Hi Katie,

Channel information from ROI are somehow independent from your image. Usually when you use a plugin which generate ROIs, it sets the channel information of the ROI on the channel where the detection /segmentation was made. Sometime it doesn’t, it just set the ROI channel information to -1 (means all channel) in which was you can’t filter on mean intensity descriptor as it requires to know on which channel you compute the mean intensity.

To fix that, you can insert the “set ROI Position C” block (position C means Channel here) before applying filtering so you set it on channel where you want to compute the means intensity (for instance channel 0).
Hope you understand my explanations !

Best,

– Stephane

Image cOh yeh