Apparatus and methods for clustering and matching feature descriptors

A method by at least one processor, the method comprising:

• applying a first clustering process to a plurality of descriptors associated with a geographical location to determine a number of descriptor clusters;
• applying a second clustering process to the number of descriptor clusters to determine a descriptor cluster center for each of the number of descriptor clusters;
• generating descriptor cluster data characterizing a similarity between the plurality of descriptors and the descriptor cluster centers;
• and
• storing the descriptor cluster data in a data repository.

An apparatus comprising:

• a non-transitory, machine-readable storage medium storing instructions;
• and
• at least one processor coupled to the non-transitory, machine-readable storage medium, the at least one processor being configured to execute the instructions to:
• generate an image descriptor based on an image;
• receive descriptor cluster data, wherein the descriptor cluster data characterizes a similarity between a plurality of descriptors and a plurality of descriptor cluster centers;
• determine at least one of the plurality of descriptor cluster centers based on the image descriptor and the descriptor cluster data;
• and
• determine a position based on the at least one of the plurality of descriptor cluster centers.