Extraction of extraction information from scanning information of a surface for use with a database

A method for determining a position of a detection unit, comprising:

• acquiring scanning information from the detection unit, wherein the scanning information are a scan of a surface, and wherein the scanning information comprise information on an inherent feature of the surface, wherein the inherent feature of the surface comprises a plurality of sub-features;
• and
• extracting extraction information for the inherent feature from the scanning information;
• wherein extracting the extraction information further comprises, for each sub-feature of the plurality of sub-features, extracting a set of sub-extraction information and determining a descriptor for each sub-feature as part of the set of sub-extraction information;
• and
• determining a value from each set of sub-extraction information, the value being associated to an information content of the sub-feature associated with the set of sub-extraction information;
• and
• comparing each value to a threshold value;
• and
• selecting those sets of sub-extraction information whose associated sub-feature at least reaches the determined value of the threshold value;
• and
• performing matching, based on the determined descriptors of the selected sets of sub-extraction information, with a database, wherein the database stores descriptors for the plurality of sub-features of extraction information for a plurality of inherent features of the surface whose positions are known;
• and
• determining the position of the detection unit based on the matching.

A non-transitory digital storage medium having stored thereon a computer program for performing a method for determining a position of a detection unit, comprising:

• acquiring scanning information from the detection unit, wherein the scanning information are a scan of a surface, and wherein the scanning information comprise information on an inherent feature of the surface, wherein the inherent feature of the surface comprises a plurality of sub-features;
• and
• extracting extraction information for the inherent feature from the scanning information;
• wherein extracting the extraction information further comprises, for each sub-feature of the plurality of sub-features, extracting a set of sub-extraction information and determining a descriptor for each sub-feature as part of the set of sub-extraction information;
• and
• determining a value from each set of sub-extraction information, the value being associated to an information content of the sub-feature associated with the set of sub-extraction information;
• and
• comparing each value to a threshold value;
• and
• selecting those sets of sub-extraction information whose associated sub-feature at least reaches the determined value of the threshold value;
• and
• performing matching, based on the determined descriptors of the selected sets of sub-extraction information, with a database, wherein the database stores descriptors for the plurality of sub-features of extraction information for a plurality of inherent features of the surface whose positions are known;
• and
• determining the position of the detection unit based on the matching,
• when said computer program is run by a computer.