Sparse agent re-identification

A system, comprising:

• one or more processors;
• and
• a memory storing program instructions that, when executed by the one or more processors, cause the one or more processors to at least:
• determine that an agent at a first event area of a plurality of event areas within a materials handling facility is to be identified, wherein:
• the materials handling facility includes the plurality of event areas and at least one untracked area that separates each of the plurality of event areas;
• and
• each event area of the plurality of event areas includes one or more cameras;
• define a node graph that includes a plurality of nodes, each node of the plurality of nodes representative of a plurality of unlinked sub-session tracklets, wherein each sub-session tracklet includes at least a feature embedding representative of the agent and generated based on one or more images of the agent generated while the agent is in an event area of the plurality of event areas;
• define an edge between a first node of the node graph corresponding to a first sub-session tracklet of the first event area and a second node of the node graph corresponding to a second sub-session tracklet of a second event area;
• and
• associate the first sub-session tracklet with the second sub-session tracklet as corresponding to the agent.

A computer-implemented method, comprising:

• generating, for each of a plurality of agents located within a materials handling facility, one or more sub-session tracklets indicative of the agent while the agent is at an event area within the materials handling facility, wherein:
• the materials handling facility includes a plurality of event areas and at least one untracked area that separates each of the plurality of event areas;
• and
• each event area of the plurality of event areas includes one or more cameras;
• including each of the sub-session tracklets in an unlinked sub-session tracklet list;
• determining an agent at an exit event area of the materials handling facility;
• generating, for the agent, an exit tracklet indicative of the agent at the exit event area;
• defining, based at least in part on the unlinked sub-session tracklet list, a plurality of nodes of a node graph, each node of the plurality of nodes corresponding to a sub-session tracklet indicated on the unlinked sub-session tracklet list;
• defining an edge between a first node of the node graph corresponding to a first sub-session tracklet and a second node of the node graph corresponding to the exit tracklet;
• and
• associating the first sub-session tracklet with an agent session generated for the agent.