Abstract: A spectral analysis surveillance system includes sources or emitters which emit various wavelengths of electromagnetic radiation or energy into a space under surveillance, and a sensor which produce signals indicative of electromagnetic energy returned by people and other objects in the space. The electromagnetic radiation may fall in the visible portion of the electromagnetic spectrum yet the energy is emitted to appear as either white light or a single color. Returned energy is analyzed against reference samples. The spectral analysis surveillance system may be part of an integrated surveillance system including other components, for example metal detectors, baggage X-ray scanners, full body imagers, etc., and may provide surveillance of private or public locations, for instance airports.

Abstract: A system employs combinations of marking media, each with respective distinguishing spectral characteristics to encode human comprehensible information in, and read human comprehensible information from, machine-readable indicia or symbols. Machine-readable indicia may be a single dot encoding information only in the combinations. Machine-readable symbols may be linear or two dimensional, spatially encoding information in the combinations, as well as spatially. A symbology may map at least the combinations to human-readable symbols or characters. A printer may form indicia or symbols with combinations of marking media. A reader may read indicia or symbols and decode information from at least the combinations of marking media. Different combinations may be visually homogenous, for example gray.

Abstract: Spectral information may be employed in process control and/or quality control of goods and articles. Spectral information may be employed in process control and/or quality control of media, for example financial instruments, identity documents, legal documents, medical documents, financial transaction cards, and/or other media, fluids for example lubricants, fuels, coolants, or other materials that flow, and in machinery, for example vehicles, motors, generators, compressors, presses, drills and/or supply systems. Spectral information may be employed in identifying biological tissue and/or facilitating diagnosis based on biological tissue.