A window is applied to {HEAD ~ the spectral image data} along the λ dimension, to select {TAIL ~ a subset} of the spectral image data corresponding to a range of wavelengths 
A window is applied to { HEAD ~ the spectral image data } along the λ dimension , to select { TAIL ~ a subset } of the spectral image data corresponding to a range of wavelengths
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH