Computational photography refers to image capture and processing techniques that aim to enhance upon optical processes absent from camera gear, a field that has grown substantially, especially for smartphone engineering. When clicking the shutter on your phone, you might think that the image captured was exactly what you saw, but nothing is further from the truth.
This data requires heavy interpretation, and with the hardware restrictions on smartphones as well as the limitations dictated by the laws of Physics, the actual raw image received by a sensor can look like a colourful mess. A lot of colour-science and image-processing sits in between the sensor and what you see on screen. These problems are compounded for specific uses like astrophotography, where light from the heavens is faint and barely detectable by small sensors.
The Institute of Space Sciences and Astronomy of the University of Malta, in a project funded by the MCST Research Excellence Fund, has worked on the OPTICA project (OPtical Telescope Intelligence for Computational Astrophotography) to build software that allows for good astrophotography from small sensors in smartphones.
The OPTICA team is now currently researching ways to remove a tripod from the equation altogether
The dynamics of astrophotography have barely changed since their inception. Astrophotography requires long exposures for enough light from distant stars to reach the sensor. Furthermore, many of these frames are needed to enhance the final image, and this requires specialised software that can cancel effects of the earth’s rotation during this time window. Smartphone makers have started automating various ‘night-mode’ photo captures, allowing casual photographers a go at capturing the night sky.
OPTICA enhanced this process substantially, by making use of tailor-made artificial-intelligence algorithms that can track the sky without a sky tracker, stack images without external software, and fixing for small sensor noise levels and optical defects. So far, excellent results off a casual tripod stand can be obtained, far exceeding night-mode results with sharper, cleaner and far more detailed images. The OPTICA team is now currently researching ways to remove a tripod from the equation altogether, for anytime, anywhere astrophotography from mobile phones. The key is to leverage the powerful computing power on modern smartphone chips.
Over the next years, it will be increasingly difficult to define what a camera is. The main physical components remain the lens and sensor. But even professional cameras are moving into heavier computational processing. A camera is nowadays a hardware-software package, with intelligent software taking over some of the creative decisions and working for us.
Andrea DeMarco is a senior lecturer at the Institute of Space Sciences and Astronomy, University of Malta.
Sound Bites
• Comet C/2022 E3 ZTF will remain visible in evening skies close to Mars during this week. The so-called green comet will remain visible, albeit dimming slowly as it recedes away, located close to Mars in our evening skies throughout the coming week.
DID YOU KNOW?
• There are billions of stars in our galaxy. When looking at the Milky Way, the haze of milky white observable from dark sky locations is actually the combined light of millions of stars, with the core of the galaxy being some 26,000 light years away.
• The nearest star, Proxima Centauri, is roughly 4.2 light years away. Notwithstanding this, Proxima Centauri is a faint red dwarf, visible only via a telescope.
• There are parts of our galaxy which we never see from Malta. Due to our latitudinal position, there are some parts of our galaxy that are forever below the horizon from Malta. However, going farther south in latitude, more of the galaxy can be seen.