HMD Calibration with Direct Geometric Modeling

摘要

An optical see-through (OST) head-mounted display (HMD) uses a calibration matrix having a fixed sub-set of adjustable parameters within all its parameters. Initial values for the calibration matrix are based on a model head. A predefined set of incremental adjustment values is provided for each adjustable parameter. During calibration, the calibration matrix is cycled through its predefined incremental parameter changes, and a virtual object is projected for each incremental change. The resultant projected virtual object is aligned to a reference real object, and the projected virtual object having the best alignment is identified. The setting values of the calibration matrix that resulted in the best aligned virtual object are deemed the final calibration matrix to be used with the OST HMD.

主权项

1. A calibration method of an optical see-through (OST) head-mounted display (HMD) of an augmented reality (AR) system, comprising:
providing a real target object in a scene where the OST HMD is to be used, said real target object being of known dimensions, location and orientation within said scene; defining a default calibration matrix set based on a predefined head model; generating a virtual object representation of the real target object using the default calibration matrix set, and projecting a view of the virtual object; centrally aligning the projected view of virtual object onto the real target object as much as possible; cycling through a predefined number of incremental changes in at least one predefined parameter within said default calibration matrix set; for each incremental change of the predefined parameter, generating and projecting a new virtual object, re-aligning the new virtual object to the real target object, and comparing the current re-alignment of the current new virtual object to a previous alignment of a previously projected virtual object; identifying the projected virtual object having the best alignment with the real target object and designated it a calibrated virtual object; and setting the OST HMD to use the calibration matrix set with the value of the predefined parameter that corresponds to the calibrated virtual object.