Task-Adaptive FFN Editing for Continual Blind Image Quality Assessment

Abstract

Blind Image Quality Assessment (BIQA) models trained on one distortion distribution often degrade when exposed to new ones, making sequential adaptation without forgetting a fundamental challenge. While continual learning offers a natural solution, existing methods typically retrain the entire backbone per task, limiting scalability and parameter efficiency. We propose ContEditIQA, a parameter-efficient framework for continual BIQA that selectively edits a pre-trained Vision Transformer (ViT) rather than retraining it. Following a locate-then-edit strategy, a lightweight attention-guided hypernetwork identifies distortion-sensitive Feed-Forward Network (FFN) parameters for each incoming task and restricts updates to those regions, while attention layers remain frozen to preserve globally shared representations. This targeted editing enables robust sequential adaptation without model expansion or memory replay. Experiments across six BIQA benchmarks demonstrate superior knowledge retention and cross-dataset generalization while modifying fewer than 30% of backbone parameters, establishing selective model editing as an effective and scalable paradigm for continual BIQA.