Denoising a 2D Raman spectrum

In this example, we use the denoise method to remove the noise from a 2D Raman spectrum.

Import spectrochempy

import spectrochempy as scp

scp.set_loglevel("INFO")  # to see information

Load the data (should be a 2D spectrum or a list of datasets that can be merged):

dataset = scp.read("ramandata/labspec/serie190214-1.txt")

select the useful region

nd = dataset[:, 60.0:]

Basic plot

_ = nd.plot(title="original data")

Detrend the data (for a easier comparison)

nd1 = nd.detrend(title="detrended data")
_ = nd1.plot()

Denoise the data using the denoise method with the default parameters i.e., ratio=99.8

nd2 = nd1.denoise()
_ = nd2.plot(title="denoised data")

Denoise the data using a different ratio

nd3 = nd1.denoise(ratio=95)
_ = nd3.plot(title="denoised data")


nd4 = nd1.denoise(ratio=90)
_ = nd4.plot(title="denoised data")

• 
• 

This example shows that denoising can be used effectively on such spectra to increase the signal-to-noise ratio. However, it apparently has a poor effect on eliminating cosmic ray peaks. For the latter, it may be useful to use despike methods as seen in another example.

This ends the basic example of denoising a 2D Raman spectrum.

# scp.show()  # uncomment to show plot if running from a script