Imagex

Load and save images, using libjpeg, libpng, libjxl, libtiff, and poppler as backends. Formats supported include: jpeg, png, bmp, jpeg-xl, ppm, tiff, pdf.

Where possible, yielding NIFs are used so that it plays nice with BEAM VM's scheduler (WIP).

Install

Please ensure that libjpeg, libpng, libjxl, libtiff, and libpoppler are installed.

defp deps do
  [
    {:imagex, "~> 0.1.0", github: "woohp/imagex", branch: "master"}
  ]
end

Usage

To load an image file (as an Nx.Tensor)

{:ok, image} = Imagex.open("lena.jpg")

or load from memory

bytes = File.read!("test/lena.jpg")
{:ok, image} = Imagex.decode(bytes)

Decode as a specific format

bytes = File.read!("lena.png")
{:ok, image} = Imagex.decode(bytes, format: :png)

Save an image as a file

image = Nx.tensor(...)
Imagex.save(image, "foo.png")  # the format is inferred from the file extension

or save to memory

compressed = Imagex.encode(image, :jpeg)

To work with pdf files

bytes = File.read!("lena.pdf")
{:ok, pdf_document} = Imagex.decode(bytes, format: :pdf)
for i <- 0..pdf_document.num_pages-1 do
  {:ok, image} = Imagex.Pdf.render_page(pdf_document, i, dpi: 150)
end

and similarly, work with tiff files

bytes = File.read!("lena.tiff")
{:ok, tiff_document} = Imagex.decode(bytes, format: :tiff)
for i <- 0..tiff_document.num_pages-1 do
  {:ok, image} = Imagex.Tiff.render_page(tiff_document, i)
end