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). In one particular...http://www.google.com.tw/patents/US7917554?utm_source=gb-gplus-share專利 US7917554 - Visibly-perceptible hot spots in documents
