Programmable Fresnel zone aperture camera is set to revolutionise imaging technology

Lensless imaging system – LIP – adapts mask in real time to enhance image resolution and quality

Cameras could see their traditional bulky lenses eliminated by a promising imaging alternative – the Fresnel zone aperture, or lensless imaging – camera. It employs a lightweight patterned mask which modulates incoming light onto the image detection sensor, incorporated with computational reconstruction of the image. Existing lensless systems use fixed masks that can result in aliasing artifacts and unstable reconstructions when conditions are non-ideal which constrains image quality and versatility of uses.

A research team led by Professor Chao Zuo from the Smart Computational Imaging Laboratory (SCILab), Nanjing University of Science and Technology, in Xuanwu, Nanjing, Jiangsu, China, has developed a programmable lensless imaging system based on a variable Fresnel zone aperture (FZA) displayed on an LCD screen.

In this study, they introduce a new imaging framework called LIP – lensless imaging with a programmable FZA – which does not rely on a static pattern. The LIP system dynamically adjusts the mask in real time to capture richer information across multiple dimensions. These measurements are then resolved algorithmically to rebuild into high-resolution images with an enhanced signal-to-noise ratio (SNR).

 “This space-frequency joint framework supports adaptive switching of encoding strategies for static or dynamic scenes, enabling real-time imaging with both high resolution and frame rate,” said Professor Zuo.

With a miniaturised prototype – small enough to hold in your hand – and developed in-house by the research team, they conducted a series of experiments to evaluate its performance. When compared to conventional static-modulation lensless imaging methods, the LIP demonstrated an improvement of 250% in spatial resolution and a 3 dB enhancement in SNR.

In dynamic gesture recognition experiments – including actions such as tapping, zooming, and rotating – the LIP system maintained real-time reconstruction at 15 frames per second, while being nearly 90% smaller than traditional gesture-sensing devices.

“LIP is poised for broader impact through integration with emerging technologies such as intelligent algorithms, novel spatial light modulators and advanced microfabrication,” Professor Zuo suggests could be the impact of this imaging system. 

One potential application is multi-modal sensing, where LIP is integrated with polarisation, depth, or spectral modalities to provide richer optical information for biomedical imaging and material analysis.

Additionally, the LIP system could have applications where portability is needed which are compact and lightweight such as for wearable devices, augmented reality, virtual reality and on mobile platforms.

“These developments may usher in the next generation of compact, high-performance computational imaging systems,” the research team noted, “opening new possibilities in science, industry, and daily life.”

For further reading please visit: 10.1126/sciadv.adt3909