png

About

png is a pure-ruby PNG library. It lets you write a PNG without any C libraries. Of course it is “slow”.

Installing png

Just install the gem:

$ sudo gem install png

Using png

require 'png'

canvas = PNG::Canvas.new 200, 200

# Set a point to a color
canvas[100, 100] = PNG::Color::Black

# draw an anti-aliased line
canvas.line 50, 50, 100, 50, PNG::Color::Blue

png = PNG.new canvas
png.save 'blah.png'