Requests can be made to any node in the network and only the required amount of work will be done. ImageVision speeds requests by caching the output of each node. Pieces of the requested region which are already in the cache will not be recomputed. This is especially useful for fan-out. When the parameters of an operator node change, the nodes which follow in the network must have their caches invalidated.
Nodes can compute in parallel.
For example, a so-called eager node can fill its cache with data that it expects will be needed later.