Carl Haber’s IRENE—Reconstructing Audio with Imaging Technology

Sometimes the coolness factor of a new technology just overwhelms me and I jump it to the front of the queue. Even with NI Week approaching and all the new technologies at play, I just had to post on Carl Haber’s work using imaging technology to reconstruct audio from old phonograph records. In the Smithsonian and other museums around the world are thousands of old lacquer-plated records with skips, scratches and other defects marring the sound, not to mention the obsolete nature of the equipment used to play them. Carl came up with a vision system that images the LP record and “unrolls” the grooves into a long, unbroken string which his software (called IRENE for Image, Reconstruct, Erase Noise, etc) converts into audio components and even plays it out (minus the skips and scratches). The full story from NPR is here.

Carl’s work comes from particle physics which you can read more about here. Given the strong need for such technology, libraries around the nation (such as the Library of Congress) are pulling him into discussions on implementing the technology.

The technology involves imaging the groove shape with precision optical metrology techniques and then applying digital filtering. For flat records, 2D imaging is sufficient. For Edison-era cylinders, 3D imaging is needed. IRENE images the groove using color coded confocal microscopy. Digital imaging of the groove is analogous to digital time sampling but with respect to the spatial direction. Thus, Nyquist comes into play. To reduce unwanted alias signals, IRENE applies a lowpass filter. Stages controlled by DC servo motors read by linear encoders were used to move the camera over the record.

The paper goes on to describe in great detail the motion/vision control of the system to image a cylinder and account for azimuth changes across the cylinder and the signal processing used to reconstruct the waveforms generated by the imaging system.

Best regards,
Hall T.

The New Telemarketer – Magazine Subscription Promoters

I noticed the other day that I rarely receive calls at home any more from telemarketers aside from my university alma mater and a few charity organizations. Telemarketers had demonstrated such egregious behavior that they actually incited Congress to pass a law allowing people to opt-out. Getting anything through Congress is well . . . an Act of Congress – a very substantial undertaking. The telemarketing industry took a hit for it.

While I no longer receive many calls at home, I notice that a call coming to me through the company’s direct line is a call I don’t want to take – it’s what I consider to be the ‘New Telemarketer’. The call begins with

Caller: “Is Mr. Martin there?”

Me: “Yes”

Caller: “How are you doing today, sir?”

Me: “Fine”

Caller: “I’m offering you a free subscription to our magazine. All I need to do is verify your address and ask a few questions.”

And so it goes. I’ve often wondered how print magazines are getting along these days now that the Web is the media of choice – especially for engineers. The fact that they are calling to beg me to take their magazine (free of charge) tells me they are not doing that well.

Until we get another act of Congress to create an opt-out list for magazine subscription promoters, I’ve learned to manage the situation somewhat. In the current situation, when I suspect it’s a magazine subscriber the call goes as follows:

Caller: “Is Mr. Martin there?”

Me: “Hello”

Caller: “Are you Mr. Martin?”

Me: “I’m afraid he’s not here.”

Caller: Pause. “Do you know when he will return?”

Me: “In about two weeks.”

Caller: “I’ll call back later.”

It’s not exactly honest but it gets me off the hook for now. Where’s Congress when you need them?

Best regards,
Hall T.

Obligatory iPhone Posting

It appears I am the last blogger on planet earth to post about the iPhone. I tried to put it off as long as possible, but I am succumbing to peer pressure. I stopped in at the local Apple yesterday and had a chance to play with one. In looking at the phone the screen is the first thing that hits you. It’s gorgeous. My Nokia phone screen pales in comparison. You can actually surf the web with reasonable viewing. I would never surf the web with my Nokia phone. The second thing that hits you is the touch screen interface – no keys. Since I’m developing an early stage of carpal tunnel syndrome, I’m starting to justify my purchase decision based on medical conditions. I also found it interesting how the iPhone uses sensors to enhance the user experience. The device contains accelerometers to rotate the screen based on how the user holds it. There’s also an ambient light sensor and an infrared sensor. In this article the author describes other efforts to use sensors on handheld devices to improve a device’s usability.

Embedding sensors into devices has long been predicted and some have been tried, but the concept seems to be emerging into standard products now. Neil Gershenfeld’s book, When Things Start to Think outlines the use of sensors in clothing and other articles to make them more useful.

A project by Tanzeem Choudbury at Intel uses an accelerometer, a barometer, a humidity sensor, a thermometer, a light sensor, a digital compass, and a microphone to sense the users activity and social situation (home, office, crowded room) etc and make decisions based on the environment.

The iPhone is a game changer and as I wrote in my post last week I think it could be a valuable platform for virtual instrumentation. Screen navigation has improved that one can do fairly sophisticated programming on the device. Memory is large enough to support substantial features. Wireless connectivity allows the device to connect to hardware devices for control and data acquisition applications. The use of sensors can also leverage virtual instrumentation applications – detecting the ambient temperature, proximity, and other capabilities can make the device useful as a measurement tool all by itself.

In fact as devices continue to come out with sensors built-in, why not use virtual instrumentation to make use of those sensors for measurement and automation purposes?

Best regards,
Hall T.

It Seems Like Old Times—From PCs to Mobile Phones

Steve Jobs leads Apple to the top with the best technical & user friendly products. Bruce Willis is Dying Hard, and the stock market is rocketing upwards with the no limit in sight. Is this 2007? No, try 1987. Apple’s Macintosh computer tops the technical users’ wish list. Bruce Willis stars in the first Die Hard movie, and the upwardly mobile stock market continued to rise throughout the year until it crashed in October of 1987.

It seems like old times only this time Apple is innovating in the world of mobile phones and not PCs, by releasing a combination iPod, web-browser, and mobile phone—called the iPhone. It tops every technical user’s wish list and sets a new standard for technical ease of use and cool design. Bruce Willis is now in his fourth Die Hard movie. I haven’t seen the movie so I don’t know how much it has improved on the core theme of never, ever give up. The Dow has risen to over 13,000 points but still roller coasters with every news bit on oil prices, politics, employment figures, and more.

The more things change, the more they stay the same. It’s instructive to learn from the PC era and apply the rules to the current generation. In the PC-era, IBM developed the standard and everyone adhered to the core basics. It was hard to tell one vendor from another. The machines mostly looked alike and worked the same. It was generally difficult to use, but the PCs at that time had a few applications that drove sales – Lotus 1-2-3, WordPerfect word processing, and others.

Today, the mobile phone market looks strikingly similar. Most mobile phones look the same, and work the same way (e.g. text messaging). Vendors tout the differences in their solutions (better network coverage, more friendly service plans, etc.) but for the most part there’s little differentiation. The Apple iPhone combines key technologies (not necessarily Apples’ invention) into a user experience that takes it to the next level. One of the key inventions is the interface.

In the PC-era, virtual instrumentation made substantial use of the PC-platform (doubling in performance and halving in cost every 18 months) to build measurement solutions. Now that the platform of choice is the mobile phone, how could virtual instrumentation leverage this platform?

It’s been predicted since the post-millennium that “internet devices” would overtake the PC. The Palm appeared to be the “one” that would lead the charge, but in the end it turned out to be a “false pretender” in Ray Kurzweil’s nomenclature. It tried to morph into a leader with the Treo phone, but it didn’t quite make it there. The iPhone is the true leader.

Twenty years ago we called them, Personal Computers. Today we call them PCs. I guess when I write my next ‘déjà vu all over again’ post twenty years from now, I’ll call the mobile phones, MPs. Hopefully, between now and then virtual instrumentation will leverage the power of the mobile phone.

Best regards,
Hall T.