Pngex.set_size

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

set_size(pngex, width, height)

Specs

set_size(t(), pos_int32(), pos_int32()) ::
  t() | {:error, [{:invalid_size, map()}]}

Sets image width and height.

Examples

iex> Pngex.new() |> Pngex.set_size(640, 480)
%Pngex{width: 640, height: 480}
iex> Pngex.new() |> Pngex.set_size(0, 480)
{:error, invalid_size: %{width: 0}}