Publisher Summary There is no similar data model or algebra dedicated to image databases. This chapter develops a model of image algebra, modeled on relational algebra. This data model depends crucially on scoring functions that orders the set of images with respect to a given query. The manipulation of these functions is an integral part of the query process. Scoring functions as a data type and an algebra for manipulating them are described in the chapter. Further, a complete data model is defined in which images and features can be defined as data types and manipulated.