Heavy Labels Out! Dataset Distillation with Label Space Lightening
Ruonan Yu, Songhua Liu, Zigeng Chen, Jingwen Ye, Xinchao Wang
TL;DR
This work tackles the heavy-label bottleneck in large-scale dataset distillation by proposing HeLlO, a label-lightening framework that replaces stored soft labels with an online, CLIP-informed image-to-label projector. It introduces a LoRA-like low-rank knowledge transfer and a text-guided initialization to efficiently adapt a foundation-model–based projector to target datasets, while an image-level update tightens the alignment between original and distilled label spaces. Synthetic data are initialized from representative image patches and subsequently updated to minimize information loss, enabling high-quality label generation without large storage overhead. Empirically, HeLlO matches or surpasses state-of-the-art large-scale distillation methods on ImageNet-100/1K using only about $0.003\%$ of the original label storage, and demonstrates strong cross-architecture generalization and continual-learning performance.
Abstract
Dataset distillation or condensation aims to condense a large-scale training dataset into a much smaller synthetic one such that the training performance of distilled and original sets on neural networks are similar. Although the number of training samples can be reduced substantially, current state-of-the-art methods heavily rely on enormous soft labels to achieve satisfactory performance. As a result, the required storage can be comparable even to original datasets, especially for large-scale ones. To solve this problem, instead of storing these heavy labels, we propose a novel label-lightening framework termed HeLlO aiming at effective image-to-label projectors, with which synthetic labels can be directly generated online from synthetic images. Specifically, to construct such projectors, we leverage prior knowledge in open-source foundation models, e.g., CLIP, and introduce a LoRA-like fine-tuning strategy to mitigate the gap between pre-trained and target distributions, so that original models for soft-label generation can be distilled into a group of low-rank matrices. Moreover, an effective image optimization method is proposed to further mitigate the potential error between the original and distilled label generators. Extensive experiments demonstrate that with only about 0.003% of the original storage required for a complete set of soft labels, we achieve comparable performance to current state-of-the-art dataset distillation methods on large-scale datasets. Our code will be available.
