Module: LookbookVisualTester::ImageTrimmer

Defined in:
lib/lookbook_visual_tester/services/image_trimmer.rb

Constant Summary collapse

DEFAULT_PADDING = 
10
BORDER_COLORS =

Pixels matching any of these colors are considered "empty" border and trimmed.

[
  ChunkyPNG::Color::WHITE,
  ChunkyPNG::Color::TRANSPARENT
].freeze

Class Method Summary collapse

Class Method Details

.border_pixel?(color) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/lookbook_visual_tester/services/image_trimmer.rb', line 55

def self.border_pixel?(color)
  BORDER_COLORS.include?(color)
end

.call(path, padding: DEFAULT_PADDING) ⇒ Object 



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# File 'lib/lookbook_visual_tester/services/image_trimmer.rb', line 14

def self.call(path, padding: DEFAULT_PADDING)
  image = ChunkyPNG::Image.from_file(path)

  min_x = image.width
  max_x = -1
  min_y = image.height
  max_y = -1

  image.height.times do |y|
    image.width.times do |x|
      next if border_pixel?(image[x, y])

      min_x = x if x < min_x
      max_x = x if x > max_x
      min_y = y if y < min_y
      max_y = y if y > max_y
    end
  end

  # No content found: keep the original image.
  return path if max_x < min_x

  content_width = max_x - min_x + 1
  content_height = max_y - min_y + 1
  new_width = content_width + (padding * 2)
  new_height = content_height + (padding * 2)

  trimmed = ChunkyPNG::Image.new(new_width, new_height, ChunkyPNG::Color::TRANSPARENT)

  image.height.times do |y|
    image.width.times do |x|
      next if x < min_x || x > max_x || y < min_y || y > max_y

      trimmed[x - min_x + padding, y - min_y + padding] = image[x, y]
    end
  end

  trimmed.save(path)
  path
end