An Efficient Person Clustering Algorithm for Open Checkout-free Groceries

TL;DR

This paper introduces an efficient person clustering algorithm tailored for open checkout-free grocery stores, utilizing a novel Crowded Sub-Graph construction and GCN-based clustering to handle dynamic, massive data streams effectively.

Contribution

The paper presents a new clustering method combining Crowded Sub-Graph and GCN with a Nearest Neighbor strategy, optimized for real-time, dynamic environments in checkout-free grocery systems.

Findings

Outperforms existing algorithms in clustering accuracy and efficiency

Successfully deployed in real-world grocery stores

Handles dynamic and massive data streams effectively

Abstract

Open checkout-free grocery is the grocery store where the customers never have to wait in line to check out. Developing a system like this is not trivial since it faces challenges of recognizing the dynamic and massive flow of people. In particular, a clustering method that can efficiently assign each snapshot to the corresponding customer is essential for the system. In order to address the unique challenges in the open checkout-free grocery, we propose an efficient and effective person clustering method. Specifically, we first propose a Crowded Sub-Graph (CSG) to localize the relationship among massive and continuous data streams. CSG is constructed by the proposed Pick-Link-Weight (PLW) strategy, which \textbf{picks} the nodes based on time-space information, \textbf{links} the nodes via trajectory information, and \textbf{weighs} the links by the proposed von Mises-Fisher (vMF) similarity metric. Then, to ensure that the method adapts to the dynamic and unseen person flow, we propose Graph Convolutional Network (GCN) with a simple Nearest Neighbor (NN) strategy to accurately cluster the instances of CSG. GCN is adopted to project the features into low-dimensional separable space, and NN is able to quickly produce a result in this space upon dynamic person flow. The experimental results show that the proposed method outperforms other alternative algorithms in this scenario. In practice, the whole system has been implemented and deployed in several real-world open checkout-free groceries.