Multi-Camera Trajectory Generation with Hierarchical Tracklet Clustering

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Solution Overview

Problem

Existing multi-camera tracking systems struggle to accurately generate trajectory information due to issues with intra-camera and inter-camera tracking, leading to incomplete and inaccurate integration of tracklets, especially when information is lacking.

Innovation Solution

A non-transitory computer-readable recording medium containing a trajectory generation program that performs preprocessing, global optimization processing, including ID transfer error removal, optimized hierarchical clustering, pose-oriented grouping, and error suppression to integrate and refine tracklets, ensuring accurate trajectory generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multi-camera tracking system uses conventional intra-camera and inter-camera tracking methods, then tracking process can be completed, but trajectory information generation accuracy deteriorates due to incomplete and inaccurate integration of tracklets

Engineering Contradiction:
Improvetrajectory information generation accuracyVSAvoidtracklet integration accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent segments the tracklet integration process into multiple hierarchical levels: first clustering tracklets into representative clusters based on appearance features, then further clustering into subclusters based on pose information. This multi-level segmentation allows systematic integration of tracklets while maintaining accuracy by addressing different aspects of similarity at different levels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds another dimension to the clustering process by introducing pose-based clustering as a second level after appearance-based clustering. This dimensional extension from single-criterion to multi-criteria clustering enables more accurate discrimination between different persons and improves trajectory information generation accuracy.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If conventional tracking methods are used, then processing can be performed, but tracking accuracy deteriorates due to inability to accurately distinguish between different persons

Engineering Contradiction:
Improvetracking accuracyVSAvoidperson identification accuracy
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the clustering process into two distinct stages: first clustering based on appearance features to form representative clusters, then clustering based on pose features to form subclusters. This segmentation prevents mixing of different persons by addressing appearance similarity and pose characteristics separately, thereby maintaining person identification accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies different clustering criteria to different levels of the hierarchy: appearance-based clustering at the first level and pose-based clustering at the second level. This local differentiation of clustering quality allows precise distinction between persons with similar appearances but different poses, improving tracking accuracy.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If simple clustering is used, then processing is simple, but trajectory integration becomes inaccurate when information is lacking

Engineering Contradiction:
Improveprocessing simplicityVSAvoidtrajectory integration accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent segments the clustering process into two hierarchical levels with different criteria. The first level uses appearance features for broad grouping, while the second level uses pose features for precise differentiation. This segmented approach maintains processing manageability while significantly improving integration accuracy, especially when information is incomplete.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary appearance-based clustering before pose-based clustering. This preliminary action organizes tracklets into representative clusters based on dominant appearance features, providing a structured foundation that simplifies subsequent pose-based differentiation and improves overall integration accuracy.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS20260004436A1Non-transitory computer readable recording medium, trajectory generation method, and information processing apparatus
Publication Date: 2026.01.01 FUJITSU LTD
  • US20260004436A1 patent drawing
  • US20260004436A1 patent drawing
  • US20260004436A1 patent drawing

AI summary

A non-transitory computer-readable recording medium has stored therein a trajectory generation program that causes a computer to execute a process including generating a fragmentary trajectory of the person based on the acquired analysis result calculating a feature amount based on a plurality of image frames associated with the generated fragmentary trajectory generating a plurality of representative clusters by clustering a plurality of specified fragmentary trajectories using a similarity of representative values of the calculated feature amounts of the plurality of image frames generating a plurality of subclusters obtained by clustering each of the plurality of clustered trajectories in each of the generated representative clusters using representative values of a plurality of poses of the person and setting the plurality of trajectories corresponding to the subcluster as a fragmentary trajectory of the same person based on a result of the plurality of generated subclusters.