Closeup of a film restorer's hand holding a 35mm film print to check for defects as it goes into a film scanner

35mm Film Restoration Process Explained

December 19, 2022 by 9 Comments

For a large part of the 20th century, motion pictures were distributed on nitrate film. Although cheaper for the studios, this film was highly flammable and prone to decay. On top of that, most film prints were simply discarded once they had been through their run at the cinema, so a lot of film history has been lost.

Sometimes, the rolls of projected film would be kept by the projectionist and eventually found by a collector. If the film was too badly damaged to project again, it might still get tossed. Pushing against this tide of decay and destruction are small groups of experts who scan and restore these films for the digital age.

still showing the difference in quality between a 16mm print of a 35mm animated movie and a new scan of the 35mm original
The quality difference between a smaller-format print and the original restored negative can be startling

The process is quite involved – starting with checking every single frame of film by hand and repairing any damaged perforations or splices that could come apart in the scanner. Each frame is then automatically scanned at up to 10K resolution to future-proof the process before being painstakingly digitally cleaned.

The real expertise is in knowing what is damage or dirt, and what is the character of the original film. Especially in stop-motion movies, the subtle changes between frames are really part of the original, so the automatic clean-up tools need to be selectively reined in so as not to lose the charm and art of the film-makers.

The results are quite astonishing and we all have teams like this to thank for protecting our cultural heritage.

If you’re interested in watching the process, then check out the video after the break. If you fancy a go at automatic film digitising yourself (preferably not on unique historical prints!) then we’ve shown projects to do just that in the past.

Thanks to [Cliff Claven] for the tip.

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Image-Generating AI Can Texture An Entire 3D Scene In Blender

December 18, 2022 by 26 Comments

[Carson Katri] has a fantastic solution to easily add textures to 3D scenes in Blender: have an image-generating AI create the texture on demand, and do it for you.

It’s not perfect — the odd door or window feature might suffer from a lack of right angles — but it’s pretty amazing.

As shown here, two featureless blocks on a featureless plain become run-down buildings by wrapping the 3D objects in a suitable image. It’s all done with the help of the Dream Textures add-on for Blender.

The solution uses Stable Diffusion to generate a texture for a scene based on a text prompt (e.g. “sci-fi abandoned buildings”), and leverages an understanding of a scene’s depth for best results. The AI-generated results aren’t always entirely perfect, but the process is pretty amazing. Not to mention fantastically fast compared to creating from scratch.

AI image generation capabilities are progressing at a breakneck pace, and giving people access to tools that can be run locally is what drives interesting and useful applications like this one here.

Curious to know more about how systems like Stable Diffusion work? Here’s a pretty good technical primer, and the Washington Post recently published a less-technical (but accurate) interactive article explaining how AI image generators work, as well as the impact they are having.

The display of a medical ultrasound scanner showing "HackedScan II"

Medical Ultrasound Scanner Gives Up Its Secrets, Runs DOOM

December 18, 2022 by 4 Comments

Medical equipment often makes for interesting teardown videos: the strict requirements imposed by certification bodies mean you’ll find good quality components and a high standard of design and manufacturing. But when [Buy It Fix It] bought an ultrasound scanner on eBay, he wasn’t interested in tearing it down: his plan was to use it to find out if his sheep are in lamb, so he went on to repair it and modify it for its new purpose.

The device in question is a Mediwatch Bardscan II, which is meant to be used for scanning people’s bladders. The mainboard has a completely different model number however, which suggests that the basic design is used for several types of ultrasound scanners. The system is powered by an AMD Geode processor that runs Windows XP Embedded stored on a CompactFlash card, so examining the internal software is easy: the scanner interface even runs on a regular Windows PC.

Several files on the internal drive point at hidden features, with filenames like kidney.dib and liver.dib indicating that the instrument can scan more than just bladders. The drive also holds several versions of the scanning app, as well as a .ini file in which lots of features can be enabled or disabled. By running the executable through x32dbg, [Buy It Fix It] was even able to recover the password to enable the “Advanced Settings” menu — it’s “u10” in case you were wondering.

With a bit of file editing, [Buy It Fix It] managed to turn the rather basic system into a way more flexible ultrasound scanner. For example, he can now adjust the scan depth, replay previous scans and make notes on top of any captured images. It can even run DOOM, as he demonstrates at the end of the video — though we can imagine his sheep might not enjoy the sight of their owner approaching them with a box full of flame-throwing demons.

Medical ultrasound scanners, which have been around for quite a while, may appear to be complex machines, but it is possible to make a simple version with easily available components.

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Robot Dog Has Animal Magnetism

December 18, 2022 by 7 Comments

Robot “dogs” are all the rage lately, but you probably haven’t seen one that can climb up a wall. Researchers in Korea have made one that can, assuming the wall is made out of a metal that a magnet can stick to at least. The robot, MARVEL or magnetically adhesive robot for versatile and expeditious locomotion, might be pressing its luck on acronyms, but it is pretty agile as you can see in the video below. Tests showed the robot walking on walls and ceilings. It can cross gaps and obstacles and can even handle a curved storage tank with paint and rust.

The robot weighs 8 kilograms (17.6 pounds), can carry 2 – 3 kg of payload, and operates without a tether. Each foot contains both an electropermanent magnet and magnetorheological elastomers. If you haven’t seen them before, an electropermanent magnet, or EPM, is a magnet that can be turned on or off electronically. The elastomer is a polymer containing ferromagnetic particles that can alter the material’s properties in response to a magnetic field.

EPMs have two parts. One part is a simple permanent magnet. The other is a soft core easily magnetized by a surrounding coil. If you magnetize the soft core to oppose the permanent magnet, the fields cancel out, effectively turning off the magnet. If you magnetize it the other way, it reinforces the field.

This is better than an electromagnet in this application because turning the magnet on or off only requires a brief pulse. If you want your robot to hang out on the ceiling with Spider Man indefinitely, you don’t have to worry about draining your batteries while keeping an electromagnet engaged.

Overall, an interesting robot. Most wall-climbing robots we’ve seen are pretty lightweight. We don’t see nearly as many that can have the feeling of clinging to the ceiling.

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A Binaural Microphone For The Great Outdoors

December 17, 2022 by 15 Comments

A binaural recording is designed to mimic as closely as possible the experience of listening through human ears, and thus binaural microphones are often shaped like the human head with the microphone cartridges placed where the ears would be. That’s not the only way to make a binaural microphone though, and the Crown Stereo Ambient Sampling System, or SASS, did the same thing with a pair of pressure zone microphones for outdoor recordings. [Filip Mulier] doesn’t have one of the originals, but he’s done his best to make a SASS-like microphone of his own.

The attractive thing about this design is its simplicity, making use of foam sheets for the main body, with packing board as a rain deflector and a couple of layers of non-woven cloth as a wind filter. Perhaps best of all though are the recordings, in which we hear ambient recording at its finest. Listen with headphones, we suggest the dawn chorus.

If binaural recording and stereo interests you, we’ve taken a closer look in the past.

Differential Swerve Drive Is Highly Maneuverable

December 17, 2022 by 17 Comments

There are a variety of wheel designs out there that can provide for rotation and translation in various directions. The differential swerve drive, though, as demonstrated by [WildWillyRobots], uses regular wheels on a complex mount to achieve impressive directional flexibility.

The design uses a regular round wheel mounted on an axle, which has a gear on one end. This allows the wheel to be driven. The wheel and axle is mounted upon a circular carrier, which is then fitted with a pair of surrounding gears on bearings. Differentially driving these gears changes the way the drive behaves. With both gears driven in the same direction, the wheel rotates on its vertical axis to point in different directions. If both gears are driven in opposite direction, the wheel itself is driven. Relatively varying the speed of both gears allows the direction and drive of the wheel to be controlled. The result is a wheel that can rotate to any angle, and then be driven forwards or backwards as well.

Fitting a set of these wheels to a robot creates a highly maneuverable platform. As a bonus, it doesn’t have the drawback of poor grip that is common with various omniwheel-type designs.

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Kids’ Jukebox Based On Arduino With RFID

December 16, 2022 by 10 Comments

Consumer electronics aimed at young children tend to be quite janky and cheap-looking, and they often have to be to survive the extreme stress-testing normal use in this situation. You could buy a higher quality item intended for normal use, but this carries the risk of burning a hole in the pockets of the parents. To thread the needle on this dilemma for a child’s audiobook player, [Turi] built the Grimmboy for a relative of his.

Taking its name from the Brothers Grimm, the player is able of playing a number of children’s stories and fables in multiple languages, with each physically represented by a small cassette tape likeness with an RFID tag hidden in each one. A tape can be selected and placed in the player, and the Arduino at the center of it will recognize the tag and play the corresponding MP3 file stored locally on an SD card. There are simple controls and all the circuitry to support its lithium battery as well. All of the source code that [Turi] used to build this is available on the project’s GitHub page.

This was also featured at the Arudino blog as well, and we actually featured a similar project a while ago with a slightly different spin. Both are based on ideas from Tonuino, an open source project aimed at turning Arduinos into MP3 players. If you’re looking to build something with a few more features, though, take a look at this custom build based on the RP2040 microcontroller instead.