A Mixed Media Reality (MMR) system and associated techniques are disclosed. The MMR system provides mechanisms for forming a mixed media document that includes media of at least two types (e.g., printed paper as a first medium and digital content and/or web link as a second medium). The present invention provides a system, method, and computer program product for modifying tie strength between members of an existing network using captured digital images of documents. Documents associated with the captured images are recognized and other members associated with the document are determined. Using this information, ties between members or the network are modified.