module Data.PHash ( hammingDistance
, imagesSimilar
, module Data.PHash.Image
, module Data.PHash.Types ) where
import Control.Applicative ( (<$>)
, (<*>) )
import Foreign.C.Types
import Data.PHash.Image
import Data.PHash.Types
hammingDistance :: PHash -> PHash -> Int
hammingDistance x y = unwrap $ c_ph_hamming_distance (toCPHash x) (toCPHash y)
where unwrap (CInt i) = fromIntegral i
imagesSimilar :: FilePath
-> FilePath
-> Int
-> IO (Maybe Bool)
imagesSimilar p1 p2 threshold = do
h1 <- imageHash p1
h2 <- imageHash p2
return $ checkDistance <$> h1 <*> h2
where checkDistance h1 h2 = (<=threshold) $ hammingDistance h1 h2
foreign import ccall "pHash.h ph_hamming_distance" c_ph_hamming_distance :: CULong -> CULong -> CInt