Module: Vips::Process::AutoOrient

Defined in:
lib/vips-process/auto-orient.rb

Constant Summary collapse

EMPTY_STRING = 
''.freeze
EXIF_ORIENTATION = 
'exif-Orientation'.freeze
EXIF_IFD0_ORIENTATION = 
'exif-ifd0-Orientation'.freeze

Instance Method Summary collapse

Instance Method Details

#auto_orient ⇒ Object

Read the camera EXIF data to determine orientation and adjust accordingly



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# File 'lib/vips-process/auto-orient.rb', line 9

def auto_orient
  manipulate! do |image|
    o   = image.get(EXIF_ORIENTATION).to_i      rescue nil
    o ||= image.get(EXIF_IFD0_ORIENTATION).to_i rescue 1

    case o
    when 1
      # Do nothing, everything is peachy
    when 6
      image.rot270
    when 8
      image.rot180
    when 3
      image.rot90
    else
      raise('Invalid value for Orientation: ' + o.to_s)
    end
    image.set EXIF_ORIENTATION, EMPTY_STRING
    image.set EXIF_IFD0_ORIENTATION, EMPTY_STRING
  end
  self
end