For the purpose of locating people in aerial search and rescue operations, color-image based systems are excellent, but simply fall short when it comes to differentiating between actual human skin and objects with similar hues. To overcome this problem, researchers at the Air Force Institute of Technology (AFIT) have developed a novel two-dimensional feature space which uses the spectral absorption characteristics of melanin, hemoglobin and water to better characterize human skin.
Spectral imaging systems use information from the entire electromagnetic spectrum to provide digital images with much greater information per pixel than traditional cameras. Feature spaces in a spectral imaging system are vectors that numerically represent an object’s characteristics.
The AFIT research team used feature spaces to key in on specific constituents of human tissue by using a skin index concerned with how water and melanin’s presence in skin manifests at two different wavelengths in the near-infrared region. These changes would cut the overall cost of hyperspectral-based search and rescue systems to a seventh of what they currently cost.