Skip to content

Instantly share code, notes, and snippets.

@remvee

remvee/image-size.rb

Created June 4, 2013 11:46
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save remvee/5705345 to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save remvee/5705345 to your computer and use it in GitHub Desktop.
Download ZIP
Raw
image-size.rb
# PNG
IO.read('image.png')[0x10..0x18].unpack('NN')
#=> [320, 200]
# GIF
IO.read('image.gif')[6..10].unpack('SS')
#=> [320, 200]
# BMP
d = IO.read('image.bmp')[14..28]
d[0] == 40 ? d[4..-1].unpack('LL') : d[4..8].unpack('SS')
#=> [320, 200]
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment