Codec.Picture.Repa

Primitive types and operations

data Img a

Img a is an image where the phantom type a indicates the image format

All images are held in a three dimensional repa array. If the image format is only two dimensional (ex: R, G, or B) then the shape is Z :. y :. x :. 1.

imgData :: Img a -> Array D DIM3 Word8

convertImage :: ConvertImage a b => a -> Img b

Converts from JuicyPixels type (Usually Image or DynamicImage to the repa-based Img type.

imgToImage :: Img a -> DynamicImage

Generic interface

readImage :: DecodeImage a => FilePath -> IO (Either String (Img a))

decodeImage :: DecodeImage a => ByteString -> Either String (Img a)

Monomorphic image decoding functions

readImageRGBA :: FilePath -> IO (Either String (Img RGBA))

readImageRGB :: FilePath -> IO (Either String (Img RGB))

readImageR :: FilePath -> IO (Either String (Img R))

readImageG :: FilePath -> IO (Either String (Img G))

readImageB :: FilePath -> IO (Either String (Img B))

decodeImageRGBA :: ByteString -> Either String (Img RGBA)

decodeImageRGB :: ByteString -> Either String (Img RGB)

decodeImageR :: ByteString -> Either String (Img R)

decodeImageG :: ByteString -> Either String (Img G)

decodeImageB :: ByteString -> Either String (Img B)

Image Representations (Phantom Types)

data RGBA

A 32-bit image with full red, green, blue and alpha channels.

The image is stored as Height x Width x ColorChannel.

The color channel is stored in RGBA order. For the common OpenGL ordering users might want to use reverseColorChannel.

Instances

Collapsable RGBA (Word8, Word8, Word8)

Collapsable RGBA (Word8, Word8, Word8, Word8)

data RGB

A 24-bit image with red, green and blue channels

data R

An all-red image

data G

An all-green image

data B

An all-blue image

Helper Functions (useful for OpenGL etc.)

toForeignPtr :: Img RGBA -> (ForeignPtr Word8, Int, Int)

O(n) returning (pointer, length, offset)

toByteString :: Img a -> ByteString

toByteString arr converts images to bytestrings, which is often useful for Gloss.

toUnboxed :: Img a -> Vector Word8

O(n) Convert to an unboxed vector

class Collapsable a t where

Methods

collapseColorChannel :: Img a -> Array D DIM2 t

Converts the color channel into a tuple:

Instances

Collapsable RGBA (Word8, Word8, Word8)

Collapsable RGBA (Word8, Word8, Word8, Word8)

onImg :: (Array D DIM3 Word8 -> Array D DIM3 Word8) -> Img a -> Img a

reverseColorChannel :: Img a -> Img a

By default, the color channel for RGBA indexes 0 -> R, 1 -> G, 2 -> B, 3 -> A. This is the AGBR byte ordering in OpenGL. For rendering with OpenGL's RGBA PixelFormat be sure to call reverseColorChannel before converting to a Vector.

flipHorizontally :: Array D DIM3 Word8 -> Array D DIM3 Word8

Flip an image horizontally

flipVertically :: Array D DIM3 Word8 -> Array D DIM3 Word8

Flip an image vertically

vConcat :: [Img a] -> Img a

Combines a list of images such that the first image is on top, then the second, and so on.

hConcat :: [Img a] -> Img a

Combines a list of images such that the first image is on the left, then the second, and so on.

Saving Images

module Codec.Picture.Saving

Internal Functionallity (exported for advanced uses)

class ToRGBAChannels a where

Methods

toRGBAChannels :: a -> PixelRGBA8

Instances

ToRGBAChannels Pixel8

ToRGBAChannels PixelYA8

ToRGBAChannels PixelRGB8

ToRGBAChannels PixelYCbCr8

ToRGBAChannels PixelRGBA8