Extendable tracking by line auto-calibration

A method for auto-calibrating a line feature within a real environment, comprising:

• (a) identifying a first image projection of a line feature in a first image of an environment viewed from a first camera pose;
• (b) identifying a second image projection of the line feature in a second image of the environment viewed from a second camera pose;
• and
• (c) calculating four variable line feature parameters that define the identified line feature in a local coordinate system.

Computer-readable media containing instructions executable by a computer that, when loaded and executed on a computer, estimate a camera pose from which an image of a real environment is viewed, by:

• (a) identifying a line feature within the image;
• (b) identifying values for each of four variable parameters that define the line feature in a local coordinated system;
• (c) estimating values for each of a plurality of parameters for the camera pose;
• and
• (d) solving a system of equations that involves the four variable parameters and the camera pose parameters by inserting the identified values for each of the four variable parameters and the estimated values for the plurality of parameters for the camera pose.

Computer-readable media containing instructions executable by a computer that, when loaded and executed on a computer, auto-calibrate a line feature within a real environment, by:

• (a) identifying a first image projection of a line feature in a first image of an environment viewed from a first camera pose;
• (b) identifying a second image projection of the line feature in a second image of the environment viewed from a second camera pose;
• and
• (c) calculating four variable line feature parameters that define the identified line feature in a local coordinate system.