This book constitutes the refereed proceedings of the First International Conference on Semantics and Digital Media Technologies, SAMT 2006, held in Athens, Greece in December 2006. The 17 revised full papers presented together with a invited keynote paper were carefully reviewd and selected from 68 submissions. SAMT 2006 targets to narrow the `Semantic Gap', i.e. the large disparity between the low-level descriptors that can be computed automatically from multimedia content and the richness and subjectivity of semantics in user queries and human interpretations of audiovisual media. The papers address a wide area of integrative research on new knowledge-based forms of digital media systems, semantics and low-level multimedia processing.