In this paper a novel "Smart Media" concept for semantic-based multimedia security and management is proposed. This concept is based on interactive object segmentation (considered as side information in visual human-computer interface) with hidden object-based annotations. Information-theoretic formalism is introduced that considers the human-computer interface as a multiple access channel. We do not consider an image as a set of pixels but rather as a set of annotated regions that correspond to objects or their parts, where these objects are associated with some hidden descriptive text about their features. The presented approach for "semantic" segmentation is addressed by means of the human-computer interface that allows a user to easily incorporate information related to image objects and to store them in a secure way. Since each selected image object carries its own embedded description, this makes it self-containing and formally independent from the particular image format used for storage in image databases. The proposed object-based hidden descriptors are invariant to changes of image filename or/and image headers, and are resistant to object cropping/insertion operations, which are usual in multimedia processing and management. This is well harmonized with the "Smart Media" concept where the image contains additional information about itself, and where this information is securely integrated inside the image while remaining perceptually invisible.