Pixelizing images with ChunkyPNG - Codebrawl

output.png

pixelize.rb

require 'chunky_png'

image = ChunkyPNG::Image.from_file('input.png')


BLOCK_SIZE = 10
(0...image.height).each_slice(BLOCK_SIZE) do |y_range|
  (0...image.width).each_slice(BLOCK_SIZE) do |x_range|
    block = x_range.map { |x| y_range.map { |y| [x, y] } }.flatten(1)
    r, g, b, a, size = 0, 0, 0, 0, block.size
    block.each do |x, y|
      m, n, o, p = ChunkyPNG::Color.to_truecolor_alpha_bytes(image[x, y])
      r, g, b, a = r + m, g + n, b + o, a + p
    end
    avg = ChunkyPNG::Color.rgba(r / size, g / size, b / size, a / size)
    block.each { |x, y| image[x, y] = avg }
  end
end

image.save('output.png')