ATLAS

ATLAS is intended to generalize the annotation graph and differs in two main ways. First, it allows richer relationships between annotation and signal. In annotation graphs, the only relationship between annotation and signal that is supported in the data handling is the timespan on the signal to which the annotation refers, given as a start and end time. NXT is similar to AGTK in this regard. ATLAS, however, defines more generic signal regions which can refer to other properties besides the timing. For example, on a video signal, a region could pinpoint a screen location using X and Y coordinates. Second, ATLAS explicitly represents structural relationships by allowing annotations to name a set of "children", without constraining how many "parents" an annotation may have. The framework for defining the semantics of this relationship and for specifying which types of annotations expect which other types as children, MAIA, is still under development. It has the potential to be very flexible, especially if the semantics of the parent-child relationship can vary depending on the types of data objects that they link. The ATLAS data model is implemented in Java, and the developers plan both a query language and direct support for writing graphical user interfaces.