ARToolKit is based on a basic corner detection approach with a fast pose estimation algorithm. We discuss more precisely of this algorithm in this page. In complement, we discuss on the accuracy of ARToolKit and the limitation of the actual camera calibration utility.

The next figures summarises the principle of the algorithm.

a. Original image	b. Thresholded image	c. Connected components
d. Contours	e. Extracted marker edges and corners	f. Fitted square