Abstract: A measurement method including generating first restoration information representing a Euclidean restoration result for a first region of a screen that is a non-planar surface based on a first image that is one of an image input to a first apparatus including a first lens and having known internal parameters relating to the first lens and an image output from the first apparatus, and a second image that is one of an image input to a second apparatus including a second lens and having known internal parameters relating to the second lens and an image output from the second apparatus, generating second restoration information representing a projection restoration result for a second region of the screen based on a third image that is one of an image input to a third apparatus including a third lens and having unknown internal parameters relating to the third lens and an image output from the third apparatus, and the first image, generating a three-dimensional projective transformation matrix for transforming th

Abstract: A parameter determination method includes: determining N, N being a natural number greater than 1, first regions included in at least a part of a first image acquired by capturing a target with a first optical device positioned at a first position and whose internal parameters are known, or the first image projected from the first optical device; determining N second regions corresponding to the respective N first regions in a one-to-one manner in a second image acquired by capturing the target with a second optical device positioned at a second position different from the first and whose internal parameters are known; determining N homographies between the N first regions and the N second regions in a one-to-one manner; and determining at least one of a first parameter related to the second optical device and a second parameter related to the capturing target by decomposing each of the N homographies.

Abstract: A projector includes a first acquisition unit, a detection unit, a second acquisition unit, and a display control unit. The first acquisition unit acquires a captured image of a range containing a display surface by a camera. The detection unit detects a first bright point and a second bright point corresponding to reflected lights of a first light and a second light radiated substantially parallel to the display surface by a pointer from the captured image. When a distance between a position of the first bright point and a position of the second bright point is less than a first threshold, the second acquisition unit acquires a third position determined based on the first bright point and the second bright point. The display control unit displays a display image containing a drawn image by the pointer in the third position.

Abstract: A projector includes a first acquisition unit, a second acquisition unit, a first determination unit, and a display control unit. The first acquisition unit sequentially acquires a first captured image and a second captured image on a display surface. The second acquisition unit acquires a first brightness value and a first position of a bright point contained in the first captured image and a second brightness value and a second position of a bright point contained in the second captured image. The first determination unit determines whether the second brightness value is larger than the first brightness value by a first threshold or more and the second position is closer to a camera than the first position. The display control unit displays a display image containing a drawn image showing a drawn line by a pointer when a determination result is negative, and displays a display image not containing the drawn image when the determination result is positive.

Abstract: A projective transformation matrix determination method includes receiving a change instruction to change a positional relationship among four feature points in a situation in which a projector projects a first projection image showing the four feature points onto a first area, causing the projector to project a second projection image showing the four feature points onto the first area in response to the change instruction, and determining a projective transformation matrix based on the coordinates of the four feature points in the second projection image and the coordinates of the four feature points in a first captured image generated by capturing, with a camera, an image of the first area where the second projection image is projected, the projective transformation matrix associating a projector coordinate system which defining the coordinates in an image projected by the projector with a camera coordinate system defining the coordinates in an image generated by the camera.

Abstract: An annunciation method includes the steps of obtaining first position information as position information of a place where a first object is located, obtaining second position information as position information of a place where a second object is located, obtaining third position information as position information of a place where a third object is located, setting the first object and the second object as a first group when a distance between the first object and the second object calculated based on the first position information and the second position information is smaller than or equal to a first threshold value, obtaining fourth position information representing a position of the first group, and performing annunciation when a distance between the third object and the first group calculated based on the third position information and the fourth position information is smaller than a second threshold value.

Abstract: A projective transformation matrix determination method includes receiving a change instruction to change a positional relationship among four feature points in a situation in which a projector projects a first projection image showing the four feature points onto a first area, causing the projector to project a second projection image showing the four feature points onto the first area in response to the change instruction, and determining a projective transformation matrix based on the coordinates of the four feature points in the second projection image and the coordinates of the four feature points in a first captured image generated by capturing, with a camera, an image of the first area where the second projection image is projected, the projective transformation matrix associating a projector coordinate system which defining the coordinates in an image projected by the projector with a camera coordinate system defining the coordinates in an image generated by the camera.

Abstract: A projector includes an image projection section projecting an image on a projection surface, an imager capturing a surface image to produce a captured image, a controller causing the image projection section to project a calibration image and causing the imager to capture the projected calibration image, a computing section calculating conversion information for converting a position in the captured image into a position in the projection image based on the captured image as a result of the calibration image imaging, and a detector searching the projection image and detecting a pointing position at which a light emitting pen pointing at the projection surface has pointed based on the conversion information and captured image as a result of the light emitting pen imaging, and the computing section calculates a projection distance between the projector and projection surface based on the captured image as a result of the calibration image imaging.

Abstract: A display apparatus includes a display section that projects and displays an image on a display surface, an imaging section that captures an image of the display surface, a measurement section that measures the distance between the display surface and the display section, and a calibration processor that causes the display section to display a calibration image containing a position detection mark based on the distance measured by the measurement section, causes the imaging section to capture an image of the calibration image displayed on the display surface, and performs calibration that associates coordinates on the image with coordinates on the captured image captured by the imaging section based on the captured image.

Abstract: A projector includes an image projection section projecting an image on a projection surface, an imager capturing a surface image to produce a captured image, a controller causing the image projection section to project a calibration image and causing the imager to capture the projected calibration image, a computing section calculating conversion information for converting a position in the captured image into a position in the projection image based on the captured image as a result of the calibration image imaging, and a detector searching the projection image and detecting a pointing position at which a light emitting pen pointing at the projection surface has pointed based on the conversion information and captured image as a result of the light emitting pen imaging, and the computing section calculates a projection distance between the projector and projection surface based on the captured image as a result of the calibration image imaging.

Abstract: A display apparatus includes a display section that projects and displays an image on a display surface, an imaging section that captures an image of the display surface, a measurement section that measures the distance between the display surface and the display section, and a calibration processor that causes the display section to display a calibration image containing a position detection mark based on the distance measured by the measurement section, causes the imaging section to capture an image of the calibration image displayed on the display surface, and performs calibration that associates coordinates on the image with coordinates on the captured image captured by the imaging section based on the captured image.