---
license: apache-2.0
tags:
  - onnx
  - background-removal
  - salient-object-detection
  - segmentation
  - qtmesheditor
library_name: onnx
pipeline_tag: image-segmentation
---

# U²-Net — ONNX (background removal)

**U²-Net** (Qin et al., *"U²-Net: Going Deeper with Nested U-Structure for
Salient Object Detection"*, 2020) as the standard `u2net.onnx` used by
[rembg](https://github.com/danielgatis/rembg) — Apache-2.0. All credit to the
U²-Net authors.

Mirrored for **[QtMeshEditor](https://github.com/fernandotonon/QtMeshEditor)**
(epic #764), where it isolates the subject before single-image 3D
reconstruction: `qtmesh generate3d --remove-bg`, the GUI "Remove background"
checkbox, and the `remove_bg` MCP arg.

> The file QtMeshEditor downloads at runtime lives in the shared
> [`fernandotonon/QtMeshEditor-models`](https://huggingface.co/fernandotonon/QtMeshEditor-models)
> repo under `rembg/`. This repo is the standalone model card + mirror.

## I/O

`[1,3,320,320]` float NCHW → `[1,1,320,320]` saliency in `[0,1]`.

QtMeshEditor's usage notes: composite the masked subject over **gray-128**
for TripoSR (white reconstructs as a wall) but over **white** for TripoSG
(its reference pipeline), then crop/re-pad to a 0.85 foreground ratio.

## License

Apache-2.0 (upstream U²-Net). Credit: Xuebin Qin et al.