Zero-Shot Structure-Preserving Diffusion Model for High Dynamic Range Tone Mapping

Tone mapping techniques, aiming to convert high dynamic range (HDR) images to high-quality low dynamic range (LDR) images for display, play a more crucial role in real-world vision systems with the increasing application of HDR images. However, obtaining paired HDR and high-quality LDR images is difficult, posing a challenge to deep learning based tone mapping methods. To overcome this challenge, we propose a novel zero-shot tone mapping framework that utilizes shared structure knowledge, allowing us to transfer a pre-trained mapping model from the LDR domain to HDR fields without paired training data. Our approach involves decomposing both the LDR and HDR images into two components: structural information and tonal information. To preserve the original image's structure, we modify the reverse sampling process of a diffusion model and explicitly incorporate the structure information into the intermediate results. Additionally, for improved image details, we introduce a dual-control network architecture that enables different types of conditional inputs to control different scales of the output. Experimental results demonstrate the effectiveness of our approach, surpassing previous state-of-the-art methods both qualitatively and quantitatively. Moreover, our model exhibits versatility and can be applied to other low-level vision tasks without retraining. The code is available at https://github.com/ZSDM-HDR/Zero-Shot-Diffusion-HDR.