Towards Distortion-Debiased Blind Image Quality Assessment

Existing blind image quality assessment (BIQA) models are susceptible to biases related to distortion intensity and domain. Intensity bias refers to the relatively accurate perception of severe distortions but larger estimation errors for mild distortions, while domain bias stems from the discrepancies between synthetic and authentic distortion properties. This work introduces a unified learning framework towards addressing these distortion biases. We integrate distortion perception and restoration methods to mitigate intensity bias, where images with minor distortions, which are easily restorable, serve as references for mildly distorted images, while severe distortions benefit directly from distortion perception. The restoration modules employ a combined image-level and feature-level denoising approach, and then an intensity-aware cross-attention mechanism is designed for adaptive handling of intensity bias. To tackle domain bias, we introduce a distortion domain recognition task based on the intrinsic differences between distortion domains and use intra-domain similarity for weighting the quality scores from these domains. Experimental results show that the proposed method achieves state-of-the-art performance on multiple synthetic and authentic distortion datasets. Code and models will be available at https://github.com/xxVENTAZEDxx/Distortion-Debiased-BIQA