-- | -- Module : Data.Array.Accelerate.IO.BMP -- Copyright : [2012..2014] Trevor L. McDonell -- License : BSD3 -- -- Maintainer : Trevor L. McDonell <tmcdonell@cse.unsw.edu.au> -- Stability : experimental -- Portability : non-portable (GHC extensions) -- -- Read and write BMP images into a packed-word RGBA format. See the -- /colour-accelerate/ package for colour representations and utilities such as -- packing and unpacking. -- module Data.Array.Accelerate.IO.BMP ( -- ** Bitmap images -- -- | Reading and writing arrays as uncompressed 24 or 32-bit Windows BMP -- files. -- RGBA32, readImageFromBMP, writeImageToBMP, ) where import Data.Word import Codec.BMP import Data.Array.Accelerate as A import Data.Array.Accelerate.IO.ByteString as A -- | Packed RGBA pixel data -- type RGBA32 = Word32 -- File IO --------------------------------------------------------------------- -- | Read RGBA components from a BMP file. -- readImageFromBMP :: FilePath -> IO (Either Error (Array DIM2 RGBA32)) readImageFromBMP file = do ebmp <- readBMP file case ebmp of Left err -> return $ Left err Right bmp -> do let (w,h) = bmpDimensions bmp bs = unpackBMPToRGBA32 bmp -- Right `fmap` A.fromByteString (Z :. h :. w) bs -- | Write the image data to a file. -- writeImageToBMP :: FilePath -> Array DIM2 RGBA32 -> IO () writeImageToBMP file rgba = do let Z :. h :. w = A.arrayShape rgba bs <- A.toByteString rgba -- writeBMP file (packRGBA32ToBMP w h bs)