---
license: apache-2.0
library_name: bcdl
tags:
- rdk-s100
- rdk-s100p
- d-robotics
- bpu
- hbm
- depth-estimation
---

# LingBot-Depth for RDK S100/S100P — RGB-D depth refinement

Compiled BPU models (`.hbm`) for the **D-Robotics RDK S100 / S100P**, ready to
load — no ONNX export, no calibration, no `hb_compile`. Built and measured with
[**BCDL**](https://github.com/ruisv/bcdl), a C++17 inference and media library
for the RDK S-series with Python bindings.

Upstream: [lingbot-depth](https://github.com/Robbyant/lingbot-depth) v0.5 (MDM, DINOv2 ViT-L/14 RGB-D encoder)

> [!TIP]
> **Redistributable, including commercially.** The licence chain was checked on
> the code, the pretrained weights it started from, and the data it was trained
> on — all three, because a permissive repository badge does not by itself say
> anything about the weights. See [Licence](#licence).

## Files

| file | what it is |
|---|---|
| `lingbot_depth_v05_int16_nashm.hbm` | all-int16, 480x640 RGB + depth — 1015.3 MB |

## Measured on an S100P

| stage | latency | throughput |
|---|---|---|
| refinement | 1453 ms | 0.69 FPS |

`hrt_model_exec perf`, one thread, minimum of three runs, on a board first gated
against its own previously recorded numbers. **BPU time only** — CPU
pre/post-processing is on top and is listed per task in BCDL's
[benchmark results](https://github.com/ruisv/bcdl/blob/main/benchmarks/RESULTS.md).

## Use it

```bash
conda install -c https://mirrors.ruis.ai/conda -c conda-forge bcdl
```

```python
import bcdl
engine = bcdl.Engine("lingbot_depth_v05_int16_nashm.hbm")
print(engine.input_shape(0), engine.output_shape(0))
```

Each task has a decoder in BCDL that turns those raw outputs into boxes,
keypoints, masks, disparity or text — see the
[Python API](https://github.com/ruisv/bcdl/blob/main/docs/API.md)
([中文](https://github.com/ruisv/bcdl/blob/main/docs/API.zh.md)).

## What to know before deploying

**This refines depth, it does not estimate it.** Give it a depth map you already
have — stereo, ToF, noisy and full of holes — plus the aligned RGB frame, and it
returns hole-filled metric depth with a per-pixel trust mask. It composes with a
stereo or depth camera rather than competing with one.

**It is a seconds-per-frame model, an order of magnitude slower than anything
else here.** Use it to refine a keyframe on demand — a grasp pose, a mapping
snapshot — not as a stage in a video loop. The cost is the attention score
matrix, quadratic in a sequence of 1 + 2N tokens, moving ~23 GB of DDR per frame.

**Only the int16 build is published, and int8 is deliberately absent.** int8 PTQ
does not survive a 24-layer ViT-L: it compiles cleanly and returns a well-formed
depth map whose dynamic range has collapsed — 2.9-13.8 m against the float
model's 0.97-45.8 m, 233% mean absolute relative error. Publishing it would just
be handing somebody a trap.

The deployed graph also keeps every depth token, where upstream drops the ones
whose patch holds no valid reading — that masking makes the sequence length
depend on the data and cannot be compiled statically. Measured cost of keeping
them: 0.06% mean absolute relative error, 0.9999 mask IoU, on scenes that are
87-100% valid. Very sparse input depth was not measured.

## Licence

Apache-2.0 on the code and the weights; the DINOv2 backbone is Apache-2.0 too.

**BCDL itself is Apache-2.0 and is unrelated to these terms** — it is a
general-purpose runtime that loads any `.hbm`. The licence above constrains
*these weights and this compiled artefact*.

The conversion recipe — ONNX export, calibration, `hb_compile` config and the
acceptance numbers — is public in
[**bcdl-model-zoo**](https://github.com/ruisv/bcdl-model-zoo), so this build can
be reproduced or retargeted rather than taken on trust.