Module: KvgCharacterRecognition::Trainer

Included in:
Recognizer, Template
Defined in:
lib/kvg_character_recognition/trainer.rb

Constant Summary collapse

@@config = 
{ downsample_rate: 4,
             interpolate_distance: 0.8,
             size: 109,
             smooth: true,
             smooth_weights: [1,2,3,2,1],
             smooth_filter_weights: [1/9.0, 1/9.0, 1/9.0, 1/9.0, 1/9.0, 1/9.0, 1/9.0, 1/9.0, 1/9.0],
             heatmap_number_of_grids: 17
}
@@preprocessor = 
Preprocessor.new(@@config[:interpolate_distance],
@@config[:size],
@@config[:smooth],
@@config[:smooth_weights])

Instance Method Summary collapse

Instance Method Details

#heatmaps(strokes) ⇒ Object

This method returns the 3x 17x17 direction feature vector strokes are preprocessed



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# File 'lib/kvg_character_recognition/trainer.rb', line 29

def heatmaps strokes
  weights = @@config[:smooth_filter_weights]
  number_of_grids = @@config[:heatmap_number_of_grids]

  bi_normed = strokes
  ld_normed = @@preprocessor.line_density_normalize(bi_normed).map{ |stroke| downsample(stroke, @@config[:downsample_rate]) }
  pd_normed = @@preprocessor.point_density_normalize(bi_normed).map{ |stroke| downsample(stroke, @@config[:downsample_rate]) }
  bi_normed = bi_normed.map{ |stroke| downsample(stroke, @@config[:downsample_rate]) }

  # feature extraction
  heatmaps_map = HeatmapFeature.new(bi_normed,
                                    ld_normed,
                                    pd_normed,
                                    @@config[:size],
                                    number_of_grids,
                                    weights).heatmaps

  # convert to feature vector
  Matrix.columns(heatmaps_map.to_a).to_a
end

#preprocess(strokes) ⇒ Object

preprocess strokes and set the number_of_points variable !the preprocessed strokes are not downsampled



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# File 'lib/kvg_character_recognition/trainer.rb', line 21

def preprocess strokes
  strokes = @@preprocessor.preprocess(strokes)
  @number_of_points = strokes.flatten(1).count
  strokes
end