Optical information processing continues to prosper despite the competition from purely digital computer techniques. This conference attests to this fact but so does the current literature and particularly the recent books, including the two volumes in the series Topics in Applied Physics; Volume 23, edited by Casasent." (1978) and Volume 48, edited by Lee2 (1981). These two volumes contain a very good summary by many of the leading contributors to the field (Abramson,." Balasubramanian,' Casasent,192 Caulfield,' Considine,' Gonsalves,' Goodman,2 Knight,2 Lee,2 Leith,' Rhodes,2 Sawchuk,2 Thompson."). The even more recent book edited by Stark3 (1982) has contributions by nineteen authors. Textbooks have not been ignored either, with Gaskill's4 book in 1978 on Linear Systems and just a few weeks ago a new and much revised edition of Yu's book on Optical Information Processing5 (1983). The content of these volumes, particularly the first three, gives some overview of current trends in this field; each of the books deals of course with basic concepts (Lee,2 Casasent and Caulfield,' Stark3). Specific topics include chapters on biomedical applications (Caulfield1); radar (Leith,." King3); crystallography (Thompson 1); nondestructive testing (Abramson 1); photogrammetry (Balasubramanian 1); particle measurement (Anderson3); photographic image measurement (Shannon and Cheatham3). Techniques and methodology are also dealt with in some detail in each of these treatises, including complex spatial filtering (Almeida and Indebetouw3); hybrid systems (Leger and Lee,3 Casasent2); nonlinear processing (Sawchuk and Strand3); interface devices (Knight2); space-variant methods (Goodman,2 Rhodes3); incoherent techniques (Bartelt et al3; Rhodes and Sawchuk2).