Make chunky pixels the brute force way

chunky_pixels.rb

require 'rubygems'
require 'chunky_png'

orig = ChunkyPNG::Image.from_file('input.png')
rows = (orig.width / 10.0).ceil
cols = (orig.height / 10.0).ceil
canvas = ChunkyPNG::Canvas.new(rows * 10, cols * 10).replace(orig)

(0...rows).each do |row|
  x = row * 10
  (0...cols).each do |col|
    y = col * 10
    chunk = canvas.crop(x, y, 10, 10).resample(100, 100).crop(45, 45, 10, 10)
    canvas.replace!(chunk, x, y)
  end
end

canvas.crop(0, 0, orig.width, orig.height).save('output.png')

output.png