Safe Haskell | None |
---|---|
Language | Haskell2010 |
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
- data Metadatas
- data Keys a where
- Gamma :: Keys Double
- Format :: Keys SourceFormat
- DpiX :: Keys Word
- DpiY :: Keys Word
- Width :: Keys Word
- Height :: Keys Word
- Title :: Keys String
- Description :: Keys String
- Author :: Keys String
- Copyright :: Keys String
- Software :: Keys String
- Comment :: Keys String
- Disclaimer :: Keys String
- Source :: Keys String
- Warning :: Keys String
- Exif :: !ExifTag -> Keys ExifData
- Unknown :: !String -> Keys Value
- data Value
- data Elem k = (Show a, NFData a) => !(k a) :=> a
- data SourceFormat
- 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
- dotsPerMeterToDotPerInch :: Word -> Word
- dotPerInchToDotsPerMeter :: Word -> Word
- dotsPerCentiMeterToDotPerInch :: Word -> Word
Types
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.
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. Relyiung on the metadata for this information can void the full decomrpession of the image. Ignored for image writing.Unknown
unlikely to be decoded, but usefull for metadata writingExif
Exif tag and associated data.
Gamma :: Keys Double | |
Format :: Keys SourceFormat | |
DpiX :: Keys Word | |
DpiY :: Keys Word | |
Width :: Keys Word | |
Height :: Keys Word | |
Title :: Keys String | |
Description :: Keys String | |
Author :: Keys String | |
Copyright :: Keys String | |
Software :: Keys String | |
Comment :: Keys String | |
Disclaimer :: Keys String | |
Source :: Keys String | |
Warning :: Keys String | |
Exif :: !ExifTag -> Keys ExifData | |
Unknown :: !String -> Keys Value |
Encode values for unknown information
Element describing a metadata and it's (typed) associated value.
data SourceFormat #
Type describing the original file format of the ilfe.
Functions
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
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
Conversion functions
dotsPerMeterToDotPerInch :: Word -> Word #
Conversion from dpm to dpi
dotPerInchToDotsPerMeter :: Word -> Word #
Conversion from dpi to dpm
dotsPerCentiMeterToDotPerInch :: Word -> Word #
Conversion dpcm -> dpi