A Teleprompter For The Rest Of Us

Sometimes it’s so easy to become tied up in a world of microcontrollers and complex mechanical linkages that we forget the simplest of hacks can be the most elegant. [Lex Kravitz]’s teleprompter is a good example, delivering the measured style of a professional addressing the studio camera to the laptop owner with a built-in camera nestled above their screen.

Just because this teleprompter is simply a mirror and a piece of clear plastic doesn’t mean that it’s a poor quality implementation though. It’s housed in a smart two-piece 3D-printed frame that hooks over the top of the monitor and locates with an area of screen into which you can place your teleprompter software. This is a world into which we haven’t previously delved, so aside from the array of Windows freeware that pops up in a Google search we found there are a few opensource offerings. There is TeleKast which appears to be no longer updated, and Imaginary Teleprompter, which even has an online version you can try in a web browser.

[Lex] is no stranger to these pages, having most recently appeared as part of our PPE testing Hack Chat.

Background Substitution, No Green Screen Required

All this working from home that people have been doing has a natural but unintended consequence: revealing your dirty little domestic secrets on a video conference. Face time can come at a high price if the only room you have available for work is the bedroom, with piles of dirty laundry or perhaps the incriminating contents of one’s nightstand on full display for your coworkers.

There has to be a tech fix for this problem, and many of the commercial video conferencing platforms support virtual backgrounds. But [Florian Echtler] would rather air his dirty laundry than go near Zoom, so he built a machine-learning background substitution app that works with just about any video conferencing platform. Awkwardly dubbed DeepBackSub — he’s working on a better name — the system does the hard work of finding the person in the frame with Tensorflow Lite. After identifying everything in the frame that’s a person, OpenCV replaces everything that’s not with whatever you choose, and the modified scene is piped over a virtual video device to the videoconferencing software. He’s tested on Firefox, Skype, and guvcview so far, all running on Linux. The resolution and framerates are limited, but such is the cost of keeping your secrets and establishing a firm boundary between work life and home life.

[Florian] has taken the need for a green screen out of what’s formally known as chroma key compositing, which [Tom Scott] did a great primer on a few years back. A physical green screen is the traditional way to do this, but we honestly think this technique is great and can’t wait to try it out with our Hackaday colleagues at the weekly videoconference.