diff options
Diffstat (limited to 'src/Text/Pandoc/ImageSize.hs')
| -rw-r--r-- | src/Text/Pandoc/ImageSize.hs | 267 |
1 files changed, 258 insertions, 9 deletions
diff --git a/src/Text/Pandoc/ImageSize.hs b/src/Text/Pandoc/ImageSize.hs index 273a1a428..68b34dcf3 100644 --- a/src/Text/Pandoc/ImageSize.hs +++ b/src/Text/Pandoc/ImageSize.hs @@ -1,6 +1,6 @@ {-# LANGUAGE OverloadedStrings, ScopedTypeVariables #-} {- - Copyright (C) 2011 John MacFarlane <jgm@berkeley.edu> + Copyright (C) 2011-2014 John MacFarlane <jgm@berkeley.edu> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -19,7 +19,7 @@ {- | Module : Text.Pandoc.ImageSize -Copyright : Copyright (C) 2011 John MacFarlane +Copyright : Copyright (C) 2011-2014 John MacFarlane License : GNU GPL, version 2 or above Maintainer : John MacFarlane <jgm@berkeley.edu> @@ -32,13 +32,19 @@ module Text.Pandoc.ImageSize ( ImageType(..), imageType, imageSize, sizeInPixels, sizeInPoints ) where import Data.ByteString (ByteString, unpack) import qualified Data.ByteString.Char8 as B +import qualified Data.ByteString.Lazy as BL +import Control.Applicative import Control.Monad import Data.Bits +import Data.Binary +import Data.Binary.Get +import Text.Pandoc.Shared (safeRead) +import qualified Data.Map as M -- quick and dirty functions to get image sizes -- algorithms borrowed from wwwis.pl -data ImageType = Png | Gif | Jpeg | Pdf deriving Show +data ImageType = Png | Gif | Jpeg | Pdf | Eps deriving Show data ImageSize = ImageSize{ pxX :: Integer @@ -52,8 +58,12 @@ imageType :: ByteString -> Maybe ImageType imageType img = case B.take 4 img of "\x89\x50\x4e\x47" -> return Png "\x47\x49\x46\x38" -> return Gif - "\xff\xd8\xff\xe0" -> return Jpeg + "\xff\xd8\xff\xe0" -> return Jpeg -- JFIF + "\xff\xd8\xff\xe1" -> return Jpeg -- Exif "%PDF" -> return Pdf + "%!PS" + | (B.take 4 $ B.drop 1 $ B.dropWhile (/=' ') img) == "EPSF" + -> return Eps _ -> fail "Unknown image type" imageSize :: ByteString -> Maybe ImageSize @@ -63,14 +73,35 @@ imageSize img = do Png -> pngSize img Gif -> gifSize img Jpeg -> jpegSize img + Eps -> epsSize img Pdf -> Nothing -- TODO +defaultSize :: (Integer, Integer) +defaultSize = (72, 72) + sizeInPixels :: ImageSize -> (Integer, Integer) sizeInPixels s = (pxX s, pxY s) sizeInPoints :: ImageSize -> (Integer, Integer) sizeInPoints s = (pxX s * 72 `div` dpiX s, pxY s * 72 `div` dpiY s) +epsSize :: ByteString -> Maybe ImageSize +epsSize img = do + let ls = takeWhile ("%" `B.isPrefixOf`) $ B.lines img + let ls' = dropWhile (not . ("%%BoundingBox:" `B.isPrefixOf`)) ls + case ls' of + [] -> mzero + (x:_) -> case B.words x of + (_:_:_:ux:uy:[]) -> do + ux' <- safeRead $ B.unpack ux + uy' <- safeRead $ B.unpack uy + return ImageSize{ + pxX = ux' + , pxY = uy' + , dpiX = 72 + , dpiY = 72 } + _ -> mzero + pngSize :: ByteString -> Maybe ImageSize pngSize img = do let (h, rest) = B.splitAt 8 img @@ -117,8 +148,14 @@ gifSize img = do jpegSize :: ByteString -> Maybe ImageSize jpegSize img = do let (hdr, rest) = B.splitAt 4 img - guard $ hdr == "\xff\xd8\xff\xe0" guard $ B.length rest >= 14 + case hdr of + "\xff\xd8\xff\xe0" -> jfifSize rest + "\xff\xd8\xff\xe1" -> exifSize $ B.takeWhile (/= '\xff') rest + _ -> mzero + +jfifSize :: ByteString -> Maybe ImageSize +jfifSize rest = do let [dpiDensity,dpix1,dpix2,dpiy1,dpiy2] = map fromIntegral $ unpack $ B.take 5 $ B.drop 9 $ rest let factor = case dpiDensity of @@ -127,11 +164,11 @@ jpegSize img = do _ -> const 72 let dpix = factor (shift dpix1 8 + dpix2) let dpiy = factor (shift dpiy1 8 + dpiy2) - (w,h) <- findJpegSize rest + (w,h) <- findJfifSize rest return $ ImageSize { pxX = w, pxY = h, dpiX = dpix, dpiY = dpiy } -findJpegSize :: ByteString -> Maybe (Integer,Integer) -findJpegSize bs = do +findJfifSize :: ByteString -> Maybe (Integer,Integer) +findJfifSize bs = do let bs' = B.dropWhile (=='\xff') $ B.dropWhile (/='\xff') bs case B.uncons bs' of Just (c,bs'') | c >= '\xc0' && c <= '\xc3' -> do @@ -143,8 +180,220 @@ findJpegSize bs = do [c1,c2] -> do let len = shift c1 8 + c2 -- skip variables - findJpegSize $ B.drop len bs'' + findJfifSize $ B.drop len bs'' _ -> fail "JPEG parse error" Nothing -> fail "Did not find length record" +exifSize :: ByteString -> Maybe ImageSize +exifSize bs = runGet (Just <$> exifHeader bl) bl + where bl = BL.fromChunks [bs] +-- NOTE: It would be nicer to do +-- runGet ((Just <$> exifHeader) <|> return Nothing) +-- which would prevent pandoc from raising an error when an exif header can't +-- be parsed. But we only get an Alternative instance for Get in binary 0.6, +-- and binary 0.5 ships with ghc 7.6. + +exifHeader :: BL.ByteString -> Get ImageSize +exifHeader hdr = do + _app1DataSize <- getWord16be + exifHdr <- getWord32be + unless (exifHdr == 0x45786966) $ fail "Did not find exif header" + zeros <- getWord16be + unless (zeros == 0) $ fail "Expected zeros after exif header" + -- beginning of tiff header -- we read whole thing to use + -- in getting data from offsets: + let tiffHeader = BL.drop 8 hdr + byteAlign <- getWord16be + let bigEndian = byteAlign == 0x4d4d + let (getWord16, getWord32, getWord64) = + if bigEndian + then (getWord16be, getWord32be, getWord64be) + else (getWord16le, getWord32le, getWord64le) + let getRational = do + num <- getWord32 + den <- getWord32 + return $ fromIntegral num / fromIntegral den + tagmark <- getWord16 + unless (tagmark == 0x002a) $ fail "Failed alignment sanity check" + ifdOffset <- getWord32 + skip (fromIntegral ifdOffset - 8) -- skip to IDF + numentries <- getWord16 + let ifdEntry = do + tag <- getWord16 >>= \t -> + maybe (return UnknownTagType) return + (M.lookup t tagTypeTable) + dataFormat <- getWord16 + numComponents <- getWord32 + (fmt, bytesPerComponent) <- + case dataFormat of + 1 -> return (UnsignedByte . runGet getWord8, 1) + 2 -> return (AsciiString, 1) + 3 -> return (UnsignedShort . runGet getWord16, 2) + 4 -> return (UnsignedLong . runGet getWord32, 4) + 5 -> return (UnsignedRational . runGet getRational, 8) + 6 -> return (SignedByte . runGet getWord8, 1) + 7 -> return (Undefined . runGet getWord8, 1) + 8 -> return (SignedShort . runGet getWord16, 2) + 9 -> return (SignedLong . runGet getWord32, 4) + 10 -> return (SignedRational . runGet getRational, 8) + 11 -> return (SingleFloat . runGet getWord32 {- TODO -}, 4) + 12 -> return (DoubleFloat . runGet getWord64 {- TODO -}, 8) + _ -> fail $ "Unknown data format " ++ show dataFormat + let totalBytes = fromIntegral $ numComponents * bytesPerComponent + payload <- if totalBytes <= 4 -- data is right here + then fmt <$> + (getLazyByteString (fromIntegral totalBytes) <* + skip (4 - totalBytes)) + else do -- get data from offset + offs <- getWord32 + return $ fmt $ BL.take (fromIntegral totalBytes) $ + BL.drop (fromIntegral offs) tiffHeader + return (tag, payload) + entries <- sequence $ replicate (fromIntegral numentries) ifdEntry + subentries <- case lookup ExifOffset entries of + Just (UnsignedLong offset) -> do + pos <- bytesRead + skip (fromIntegral offset - (fromIntegral pos - 8)) + numsubentries <- getWord16 + sequence $ + replicate (fromIntegral numsubentries) ifdEntry + _ -> return [] + let allentries = entries ++ subentries + (width, height) <- case (lookup ExifImageWidth allentries, + lookup ExifImageHeight allentries) of + (Just (UnsignedLong w), Just (UnsignedLong h)) -> + return (fromIntegral w, fromIntegral h) + _ -> return defaultSize + -- we return a default width and height when + -- the exif header doesn't contain these + let resfactor = case lookup ResolutionUnit allentries of + Just (UnsignedShort 1) -> (100 / 254) + _ -> 1 + let xres = maybe 72 (\(UnsignedRational x) -> floor $ x * resfactor) + $ lookup XResolution allentries + let yres = maybe 72 (\(UnsignedRational x) -> floor $ x * resfactor) + $ lookup YResolution allentries + return $ ImageSize{ + pxX = width + , pxY = height + , dpiX = xres + , dpiY = yres } + +data DataFormat = UnsignedByte Word8 + | AsciiString BL.ByteString + | UnsignedShort Word16 + | UnsignedLong Word32 + | UnsignedRational Rational + | SignedByte Word8 + | Undefined Word8 + | SignedShort Word16 + | SignedLong Word32 + | SignedRational Rational + | SingleFloat Word32 + | DoubleFloat Word64 + deriving (Show) + +data TagType = ImageDescription + | Make + | Model + | Orientation + | XResolution + | YResolution + | ResolutionUnit + | Software + | DateTime + | WhitePoint + | PrimaryChromaticities + | YCbCrCoefficients + | YCbCrPositioning + | ReferenceBlackWhite + | Copyright + | ExifOffset + | ExposureTime + | FNumber + | ExposureProgram + | ISOSpeedRatings + | ExifVersion + | DateTimeOriginal + | DateTimeDigitized + | ComponentConfiguration + | CompressedBitsPerPixel + | ShutterSpeedValue + | ApertureValue + | BrightnessValue + | ExposureBiasValue + | MaxApertureValue + | SubjectDistance + | MeteringMode + | LightSource + | Flash + | FocalLength + | MakerNote + | UserComment + | FlashPixVersion + | ColorSpace + | ExifImageWidth + | ExifImageHeight + | RelatedSoundFile + | ExifInteroperabilityOffset + | FocalPlaneXResolution + | FocalPlaneYResolution + | FocalPlaneResolutionUnit + | SensingMethod + | FileSource + | SceneType + | UnknownTagType + deriving (Show, Eq, Ord) +tagTypeTable :: M.Map Word16 TagType +tagTypeTable = M.fromList + [ (0x010e, ImageDescription) + , (0x010f, Make) + , (0x0110, Model) + , (0x0112, Orientation) + , (0x011a, XResolution) + , (0x011b, YResolution) + , (0x0128, ResolutionUnit) + , (0x0131, Software) + , (0x0132, DateTime) + , (0x013e, WhitePoint) + , (0x013f, PrimaryChromaticities) + , (0x0211, YCbCrCoefficients) + , (0x0213, YCbCrPositioning) + , (0x0214, ReferenceBlackWhite) + , (0x8298, Copyright) + , (0x8769, ExifOffset) + , (0x829a, ExposureTime) + , (0x829d, FNumber) + , (0x8822, ExposureProgram) + , (0x8827, ISOSpeedRatings) + , (0x9000, ExifVersion) + , (0x9003, DateTimeOriginal) + , (0x9004, DateTimeDigitized) + , (0x9101, ComponentConfiguration) + , (0x9102, CompressedBitsPerPixel) + , (0x9201, ShutterSpeedValue) + , (0x9202, ApertureValue) + , (0x9203, BrightnessValue) + , (0x9204, ExposureBiasValue) + , (0x9205, MaxApertureValue) + , (0x9206, SubjectDistance) + , (0x9207, MeteringMode) + , (0x9208, LightSource) + , (0x9209, Flash) + , (0x920a, FocalLength) + , (0x927c, MakerNote) + , (0x9286, UserComment) + , (0xa000, FlashPixVersion) + , (0xa001, ColorSpace) + , (0xa002, ExifImageWidth) + , (0xa003, ExifImageHeight) + , (0xa004, RelatedSoundFile) + , (0xa005, ExifInteroperabilityOffset) + , (0xa20e, FocalPlaneXResolution) + , (0xa20f, FocalPlaneYResolution) + , (0xa210, FocalPlaneResolutionUnit) + , (0xa217, SensingMethod) + , (0xa300, FileSource) + , (0xa301, SceneType) + ] |