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

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")

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()