Vix

Blazing fast image processing for Elixir powered by libvips, the same engine that powers sharp.js.

Perfect For

• Building image processing APIs and services
• Generating thumbnails at scale
• Image manipulation in web applications
• Computer vision preprocessing
• Processing large scientific/satellite images

Features

• High Performance: Uses libvips' demand-driven, horizontally threaded architecture
• Memory Efficient: Processes images in chunks, perfect for large files
• Streaming Support: Read/write images without loading them fully into memory
• Rich Ecosystem: Zero-copy integration with Nx and eVision
• Zero Setup: Pre-built binaries for MacOS and Linux platforms included.
• Auto-updating API: New libvips features automatically available
• Comprehensive Documentation: Type specifications and documentation for 300+ operations

Quick Start

Mix.install([
  {:vix, "~> 0.23"}
])

alias Vix.Vips.{Image, Operation}

# Create a thumbnail and optimize for web
{:ok, thumb} = Operation.thumbnail("profile.jpg", 300)
:ok = Image.write_to_file(thumb, "thumbnail.jpg", Q: 90, strip: true, interlace: true)

👉 Try in Livebook

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Common Operations

Basic Processing

# Reading an image
{:ok, img} = Image.new_from_file("profile.jpg")

# Resize preserving aspect ratio
{:ok, resized} = Operation.resize(img, 0.5)  # 50% of original size

# Crop a section
{:ok, cropped} = Operation.crop(img, 100, 100, 500, 500)

# Rotate with white background
{:ok, rotated} = Operation.rotate(img, 90, background: [255, 255, 255])

# Smart thumbnail (preserves important features)
{:ok, thumb} = Operation.thumbnail("large.jpg", 300, size: :VIPS_SIZE_DOWN, crop: :VIPS_INTERESTING_ATTENTION)

Web Optimization

# Convert to WebP with quality optimization
:ok = Image.write_to_file(img, "output.webp", Q: 80, effort: 4)

# Create progressive JPEG with metadata stripped
:ok = Image.write_to_file(img, "output.jpg", interlace: true, strip: true, Q: 85)

# Generate multiple formats
:ok = Image.write_to_file(img, "photo.avif", Q: 60)
:ok = Image.write_to_file(img, "photo.webp", Q: 80)
:ok = Image.write_to_file(img, "photo.jpg", Q: 85)

Filters & Effects

# Blur
{:ok, blurred} = Operation.gaussblur(img, 3.0)

# Sharpen
{:ok, sharp} = Operation.sharpen(img, sigma: 1.0)

# Grayscale
{:ok, bw} = Operation.colourspace(img, :VIPS_INTERPRETATION_B_W)

Advanced Usage

# Smart thumbnail preserving important features
{:ok, thumb} = Operation.thumbnail(
  "large.jpg",
  300,
  size: :VIPS_SIZE_DOWN, # only downsize, it will just copy if asked to upsize
  crop: :VIPS_INTERESTING_ATTENTION
)

# Process image stream on the fly
{:ok, image} =
  File.stream!("large_photo.jpg", [], 65_536)
  |> Image.new_from_enum()
# use `image` for further operations...

# Stream image to S3
:ok =
  Image.write_to_stream(image, ".png")
  |> Stream.each(&upload_chunk_to_s3/1)
  |> Stream.run()

<!-- TODO: Would be great to add examples for: --> <!-- - Watermarking --> <!-- - Image composition --> <!-- - Batch processing --> <!-- - Text overlay -->

Performance

Libvips very fast and uses very little memory. See the detailed benchmark. Resizing an image is typically 4x-5x faster than using the quickest ImageMagick settings. It can also work with very large images without completely loading them to the memory.

Installation

Add Vix to your dependencies:

def deps do
  [
    {:vix, "~> x.x.x"}
  ]
end

That's it! Vix includes pre-built binaries for MacOS & Linux.

Advanced Setup

Want to use your system's libvips? Set before compilation:

export VIX_COMPILATION_MODE=PLATFORM_PROVIDED_LIBVIPS

See libvips installation guide for more details.

Documentation & Resources

• Complete API Documentation
• Interactive Introduction (Livebook)
• Creating Rainbow Effects (Livebook)
• Auto Document Rotation (Livebook)
• Picture Language from SICP (Livebook)

FAQ

Should I use Vix or Image?

Image is a library which builds on top of Vix.

• Use Image when you need:

  • A more Elixir-friendly API for common operations
  • Higher-level operations like Blurhash
  • Simple, chainable functions for common operations

• Use Vix directly when you need:

  • Advanced VIPS features and fine-grained control
  • Complex image processing pipelines
  • Direct libvips performance and capabilities
  • Lesser dependencies

What image formats are supported?

Out of the box: JPEG, PNG, WEBP, TIFF, SVG, HEIF, GIF, and more. Need others? Just install libvips with the required libraries!

License

MIT License - see LICENSE for details.