Codec.Picture.Metadata

JuicyPixels-3.3.8: Picture loading/serialization (in png, jpeg, bitmap, gif, tga, tiff and radiance)

Safe Haskell | None
Language | Haskell2010

Codec.Picture.Metadata

Contents

- Types
- Functions
- Folding
- Helper functions
- Conversion functions

Description

This module expose a common "metadata" storage for various image type. Different format can generate different metadatas, and write only a part of them.

Since version 3.2.5

Synopsis

- data Metadatas
- data Keys a where
  - Gamma :: Keys Double
  - ColorSpace :: Keys ColorSpace
  - Format :: Keys SourceFormat
  - DpiX :: Keys Word
  - DpiY :: Keys Word
  - Width :: Keys Word
  - Height :: Keys Word
  - Title :: Keys [Char]
  - Description :: Keys [Char]
  - Author :: Keys [Char]
  - Copyright :: Keys [Char]
  - Software :: Keys [Char]
  - Comment :: Keys [Char]
  - Disclaimer :: Keys [Char]
  - Source :: Keys [Char]
  - Warning :: Keys [Char]
  - Exif :: !ExifTag -> Keys ExifData
  - Unknown :: !String -> Keys Value
- data Value
  - = Int !Int
  - | Double !Double
  - | String !String
- data Elem (k :: Type -> Type) = (Show a, NFData a) => !(k a) :=> a
- data SourceFormat
  - = SourceJpeg
  - | SourceGif
  - | SourceBitmap
  - | SourceTiff
  - | SourcePng
  - | SourceHDR
  - | SourceTGA
- data ColorSpace
  - = SRGB
  - | WindowsBitmapColorSpace !ByteString
  - | ICCProfile !ByteString
- lookup :: Keys a -> Metadatas -> Maybe a
- empty :: Metadatas
- insert :: (Show a, NFData a) => Keys a -> a -> Metadatas -> Metadatas
- delete :: Keys a -> Metadatas -> Metadatas
- singleton :: (Show a, NFData a) => Keys a -> a -> Metadatas
- foldl' :: (acc -> Elem Keys -> acc) -> acc -> Metadatas -> acc
- foldMap :: Monoid m => (Elem Keys -> m) -> Metadatas -> m
- mkDpiMetadata :: Word -> Metadatas
- mkSizeMetadata :: Integral n => n -> n -> Metadatas
- basicMetadata :: Integral nSize => SourceFormat -> nSize -> nSize -> Metadatas
- simpleMetadata :: (Integral nSize, Integral nDpi) => SourceFormat -> nSize -> nSize -> nDpi -> nDpi -> Metadatas
- extractExifMetas :: Metadatas -> [(ExifTag, ExifData)]
- dotsPerMeterToDotPerInch :: Word -> Word
- dotPerInchToDotsPerMeter :: Word -> Word
- dotsPerCentiMeterToDotPerInch :: Word -> Word

# Types

data Metadatas #

Dependent storage used for metadatas. All metadatas of a given kind are unique within this container.

The current data structure is based on list, so bad performances can be expected.

#### Instances

Instances details

Monoid Metadatas # |
Instance details Defined in Codec.Picture.Metadata Methods mempty :: Metadatas # mappend :: Metadatas -> Metadatas -> Metadatas # mconcat :: [Metadatas] -> Metadatas #
Semigroup Metadatas # |
Instance details Defined in Codec.Picture.Metadata Methods (<>) :: Metadatas -> Metadatas -> Metadatas # sconcat :: NonEmpty Metadatas -> Metadatas # stimes :: Integral b => b -> Metadatas -> Metadatas #
Show Metadatas # |
Instance details Defined in Codec.Picture.Metadata Methods showsPrec :: Int -> Metadatas -> ShowS # show :: Metadatas -> String # showList :: [Metadatas] -> ShowS #
NFData Metadatas # |
Instance details Defined in Codec.Picture.Metadata Methods rnf :: Metadatas -> () #

data Keys a where #

Store various additional information about an image. If something is not recognized, it can be stored in an unknown tag.

- `DpiX` Dot per inch on this x axis.
- `DpiY` Dot per inch on this y axis.
- `Width` Image width in pixel. Relying on the metadata for this information can avoid the full decompression of the image. Ignored for image writing.
- `Height` Image height in pixels. Relying on the metadata for this information can void the full decompression of the image. Ignored for image writing.
- `ColorProfile` An unparsed ICC color profile. Currently only supported by the Bitmap format.
- `Unknown` unlikely to be decoded, but usefull for metadata writing
- `Exif` Exif tag and associated data.

Constructors

Gamma :: Keys Double |
ColorSpace :: Keys ColorSpace |
Format :: Keys SourceFormat |
DpiX :: Keys Word |
DpiY :: Keys Word |
Width :: Keys Word |
Height :: Keys Word |
Title :: Keys [Char] |
Description :: Keys [Char] |
Author :: Keys [Char] |
Copyright :: Keys [Char] |
Software :: Keys [Char] |
Comment :: Keys [Char] |
Disclaimer :: Keys [Char] |
Source :: Keys [Char] |
Warning :: Keys [Char] |
Exif :: !ExifTag -> Keys ExifData |
Unknown :: !String -> Keys Value |

#### Instances

Instances details

Show (Elem Keys) # |
Instance details Defined in Codec.Picture.Metadata Methods showsPrec :: Int -> Elem Keys -> ShowS # show :: Elem Keys -> String # showList :: [Elem Keys] -> ShowS #
Show (Keys a) # |
Instance details Defined in Codec.Picture.Metadata Methods showsPrec :: Int -> Keys a -> ShowS # show :: Keys a -> String # showList :: [Keys a] -> ShowS #
NFData (Elem Keys) # |
Instance details Defined in Codec.Picture.Metadata Methods rnf :: Elem Keys -> () #
Eq (Keys a) # |
Instance details Defined in Codec.Picture.Metadata Methods (==) :: Keys a -> Keys a -> Bool # (/=) :: Keys a -> Keys a -> Bool #

data Value #

Encode values for unknown information

Constructors

Int !Int |
Double !Double |
String !String |

#### Instances

Instances details

Show Value # |
Instance details Defined in Codec.Picture.Metadata Methods showsPrec :: Int -> Value -> ShowS # show :: Value -> String # showList :: [Value] -> ShowS #
NFData Value # |
Instance details Defined in Codec.Picture.Metadata Methods rnf :: Value -> () #
Eq Value # |
Instance details Defined in Codec.Picture.Metadata Methods (==) :: Value -> Value -> Bool # (/=) :: Value -> Value -> Bool #

data Elem (k :: Type -> Type) #

Element describing a metadata and it's (typed) associated value.

Constructors

(Show a, NFData a) => !(k a) :=> a |

#### Instances

Instances details

Show (Elem Keys) # |
Instance details Defined in Codec.Picture.Metadata Methods showsPrec :: Int -> Elem Keys -> ShowS # show :: Elem Keys -> String # showList :: [Elem Keys] -> ShowS #
NFData (Elem Keys) # |
Instance details Defined in Codec.Picture.Metadata Methods rnf :: Elem Keys -> () #

data SourceFormat #

Type describing the original file format of the file.

Constructors

SourceJpeg |
SourceGif |
SourceBitmap |
SourceTiff |
SourcePng |
SourceHDR |
SourceTGA |

#### Instances

Instances details

Show SourceFormat # |
Instance details Defined in Codec.Picture.Metadata Methods showsPrec :: Int -> SourceFormat -> ShowS # show :: SourceFormat -> String # showList :: [SourceFormat] -> ShowS #
NFData SourceFormat # |
Instance details Defined in Codec.Picture.Metadata Methods rnf :: SourceFormat -> () #
Eq SourceFormat # |
Instance details Defined in Codec.Picture.Metadata Methods (==) :: SourceFormat -> SourceFormat -> Bool # (/=) :: SourceFormat -> SourceFormat -> Bool #

data ColorSpace #

The same color values may result in slightly different colors on different devices. To get consistent colors accross multiple devices we need a way of mapping color values from a source device into their equivalents on the target device.

The solution is essentially to define, for each device, a family of mappings that convert between device colors and standard CIEXYZ or CIELAB colors. The collection of mappings for a device is known as the 'color-profile' of that device, and each color-profile can be thought of as describing a 'color-space'.

If we know the color-space of the input pixels, and the color space of the output device, then we can convert the colors in the image to their equivalents on the output device.

JuicyPixels does not parse color-profiles or attempt to perform color correction.

The following color space types are recognised:

- sRGB: Standard RGB color space.
- Windows BMP color space: Color space information embedded within a V4 Windows BMP file.
- ICC profile: An ICC color profile.

Constructors

SRGB |
WindowsBitmapColorSpace !ByteString |
ICCProfile !ByteString |

#### Instances

Instances details

Show ColorSpace # |
Instance details Defined in Codec.Picture.Metadata Methods showsPrec :: Int -> ColorSpace -> ShowS # show :: ColorSpace -> String # showList :: [ColorSpace] -> ShowS #
NFData ColorSpace # |
Instance details Defined in Codec.Picture.Metadata Methods rnf :: ColorSpace -> () #
Eq ColorSpace # |
Instance details Defined in Codec.Picture.Metadata Methods (==) :: ColorSpace -> ColorSpace -> Bool # (/=) :: ColorSpace -> ColorSpace -> Bool #

# Functions

lookup :: Keys a -> Metadatas -> Maybe a #

Search a metadata with the given key.

empty :: Metadatas #

Empty metadatas. Favor `mempty`

insert :: (Show a, NFData a) => Keys a -> a -> Metadatas -> Metadatas #

Insert an element in the metadatas, if an element with the same key is present, it is overwritten.

delete :: Keys a -> Metadatas -> Metadatas #

Remove an element of the given keys from the metadatas. If not present does nothing.

singleton :: (Show a, NFData a) => Keys a -> a -> Metadatas #

Create metadatas with a single element.

# Folding

foldl' :: (acc -> Elem Keys -> acc) -> acc -> Metadatas -> acc #

Strict left fold of the metadatas

foldMap :: Monoid m => (Elem Keys -> m) -> Metadatas -> m #

foldMap equivalent for metadatas.

# Helper functions

mkDpiMetadata :: Word -> Metadatas #

Create metadatas indicating the resolution, with DpiX == DpiY

mkSizeMetadata :: Integral n => n -> n -> Metadatas #

Create metadatas holding width and height information.

basicMetadata :: Integral nSize => SourceFormat -> nSize -> nSize -> Metadatas #

Create simple metadatas with Format, Width & Height

simpleMetadata :: (Integral nSize, Integral nDpi) => SourceFormat -> nSize -> nSize -> nDpi -> nDpi -> Metadatas #

Create simple metadatas with Format, Width, Height, DpiX & DpiY

extractExifMetas :: Metadatas -> [(ExifTag, ExifData)] #

Extract all Exif specific metadatas

# Conversion functions

dotsPerMeterToDotPerInch :: Word -> Word #

Conversion from dpm to dpi

dotPerInchToDotsPerMeter :: Word -> Word #

Conversion from dpi to dpm

dotsPerCentiMeterToDotPerInch :: Word -> Word #

Conversion dpcm -> dpi