Recently, research on denoising diffusion models has expanded its application to the field of image restoration. Traditional diffusion-based image restoration methods utilize degraded images as conditional input to effectively guide the reverse generation process, without modifying the original denoising diffusion process. However, since the degraded images already include low-frequency information, starting from Gaussian white noise will result in increased sampling steps. We propose Resfusion, a general framework that incorporates the residual term into the diffusion forward process, starting the reverse process directly from the noisy degraded images. The form of our inference process is consistent with the DDPM. We introduced a weighted residual noise, named resnoise, as the prediction target and explicitly provide the quantitative relationship between the residual term and the noise term in resnoise. By leveraging a smooth equivalence transformation, Resfusion determine the optimal acceleration step and maintains the integrity of existing noise schedules, unifying the training and inference processes. The experimental results demonstrate that Resfusion exhibits competitive performance on ISTD dataset, LOL dataset and Raindrop dataset with only five sampling steps. Furthermore, Resfusion can be easily applied to image generation and emerges with strong versatility.

Recently, research on denoising diffusion models has expanded its application to the field of image restoration. Traditional diffusion-based image restoration methods utilize degraded images as conditional input to effectively guide the reverse generation process, without modifying the original denoising diffusion process. However, since the degraded images already include low-frequency information, starting from Gaussian white noise will result in increased sampling steps. We propose Resfusion, a general framework that incorporates the residual term into the diffusion forward process, starting the reverse process directly from the noisy degraded images. The form of our inference process is consistent with the DDPM.

Recently, Denoising Diffusion Probabilistic Models have been widely used in image segmentation, by generating segmentation masks conditioned on the input image. However, previous works can not seamlessly integrate existing end-to-end models with denoising diffusion models. Existing research can only select acceleration steps based on experience rather than calculating them specifically. Moreover, most methods are limited to small models and small-scale datasets, unable to generalize to general datasets and a wider range of tasks. Therefore, we propose Resfusion with a novel resnoise-diffusion process, which gradually generates segmentation masks or any type of target image, seamlessly integrating state-of-the-art end-to-end models and denoising diffusion models. Resfusion bridges the discrepancy between the likelihood output and the ground truth output through a Markov process. Through the novel smooth equivalence transformation in resnoise-diffusion process, we determine the optimal acceleration step. Experimental results demonstrate that Resfusion combines the capabilities of existing end-to-end models and denoising diffusion models, further enhancing performance and achieving outstanding results. Moreover, Resfusion is not limited to segmentation tasks, it can easily generalize to any general tasks of image generation and exhibit strong competitiveness.