EquivFlow：VAE 感知的 HDR 编码方法用于 SDR 转 HDR 视频重建
Dark Matters: VAE-Aware HDR Encoding for SDR-to-HDR Video Reconstruction
AI 导读
研究者提出 EquivFlow，一种可逆的曝光等变 HDR 编码方法，用于 SDR 转 HDR 视频重建，无需修改预训练 VAE。常见的 log 类编码会在生成前抑制低亮度色彩差异，导致冻结 VAE 潜空间出现"暗侧塌缩"。在多个预训练图像与视频 VAE 上的编码级测试显示其曝光结构与深暗区色彩传递保持稳定，集成到 SDR-to-HDR 视频扩散模型后带来一致色彩保真度提升。
正文 · 原文
Abstract:SDR-to-HDR reconstruction is an ill-posed problem in which clipped highlights, crushed shadows, and quantization artifacts must be recovered while preserving the original content. Latent diffusion models provide powerful generative priors for restoring missing detail, but their effectiveness is constrained by how HDR signals pass through the pretrained VAE. We find that common log-like encodings suppress low-luminance chromatic differences before generation, producing a dark-side collapse in the frozen-VAE latent. We introduce EquivFlow, a compact, invertible exposure-equivariant encoding that maps exposure changes to additive shifts while retaining a scale-independent chromatic component, without modifying the VAE. Encoding-level tests across pretrained image and video VAEs show that its exposure structure and deep-dark chroma transport persist across the tested hosts. Integrated into SDR-to-HDR video diffusion, EquivFlow delivers consistent chromatic-fidelity gains across the tested settings while retaining competitive reconstruction fidelity.
| Comments: | 13 pages, 4 figures |
| Subjects: | Computer Vision and Pattern Recognition (cs.CV); Artificial Intelligence (cs.AI) |
| Cite as: | arXiv:2611.13504 [cs.CV] |
| (or arXiv:2611.13504v1 [cs.CV] for this version) | |
| https://doi.org/10.48550/arXiv.2611.13504 arXiv-issued DOI via DataCite (pending registration) |
Submission history
From: Donghoon Cha [view email]
[v1]
Tue, 10 Nov 2026 03:16:31 UTC (2,728 KB)
来源：arXiv cs.AI · arxiv.org