RAWIC: Bit-Depth Adaptive Lossless Raw Image Compression

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Zheng, Chunhang, Xu, Tongda, Xie, Mingli, Wang, Yan, Li, Dou
Format: Preprint
Publié: 2026
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866911553150779392
author Zheng, Chunhang
Xu, Tongda
Xie, Mingli
Wang, Yan
Li, Dou
author_facet Zheng, Chunhang
Xu, Tongda
Xie, Mingli
Wang, Yan
Li, Dou
contents Raw images preserve linear sensor measurements and high bit-depth information crucial for advanced vision tasks and photography applications, yet their storage remains challenging due to large file sizes, varying bit depths, and sensor-dependent characteristics. Existing learned lossless compression methods mainly target 8-bit sRGB images, while raw reconstruction approaches are inherently lossy and rely on camera-specific assumptions. To address these challenges, we introduce RAWIC, a bit-depth-adaptive learned lossless compression framework for Bayer-pattern raw images. We first convert single-channel Bayer data into a four-channel RGGB format and partition it into patches. For each patch, we compute its bit depth and use it as auxiliary input to guide compression. A bit-depth-adaptive entropy model is then designed to estimate patch distributions conditioned on their bit depths. This architecture enables a single model to handle raw images from diverse cameras and bit depths. Experiments show that RAWIC consistently surpasses traditional lossless codecs, achieving an average 7.7% bitrate reduction over JPEG-XL. Our code is available at https://github.com/chunbaobao/RAWIC.
format Preprint
id arxiv_https___arxiv_org_abs_2603_28105
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle RAWIC: Bit-Depth Adaptive Lossless Raw Image Compression
Zheng, Chunhang
Xu, Tongda
Xie, Mingli
Wang, Yan
Li, Dou
Computer Vision and Pattern Recognition
Raw images preserve linear sensor measurements and high bit-depth information crucial for advanced vision tasks and photography applications, yet their storage remains challenging due to large file sizes, varying bit depths, and sensor-dependent characteristics. Existing learned lossless compression methods mainly target 8-bit sRGB images, while raw reconstruction approaches are inherently lossy and rely on camera-specific assumptions. To address these challenges, we introduce RAWIC, a bit-depth-adaptive learned lossless compression framework for Bayer-pattern raw images. We first convert single-channel Bayer data into a four-channel RGGB format and partition it into patches. For each patch, we compute its bit depth and use it as auxiliary input to guide compression. A bit-depth-adaptive entropy model is then designed to estimate patch distributions conditioned on their bit depths. This architecture enables a single model to handle raw images from diverse cameras and bit depths. Experiments show that RAWIC consistently surpasses traditional lossless codecs, achieving an average 7.7% bitrate reduction over JPEG-XL. Our code is available at https://github.com/chunbaobao/RAWIC.
title RAWIC: Bit-Depth Adaptive Lossless Raw Image Compression
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2603.28105