Codec.Picture.Types

Module providing the basic types for image manipulation in the library. Defining the types used to store all those _Juicy Pixels_

Types

Image types

data Image a

Image or pixel buffer, the coordinates are assumed to start from the upper-left corner of the image, with the horizontal position first, then the vertical one.

Constructors

Image

Fields

imageWidth :: !Int

Width of the image in pixels

imageHeight :: !Int

Height of the image in pixels.

imageData :: Vector Word8

The real image, to extract pixels at some position you should use the helpers functions.

Instances

NFData (Image a)

data MutableImage s a

Image or pixel buffer, the coordinates are assumed to start from the upper-left corner of the image, with the horizontal position first, then the vertical one. The image can be transformed in place.

Constructors

MutableImage

Fields

mutableImageWidth :: !Int

Width of the image in pixels

mutableImageHeight :: !Int

Height of the image in pixels.

mutableImageData :: STVector s Word8

The real image, to extract pixels at some position you should use the helpers functions.

Instances

NFData (MutableImage s a)

data DynamicImage

Type allowing the loading of an image with different pixel structures

Constructors

ImageY8 (Image Pixel8)

A greyscale image.

ImageYA8 (Image PixelYA8)

An image in greyscale with an alpha channel.

ImageRGB8 (Image PixelRGB8)

An image in true color.

ImageRGBA8 (Image PixelRGBA8)

An image in true color and an alpha channel.

ImageYCbCr8 (Image PixelYCbCr8)

An image in the colorspace used by Jpeg images.

Instances

NFData DynamicImage

data PixelType

Describe pixel kind at runtime

Constructors

PixelMonochromatic

For 2 bits pixels

PixelGreyscale

PixelGreyscaleAlpha

PixelRedGreenBlue8

PixelRedGreenBlueAlpha8

PixelYChromaRChromaB8

Instances

Eq PixelType

Pixel types

type Pixel8 = Word8

Simple alias for greyscale value in 8 bits.

data PixelYA8

Pixel type storing Luminance (Y) and alpha information on 8 bits. Value are stored in the following order :

• Luminance
• Alpha

Constructors

PixelYA8 !Word8 !Word8

Instances

Storable PixelYA8

Serialize PixelYA8

LumaPlaneExtractable PixelYA8

Pixel PixelYA8

PngSavable PixelYA8

ColorConvertible PixelYA8 PixelRGBA8

ColorConvertible PixelYA8 PixelRGB8

ColorConvertible Pixel8 PixelYA8

TransparentPixel PixelYA8 Pixel8

ColorPlane PixelYA8 PlaneLuma

ColorPlane PixelYA8 PlaneAlpha

data PixelRGB8

Pixel type storing classic pixel on 8 bits Value are stored in the following order :

• Red
• Green
• Blue

Constructors

PixelRGB8 !Word8 !Word8 !Word8

Instances

Storable PixelRGB8

Serialize PixelRGB8

LumaPlaneExtractable PixelRGB8

Pixel PixelRGB8

PngSavable PixelRGB8

BmpEncodable PixelRGB8

ColorSpaceConvertible PixelYCbCr8 PixelRGB8

ColorSpaceConvertible PixelRGB8 PixelYCbCr8

ColorConvertible PixelRGB8 PixelRGBA8

ColorConvertible PixelYA8 PixelRGB8

ColorConvertible Pixel8 PixelRGB8

TransparentPixel PixelRGBA8 PixelRGB8

ColorPlane PixelRGB8 PlaneBlue

ColorPlane PixelRGB8 PlaneGreen

ColorPlane PixelRGB8 PlaneRed

data PixelRGBA8

Pixel type storing a classic pixel, with an alpha component. Values are stored in the following order

• Red
• Green
• Blue
• Alpha

Constructors

PixelRGBA8 !Word8 !Word8 !Word8 !Word8

Instances

Storable PixelRGBA8

Serialize PixelRGBA8

LumaPlaneExtractable PixelRGBA8

Pixel PixelRGBA8

PngSavable PixelRGBA8

BmpEncodable PixelRGBA8

ColorConvertible PixelRGB8 PixelRGBA8

ColorConvertible PixelYA8 PixelRGBA8

ColorConvertible Pixel8 PixelRGBA8

TransparentPixel PixelRGBA8 PixelRGB8

ColorPlane PixelRGBA8 PlaneAlpha

ColorPlane PixelRGBA8 PlaneBlue

ColorPlane PixelRGBA8 PlaneGreen

ColorPlane PixelRGBA8 PlaneRed

data PixelYCbCr8

Pixel storing data in the YCbCr colorspace, value are stored in the following order :

• Y (luminance)
• Cr
• Cb

Constructors

PixelYCbCr8 !Word8 !Word8 !Word8

Instances

Storable PixelYCbCr8

Serialize PixelYCbCr8

LumaPlaneExtractable PixelYCbCr8

Pixel PixelYCbCr8

ColorSpaceConvertible PixelYCbCr8 PixelRGB8

ColorSpaceConvertible PixelRGB8 PixelYCbCr8

ColorPlane PixelYCbCr8 PlaneCb

ColorPlane PixelYCbCr8 PlaneCr

ColorPlane PixelYCbCr8 PlaneLuma

Type classes

class (Pixel a, Pixel b) => ColorConvertible a b where

Implement upcasting for pixel types Minimal declaration declaration promotePixel It is strongly recommanded to overload promoteImage to keep performance acceptable

Methods

promotePixel :: a -> b

Convert a pixel type to another pixel type. This operation should never loss any data.

promoteImage :: Image a -> Image b

Change the underlying pixel type of an image by performing a full copy of it.

Instances

Pixel a => ColorConvertible a a

Free promotion for identic pixel types

ColorConvertible PixelRGB8 PixelRGBA8

ColorConvertible PixelYA8 PixelRGBA8

ColorConvertible PixelYA8 PixelRGB8

ColorConvertible Pixel8 PixelRGBA8

ColorConvertible Pixel8 PixelRGB8

ColorConvertible Pixel8 PixelYA8

class Serialize a => Pixel a where

Typeclass used to query a type about it's properties regarding casting to other pixel types

Methods

canPromoteTo :: a -> PixelType -> Bool

Tell if a pixel can be converted to another pixel, the first value should not be used, and undefined can be used as a valid value.

componentCount :: a -> Int

Return the number of component of the pixel

pixelBaseIndex :: Image a -> Int -> Int -> Int

Calculate the index for the begining of the pixel

mutablePixelBaseIndex :: MutableImage s a -> Int -> Int -> Int

Calculate theindex for the begining of the pixel at position x y

promotionType :: a -> PixelType

Return the constructor associated to the type, again the value in the first parameter is not used, so you can use undefined

pixelAt :: Image a -> Int -> Int -> a

Extract a pixel at a given position, (x, y), the origin is assumed to be at the corner top left, positive y to the bottom of the image

readPixel :: MutableImage s a -> Int -> Int -> ST s a

Same as pixelAt but for mutable images.

writePixel :: MutableImage s a -> Int -> Int -> a -> ST s ()

Write a pixel in a mutable image at position x y

Instances

Pixel PixelRGBA8

Pixel PixelYCbCr8

Pixel PixelRGB8

Pixel PixelYA8

Pixel Pixel8

class (Pixel a, Pixel b) => ColorSpaceConvertible a b where

This class abstract colorspace conversion. This conversion can be lossy, which ColorConvertible cannot

Methods

convertPixel :: a -> b

Pass a pixel from a colorspace (say RGB) to the second one (say YCbCr)

convertImage :: Image a -> Image b

Helper function to convert a whole image by taking a copy it.

Instances

Pixel a => ColorSpaceConvertible a a

ColorSpaceConvertible PixelYCbCr8 PixelRGB8

ColorSpaceConvertible PixelRGB8 PixelYCbCr8

class Pixel a => LumaPlaneExtractable a where

Helper class to help extract a luma plane out of an image or a pixel

Methods

computeLuma :: a -> Pixel8

Compute the luminance part of a pixel

extractLumaPlane :: Image a -> Image Pixel8

Extract a luma plane out of an image. This method is in the typeclass to help performant implementation.

Instances

LumaPlaneExtractable PixelRGBA8

LumaPlaneExtractable PixelYCbCr8

LumaPlaneExtractable PixelRGB8

LumaPlaneExtractable PixelYA8

LumaPlaneExtractable Pixel8

class (Pixel a, Pixel b) => TransparentPixel a b | a -> b where

Class modeling transparent pixel, should provide a method to combine transparent pixels

Methods

dropTransparency :: a -> b

Just return the opaque pixel value

Instances

TransparentPixel PixelRGBA8 PixelRGB8

TransparentPixel PixelYA8 Pixel8

Helper functions

canConvertTo :: (Pixel a, Pixel b) => a -> b -> Bool

Tell if you can convert between two pixel types, both arguments are unused.

pixelMap :: forall a b. (Pixel a, Pixel b) => (a -> b) -> Image a -> Image b

map equivalent for an image, working at the pixel level. Little example : a brightness function for an rgb image

 brightnessRGB8 :: Int -> Image PixelRGB8 -> Image PixelRGB8
 brightnessRGB8 add = pixelMap brightFunction
      where up v = fromIntegral (fromIntegral v + add)
            brightFunction (PixelRGB8 r g b) =
                    PixelRGB8 (up r) (up g) (up b)

dropAlphaLayer :: TransparentPixel a b => Image a -> Image b

For any image with an alpha component (transparency), drop it, returning a pure opaque image.

generateImage

Arguments

:: forall a . Pixel a

=> (Int -> Int -> a)

Generating function, with x and y params.

-> Int

Width in pixels

-> Int

Height in pixels

-> Image a

Create an image given a function to generate pixels. The function will receive value from 0 to width-1 for the x parameter and 0 to height-1 for the y parameter. The coordinate 0,0 is the upper left corner of the image, and (width-1, height-1) the lower right corner.

for example, to create a small gradient image :

 imageCreator :: String -> Image PixelRGB8
 imageCreator path = writePng path $ generateImage pixelRenderer 250 300
    where pixelRenderer x y = PixelRGB8 x y 128

generateFoldImage

Arguments

:: forall a acc . Pixel a

=> (acc -> Int -> Int -> (acc, a))

Function taking the state, x and y

-> acc

Initial state

-> Int

Width in pixels

-> Int

Height in pixels

-> (acc, Image a)

Create an image given a function to generate pixels. The function will receive value from 0 to width-1 for the x parameter and 0 to height-1 for the y parameter. The coordinate 0,0 is the upper left corner of the image, and (width-1, height-1) the lower right corner.

the acc parameter is a user defined one.

The function is called for each pixel in the line from left to right (0 to width - 1) and for each line (0 to height - 1).

Color plane extraction

class ColorPlane pixel planeToken

Class used to describle plane present in the pixel type. If a pixel has a plane description associated, you can use the plane name to extract planes independently.

Instances

ColorPlane PixelRGBA8 PlaneAlpha

ColorPlane PixelRGBA8 PlaneBlue

ColorPlane PixelRGBA8 PlaneGreen

ColorPlane PixelRGBA8 PlaneRed

ColorPlane PixelYCbCr8 PlaneCb

ColorPlane PixelYCbCr8 PlaneCr

ColorPlane PixelYCbCr8 PlaneLuma

ColorPlane PixelRGB8 PlaneBlue

ColorPlane PixelRGB8 PlaneGreen

ColorPlane PixelRGB8 PlaneRed

ColorPlane PixelYA8 PlaneLuma

ColorPlane PixelYA8 PlaneAlpha

data PlaneRed

Define the plane for the red color component

Constructors

PlaneRed

Instances

ColorPlane PixelRGBA8 PlaneRed

ColorPlane PixelRGB8 PlaneRed

data PlaneGreen

Define the plane for the green color component

Constructors

PlaneGreen

Instances

ColorPlane PixelRGBA8 PlaneGreen

ColorPlane PixelRGB8 PlaneGreen

data PlaneBlue

Define the plane for the blue color component

Constructors

PlaneBlue

Instances

ColorPlane PixelRGBA8 PlaneBlue

ColorPlane PixelRGB8 PlaneBlue

data PlaneAlpha

Define the plane for the alpha (transparency) component

Constructors

PlaneAlpha

Instances

ColorPlane PixelRGBA8 PlaneAlpha

ColorPlane PixelYA8 PlaneAlpha

data PlaneLuma

Define the plane for the luma component

Constructors

PlaneLuma

Instances

ColorPlane PixelYCbCr8 PlaneLuma

ColorPlane PixelYA8 PlaneLuma

data PlaneCr

Define the plane for the Cr component

Constructors

PlaneCr

Instances

ColorPlane PixelYCbCr8 PlaneCr

data PlaneCb

Define the plane for the Cb component

Constructors

PlaneCb

Instances

ColorPlane PixelYCbCr8 PlaneCb

extractComponent :: forall px plane. (Pixel px, ColorPlane px plane) => plane -> Image px -> Image Pixel8

Extract a color plane from an image given a present plane in the image examples :

  extractRedPlane :: Image PixelRGB8-> Image Pixel8
  extractRedPlane = extractComponent PlaneRed

unsafeExtractComponent

Arguments

:: forall a . Pixel a

=> Int

The component index, beginning at 0 ending at (componentCount - 1)

-> Image a

Source image

-> Image Pixel8

Extract an image plane of an image, returning an image which can be represented by a gray scale image. If you ask a component out of bound, the error function will be called