=Paper= {{Paper |id=Vol-3813/paper13 |storemode=property |title=Introducing Multiagent Systems for AV Visual Introducing Multiagent Systems for AV Visual Perception Sub-tasks: A proof-of-concept implementation for bounding-box improvement |pdfUrl=https://ceur-ws.org/Vol-3813/13.pdf |volume=Vol-3813 |authors=Alaa Daoud,Corentin Bunel,Maxime Guériau |dblpUrl=https://dblp.org/rec/conf/att/DaoudBG24 }} ==Introducing Multiagent Systems for AV Visual Introducing Multiagent Systems for AV Visual Perception Sub-tasks: A proof-of-concept implementation for bounding-box improvement== https://ceur-ws.org/Vol-3813/13.pdf
                         Introducing Multiagent Systems to AV Visual Perception
                         Sub-tasks: A proof-of-concept implementation for
                         bounding-box improvement
                         Alaa Daoud1 , Corentin Bunel1 and Maxime Guériau1
                         1
                          INSA Rouen Normandie, Univ Rouen Normandie, Univ Le Havre Normandie, Normandie Univ, LITIS UR 4108, F-76000 Rouen,
                         France


                                     Abstract
                                      Object detection is a pivotal task in computer vision, with applications spanning from autonomous driving to
                                      surveillance. Traditionally, methods like Non-Maximum Suppression (NMS) and its variants have been used
                                      to refine object detection outputs. Fusing predictions from different object detection models using confidence
                                      scores to average overlapping bounding boxes from multiple detection models has demonstrated superior
                                      performance over conventional methods. In this work, we employ multiple agents, each responsible for handling
                                      individual bounding boxes, to generate an improved fused prediction. This agent-based adaptation aims to
                                      leverage decentralized processing to potentially increase the system’s efficiency and adaptability across various
                                      object detection scenarios, particularly in autonomous vehicle (AV) perception systems. We develop two distinct
                                      behaviors for the bounding box agents: one replicating the state-of-the-art Weighted Boxes Fusion (WBF) method
                                      in a decentralized manner, and the other introducing competitive behavior where agents interact based on
                                      Intersection over Union (IoU) and confidence values. We evaluate the performance of our approach using the
                                      COCO dataset, demonstrating the flexibility and potential of integrating MAS into object detection workflows
                                      including those for AV perception systems.

                                      Keywords
                                     Autonomous driving, perception systems, bounding-box refinement, Multiagent Systems




                         1. Introduction
                         Autonomous vehicles and intelligent transport systems depend on advanced computer vision tech-
                         nologies, with object detection being a critical task. This enables vehicles to recognize and respond
                         to surrounding objects effectively, with region proposal identifying potential object locations early in
                         the detection process, crucial for timely responses in autonomous driving [1]. Traditional techniques
                         like Non-Maximum Suppression (NMS) often struggle to balance precision and recall, especially in
                         dynamic environments. Solovyev et al. [2] introduced Weighted Boxes Fusion (WBF), using confidence
                         scores to average overlapping bounding boxes from multiple detection models, demonstrating superior
                         performance over conventional methods.
                            The integration of Multiagent Systems (MAS) into object detection workflows offers new perspectives
                         to address traditional challenges [3, 4]. MAS provide dynamic and adaptable decision-making capabilities,
                         enhancing autonomous vehicles’ ability to handle complex, unpredictable road conditions. MAS support
                         distributed and adaptive processing [5], complementing modern GPU-based computer vision. By
                         distributing tasks across agents, MAS enhances system flexibility and resilience, especially in dynamic
                         environments like autonomous driving or video surveillance [6, 7, 8]. Each agent manages a subset of
                         tasks, improving resilience to errors [9, 10].
                            MAS can adjust strategies based on scenarios [11, 12], adapting parameters for bounding box fusion
                         based on context, scene complexity, or environmental changes [13]. Agents operate independently on
                         different hardware, optimizing processing power and allowing system scalability [14]. Local decisions
                         are combined through a global process, enhancing accuracy [15]. MAS can continually learn from
                          13th International Workshop on Agents in Traffic and Transportation (ATT 2024) held in conjunction with ECAI 2024
                          $ alaa.daoud@insa-rouen.fr (A. Daoud); corentin.bunel@insa-rouen.fr (C. Bunel); maxime.gueriau@insa-rouen.fr
                          (M. Guériau)
                           0000-0002-3640-327X (A. Daoud); 0000-0001-6637-9795 (C. Bunel); 0000-0002-8742-6623 (M. Guériau)
                                     © 2024 Copyright for this paper by its authors. Use permitted under Creative Commons License Attribution 4.0 International (CC BY 4.0).


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Workshop      ISSN 1613-0073
Proceedings
their environment and from the interactions between agents [16]. This potential for adaptive learning
motivates the agentification approach, as it opens the possibility for future enhancements. By achieving
an agentified method, we can later integrate learning capabilities to further improve adaptability
and performance in evolving object detection scenarios. Agent-based approaches are well-suited for
integrating diverse models and data sources [17], which is essential for the ensemble approaches used
in WBF where predictions from different models are combined.
   Agentifying output refinement methods such as NMS or WBF involves assigning individual agents to
handle specific bounding boxes, enabling dynamic adjustment based on individual box characteristics.
This approach addresses real-time processing requirements and improves scalability and fault tolerance
by decentralizing the decision-making process [18, 19, 20]. In this work, we aim to design and implement
a proof-of-concept system integrating MASs into the process of improving bounding boxes in object
detection. We will develop two behaviors for the bounding box agents: one replicating the state-of-
the-art Weighted Boxes Fusion (WBF) method in a decentralized manner, and the other introducing
competitive behavior where agents interact based on Intersection over Union (IoU) and confidence
values. Finally, we will deploy the system and assess its performance using the COCO dataset, testing
various levels of competition and cooperation between agents. The remainder of this paper is structured
as follows: Section 2 presents the related work in object detection, multiagent systems, and their
integration. Section 3 details the system architecture and design principles of the AWBF method.
Section 4 describes the implementation of the proof-of-concept system and the development of agent
behaviors. Section 5 discusses the experimental setup and evaluation using the COCO dataset. Section
6 presents the results and analysis of the experimental evaluation. Section 7 concludes the paper with a
summary of findings and future work directions.


2. Related Work
Object detection is a fundamental task in computer vision, critical for intelligent transportation systems
(ITS) applications such as autonomous driving, traffic monitoring, and surveillance. The integration
of MASs into object detection workflows offers significant potential to enhance system efficiency,
robustness, and adaptability. This section reviews recent advancements in object detection techniques
relevant to the ITS, with a focus on bounding box fusion and the role of MASs.

2.1. Bounding Box Improvement Techniques
Wang et al. (2019) presented the Multi-Stage Complementary Fusion (MCF3D) network, an end-to-
end architecture for 3D object detection that integrates LiDAR and RGB data. This network employs
attention mechanisms and prior knowledge to achieve state-of-the-art results, enhancing the detection
accuracy necessary for autonomous driving applications [21].
   Qian et al. (2020) proposed an improved object detection method for remote sensing images, incor-
porating a novel bounding box regression loss and a multi-level features fusion module. This method
enhances the precision of object localization, which is crucial for applications such as traffic monitoring
and vehicle detection [22].
   Solovyev et al. (2021) introduced the Weighted Boxes Fusion (WBF) method, which averages over-
lapping bounding boxes from multiple detection models using confidence scores. This approach
demonstrated superior performance over traditional techniques, highlighting the effectiveness of fusion
methods in improving object detection accuracy [2]. This method is particularly relevant for ITS
applications where robust and accurate object detection is paramount for safety and efficiency.
   Zhang and Wu (2022) proposed a multi-view feature adaptive fusion framework that enhances 3D
object detection by optimizing depth feature fusion and loss function design. This approach improves
the regression accuracy of bounding boxes, which is essential for ITS applications where precise object
localization is critical [23].
   Liu et al. (2023) developed the Fusion network by Box Matching (FBMNet) for multi-modal 3D
detection. This method aligns features at the bounding box level, providing stability in challenging
scenarios such as asynchronous sensors and misaligned sensor placements, common issues in ITS
applications [24].

2.2. Multiagent Systems in Object Detection
Introducing MAS to object detection and computer vision systems is not a new idea. For example
Choksuriwong et al. (2005) developed a MAS for image understanding that localizes and recognizes
objects using a distributed system implemented on a cluster computer. This approach leverages invariant
features and supervised classification to improve object recognition accuracy, which is vital for traffic
monitoring systems [25]. However, the application of MAS in these areas has decreased recently with
the advancements in machine learning techniques and their improved performance in handling object
detection tasks. Despite this shift, some researchers have continued to explore the potential of MAS in
object detection through various approaches.
   Jiang et al. (2019) proposed a multi-agent deep reinforcement learning (MADRL) approach for
multi-object tracking, using YOLO V3 for object detection and Independent Q-Learners (IQL) for policy
learning. This method achieves better performance in precision, accuracy, and robustness compared
to other state-of-the-art methods, which is particularly beneficial for real-time traffic monitoring and
surveillance [26].
   Fekir and Benamrane (2015) introduced a MAS for boundary detection and object tracking using
active contours and multi-resolution treatment. This system improves object boundary detection and
tracking through cooperative agent strategies, enhancing the accuracy and efficiency of ITS applications
such as vehicle and pedestrian tracking [27].
   Vincent et al. (2022) described a MAS using stereovision for perception, enabling agents to collaborate
and enhance scene understanding through graph matching algorithms. This approach addresses
challenges in correspondence identification and non-covisibility, critical for ITS applications such as
multi-vehicle coordination and traffic management [28].
   Mahmoudi et al. (2013) utilized a MAS for object recognition in complex urban areas, leveraging
WorldView-2 satellite imagery and digital surface models. This system improves object recognition
accuracy through knowledge-based reasoning and cooperative agent capabilities, essential for urban
traffic monitoring and smart city applications [29].

2.3. Positioning Our Proposal
In light of the existing work, our proposal aims to integrate the strengths of both bounding box fusion
techniques and MASs to develop a more robust and efficient object detection framework tailored for ITS
applications. Our approach leverages the distributed processing capabilities of MASs to enhance the
accuracy and scalability of bounding box fusion methods. By incorporating advanced fusion techniques
and adaptive agent strategies, our system aims to address the limitations of existing methods, such as
handling dynamic environments and improving detection precision. Our contributions include:
   1. A multi-agent based framework for bounding box improvement that dynamically assigns agents
      to handle specific bounding boxes.
   2. Integration of advanced fusion techniques, such as Weighted Box Fusion (WBF) and Non-
      Maximum Suppression (NMS), to enhance detection accuracy in various ITS scenarios.
   3. Implementation of adaptive agent strategies / behaviors that allow the switch between cooperation
      and competition dynamically, ensuring robust performance in real-world ITS applications.
  To the best of our knowledge, we are among the first to propose integrating MAS into specific
computer vision sub-tasks such as bounding box filtering and fusion. This approach aims to exploit the
advantages of MAS to enhance the accuracy, efficiency, and adaptability of object detection systems in
ITS applications.
3. System Architecture for AWBF
The agentified Weighted Boxes Fusion (WBF) system integrates multiple agents, each handling individual
bounding boxes from various detection models. This Multiagent System (MAS) enhances the efficiency
and accuracy of bounding box fusion through distributed processing and specialized agent roles. A
central blackboard mechanism facilitates information sharing and coordination.
   MAS offers decentralized decision-making and dynamic adaptability, enhancing resilience and flexi-
bility in handling varied scenarios [30].
                                                       Blackboard



                Model 1   Model1 specific
                          agent                                                            Coordinator Agent




                Model 2   Model2 specific
                          agent                                                                       BB Agent 4 (people)


                                                                    BB Agent1 (bus)                             BB Agent 5 (people)
                                                                                          BB Agent 3 (car)
                                                                            BB Agent 2 (bus)
                          Model3 specific
                Model 3
                          agent




                                            DATA Processing Agent
                                                                           BB1
                                                                            BB2                    BB3         BB4     BB5




Figure 1: AWBF Agents, colors correspond to the models who generate initial bounding boxes


   The blackboard acts as a global communication hub, simplifying data interactions and providing a
robust framework for synchronized information exchange among agents [31]. Specific agent roles, from
bounding box processing to model-specific adaptations, optimize performance and accuracy by leverag-
ing domain-specific knowledge and algorithms [32]. Feedback mechanisms enable dynamic adaptation,
allowing agents to adjust strategies based on performance and data input changes, maintaining high
accuracy in dynamic environments [33].

3.1. Overview of Agent Roles
The system includes various agents with specific responsibilities:
    • Bounding-Box Agents: Handle individual bounding boxes, analyze, and propose fusions with
      overlapping boxes.
    • Model-specific Agents: Manage bounding boxes from specific detection models. Can be seen as
      interfaces between the MAS and CV models. Each agent extracts bounding box proposals from
      its respective model to ensure compatibility and apply model-specific behaviors and adjustments.
    • Coordinator Agents: Oversee the fusion process, resolve conflicts between bounding-box agents,
      and make final decisions on merged bounding boxes.
    • Data Processing Agents: Optionally handle image preprocessing and result postprocessing.

3.2. Blackboard Information Sharing System
The blackboard serves as a shared information space for communication and data exchange:
    • Data Repository: Central storage for bounding box data, including coordinates, confidence
      scores, and model origins.
    • Communication Medium: Allows agents to read and write data, maintaining system modularity
      and scalability.
    • Coordination Facilitator: Coordinates actions among agents, especially in resolving fusion
      conflicts.
3.3. Processing Workflow
The workflow involves:
   1. Data Input and Distribution: Model-specific Agents extract bounding boxes from different
      models and transfer them to Data processing agents who prepare and distribute bounding boxes
      to bounding box agents.
   2. Bounding Box Analysis and Posting: Bounding box agents analyze and post findings to the
      blackboard, proposing fusions.
   3. Review and Fusion: Coordinator agents review and finalize fusion decisions, consulting model-
      specific agents as needed.
   4. Final Processing and Output: Data processing agents optimize the fused bounding boxes for
      downstream applications.
   5. Feedback and Adaptation: The system adapts to changes by updating agent strategies or
      parameters based on performance metrics.


4. Implementation and Development of Agent Behaviors
Our implementation is developed in Python, utilizing the existing WBF codebase to maintain consistency
in data processing. By forking the original WBF repository, we leverage developed libraries, utilities,
and functions, ensuring the use of the exact same logic in data processing. This allowed us to focus
on integrating MAS features without reinventing the core bounding box fusion logic. We built an
ad-hoc MAS framework tailored to our requirements. The agents interact via a shared blackboard for
communication, and the system supports both centralized and decentralized processing. Following
the system architecture described in the previous section, one can implement diverse behaviors and a
variety of solution method logics by only changing the decision logic of the bounding box agent and
adjusting the coordination mechanism.
   Model-specific Agents interact with existing object detection models (e.g., YOLO, Faster R-CNN) to
receive and process bounding boxes. Model-specific agents convert detection outputs into a standard
format used by the system.
   Main implementation challenges included managing computation time, communication overhead,
and integrating the MAS with existing computer vision models. Future improvements will focus on
developing variety of agent behaviors with optimized parameters for computational and accuracy per-
formance, enhancing the system’s scalability, robustness, and adaptability, exploring further integration
with advanced machine learning models and real-world deployment scenarios.

4.1. Agent Behaviors
We developed two distinct agent behaviors to demonstrate the versatility and potential of MAS in object
detection. The first behavior replicates the Weighted Boxes Fusion (WBF) in a decentralized manner,
while the second introduces a competitive interaction among agents.

4.1.1. Behavior 1: Decentralized Weighted Boxes Fusion (WBF)
This behavior replicates the state-of-the-art WBF method in a decentralized manner. Each agent
processes bounding boxes independently and posts results to a shared blackboard (see Algorithm 1),
improving system resilience. The agent determines overlapping boxes as candidates for fusion by
calculating the Intersection over Union (IoU). Boxes are considered for fusion if their IoU exceeds a
certain threshold. The IoU calculation is given by:

                                                     𝑎𝑟𝑒𝑎(𝐵𝑜𝑥1 ∩ 𝐵𝑜𝑥2 )
                              𝐼𝑜𝑈 (𝐵𝑜𝑥1 , 𝐵𝑜𝑥2 ) =
                                                     𝑎𝑟𝑒𝑎(𝐵𝑜𝑥1 ∪ 𝐵𝑜𝑥2 )
Algorithm 1 Decentralized WBF Algorithm (AWBF) - BoundingBox Agent behavior
 1: Input: Bounding boxes 𝐵, confidence scores 𝑆, labels 𝐿
 2: Read 𝐵, 𝑆, 𝐿 from the blackboard
 3: Determine overlapping boxes as candidates for fusion
 4: Filter candidates using IoU metric
 5: Apply WBF on the final set of candidates
 6: Post fused boxes to the blackboard
 7: Output: Fused bounding boxes


Algorithm 2 Competitive Interaction Algorithm - BoundingBox Agent 𝐴𝑖 behavior
 1: Input: Bounding boxes 𝐵, confidence scores 𝑆, labels 𝐿
 2: 𝐴𝑖 reads overlapping boxes from the blackboard
 3: for each overlapping box 𝐵𝑖 do
 4:    Calculate 𝐼𝑜𝑈 and 𝐼𝑜𝐵 between 𝐴𝑖 and 𝐵𝑗
 5:    Calculate attack strength 𝑆attack = confidence𝐴𝑖 × 𝐼𝑜𝐵𝐵𝑗
 6:    Calculate defense strength 𝑆defense = confidence𝐵𝑗 × 𝐼𝑜𝐵𝐴𝑖
 7:    Calculate result 𝑅 = 𝑆attack − 𝑆defense
 8:    if 𝑅 > 𝑇 then
 9:        𝐴𝑖 wins and 𝐵𝑗 is removed
10:    else if 𝑅 < −𝑇 then
11:        𝐵𝑗 wins and 𝐴𝑖 is removed
12:    else
13:        Fuse 𝐴𝑖 and 𝐵𝑗 using weighted average
14:    end if
15: end for
16: 𝐴𝑖 posts result to the blackboard
17: Output: Final bounding boxes



4.1.2. Behavior 2: Competitive Interaction
In this behavior, agents compete based on a new metric that we introduce as Intersection over Box
area(IoB). The IoBs for two boxes, 𝐴 and 𝐵, are calculated separately as:

                                    𝑎𝑟𝑒𝑎(𝐴 ∩ 𝐵)                  𝑎𝑟𝑒𝑎(𝐴 ∩ 𝐵)
                        𝐼𝑜𝐵𝐴|𝐵 =                ,    𝐼𝑜𝐵𝐵|𝐴 =
                                      𝑎𝑟𝑒𝑎(𝐴)                      𝑎𝑟𝑒𝑎(𝐵)

Attacking or cooperating with other agents depending on calculated strengths. The strength of an
attack of 𝐴 on 𝐵 and defense of 𝐵 against 𝐴 are defined by:

         𝑆attack (𝐴, 𝐵) = confidence𝐴 × 𝐼𝑜𝐵𝐵|𝐴 ,     𝑆defense (𝐵, 𝐴) = confidence𝐵 × 𝐼𝑜𝐵𝐴|𝐵

The decision rule is based on the difference between attack and defense strengths and a decision
threshold (𝑇 ):            Result(𝐴, 𝐵) = 𝑆attack (𝐴, 𝐵) − 𝑆defense (𝐵, 𝐴)

                                  ⎨Result(𝐴, 𝐵) > 𝑇 :       𝐴 wins and 𝐵 is removed
                                  ⎧
                                  ⎪
              winner determination Result(𝐴, 𝐵) < −𝑇 : 𝐵 wins and 𝐴 is removed
                                     otherwise :            𝐴 and 𝐵 fuse using WBF
                                  ⎪
                                  ⎩

The least case represent the area where agents can cooperate as their strengths are close. Threshold 𝑇
can determine the level of cooperativeness, and thus the value (1 − 𝑇 ) refers to the competitiveness
level. (𝑇 = 1) indicates full cooperativeness settings, reverting to AWBF. Contrarily, (𝑇 = 0) indicates
full competitiveness unless attack and defense strengths are equal.
Illustrative Example: Bounding Box Fusion for Bicycle Detection
To illustrate the AWBF and competitive behavior in action, we consider the detection of bicycles in
image "138639" from COCO dataset using two ad-hoc models. (see Figure 2)




     (a) Model 1 Proposals                  (b) Model 2 Proposals                  (c) Combined Proposals




                      (d) AWBF Result                               (e) Competitive Results
        Figure 2: Visualization of Bounding Box Proposals and Fusion Results on COCO#138639 (images are
        cropped to emphasize the area of interest)


  The bounding boxes from the two models are as follows:

    • Model 1: {‘box’: [0.192, 0.752, 0.312, 0.873], ‘score’: 0.9, ‘label’: 2}
    • Model 2: {‘box’: [0.203, 0.756, 0.314, 0.875], ‘score’: 0.5, ‘label’: 2}

The Intersection over Union for the bounding boxes is: IoU = area of overlap
                                                              area of union ≈ 0.85
If we apply the WBF method:
                        0.9 · [0.192, 0.752, 0.312, 0.873] + 0.5 · [0.203, 0.756, 0.314, 0.875]
            WBFbox =
                                                       0.9 + 0.5
                                                                      0.9 + 0.5
                 WBFbox ≈ [0.196, 0.754, 0.313, 0.874] , WBFscore =             = 0.7
                                                                          2
  For competitive behavior, the attack and defence strengths rely on the calculation of the Intersection
over Box values:
                             area(𝐵1 ∩ 𝐵2)                     area(𝐵1 ∩ 𝐵2)
              IoB𝐵1|𝐵2 =                   ≈ 0.89 , IoB𝐵2|𝐵1 =               ≈ 0.91
                                area(𝐵1)                          area(𝐵2)
               Attack𝐵1|𝐵2 = 0.9 · 0.91 ≈ 0.819 , Defense𝐵2|𝐵1 = 0.5 · 0.89 ≈ 0.445
                             Result = Attack𝐵1|𝐵2 − Defense𝐵2|𝐵1 = 0.374
Given (𝑇 = 0.3), the agent 𝐵1 wins and 𝐵2 is removed as (Result > 𝑇 ). Increasing the 𝑇 value to 4,
the conflict result will fall into the cooperation range and thus we return back to AWBF.


5. Experimental Evaluation
To evaluate our methods, we conducted extensive tests using the COCO dataset. Our primary objective
was to demonstrate the proof of concept without optimizing parameters or model weights beyond the
default settings provided by the WBF code. Therefore, our results focus on comparing performance
metrics rather than optimizing for maximum accuracy.
Evaluation Metrics The evaluation metrics used were those recommended and specified by COCO
dataset. Namely, Average Precision and Average Recall:

- Average Precision (AP) Reveals the model’s ability to make accurate positive predictions. It is
      calculated at different Intersection over Union (IoU) thresholds.
              • AP@[IoU=0.50:0.95]: This is the average AP over ten IoU thresholds (0.50 to 0.95 with a
                step size of 0.05).
              • AP@0.50: This is the AP at an IoU threshold of 0.5.
              • AP@0.75: This is the AP at an IoU threshold of 0.75.
              • AP[small]: AP for small objects (area < 32 pixels).
              • AP[medium]: AP for medium sized objects (32 ≤ area ≤ 96 pixels).
              • AP[large]: AP for large objects ( area ≥ 96 pixels).

- Average Recall (AR) Measuring the sensitivity by focusing on the model’s ability to correctly iden-
      tify positive samples from the entire pool of positive instances.
              • AR@[IoU=0.50:0.95]: This is the average recall over ten IoU thresholds (0.50 to 0.95 with a
                step size of 0.05).
              • AR@0.50: This is the average recall at an IoU threshold of 0.5.
              • AR@0.75: This is the average recall at an IoU threshold of 0.75.
              • AR[small]: AR for small objects.
              • AR[medium]: AR for medium objects.
              • AR[large]: AR for large objects.

  The results from test runs over the entire dataset are shown in the Table 1. Notably, the results
demonstrate that AWBF outperforms individual models whose outputs were used in the fusion process.
Although our results did not surpass those of the centralized WBF, they were mostly comparable.
Specifically, our approach performed better than WBF on AP-small and AR@10 at an IoU of 0.5.

                                          Avg. Precision                                                Avg. Recall
                 @[0.5 , 0.95]   @[0.5]    @[0.75]    Small   Medium   Large   @[0.5 , 0.95]   @[0.5]   @[0.75]   Small   Medium   Large
 EffNetB0           0.336        0.515      0.354     0.125    0.388   0.528      0.288         0.44     0.467    0.193     0.55   0.688
 EffNetB0-m         0.335        0.516      0.351     0.129    0.389   0.524      0.288        0.441     0.467    0.198     0.55   0.687
 EffNetB1           0.392        0.581      0.418     0.186    0.447   0.571      0.322        0.501     0.532    0.294    0.599   0.735
 EffNetB1-m         0.392        0.581      0.417     0.184    0.447   0.571      0.323        0.502     0.531    0.279    0.602   0.735
 EffNetB2           0.425        0.617      0.453     0.238    0.479   0.591       0.34        0.537     0.569    0.347    0.632    0.75
 EffNetB2-m         0.426        0.617      0.454      0.24    0.481   0.593      0.341        0.537     0.569    0.358    0.634   0.748
 EffNetB3           0.459         0.65      0.491      0.28    0.503   0.616      0.359        0.569     0.604    0.404    0.654    0.77
 EffNetB3-m         0.455        0.646      0.487     0.282    0.494   0.618      0.357        0.566      0.6     0.412     0.65   0.766
 EffNetB4            0.49        0.685      0.529     0.334    0.538    0.64      0.375        0.598     0.634    0.464    0.682   0.782
 EffNetB4-m         0.488        0.684      0.524      0.33    0.533   0.642      0.373        0.596     0.633    0.468     0.68   0.783
 EffNetB5           0.505         0.7       0.544     0.343    0.549   0.646      0.383        0.619     0.656     0.5     0.698   0.791
 EffNetB5-m         0.502        0.696      0.539     0.335    0.546   0.645      0.379        0.614     0.651    0.484    0.692   0.789
 EffNetB6           0.513        0.705      0.555     0.352    0.556   0.652      0.387        0.626     0.664    0.505    0.703   0.795
 EffNetB6-m         0.511        0.701      0.551     0.341    0.555   0.654      0.384        0.623      0.66    0.489    0.704   0.805
 EffNetB7           0.521         0.71      0.562      0.37    0.562    0.66       0.39        0.633     0.671    0.517    0.711   0.801
 EffNetB7-m         0.519         0.71      0.558     0.364    0.562   0.659      0.388         0.63     0.668    0.509     0.71   0.803
 DetRS              0.515         0.71      0.654     0.318    0.565   0.676      0.384        0.628     0.671    0.479    0.723   0.828
 DetRS-m            0.515        0.707      0.564     0.316    0.563   0.677      0.384        0.629     0.673    0.486    0.721   0.834
 resnet50           0.496        0.697      0.538     0.299    0.543   0.656      0.378        0.607      0.64    0.457    0.686     0.8
 resnet50-m         0.496        0.694      0.535     0.296    0.545   0.657      0.379         0.61     0.642    0.464    0.689   0.799
 yolo                 0.5        0.678      0.546     0.336    0.544   0.644      0.381        0.628     0.688    0.533    0.734   0.826
 WBF                0.673        0.894      0.709     0.605    0.731   0.846      0.471        0.627     0.846     0.8     0.85    0.867
 AWBF                0.61         0.66      0.625      0.61    0.766   0.675      0.395        0.676     0.745    0.664    0.706   0.819

Table 1
Benchmarking on COCO dataset
5.1. WBF Performance on Different Dataset Sizes:
Wen running experiments on subsets of the COCO dataset with different sizes, we observed that the
centralized WBF method performs better with larger datasets but shows reduced efficiency on smaller
datasets (see Figure 3). This can be explained by several factors:

    • Law of Large Numbers: As the dataset size increases, the averaging process tends to smooth
      out random errors and fluctuations, leading to improved performance for the centralized WBF
      method.
    • Error Compensation: With more data points, errors in individual detections can compensate
      for each other, leading to more accurate fusion results.
    • Increased Data Redundancy: Larger datasets contain more redundant information, reinforcing
      correct detections and diluting the impact of incorrect ones.

                         AVG PRECISION @ IOU [ 0.5 , 0,95]                                          AVG PRECISION @ IOU = 0.5                                          AVG PRECISION @ IOU = 0.75
                                   ALL AREA SIZES                                                         ALL AREA SIZES                                                      ALL AREA SIZES
            1                                                                        1                                                                    1

           0,8                                                                     0,8                                                                   0,8

           0,6                                                                     0,6                                                                   0,6

           0,4                                                                     0,4                                                                   0,4

           0,2                                                                     0,2                                                                   0,2

            0                                                                        0                                                                    0
                 0            100         200       300         400    500   600           0         100      200      300         400     500    600          0         100     200       300        400   500   600
                                                  NB EXAMPLES                                                        NB EXAMPLES                                                        NB EXAMPLES



                         AVG PRECISION @ IOU [ 0.5 , 0,95]                                     AVG PRECISION @ IOU [ 0.5 , 0,95]                                   AVG PRECISION @ IOU [ 0.5 , 0,95]
                                    SMALL BOXES                                                      MEDIUM AREA BOXES                                                        LARGE BOXES
             1                                                                            1                                                                    1
           0,8                                                                           0,8                                                               0,8

           0,6                                                                           0,6                                                               0,6

           0,4                                                                           0,4                                                               0,4

           0,2                                                                           0,2                                                               0,2

             0                                                                            0                                                                    0
                 0            100         200       300         400    500   600               0       100     200      300         400    500    600              0      100     200      300        400   500   600
                                                  NB EXAMPLES                                                        NB EXAMPLES                                                        NB EXAMPLES



                             AVG RECALL @ IOU [ 0.5 , 0,95]                                           AVG RECALL @ IOU = 0.5                                              AVG RECALL @ IOU =0,75
                                    ALL AREA SIZES                                                         ALL AREA SIZES                                                      ALL AREA SIZES
             1                                                                      1                                                                          1

           0,8                                                                     0,8                                                                     0,8

           0,6                                                                     0,6                                                                     0,6

           0,4                                                                     0,4                                                                     0,4

           0,2                                                                     0,2                                                                     0,2

             0                                                                      0                                                                          0
                 0            100         200      300          400    500   600          0          100      200      300         400     500    600              0      100     200      300        400   500   600
                                                                                                                     NB EXAMPLES                                                        NB EXAMPLES



                             AVG RECALL @ IOU [ 0.5 , 0,95]                                        AVG RECALL @ IOU [ 0.5 , 0,95]                                      AVG RECALL @ IOU [ 0.5 , 0,95]
                                     SMALL BOXES                                                        MEDIUM AREA BOXES                                                      LARGE BOXES
                                                                                           1                                                                   1
                     1
                 0,8                                                                     0,8                                                               0,8

                 0,6                                                                     0,6                                                               0,6

                 0,4                                                                     0,4                                                               0,4

                 0,2                                                                     0,2                                                               0,2

                     0                                                                     0                                                                   0
                         0          100     200      300         400   500   600               0       100     200       300        400     500    600             0       100    200       300       400   500   600
                                                  NB EXAMPLES                                                        NB EXAMPLES                                                        NB EXAMPLES




                                                                                                             AWBF                         WBF
Figure 3: COCO evaluation metrics evolution as function of the size of test set - Evaluating the AWBF method
performance on subsets of COCO dataset



5.2. AWBF Performance on Different Dataset Sizes:
The AWBF method exhibited more robust and stable performance across varying dataset sizes as
Figure 3 shows, which can be attributed to the distributed processing and the redundancy: Each agent
processes bounding boxes independently and in parallel, reducing the impact of individual errors
and improving overall robustness. Also, Each agent’s localized decision-making can lead to better
performance, especially in smaller datasets where individual detections have a higher impact.
5.3. Competitive Behavior Experiments:
We also evaluated the competitive behavior using the default parameters. While the initial results did
not match the quality of WBF, they demonstrated the potential for diverse agent behaviors. By adjusting
the value of T, which controls the level of cooperativeness (1 - competitiveness). We conducted multiple
tests on a subset of 500 COCO images, varying the competitiveness level. We observed an interesting
trend, as the results showed that increasing competitiveness improved precision (see Figure 4).




Figure 4: Precision and recall values evolution with the increase of competition level (decrease in cooperation
threshold T) in the agent behavior
   AP increased with higher competitiveness, likely because competition removed lower-scoring boxes,
reducing false positives and improving precision. Recall remained stable as even with fewer boxes,
sufficient accurate boxes were retained.
   To summarize, theses evaluations demonstrated the flexibility and potential of integrating MAS into
object detection workflows. While the competitive agent behavior requires further optimization, the
initial results validate our approach and open avenues for more sophisticated multi-agent behaviors in
future work.


6. Conclusion
In this work, we presented a proof-of-concept implementation integrating MAS into object detection
workflows, specifically focusing on improving bounding box predictions, an essential component of
autonomous vehicle perception systems. By leveraging the decentralized processing capabilities of MAS,
we demonstrated two distinct agent behaviors: Decentralized (Agentified) Weighted Boxes Fusion and
Competitive Interaction. Our experimental evaluation using the COCO dataset showed that while the
decentralized WBF approach performed comparably to the centralized WBF, the competitive behavior
illustrated the potential for further optimization and innovation in agent-based object detection systems.
The results indicate that MAS can offer robust and adaptable solutions for object detection tasks, partic-
ularly in dynamic and complex environments like AV perception and intelligent transportation systems.
Future work will focus on refining agent behaviors, enhancing system scalability, and integrating more
advanced machine learning models to further improve performance and adaptability for AV applications.


Acknowledgments
This work is funded by the French National Research Agency as part of the MultiTrans project under
reference ANR-21-CE23-0032.
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