If you’ve ever tried to get that perfect shot of a race car, athlete, wild animal, or any other fast-moving subject, you know how hard it can be - what are the odds that you’ll hit the shutter release button at just the right instant? You could try videotaping it and grabbing a still afterward, but chances are it will be grainy and blurry. It’s a common problem, but it might have just been solved. Medical researchers have developed a digital photographic technique that allows users to simultaneously shoot high-speed (slow motion) video and high-resolution stills, via the same sensor on the same camera.
The technology, called Temporal Pixel Multiplexing (TPM) was developed by scientists at the University of Oxford. They wanted a better way of imaging the rapid changes in light intensity of fluorescent molecules, inside heart cells. The scientists built their system using off-the-shelf components of digital cameras and projectors, for a fraction of the price of the equipment currently needed for similar results.
On a traditional digital camera, all of the pixels on the sensor chip, all at once, combine to form one still snapshot per exposure. With TPM, the pixels get divided up into evenly-distributed groups, each group sequentially taking its own usable snapshot, per exposure. Users can then combine the different groups’ lower-resolution sub-snapshots into one high-resolution snapshot, or play them in sequence as high-speed video footage. If the pixels were divided into 16 groups, for instance, then every exposure would potentially yield both one high-res snapshot created from 16 combined sub-snapshots, and 16 frames of moving video.
If that 16-group example was incorporated into a video camera shooting at 30 frames per second, then each second of that video footage would contain 30 high-resolution still images, and 480 consecutive frames of high-speed video. Presumably, users could then choose between watching their footage in lower-resolution slow motion, or high-resolution regular motion.
The technology has been patented by Isis Innovation, the University of Oxford's technology transfer office. There is already interest from outside parties in developing the technology for other scientific uses, for applications such as security systems and manufacturing control, and for consumer cameras.
All images are from the article Temporal pixel multiplexing for simultaneous high-speed, high-resolution imaging, at Nature Methods.