Export Photoshop Layers into power-of-two sized images.

psd_export_layers_power_of_two.rb

require 'json'
require 'psd'

def is_power_of_two(x)
  n = x.to_i
  while (((x % 2) == 0) && x > 1)
    x = x/2
  end
  x == 1 && n != 1
end

file = ARGV[0] || './characters.psd'
psd = PSD.new(file, parse_layer_images: true)
psd.parse!

file_list = []
psd.tree.descendant_layers.each do |layer|
  original = layer.image.to_png
  size = [original.width, original.height].max
  while !is_power_of_two(size)
    size = size + 1
  end

  power_of_two = ChunkyPNG::Image.new(size, size, ChunkyPNG::Color::TRANSPARENT)
  original.pixels.each_with_index do |color, i|
    x = i % original.width
    y = i / original.width
    power_of_two.set_pixel(x,y,color)
  end
  
  power_of_two.save("images/#{layer.path.gsub('/', '-')}.png")
  file_list << filename
end

File.open('resources.json', 'w+') do |f|
  f.write(file_list.to_json)
end

Hi - this is just what Im looking for! I cant quite figure out how to use the .rb file in photoshop though - would you have any tips? many thanks!