Blind Camera: Visualizing A Scene From Its Sounds Alone

A visualization by the Blind Camera based on recorded sounds and the training data set for the neural network. (Credit: Diego Trujillo Pisanty)
A visualization by the Blind Camera based on recorded sounds and the training data set for the neural network. (Credit: Diego Trujillo Pisanty)

When we see a photograph or photo of a scene, we can likely imagine what sounds would go with it, but what if this gets inverted, and we have to imagine the scene that goes with the sounds? How close would we get to reconstructing the scene in our mind, without the biases of our upbringing and background rendering this into a near-impossible task? This is essentially the focus of a project by [Diego Trujillo Pisanty] which he calls Blind Camera.

Based on video data recorded in Mexico City, a neural network created using Tensorflow 3 was trained using an RTX 3080 GPU on a dataset containing frames from these videos that were associated with a sound. As a result, when the thus trained neural network is presented with a sound profile (the ‘photo’), it’ll attempt to reconstruct the scene based on this input and its model, all of which has been adapted to run on a single Raspberry Pi 3B board.

However, since all the model knows are the sights and sounds of Mexico City, the resulting image will always be presented as a composite of scenes from this city. As [Diego] himself puts it: for the device, everything is a city. In a way it is an excellent way to demonstrate how not only neural networks are limited by their training data, but so too are us humans.

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A Ride-On Picnic Table For Those Idylic Summer Evenings

For most outsiders the Netherlands is a country of picturesque cities, windmills, tulips, and maybe those famous coffee shops. Head away from the coast though and you enter the country’s rural hinterland, farming country with lush green fields, dairy cattle, and farm lads doing what they do best, which is hacking old machinery to do crazy things under those wide skies. [Plodno] are based on a farm somewhere in the eastern Netherlands, and the latest of these lads’ creations is a motorised picnic table (Dutch language, you’ll need YouTube translated subtitles).

This is farm hacking at its best, with a scrap FIAT hatchback donating its running gear to a welded tubular frame, with a chain drive to a small single-cylinder engine. There’s no suspension save for the air in the tyres, the steering column is vertical, and the brake is a single inboard disk on the rear axle. Perhaps it’s fortunate that the intended beating heart, a Kawasaki motorycle engine, was misfiring, as it would have been truly lethal with that much power. We’re not too convinced at the legality of taking such a contraption on the public road in the Netherlands, but they seem to get away with it. Take a look at the build in the video below the break.

Here at Hackaday we like a good hacky farm build, even though sometimes they’re not so well-assembled.

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A 489 Megapixel Camera For Not A Lot

The megapixel wars of a decade ago saw cameras aggressively marketed on the resolution of their sensors, but as we progressed into the tens of megapixels it became obvious even to consumers that perhaps there might be a little more to the quality of a digital camera than just its resolution. Still, it’s a frontier that still has a way to go, even if [Yunus Zenichowski]’s 489 megapixel prototype is a bit of an outlier. As some of you may have guessed it’s a scanner camera, in which the sensor is a linear CCD that is mechanically traversed over the focal plane to capture the image line by line.

In the 3D printed shell are the guts of a cheap second-hand Canon scanner, and the lens comes from a projector. Both these components make it not only one of the highest resolution cameras we’ve ever brought you, but also by no means the most expensive. It’s definitely a work in progress and the results of a sensor designed for the controlled environment of a document scanner being used with real-world light leave something to be desired, but even with the slight imperfections of the projector lens it’s still a camera capable of some fascinating high-resolution photography. The files are all available, should you be interested, and you can see it in action in the video below the break.

It’s by no means the first scanner camera we’ve brought you, though some of the earlier projects now have dead links. It is however easily the one with the highest resolution.

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Passionate Hams Make Their Mark On The Hack Chat

Let’s be honest — there are some not very pleasant stereotypes associated with amateur radio, at least if you ask outsiders. Hams are often thought of as being in two camps: old guys who can’t figure out modern technology or conspiracy theorists who think their knowledge of radio will give them an edge after the world becomes a post-apocalyptic hellscape. We’ll leave it to you to decide which is the worse brush to be painted with.

As is often the case, the best way to fight such ignorance is with education and outreach. Events like our weekly Hack Chat are a perfect platform for that, as it allows the curious to ask questions and get answers directly from subject matter experts. This is precisely why we invited Mark Hughes and Beau Ambur to helm last week’s Chat. The fact that they’re both relatively recent licensees makes them uniquely qualified to shed some light on what it’s like to become part of the ham radio community in the 21st century. As an added bonus, they’re both sharp and articulate technologists — about as far as you can get from the mental image of the doddering old granddad who prefers the simplicity of the Morse key to those newfangled smarty-phones.

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High Voltage Ion Engines Take Trip On The High Seas

Over the last several months, we’ve been enjoying a front-row seat as [Jay Bowles] of Plasma Channel has been developing and perfecting his design for a high voltage multi-stage ionic thruster. With each installment, the unit has become smaller, lighter, and more powerful. Which is important, as the ultimate goal is to power an RC aircraft with them.

There’s still plenty of work to be done before [Jay] will be able to take his creation skyward, but he’s making all the right moves. As a step towards his goal, he recently teamed up with [RcTestFlight] to attach a pair of his thrusters — which have again been further tweaked and refined since we last saw them — to a custom catamaran hull. The result is a futuristic craft that skims across the water with no moving parts and no noise…if you don’t count the occasional stray arc from the 40,000 volts screaming through its experimental thrusters, anyway. Continue reading “High Voltage Ion Engines Take Trip On The High Seas”

Spy Tech: Unshredding Documents

Bureaucracies generate paper, usually lots of paper. Anything you consider private — especially anything that could get you in trouble — should go in a “burn box” which is usually a locked trash can that is periodically emptied into an incinerator. However, what about a paper shredder? Who hasn’t seen a movie or TV show where the office furiously shreds papers as the FBI, SEC, or some other three-letter-agency is trying to crash the door down?

That might have been the scene in the late 1980s when Germany reunified. The East German Ministry of State Security — known as the Stasi — had records of unlawful activity and, probably, information about people of interest. The staff made a best effort to destroy these records, but they did not quite complete their task.

The collapsing East German government ordered documents destroyed, and many were pulped or burned. However, many of the documents were shredded by hand, stuffed into bags, and were awaiting final destruction. There were also some documents destroyed by the interim government in 1990. Today there are about 16,000 of these bags remaining, each with 2,500 to 3,000 pieces of pages in them.

Machine-shredded documents were too small to recover, but the hand-shredded documents should be possible to reconstruct. After all, they do it all the time in spy movies, right? With modern computers and vision systems, it should be a snap.

You’d think so, anyway.

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Spaying Cats In One Shot

Feral cats live a rough life, and programs like Trap, Neuter, Release (TNR) attempt to keep their populations from exploding in a humane way. Researchers in Massachusetts have found a non-surgical way to spay cats that will help these efforts.

A single dose of anti-Müllerian hormone (AMH) gene therapy suppresses ovarian follicle formation, essentially turning off the ovulation cycle. After following the test cats for two years, none had kittens, unlike the cats in the control group. Other major hormones like estrogen were unaffected in the cats and they didn’t exhibit any negative side effects. The researchers said it will be some time before the treatment can be widely deployed, but it offers hope for helping our internet overlords and the environs they terrorize inhabit.

For those of you doing TNR work, you might want to try this trap alert system to let you know you’ve caught a cat for spaying or neutering. If you’d rather use a cat treat dispenser to motivate your code monkeys, then check out this hack.