Read the EXIF File of a JPEG image with Haskell Code only.

This hexif library has similar functionality as the Hackage exif package. Hexif uses only pure Haskell code and no operating system library.

The first example shows how to print out all supported exif information of a JPEG image.

processFile :: FilePath -> IO()
processFile fn = do
    exif <- fromFile fn
    mapM_ putStrLn $ map format $ allFields exif
  where
    format (PrettyTitle t) = "\n" ++ t
    format (PrettyTag t v) = "  " ++ t ++ " -> " ++ v
-- Example: processFile "RS4748.JPG"

The next example prints out the value of a single tag:

singleTag :: FilePath -> ExifTag -> IO()
singleTag fn tag = do
    exif <- fromFile fn
    print $ getTag exif tag
-- Example: singleTag "RS4847.JPG" TagComponentsConfiguration

The supported exit tags are listed in the module Graphics.Hexif.DataExif.

Sample output of first example:

0th IFD
  ImageDescription -> SONY DSC
  Model -> DSLR-A200
  Make -> SONY
  XResolution -> 72
  YResolution -> 72
  ResolutionUnit -> Inch
  Software -> DSLR-A200 v1.00
  DateTime -> 2012:08:12 13:14:44
  Artist -> Picasa
  YCbCrPositioning -> Co-sited
  PrintImageMatching -> 124 bytes undefined data

Exif IFD
  ExposureTime -> 1/200 sec.
  FNumber -> f/10.0
  ExposureProgram -> Landscape mode (for landscape photos with the background in focus)
  ISOSpeedRatings -> 100
  ExifVersion -> Exif Version 2.21
  DateTimeOriginal -> 2012:08:10 13:08:57
  DateTimeDigitized -> 2012:08:10 13:08:57
  ComponentsConfiguration -> Y Cb Cr -
  CompressedBitsPerPixel ->  8
  BrightnessValue -> 9.37 EV (2267.10 cd/m^2)
  ExposureBiasValue -> 0.00 EV
  MaxApertureValue -> 3.61 EV (f/3.5)
  MeteringMode -> Pattern
  LightSource -> Unknown
  Flash -> Flash did not fire, compulsory flash mode
  FocalLength -> 18.0 mm
  MakerNote -> 4890 bytes undefined data
  UserComment -> 64 bytes undefined data
  FlashPixVersion -> FlashPix Version 1.0
  ColorSpace -> sRGB
  PixelXDimension -> 3872
  PixelYDimension -> 2592
  FileSource -> DSC
  SceneType -> Directly photographed
  CustomRendered -> Normal process
  ExposureMode -> Auto exposure
  WhiteBalance -> Auto white balance
  FocalLengthIn35mmFilm -> 27
  SceneCaptureType -> Landscape
  Contrast -> Normal
  Saturation -> Normal
  Sharpness -> Normal
  ImageUniqueID -> 377d19784e8ea1d75c0554aa09d7dad5

GPS IFD
  GPSVersionID -> 2.0.0.0
  GPSLatitudeRef -> N
  GPSLatitude -> 46, 28, 0.2900
  GPSLongitudeRef -> E
  GPSLongitude ->  8,  9, 59.9800
  GPSAltitudeRef -> Sea level
  GPSAltitude -> 2793.9912
  GPSTimeStamp -> 11:08:57.00
  GPSMapDatum -> WGS-84
  GPSDateStamp -> 2012:08:10

Interop IFD
  InteroperabilityIndex -> R98
  InteroperabilityVersion -> 0100
  RelatedImageWidth -> 3872
  RelatedImageLength -> 2592

1 st IFD (Thumbnail)
  Compression -> JPEG compression
  XResolution -> 72
  YResolution -> 72
  ResolutionUnit -> Inch
  JPEGInterchangeFormat -> 6252
  JPEGInterchangeFormatLength -> 5922

Similar libraries

The hsexif is a similar library. If in doubt, use hsexif!

Pros of hexif

• hexif can show you all tags in an JPEG file including tags unknown to the program. hsexif has also a function called allExifTags, however, this prints just a predefined list of tags.

Pros of hsexif

• hsexif is on Hackage
• hsexif has more typed functions to access the Exif values
• hsexif supports more files created by different camera brands