Method, system and computer program for generating a database of pixel patterns includes obtaining images using an imaging system of mobile devices, each image including a pixel pattern, and determining a position of the mobile device using a positioning system at least partly situated on the mobile device when each image is obtained using the imaging system of the mobile device. Positional relationships between a size and/or angular orientation of the pattern of pixels and an associated determined position of the mobile device when the at least one image including the pattern of pixels was obtained are generated and enables retrieval of an estimation of the position of the mobile device upon input of another image including the pattern of pixels. The generated positional relationships between the size and/or angular orientation of the pattern of pixels and the associated determined position of the mobile device are stored in a database.