Copyright	(c) 2020 Sam Protas
License	BSD3
Maintainer	Sam Protas <sam.protas@gmail.com>
Stability	experimental
Portability	portable
Safe Haskell	None
Language	Haskell2010

Codec.Picture.Blurhash.Internal.Decode

Description

Internal Blurhash decoding implementation.

Note: This is an internal module not subject to PVP adherence.

Synopsis

data DecodeConfig = DecodeConfig {
- punch :: Float
- outputWidth :: Int
- outputHeight :: Int
}
data DecodeError
- = InvalidCharacterError Word8
- | InvalidHashLength
decodeConfigDefault :: DecodeConfig
decodeRGB8 :: ByteString -> Either DecodeError (Image PixelRGB8)
decodeRGB8WithConfig :: DecodeConfig -> ByteString -> Either DecodeError (Image PixelRGB8)
decodeLinear :: ByteString -> Either DecodeError (Image PixelRGBF)
decodeLinearWithConfig :: DecodeConfig -> ByteString -> Either DecodeError (Image PixelRGBF)
decodePixel :: Vector PixelRGBF -> Int -> Int -> Int -> Int -> Int -> Int -> PixelRGBF
base83DecodeTagged :: ByteString -> Either DecodeError Int

Documentation

data DecodeConfig Source #

Configuration for how to decode a blurhash to an image.

>>> let myDecodeConfig = decodeConfigDefault { punch = 1.1, outputWidth = 64, outputHeight = 64}

Constructors

DecodeConfig
Fields punch :: Float Adjusts the contrast of the decoded image. Larger values mean more contrast. See `DecodeConfig` for example use with record update syntax. outputWidth :: Int Output image pixel width. See `DecodeConfig` for example use with record update syntax. outputHeight :: Int Output image pixel height. See `DecodeConfig` for example use with record update syntax.

Instances

Show DecodeConfig Source #
Instance details Defined in Codec.Picture.Blurhash.Internal.Decode Methods showsPrec :: Int -> DecodeConfig -> ShowS # show :: DecodeConfig -> String # showList :: [DecodeConfig] -> ShowS #
Generic DecodeConfig Source #
Instance details Defined in Codec.Picture.Blurhash.Internal.Decode Associated Types type Rep DecodeConfig :: Type -> Type # Methods from :: DecodeConfig -> Rep DecodeConfig x # to :: Rep DecodeConfig x -> DecodeConfig #
type Rep DecodeConfig Source #
Instance details Defined in Codec.Picture.Blurhash.Internal.Decode type Rep DecodeConfig = D1 (MetaData "DecodeConfig" "Codec.Picture.Blurhash.Internal.Decode" "JuicyPixels-blurhash-0.1.0.0-DaqpokmttsPFp5F95koWnn" False) (C1 (MetaCons "DecodeConfig" PrefixI True) (S1 (MetaSel (Just "punch") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Float) :: (S1 (MetaSel (Just "outputWidth") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int) :: S1 (MetaSel (Just "outputHeight") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int))))

data DecodeError Source #

Decoding error types.

Constructors

InvalidCharacterError Word8	The provided blurhash included an un-decodable byte.
InvalidHashLength	The provided blurhash length was wrong.

Instances

Show DecodeError Source #
Instance details Defined in Codec.Picture.Blurhash.Internal.Decode Methods showsPrec :: Int -> DecodeError -> ShowS # show :: DecodeError -> String # showList :: [DecodeError] -> ShowS #
Generic DecodeError Source #
Instance details Defined in Codec.Picture.Blurhash.Internal.Decode Associated Types type Rep DecodeError :: Type -> Type # Methods from :: DecodeError -> Rep DecodeError x # to :: Rep DecodeError x -> DecodeError #
type Rep DecodeError Source #
Instance details Defined in Codec.Picture.Blurhash.Internal.Decode type Rep DecodeError = D1 (MetaData "DecodeError" "Codec.Picture.Blurhash.Internal.Decode" "JuicyPixels-blurhash-0.1.0.0-DaqpokmttsPFp5F95koWnn" False) (C1 (MetaCons "InvalidCharacterError" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Word8)) :+: C1 (MetaCons "InvalidHashLength" PrefixI False) (U1 :: Type -> Type))

decodeConfigDefault :: DecodeConfig Source #

A reasonable default configuration for decoding.

>>> punch decodeConfigDefault == 1
True

>>> outputWidth decodeConfigDefault == 32
True

>>> outputHeight decodeConfigDefault == 32
True

decodeRGB8 Source #

Arguments

:: ByteString	The blurhash
-> Either DecodeError (Image PixelRGB8)

Decode a blurhash into an Image PixelRGB8. Calls decodeRGB8WithConfig with decodeConfigDefault.

When in doubt, use this function to decode a blurhash.

decodeRGB8WithConfig Source #

Arguments

:: DecodeConfig
-> ByteString	The blurhash.
-> Either DecodeError (Image PixelRGB8)

Decode a blurhash into an Image PixelRGB8 given a DecodeConfig

decodeLinear Source #

Arguments

:: ByteString	The blurhash
-> Either DecodeError (Image PixelRGBF)

Decode a blurhash into an Image PixelRGBF. Calls decodeLinearWithConfig with decodeConfigDefault.

Note: Blurhash implementations use a non-naive PixelRGBF to PixelRGB8 conversion. If your ultimate goal is to end up with an Image PixelRGB8, be careful using this function and scaling pixels by 255 as you will get different results.

decodeLinearWithConfig Source #

Arguments

:: DecodeConfig
-> ByteString	The blurhash
-> Either DecodeError (Image PixelRGBF)

Decode a blurhash into an Image PixelRGBF given a DecodeConfig.

Note: Blurhash implementations use a non-naive PixelRGBF to PixelRGB8 conversion. If your ultimate goal is to end up with an Image PixelRGB8, be careful using this function and scaling pixels by 255 as you will get different results.

decodePixel :: Vector PixelRGBF -> Int -> Int -> Int -> Int -> Int -> Int -> PixelRGBF Source #

Helper function to decode a single pixel.

base83DecodeTagged :: ByteString -> Either DecodeError Int Source #

Helper function to decode a base83 value or return an errorl