I have tried to find out from the PDF specification what a bead is, but I haven't foudn a clear account. (That may be my fault or it may be the size of the spec!). My understanding is that beads give the reading order of chunks of the document (independently of the coordinate system).
Here are some questions. If they are wildly ignorant please correct me gently. * Where and how are beads created? Are they only created by authoring software or can readers deduce them? * where is bead information stored in a PDF and how can it be extracted? * are PDF readers expected to implement bead-aware software? What is the abstract model of a bead in a reader? * are there other ways of transmitting "chunks" other than beads? TIA P. -- Peter Murray-Rust Reader Emeritus in Molecular Informatics Unilever Centre, Dept. Of Chemistry University of Cambridge CB2 1EW, UK +44-1223-763069
