adithya-balaji/rfdetr-cpp-nano

RF-DETR Nano — GGUF for rfdetr.cpp

GGUF-format weights of Roboflow RF-DETR Nano (detection variant) for use with rfdetr.cpp, a C++/ggml implementation that matches the upstream PyTorch model on CPU.

This repo contains all four standard quantizations of this variant. F16 is the recommended default — same accuracy as F32, 1.85× smaller, and typically the fastest on modern CPUs thanks to ggml's F32×F16 matmul fast path.

Available files

File	Quant	Size (MB)	Recall @ IoU 0.5	Recall @ IoU 0.95	Mean |Δscore|	Latency (median ms, T=8)
rfdetr-nano-f32.gguf	F32	112.7	1.0000	1.0000	0.0012	55.8
rfdetr-nano-f16.gguf ← recommended	F16	60.5	1.0000	1.0000	0.0007	49.6
rfdetr-nano-q8_0.gguf	Q8_0	36.0	1.0000	1.0000	0.0053	59.3
rfdetr-nano-q4_K.gguf	Q4_K	29.7	0.9495	0.8593	0.0311	60.6

All accuracy numbers above are computed against the upstream PyTorch reference (rfdetr 1.9.0) on 7 images (000000000139.jpg, 000000000632.jpg, 000000039769.jpg, 000000087038.jpg, 000000252219.jpg, 000000397133.jpg, bus.jpg) at threshold 0.5. Latency is measured separately with rfdetr-cli bench (8 iters + 3 warmup) at T=8 threads on a single Intel Core i7-12800HX, on tests/fixtures/ci/test_image.jpg.

Architecture

• Backbone: DINOv2-small
• Input resolution: 384×384
• Patch size: 16
• Decoder layers: 2
• Object queries: 300
• Task: object detection (boxes only)

Quantization notes

• F32 — full-precision reference, ~120 MB. Bit-exact PyTorch parity.
• F16 — matmul-multiplicand weights only; LayerNorms, conv kernels, embeddings, biases, and layer-scale gammas stay F32. Lossless on this model and consistently the fastest variant on CPU.
• Q8_0 — best size/accuracy tradeoff under F16; ~3× smaller than F32 with effectively identical detections.
• Q4_K — smallest practical quant. Rows with ne[0] % 256 != 0 (the decoder's 128-dim MLP halves, 60 tensors) silently fall back to Q8_0 per ggml's quantizer logic — net compression is still ~3.8× over F32. Use only when the size budget is tight; expect a measurable Recall@0.95 drop relative to F16/Q8_0 (see file table above).

Compatibility

These GGUFs stamp rfdetr.preprocess.resize_mode = "bilinear_no_antialias", matching RF-DETR 1.9's antialias-free float bilinear resize (align_corners=false, half-pixel coordinates, no intermediate uint8 rounding). rf-detr.cpp treats this key as optional: GGUFs that predate this metadata (no resize_mode key) keep using the legacy stb-based resize path, so older files continue to produce their original outputs unchanged. An unrecognized resize_mode value is rejected rather than guessed.

Keypoint-preview inference is not supported. rf-detr.cpp does not implement the keypoint output head; this repository only serves box detection outputs.

Usage

# 1. Clone + build rfdetr.cpp
git clone https://github.com/adithyab94/rf-detr.cpp
cd rf-detr.cpp
cmake -B build -DRFDETR_BUILD_CLI=ON && cmake --build build -j

# 2. Download a quant (F16 recommended)
hf download adithya-balaji/rfdetr-cpp-nano rfdetr-nano-f16.gguf --local-dir models/

# 3. Run detection
build/bin/rfdetr-cli detect \
    --model models/rfdetr-nano-f16.gguf \
    --input my_image.jpg \
    --threshold 0.5 --threads 8 \
    --output detections.json

Accuracy methodology

All accuracy metrics are computed against the upstream PyTorch reference (rfdetr 1.9.0) on 7 images (000000000139.jpg, 000000000632.jpg, 000000039769.jpg, 000000087038.jpg, 000000252219.jpg, 000000397133.jpg, bus.jpg) at threshold 0.5. Each detection match uses greedy Hungarian-style assignment by IoU (≥ 0.5 lenient, ≥ 0.95 strict) with class equality required.

See BENCHMARK.md and benchmarks/results/accuracy_sweep.json for the full sweep across the (variant × quant) cells.

Provenance

• Source project: Roboflow RF-DETR
• Upstream package: rfdetr==1.9.0
• Converted with rfdetr.cpp at commit fbef9387bed3
• Checkpoint: official pretrained rfdetr-nano weights (downloaded by the rfdetr package on first use)

Checksums (SHA-256)

Also available as SHA256SUMS in this repo.

179a744d083eb6aa611de1e258b12696e3f85a2c530c2b348a4fc4115c016df2  rfdetr-nano-f32.gguf
aa1c065e0069e552b715deb651caa5c76300eec4a87c76f1ef598413a0915ef8  rfdetr-nano-f16.gguf
6cf9cc1684ee6f42a6a044a5e3428b5269904bccd28942f99badd9248221c695  rfdetr-nano-q8_0.gguf
b7fc9e4a455e0623a1f0008c1ba9841a0cbc5eb07fb2f8125830e59c3694728c  rfdetr-nano-q4_K.gguf

License

Apache-2.0 — matches the upstream rfdetr license.