QRio

QRio is a QR code decoder for Ruby

QRio can extract QR contents in one step:

require 'qrio'
puts Qrio::Qr.load("some-image.png").qr.text

If you know / are curious about the decoding process, QRio can generate an image illustrating the intermediate steps to decoding:

require 'qrio'
qr = Qrio::Qr.load("some-image.png")

qr.save_image(
  "some-image-annotated.png",
  :crop => true,      # crop output image to detected QR bounds
  :annotate => [
    :finder_patterns, # outline detected finder patterns
    :angles           # draw lines connecting finder pattern centers
  ]
)

• Ruby 1.9.2 (will be backported to 1.8.7)
• ChunkyPNG (tested with version 1.2.0)

NOTE : QRio is not yet fully functional. If you'd like to help out, fork and submit a tested pull request. :)

• support numeric / alphanumeric / kanji mode QR codes
• refine alignment pattern location and adjust module sampling grid accordingly
• error correction support
• support more image formats (limited to PNG at the moment)
• native thresholding for input images
• support more QR versions
• speed improvements

Yeah, it's coming along. Here's what should be working now:

• find and extract a QR code from an image. I've been cheating somewhat, using image magick to threshold the image for me:

  convert raw.jpg -colorspace Gray -lat 90x90-3% -median 1x1 cooked.png
  

• detect and correct orientation of extracted QR

• extract modules via a sampling grid

• extract raw bytes from data / error correction blocks

• de-interlace blocks into final bitstream

• extract text from bitstream (ascii mode only)