R2C-GAN: Restore-to-Classify Generative Adversarial Networks for blind X-ray restoration and COVID-19 classification

Restoration of poor-quality medical images with a blended set of artifacts plays a vital role in a reliable diagnosis. As a pioneer study in blind X-ray restoration, we propose a joint model for generic image restoration and classification: Restore-to-Classify Generative Adversarial Networks (R2C-GANs). This is the first generic restoration approach forming an Image-to-Image translation task from poor-quality having noisy, blurry, or over/under-exposed images to high-quality image domain where forward and inverse transformations are learned using unpaired training samples. Simultaneously, the joint classification preserves the diagnostic-related label during restoration. Each R2C-GAN is equipped with operational layers/neurons in a compact architecture. The proposed joint model successfully restores images while achieving state-of-the-art Coronavirus Disease 2019 (COVID-19) classification with above 90% in F₁-Score. In qualitative analysis, the restoration performance is confirmed by medical doctors where 68% of the restored images are selected against the original images. We share the software implementation at https://github.com/meteahishali/R2C-GAN.