Methods and apparatuses are provided for determining a pitch and yaw of an elongated interface object relative to a proximity sensitive surface. In one aspect, a proximity image is received having proximity image data from which it can be determined which areas of the proximity sensitive surface sensed the elongated interface object during a period of time. A proximity blob is identified in the proximity image and the proximity image is transformed using a plurality of different transformations to obtain a plurality of differently transformed proximity images. A plurality of features is determined for the identified blob in the transformed proximity images and the pitch of the elongated interface object relative to the proximity sensitive surface is determined based upon the determined features and a multi-dimensional heuristic regression model of the proximity sensitive surface; and a yaw is determined based upon the pitch.