Tuesday, October 28, 2008

Image Recognition: Military requirements push technology forward

The Strategy Page has an article about how the proliferation of video on the battlefield (e.g. from surveillance cameras and even night vision goggles) is driving technology development. Initially, it was the UK (United Kingdom) that drove image recognition technology with its massive deployment of CCTV in public spaces (e.g. train stations, airports, city centers, and shopping malls). Now, it is the military.

The benefit from computer-assistance in analyzing video comes from the following:

  1. Volume (i.e. the sheer number of cameras and, hence, images to be monitored and/or analyzed)
  2. Concentration (i.e. the human visual system loses the ability to concentrate effectively on images after about 20 minutes of continuous viewing)
  3. Memory (i.e. computers can track and, possibly, predict more things simultaneously than a human can because, generally speaking, computers are not nearly as attention and working-memory limited in the short-term as humans and far outstrip us in their ability to recall video sequences over the long term - they can just play back the video recording off of their hard disks)

The article claims that the abilities of computer systems to recognize patterns is rapidly improving and approaching that of humans - that is no small feat as humans are simply amazing in their ability to perform real-time pattern analysis.

One intriguing point made in the article is that the current conflicts are generating a lot of real-world recordings of "bad behavior" that can be used to train and test new pattern analysis and prediction algorithms - training data like this is like gold to us signal processing types!


Thursday, October 09, 2008

Human Auditory System: Artificial Cochlea

A next generation implementation of an artificial cochlea has been developed by researchers at the University of Michigan and Tufts University (both in the USA). The natural cochlea is the sea-shell-shaped structure in the human auditory system that is the final stage in the conversion of air pressure variations (a.k.a. sound waves) into neural impulses that convey the frequency and amplitude information information contained in the sound to the brain for interpretation.

EDN (USA technical magazine) has an article which contains more technical detail and pictures on the advance.

I should point out that this version of the artificial cochlea is not an exact replica in form factor (i.e. shape) or function of a natural cochlea. For instance, the artificial cochlea is planar in shape versus sea-shell-shaped; covers the frequency range of 4200 to 35,000 Hz versus the 20 to 20,000 Hz of the human ear; and isn't continually fine tuned by an external processor to focus on frequency bands of interest, like the human cochlea does when one is, for instance, one's brain is picking out a familiar voice in a cocktail party situation. I mention this not to detract from their excellent work, but instead to give you, curious reader, reasonable expectations as to its specifications and performance.