1. Field
The present disclosure relates generally to augmented reality (AR) devices, e.g., AR eyeglasses, having optical see-through head mounted displays (HMD) and eye tracking capability, and more particularly, to automatic calibration of the scene camera of such AR devices. AR is a technology in which a user's view of the real world is enhanced with additional information generated from a computer model. The enhancements may include labels, 3D rendered models, or shading and illumination changes. AR allows a user to work with and examine the physical real world, while receiving additional information about the objects in it.
2. Background
AR devices typically include an optical see-through HMD and one or more user input mechanisms that allow users to simultaneously see and interact with their surroundings while interacting with applications, such as e-mail and media players. User input mechanisms may include one or more of gesture recognition technology, and eye tracking technology. AR devices also allow a user to view real-world scenes through optical see-through HMDs together with two-dimensional (2D) or three-dimensional (3D) augmented reality content displayed on the HMDs.
It is difficult for the user of an AR device with optical see-through HMDs to see 3D augmented reality that is well aligned with markers or objects in the real world for each eye. In order to see a well-aligned augmented reality on each eye, a scene camera of the AR device needs to be calibrated for each eye of the user. Existing scene camera calibration processes are very cumbersome. Users typically have to go through a 12-step calibration process for each eye to be able to see a well-aligned augmented reality. After initial calibration, further calibration may be necessary if the user repositions the AR device on his face
Furthermore, since the eye distance between a user's eye and the HMD varies among users, the calibrated data, also referred to as “projection matrix,” for one user does not work well for other users. Accordingly, while one user of an AR device may see 3D augmented reality aligned with the real world object, another user of the same AR device may not have the same experience. As such, each individual user of an AR device needs to go through the cumbersome calibration steps for experiencing AR properly aligned with real world. In the best case, relying on pre-existing calibration data, users still need 4-step calibration process.