First a file (by default called imageslist.txt) with the list of images to be displayed should be created. Typically:
rm -rf imageslist.txt ; ls img > imageslist.txt
The row column can be selected using the -addRowTableVariable option.
pageCreator will look for a string in the image name after the row variable, until it finds an underscore "_".
For example, if the row variable is "cut", we have this images:
img/cut-field-strength1_sector-1.png
img/cut-field-strength2_sector-1.png
then there will be two rows: "field-strength1" and "field-strength2".