Codec.Picture.Blurhash.Internal.Encode

Internal Blurhash encoding implementation.

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

Documentation

data EncodeConfig

Configuration for how to encode an image into a blurhash.

Create custom configs using record update syntax and encodeConfigDefault.

>>> let myEncodeConfig = encodeConfigDefault { componentsX = 4, componentsY = 3 }

Constructors

EncodeConfig

Fields

• componentsX :: !Int

  Number of components along the X axis.

  See EncodeConfig for example use with record update syntax.

• componentsY :: !Int

  Number of components along the Y axis.

  See EncodeConfig for example use with record update syntax.

Instances

Show EncodeConfig

Defined in Codec.Picture.Blurhash.Internal.Encode

Methods

showsPrec :: Int -> EncodeConfig -> ShowS

show :: EncodeConfig -> String

showList :: [EncodeConfig] -> ShowS

Generic EncodeConfig

Defined in Codec.Picture.Blurhash.Internal.Encode

Associated Types

type Rep EncodeConfig :: Type -> Type

Methods

from :: EncodeConfig -> Rep EncodeConfig x

to :: Rep EncodeConfig x -> EncodeConfig

type Rep EncodeConfig

Defined in Codec.Picture.Blurhash.Internal.Encode

type Rep EncodeConfig = D1 (MetaData "EncodeConfig" "Codec.Picture.Blurhash.Internal.Encode" "JuicyPixels-blurhash-0.1.0.0-DaqpokmttsPFp5F95koWnn" False) (C1 (MetaCons "EncodeConfig" PrefixI True) (S1 (MetaSel (Just "componentsX") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Int) :*: S1 (MetaSel (Just "componentsY") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Int)))

data EncodeError

Encoding error types.

Constructors

InvalidComponents

The provided config components were invalid.

B83EncodingError Int Int

The provided number cannot be base83 encoded into the provided length.

Instances

Show EncodeError

Defined in Codec.Picture.Blurhash.Internal.Encode

Methods

showsPrec :: Int -> EncodeError -> ShowS

show :: EncodeError -> String

showList :: [EncodeError] -> ShowS

Generic EncodeError

Defined in Codec.Picture.Blurhash.Internal.Encode

Associated Types

type Rep EncodeError :: Type -> Type

Methods

from :: EncodeError -> Rep EncodeError x

to :: Rep EncodeError x -> EncodeError

type Rep EncodeError

Defined in Codec.Picture.Blurhash.Internal.Encode

type Rep EncodeError = D1 (MetaData "EncodeError" "Codec.Picture.Blurhash.Internal.Encode" "JuicyPixels-blurhash-0.1.0.0-DaqpokmttsPFp5F95koWnn" False) (C1 (MetaCons "InvalidComponents" PrefixI False) (U1 :: Type -> Type) :+: C1 (MetaCons "B83EncodingError" PrefixI False) (S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int) :*: S1 (MetaSel (Nothing :: Maybe Symbol) NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 Int)))

encodeConfigDefault :: EncodeConfig

A reasonable default configuration for encoding.

>>> componentsX encodeConfigDefault == 4
True

>>> componentsY encodeConfigDefault == 4
True

checkComponent :: Int -> Either EncodeError Int

A helper funciton to validate the provided encoding component count.

encodeDynamic :: DynamicImage -> Either EncodeError ByteString

Encode a DynamicImage to a blurhash. Calls encodeDynamicWithConfig with encodeConfigDefault.

Note: Relies on convertRGB8 before proceding with the standard Blurhash algorithm.

encodeDynamicWithConfig :: EncodeConfig -> DynamicImage -> Either EncodeError ByteString

Encode a DynamicImage to a blurhash with a given an EncodeConfig.

Note: Relies on convertRGB8 before proceding with the standard Blurhash algorithm.

encodeRGB8 :: Image PixelRGB8 -> Either EncodeError ByteString

Encode an Image PixelRGB8 to a blurhash. Calls encodeRGB8WithConfig with encodeConfigDefault.

Note: This is the most direct port of other language's implementation's default encoding function.

encodeRGB8WithConfig :: EncodeConfig -> Image PixelRGB8 -> Either EncodeError ByteString

Encode an Image PixelRGB8 to a blurhash given an EncodeConfig.

Note: This is the most direct port of other languages implementation's encoding function.

encodeLinear :: Image PixelRGBF -> Either EncodeError ByteString

Encode an Image PixelRGBF to a blurhash. Calls encodeLinearWithConfig with encodeConfigDefault.

Note: Blurhash implementations use a non-naive PixelRGB8 to PixelRGBF conversion. Beware that using promotePixel or promoteImage from ColorConvertible to convert an Image PixelRGB8 to an Image PixelRGBF before using encodeLinear will give different results than encodeRGB8.

encodeLinearWithConfig :: EncodeConfig -> Image PixelRGBF -> Either EncodeError ByteString

Encode an Image PixelRGBF to a blurhash given an EncodeConfig.

Note: Blurhash implementations use a non-naive PixelRGB8 to PixelRGBF conversion. Beware that using promotePixel or promoteImage from ColorConvertible to convert an Image PixelRGB8 to an Image PixelRGBF before using encodeLinearWithConfig will give different results than encodeRGB8WithConfig.

base83EncodeTagged

Arguments

:: Int

toEncode

-> Int

encoded length

-> Either EncodeError Builder

Helper function to encode a base83 value or return an error.

encodeComponents :: Int -> Int -> Image PixelRGBF -> EncodedComponents

Encode encode the color components.

encodeComponent :: Int -> Int -> Float -> Image PixelRGBF -> PixelRGBF

Encode a single color component.

data EncodedComponents

Intermediate data for calculating color components and macAC in one pass.

Constructors

EncodedComponents !(DList PixelRGBF) !Float

encodeDcValue :: PixelRGBF -> Int

Helper function for encoding the DC value.

encodeAcValue :: Float -> PixelRGBF -> Int

Helper function for encoding an AC value.