Hi DavidG,

In fact to do that easily using the Color ROI plugin we need to implement a new ROI Descriptor counting the number of enclosed ROI. Currently there is not that kind of ROI Descriptor as Descriptors are supposed to compute a value relative to a specific ROI. Still that’s possible to do as the compute method from ROI descriptor interface receive have the Sequence information to compute its result (to compute intensity value for instance) so we could retrieve all ROI from the Sequence that way. Honestly that is not a very elegant way of doing that, a better way would be to have a new kind of ROI Descriptor computed against a list of ROI. Still at this point, it’s not probably too hurtful to try that (i’m just afraid about the computing time when you have many ROIs in your sequence).
We will probably give a shot about it soon as indeed it would be really useful to have that descriptor (intersected ROI / contained ROI) 🙂

Best,

– Stephane