The selfie has become a cultural symbol of mobile phones. But this fun pastime has been made possible because of path-breaking engineering inventions in digital image sensors.

The inventors – Eric Fossum (USA), George Smith (USA), Nobukazu Teranishi (Japan) and Michael Tompsett (UK) – were awarded the 2017 £1 million Queen Elizabeth Prize for Engineering for revolutionising the way images are captured and analysed.

The technology has "dramatically changed the way we communicate, enabling us to share information instantaneously and communicate around the world in real-time, even on our phones,” say the prize’s judges (of which I was one).

The transformational impact of the technology has been felt most in emerging regions of the world, including in Africa, where visual communication was limited by the high equipment costs, complex imaging processing needs and requirement for specialised expertise.

The first major impact of the technology on African users was to expand global connectivity by making it possible for the youth to access information that was collected using the technology via the Internet.

African engineers have been able to use such information to design their own technologies suited to local condition. In 2016 Arthur Zhang, a young Cameroonian medical engineering was awarded the $37,000 Africa Prize for Engineering Innovation by the UK Royal Academy of Engineering. Zhang invented the Cardiopad, a tablet computer takes heart readings and sends them to a heart specialist using the Internet.

Zhang was trained in electronic engineering but gained much of the relevant medical knowledge by watching video online, many of which had been posted using digital camera. Many more young Africans are following in Zhang footprints in using such material to acquire knowledge that is available through their regular university courses.

Organizations such as the Khan Academy are now providing free education content to students and teachers across Africa at all grades in a variety of fields such as math, science and engineering, computing, arts and humanities, and economics and finance. Much of the material has been uploaded online using low-cost digital cameras.

Video, especially using free platforms such as Skype, has flattened Africa’s communication world and expanded global exchanges. The dramatic reduction in the cost of video communication was made possible through the path-breaking creation of "high-speed, low-cost color imaging at a resolution and sensitivity that can exceed that of the human eye,” as noted by the prize judges.

The adoption of mobile phones has expanded everyday Africans’ ability to share important life-changing events with the rest of the world. Real-time images of political demonstrations in Tahrir Square in Cairo galvanised global focus on autocracy in the region. Instant sharing of images of violation of human rights in various African countries has helped to shine a global spotlight on the need to expand human liberties on the continent. Corrupt dealings and acts of oppression are captured on camera and shared with the rest of the world.

Worldwide, "image sensor technology has transformed medical treatments, science, personal communication and entertainment – from Skyping, selfies, computer games and feature length digital movies – to reporting live from wars using the small camera on a smartphone,” say the prize judges. In addition, it "saves lives, by using non-surgical pill cameras and endoscopes inside our bodies to diagnose medical problems, as well as helping to reduce X-ray doses to patients and improving dental care.”

For these reasons smartphones, which are being rapidly adopted in Africa, provide a low-cost infrastructure for technological innovation. It provides opportunities for young African engineers to leverage the technology for solving local problems in all fields of human endeavor.

In agriculture, farmers can now take images of the diseased leaves of their crops and share them with scientists around the world for identification and advice. Such digital imaging research is an important addition to other agricultural use of mobile phones that constitute low-cost extension approaches.

Young African engineers are making extensive use of mobile phones for disease diagnosis. Ugandan researchers developed a jacket that diagnoses pneumonia faster than the standard methods used by doctors. Imaging technologies offer additional ways to expand the range of diagnosis for a wide range of diseases.

In low-cost eye care, for example, EyeNetra uses smartphones as a platform to capture the refractive power of the lenses in eyeglasses. EyeNetra is planning to deploy its technology in Nigeria. It has distributed units to be piloted in Gabon, Gambia, Kenya, Morocco, Rwanda, South Africa and Zimbabwe.

There have been concerns that the emerging era of personalised medicine will create a "health divide” between the industrialised and emerging worlds. This is mainly because of human genetic diversity influences the choice of treatment options. Smartphones are becoming as a low-cost way to pre-empt the emergence of such a divide.

Climate change is going to force African scientists to study afresh alternations in the microscopic world. With as little as $15 Micro Phone Lens it will soon be possible to turn a regular smartphone into a microscope that capture images and videos at a magnification range of 15-60 times using the phone’s digital zoom feature. The add-on will inspire a new generation of explorers and scientists.

This technology is putting in the hands of young Africans new engineering capabilities to capture, store and share images. It will help the continent to radically transform its ability to communicate, share ideas, and acquire new knowledge from around the world. Much of this can now be done at almost zero cost. It gives Africa new possibilities to re-image its future through the lens of creativity and innovation.

Professor Calestous Juma is Professor of the Practice of International Development at Harvard Kennedy School and a judge of the Queen Elizabeth Prize for Engineering and co-chairs the African High-Level Panel on Emerging Technologies of the African Union. He is author of Innovation and Its Enemies: Why People Resist New Technology.