Advances in hyperspectral image projection
Images taken by remote-sensing instruments may include data in many spectral bands, not the minimum complement of three used by common digital cameras (i.e., “red,” “green,” and “blue”). Instruments collecting data in hundreds or thousands of narrow spectral bands are referred to as “hyperspectral,” and provide vital, detailed data for study.
Research pertaining to climate change, as an example, requires comprehensive knowledge about a hyperspectral imager’s performance. PL scientists have made progress in developing appropriate diagnostics through the use a Hyperspectral Image Projector (HIP). Using this instrument, scientists can generate images in the laboratory with precisely tailored spectra for each pixel, simulating actual scenes in nature.
To demonstrate this capability, researchers chose a hyperspectral image of a coral reef located off the coast of Puerto Rico and acquired by an airborne hyperspectral sensor. This image, provided by the University of Puerto Rico at Mayagüez, is an ideal subject for emulating a spectrally and spatially complex scene. The PL scientists recreated the image using the HIP, and recollected the image using a laboratory imaging spectrometer as a proxy for the type of devices used in the field.
This demonstration also helped show the HIP’s potential for other applications. A HIP could be used to determine the threshold of detection of changes in scenes. This is a key area of concern for measurement of regional and global climate change. The HIP may also serve as a tool in the development of medical imaging by providing a standard tissue phantom for medical imagers.
For further information, see Hyperspectral projection of a coral reef scene using the NIST hyperspectral image projector.
An false-color image of a coral reef projected by the Hyperspectral Image Projector (HIP) (above) and a plot of the basis functions that formed the projected hyperspectral image (below).