That image is 215x161, not 320 x 240, and has color fringing.
Oops, >>email attachment<< is correct 320x240 and very clearly has color fringing.
Online images are evidently subsampled...
Try changing 'prune' from 9 to 7 or 8 in the current version at:
Also change, to see first 9 bytes:
#print(b[0:prune])
print(b[0:9])
Oristo