Codec.Picture.Blurhash.Internal.Decode

Internal Blurhash decoding implementation.

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

Documentation

data DecodeConfig

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

Defined in Codec.Picture.Blurhash.Internal.Decode

Methods

showsPrec :: Int -> DecodeConfig -> ShowS

show :: DecodeConfig -> String

showList :: [DecodeConfig] -> ShowS

Generic DecodeConfig

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

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

Decoding error types.

Constructors

InvalidCharacterError Word8

The provided blurhash included an un-decodable byte.

InvalidHashLength

The provided blurhash length was wrong.

Instances

Show DecodeError

Defined in Codec.Picture.Blurhash.Internal.Decode

Methods

showsPrec :: Int -> DecodeError -> ShowS

show :: DecodeError -> String

showList :: [DecodeError] -> ShowS

Generic DecodeError

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

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

A reasonable default configuration for decoding.

>>> punch decodeConfigDefault == 1
True

>>> outputWidth decodeConfigDefault == 32
True

>>> outputHeight decodeConfigDefault == 32
True

decodeRGB8

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

Arguments

:: DecodeConfig

-> ByteString

The blurhash.

-> Either DecodeError (Image PixelRGB8)

Decode a blurhash into an Image PixelRGB8 given a DecodeConfig

decodeLinear

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

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

Helper function to decode a single pixel.

base83DecodeTagged :: ByteString -> Either DecodeError Int

Helper function to decode a base83 value or return an errorl