I hope this is a quick question to answer.
I believe from my testing that the IImageRect isn’t supported/implemented for devices using the GenTL (3rd Gen Stack).
Is this correct?
Is there an alternative method for changing the image size being acquired?
Sorry for the late response due to the vacation season!
In GentTL you need to set the new image size in the camera NodeMap and then call the function RegisterManagedFlowSetPool. For more details please see the following contribution in our forum: https://forum.commonvisionblox.com/t/how-to-update-driver-memory-after-changing-camera-parameters/1526/9