Module: DHashVips::DHash

Extended by:
DHash
Included in:
DHash
Defined in:
lib/dhash-vips.rb

Instance Method Summary collapse

Instance Method Details

#calculate(file, hash_size = 8) ⇒ Object 



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# File 'lib/dhash-vips.rb', line 25

def calculate file, hash_size = 8
  image = pixelate file, hash_size
  image.cast("int").conv([[1, -1]]).crop(1, 0, hash_size, hash_size).>(0)./(255).cast("uchar").to_a.join.to_i(2)
end

#hamming(a, b) ⇒ Object 



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# File 'lib/dhash-vips.rb', line 13

def hamming a, b
  (a ^ b).to_s(2).count "1"
end

#pixelate(input, hash_size) ⇒ Object 



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# File 'lib/dhash-vips.rb', line 17

def pixelate input, hash_size
  ::DHashVips.bw( if input.is_a? ::Vips::Image
    input.thumbnail_image(hash_size + 1, height: hash_size, size: :force)
  else
    ::Vips::Image.thumbnail(input, hash_size + 1, height: hash_size, size: :force)
  end )
end