# Source Registry

## Source #1
- **Title**: LiteSAM: Lightweight and Robust Feature Matching for Satellite and Aerial Imagery
- **Link**: https://www.mdpi.com/2072-4292/17/19/3349
- **Tier**: L1
- **Publication Date**: 2025-10-01
- **Timeliness Status**: ✅ Currently valid
- **Version Info**: LiteSAM v1 (6.31M params)
- **Target Audience**: UAV satellite-aerial matching at 100-2000m altitude
- **Research Boundary Match**: ✅ Full match
- **Summary**: Proposes LiteSAM, a lightweight semi-dense matcher achieving RMSE@30=17.86m on UAV-VisLoc with 6.31M params and 83.79ms on RTX 3090. Outperforms EfficientLoFTR in hit rate while using 2.4x fewer parameters.
- **Related Sub-question**: 1, 2, 3

## Source #2
- **Title**: LiteSAM GitHub Repository
- **Link**: https://github.com/boyagesmile/LiteSAM
- **Tier**: L1
- **Publication Date**: 2025-09 (estimated from paper)
- **Timeliness Status**: ✅ Currently valid
- **Version Info**: 4 commits, 5 stars, 0 forks
- **Target Audience**: Researchers and developers
- **Research Boundary Match**: ✅ Full match
- **Summary**: Official code repository. Pretrained weights on Google Drive. Built upon EfficientLoFTR. PyTorch only, no ONNX/TensorRT support. Very early-stage.
- **Related Sub-question**: 4, 7

## Source #3
- **Title**: Efficient LoFTR: Semi-Dense Local Feature Matching with Sparse-Like Speed (CVPR 2024)
- **Link**: https://github.com/zju3dv/EfficientLoFTR
- **Tier**: L1
- **Publication Date**: 2024-03
- **Timeliness Status**: ✅ Currently valid
- **Version Info**: CVPR 2024, 964 stars
- **Target Audience**: Computer vision researchers and practitioners
- **Research Boundary Match**: ✅ Full match
- **Summary**: Semi-dense matcher, 15.05M params, ~2.5x faster than LoFTR. TensorRT adaptation exists. HuggingFace integration. ONNX export available. Achieves 27ms at 640×480 with FP16.
- **Related Sub-question**: 1, 2, 3, 4

## Source #4
- **Title**: LightGlue-ONNX
- **Link**: https://github.com/fabio-sim/LightGlue-ONNX
- **Tier**: L1
- **Publication Date**: 2023-ongoing
- **Timeliness Status**: ✅ Currently valid
- **Version Info**: Active development, FP16 on Turing GPUs
- **Target Audience**: Developers deploying LightGlue on edge/production
- **Research Boundary Match**: ✅ Full match
- **Summary**: ONNX/TensorRT export for LightGlue. 2-4x speedup. FP16 works on RTX 2060 (Turing). Well-tested production-ready path.
- **Related Sub-question**: 2, 4

## Source #5
- **Title**: LoFTR_TRT — TensorRT adaptation of LoFTR
- **Link**: https://github.com/Kolkir/LoFTR_TRT
- **Tier**: L2
- **Publication Date**: 2022-ongoing
- **Timeliness Status**: ⚠️ Based on original LoFTR, not EfficientLoFTR
- **Version Info**: 105+ stars
- **Target Audience**: Developers deploying LoFTR on embedded/edge
- **Research Boundary Match**: ⚠️ Partial overlap — LoFTR architecture, not EfficientLoFTR
- **Summary**: Demonstrates LoFTR family can be exported to ONNX/TensorRT. Knowledge distillation approach for coarse-only variant. Applicable pattern for EfficientLoFTR.
- **Related Sub-question**: 4

## Source #6
- **Title**: EfficientLoFTR HuggingFace Model
- **Link**: https://huggingface.co/zju-community/efficientloftr
- **Tier**: L1
- **Publication Date**: 2024
- **Timeliness Status**: ✅ Currently valid
- **Version Info**: Integrated with HuggingFace Transformers
- **Target Audience**: ML practitioners
- **Research Boundary Match**: ✅ Full match
- **Summary**: Official HuggingFace integration. 27ms at 640×480 with mixed precision. Surpasses SuperPoint+LightGlue in speed and accuracy.
- **Related Sub-question**: 2, 3, 4

## Source #7
- **Title**: DALGlue — Efficient image matching for UAV visual navigation
- **Link**: https://www.nature.com/articles/s41598-025-21602-5
- **Tier**: L1
- **Publication Date**: 2025
- **Timeliness Status**: ✅ Currently valid
- **Version Info**: 2025 publication
- **Target Audience**: UAV visual navigation researchers
- **Research Boundary Match**: ✅ Full match
- **Summary**: DALGlue outperforms LightGlue by 11.8% MMA on MegaDepth. Uses dual-tree complex wavelet transform. AUC@5°/10°/20° = 57.01/73.00/84.11. Alternative sparse matcher.
- **Related Sub-question**: 1

## Source #8
- **Title**: LightGlue rotation invariance issue #64
- **Link**: https://github.com/cvg/LightGlue/issues/64
- **Tier**: L2
- **Publication Date**: 2023
- **Timeliness Status**: ✅ Still relevant
- **Version Info**: Confirmed limitation
- **Target Audience**: LightGlue users
- **Research Boundary Match**: ✅ Full match
- **Summary**: LightGlue confirmed NOT rotation-invariant. Same limitation applies to all LoFTR-family matchers including LiteSAM and EfficientLoFTR.
- **Related Sub-question**: 5
