Picture recognition and analysis has numerous applications in all fields of technology, from medical diagnosis to document processing. This paper introduces some of the basic techniques of picture analysis:correlation, or matching of pictures;transformationsand their uses, including their application tonormalizationfor recognition purposes;parametrization, or property measurement, for picture classification; andsegmentationof a picture into parts for purposes of description, with emphasis on segmentation based on regionconnectivity. Examples are given showing how each of these techniques is important in practical applications.