This document discusses various techniques for object recognition in digital images. It begins by defining object recognition and its goals. It then describes several important techniques for object recognition, including spatial relations, temporal relations, data retrieval in conventional databases, image extraction through mining, and content-based retrieval. For each technique, it provides examples and discusses how the technique can be used to recognize objects in images. The document concludes that object recognition can be improved by using contextual information and a knowledge base to classify segmented image regions.