Tricking The Brain Into Seeing Boosted Contrast In Stereo Imagery

February 1, 2020 by 20 Comments

Last year a team of researchers published a paper detailing a method of boosting visual contrast and image quality in stereoscopic displays. The method is called Dichoptic Contrast Enhancement (DiCE) and works by showing each eye a slightly different version of an image, tricking the brain into fusing the two views together in a way that boosts perceived image quality. This only works on stereoscopic displays like VR headsets, but it’s computationally simple and easily implemented. This trick could be used to offset some of the limitations of displays used in headsets, for example making them appear capable of deeper contrast levels than they can physically deliver. This is good, because higher contrasts are generally perceived as being more realistic and three-dimensional; important factors in VR headsets and other stereoscopic displays.

Stereoscopic vision works by having the brain fuse together what both eyes see, and this process is called binocular fusion. The small differences between what each eye sees mostly conveys a sense of depth to us, but DiCE uses some of the quirks of binocular fusion to trick the brain into perceiving enhanced contrast in the visuals. This perceived higher contrast in turn leads to a stronger sense of depth and overall image quality.

Example of DiCE-processed images, showing each eye a different dynamic contrast range. The result is greater perceived contrast and image quality when the brain fuses the two together.

To pull off this trick, DiCE displays a different contrast level to both eyes in a way designed to encourage the brain to fuse them together in a positive way. In short, using a separate and different dynamic contrast range for each eye yields an overall greater perceived contrast range in the fused image. That’s simple in theory, but in practice there were a number of problems to solve. Chief among them was the fact that if the difference between what each eyes sees is too great, the result is discomfort due to binocular rivalry. The hard scientific work behind DiCE came from experimentally determining sweet spots, and pre-computing filters independent of viewer and content so that it could be applied in real-time for a consistent result.

Things like this are reminders that we experience the world only through the filter of our senses, and our perception of reality has quirks that can be demonstrated by things like this project and other “sensory fusion” edge cases like the Thermal Grill Illusion, which we saw used as the basis for a replica of the Pain Box from Dune.

A short video overview of the method is embedded below, and a PDF of the publication can be downloaded for further reading. Want a more hands-on approach? The team even made a DiCE plugin (freely) available from the Unity asset store.

Continue reading “Tricking The Brain Into Seeing Boosted Contrast In Stereo Imagery” →

CNC Hot-Wire Cutter Gives Form To Foam

February 1, 2020 by 12 Comments

Rapid prototyping tools are sometimes the difference between a project getting off the ground and one that stays strictly on paper. A lightweight, easy-to-form material is often all that’s needed to visualize a design and make a quick judgment on how to proceed. Polymeric foams excel in such applications, and a CNC hot-wire foam cutter is a tool that makes dealing with them quick and easy.

We’re used to seeing CNC machines where a lot of time and expense are put into making the frame as strong and rigid as possible. But [HowToMechatronics] knew that the polystyrene foam blocks he’d be using would easily yield to a hot nichrome wire, minimizing the cutting forces and the need for a stout frame. But the aluminum extrusions, 3D-printed connectors. and linear bearings he used still make for a frame stiff enough to give clean, accurate cuts. The addition of a turntable to the bed is a nice touch, turning the tool into a 2.5D machine. The video below details the construction and goes into depth on the toolchain [HowToMechatronics] used to go from design to G-code, including the tricks he used for making a continuous path, as well as integrating the turntable to make three-dimensional designs.

Plenty of hot-wire foam cutters have graced our pages before, everything from tiny hand-held cutters to a hot-wire “table saw” for foam. We like the effort put into this one, though, and the possibilities it opens up.

Continue reading “CNC Hot-Wire Cutter Gives Form To Foam” →

What Everyone Else Did With Eight Bits, The Germans Did With Only One

February 1, 2020 by 51 Comments

In the 1980s there was an impetus for the first time for young people to be equipped with computer literacy. A variety of different educational programmes were launched, typically involving a collaboration between a computer manufacturer and a broadcaster, and featuring BASIC programming on one of the 8-bit home computers of the day. One such educational scheme was a bit different though, the German broadcaster WDR produced an educational series using a modular computer featuring an unusual 1-bit processor that was programmed in hexadecimal machine code. [Jens Christian Restemeier] has produced a replica of this machine, that is as close to the original as he can make it. (Video, in German, embedded below.)

The computer is called the WDR-1, and had its origin in a kit machine before it was taken up by the broadcaster. The unusual 1-bit processor is a Motorola MC14500, which was produced from 1977 onwards for industrial control applications. He takes the viewer in the video below the break through the machine’s parts, explaining the purpose of each daughter card and the motherboard. Lacking an original to copy he instead worked from photographs to replicate the chip placements of the original, substituting pin headers for the unusual sockets used on the 1980s machines. Take a look at his video, below the break.

More information on the WDR-1 can be found online in German (Google translate link). Meanwhile we’ve featured the MC14500 before, in a small embedded computer.

Continue reading “What Everyone Else Did With Eight Bits, The Germans Did With Only One” →

See-Through Catalytic Converter

February 1, 2020 by 16 Comments

There’s always something to be learned from taking things apart. Sometimes the parts can be used for other things, sometimes they can be repaired or improved upon, but sometimes it’s all in good fun. Especially in this case where extremely high temperatures and combustible gasses are involved. This is from the latest video from [Warped Perception] that lets us see inside of a catalytic converter as its operating.

Catalytic converters are installed on most vehicles (and other internal combustion engines) in order to process unburned hydrocarbons from exhaust gasses with a catalyst. These can get extremely hot, and this high temperature complicated the build somewhat. There were two prototypes constructed for this build and the first was a cross-section of a catalytic converter with a glass window sealed on in order to allow the viewing of the catalyst during the operation of a small engine. It was easy to see the dirty exhaust gasses entering and cleaner gasses leaving, but the window eventually blew off. The second was a complete glass tube which worked much better until the fitting on the back finally failed.

A catalytic converter isn’t something we’d normally get to see the inside of, and this video was worth watching just to see one in operation in real life. You could also learn a thing or two about high-temperature fittings as well if you’re so inclined. It might be a nice pairing with another build we’ve seen which gave us a window into a different type of combustion chamber than ones normally found on combustion engines.

Thanks to [Ryoku] for the tip!

Continue reading “See-Through Catalytic Converter” →

A Nano With An Otter’s Bite

February 1, 2020 by 22 Comments

The would-be microcontroller experimenter is now faced with a bewildering array of choices when it comes to a tiny development board for their projects. Everything from descendants and clones of the original Arduino through to full-fat Linux powerhouses such as the Raspberry Pi Zero and similar boards can be had, and often for a reasonable price.

A new entrant has now joined the fray, the OtterPill is an STM32F072-based board with an Arduino-Nano-like pinout, and it comes from the bench of [Jana Marie]. With so many competitors you might ask yourself what it can offer, and it would be a valid point given that a Nano clone can be had for relative pennies. Aside from the Nano shield compatibility and extra power of the ARM Cortex M0 then, it’s an open source development board with USB-PD included from its USB-C socket, and with some elite BoM wizardry she’s managed to get the cost of its components to below three dollars. A USB-PD example firmware is available and a blank firmware is on its way. For now the board exists only in prototype form, but she’s putting together a production run if you would like one too. We saw an early development of it at eth0 back in the autumn, and given the progress since then we’re sure that we won’t have to wait for long.

Regular readers will recognise [Jana Marie]’s work, because otter-themed boards have made their way to these pages before. Our most recent ones were the USB-C replacement board bringing USB-PD to the TS-100 soldering iron, and  a nifty little USB board for addressable LEDs.

An Arcade Cabinet With Displays To Spare

January 31, 2020 by 15 Comments

We’ve all got a pretty good mental image of what an arcade cabinet looks like, so you probably don’t need to be reminded that traditionally they are single-screen affairs. But that idea dates back to when they were built around big and bulky CRT displays. Now that we have modern LCD, LED, and OLED panels, who says you have to follow the old rules?

That’s precisely the sort of out of the box thinking that lead [Al Linke] to build this unique multi-display arcade cabinet. The game itself is still played on a single screen, but several smaller sub-displays are dotted all around the cabinet to indicate various bits of ancillary information. Are they necessary? Hardly. But we can’t deny it’s a clever idea, and we wouldn’t be surprised if we start seeing something similar in other DIY cabinets.

The build started with a commercially available cabinet from Arcade1Up, which at this point are popular enough that some of the Big Box retailers have them in stock. All of the electronics except for the display were stripped out, and replaced with a Dell OptiPlex 9020 computer and high-quality joysticks and buttons. [Al] then installed his various displays all over the cabinet, including a gorgeous LED marquee that we’ve featured previously.

So what do all these little screens do? [Al] explains them in the video after the break, but the general idea is that they provide contextual information about the game you currently have loaded up. A two-color OLED display shows the name of the game and what it’s rated, while a seven segment LED display shows the year the game was released. The displays are located both by the controls and where you’d expect the coin slot to be, so whether you’re actively playing or across the room, you can see all the information.

We’re always amazed to see how builders find ways to make their own personal arcade cabinets stand out. While it’s an idea that at this point we’ve seen quite a lot of, no two projects have ever been quite the same.

Continue reading “An Arcade Cabinet With Displays To Spare” →

A 60 GHz Phased Array

January 31, 2020 by 15 Comments

Our friend [Hunter Scott] gave a talk at a past Supercon about phased array antennas. He mentioned he was looking for collaborators to create an antenna with the SiBeam SB9210 chip. This is a specialized chip for WirelessHD, a more or less failed video streaming protocol, and it’s essentially an entire 60 GHz phased array on a chip with both transmit and receive capabilities. For $15, it seems like quite the bargain, and [Hunter] still wants to put the device to work.

The downside is that Lattice bought SiBeam and killed this chip — not surprising considering WirelessHD never really took off. However, [Hunter] says the chip was in some old smart TVs and laptops. If you can find replacement boards for those devices on the surplus market, you can get the chip and the supporting circuitry for a song.

Continue reading “A 60 GHz Phased Array” →