Thursday, January 31, 2008

Optics: How camera lenses are made

YouTube has a fascinating video segment on how camera lenses are made.

(Hat tip: Gizmodo)

Acoustics: Underwater acoustic modem

An Israeli start-up, Sea-Eye Underwater Ltd., has developed an underwater acoustic modem that is fast enough to transmit real-time video. The reported range of the modem is 100-200 meters (1 meter = 1 yard, approximately).

EETimes has the story.

Monday, January 21, 2008

Image Forensics: An overview

I recently purchased and read the excellent book, Photoshop CS3 for Forensic Professionals, by George Reis and can highly recommend it. Today I came across an overview of image forensics written by him and thought I'd share it with you. The overview article, in an issue of MacTech, can be found here. Enjoy!

Sunday, January 20, 2008

Forensics: Name that codec in one note

Sometimes I feel that I lose track of the founding purpose of this blog - which is to educate people in a non-commercial way about audio and video forensics. In that spirit, I will let the non-specialists among you in on a current trick of the trade - namely, G-Spot. G-Spot is often the first thing a video forensics professional turns to when a piece of digital surveillance video evidence won't play on the laboratory's workstation.

G-Spot is a software application developed by Steve Greengerg to identify what codec is needed to play a video file. Given the plethora of low-cost digital video recorder (DVR) security systems on the market, many, if not most, with their own proprietary codecs, G-Spot can be a life saver. Here is a link to a review of the application (Note: there is some sexual innuendo, but I did not find it to be overly crude).

Now you know what drives many video examiners to distraction every day and what they turn to for the answer.

Brain Science: Train your brain for multi-tasking

As reported by John Tierney of the New York Times (center-left news media, USA), researchers at Wake Forest University and University of North Carolina Greensboro (both in the USA), there may be something to the "Train your brain" fad, at least if you are musical conductor:

The researchers used functional magnetic resonance imaging to map the brains of musical conductors and non-musicians who tried to distinguish musical tones while also being shown visual images. The scans showed that non-musicians had to turn off more of their visual sense than the conductors did in order to focus on the task. One of the researchers, Dr. Hodges, director of the Music Research Institute at UNC-Greensboro, says there are two possible interpretations of the results:

One is that the brains of musicians are wired this way, and that’s why they became musicians. The other is that they train their brains for rewiring. Because conductors have to be able to hear a bad note, then identify who did it, perhaps they rewire their brains to combine their visual and auditory senses. An experienced conductor has trained day after day, year after year, to let their brains pick up various signals from their senses.

The article is quite good and highly worth reading through.

Thursday, January 10, 2008

Miscellaneous: List of links Part 2

How the brain makes a whole out of parts

Humans ARE actually better with one sense than most mammals (namely, fine sound frequency sensitivity)

Adobe Photoshop Elements 6 for Mac is about to be released (and it includes some very neat features for a consumer-grade product, such as Guided Editing and Photomerge)

Telephone companies cancel FBI wire taps over unpaid bills (Not to be a cynic and nothing in particular against The Register, other news outlets, or governmental bodies, but don't be surprised if this hasn't been overblown a bit for political or news making purposes.)

LANL researchers develop low power MRI system (LANL = Los Alamos National Laboratory, USA)

Miscellaneous - List of links for audio geeks

Too much work PLUS too few mentally productive hours EQUALS a list of links without any in-depth analysis. Sorry about that, but I hope to return to blogging more seriously soon. Until then, enjoy these:

Stereo from a single box (Blumlein was an audio genius. If you are an audiophile, I suggest you read a biography on him sometime.)

How the iPhone blew up the wireless industry

Acoustic superlens could mean finer ultrasound scans

Ultra-thin digital voice recorder

Noise reduction technology for cell/mobile phones
(Note that the sales spiel uses words like "crystal" and "pristine" but you can clearly hear artifacting at low levels. Not trying to be overly critical, but couldn't they have let the results speak for themselves without the spin?)