error_level_difference(string, int, int, int)
filename: Filename of the image
iterations: Number of iterations to run ELD.
qualityV: Starting quality value. Diminishes over each iteration
scale: Scales the pixel values. Makes differing artifacts easier to see.
ACKNOWLEDGEMENTS: Hany Farid, for his papers and research on digital forensics.
Sungjoo Ha (shurain), for his starting code on ELA.
Photo credit: http://imgur.com/user/ANewBadlyPhotoshoppedPhotoofMichaelCeraEveryday