Copyright	(c) Laurent P René de Cotret 2019 - present
License	BSD3
Maintainer	laurent.decotret@outlook.com
Stability	unstable
Portability	portable
Safe Haskell	Safe-Inferred
Language	Haskell2010

Hakyll.Images.Resize

Description

This module defines two Hakyll compilers. The first one, resizeImageCompiler, is used to resize images to specific dimensions. The aspect ratio might not be the same.

The other compiler, scaleImageCompiler, scales images to fit within a specified box while preserving aspect ratio.

    import Hakyll
    import Hakyll.Images        ( loadImage
                                , resizeImageCompiler
                                , scaleImageCompiler
                                )

    hakyll $ do

        -- Resize all profile pictures with .png extensions to 64x48
        match "profiles/**.png" $ do
            route idRoute
            compile $ loadImage
                >>= resizeImageCompiler 64 48

        -- Scale images to fit within a 600x400 box
        match "images/**" $ do
            route idRoute
            compile $ loadImage
                >>= scaleImageCompiler 600 400

        (... omitted ...)

Synopsis

type Width = Int
type Height = Int
resize :: Width -> Height -> DynamicImage -> DynamicImage
resizeImageCompiler :: Width -> Height -> Item Image -> Compiler (Item Image)
scale :: Width -> Height -> DynamicImage -> DynamicImage
scaleImageCompiler :: Width -> Height -> Item Image -> Compiler (Item Image)
ensureFit :: Width -> Height -> DynamicImage -> DynamicImage
ensureFitCompiler :: Width -> Height -> Item Image -> Compiler (Item Image)

Documentation

type Width = Int Source #

type Height = Int Source #

resize :: Width -> Height -> DynamicImage -> DynamicImage Source #

Resize an image to specified width and height using the bilinear transform. The aspect ratio may not be respected.

In the process, an image is converted to RGBA8. Therefore, some information loss may occur.

resizeImageCompiler :: Width -> Height -> Item Image -> Compiler (Item Image) Source #

Compiler that resizes images to a specific dimensions. Aspect ratio may not be preserved.

match "*.png" $ do
    route idRoute
    compile $ loadImage
        >>= resizeImageCompiler 48 64

Note that in the resizing process, images will be converted to RGBA8. To preserve aspect ratio, take a look at scaleImageCompiler.

scale :: Width -> Height -> DynamicImage -> DynamicImage Source #

Scale an image to a size that will fit in the specified width and height, while preserving aspect ratio. Images might be scaled up as well.

In the process, an image is converted to RGBA8. Therefore, some information loss may occur.

To scale images down only, take a look at ensureFit.

scaleImageCompiler :: Width -> Height -> Item Image -> Compiler (Item Image) Source #

Compiler that rescales images to fit within dimensions. Aspect ratio will be preserved. Images might be scaled up as well.

match "*.tiff" $ do
    route idRoute
    compile $ loadImage
        >>= scaleImageCompiler 48 64

Note that in the resizing process, images will be converted to RGBA8. To ensure images are only scaled down, take a look at ensureFitCompiler.

ensureFit :: Width -> Height -> DynamicImage -> DynamicImage Source #

Scale an image down to a size that will fit in the specified width and height, while preserving aspect ratio.

In the process, an image is converted to RGBA8. Therefore, some information loss may occur.

To scale images up or down, take a look at scale.

ensureFitCompiler :: Width -> Height -> Item Image -> Compiler (Item Image) Source #

Compiler that ensures images will fit within dimensions. Images might be scaled down, but never up. Aspect ratio will be preserved.

match "*.tiff" $ do
    route idRoute
    compile $ loadImage
        >>= ensureFitCompiler 48 64

Note that in the resizing process, images will be converted to RGBA8. To allow the possibility of scaling up, take a look at scaleImageCompiler.