Abstract
There has been a very rapid growth in the field of image processing in the past two decades, a growth which shows every prospect of accelerating. One witness to the current interest is the number of surveys and special issues of journals being devoted to the topic (Rosenfeld, 1969; IEEE Transactions — Computers, 1972; Proceedings of the IEEE, 1972a, 1972b; Graselli, 1969; Huang et al., 1971; Harmon and Knowlton, 1969; Andrews et al., 1972; Pattern Recognition, 1973; Hall et al., 1971; Proceedings of Seminar on Image Information Recovery, 1968; Proceedings of Conference on Machine Processing of Remotely Sensed Data, 1973; Arps, 1974). This growth is occurring both in the range of applications and in the variety of the techniques being employed.