1. A method of image-based positioning comprising: (A) performing image-recording of a scene by using an image capturing device; (B) performing an initial image analysis to determine suitability of recorded images; (C) obtaining a set of depth data of said scene by pre-surveying said scene; (D) using scene understanding techniques to discard unsuitable regions of images of broadly defined features for tracking, wherein said broadly defined features are selected from the group consisting of: points; representations of regions; and representations of contours; performing object recognition; inferring an object category from at least one cluster of neighboring features; determining the suitability of the inferred object category for surface tracking; and (E) tracking movement of said image capturing device by analyzing a set of suitably recorded images.