Title: Differentiable JPEG-based Input Perturbation for Knowledge Distillation Amplification via Conditional Mutual Information Maximization
Primary area: unsupervised, self-supervised, semi-supervised, and supervised representation learning
Keywords: Knowledge Distillation, JPEG, Conditional Mutual Information

Abstract: Maximizing conditional mutual information (CMI) has recently been shown to enhance the effectiveness of teacher networks in knowledge distillation (KD). Prior work achieves this by fine-tuning a pretrained teacher to maximize a proxy of its CMI. However, fine-tuning large-scale teachers is often impractical, and proxy-based optimization introduces inaccuracies.
 To overcome these limitations, we propose Differentiable JPEG-based Input Perturbation (DJIP), a plug-and-play framework that improves teacher–student knowledge transfer without modifying the teacher. DJIP employs a trainable differentiable JPEG layer inserted before the teacher to perturb teacher inputs in a way that directly increases CMI. We further introduce a novel alternating optimization algorithm to efficiently learn the coding parameters of the JPEG layer to maximize the perturbed CMI. Extensive experiments on CIFAR-100 and ImageNet, across diverse distillers and architectures, demonstrate that DJIP consistently improves student accuracy-achieving up to 4.11% gains-while remaining computationally lightweight and fully compatible with standard KD pipelines.