diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # phash
 
+## 0.1.3.0
+
+  * CLI tool now supports several more image formats
+  * `--debug` flag more useful
+  * `fileHash` now returns an `Either String`
+
 ## 0.1.2.0
 
   * Add `demo-data` field so tests don't fail
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -39,5 +39,5 @@
 [GHC](https://www.haskell.org/ghc/download.html). Then:
 
 ```
-cabal new-install perceptual-hash
+cabal install perceptual-hash -w ghc-8.6.5
 ```
diff --git a/app/Parallel.hs b/app/Parallel.hs
--- a/app/Parallel.hs
+++ b/app/Parallel.hs
@@ -1,7 +1,10 @@
+{-# LANGUAGE ScopedTypeVariables #-}
+
 module Parallel ( pathMaps ) where
 
 import           Control.Concurrent.STM      (atomically)
 import           Control.Concurrent.STM.TVar (TVar, modifyTVar', newTVarIO, readTVarIO)
+import           Data.Functor                (($>))
 import           Data.List.NonEmpty          (NonEmpty (..), (<|))
 import qualified Data.Map                    as M
 import           Data.Word                   (Word64)
@@ -13,15 +16,26 @@
 imgExtension ".jpg"  = True
 imgExtension ".jpeg" = True
 imgExtension ".png"  = True
-imgExtension _       = False -- gif doesn't work with CImg AFAICT
+imgExtension ".gif"  = True
+imgExtension ".hdr"  = True
+imgExtension ".pic"  = True
+imgExtension ".bmp"  = True
+imgExtension ".TGA"  = True
+imgExtension ".tga"  = True
+imgExtension ".tif"  = True
+imgExtension ".tiff" = True
+imgExtension _       = False
 
 insertHash :: FilePath -> IO (M.Map Word64 (NonEmpty FilePath) -> M.Map Word64 (NonEmpty FilePath))
 insertHash fp = do
     hash <- fileHash fp
-    pure $ \hashes ->
-        case M.lookup hash hashes of
-            Just others -> M.insert hash (fp <| others) hashes
-            Nothing     -> M.insert hash (fp :| []) hashes
+    case hash of
+        Right x ->
+            pure $ \hashes ->
+                case M.lookup x hashes of
+                    Just others -> M.insert x (fp <| others) hashes
+                    Nothing     -> M.insert x (fp :| []) hashes
+        Left err -> putStrLn ("WARNING: skipping " ++ fp ++ "\n" ++ err) $> id
 
 stepMap :: TVar (M.Map Word64 (NonEmpty FilePath)) -> FilePath -> IO ()
 stepMap var fp = do
diff --git a/bench/Bench.cpphs b/bench/Bench.cpphs
--- a/bench/Bench.cpphs
+++ b/bench/Bench.cpphs
@@ -1,14 +1,14 @@
 module Main (main) where
 
+import           Control.DeepSeq (NFData)
 import           Criterion.Main
-import           Data.Word       (Word64)
 #ifdef FOREIGN_PHASH
 import           ForeignHash     (foreignFileHash)
 #endif
 import           PerceptualHash  (fileHash)
 import           System.FilePath (takeFileName)
 
-mkBGroup :: String -> (FilePath -> IO Word64) -> Benchmark
+mkBGroup :: NFData a => String -> (FilePath -> IO a) -> Benchmark
 mkBGroup str f = bgroup str (toBench <$> [catPath, frogJpeg, frogPng])
 
     where toBench fp = bench (takeFileName fp) $ nfIO (f fp)
diff --git a/foreign-src/Export.hs b/foreign-src/Export.hs
new file mode 100644
--- /dev/null
+++ b/foreign-src/Export.hs
@@ -0,0 +1,14 @@
+module Export ()  where
+
+import           Control.Monad    ((<=<))
+import           Data.Word        (Word64)
+import           Foreign.C.String
+import           PerceptualHash
+
+-- | Hash an image at a given filepath
+hs_phash :: CString -> IO Word64
+hs_phash = fmap go . fileHash <=< peekCString
+    where go Left{}    = 0
+          go (Right x) = x
+
+foreign export ccall hs_phash :: CString -> IO Word64
diff --git a/perceptual-hash.cabal b/perceptual-hash.cabal
--- a/perceptual-hash.cabal
+++ b/perceptual-hash.cabal
@@ -1,6 +1,6 @@
 cabal-version:   2.0
 name:            perceptual-hash
-version:         0.1.2.0
+version:         0.1.3.0
 license:         BSD3
 license-file:    LICENSE
 copyright:       Copyright: (c) 2019 Vanessa McHale
@@ -65,6 +65,29 @@
     if impl(ghc >=8.4)
         ghc-options: -Wmissing-export-lists
 
+foreign-library hsphash
+    type:             native-shared
+    hs-source-dirs:   foreign-src
+    other-modules:    Export
+    default-language: Haskell2010
+    ghc-options:      -Wall
+    build-depends:
+        base -any,
+        perceptual-hash -any
+
+    lib-version-info: 1:0:0
+
+    if os(windows)
+        options: standalone
+
+    if impl(ghc >=8.0)
+        ghc-options:
+            -Wincomplete-uni-patterns -Wincomplete-record-updates
+            -Wredundant-constraints -Widentities
+
+    if impl(ghc >=8.4)
+        ghc-options: -Wmissing-export-lists
+
 executable phash
     main-is:          Main.hs
     hs-source-dirs:   app
@@ -75,6 +98,7 @@
 
     autogen-modules:  Paths_perceptual_hash
     default-language: Haskell2010
+    other-extensions: ScopedTypeVariables
     ghc-options:      -Wall -threaded -rtsopts "-with-rtsopts=-N -qg"
     build-depends:
         base >=4.9 && <5,
@@ -130,7 +154,8 @@
         base -any,
         perceptual-hash -any,
         criterion -any,
-        filepath -any
+        filepath -any,
+        deepseq -any
 
     if flag(llvm)
         ghc-options: -fllvm
diff --git a/src/PerceptualHash.hs b/src/PerceptualHash.hs
--- a/src/PerceptualHash.hs
+++ b/src/PerceptualHash.hs
@@ -11,7 +11,7 @@
 import           Data.Word                (Word64)
 import           Graphics.Image           (Array, Bilinear (..), Border (Edge, Reflect), Image,
                                            Pixel (PixelX, PixelY), RSU (..), X, Y, convolve, crop,
-                                           makeImage, readImageY, resize, transpose, (|*|))
+                                           makeImage, readImage, resize, transpose, (|*|))
 import           Graphics.Image.Interface (toVector)
 import qualified Graphics.Image.Interface as Hip
 import           Median                   (median)
@@ -61,5 +61,5 @@
     let med = medianImmut v
     in V.map (<med) v
 
-fileHash :: FilePath -> IO Word64
-fileHash = fmap imgHash . readImageY RSU
+fileHash :: FilePath -> IO (Either String Word64)
+fileHash = fmap (fmap (imgHash :: Image RSU Y Double -> Word64)) . readImage