Dear Stéphane,

Thank you for your answer. I had forgotten this Ctrl key!! Is there any possibilities to keep the information about the channel used when the selection is done?

In the mean time, I used the manual counting plugin for detection (1 color for 1 channel) and use ROI colors  to count detection corresponding to a channel. However, it would be easier (and limit mistakes especially when channels used are not necessary the same) if we could keep channel information when the selection is done.

take care.

Stéphane