Background Removal

> #### Livebook Desktop users {: .info} > > Livebook Desktop launches as a GUI app and does not inherit your terminal’s PATH. If Mix.install below fails with “cargo: command not found” or similar, your Rust toolchain isn’t visible to Livebook Desktop. Fix by creating ~/.livebookdesktop.sh with at minimum: > > sh > export PATH="$HOME/.cargo/bin:$PATH" > # If you use mise/asdf, also activate them here. > > > Restart Livebook Desktop after editing the file. See the project README for details on which toolchains are needed.

Mix.install([
  {:image_vision, "~> 0.2"},
  {:kino, "~> 0.14"},
  # Background removal uses an ONNX model via Ortex.
  {:ortex, "~> 0.1"}
])

Image.Background removes the background from any image — class-agnostic salient-object detection. The model decides what’s the subject and isolates it. Powered by BiRefNet lite (MIT, ~210 MB; downloads on first call).

Upload an image

input = Kino.Input.image("Image with a clear foreground subject")

image =
  input
  |> Kino.Input.read()
  |> Image.from_kino!()

Foreground mask

mask = Image.Background.mask(image)

Kino.Layout.grid(
  [
    Kino.Layout.grid([image, Kino.Markdown.new("**Original**")], boxed: true),
    Kino.Layout.grid([mask, Kino.Markdown.new("**Foreground mask**")], boxed: true)
  ],
  columns: 2
)

Cutout (background made transparent)

{:ok, cutout} = Image.Background.remove(image)

Kino.Layout.grid(
  [
    Kino.Layout.grid([image, Kino.Markdown.new("**Original**")], boxed: true),
    Kino.Layout.grid([cutout, Kino.Markdown.new("**Cutout (transparent BG)**")], boxed: true)
  ],
  columns: 2
)

Composite onto a different background

The cutout has an alpha channel, so you can composite it over any other image with Image.compose/2. Try generating a coloured background and pasting the cutout on top:

{:ok, backdrop} =
  Image.new(Image.width(cutout), Image.height(cutout), color: [220, 240, 255])

{:ok, recomposed} = Image.compose(backdrop, cutout)

recomposed