https://bugzilla.wikimedia.org/show_bug.cgi?id=16583
Wolfram Schmied <[email protected]> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |[email protected] --- Comment #14 from Wolfram Schmied <[email protected]> 2009-11-27 00:39:22 UTC --- (In reply to comment #3) > It appears that the check, as currently coded, will have > a false positive rate of slightly over 1 in 4096 files, > assuming a random distribution of octets 16 bits, not 12, and you have to multiply by 1024, which gives us a false positive rate for random files on the order of 2^-6 ~= 1.7 %. That was corroborated by a little experiment I did. I measured 1.8 % for a set of metadata-free PNGs created by resizing 1498 JPEGs from my photo collection to 160x120 and converting to PNG. The very low rate seen by [email protected] (comment #11) was apparently the result of large metadata headers. The original JPEG photos I used in my sample all have decidely non-random headers of ~8k. -- Configure bugmail: https://bugzilla.wikimedia.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are the assignee for the bug. You are on the CC list for the bug. _______________________________________________ Wikibugs-l mailing list [email protected] https://lists.wikimedia.org/mailman/listinfo/wikibugs-l
