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: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.