Chris Hengge wrote: > alist = difference(image1,image2) > a = [b for b in alist.getdata() if b != (0,0,0)] > if len(a) != 0: > print "Not the same" > > is much slower then (9x) > > if im1.tostring() != im2.tostring() > print "something changed!" > > This loop itself is fairly slow by itself though.. I'm going to try > and see if there is a faster way. Chris, are you sure you know what a loop is? The only loop here is in the list comprehension. 'if' is not a loop. 'for' and 'while' are. In computer science, it's important to be clear in your use of terminology.
It makes sense that my example was slow. I didn't really think to try converting them to strings. Any time you're trying to compare pixel values, it's going to take a while, cause remember, a 1024X768 image has 786,432 different pixels. I think your tostring comparison may be your best bet. _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
