Genetic Algorithm Helps Identify Criminals

Ponca City, We love you writes to tell us that a new software approach to police sketch artists is finding surprising success in a trial run of 15 police departments in the UK and a few other sites. The software borrows principles from evolution with an interactive genetic algorithm that progressively changes as witnesses try to remember specific details. Current field trials are reporting an increase in successful identification by as much as double conventional methods. A short video with a few working shots of the new "EFIT-V" system is also available on YouTube. "[Researcher Christopher Solomon]'s software generates its own faces that progressively evolve to match the witness' memories. The witness starts with a general description such as 'I remember a young white male with dark hair.' Nine different computer-generated faces that roughly fit the description are generated, and the witness identifies the best and worst matches. The software uses the best fit as a template to automatically generate nine new faces with slightly tweaked features, based on what it learned from the rejected faces. 'Over a number of generations, the computer can learn what face you're looking for,' says Solomon. The mathematics underlying the software is borrowed from Solomon's experience using optics to image turbulence in the atmosphere in the 1990s."

Comments

Re:What's genetic about that?

[Cyberax]

Uhm....

http://en.wikipedia.org/wiki/Genetic_algorithm ?

The word 'genetic' itself has nothing to do with DNA.

GA vs. Hillclimbing

[jockeys]

it seems to me that if you pick the best face from each "generation" and then randomly modify it and pick the best from the next generation, you are merely hillclimbing:
http://en.wikipedia.org/wiki/Hill_climbing and not using a proper GA. This seems to be something that the EigenFit package does.

TFA says that up to six faces may be "bred" together resulting in a new generation, which would indeed be genetic, so the EvoFit package seems to be genuinely genetic.

TFA is unsurprisingly short on details, but it seems to me that EigenFit is using hillclimbing (at least partially) while EvoFit is using shotgun-genetic.

Re:GA vs. Hillclimbing

[eh2o]

This method could be modified to avoid the prompting problem. Essentially the entire test can be buried in noise (i.e., random faces) so that the subject is never aware of the convergence process. It should also be possible to modify it to detect when the subject has insufficient information to identify the target. These sorts of techniques are quite common in experimental psychology when you need to suppress adaptation effects or do testing for medical purposes where the subject can't be trusted to be truthful.

Does it swim?

[bugnuts]

Yes: Is it a frog?
No: Please enter the type of animal.

This article reminds me of the old Animal game, where it does a binary search for whatever type of animal you're thinking. It's been expanded to handle all types of nouns, with a 15-questions interface that is uncanny.

For another computer-generated facial reconstruction test, take a look at the mona lisa.

You got that right.

[NoYob]

I was thinking of a test case for this - the picture of Solomon didn't impress me one bit. Now, you can't have folks mugging test subjects or other violent things BUT there is way.

The test case:

Get a group of test subjects - college students are always great for this. Have your "assailant" run up to the subject and Yell, "Hi!" and then hand the "victim" a flower and then run off. Right then and there, the "victim" goes a "files a police report" with the researchers following typical police procedure.

After about a thousand tests on different subjects with statistically significant positive results, then and only then, will I start to believe this "technology" and maybe with more tests will I think it should be allowed as evidence in a court of law.

Other than that it just a gimmick - we're talking about taking people's freedom here or sentencing them to death.