Lightweight Change Detection in Heterogeneous Remote Sensing Images with Online All-Integer Pruning Training

TL;DR

This paper introduces a lightweight change detection method for heterogeneous remote sensing images that uses online all-integer pruning training to reduce computation and memory costs, enabling efficient edge-device deployment.

Contribution

It proposes a novel OAIP training strategy that quantizes all network data to integers and employs adaptive filter pruning, improving efficiency without sacrificing detection accuracy.

Findings

Achieves similar detection performance to state-of-the-art methods

Significantly reduces computation complexity

Lowers memory usage during training

Abstract

Detection of changes in heterogeneous remote sensing images is vital, especially in response to emergencies like earthquakes and floods. Current homogenous transformation-based change detection (CD) methods often suffer from high computation and memory costs, which are not friendly to edge-computation devices like onboard CD devices at satellites. To address this issue, this paper proposes a new lightweight CD method for heterogeneous remote sensing images that employs the online all-integer pruning (OAIP) training strategy to efficiently fine-tune the CD network using the current test data. The proposed CD network consists of two visual geometry group (VGG) subnetworks as the backbone architecture. In the OAIP-based training process, all the weights, gradients, and intermediate data are quantized to integers to speed up training and reduce memory usage, where the per-layer block exponentiation scaling scheme is utilized to reduce the computation errors of network parameters caused by quantization. Second, an adaptive filter-level pruning method based on the L1-norm criterion is employed to further lighten the fine-tuning process of the CD network. Experimental results show that the proposed OAIP-based method attains similar detection performance (but with significantly reduced computation complexity and memory usage) in comparison with state-of-the-art CD methods.