Impulsive Noise Reduction In Raman Spectroscopy Images

Charge-Coupled Device (CCD) detectors are becoming more popular in spectroscopy instrumentation. In spite of technological advances, spurious signals and noise are unavoidable in Raman spectroscopes. In general, the noise comes from two major sources, impulsive noise caused by high energy radiation from local or extraterrestrial sources (cosmic rays), and noise produced in Raman backscattering estimation. In this work, two algorithms for impulsive noise removal are presented, based in spectral and spatial features of the noise. The algorithms combine pattern recognition and classical filtering techniques to identify the impulses. Once an impulse has been identified, it is removed and substituted with data points having similar statistical properties as the surrounding data.