Similarity engine for content-based retrieval of images

A search engine, comprising:

• a set of primitives each having one or more functions capable of extracting attributes from a visual object and capable of determining similarity between visual objects;
• a registration interface capable of registering the primitives;
• and
• a comparator function capable of applying functions of registered primitives so as to compare objects.

In a system comprising a search engine in communication with a database including a plurality of visual objects, a method of object comparison, comprising the steps of:

• creating a custom primitive having an analysis function and a comparison function;
• registering the custom primitive with the search engine via a registration interface;
• applying the analysis function to at least a portion of the database objects and a query object;
• and
• applying the comparison function to the analyzed query object and at least a portion of the analyzed database objects.

A method of extending a search engine for searching a database of visual objects, the method comprising the steps of:

• providing a search engine primitive including a function to extract an attribute from a visual object;
• adding a new primitive to the search engine via a registration interface, wherein the new primitive comprises a comparison function for a selected attribute;
• and
• comparing the extracted attributes from two visual objects with the comparison function.