Maximization of incoming messages

Maximization of incoming messages

guest (guest) 24 Apr 2017 19:41

We understood from the question that we need to compute the out going messages for each unobserved nodes, then use those messages to update in coming messages for unobserved neighbor nodes. When computing outgoing messages we need to find xi that maximizes [pairwise function * incoming messages]. How do we know what pixel maximizes the incoming messages? When computing outgoing nodes m_ij(xj), should we compute it for every possible value of xj? Alternatively, should we only compute one message for the current version of the pixel so that the maximization is independent on the incoming messages?
Thanks

Re: Maximization of incoming messages

Daniel Carmon 26 Apr 2017 15:43

Hi

1. "We understood from the question that we need to compute the out going messages for each unobserved nodes, then use those messages to update in coming messages for unobserved neighbor nodes." - The observed nodes also send messages that should (must) be computed.
2. "How do we know what pixel maximizes the incoming messages?" - I think that maybe your'e mixing between xi and Xi. Xi is a node which corresponds to a pixel, but xi is denoting a pixel value (between 0 and 255), so the argmax is straightforward to find.
3. "When computing outgoing nodes m_ij(xj), should we compute it for every possible value of xj?" - Yes. This should tell Xj what his neighbor Xi "thinks" of each possible assignment it (Xj) can have.