Spectral regions

You can average up a number of files in the pre-edge region for a single $I_{0}$ image, and a number of files in a post-edge region for a single $I$ image (you can also use just one file for each spectral region). This lets you get a very high signal-to-noise ratio for making a map of the element of interest. You can also add up images over a XANES peak. To define the region, you click on the Define button, and then click and drag the mouse over the spectral region of interest (see Fig. 6). You can look at the I or I0 average image, or the -log(ratio) image of $-\log(I/I_{0})$; see Fig. 7.

Figure 6: Spectral regions. After defining such regions, you can calculate a thickness map as is shown in Fig. 7.

Figure 7: Optical density map $\mbox{OD}=-\log(I/I_{0})$ calculated from the spectral regions shown in Fig. 6.