Display device, head mount display, calibration method, calibration program and recording medium

A head mount display of optically transmissive type which displays additional information to a real environment visually recognized by a user, comprising:

• a position detecting unit which detects a specific position in the real environment;
• a calibration unit which obtains a correspondence between the specific position in the real environment and a specific position of the display device to compute calibration data for transforming from a first coordinate system of the position detecting unit at the specific position in the real environment to a second coordinate system of the display device;
• and
• a determining unit which determines a natural feature point suitable for computing the calibration data in the natural feature points existing in the real environment, based on a taken image taken by imaging the real environment by an imaging device,
• wherein the position detecting unit specifies the specific position in the real environment in the calibration unit by detecting the position of the natural feature point determined by the determining unit.

A calibration method executed by a display device of optically transmissive type which displays additional information to a real environment visually recognized by a user, comprising:

• a position detecting process which detects a specific position in the real environment;
• a calibration process which obtains a correspondence between the specific position in the real environment and a specific position of the display device to compute calibration data for transforming from a first coordinate system prescribed by the position detecting process at the specific position in the real environment to a second coordinate system of the display device;
• and
• a determining process which determines a natural feature point suitable for computing the calibration data in the natural feature points existing in the real environment, based on a taken image taken by imaging the real environment by an imaging device,
• wherein the position detecting process specifies the specific position in the real environment in the calibration process by detecting the position of the natural feature point determined by the determining process.

A calibration program stored in a non-transitory computer-readable medium and executed by a display device of optically transmissive type which includes a computer and which displays additional information to a real environment visually recognized by a user, making the computer function as:

• a position detecting unit which detects a specific position in the real environment;
• a calibration unit which obtains a correspondence between the specific position in the real environment and a specific position of the display device to compute calibration data for transforming from a first coordinate system of the position detecting unit at the specific position in the real environment to a second coordinate system of the display device;
• and
• a determining unit which determines a natural feature point suitable for computing the calibration data in the natural feature points existing in the real environment, based on a taken image taken by imaging the real environment by an imaging device,
• wherein the position detecting unit specifies the specific position in the real environment in the calibration unit by detecting the position of the natural feature point determined by the determining unit.