![]() This reflection may misconstrue the true reading of the objects’ inherent radiation. Sometimes the surface of the target may reflect infrared energy. These signatures are less pronounced in hyperspectral systems (which image in many more bands than multispectral systems) and when exposed to wind and, more dramatically, to rain. Every material has an infrared signature that aids in the identification of the object. The brightness of the image produced by a thermal imager depends on the objects emissivity and temperature. ![]() Because mid-wave infrared (MWIR) and long wave infrared (LWIR) technologies measure radiation inherent to the object and require no external light source, they also are referred to as thermal imaging methods. This FPA allowed researchers to look at two infrared (IR) planes at the same time. In 2003, researchers at the United States Army Research Laboratory and the Federal Laboratory Collaborative Technology Alliance reported a dual band multispectral imaging focal plane array (FPA). Multispectral imaging measures light emission and is often used in detecting or tracking military targets. Hyperspectral imaging is a special case of spectral imaging where often hundreds of contiguous spectral bands are available. Multispectral imaging measures light in a small number (typically 3 to 15) of spectral bands. Multispectral imaging has also found use in document and painting analysis. Early space-based imaging platforms incorporated multispectral imaging technology to map details of the Earth related to coastal boundaries, vegetation, and landforms. It was originally developed for military target identification and reconnaissance. It can allow extraction of additional information the human eye fails to capture with its visible receptors for red, green and blue. The wavelengths may be separated by filters or detected with the use of instruments that are sensitive to particular wavelengths, including light from frequencies beyond the visible light range, i.e. Multispectral imaging captures image data within specific wavelength ranges across the electromagnetic spectrum. The bright yellow patches in other parts of the image are hollows. The results also showed systematic differences between the four ethnic groups, between eight body locations, between two genders, and between the measurements from the three instruments.Multispectral image of Bek crater and its ray system on the surface of Mercury, acquired by MESSENGER, combining images at wavelengths of 996, 748, 433 nm. It was found that two scales: whiteness-depth, and blackness-vividness could well describe these distributions. The colorimetric data calculated from the spectral measurements revealed similar patterns to describe the colour distribution of each skin group. ![]() Those from the tele-spectroradiometer had an increase from 600 nm while the others were flatter. They all showed the “W” shape between the 550 nm and 580 nm as found by the other studies. The spectral reflectance results were first compared. ![]() Eight locations for each subject were measured. They were used to measure 47 subjects who were divided into four skin groups: Chinese, Caucasian, South-Asian, and Dark. Three different colour measuring instruments were used: a tele-spectroradiometer, a de:8° and a 45°:0° spectrophotometers. This article focuses on human skin colour.
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