diff --git a/png-file.cabal b/png-file.cabal
--- a/png-file.cabal
+++ b/png-file.cabal
@@ -2,7 +2,7 @@
 cabal-version:	>= 1.8
 
 name:		png-file
-version:	0.0.1.0
+version:	0.0.1.1
 stability:	Experimental
 author:		Yoshikuni Jujo <PAF01143@nifty.ne.jp>
 maintainer:	Yoshikuni Jujo <PAF01143@nifty.ne.jp>
@@ -24,7 +24,7 @@
 source-repository	this
     type:	git
     location:	git://github.com/YoshikuniJujo/png-file.git
-    tag:	0.0.1.0
+    tag:	0.0.1.1
 
 library
     hs-source-dirs:	src
@@ -34,6 +34,7 @@
         File.Binary.PNG.Chunks,
         File.Binary.PNG.Chunks.CRC,
         File.Binary.PNG.Chunks.Each,
+        File.Binary.PNG.DataChunks
         Language.Haskell.TH.Tools
     build-depends:
         base > 3 && < 5, binary-file, bytestring, zlib, array,
diff --git a/src/File/Binary/PNG/DataChunks.hs b/src/File/Binary/PNG/DataChunks.hs
new file mode 100644
--- /dev/null
+++ b/src/File/Binary/PNG/DataChunks.hs
@@ -0,0 +1,82 @@
+module File.Binary.PNG.DataChunks (
+	module File.Binary.PNG.Chunks,
+	makePNGHeader,
+	bsToPNGImage,
+	pngImageToBS,
+	PNGImageL(..),
+	PNGImageLColor(..),
+	readIccp
+) where
+
+import File.Binary.PNG.Data
+import File.Binary.PNG.Chunks
+import Data.Bits
+import qualified Data.ByteString.Lazy as BSL
+import Data.List
+
+bsToPNGImage :: PNGImage pi =>
+	IHDR -> Maybe PLTE -> Maybe TRNS -> BSL.ByteString -> Either String pi
+bsToPNGImage ihdr plte trns bs = do
+	h <- makePNGHeader ihdr plte trns
+	return $ makePNGImage h bs
+
+pngImageToBS :: PNGImage pi => pi -> (IHDR, Maybe TRNS, BSL.ByteString)
+pngImageToBS pi = let
+	(header, bs) = fromPNGImage pi
+	(ihdr, trns) = fromPNGHeader header in
+	(ihdr, trns, bs)
+
+makePNGHeader :: IHDR -> Maybe PLTE -> Maybe TRNS -> Either String PNGHeader
+makePNGHeader ihdr plte trns = do
+	ct <- getColorType (alpha ihdr) (color ihdr) (palet ihdr) trns
+	return PNGHeader {
+		pngWidth = width ihdr,
+		pngHeight = height ihdr,
+		pngDepth = depth ihdr,
+		pngColorType = ct,
+		pngCompType = compressionType ihdr,
+		pngFilterType = filterType ihdr,
+		pngInterlaceType = interlaceType ihdr,
+		pngPalette = maybe [] plteToInts plte
+	 }
+
+plteToInts :: PLTE -> [(Int, Int, Int)]
+plteToInts = map (\(RGB8 r g b) -> (fi r, fi g, fi b)) . colors
+	where
+	fi = fromIntegral
+
+fromPNGHeader :: PNGHeader -> (IHDR, Maybe TRNS)
+fromPNGHeader ph@PNGHeader { pngColorType = PNGTypeColor Nothing } = (IHDR {
+	width = pngWidth ph,
+	height = pngHeight ph,
+	depth = pngDepth ph,
+	alpha = False,
+	color = True,
+	palet = False,
+	compressionType = 0,
+	filterType = 0,
+	interlaceType = 0 }, Nothing)
+getTRNSChunk :: [Chunk] -> Maybe Chunk
+getTRNSChunk = find ((== T_tRNS) . typeChunk)
+
+getColorType :: Bool -> Bool -> Bool -> Maybe TRNS -> Either String PNGColorType
+getColorType False True True = return . PNGTypeIndex . maybe [] readTRNSi
+getColorType False False False = return . PNGTypeGrey . fmap readTRNSg
+getColorType False True False = return . PNGTypeColor . fmap readTRNSc
+getColorType True False False = const $ return PNGTypeGreyAlpha
+getColorType True True False = const $ return PNGTypeColorAlpha
+getColorType _ _ _ = fail "bad colortype"
+
+readTRNSi :: TRNS -> [Int]
+readTRNSi = map fromIntegral . BSL.unpack . dat
+
+readTRNSg :: TRNS -> Int
+readTRNSg t = let [h, l] = map fromIntegral $ BSL.unpack $ dat t in
+	h `shiftL` 8 .|. l
+
+readTRNSc :: TRNS -> (Int, Int, Int)
+readTRNSc t = let
+	[rh, rl, gh, gl, bh, bl] = map fromIntegral $ BSL.unpack $ dat t in (
+		rh `shiftL` 8 .|. rl,
+		gh `shiftL` 8 .|. gl,
+		bh `shiftL` 8 .|. bl)