Abstract: Various implementations disclosed herein include devices, systems, and methods that determine the relative positioning (e.g., offset) between a mobile electronic device and a visual marker. In some implementations, the determined relative positioning and a known position of the visual marker are used to determine a position (e.g., geo coordinates) of the mobile electronic device that is more accurate than existing techniques. In some implementations, the determined relative positioning is used with a position of the mobile electronic device to crowd source the stored position of the visual marker. In some implementations, the determined relative positioning and a position of the visual marker are used to determine a position of an object detected in an image by the mobile electronic device. In some implementations at an electronic device having a processor, locally-determined locations of a visual marker are received from mobile electronic devices that scan a visual marker.