ruby challenge 7


This challenge gives you a picture with the a weird horizontal grey streak running through it. Obviously something hidden in the image data. I originally found the direction for this solution by converting the image to a bitmap and opening it in a hex editor. However it is much easier to extract the message with ImageMagick, or in this case RMagic the ruby bindings for ImageMagick. This ones a little tricky it is actually a puzzle in a puzzle. I had a solution last night that was kinda long and I knew I could do better, so this morning I completely rewrote it at less then half it original length.

require 'RMagick'
include Magick 
rPix ="./oxygen.png").crop!(0, 45, 609, 7).sample!(87,7)
pixDat = rPix.export_pixels_to_str(0, 0, 87, 1, "R")
puts pixDat.scan(/[0-9]+/).collect{|ascii|ascii.to_i.chr}.join

I cheated a little, I used Gimp to check geometry and get the numbers used in the script. I could have scripted the whole thing but that would have added a couple more lines.

Next: challenge 8; working hard?


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