#!/usr/bin/env ruby

require 'rmagick'

def distance(first,second)
  first_f = first.map{|num| num.to_f} # 要素を実数に変換
  second_f = second.map{|num| num.to_f} # 要素を実数に変換
  first_f.zip(second_f).map{|f,s| (f-s)**2}.inject(:+)**(0.5)
end

color_set = [
  [0,0,0], [65535,65535,65535], [32768,0,0], [65535,0,0],
  [32768,32768,0], [65535,65535,0], [0,32768,0], [0,65535,0],
  [0,32768,32768], [0,65535,65535], [0,0,32768], [0,0,65535],
  [32768,0,32768], [65535,0,65535]
]

img = Magick::ImageList.new("pict.png")
img.rows.times do |row|
  img.columns.times do |column|
    pixel = img.pixel_color(column,row)
    distances = color_set.map{|color| distance(color, [pixel.red, pixel.green, pixel.blue])}
    color_hash = distances.zip(color_set).to_h
    min_dis_color = color_hash[distances.min] # 距離が一番近い色を取り出す
    new_color = Magick::Pixel.new(min_dis_color[0],min_dis_color[1],min_dis_color[2])
    img.pixel_color(column,row,new_color)
  end
end

img.write("animated_pict.png")