# AIMatteRefine

> Turns a rough matte (matte input, e.g.

Turns a rough matte (matte input, e.g. AIRoto or a keyer) into a detailed alpha with hair and motion blur. ViTMatte builds a trimap from the rough matte (edge width); BiRefNet HR and RVM (people) work without one. Model Auto picks the best ViTMatte that fits the free GPU memory (never a research model). Temporal smoothing blends neighbour frames warped by optical flow. Runs in the AI worker. MatAnyone 2 (research pack, non-commercial use only: accept its licence in the panel first) is video matting: each chunk of Video Chunk frames starts from the rough matte of its first frame and follows it through time, for temporally stable hair and motion blur.

| Node | AIMatteRefine |
|---|---|
| Menu | AI › AIMatteRefine |
| **Names in each format** | |
| .oink comp (JSON) | `"type": "OC_N_aimatterefine"` |
| .nk script | none: written as an Oink node |
| Python | `nuke.createNode("OC_N_aimatterefine")` |
| Assistant (MCP) | `create_node(type="AIMatteRefine")` |
| Tab search | `aimatterefine`, or its initials `aimr` |

![AIMatteRefine properties](/shots/nodes/aimatterefine@2x.webp)

## Inputs and outputs

| Port | Name | Type |
|---|---|---|
| input 0 | Image | image |
| input 1 | matte | image |
| output 0 | Image | image |

## Knobs

Panel tab **Aimatterefine**, in panel order.

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `model` | model | menu | `AUTO` | AUTO (Auto (by free GPU memory)), VITMATTE_BASE (ViTMatte base), VITMATTE_SMALL (ViTMatte small), BIREFNET (BiRefNet HR), RVM (RVM (humans)), MATANYONE2 (MatAnyone 2 (research pack, non-commercial)) |  |  |
| `matte_channel` | matte channel | menu | `alpha` | alpha, red, green, blue |  | Channel of the matte input holding the rough alpha |
| `edge_width` | edge width | float | `20` | 1 to 200 |  | Width of the band around the rough edge the model may change (px) |
| `strength` | strength | float | `1` | 0 to 1 |  | 0 = rough matte, 1 = fully refined (inside the edge band) |
| `keep_known` | keep known | bool | `true` |  |  | BiRefNet / RVM: keep the rough matte's solid inside and outside |
| `temporal` | temporal smoothing | float | `0` | 0 to 1 |  | Blend with neighbouring frames' refined alpha (0 = off) |
| `temporal_radius` | temporal frames | float | `2` | 1 to 4 (integer) |  | Neighbours on each side |
| `temporal_method` | temporal method | menu | `flow` | flow (optical flow), blend |  |  |
| `tile_size` | tile size | float | `1024` | 0 to 4096 (integer) |  | ViTMatte tile size in px (0 = whole frame at once) |
| `video_chunk` | video chunk (MatAnyone 2) | float | `24` | 2 to 200 (integer) |  | MatAnyone 2: frames per chunk; each chunk starts from the rough matte of its first frame (project range aligned) |
| `video_size` | video size (MatAnyone 2) | float | `1080` | 256 to 4096 (integer) |  | MatAnyone 2: shortest side it works at (bigger plates are resized inside; more = finer hair, more VRAM) |
| `output` | output | menu | `alpha` | alpha, premult (premultiplied), unmix (unmixed fg), matte |  |  |

### Other knobs (Python, .nk and the assistant; not on the panel)

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `gl_color` | Viewer Controls Color | float ×3 | `0, 0, 0` | 0 to 1 |  |  |
| `postage_stamp_frame` | Static Frame | int | `1` | -2147483648 to 2147483647 |  |  |
| `lifetimeStart` | Lifetime Start | int | `0` | -2147483648 to 2147483647 |  |  |
| `lifetimeEnd` | Lifetime End | int | `100` | -2147483648 to 2147483647 |  |  |
| `useLifetime` | Use Lifetime | boolean | `false` |  |  |  |
| `cached` | Cached | boolean | `false` |  |  |  |
| `bookmark` | Bookmark | boolean | `false` |  |  |  |
| `dope_sheet` | Dope Sheet | boolean | `false` |  |  |  |
| `clone_group` | Clone Group | string |  |  |  |  |
| `link_source` | Link Source | string |  |  |  |  |
| `link_overrides` | Link Overrides | string |  |  |  |  |
| `split_views` | Split Views | string |  |  |  |  |

## Examples

Open these from **Help › Examples…**, or from the **?** menu in this node's Properties panel.

- **AIMatteRefine: hair-quality edges from a rough matte** (`examples/ai/aimatterefine_edges.oink`): A rough matte (the CandleGlass alpha, eroded by a Blur) goes into the matte input; AIMatteRefine (ViTMatte) rebuilds the soft edge from the plate.


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Sources: opencomp_core/nodes/ai/aimatte.py, opencomp_electron/src/components/properties/knobSchema.ts, opencomp_core/nodes/help/aimatterefine.md