<title>Practical Phase Retrieval</title>

Abstract

This paper summarizes the current experience with phase retrieval at the University of Canterbury. While Fienup's algorithms need no modification for handling computer generated intensities corresponding to images that exhibit strong contrast, they must be extended to obtain satisfactory reconstruction of low contrast images. These same extensions, which have been incorporated into a composite computational procedure, tend also to be necessary when the given data are measured or are reduced from observations. The several steps in the procedure as it presently stands are described and discussed. Other steps, which are needed to widen the class of practically recoverable images and to make the procedure more objective, are suggested.