Map information update method

A map information update method for updating map information including one or more items of position information each associated with a corresponding one or more landmarks and one or more items of pose information each associated with a corresponding one of one or more keyframes,

• wherein each of the one or more keyframes is a captured image in which an image of at least one of the one or more landmarks is included,
• each of the one or more items of pose information includes information about a position and information about an orientation, and
• the map information update method comprises:
• obtaining one or more projection relationships each of which is a relationship of (i) a corresponding one of the one or more landmarks, (ii) a corresponding one of the one or more keyframes, and (iii) projection coordinate information corresponding to coordinates of a projection point on the corresponding one of the one or more keyframes at a time when the corresponding one of the one or more landmarks is projected onto the corresponding one of the one or more keyframes;
• for each of the one or more projection relationships, (1) obtaining reprojection error information based on (i) an item of position information which is associated with the corresponding one of the one or more landmarks included in the projection relationship among the one or more items of position information, (ii) an item of pose information which is associated with the corresponding one of the one or more keyframes included in the projection relationship among the one or more items of pose information, and (iii) the projection coordinate information included in the projection relationship, and (2) associating the reprojection error information with the projection relationship;
• for each of the one or more landmarks, (1) generating a first reprojection error information aggregate in which all items of reprojection error information associated with the landmark are aggregated, and (2) calculating a first sum value based on the all items of reprojection error information included in the first reprojection error information aggregate;
• for each of the one or more keyframes, (1) generating a second reprojection error information aggregate in which all items of reprojection error information associated with the keyframe are aggregated, and (2) calculating a second sum value based on the all items of reprojection error information included in the second reprojection error information aggregate;
• for each of the one or more landmarks, (1) inferring from the first sum value a position information update value which is an update value of an item of position information about the landmark among the one or more items of position information, and (2) updating the item of position information about the landmark using the position information update value;
• and
• for each of the one or more keyframes, (1) inferring from the second sum value a pose information update value which is an update value of an item of pose information about the keyframe among the one or more items of pose information, and (2) updating the item of pose information about the keyframe using the pose information update value.