Patching in Order: Efficient On-Device Model Fine-Tuning for Multi-DNN Vision Applications

The increasing deployment of multiple deep neural networks (DNNs) on edge devices is revolutionizing mobile vision applications, spanning autonomous vehicles, augmented reality, and video surveillance. These applications demand adaptation to contextual and environmental drifts, typically through fine-tuning on edge devices without cloud access, due to increasing data privacy concerns and the urgency for timely responses. However, fine-tuning multiple DNNs on edge devices faces significant challenges due to the substantial computational workload. In this paper, we present PatchLine, a novel framework tailored for efficient on-device training in the form of fine-tuning for multi-DNN vision applications. At the core of PatchLine is an innovative lightweight adapter design called patches coupled with a strategic patch updating approach across models. Specifically, PatchLine adopts drift-adaptive incremental patching, correlation-aware warm patching, and entropy-based sample selection, to holistically reduce the number of trainable parameters, training epochs, and training samples. Experiments on four datasets, three vision tasks, four backbones, and two platforms demonstrate that PatchLine reduces the total computational cost by an average of 55% without sacrificing accuracy compared to the state-of-the-art.