Projection control device, marker detection method, and storage medium

1. A projection control device comprising:

a projection module configured to project a correcting image onto a projection target, the correcting image including an image position identifying marker which includes a first polygon and a second polygon positioned inside the first polygon and which is arranged in a predetermined position, and the correcting image being projected onto the projection target for pickup by an image pickup device,

wherein at least one of sides of the first polygon is non-parallel to sides of the second polygon, and

wherein the second polygon has as many vertices as the first polygon or has fewer vertices than the first polygon.

2. The projection control device according to claim 1 ,

wherein the first polygon has a quadrangular shape, and

wherein the second polygon has a triangular shape.

3. The projection control device according to claim 2 ,

wherein the first polygon is formed into a frame shape, and

wherein the second polygon is formed by being colored out in a color identical to a color of the first polygon.

4. The projection control device according to claim 3 , wherein another side of the first polygon which is different from the at least one side thereof is parallel to one of the sides of the second polygon.

5. The projection control device according to claim 2 , wherein another side of the first polygon which is different from the at least one side thereof is parallel to one of the sides of the second polygon.

6. The projection control device according to claim 1 ,

wherein the first polygon is formed into a frame shape, and

wherein the second polygon is formed by being colored out in a color identical to a color of the first polygon.

7. The projection control device according to claim 6 , wherein another side of the first polygon which is different from the at least one side thereof is parallel to one of the sides of the second polygon.

8. The projection control device according to claim 1 , wherein another side of the first polygon which is different from the at least one side thereof is parallel to one of the sides of the second polygon.

9. The projection control device according to claim 1 , further comprising:

a communication device that communicates with the image pickup device,

wherein the projection control device acquires, from the image pickup device via the communication device, a result of analyzing the correcting image.

10. A marker detection method comprising:

projecting a correcting image onto a projection target using a projection control device, the correcting image including an image position identifying marker which includes a first polygon and a second polygon positioned inside the first polygon and which is arranged in a predetermined position;

picking up a plurality of the correcting images projected onto the projection target using an image pickup device; and

causing the marker to be detected,

wherein at least one of sides of the first polygon is non-parallel to sides of the second polygon, and

wherein the second polygon has as many vertices as the first polygon or has fewer vertices than the first polygon.

11. The marker detection method according to claim 10 , wherein the causing the marker to be detected comprises:

extracting a contour of the correcting image picked up by the image pickup device;

extracting, when a contour of a first process target selected from the extracted contour has vertices corresponding in number to a predetermined first condition, a contour residing further inwards than the contour of the first process target;

obtaining, when a contour of a second process target selected from the inward contour has vertices corresponding in number to a predetermined second condition, a ratio of an area of the contour of the first process target to an area of the contour of the second process target; and

obtaining, when the ratio falls within a predetermined range, the contours of the first process target and the second process target as the marker.

12. A non-transitory storage medium readable by a computer, the storage medium storing a program which is executable to control the computer to execute processes comprising:

performing control to project a correcting image onto a projection target, the correcting image including an image position identifying marker which includes a first polygon and a second polygon positioned inside the first polygon and which is arranged in a predetermined position;

performing control to pick up a plurality of the correcting images projected onto the projection target; and

performing control to cause the marker to be detected,

wherein at least one of sides of the first polygon is non-parallel to sides of the second polygon, and

wherein the second polygon has as many vertices as the first polygon or has fewer vertices than the first polygon.

13. A marker detection method comprising:

projecting a correcting image having an image position identifying marker including a first polygon and a second polygon positioned inside the first polygon and arranged in a predetermined position using a projection control device, at least one of sides of the first polygon being non-parallel to sides of the second polygon;

picking up a plurality of the correcting images using an image pickup device; and

causing the marker to be detected,

wherein the causing the marker to be detected comprises:

extracting a contour of the correcting image picked up by the image pickup device;

extracting, when a contour of a first process target selected from the extracted contour has vertices corresponding in number to a predetermined first condition, a contour residing further inwards than the contour of the first process target;

obtaining, when a contour of a second process target selected from the inward contour has vertices corresponding in number to a predetermined second condition, a ratio of an area of the contour of the first process target to an area of the contour of the second process target; and

obtaining, when the ratio falls within a predetermined range, the contours of the first process target and the second process target as the marker.