HADAMARD-TRANSFORM AND FOURIER-TRANSFORM INFRARED IMAGING AND SPECTROMETRY

A moving (mechanical) two-dimensional Hadamard encoding mask has been employed with a Fourier-transform infrared (FT-IR) spectrometer to com bine imaging in two spatial dimensions with the spectral dimension as a form of three-dimensional spectrometry in the mid-infrared and near- infrared spectral regions. Chemical images at chosen wavenumbers and m id-infrared spectra of individual pixel positions in the image have be en obtained with acceptable signal-to-noise ratios and reasonable data -acquisition times.