module PalletePNG

Constants

VERSION

Public Class Methods

to_transparency(image_data) click to toggle source

@param [String] image_data The PNG image data @return [String] The PNG image data @raise [PalletePNG::Image::NotPNG] if image_data is not a PNG image @example

image_data = PalletePNG.to_transparency File.binread('pallete-based-w-transparency.png')

# File lib/pallete_png.rb, line 10
def self.to_transparency(image_data)
  begin
    image = Image.new image_data
  rescue ChunkyPNG::SignatureMismatch
    raise Image::NotPNG
  end

  # Returns the raw image data if image is not a pallete-based PNG with transparency
  return image_data unless image.pallete_based? && image.transparency_chunk?

  image.to_truecolor_alpha
end