Codec.Picture.Types
Description
Module providing the basic types for image manipulation in the library. Defining the types used to store all those _Juicy Pixels_
- data Image a = Image {
- imageWidth :: !Int
- imageHeight :: !Int
- imageData :: UArray Int Word8
- data MutableImage s a = MutableImage {}
- data DynamicImage
- = ImageY8 (Image Pixel8)
- | ImageYA8 (Image PixelYA8)
- | ImageRGB8 (Image PixelRGB8)
- | ImageRGBA8 (Image PixelRGBA8)
- | ImageYCbCr8 (Image PixelYCbCr8)
- data PixelType
- type Pixel8 = Word8
- data PixelYA8 = PixelYA8 !Word8 !Word8
- data PixelRGB8 = PixelRGB8 !Word8 !Word8 !Word8
- data PixelRGBA8 = PixelRGBA8 !Word8 !Word8 !Word8 !Word8
- data PixelYCbCr8 = PixelYCbCr8 !Word8 !Word8 !Word8
- class (Pixel a, Pixel b) => ColorConvertible a b where
- promotePixel :: a -> b
- promoteImage :: Image a -> Image b
- class Serialize a => Pixel a where
- canPromoteTo :: a -> PixelType -> Bool
- componentCount :: a -> Int
- pixelBaseIndex :: Image a -> Int -> Int -> Int
- mutablePixelBaseIndex :: MutableImage s a -> Int -> Int -> Int
- promotionType :: a -> PixelType
- pixelAt :: Image a -> Int -> Int -> a
- readPixel :: MutableImage s a -> Int -> Int -> ST s a
- writePixel :: MutableImage s a -> Int -> Int -> a -> ST s ()
- class (Pixel a, Pixel b) => ColorSpaceConvertible a b where
- convertPixel :: a -> b
- convertImage :: Image a -> Image b
- canConvertTo :: (Pixel a, Pixel b) => a -> b -> Bool
Types
Image types
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
| |
data MutableImage s a Source
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
| |
data DynamicImage Source
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. |
Describe pixel kind at runtime
Constructors
| PixelMonochromatic | For 2 bits pixels |
| PixelGreyscale | |
| PixelGreyscaleAlpha | |
| PixelRedGreenBlue8 | |
| PixelRedGreenBlueAlpha8 | |
| PixelYChromaRChromaB8 |
Pixel types
Pixel type storing Luminance (Y) and alpha information on 8 bits. Value are stored in the following order :
- Luminance
- Alpha
Pixel type storing classic pixel on 8 bits Value are stored in the following order :
- Red
- Green
- Blue
data PixelRGBA8 Source
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 |
data PixelYCbCr8 Source
Pixel storing data in the YCbCr colorspace, value are stored in teh following order :
- Y (luminance)
- Cr
- Cb
Constructors
| PixelYCbCr8 !Word8 !Word8 !Word8 |
Type classes
class (Pixel a, Pixel b) => ColorConvertible a b whereSource
Implement upcasting for pixel types
Minimal declaration declaration promotePixel
It is strongly recommanded to overload promoteImage to keep
performance acceptable
Methods
promotePixel :: a -> bSource
Convert a pixel type to another pixel type. This operation should never loss any data.
promoteImage :: Image a -> Image bSource
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 whereSource
Typeclass used to query a type about it's properties regarding casting to other pixel types
Methods
canPromoteTo :: a -> PixelType -> BoolSource
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 -> IntSource
Return the number of component of the pixel
pixelBaseIndex :: Image a -> Int -> Int -> IntSource
Calculate the index for the begining of the pixel
mutablePixelBaseIndex :: MutableImage s a -> Int -> Int -> IntSource
Calculate theindex for the begining of the pixel at position x y
promotionType :: a -> PixelTypeSource
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 -> aSource
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 aSource
Same as pixelAt but for mutable images.
writePixel :: MutableImage s a -> Int -> Int -> a -> ST s ()Source
Write a pixel in a mutable image at position x y
Instances
class (Pixel a, Pixel b) => ColorSpaceConvertible a b whereSource
This class abstract colorspace conversion. This conversion can be lossy, which ColorConvertible cannot
Instances
Helper functions
canConvertTo :: (Pixel a, Pixel b) => a -> b -> BoolSource
Tell if you can convert between two pixel types, both arguments are unused.