Direct Coloring for Self-Supervised Enhanced Feature Decoupling
Salman Mohamadi, Gianfranco Doretto, Donald A. Adjeroh
TL;DR
This work addresses dimensional collapse in self-supervised learning by introducing direct coloring to actively shape feature correlations, complementing whitening. The method uses a Bayesian-inspired target cross-correlation matrix $E$, derived from variational autoencoders trained on augmented views, and optimizes $\,\mathcal{L} = \mathcal{L}_{W} + \lambda \mathcal{L}_{C}$ to align the coloring cross-correlations with $E$ while whitening decorrelates subsequent embeddings. Theoretical MAP analysis links the objective to Bayesian estimation with a Gaussian prior, and empirically the approach yields faster convergence and improved accuracy across ImageNet, CIFAR-10/100, Tiny ImageNet, and transfer tasks like VOC0712 and COCO, with ablations clarifying the impact of coloring head placement, projector size, and choice of target $E$. The results demonstrate that direct coloring is a practical, broadly applicable enhancement to SSL, reducing the risk of complete collapse and enabling stronger, more transferable representations.
Abstract
The success of self-supervised learning (SSL) has been the focus of multiple recent theoretical and empirical studies, including the role of data augmentation (in feature decoupling) as well as complete and dimensional representation collapse. While complete collapse is well-studied and addressed, dimensional collapse has only gain attention and addressed in recent years mostly using variants of redundancy reduction (aka whitening) techniques. In this paper, we further explore a complementary approach to whitening via feature decoupling for improved representation learning while avoiding representation collapse. In particular, we perform feature decoupling by early promotion of useful features via careful feature coloring. The coloring technique is developed based on a Bayesian prior of the augmented data, which is inherently encoded for feature decoupling. We show that our proposed framework is complementary to the state-of-the-art techniques, while outperforming both contrastive and recent non-contrastive methods. We also study the different effects of coloring approach to formulate it as a general complementary technique along with other baselines.
