Evision

Mix.install([
  {:req, "~> 0.3"},
  {:evision, "~> 0.1"},
  {:kino, "~> 0.10.0"},
  {:nx, "~> 0.6"}
])

画像のダウンロード、表示

img =
  "https://upload.wikimedia.org/wikipedia/en/7/7d/Lenna_%28test_image%29.png"
  |> Req.get!()
  |> Map.get(:body)
  |> Evision.imdecode(Evision.Constant.cv_IMREAD_COLOR())

リサイズ

img
|> Evision.resize({600, 400})

グレースケール

img
|> Evision.cvtColor(Evision.Constant.cv_COLOR_BGR2GRAY())

ぼかし

img
|> Evision.blur({15, 15})

図形描画

img
|> Evision.rectangle({150, 120}, {225, 320}, {0, 0, 255},
  thickness: 12,
  lineType: Evision.Constant.cv_LINE_4()
)

文字描画

img
|> Evision.putText(
  "ohi",
  {250, 200},
  Evision.Constant.cv_FONT_HERSHEY_SIMPLEX(),
  2.5,
  {0, 255, 0},
  thickness: 5
)

一連処理

img
|> Evision.resize({600, 400})
|> Evision.cvtColor(Evision.Constant.cv_COLOR_BGR2GRAY())
|> Evision.blur({15, 15})
|> Evision.rectangle({150, 120}, {225, 320}, {0, 0, 255},
  thickness: 12,
  lineType: Evision.Constant.cv_LINE_4()
)
|> Evision.putText(
  "ohi",
  {250, 200},
  Evision.Constant.cv_FONT_HERSHEY_SIMPLEX(),
  2.5,
  {0, 0, 255},
  thickness: 5
)
|> dbg()

nxに変換

nximg =
  img
  |> Evision.cvtColor(Evision.Constant.cv_COLOR_BGR2RGB())
  |> Evision.Mat.to_nx()

nximg
|> Kino.Image.new()