titleProjection Pursuit CPCANet for Domain Generalization
authorsYu-Hsi Chen, Abd-Krim Seghouane
date2026-07-24
venuearXiv (preprint, not peer reviewed)
idarXiv:2607.22117
affiliationThe University of Melbourne
linksabs pdf hf code
abstractDomain Generalization (DG) aims to learn representations robust to distribution shifts. Recent geometric alignment methods, such as CPCANet, extract domain-invariant structures through batch-wise Common Principal Component Analysis (CPCA). However, CPCANet suffers from rank-deficient covariance estimation due to the small-sample-size issue in mini-batch training. To address this limitation, we propose Projection Pursuit CPCANet (PP-CPCANet), a covariance-free framework that learns a global orthogonal basis on the Stiefel manifold and jointly optimizes it with network parameters via the Cayley transform. We further introduce a symmetry-breaking detached-median PP dispersion objective to extract common principal components (CPCs) with dense and robust optimization signals. Experiments on four DG benchmarks show that PP-CPCANet achieves SOTA performance while maintaining stable training.

cite

@misc{chen2026projection,
  title={Projection Pursuit CPCANet for Domain Generalization},
  author={Yu-Hsi Chen and Abd-Krim Seghouane},
  year={2026},
  eprint={2607.22117},
  archivePrefix={arXiv},
  url={https://arxiv.org/abs/2607.22117}
}