Spectrum Image Example
How to load a spectrum
image and plot the sum spectrum.
1. Open the spectrum image. Usually, this is done with the File
/ Open menu in the Lispix
- The Multi spect - whole cube takes
more time, and shows four additional plots (derived spectra) which are likely
to show features in the data that the Sum Spectrum does not show. I
use this immediately after opening a spectral image to get a quick overview
of its contents.
- The multi-spectrum-plot above has been expanded by dragging the bottom edge
of the plot downwards. The buttons across the bottom show or hide the
- All of these plots have been normalized to 1.0. You can display them
separately in their own plot with the counts in the y-axis, by using their
- Sum: sum spectrum for whole cube. Each point represents
an image from a particular channel, or x-ray energy. The value at
any point or channel number, is the sum of the pixel values for that image.
- Max: analogous to sum, except that the value is the maximum value
for the image.
- Log sum: log of the sum spectrum above.
- Log running sum and running max. These are analogous to the Log
sum and Max plots, except they are taken from a running-sum spectrum image,
where each image plane is the running sum of 10 consecutive images.
The peaks are smoothed considerably and broadened a little.
- In order to save memory, the running-sum spectrum image is not saved
- To see a running sum cube for any N consecutive images, use Cube
/ running sum