chunky pixelizer

output.png

pixelize.rb

#!/usr/bin/env ruby
require 'chunky_png'

# A chunky monkey patch... am I going to get sued by Ben and Jerry?
class ChunkyPNG::Image < ChunkyPNG::Canvas
  def pixelize_area!(vector)
    red_vals = []
    green_vals = []
    blue_vals = []
    vector.each do |pixel|
      red_vals << ChunkyPNG::Color.r(self[pixel.x, pixel.y])
      green_vals << ChunkyPNG::Color.g(self[pixel.x, pixel.y])
      blue_vals << ChunkyPNG::Color.b(self[pixel.x, pixel.y])
    end
    pixel_color = ChunkyPNG::Color.rgb(avg(red_vals),avg(green_vals),avg(blue_vals))
    self.rect(vector.min.x, vector.min.y, vector.max.x, vector.max.y, pixel_color, pixel_color)
    return self
  end
  
  def pixelize!(blocksize)
    grid_x = (0..self.dimension.width).reject{|x| x%blocksize != 0}
    grid_y = (0..self.dimension.height).reject{|y| y%blocksize != 0}
    grid_x.each_with_index do |x,i|
      grid_y.each_with_index do |y,j|
        next_x = [grid_x[i+1], self.dimension.width-1].reject{|i| i == nil}.min
        next_y = [grid_y[j+1], self.dimension.height-1].reject{|i| i == nil}.min
        width = next_x - x
        height = next_y - y
        unless width <= 0 || height <= 0
          va = []
          (x..next_x).each do |vx|
            (y..next_y).each do |vy|
              va << [vx, vy]
            end
          end
          vector = ChunkyPNG::Vector(*va)
          self.pixelize_area!(vector)
        end
      end
    end
    return self
  end
  
  private
  
    def avg(array)
      ((array.reduce{|sum,n| sum+n})/(array.size)).to_i
    end
end

image = ChunkyPNG::Image.from_file(ARGV[0])
image.pixelize!(ARGV[2] ? ARGV[2].to_i : 10)
image.save(ARGV[1])
puts "done"