Class: Naiso::SplitPointDetector

Inherits:
Object
  • Object
show all
Defined in:
lib/naiso/split_point_detector.rb

Overview

분할점 감지기

Instance Method Summary collapse

Constructor Details

#initialize(analyzer, config) ⇒ SplitPointDetector

Returns a new instance of SplitPointDetector.



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# File 'lib/naiso/split_point_detector.rb', line 8

def initialize(analyzer, config)
  @analyzer = analyzer
  @config = config
end

Instance Method Details

#find_background_transitions(variance_threshold: 5.0, min_uniform_height: 20, color_diff_threshold: 15.0) ⇒ Object

배경색 전환 지점 감지



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# File 'lib/naiso/split_point_detector.rb', line 83

def find_background_transitions(
  variance_threshold: 5.0,
  min_uniform_height: 20,
  color_diff_threshold: 15.0
)
  img_array = @analyzer.img_array
  variance = @analyzer.variance
  height = @analyzer.height

  transitions = []

  (min_uniform_height...(height - min_uniform_height)).each do |y|
    # 위아래가 모두 단색인지 확인
    above_uniform = variance[(y - min_uniform_height)...y].to_a.all? { |v| v < variance_threshold }
    below_uniform = variance[y...(y + min_uniform_height)].to_a.all? { |v| v < variance_threshold }

    next unless above_uniform && below_uniform

    above_region = img_array[(y - min_uniform_height)...y, true, true]
    below_region = img_array[y...(y + min_uniform_height), true, true]

    above_color = calculate_mean_color(above_region)
    below_color = calculate_mean_color(below_region)

    # RGB 유클리드 거리
    color_diff = Math.sqrt(
      above_color.zip(below_color).map { |a, b| (a - b) ** 2 }.sum
    )

    transitions << y if color_diff > color_diff_threshold
  end

  merge_nearby_points(transitions)
end

#find_best_split_in_range(start_pos, end_pos, margin: 50) ⇒ Object

주어진 범위 내에서 복잡도가 가장 낮은 분할점 찾기



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# File 'lib/naiso/split_point_detector.rb', line 119

def find_best_split_in_range(start_pos, end_pos, margin: 50)
  search_start = start_pos + margin
  search_end = end_pos - margin

  return (start_pos + end_pos) / 2 if search_start >= search_end

  window_size = 20
  complexity = @analyzer.complexity

  region = complexity[search_start...search_end]
  return search_start + region.min_index if region.size < window_size

  # 이동 평균으로 smoothing
  smoothed = []
  (0...(region.size - window_size)).each do |i|
    smoothed << region[i...(i + window_size)].mean
  end

  best_idx = smoothed.each_with_index.min_by { |v, _| v }[1] + window_size / 2
  search_start + best_idx
end

#find_divider_lines(line_variance_threshold: 3.0, margin_check: 30, margin_variance_threshold: 5.0) ⇒ Object

가로 구분선 감지



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# File 'lib/naiso/split_point_detector.rb', line 48

def find_divider_lines(
  line_variance_threshold: 3.0,
  margin_check: 30,
  margin_variance_threshold: 5.0
)
  img_array = @analyzer.img_array
  variance = @analyzer.variance
  height = @analyzer.height

  dividers = []

  (margin_check...(height - margin_check)).each do |y|
    next if variance[y] > line_variance_threshold

    margin_above = img_array[(y - margin_check)...y, true, true]
    margin_below = img_array[(y + 1)...(y + 1 + margin_check), true, true]

    above_variance = calculate_region_variance(margin_above)
    below_variance = calculate_region_variance(margin_below)

    next if above_variance > margin_variance_threshold
    next if below_variance > margin_variance_threshold

    above_mean = margin_above.cast_to(Numo::DFloat).mean
    below_mean = margin_below.cast_to(Numo::DFloat).mean
    line_mean = img_array[y, true, true].cast_to(Numo::DFloat).mean

    color_diff = (line_mean - (above_mean + below_mean) / 2.0).abs
    dividers << y if color_diff > 10
  end

  merge_nearby_points(dividers)
end

#find_uniform_regions ⇒ Object

연속된 단색 영역 찾기



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# File 'lib/naiso/split_point_detector.rb', line 14

def find_uniform_regions
  variance = @analyzer.variance
  threshold = @config.variance_threshold

  regions = []
  in_region = false
  region_start = 0

  @analyzer.height.times do |i|
    uniform = variance[i] < threshold

    if uniform && !in_region
      in_region = true
      region_start = i
    elsif !uniform && in_region
      in_region = false
      if i - region_start >= @config.min_gap_height
        regions << [region_start, i]
      end
    end
  end

  # 마지막까지 단색이면
  if in_region
    region_end = @analyzer.height
    if region_end - region_start >= @config.min_gap_height
      regions << [region_start, region_end]
    end
  end

  regions
end