whether a camera that images a projection object onto which a projection image is projected from a projector is fixed;

causing the projector to sequentially project images belonging to a first group onto the projection object when determining that the camera is not fixed;

causing the projector to sequentially project images belonging to a second group onto the projection object when determining that the camera is fixed;

causing the camera to image the projection object to generate a captured image in a state in which the images belonging to the first group or the images belonging to the second group are projected; and

specifying, based on an image projected on the projection object from the projector and the captured image by the camera, a correspondence relation between a position on the image projected onto the projection object and a position on the captured image.