Graphics.Image.Interface.Vector

Construction

makeImage

Arguments

:: Array VU cs Double

=> (Int, Int)

(m rows, n columns) - dimensions of a new image.

-> ((Int, Int) -> Pixel cs Double)

A function that takes (i-th row, and j-th column) as an argument and returns a pixel for that location.

-> Image VU cs Double

Create an image with VU (Vector Unboxed) representation and pixels of Double precision. Note, that for Double precision pixels it is essential to keep values normalized in the [0, 1] range in order for an image to be written to file properly.

>>> let grad_gray = makeImage (200, 200) (\(i, j) -> PixelY (fromIntegral i)/200 * (fromIntegral j)/200)

Because all Pixels and Images are installed into Num, above is equivalent to:

>>> let grad_gray = makeImage (200, 200) (\(i, j) -> PixelY $ fromIntegral (i*j)) / (200*200)
>>> writeImage "images/grad_gray.png" grad_gray

Creating color images is just as easy.

>>> let grad_color = makeImage (200, 200) (\(i, j) -> PixelRGB (fromIntegral i) (fromIntegral j) (fromIntegral (i + j))) / 400
>>> writeImage "images/grad_color.png" grad_color

fromUnboxedVector :: Array VU cs e => (Int, Int) -> Vector (Pixel cs e) -> Image VU cs e

Construct a two dimensional image with m rows and n columns from a flat Unboxed Vector of length k. It is a O(1) opeartion. Make sure that m * n = k.

>>> fromUnboxedVector (200, 300) $ generate 60000 (\i -> PixelY $ fromIntegral i / 60000)
<Image VectorUnboxed Luma: 200x300>

toUnboxedVector :: Array VU cs e => Image VU cs e -> Vector (Pixel cs e)

Convert an image to a flattened Unboxed Vector. It is a O(1) opeartion.

>>> toUnboxedVector $ makeImage (3, 2) (\(i, j) -> PixelY $ fromIntegral (i+j))
fromList [<Luma:(0.0)>,<Luma:(1.0)>,<Luma:(1.0)>,<Luma:(2.0)>,<Luma:(2.0)>,<Luma:(3.0)>]

IO

readImageY :: FilePath -> IO (Image VU Y Double)

Read image as luma (brightness).

readImageYA :: FilePath -> IO (Image VU YA Double)

Read image as luma with Alpha channel.

readImageRGB :: FilePath -> IO (Image VU RGB Double)

Read image in RGB colorspace.

readImageRGBA :: FilePath -> IO (Image VU RGBA Double)

Read image in RGB colorspace with Alpha channel.

Representation

data VU

Unboxed Vector representation.

Constructors

VU

Instances

Show VU

Exchangable VU RS

O(1) - Changes to Repa representation.

Exchangable VU RP

O(1) - Changes to Repa representation.

Exchangable RS VU

O(1) - Changes to Vector representation.

Exchangable RP VU

O(1) - Changes to Vector representation.

ManifestArray VU cs e => MutableArray VU cs e

ManifestArray VU cs e => SequentialArray VU cs e

Array VU cs e => ManifestArray VU cs e

Elt VU cs e => Array VU cs e

data Image VU

• = VScalar !(Pixel cs e)
• | VUImage !Int !Int !(Vector (Pixel cs e))

type Elt VU cs e = (ColorSpace cs, Num e, Unbox e, Typeable * e, Unbox (PixelElt cs e), Unbox (Pixel cs e))

data MImage st VU cs e

• = MVImage !Int !Int (MVector st (Pixel cs e))
• | MVScalar (MVector st (Pixel cs e))