Detecting organic materials with a CCD camera

Absorption bands in the near-infrared are used to detect materials composed of organic molecules, in scenes imaged with a conventional CCD camera. A simple model of reflectance spectra (between 850 and 980 nm) is proposed and tested on a wide range of materials. An existing vision system that was designed to detect materials with high water content is tested on organic materials. The system cannot detect materials (such as cellulose and starch) that consist of chains of sugars. It is able to robustly detect materials such as fats and aliphatic plastics (in their pure form), whose molecules are essentially long chains of CH(2) and CH(3) groups. The ability of the system to detect plastic objects is limited by inorganic additives in the plastics.