pluto: A Crystal repository from sdogruyol

A fast and convenient image processing library

Currently supported

Image formats
- JPEG (through libjpeg-turbo)
- PNG (through libspng)
- PPM
- StumpyCore
- WebP (through libwebp)
Image operations
- Bilinear resize
- Box blur
- Brightness
- Channel swap
- Contrast
- Crop
- Gaussian blur
- Horizontal blur
- Vertical blur

Installation

Add the dependency to your shard.yml

dependencies:
  pluto:
    github: phenopolis/pluto

Run shards install

Usage

Basic

require "pluto"

# Formats requiring linkinkg a C library must be explicitly `require`d
require "pluto/format/jpeg"
require "pluto/format/png"
require "pluto/format/webp"

image = File.open("lib/pluto_samples/pluto.png") do |file|
  Pluto::ImageRGBA.from_png(file)
end

image.contrast(-100)  # Creates a new object
image.contrast!(-100) # Modifies the existing object

io = IO::Memory.new
image.to_jpeg(io)
io.rewind
File.write("output.jpeg", io)

StumpyCore

Pluto can convert to and from StumpyCore Canvas objects, so any format that Stumpy supports can be usable with Pluto as well.

require "pluto"
require "stumpy_png"

canvas = StumpyPNG.read("lib/pluto_samples/pluto.png") # => StumpyCore::Canvas
image = Pluto::ImageRGBA.new(canvas)                   # => Pluto::ImageRGBA
image.to_stumpy                                        # => StumpyCore::Canvas

Note

Converting from a StumpyCore::Canvas created from a 16-bit image will result in a loss of information, since Pluto currently only supports 8 bit.

See the API or the spec/ folder for more examples

Benchmarks

Hardware: Intel Core i7-6700K (4 cores/8 threads, 4.2 GHz).
Software: Arch Linux x86_64.

	Time	Memory
from_jpeg(jpeg_bytes)	2.09ms	2.05MiB
from_jpeg(jpeg_io)	1.99ms	2.08MiB
from_png(png_bytes)	3.45ms	2.35MiB
from_png(png_io)	3.61ms	2.57MiB
from_ppm(ppm_bytes)	799.44µs	1.17MiB
from_ppm(ppm_io)	2.45ms	1.2MiB
from_webp(webp_bytes)	3.02ms	1.17MiB
from_webp(webp_io)	2.88ms	1.27MiB
to_jpeg(IO::Memory.new)	3.35ms	964kiB
to_lossless_webp(IO::Memory.new)	105.68ms	1.23MiB
to_lossy_webp(IO::Memory.new)	21.21ms	1.2MiB
to_png(IO::Memory.new)	36.46ms	1.3MiB
to_ppm(IO::Memory.new)	2.34ms	2.0MiB
bilinear_resize!(640, 480)	6.21ms	1.17MiB
box_blur!(10)	7.74ms	600kiB
brightness!(1.4)	1.84ms	0B
channel_swap!(:red, :blue)	63.0ns	0B
contrast!(128)	2.03ms	0B
crop!(200, 200, 100, 100)	29.62µs	100kiB
gaussian_blur!(10)	23.01ms	1.75MiB
horizontal_blur!(10)	3.17ms	300kiB
vertical_blur!(10)	4.51ms	300kiB

Note

Tested with the latest release.

Contributing

Fork it (https://github.com/phenopolis/pluto/fork)
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create a new Pull Request

sdogruyol/pluto