​NTU scientists take multi-coloured images with a lensless camera

A new camera technology developed by scientists from Nanyang Technological University, Singapore (NTU Singapore) can take sharp, colour images without using a lens and colour filters.

Using only a piece of ground glass and a monochrome sensor, the scientists created multi-coloured images by ‘reverse engineering’ the light that is scattered by the translucent matt surface of the ground glass, thus obtaining the original image that was projected on to it.

Since different wavelengths of light are scattered differently by the ground glass, the NTU scientists created an algorithm to reconstruct the image. To do this they created a library of ‘speckle patterns’ linked to each wavelength of light, including those in the infrared and ultraviolet spectrums which are not visible to the naked eye.
In a conventional camera, optics made from glass or plastic lenses capture light and guide it onto the colour filters and camera sensor to obtain sharp colour images. These lenses are usually bulky in size and expensive due to the precision manufacturing required.

By removing the need for a lens and colour filters and replacing them with ground glass, this innovation could potentially be applied to compact cameras and smart phones to make them slimmer.