Add vibrance options

lib/image.ex

@@ -8656,22 +8656,22 @@ defmodule Image do
   def vibrance(%Vimage{} = image, vibrance, options \\ []) when is_multiplier(vibrance) do
     use Image.Math
 
-    threshold = Keyword.get(options, :threshold, 100)
-
-    identity = Operation.identity!()
-    h2 = 255
-    h3 = 6 * identity / h2
-    h4 = 2 / (1 + exp!(-h3)) - 1
-    h5 = h3 / 6
-    h6 = h4 - h5
-    h7 = vibrance
-    h8 = h5 + h7 * h6
-
-    with_colorspace(image, :lch, fn image ->
-      g5 = h2 * image[1] / threshold
-      g7 = threshold * Operation.maplut!(g5, h8)
-      Image.join_bands([image[0], g7, image[2]])
-    end)
+    with {:ok, options} <- Options.Vibrance.validate_options(options) do
+      identity = Operation.identity!()
+      h2 = 255
+      h3 = 6 * identity / h2
+      h4 = 2 / (1 + exp!(-h3)) - 1
+      h5 = h3 / 6
+      h6 = h4 - h5
+      h7 = vibrance
+      h8 = h5 + h7 * h6
+
+      with_colorspace(image, :lch, fn image ->
+        g5 = h2 * image[1] / options.threshold
+        g7 = options.threshold * Operation.maplut!(g5, h8)
+        Image.join_bands([image[0], g7, image[2]])
+      end)
+    end
   end
 
   @doc """

lib/image/options/vibrance.ex

@@ -0,0 +1,66 @@
+defmodule Image.Options.Vibrance do
+  @moduledoc """
+  Options and option validation for `Image.vibrance/2`.
+
+  """
+
+  @typedoc """
+  Options applicable to Image.vibrance/3
+
+  """
+  @type vibrance_option :: {:threshold, pos_integer()}
+
+  @typedoc """
+  Options list for Image.vibrance/3
+
+  """
+  @type vibrance_options :: [vibrance_option()] | map()
+
+  @default_vibrance_threshold 70
+
+  @doc false
+  def default_vibrance_threshold do
+    @default_vibrance_threshold
+  end
+
+  @doc """
+  Validate the options for `Image.vibrance/3`.
+
+  See `t:Image.Options.Vibrance.vibrance_options/0`.
+
+  """
+  def validate_options(options) when is_list(options) do
+    options = Keyword.merge(default_options(), options)
+
+    case Enum.reduce_while(options, options, &validate_option(&1, &2)) do
+      {:error, value} ->
+        {:error, value}
+
+      options ->
+        {:ok, Map.new(options)}
+    end
+  end
+
+  def validate_options(%{} = options) do
+    {:ok, options}
+  end
+
+  defp validate_option({:threshold, threshold}, options)
+      when is_integer(threshold) and threshold in 1..100//1 do
+    {:cont, options}
+  end
+
+  defp validate_option(option, _options) do
+    {:halt, {:error, invalid_option(option)}}
+  end
+
+  defp invalid_option(option) do
+    "Invalid option or option value: #{inspect(option)}"
+  end
+
+  defp default_options do
+    [
+      threshold: @default_vibrance_threshold
+    ]
+  end
+end