Real-time Digital Puppetry

April 29, 2011 by Mike Nathan 4 Comments

digital_puppet_show

If it sometimes seems that there is only a finite amount of things you can do with your kids, have you ever considered making movies? We don’t mean taking home videos – we’re talking about making actual movies where your kids can orchestrate the action and be the indirect stars of the show.

Maker [Friedrich Kirchner] has been working on an application called MovieSandbox, which is an open-source realtime animation tool. A couple of years in the making, the project is cross-platform compatible on both Windows and Apple computers (with Linux in the works), making it accessible to just about everyone.

His most recent example of the software’s power is a simple digital puppet show, which is sure to please young and old alike. Using sock puppets fitted with special flex sensors, he is able to control his on-screen cartoon characters by simply moving his puppets’ “mouths”. An Arduino is used to pass the sensor data to his software, while also allowing him to dynamically switch camera angles with a series of buttons.

Obviously something like this requires a bit of configuration in advance, but given a bit of time we imagine it would be pretty easy to set up a digital puppet stage that will keep your kids happily occupied for hours on end.

Continue reading to see a quick video of his sock puppet theater in action.

[via Make]

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Tandy Color Computer (CoCo3) Color Video Playback

April 21, 2011 by Mike Szczys 18 Comments

[John W. Linville] wrote a digital video player for the Tandy Color Computer (aka TRS-80). The decades-old hardware performs quite well considering the limited resource he had to work with. This is the second iteration of his player, and can be seen after the break playing a promo video for CoCoFEST 2011 where he’ll show it off in person.

In the most recent thread post (at the time of writing) [John] shares the methods used to get this running. FFMPEG is used on a modern computer to process the source video by separating the audio into an 8-bit 11040Hz file, and it generates several PPM files with the proper video frame rate. ImageMagick takes it from there to convert the PPM files to a bitmap format. It also processes each frame for differential changes, reducing the size to fall within the available bandwidth. They are then interleaved with the audio to produce the final format. Video is 128×192 with rectangular pixels. [John’s] already used it to watch such classics as War Games on the antiquated hardware.

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Camera Software Learns To Pick You Out Of A Crowd

April 21, 2011 by Mike Nathan 42 Comments

tld_object_tracking

While the Kinect is great at tracking gross body movements and discerning what part of a person’s skeleton is moving in front of the camera, the device most definitely has its shortfalls. For instance, facial recognition is quite limited, and we’re guessing that it couldn’t easily track an individual’s eye throughout the room.

No, for tracking like that, you would need something far more robust. Under the guidance of [Krystian Mikolajczyk and Jiri Matas], PhD student [Zdenek Kalal] has been working on a piece of software called TLD, which has some pretty amazing capabilities. The software uses almost any computer-connected camera to simultaneously Track an object, Learn its appearance, and Detect the object whenever it appears in the video stream. The software is so effective as you can see in the video below, that it has been dubbed “Predator”.

Once he has chosen an object within the camera’s field of vision, the software monitors that object, learning more and more about how it looks under different conditions. The software’s learning abilities allow it to pick out individual facial features, follow moving objects in video, and can recognize an individual’s face amid a collection of others.

While the software can currently only track one object at a time, we imagine that with some additional development and computing horsepower, this technology will become even more amazing.

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Super Refined Kinect Physics Demo

April 13, 2011 by Mike Nathan 15 Comments

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Since the Kinect has become so popular among hackers, [Brad Simpson] over at IDEO Labs finally purchased one for their office and immediately got to tinkering. In about 2-3 hours time, he put together a pretty cool physics demo showing off some of the Kinect’s abilities.

Rather than using rough skeleton measurements like most hacks we have seen, he paid careful attention to the software side of things. Starting off using the Kinect’s full resolution (something not everybody does) [Brad] took the data and manipulated it quite a bit before creating the video embedded below. Skeleton data was collected and run through several iterations of a smoothing algorithm to substantially reduce the noise surrounding the resulting outline.

The final product is quite a bit different than the Kinect videos we are used to seeing, and it drastically improves how the user is able to interact with virtual objects added to the environment. As you may have noticed, the blocks that were added to the video ~~never~~ rarely penetrate the outline of the individual in the movie. This isn’t due to some sort of digital trickery – [Brad] was able to prevent the intersection of different objects via his tweaking of the Kinect data feed.

We’re not sure how much computing power this whole setup requires, but the code is available from their Google Code repository, so we hope to see other projects refined by utilizing the techniques shown off here.

[via KinectHacks]

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Oscilloscope Thinks It’s A Video Monitor

March 30, 2011 by Jeff Katz 13 Comments

There is nothing wrong with your television set. Do not attempt to adjust the picture.

Where would we be if we listened to advice like that? [Eric] writes that with a fairly simple circuit, he’s able to split a composite video signal into its constituent X and Y ramp signals for display on his trusty Tektronix 465m. A LM1881 IC does the bulk of the heavy lifting. After running the signal through a few passive components, the generated ramp signals are ready for consumption by his venerable ‘scope. All that’s needed past that is some additional glue logic to invert the levels so the image shows up properly. The end result is a display that has an almost ethereal quality to it, like an old TV set or something out of the movie Brazil.

Hit the break to catch a video of the circuit in action.

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Kinect Two-fer: MoCap Movie And Robot Control

March 26, 2011 by Mike Nathan 6 Comments

kinect_twofer

It’s no mystery that we like the Kinect around here, which is why we’re bringing you a Kinect two-fer today.

We have seen video hacks using the Kinect before, and this one ranks up there on the coolness scale. In [Torben’s] short film about an animation student nearly missing his assignment deadline, the Kinect was used to script the animation of a stick figure model. The animation was captured and built in Maya, then overlaid on a separate video clip to complete the movie. The overall quality is great, though you can notice some of the typical “jitter” that the Kinect is known for, and there are a few places where the model sinks into the floor a bit.

If you want to try your hand at animation using the Kinect, all of the scripts used to make the movie are available on the creator’s site for free. [via Kinect-Hacks]

Our second Kinect item comes in the form of a gesture driven Lego MindStorms bot. Using OpenNI along with Primesense for body tracking, [rasomuro] was able to use simple motions to drive his NXT bot around the house. His movements are tracked by the Kinect sensor which are translated into commands relayed to the robot via his laptop’s Bluetooth connection. Since the robot has two motors, he mapped couple of simple arm motions to drive the bot around. We’ll be honest when we say that the motions remind us of Will Farrell’s “Frank the Tank” scene in Old School, but [rasomuro] says that he is trying to simulate the use of levers to drive the bot. Either way, it’s pretty cool.

Videos of both hacks are embedded below for your perusal.

If you are interested in seeing some more cool Kinect hacks be sure to check out this Minecraft interface trio, this cool Kinect realtime video overlay, and this Kinect-Nerf gun video game interface.

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Video Experimenter Shield

March 24, 2011 by Kevin Dady 15 Comments

People always want to do more with less and the Video Experimenter Shield is no exception. Consisting of an LM1881 video sync separator, a handful of passive components, and a stylish PCB in the standard Arduino shield footprint.

The board features simple but useful controls and features, a removable jumper allows you to select a sync source, either from incoming video or the Arduino, a potentiometer to adjust the analog threshold, and there is a convenient signal breakout header.

Software is an enhanced version of the popular TV out library and allows you to start off with video graphics overlay, closed caption decoding, a simple gun game, and basic, but still effective frame capture, and computer vision. Of course, there are all sorts of other fun and amusing experiments that start to pop in mind once you check out a quick demo video after the break.

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