A Reliable Event-Driven Strategy for Real-Time Multiple Object Tracking Using Static Cameras

Algorithm 4

The tracking events algorithm.

Inputs data:

SSB: Set of N objects Segmented Bounded Boxes

SSB = {𝑅¹_seg,𝑅²_seg,…,𝑅^𝑁_seg}

KBB: Set of M objects EKF Bounded Boxes

KBB = {𝑅¹_kal,𝑅²_kal,…,𝑅^𝑀_kal}

AT: Set of M Appearance Templates

AT = {𝑇¹,𝑇²,…,𝑇^𝑀}

Algorithm

Defining Events for each Workstation:

 For each 𝑅^𝑥_segϵ SSB, test E₁, E₂, and E₃ in order

 E₁ :

   if 𝑅^𝑥_seg.not_matched (one in 𝐺_kal [])

   Then

    Trigger R₁

    go to OUT1

 E₂:

   if 𝑅^𝑥_seg.not_matched (any 𝑅^𝑖_kal ∈ KBB) AND

     𝑅^𝑥_seg.matched (one in 𝐺_kal [])

   Then

     Trigger R₂

     go to OUT1

 E₃:

   if size (𝑅^𝑥_seg) ≪ matched size (𝑅^𝑖_kal) AND

   𝑅^𝑥_seg.not_matched (one in 𝐺_kal [])

   Then

    Trigger R₃

    go to OUT1

 OUT1: Next

 For each 𝐑^𝐱_𝐤𝐚𝐥ϵ KBB, test E₄, E₅, and E₆ in order

 E₄:

   if 𝑅^𝑥_kal.Outside (FOV) AND

     𝑅^𝑥_kal.not_matched (any 𝑅^𝑖_seg𝜖 SBB)

   Then

     Trigger R₄

     go to OUT2

 E₅:

   if size (𝑅^𝑥_kal) < matched size (𝑅^𝑖_seg) AND

     𝑅^𝑥_kal.intersected_with (any 𝑅^𝑦_kal)

   Then

     Trigger R₅

     go to OUT2

 E₆:

   if 𝑅^𝑥_kal.matched (𝑅^𝑥_seg)

   Then

    Trigger R₆

    go to OUT2

 OUT2: Next

Events Responses:

Responses are done over:

SRM (Server Response Module) and WRM (Workstation

Response Module)

 R₁:

   new WRM.register (𝐺^𝑘)

   WRM.create_object_template (𝐺^𝑘)

   WRM.send_to_SRM (𝐺^𝑘)

   SRM.associate (𝐺_arrary []) get 𝐺_server []

   SRM.create_and_send_to_each_WRM (𝐺_kal [])

 R₂:

   new WRM.register (𝐺^𝑘)

   WRM.send_to_SRM (𝐺^𝑘)

   SRM.associate (𝐺_arrary[]) get 𝐺_server []

   SRM.create_and_send_to_each_WRM (𝐺_kal [])

 R₃:

   For all 𝑅^𝑦_seg

     if not 𝑅^𝑦_seg.matched_any_of (𝑅^𝑖_kal) AND 𝑅^𝑦_seg.near (𝑅^𝑥_seg)

     Then

       𝐺^𝑣 = WRM.get_object_of (𝑅^𝑥_seg)

       if 𝐺^𝑣.number_of_containted_objects == 1

       Then

         WRM.trigger_new_response (𝑅^𝑦_seg)

         WRM.build_history_of (𝑅^𝑦_seg)

       Else if 𝐺^𝑣.number_of_contained_objects > 1

       Then

         𝑅^𝑦_seg.associate_to_objects_in (𝐺^𝑣)

   Next

   WRM.trigger_stable_response (𝑅^𝑥_seg)

 R₄:

   WRM.stop_tracking (𝐺^𝑘)

 R₅:

   WRM.register_group (𝐺^𝑘) = 𝐺^𝑣 + 𝐺^𝑤

   WRM.announce_to_SRM (𝐺^𝑘)

   SRM.associate (𝐺_arrary[]) get 𝐺_server[]

   SRM.create_and_send_to_each_WRM (𝐺_kal [])

   if WRM.search(𝐺_server[],𝐺^𝑣,𝐺^𝑤) = = True

   Then

     WRM.split (𝐺^𝑘)

   Else

     WRM.give_EKF_position (𝐺^𝑣,𝐺^𝑤)

 R₆:

   WRM.track (𝐺^𝑘); WRM.update_EKF (𝐺^𝑘); WRM.update_template (𝑇^𝑥)

   WRM.send_to_SRM (𝐺^𝑘)

   SRM.associate (𝐺_arrary[]) get 𝐺_server[]

   SRM.create_and_send_to_each_WRM (𝐺_kal[])