Provider: ingentaconnect
Database: ingentaconnect
Content: application/x-research-info-systems
TY - ABST
AU - Bhargava, Rohit
AU - Wang, Shi-Qing
AU - Koenig, Jack L.
TI - Route to Higher Fidelity FT-IR Imaging
JO - Applied Spectroscopy
PY - 2000-04-01T00:00:00///
VL - 54
IS - 4
SP - 486
EP - 495
N2 - FT-IR imaging employing a focal plane array (FPA) detector is often plagued by low signal-to-noise ratio (SNR) data. A mathematical transform that re-orders spectral data points into decreasing order of
SNR is employed to reduce noise by retransforming the ordered data set using only a few relevant data points. This approach is shown to result in significant gains in terms of image fidelity by examining
microscopically phase-separated composites termed polymer dispersed liquid crystals (PDLCs). The actual gains depend on the SNR characteristics of the original data. Noise is reduced by a factor greater
than 5 if the noise in the initial data is sufficiently low. For a moderate absorbance level of 0.5 a.u., the achievable SNR by reducing noise is greater than 100 for a collection time of less than 4 min.
The criteria for optimal application of a noise-reducing procedure employing the minimum noise fraction (MNF) transform are discussed and various variables in the process quantified. This noise reduction
is shown to provide high-quality images for accurate morphological analysis. The coupling of mathematical transformation techniques with spectroscopic Fourier transform infrared (FT-IR) imaging is shown
to result in high-fidelity images without increasing collection time or drastically modifying hardware. Index Headings: Fourier transform infrared microspectroscopy; Imaging; Minimum noise fraction; Principal
components; Signal-tonoise ratio; Morphological analysis; Polymer dispersed liquid crystals.
UR - http://www.ingentaconnect.com/content/sas/sas/2000/00000054/00000004/art00007
M3 - doi:10.1366/0003702001949898
UR - http://dx.doi.org/10.1366/0003702001949898
ER -