SCARF: A Scene-Adaptive Depth-Guided G-3DGS Encoder Accelerator with Semantic Reuse and Fused Dataflow

Zirui Ma · Zhihua Fan · Haibin Wu · Wenxing Li · Fulin Zhang · Dongrui Fan · Xiaochun Ye · Wenming Li

Institute of Computing Technology, Chinese Academy of Sciences · University of Chinese Academy of Sciences

MICRO 2026

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ACM Artifacts Evaluated Functional badgeFunctional
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Bedroom scene used for Gaussian similarity analysis in the paper
Scene with one example tile
Encoder features · schematic
Query Q · 16-bit LSH Hamming distance ≤ threshold Cached C · 16-bit LSH Cached depth anchor dc
Same image pixels · corner probes
Semantic match · cached depth
Depth candidates · same global set
BaselineD
Cache hitD/R
A miss retains all D candidates.
Cross-view sampling → cost volume → U-Net → depth
4 × 4 TILE · CORNER PROBESOriginal S2 depth + Gaussian adaptor
L0Low feature varianceRepresentative
L1Else, low depth spreadDepth-weighted
FullElse, irregular tilePer-pixel adaptor
Only non-probe pixels follow the selected path.

Abstract

Depth-guided G-3DGS encoders reconstruct scenes directly from multi-view images without per-scene optimization. SCARF addresses two sources of redundant encoder work: FSDR reuses depth information across semantically similar features, while SAES selects a Gaussian generation path from local scene regularity before unnecessary primitives are created. A fused accelerator implements both mechanisms and delivers a 2.94-fold geometric-mean end-to-end speedup on the evaluated workloads, with maximum PSNR degradation below 0.072 percent.

Dataflow and Architecture

Complete SCARF dataflow: feature extraction, FSDR depth search, probe-driven SAES materialization, and Gaussian conversion.

FSDR: Feature Similarity Depth Reuse

FSDR matches a query signature against the semantic cache. A hit selects D/R original candidates around the cached depth; a miss retains all D. Both paths use the original depth predictor and update the cache.

SAES: Scene-Adaptive Early Sparsification

SAES computes four corner probes with the original depth predictor and Gaussian adaptor. Non-probe pixels use L0 soft assignment and moment matching for low feature variance, otherwise L1 depth-weighted aggregation for low depth spread, otherwise full per-pixel computation.
SCARF architecture with FSDR cache, matrix-vector unit, shared compute array, local buffers, pipeline controller, and Gaussian generation unit.

Qualitative Visualization

Quality change
FSDR worst-view quality change
Stage latency
FSDR worst-view stage latency
Rendered view
FSDR worst-view rendered view
RGB error
FSDR worst-view RGB errorOriginal RGB error color scale

Quantitative Comparison

Faster end to end.

End-to-end speedup over Orin NX for nine model-dataset pairs and normalized stage latency breakdown.

Presentation

Opening slide of the SCARF conference presentation videoXIAOHONGSHU ↗

BibTeX

@inproceedings{ma2026scarf,
  author    = {Zirui Ma and Zhihua Fan and Haibin Wu and Wenxing Li and
               Fulin Zhang and Dongrui Fan and Xiaochun Ye and Wenming Li},
  title     = {{SCARF}: A Scene-Adaptive Depth-Guided {G-3DGS}
               Encoder Accelerator with Semantic Reuse and Fused Dataflow},
  booktitle = {2026 59th IEEE/ACM International Symposium
               on Microarchitecture (MICRO)},
  year      = {2026},
  pages     = {2512--2528},
  publisher = {IEEE},
  doi       = {10.1109/MICRO67795.2026.00172},
  url       = {https://doi.org/10.1109/MICRO67795.2026.00172}
}