Pngex.set_type

You're seeing just the function set_type, go back to Pngex module for more information.
Link to this function

set_type(pngex, type)

Specs

set_type(t(), color_type()) :: t() | {:error, [{:invalid_type, any()}]}

Sets color type.

Examples

iex> Pngex.new() |> Pngex.set_type(:gray)
%Pngex{type: :gray}
iex> Pngex.new() |> Pngex.set_type(:monotone)
{:error, invalid_type: :monotone}