Class: Map::Gdal::ConstrastStretchService

Inherits:
Object
  • Object
show all
Includes:
Base
Defined in:
lib/map/gdal/contrast_stretch_service.rb

Instance Attribute Summary collapse

Attributes included from Base

#files_to_clean

Instance Method Summary collapse

Methods included from Base

#add_to_clean, #clean, #gdal_running?, #get_file_name_with_path, #get_layer_name, #get_path_to_temp_file, #options_to_command_line, #run_command, #store_kml, #tmp_file

Constructor Details

#initialize(file) ⇒ ConstrastStretchService

Returns a new instance of ConstrastStretchService.



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# File 'lib/map/gdal/contrast_stretch_service.rb', line 7

def initialize(file)
  raise 'File does not exist' unless File.exist?(file)
  @file = file
end

Instance Attribute Details

#file ⇒ Object (readonly)

Returns the value of attribute file.



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# File 'lib/map/gdal/contrast_stretch_service.rb', line 6

def file
  @file
end

Instance Method Details

#call(options = {}) ⇒ Object 



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# File 'lib/map/gdal/contrast_stretch_service.rb', line 12

def call(options = {})
  file_out = get_path_to_temp_file(:gdal_contrast_stretch, :tif)
  add_to_clean(file_out)

  options['percentile-range'] = '0.02 0.98' if options.empty?

  result = run_command(%{gdal_contrast_stretch #{options_to_command_line(options)} "#{file}" "#{file_out}"})
  found_min_max = result.match(/src_range=\[(.+), (.+)\]/)
  {
    file: file_out,
    min: found_min_max[1].to_f,
    max: found_min_max[2].to_f,
  }
end