  A novel technique for calibration transfer called the Modified Four Point
Interpolant (MFPI) method is introduced for near infrared spectra. The method
is founded on physical intuition and utilizes a series of quasiconformal maps
in the frequency domain to transfer spectra from a slave instrument to a master
instrument's approximated space. Comparisons between direct standardization
(DS), piecewise direct standardization (PDS), and MFPI for two publicly
available datasets are detailed herein. The results suggest that MFPI can
outperform DS and PDS with respect to root mean squared errors of transfer and
prediction. Combinations of MFPI with DS/PDS are also shown to reduce
predictive errors after transfer.
