Interactive projector and method of correcting Z-coordinate of the same
An interactive projector is provided with a projection section adapted to project an image on a screen surface, a detection section, and a correction section. The detection section detects presence or absence of contact of the pointing element with the screen surface based in a relationship between a difference between a Z-coordinate value of the pointing element and a Z-coordinate value of the screen surface, and a difference threshold value set in advance. The correction section corrects at least one of the Z-coordinate value of the screen surface, the Z-coordinate value of the pointing element, and the difference threshold value based on a history of the Z-coordinate value of the pointing element.
1. An interactive projector adapted to detect a position of a pointing element, comprising:
a projection section adapted to project an image on a screen surface; and
a processor programmed to:
detect a three-dimensional coordinate value of the pointing element;
detect presence or absence of contact of the pointing element with the screen surface based on a relationship between a difference between a Z-coordinate value of the pointing element and a Z-coordinate value of the screen surface, and a difference threshold value set in advance, a Z-coordinate being a coordinate in a direction of getting away from the screen surface;
update a history of Z-coordinate values of the pointing element, when the presence or absence of contact of the pointing element with the screen surface is detected; and
correct at least one of the Z-coordinate value of the screen surface, the Z-coordinate value of the pointing element, and the difference threshold value based on the updated history of Z-coordinate values of the pointing element.
2. The interactive projector according to claim 1 , further comprising: a plurality of cameras each adapted to image a projection range, in which the image is projected, in the screen surface, wherein the processor is further programmed to:
detect the three-dimensional coordinate value of the pointing element with triangulation using a plurality of images that include the pointing element taken by the plurality of cameras.
3. An interactive projector adapted to detect a position of a pointing element, comprising:
a projection section adapted to project an image on a screen surface; and
a processor programmed to:
detect a three-dimensional coordinate value of the pointing element;
detect presence or absence of contact of the pointing element with the screen surface based on a relationship between a difference between a Z-coordinate value of the pointing element and a Z-coordinate value of the screen surface, and a difference threshold value set in advance, a Z-coordinate being a coordinate in a direction of getting away from the screen surface; and
correct at least one of the Z-coordinate value of the screen surface, the Z-coordinate value of the pointing element, and the difference threshold value based on the a history of Z-coordinate values of the pointing element, wherein the processor is further programmed to: perform the correction based on a histogram of the historical Z-coordinate values of the pointing element.
4. The interactive projector according to claim 1 , wherein the processor is further programmed to: perform the correction based on a histogram of the historical Z-coordinate values of the pointing element.
5. The interactive projector according to claim 1 , wherein the processor is further programmed to: perform the correction in accordance with a magnitude relation between a minimum Z-coordinate value in the history of the Z-coordinate values of the pointing element and the Z-coordinate value of the screen surface.
6. The interactive projector according to claim 1 , wherein the processor is further configured to: perform the correction based on the history of the Z-coordinate values of the pointing element in a case in which a Z-direction speed of the pointing element is zero.
7. A method of correcting a Z coordinate of an interactive projector capable of detecting a position of a pointing element using a plurality of cameras each adapted to image a projection range, the method comprising:
detecting a three-dimensional coordinate value of the pointing element;
detecting presence or absence of contact of the pointing element with the screen surface based on a relationship between a difference between a Z-coordinate value of the pointing element and a Z-coordinate value of the screen surface, and a difference threshold value set in advance, a Z-coordinate being a coordinate in a direction of getting away from the screen surface;
updating a history of Z-coordinate values of the pointing element, when the presence or absence of contact of the pointing element with the screen surface is detected; and
correcting at least one of the Z-coordinate value of the screen surface, the Z-coordinate value of the pointing element, and the difference threshold value based on the updated history of Z-coordinate values of the pointing element.
8. The interactive projector according to claim 4 , wherein the processor is further programmed to: perform the correction in accordance with a magnitude relation between a Z-coordinate value representing a peak of the histogram of the historical Z-coordinate values of the pointing element and the Z-coordinate value of the screen surface.