added a getpixeldata function that reads a block of 100 x  150. Note that this is probably the best way to read data in python as anything else would not work. Also suspiciously everything reports a zero but I haven't figured it out if it's just my code is buggy or if that block is empty. Are there smaller files we can test on?
Merge branch 'master' of https://github.com/DuKode/OpenIR_AtmosphericCorrection