Module: Qrio::ImageDumper

Included in:
Qr
Defined in:
lib/qrio/image_dumper.rb

Overview

this module contains the code to dump images of QR decoding progress. useful for debugging or those curious about the detection / decoding algorithms

Instance Method Summary collapse

Instance Method Details

#color(name) ⇒ Object 



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# File 'lib/qrio/image_dumper.rb', line 86

def color(name)
  rgb = {
    :green   => [  0, 255,   0],
    :red     => [255,   0,   0],
    :magenta => [227,  91, 216],
    :cyan    => [  0, 255, 255],
  }[name]

  ChunkyPNG::Color.rgb(*rgb)
end

#save_image(filename, options = {}) ⇒ Object 



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# File 'lib/qrio/image_dumper.rb', line 6

def save_image(filename, options={})
  if matrix = @extracted_matrix
    # extracted matrix is already cropped
    options[:crop] = false
    @features = {
      :candidates      => {},
      :matches         => @translated_matches,
      :finder_patterns => @sampling_grid.finder_patterns
    }
  else
    matrix = @input_matrix
    @features = {
      :candidates      => @candidates,
      :matches         => @matches,
      :finder_patterns => @finder_patterns
    }
  end

  save_to_image(matrix, filename, options)
end

#save_to_image(matrix, filename, options = {}) ⇒ Object 



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# File 'lib/qrio/image_dumper.rb', line 27

def save_to_image(matrix, filename, options={})
  png = ChunkyPNG::Image.new(
    matrix.width,
    matrix.height,
    ChunkyPNG::Color::WHITE
  )

  (0..(matrix.width - 1)).to_a.each do |x|
    (0..(matrix.height - 1)).to_a.each do |y|
      png[x, y] = ChunkyPNG::Color::BLACK if matrix[x, y]
    end
  end

  if options[:annotate].include?(:candidates)
    @features[:candidates][:horizontal].each do |hmatch|
      png.rect(*hmatch.to_coordinates, color(:green))
    end

    @features[:candidates][:vertical].each do |vmatch|
      png.rect(*vmatch.to_coordinates, color(:magenta))
    end
  end

  if options[:annotate].include?(:matches)
    @features[:matches][:horizontal].each do |hmatch|
      png.rect(*hmatch.to_coordinates, color(:green))
    end

    @features[:matches][:vertical].each do |vmatch|
      png.rect(*vmatch.to_coordinates, color(:magenta))
    end
  end

  if options[:annotate].include?(:finder_patterns)
    @features[:finder_patterns].each do |finder_pattern|
      png.rect(*finder_pattern.to_coordinates, color(:red))
    end
  end

  if options[:annotate].include?(:angles)
    @sampling_grid.angles[0, 100].each do |angle|
      png.line_xiaolin_wu(*angle.to_coordinates, color(:cyan))
    end
  end

  if options[:annotate].include?(:alignment_patterns)
    png.rect(*@alignment_pattern.to_coordinates, color(:magenta))
  end

  if options[:annotate].include?(:extracted_pixels)
    @sampling_grid.extracted_pixels do |x, y|
      png.circle(x, y, 1, color(:cyan))
    end
  end

  png = png.crop(*@qr_bounds.to_point_size) if options[:crop]
  png.save(filename, :fast_rgba)
end