From the command line in the folder with the .edf files type image_math_petra [stem name] [first file] [last file] [operation]

Example:

image_math_petra fcc_1_ 0 111 median

Output files of the median operation:

fcc_1_m10000.edf (average)

fcc_1_m20000.edf (median)

fcc_1_m30000.edf (some other more sophisticated median)

We proceed with the “normal” median (file no. 2). In Fabian go to Image, then to Correction, then to Background Correction and load the median file (in this example fcc_1_m20000.edf)