Open the program by going to the folder where the processed data is stored. Now open the program by typing the following to the Konsole:

  ImageD11_gui.py

ImageD11 is written and maintained by John Wright from ESRF and has an extensive manual available here https://pythonhosted.org/ImageD11/.

The program should open. In ImageD11 go to Transformation, then Load filtered peaks and choose the .flt file you would like to see (You automatically should be in the right folder.).

Then go to Transformation and plot y/z. You should see a 2D diffraction image of all the spots which passed the threshold. From now on, we call this image diffraction plot. You should remember, which file you opened, because ImageD11 doesn't show this anywhere.

ImageD11 can show only one diffraction plot at once. If you want to compare two (or more) diffraction plots, you can either save the plots (as .png file) or open a new ImageD11 in a new tab of the Konsole.