Kai, just a note for "clarification": I wrote a full processing module containing 5 or 6 (don't have it here) to perform calibration and analysis of two filter and one filter fluorescence images. So, even when the standard PI modules may not perform the work you want, creating a new module is a very feasible project. I may even supply part of the code, or work with you in this project to create the needed software. If you read the paper, keep in mind that every step/process in there was performed in PI with those custom processes.