Abstract
Color enhancement of 4K images must meet a quality target under a tight compute budget. Three-dimensional lookup tables (3D LUTs) dominate real-time enhancement because they decide at low resolution and apply a per-pixel lookup at full resolution. A single global LUT, however, is spatially invariant, so an underexposed shadow and a well-exposed region that share a pixel value receive identical corrections. Spatially heterogeneous demands cannot be expressed by such a mapping. We propose LoopLUT, a region-cascaded 3D LUT with progressive refinement. A global LUT performs the overall correction, followed by K-1 loop iterations. In each iteration a gating head predicts at low resolution the region that still needs correction, then builds a residual LUT from the color statistics of that region alone. The cascaded gates form a partition of unity, so the output is a per-pixel convex combination of the K lookup results. Fusion is therefore performed by the gates themselves, with no separate fusion module and no interpolation error accumulating across rounds. The decision stage runs at a fixed 256x256 resolution, independent of output resolution, so a 4K image costs only K pure lookups. Extensive experiments across four benchmarks show that LoopLUT improves PSNR by up to 2.81 dB over the strongest prior method, while keeping real-time throughput at 4K. The same decomposition also generalizes well to underwater enhancement datasets.
Keywords
Publication details
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Cite this article
APA 7
Ye, Y., Ma, J., Wu, C., Wang, W., Lu, D., Zhang, G., Fan, L., & Zheng, Z. (2026). LoopLUT: 3D Lookup Tables with Progressive Region Refinement for Real-Time 4K Image Enhancement. https://omanscience.com/en/articles/looplut-3d-lookup-tables-with-progressive-region-refinement-for-real-time-4k-image-enhancement
MLA 9
Ye, Yang, et al. "LoopLUT: 3D Lookup Tables with Progressive Region Refinement for Real-Time 4K Image Enhancement." https://omanscience.com/en/articles/looplut-3d-lookup-tables-with-progressive-region-refinement-for-real-time-4k-image-enhancement.
Chicago (author–date)
Ye, Yang, Jiajun Ma, Chen Wu, Wei Wang, Dianjie Lu, Guijuan Zhang, Linwei Fan, and Zhuoran Zheng. 2026. "LoopLUT: 3D Lookup Tables with Progressive Region Refinement for Real-Time 4K Image Enhancement." https://omanscience.com/en/articles/looplut-3d-lookup-tables-with-progressive-region-refinement-for-real-time-4k-image-enhancement.
Harvard
Ye, Y., Ma, J., Wu, C., Wang, W., Lu, D., Zhang, G., Fan, L. and Zheng, Z. (2026) 'LoopLUT: 3D Lookup Tables with Progressive Region Refinement for Real-Time 4K Image Enhancement', Available at: https://omanscience.com/en/articles/looplut-3d-lookup-tables-with-progressive-region-refinement-for-real-time-4k-image-enhancement.
Vancouver
Ye Y, Ma J, Wu C, Wang W, Lu D, Zhang G, et al. LoopLUT: 3D Lookup Tables with Progressive Region Refinement for Real-Time 4K Image Enhancement. https://omanscience.com/en/articles/looplut-3d-lookup-tables-with-progressive-region-refinement-for-real-time-4k-image-enhancement
IEEE
Y. Ye, J. Ma, C. Wu, W. Wang, D. Lu, G. Zhang, L. Fan, and Z. Zheng, "LoopLUT: 3D Lookup Tables with Progressive Region Refinement for Real-Time 4K Image Enhancement," https://omanscience.com/en/articles/looplut-3d-lookup-tables-with-progressive-region-refinement-for-real-time-4k-image-enhancement.