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")

Load and prepare the data

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

Select the useful spectral region:

nd = dataset[:, 60.0:]

Plot the original data:

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

Detrend for easier comparison:

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

Denoise with default parameters

The default ratio is 99.8:

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

Denoise with different ratios

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

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

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Denoising increases the signal-to-noise ratio effectively but has limited effect on cosmic ray spikes. Consider using despike methods for those.

# Uncomment the following line to display all figures when running the script
# directly with Python.
#
# scp.show()