A new imaging system is capable of obtaining up to twelve times more color information than the human eye and conventional cameras, which implies a total of 36 color channels.

The system involves a new generation of sensors in combination with a matrix of multispectral filters to improve their performance. 

 Color image sensors can be found in all common types of digital cameras and devices. They have an architecture that consists of a monochrome sensor (in black and white), covered with a layer of color filters (commonly, red, green and blue - RGB). This architecture only extracts information from one of these three colors in each pixel within the image. To extract the information from the rest of colors in each pixel, it is necessary to apply algorithms which in most cases are among manufacturers' best-kept secrets. 

According to the Principal Investigator Miguel Ángel Martínez Domingo, "the new sensors developed at the Polytechnic University of Milan are called Transverse Field Detectors (TFD) and they are capable of extracting the full color information from each pixel in the image without the need for a layer of color filter on them.

"In order to do so, they take advantage of a physical phenomenon by virtue of which each photon penetrates at a different depth depending on its wavelength, i.e., its color. In this way, by collecting these photons at different depths on the silice surface of the sensor, the different channels of colour can be separated without the necessity of filters."

New applications for the TFD

This particular advantage has already been put to good use in previous cases, such as the X3 of Foveon Inc (USA). However, what is new about TDF is the fact that, by applying a transversal electric field of varying and controlled intensity, "we can modulate the depth at which the photons in each color channel are collected. This offers the possibility of fine tuning the way in which these sensors turn the light they receive into electric signals," says Martínez Domingo.

He adds that these type of sensors can facilitate "numerous applications in very different fields of research"

"Multispectral images open an endless series of possibilities within the most diverse fields of science: medical imaging, remote sensing, satellite images, military and defense technology, industrial applications, robotic vision, assisted or automatic driving, and a long etcetera of potential uses which attracts the increasing interest of ever more scientifics and engineers from different specialities. To study the way in which light interacts with our environment can give us very valuable information on its behaviour in a totally innocuous and noninvasive way."