  We describe an algorithm that takes as input an open book decomposition of a
closed oriented 4-manifold and outputs an explicit trisection diagram of that
4-manifold. Moreover, a slight variation of this algorithm also works for open
books on manifolds with non-empty boundary and for 3-manifold bundles over the
circle. We apply this algorithm to several simple open books, demonstrate that
it is compatible with various topological constructions, and argue that it
generalizes and unifies several previously known constructions.
