In Strater 2, click File | Import, draw a rectangle around where you want the image to be placed in the header or footer pane, select the desired image in the Import dialog, and click Open. The image is imported. You can move it around or resize it to exactly what you want.
Additionally, in any version of Strater you can copy and paste an image into the header and footer panes. Strater 1 does not support copying and pasting an image into the log pane.
Updated: October 4, 2016